From d3a1cc80fb6c80e97ee554e5b40e18af03edcf84 Mon Sep 17 00:00:00 2001
From: Daniel Chalmers <daniel.chalmers@outlook.com>
Date: Thu, 24 Sep 2026 07:23:11 -0500
Subject: [PATCH 1/8] Remove the unused render-progress state

IsRendering and RenderProgress were never set outside a test, so the loading overlay always read "Loading..." with an indeterminate bar. The overlay now says so directly, which keeps the dead state from being carried into the view-model split.
---
 SentryDeck.Tests/MainWindowViewModelTests.cs | 19 -------------------
 SentryDeck/MainWindow.xaml                   |  6 ++----
 SentryDeck/MainWindowViewModel.cs            | 20 --------------------
 3 files changed, 2 insertions(+), 43 deletions(-)

diff --git a/SentryDeck.Tests/MainWindowViewModelTests.cs b/SentryDeck.Tests/MainWindowViewModelTests.cs
index 30bd128..666ee68 100644
--- a/SentryDeck.Tests/MainWindowViewModelTests.cs
+++ b/SentryDeck.Tests/MainWindowViewModelTests.cs
@@ -388,7 +388,6 @@ public void Loading_ShowsStatusOverlay_AndHidesVideo()
 
         vm.ShowStatusOverlay.ShouldBeTrue();
         vm.ShowVideoHosts.ShouldBeFalse();
-        vm.IsIndeterminateProgress.ShouldBeTrue();
     }
 
     [Fact]
@@ -461,24 +460,6 @@ public void PlayPauseIcon_ReflectsPlaybackState(bool isPlaying, string expectedI
         vm.PlayPauseIcon.ShouldBe(expectedIcon);
     }
 
-    [Fact]
-    public void LoadingStatusText_ShowsRenderProgressWhileRendering()
-    {
-        var vm = CreateViewModel();
-        vm.IsLoading = true;
-
-        vm.LoadingStatusText.ShouldBe("Loading...");
-        vm.IsIndeterminateProgress.ShouldBeTrue();
-
-        vm.IsRendering = true;
-        vm.RenderProgress = 0.5;
-
-        vm.RenderProgressPercent.ShouldBe(50);
-        vm.LoadingStatusText.ShouldBe("Rendering... 50%");
-        // A determinate render progress bar replaces the indeterminate spinner.
-        vm.IsIndeterminateProgress.ShouldBeFalse();
-    }
-
     [Fact]
     public void UpdateBadge_DefaultsToUpToDate()
     {
diff --git a/SentryDeck/MainWindow.xaml b/SentryDeck/MainWindow.xaml
index d36c960..e59da54 100644
--- a/SentryDeck/MainWindow.xaml
+++ b/SentryDeck/MainWindow.xaml
@@ -1236,16 +1236,14 @@
 
                             <!--  Loading / rendering status  -->
                             <StackPanel Visibility="{Binding IsLoading, Converter={local:BoolToVisibilityConverter}}">
-                                <TextBlock Text="{Binding LoadingStatusText}"
+                                <TextBlock Text="Loading..."
                                            Margin="0,0,0,16"
                                            HorizontalAlignment="Center"
                                            Foreground="{DynamicResource TextFillColorPrimaryBrush}"
                                            Style="{StaticResource AppSubtitle}" />
                                 <ProgressBar Width="300"
                                              Height="6"
-                                             IsIndeterminate="{Binding IsIndeterminateProgress}"
-                                             Maximum="100"
-                                             Value="{Binding RenderProgressPercent, Mode=OneWay}" />
+                                             IsIndeterminate="True" />
                             </StackPanel>
 
                             <!--  Error / first-run empty state  -->
diff --git a/SentryDeck/MainWindowViewModel.cs b/SentryDeck/MainWindowViewModel.cs
index 2195a39..eaf1637 100644
--- a/SentryDeck/MainWindowViewModel.cs
+++ b/SentryDeck/MainWindowViewModel.cs
@@ -233,8 +233,6 @@ public string PositionText
 
     public bool HasNoClipSelected => SelectedClip is null && !IsLoading && !ShowErrorOverlay;
 
-    public bool IsIndeterminateProgress => IsLoading && !IsRendering;
-
     public bool IsGridViewSelected => SelectedCameraView == GridCameraView;
 
     public bool IsSingleCameraViewSelected => !IsGridViewSelected;
@@ -256,12 +254,6 @@ public string PositionText
         _ => CameraNames.DisplayName(camera),
     };
 
-    public string LoadingStatusText => IsRendering
-        ? $"Rendering... {RenderProgressPercent}%"
-        : "Loading...";
-
-    public int RenderProgressPercent => (int)(RenderProgress * 100);
-
     // --- Seek-bar overlays for the selected clip (event moment + chunk seams + gaps) ---
     // Recomputed whenever the selection changes or the controller opens/replaces its media source; plain fields (not ObservableProperty) because they're derived, not independently settable.
     private double? _eventPosition;
@@ -412,8 +404,6 @@ public string SelectionDurationText
     [ObservableProperty]
     [NotifyPropertyChangedFor(nameof(CanPlayPause))]
     [NotifyPropertyChangedFor(nameof(CanStop))]
-    [NotifyPropertyChangedFor(nameof(LoadingStatusText))]
-    [NotifyPropertyChangedFor(nameof(IsIndeterminateProgress))]
     [NotifyPropertyChangedFor(nameof(ShowStatusOverlay))]
     [NotifyPropertyChangedFor(nameof(ShowVideoHosts))]
     [NotifyPropertyChangedFor(nameof(HasNoClipSelected))]
@@ -427,22 +417,12 @@ public string SelectionDurationText
     [NotifyCanExecuteChangedFor(nameof(ExportSelectionCommand))]
     private bool _isLoading;
 
-    [ObservableProperty]
-    [NotifyPropertyChangedFor(nameof(LoadingStatusText))]
-    [NotifyPropertyChangedFor(nameof(IsIndeterminateProgress))]
-    private bool _isRendering;
-
     // True while the clip list is being (re)scanned from disk; drives the sidebar loading indicator.
     [ObservableProperty]
     [NotifyCanExecuteChangedFor(nameof(RefreshClipsCommand))]
     [NotifyCanExecuteChangedFor(nameof(OpenFolderCommand))]
     private bool _isLoadingClips;
 
-    [ObservableProperty]
-    [NotifyPropertyChangedFor(nameof(RenderProgressPercent))]
-    [NotifyPropertyChangedFor(nameof(LoadingStatusText))]
-    private double _renderProgress;
-
     [ObservableProperty]
     [NotifyPropertyChangedFor(nameof(PositionText))]
     private double _seekPosition;

From 0f25e99a33261c20c020b553194898fdfe8f38e5 Mon Sep 17 00:00:00 2001
From: Daniel Chalmers <daniel.chalmers@outlook.com>
Date: Thu, 24 Sep 2026 07:30:04 -0500
Subject: [PATCH 2/8] Move the error overlay into its own view-model

The first step of splitting MainWindowViewModel by feature. ErrorOverlayViewModel owns the notice that covers the video area (title, details, dismissability, the first-run empty state, and the FFmpeg download prompt), and every feature reports through the one instance the main window owns. The overlay-visibility logic that combines errors with loading and selection state stays on the main view-model.
---
 .../MainWindowViewModelTests.Clips.cs         |  30 ++---
 .../MainWindowViewModelTests.Playback.cs      |   8 +-
 .../MainWindowViewModelTests.Trimming.cs      |  12 +-
 SentryDeck.Tests/MainWindowViewModelTests.cs  |  28 ++---
 SentryDeck/MainWindow.xaml                    |  20 ++--
 SentryDeck/MainWindowViewModel.cs             | 104 ++++++------------
 .../ViewModels/ErrorOverlayViewModel.cs       |  52 +++++++++
 7 files changed, 137 insertions(+), 117 deletions(-)
 create mode 100644 SentryDeck/ViewModels/ErrorOverlayViewModel.cs

diff --git a/SentryDeck.Tests/MainWindowViewModelTests.Clips.cs b/SentryDeck.Tests/MainWindowViewModelTests.Clips.cs
index 98e9a63..e8df1b2 100644
--- a/SentryDeck.Tests/MainWindowViewModelTests.Clips.cs
+++ b/SentryDeck.Tests/MainWindowViewModelTests.Clips.cs
@@ -148,10 +148,10 @@ public async Task LoadClips_WithNoRoots_ShowsDismissibleEmptyState()
         await vm.LoadClipsAsync([]);
 
         // First run with no USB drive attached: a friendly prompt the user can dismiss to reach the rest of the app, not a scary error they're stuck behind.
-        vm.ErrorTitle.ShouldBe("No dashcam footage yet");
-        vm.IsEmptyState.ShouldBeTrue();
-        vm.CanDismissError.ShouldBeTrue();
-        vm.ShowErrorOverlay.ShouldBeTrue();
+        vm.Error.Title.ShouldBe("No dashcam footage yet");
+        vm.Error.IsEmptyState.ShouldBeTrue();
+        vm.Error.CanDismiss.ShouldBeTrue();
+        vm.Error.IsVisible.ShouldBeTrue();
         vm.ShowStatusOverlay.ShouldBeTrue();
         vm.ClipCount.ShouldBe(0);
     }
@@ -164,10 +164,10 @@ public async Task LoadClips_AccessDenied_ShowsAccessDeniedError()
         await vm.LoadClipsAsync([@"D:\TeslaCam"]);
 
         // A permissions problem gets its own title and remedy; it isn't the empty state.
-        vm.ErrorTitle.ShouldBe("Access Denied");
-        vm.ErrorDetails.ShouldContain(@"D:\TeslaCam");
-        vm.ShowErrorOverlay.ShouldBeTrue();
-        vm.IsEmptyState.ShouldBeFalse();
+        vm.Error.Title.ShouldBe("Access Denied");
+        vm.Error.Details.ShouldContain(@"D:\TeslaCam");
+        vm.Error.IsVisible.ShouldBeTrue();
+        vm.Error.IsEmptyState.ShouldBeFalse();
     }
 
     [Fact]
@@ -178,9 +178,9 @@ public async Task LoadClips_LoaderThrows_ShowsGenericLoadError()
         await vm.LoadClipsAsync([@"E:\TeslaCam"]);
 
         // Both halves matter for a bug report: which folder failed, and what the failure was.
-        vm.ErrorTitle.ShouldBe("Error Loading Clips");
-        vm.ErrorDetails.ShouldContain(@"E:\TeslaCam");
-        vm.ErrorDetails.ShouldContain("the drive was removed");
+        vm.Error.Title.ShouldBe("Error Loading Clips");
+        vm.Error.Details.ShouldContain(@"E:\TeslaCam");
+        vm.Error.Details.ShouldContain("the drive was removed");
     }
 
     [Fact]
@@ -203,8 +203,8 @@ public async Task LoadClips_OneRootFails_KeepsClipsFromTheHealthyRoot()
 
         // Scanning is per-root: one unreadable drive reports itself but must not cost the user the library on the drive that is still plugged in.
         vm.ClipCount.ShouldBe(2);
-        vm.ShowErrorOverlay.ShouldBeTrue();
-        vm.ErrorTitle.ShouldBe("Error Loading Clips");
+        vm.Error.IsVisible.ShouldBeTrue();
+        vm.Error.Title.ShouldBe("Error Loading Clips");
     }
 
     // --- Delete to Recycle Bin: the injectable confirm/recycle delegates keep this off the shell ---
@@ -318,8 +318,8 @@ public async Task DeleteClip_WhenRecycleFails_ShowsError_AndKeepsClip()
         var target = vm.FilteredClips[0];
         await vm.DeleteClipCommand.ExecuteAsync(target);
 
-        vm.ShowErrorOverlay.ShouldBeTrue();
-        vm.ErrorTitle.ShouldBe("Delete Failed");
+        vm.Error.IsVisible.ShouldBeTrue();
+        vm.Error.Title.ShouldBe("Delete Failed");
         vm.ClipCount.ShouldBe(2);
         vm.FilteredClips.ShouldContain(target);
     }
diff --git a/SentryDeck.Tests/MainWindowViewModelTests.Playback.cs b/SentryDeck.Tests/MainWindowViewModelTests.Playback.cs
index 6341f12..613c337 100644
--- a/SentryDeck.Tests/MainWindowViewModelTests.Playback.cs
+++ b/SentryDeck.Tests/MainWindowViewModelTests.Playback.cs
@@ -158,9 +158,9 @@ public void ControllerError_ShowsErrorOverlay()
 
         controller.ErrorMessage = "decode failed";
 
-        vm.ShowErrorOverlay.ShouldBeTrue();
-        vm.ErrorTitle.ShouldBe("Playback Error");
-        vm.ErrorDetails.ShouldBe("decode failed");
+        vm.Error.IsVisible.ShouldBeTrue();
+        vm.Error.Title.ShouldBe("Playback Error");
+        vm.Error.Details.ShouldBe("decode failed");
     }
 
     [Fact]
@@ -186,7 +186,7 @@ public void SelectingClip_NotYetOpened_ShowsLoadingWithoutAnError()
         // The clip is intentionally NOT in the controller's playlist, so GoToClipAsync is a deterministic no-op; this verifies only that selection triggers the auto-play loading state.
         // Opening media is VideoPlayerController's own job.
         vm.IsLoading.ShouldBeTrue();
-        vm.ShowErrorOverlay.ShouldBeFalse();
+        vm.Error.IsVisible.ShouldBeFalse();
     }
 
     [Fact]
diff --git a/SentryDeck.Tests/MainWindowViewModelTests.Trimming.cs b/SentryDeck.Tests/MainWindowViewModelTests.Trimming.cs
index 59e1f55..b720c43 100644
--- a/SentryDeck.Tests/MainWindowViewModelTests.Trimming.cs
+++ b/SentryDeck.Tests/MainWindowViewModelTests.Trimming.cs
@@ -248,7 +248,7 @@ public void ExportSelection_SaveDialogCanceled_DoesNotExport()
         RunPinnedToTestThread(() => vm.ExportSelectionCommand.ExecuteAsync(null));
 
         exporter.Requests.ShouldBeEmpty();
-        vm.ShowErrorOverlay.ShouldBeFalse();
+        vm.Error.IsVisible.ShouldBeFalse();
     }
 
     [Fact]
@@ -265,9 +265,9 @@ public void ExportSelection_ExporterFailure_ShowsErrorAndResetsBusyState()
 
         RunPinnedToTestThread(() => vm.ExportSelectionCommand.ExecuteAsync(null));
 
-        vm.ShowErrorOverlay.ShouldBeTrue();
-        vm.ErrorTitle.ShouldBe("Export Failed");
-        vm.ErrorDetails.ShouldContain("ffmpeg exploded");
+        vm.Error.IsVisible.ShouldBeTrue();
+        vm.Error.Title.ShouldBe("Export Failed");
+        vm.Error.Details.ShouldContain("ffmpeg exploded");
         vm.IsExporting.ShouldBeFalse();
     }
 
@@ -336,8 +336,8 @@ public async Task SaveEventClip_BuilderThrows_ShowsErrorInsteadOfCrashing()
 
         await vm.SaveEventClipCommand.ExecuteAsync(clip);
 
-        vm.ShowErrorOverlay.ShouldBeTrue();
-        vm.ErrorTitle.ShouldBe("Export Failed");
+        vm.Error.IsVisible.ShouldBeTrue();
+        vm.Error.Title.ShouldBe("Export Failed");
         exporter.Requests.ShouldBeEmpty();
         vm.IsExporting.ShouldBeFalse();
     }
diff --git a/SentryDeck.Tests/MainWindowViewModelTests.cs b/SentryDeck.Tests/MainWindowViewModelTests.cs
index 666ee68..4197da3 100644
--- a/SentryDeck.Tests/MainWindowViewModelTests.cs
+++ b/SentryDeck.Tests/MainWindowViewModelTests.cs
@@ -395,7 +395,7 @@ public void Error_ShowsStatusOverlay_AndReportsError()
     {
         var vm = CreateViewModel();
 
-        vm.ShowErrorOverlay = true;
+        vm.Error.IsVisible = true;
 
         vm.HasError.ShouldBeTrue();
         vm.ShowStatusOverlay.ShouldBeTrue();
@@ -541,18 +541,18 @@ public async Task UnhandledKeys_WithoutPlayer_ReturnFalse(Key key, ModifierKeys
     public void DismissError_ClearsErrorState()
     {
         var vm = CreateViewModel();
-        vm.ShowErrorOverlay = true;
-        vm.ShowFFmpegDownloadButton = true;
-        vm.CanDismissError = false;
-        vm.ErrorTitle = "Boom";
-        vm.ErrorDetails = "Something went wrong";
-
-        vm.DismissErrorCommand.Execute(null);
-
-        vm.ShowErrorOverlay.ShouldBeFalse();
-        vm.ShowFFmpegDownloadButton.ShouldBeFalse();
-        vm.CanDismissError.ShouldBeTrue();
-        vm.ErrorTitle.ShouldBeNull();
-        vm.ErrorDetails.ShouldBeNull();
+        vm.Error.IsVisible = true;
+        vm.Error.ShowFFmpegDownloadButton = true;
+        vm.Error.CanDismiss = false;
+        vm.Error.Title = "Boom";
+        vm.Error.Details = "Something went wrong";
+
+        vm.Error.DismissCommand.Execute(null);
+
+        vm.Error.IsVisible.ShouldBeFalse();
+        vm.Error.ShowFFmpegDownloadButton.ShouldBeFalse();
+        vm.Error.CanDismiss.ShouldBeTrue();
+        vm.Error.Title.ShouldBeNull();
+        vm.Error.Details.ShouldBeNull();
     }
 }
diff --git a/SentryDeck/MainWindow.xaml b/SentryDeck/MainWindow.xaml
index e59da54..3e203fc 100644
--- a/SentryDeck/MainWindow.xaml
+++ b/SentryDeck/MainWindow.xaml
@@ -1247,7 +1247,7 @@
                             </StackPanel>
 
                             <!--  Error / first-run empty state  -->
-                            <StackPanel Visibility="{Binding ShowErrorOverlay, Converter={local:BoolToVisibilityConverter}}">
+                            <StackPanel Visibility="{Binding Error.IsVisible, Converter={local:BoolToVisibilityConverter}}">
                                 <Border Width="64"
                                         Height="64"
                                         Margin="0,0,0,16"
@@ -1257,7 +1257,7 @@
                                         <Style TargetType="Border">
                                             <Setter Property="Background" Value="{DynamicResource SystemFillColorCriticalBackgroundBrush}" />
                                             <Style.Triggers>
-                                                <DataTrigger Binding="{Binding IsEmptyState}"
+                                                <DataTrigger Binding="{Binding Error.IsEmptyState}"
                                                              Value="True">
                                                     <Setter Property="Background" Value="{DynamicResource SubtleFillColorSecondaryBrush}" />
                                                 </DataTrigger>
@@ -1271,7 +1271,7 @@
                                                 <Setter Property="Text" Value="&#xE783;" />
                                                 <Setter Property="Foreground" Value="{DynamicResource SystemFillColorCriticalBrush}" />
                                                 <Style.Triggers>
-                                                    <DataTrigger Binding="{Binding IsEmptyState}"
+                                                    <DataTrigger Binding="{Binding Error.IsEmptyState}"
                                                                  Value="True">
                                                         <Setter Property="Text" Value="&#xE8B7;" />
                                                         <Setter Property="Foreground" Value="{DynamicResource TextFillColorSecondaryBrush}" />
@@ -1281,7 +1281,7 @@
                                         </TextBlock.Style>
                                     </TextBlock>
                                 </Border>
-                                <TextBlock Text="{Binding ErrorTitle}"
+                                <TextBlock Text="{Binding Error.Title}"
                                            Margin="0,0,0,8"
                                            HorizontalAlignment="Center"
                                            TextAlignment="Center">
@@ -1290,7 +1290,7 @@
                                                BasedOn="{StaticResource AppSubtitle}">
                                             <Setter Property="Foreground" Value="{DynamicResource SystemFillColorCriticalBrush}" />
                                             <Style.Triggers>
-                                                <DataTrigger Binding="{Binding IsEmptyState}"
+                                                <DataTrigger Binding="{Binding Error.IsEmptyState}"
                                                              Value="True">
                                                     <Setter Property="Foreground" Value="{DynamicResource TextFillColorPrimaryBrush}" />
                                                 </DataTrigger>
@@ -1298,7 +1298,7 @@
                                         </Style>
                                     </TextBlock.Style>
                                 </TextBlock>
-                                <TextBlock Text="{Binding ErrorDetails}"
+                                <TextBlock Text="{Binding Error.Details}"
                                            MaxWidth="380"
                                            HorizontalAlignment="Center"
                                            Foreground="{DynamicResource TextFillColorSecondaryBrush}"
@@ -1311,21 +1311,21 @@
                                         Padding="24,8"
                                         HorizontalAlignment="Center"
                                         Style="{StaticResource AccentButtonStyle}"
-                                        Visibility="{Binding IsEmptyState, Converter={local:BoolToVisibilityConverter}}" />
+                                        Visibility="{Binding Error.IsEmptyState, Converter={local:BoolToVisibilityConverter}}" />
                                 <Button Content="Download FFmpeg"
                                         Command="{Binding DownloadFFmpegCommand}"
                                         Margin="0,20,0,0"
                                         Padding="24,8"
                                         HorizontalAlignment="Center"
                                         Style="{StaticResource AccentButtonStyle}"
-                                        Visibility="{Binding ShowFFmpegDownloadButton, Converter={local:BoolToVisibilityConverter}}" />
+                                        Visibility="{Binding Error.ShowFFmpegDownloadButton, Converter={local:BoolToVisibilityConverter}}" />
                                 <Button Content="Dismiss"
-                                        Command="{Binding DismissErrorCommand}"
+                                        Command="{Binding Error.DismissCommand}"
                                         Margin="0,12,0,0"
                                         Padding="24,8"
                                         HorizontalAlignment="Center"
                                         Style="{StaticResource DefaultButtonStyle}"
-                                        Visibility="{Binding CanDismissError, Converter={local:BoolToVisibilityConverter}}" />
+                                        Visibility="{Binding Error.CanDismiss, Converter={local:BoolToVisibilityConverter}}" />
                             </StackPanel>
                         </StackPanel>
                     </Border>
diff --git a/SentryDeck/MainWindowViewModel.cs b/SentryDeck/MainWindowViewModel.cs
index eaf1637..347af70 100644
--- a/SentryDeck/MainWindowViewModel.cs
+++ b/SentryDeck/MainWindowViewModel.cs
@@ -96,6 +96,17 @@ public MainWindowViewModel(
         _filterDebounceTimer.Tick += OnFilterDebounceTick;
 
         SyncCameraViewSelection();
+
+        Error.PropertyChanged += (_, e) =>
+        {
+            if (e.PropertyName == nameof(ErrorOverlayViewModel.IsVisible))
+            {
+                OnPropertyChanged(nameof(ShowStatusOverlay));
+                OnPropertyChanged(nameof(ShowVideoHosts));
+                OnPropertyChanged(nameof(HasNoClipSelected));
+                OnPropertyChanged(nameof(HasError));
+            }
+        };
     }
 
     /// <summary>
@@ -103,6 +114,11 @@ public MainWindowViewModel(
     /// </summary>
     public event EventHandler SearchBoxFocusRequested;
 
+    /// <summary>
+    /// The notice over the video area; every feature reports errors through it.
+    /// </summary>
+    public ErrorOverlayViewModel Error { get; } = new();
+
     public bool ShowMainContent => !ShowAboutPage;
 
     public Version CurrentVersion => Assembly.GetExecutingAssembly().GetName().Version ?? new Version(0, 0, 0);
@@ -225,13 +241,13 @@ public string PositionText
 
     // The full-screen overlay only covers the no-video states (scanning with no clip, error, empty); as a WPF sibling it can't draw over the Flyleaf video surface anyway.
     // While a selected clip loads, the hosts stay visible and simply show black until the first frame decodes, with no loading screen flashing mid-playback.
-    public bool ShowStatusOverlay => (IsLoading && SelectedClip is null) || ShowErrorOverlay || HasNoClipSelected;
+    public bool ShowStatusOverlay => (IsLoading && SelectedClip is null) || Error.IsVisible || HasNoClipSelected;
 
-    public bool ShowVideoHosts => SelectedClip is not null && !ShowErrorOverlay;
+    public bool ShowVideoHosts => SelectedClip is not null && !Error.IsVisible;
 
-    public bool HasError => ShowErrorOverlay;
+    public bool HasError => Error.IsVisible;
 
-    public bool HasNoClipSelected => SelectedClip is null && !IsLoading && !ShowErrorOverlay;
+    public bool HasNoClipSelected => SelectedClip is null && !IsLoading && !Error.IsVisible;
 
     public bool IsGridViewSelected => SelectedCameraView == GridCameraView;
 
@@ -374,29 +390,6 @@ public string SelectionDurationText
     [ObservableProperty]
     private CamClip _nowPlayingClip;
 
-    [ObservableProperty]
-    private string _errorTitle;
-
-    [ObservableProperty]
-    private string _errorDetails;
-
-    [ObservableProperty]
-    [NotifyPropertyChangedFor(nameof(ShowStatusOverlay))]
-    [NotifyPropertyChangedFor(nameof(ShowVideoHosts))]
-    [NotifyPropertyChangedFor(nameof(HasNoClipSelected))]
-    [NotifyPropertyChangedFor(nameof(HasError))]
-    private bool _showErrorOverlay;
-
-    [ObservableProperty]
-    private bool _canDismissError = true;
-
-    // True when the overlay is a friendly first-run/empty prompt rather than a genuine error.
-    [ObservableProperty]
-    private bool _isEmptyState;
-
-    [ObservableProperty]
-    private bool _showFFmpegDownloadButton;
-
     [ObservableProperty]
     [NotifyPropertyChangedFor(nameof(ShowMainContent))]
     private bool _showAboutPage;
@@ -554,7 +547,7 @@ public void InitializePlayer()
 
     public async Task LoadClipsAsync(IEnumerable<string> roots, TimeSpan minimumLoadingDuration = default)
     {
-        ClearError();
+        Error.Clear();
         _allClips.Clear();
         SelectedClip = null;
         IsLoading = true;
@@ -574,7 +567,7 @@ public async Task LoadClipsAsync(IEnumerable<string> roots, TimeSpan minimumLoad
 
             if (!result.HadRoots)
             {
-                ShowError(
+                Error.Show(
                     "No dashcam footage yet",
                     "Point Sentry Deck at your TeslaCam folder to get started. Recorded USB drives are found automatically.",
                     canDismiss: true,
@@ -585,7 +578,7 @@ public async Task LoadClipsAsync(IEnumerable<string> roots, TimeSpan minimumLoad
                 _allClips.AddRange(result.Clips);
                 foreach (var error in result.Errors)
                 {
-                    ShowError(error.Title, error.Details);
+                    Error.Show(error.Title, error.Details);
                 }
             }
 
@@ -916,14 +909,14 @@ private async Task SaveEventClipAsync(CamClip clip)
         catch (Exception ex)
         {
             Log.Error(ex, "Failed to build media source for event clip. ClipName={ClipName}; ClipPath={ClipPath}", clip.Name, clip.FullPath);
-            ShowError("Export Failed", $"Could not export clip: {clip.Name}\n\nError: {ex.Message}");
+            Error.Show("Export Failed", $"Could not export clip: {clip.Name}\n\nError: {ex.Message}");
             return;
         }
 
         var eventTime = mediaSource.Duration > TimeSpan.Zero ? mediaSource.ToMediaTime(clip.Event.Timestamp) : null;
         if (eventTime is null)
         {
-            ShowError("Export Failed", "The event moment isn't within this clip's saved footage.");
+            Error.Show("Export Failed", "The event moment isn't within this clip's saved footage.");
             return;
         }
 
@@ -973,7 +966,7 @@ private async Task ExportAsync(CamClip clip, ClipMediaSource mediaSource, string
         catch (Exception ex)
         {
             Log.Error(ex, "Export failed. Clip={ClipName}; Camera={Camera}; Output={Output}", clip.Name, camera, outputPath);
-            ShowError("Export Failed", $"Could not export clip: {clip.Name}\n\nError: {ex.Message}");
+            Error.Show("Export Failed", $"Could not export clip: {clip.Name}\n\nError: {ex.Message}");
         }
         finally
         {
@@ -1057,7 +1050,7 @@ private async Task NextAsync()
     private async Task DownloadFFmpegAsync()
     {
         IsLoading = true;
-        ClearError();
+        Error.Clear();
 
         try
         {
@@ -1076,8 +1069,8 @@ private async Task DownloadFFmpegAsync()
         catch (Exception ex)
         {
             Log.Error(ex, "Failed to download FFmpeg");
-            ShowError("Download Failed", $"Failed to download FFmpeg: {ex.Message}");
-            ShowFFmpegDownloadButton = true;
+            Error.Show("Download Failed", $"Failed to download FFmpeg: {ex.Message}");
+            Error.ShowFFmpegDownloadButton = true;
         }
         finally
         {
@@ -1090,7 +1083,7 @@ private async Task PlaySelectedClipAsync(CamClip clip, CancellationToken cancell
         if (clip is null || _playerController is null)
             return;
 
-        ClearError();
+        Error.Clear();
         IsLoading = true;
         await _backgroundYield();
 
@@ -1138,7 +1131,7 @@ private async Task PlaySelectedClipAsync(CamClip clip, CancellationToken cancell
                 "Failed to play selected clip. ClipName={ClipName}; ClipPath={ClipPath}",
                 clip.Name,
                 clip.FullPath);
-            ShowError("Playback Failed", $"Could not play clip: {clip.Name}\n\nError: {ex.Message}");
+            Error.Show("Playback Failed", $"Could not play clip: {clip.Name}\n\nError: {ex.Message}");
         }
     }
 
@@ -1531,7 +1524,7 @@ private void HandlePlayerControllerPropertyChanged(string propertyName)
             case nameof(VideoPlayerController.ErrorMessage):
                 if (_playerController.ErrorMessage is not null)
                 {
-                    ShowError("Playback Error", _playerController.ErrorMessage);
+                    Error.Show("Playback Error", _playerController.ErrorMessage);
                 }
 
                 break;
@@ -1572,36 +1565,11 @@ private static string FormatVersion(Version version)
             : version.ToString(2);
     }
 
-    private void ShowError(string title, string details, bool canDismiss = true, bool isEmptyState = false)
-    {
-        ErrorTitle = title;
-        ErrorDetails = details;
-        CanDismissError = canDismiss;
-        IsEmptyState = isEmptyState;
-        ShowErrorOverlay = true;
-    }
-
-    private void ClearError()
-    {
-        ShowErrorOverlay = false;
-        ShowFFmpegDownloadButton = false;
-        CanDismissError = true;
-        IsEmptyState = false;
-        ErrorTitle = null;
-        ErrorDetails = null;
-    }
-
-    [RelayCommand]
-    private void DismissError()
-    {
-        ClearError();
-    }
-
     private void ShowFFmpegMissingError()
     {
         Log.Debug("Showing FFmpeg missing prompt");
-        ShowFFmpegDownloadButton = true;
-        ShowError("FFmpeg Required", "FFmpeg is required to play clips. This will download about 80MB.", canDismiss: false);
+        Error.ShowFFmpegDownloadButton = true;
+        Error.Show("FFmpeg Required", "FFmpeg is required to play clips. This will download about 80MB.", canDismiss: false);
     }
 
     [RelayCommand]
@@ -1669,7 +1637,7 @@ private void OpenClipFolder(CamClip clip)
 
         if (!Directory.Exists(clip.FullPath))
         {
-            ShowError("Clip Folder Not Found", $"Could not find folder:\n{clip.FullPath}");
+            Error.Show("Clip Folder Not Found", $"Could not find folder:\n{clip.FullPath}");
             return;
         }
 
@@ -1737,7 +1705,7 @@ private async Task DeleteClipAsync(CamClip clip)
         catch (Exception ex)
         {
             Log.Error(ex, "Failed to delete clip. ClipName={ClipName}; ClipPath={ClipPath}", clip.Name, clip.FullPath);
-            ShowError("Delete Failed", $"Could not delete clip: {clip.Name}\n\nError: {ex.Message}");
+            Error.Show("Delete Failed", $"Could not delete clip: {clip.Name}\n\nError: {ex.Message}");
             return;
         }
 
diff --git a/SentryDeck/ViewModels/ErrorOverlayViewModel.cs b/SentryDeck/ViewModels/ErrorOverlayViewModel.cs
new file mode 100644
index 0000000..1157f04
--- /dev/null
+++ b/SentryDeck/ViewModels/ErrorOverlayViewModel.cs
@@ -0,0 +1,52 @@
+using CommunityToolkit.Mvvm.ComponentModel;
+using CommunityToolkit.Mvvm.Input;
+
+namespace SentryDeck;
+
+/// <summary>
+/// The notice that covers the video area: a genuine error, or the friendly prompt shown when there is no footage yet.
+/// Every feature reports through the one instance the main window owns, so a newer notice replaces the one on screen.
+/// </summary>
+public sealed partial class ErrorOverlayViewModel : ObservableObject
+{
+    [ObservableProperty]
+    private string _title;
+
+    [ObservableProperty]
+    private string _details;
+
+    [ObservableProperty]
+    private bool _isVisible;
+
+    [ObservableProperty]
+    private bool _canDismiss = true;
+
+    // True when the notice is a friendly first-run/empty prompt rather than a genuine error.
+    [ObservableProperty]
+    private bool _isEmptyState;
+
+    [ObservableProperty]
+    private bool _showFFmpegDownloadButton;
+
+    public void Show(string title, string details, bool canDismiss = true, bool isEmptyState = false)
+    {
+        Title = title;
+        Details = details;
+        CanDismiss = canDismiss;
+        IsEmptyState = isEmptyState;
+        IsVisible = true;
+    }
+
+    public void Clear()
+    {
+        IsVisible = false;
+        ShowFFmpegDownloadButton = false;
+        CanDismiss = true;
+        IsEmptyState = false;
+        Title = null;
+        Details = null;
+    }
+
+    [RelayCommand]
+    private void Dismiss() => Clear();
+}

From a1ddee4e1927ddb3e57e991d3bb36fcbb1747260 Mon Sep 17 00:00:00 2001
From: Daniel Chalmers <daniel.chalmers@outlook.com>
Date: Thu, 24 Sep 2026 07:32:27 -0500
Subject: [PATCH 3/8] Move About page details into their own view-model

AboutViewModel owns what the About and help page shows: this build's version and runtime, and the result of the update check. Opening and closing the page stays on the main view-model, since the window and keyboard handling drive it.
---
 SentryDeck.Tests/MainWindowViewModelTests.cs | 26 +++----
 SentryDeck/MainWindow.xaml                   | 20 ++---
 SentryDeck/MainWindowViewModel.cs            | 78 ++-----------------
 SentryDeck/ViewModels/AboutViewModel.cs      | 82 ++++++++++++++++++++
 4 files changed, 111 insertions(+), 95 deletions(-)
 create mode 100644 SentryDeck/ViewModels/AboutViewModel.cs

diff --git a/SentryDeck.Tests/MainWindowViewModelTests.cs b/SentryDeck.Tests/MainWindowViewModelTests.cs
index 4197da3..2e4e8f2 100644
--- a/SentryDeck.Tests/MainWindowViewModelTests.cs
+++ b/SentryDeck.Tests/MainWindowViewModelTests.cs
@@ -465,12 +465,12 @@ public void UpdateBadge_DefaultsToUpToDate()
     {
         var vm = CreateViewModel();
 
-        vm.IsUpdateAvailable.ShouldBeFalse();
-        vm.HasUpdateBadge.ShouldBeFalse();
-        vm.UpdateStatusTitle.ShouldBe("You're up to date");
-        vm.UpdateStatusDetails.ShouldBe("No newer release was found.");
-        vm.LatestVersionText.ShouldBe("Unknown");
-        vm.LatestReleaseUrl.ShouldBe(UpdateService.ReleasesPageUrl);
+        vm.About.IsUpdateAvailable.ShouldBeFalse();
+        vm.About.HasUpdateBadge.ShouldBeFalse();
+        vm.About.UpdateStatusTitle.ShouldBe("You're up to date");
+        vm.About.UpdateStatusDetails.ShouldBe("No newer release was found.");
+        vm.About.LatestVersionText.ShouldBe("Unknown");
+        vm.About.LatestReleaseUrl.ShouldBe(UpdateService.ReleasesPageUrl);
     }
 
     [Fact]
@@ -478,14 +478,14 @@ public void UpdateBadge_ReflectsAvailableRelease()
     {
         var vm = CreateViewModel();
 
-        vm.LatestRelease = new UpdateRelease(new Version(1, 4, 2), "v1.4.2", "https://example.com/releases/1.4.2");
-        vm.IsUpdateAvailable = true;
+        vm.About.LatestRelease = new UpdateRelease(new Version(1, 4, 2), "v1.4.2", "https://example.com/releases/1.4.2");
+        vm.About.IsUpdateAvailable = true;
 
-        vm.HasUpdateBadge.ShouldBeTrue();
-        vm.UpdateStatusTitle.ShouldBe("Update available");
-        vm.LatestVersionText.ShouldBe("1.4.2");
-        vm.UpdateStatusDetails.ShouldBe("Version 1.4.2 is available.");
-        vm.LatestReleaseUrl.ShouldBe("https://example.com/releases/1.4.2");
+        vm.About.HasUpdateBadge.ShouldBeTrue();
+        vm.About.UpdateStatusTitle.ShouldBe("Update available");
+        vm.About.LatestVersionText.ShouldBe("1.4.2");
+        vm.About.UpdateStatusDetails.ShouldBe("Version 1.4.2 is available.");
+        vm.About.LatestReleaseUrl.ShouldBe("https://example.com/releases/1.4.2");
     }
 
     [Theory]
diff --git a/SentryDeck/MainWindow.xaml b/SentryDeck/MainWindow.xaml
index 3e203fc..dd386eb 100644
--- a/SentryDeck/MainWindow.xaml
+++ b/SentryDeck/MainWindow.xaml
@@ -949,7 +949,7 @@
                                     CornerRadius="4"
                                     IsHitTestVisible="False"
                                     ToolTip="Update available"
-                                    Visibility="{Binding HasUpdateBadge, Converter={local:BoolToVisibilityConverter}}" />
+                                    Visibility="{Binding About.HasUpdateBadge, Converter={local:BoolToVisibilityConverter}}" />
                         </Grid>
                     </Grid>
                 </Border>
@@ -1692,7 +1692,7 @@
                                     <TextBlock Margin="0,2,0,0"
                                                Foreground="{DynamicResource TextFillColorSecondaryBrush}">
                                         <Run Text="Version" />
-                                        <Run Text="{Binding FileVersion, Mode=OneWay}" />
+                                        <Run Text="{Binding About.FileVersion, Mode=OneWay}" />
                                     </TextBlock>
                                 </StackPanel>
                             </StackPanel>
@@ -1925,18 +1925,18 @@
                                             VerticalAlignment="Top"
                                             Background="{DynamicResource AccentFillColorDefaultBrush}"
                                             CornerRadius="6"
-                                            Visibility="{Binding HasUpdateBadge, Converter={local:BoolToVisibilityConverter}}" />
+                                            Visibility="{Binding About.HasUpdateBadge, Converter={local:BoolToVisibilityConverter}}" />
                                     <StackPanel Grid.Column="2">
-                                        <TextBlock Text="{Binding UpdateStatusTitle}"
+                                        <TextBlock Text="{Binding About.UpdateStatusTitle}"
                                                    FontWeight="SemiBold"
                                                    Foreground="{DynamicResource TextControlForeground}"
                                                    TextWrapping="Wrap" />
                                         <TextBlock Margin="0,4,0,0"
                                                    Foreground="{DynamicResource TextControlForeground}"
                                                    TextWrapping="Wrap">
-                                            <Run Text="{Binding UpdateStatusDetails, Mode=OneWay}" />
+                                            <Run Text="{Binding About.UpdateStatusDetails, Mode=OneWay}" />
                                             <Run Text=" " />
-                                            <Hyperlink NavigateUri="{Binding LatestReleaseUrl}"
+                                            <Hyperlink NavigateUri="{Binding About.LatestReleaseUrl}"
                                                        RequestNavigate="Hyperlink_RequestNavigate">
                                                 Learn more
                                             </Hyperlink>
@@ -1963,7 +1963,7 @@
                                                TextAlignment="Right" />
                                     <TextBlock Grid.Row="0"
                                                Grid.Column="2"
-                                               Text="{Binding FileVersion}"
+                                               Text="{Binding About.FileVersion}"
                                                Foreground="{DynamicResource TextControlForeground}" />
                                     <TextBlock Grid.Row="1"
                                                Grid.Column="0"
@@ -1973,7 +1973,7 @@
                                                TextAlignment="Right" />
                                     <TextBlock Grid.Row="1"
                                                Grid.Column="2"
-                                               Text="{Binding RuntimeDescription}"
+                                               Text="{Binding About.RuntimeDescription}"
                                                Foreground="{DynamicResource TextControlForeground}" />
                                     <TextBlock Grid.Row="2"
                                                Grid.Column="0"
@@ -1983,7 +1983,7 @@
                                                TextAlignment="Right" />
                                     <TextBlock Grid.Row="2"
                                                Grid.Column="2"
-                                               Text="{Binding OsDescription}"
+                                               Text="{Binding About.OsDescription}"
                                                Foreground="{DynamicResource TextControlForeground}" />
                                     <TextBlock Grid.Row="3"
                                                Grid.Column="0"
@@ -1993,7 +1993,7 @@
                                                TextAlignment="Right" />
                                     <TextBlock Grid.Row="3"
                                                Grid.Column="2"
-                                               Text="{Binding ExecutablePath}"
+                                               Text="{Binding About.ExecutablePath}"
                                                Foreground="{DynamicResource TextControlForeground}"
                                                TextWrapping="Wrap" />
                                 </Grid>
diff --git a/SentryDeck/MainWindowViewModel.cs b/SentryDeck/MainWindowViewModel.cs
index 347af70..56e0f76 100644
--- a/SentryDeck/MainWindowViewModel.cs
+++ b/SentryDeck/MainWindowViewModel.cs
@@ -2,8 +2,6 @@
 using System.Diagnostics;
 using System.Globalization;
 using System.IO;
-using System.Reflection;
-using System.Runtime.InteropServices;
 using System.Windows;
 using System.Windows.Input;
 using System.Windows.Threading;
@@ -38,7 +36,6 @@ public partial class MainWindowViewModel : ObservableObject
 
     private readonly List<CamClip> _allClips = [];
     private readonly FlyleafRuntime _flyleafRuntime = new();
-    private readonly UpdateService _updateService = new();
     private readonly Func<VideoPlayerController> _playerControllerFactory;
     private readonly Func<string, IReadOnlyList<CamClip>> _clipLoader;
     private readonly Func<Task> _backgroundYield;
@@ -119,33 +116,12 @@ public MainWindowViewModel(
     /// </summary>
     public ErrorOverlayViewModel Error { get; } = new();
 
-    public bool ShowMainContent => !ShowAboutPage;
-
-    public Version CurrentVersion => Assembly.GetExecutingAssembly().GetName().Version ?? new Version(0, 0, 0);
-
-    public string FileVersion => FormatVersion(CurrentVersion);
-
-    public string RuntimeDescription => $"{RuntimeInformation.FrameworkDescription} ({RuntimeInformation.ProcessArchitecture})";
-
-    public string OsDescription => RuntimeInformation.OSDescription;
-
-    public string ExecutablePath => Environment.ProcessPath;
-
-    public bool HasUpdateBadge => IsUpdateAvailable;
-
-    public string LatestVersionText => LatestRelease is null ? "Unknown" : FormatVersion(LatestRelease.Version);
-
-    public string LatestReleaseUrl => LatestRelease?.ReleaseUrl ?? UpdateService.ReleasesPageUrl;
-
-    public string ReleasesPageUrl => UpdateService.ReleasesPageUrl;
-
-    public string UpdateStatusTitle => IsUpdateAvailable
-        ? "Update available"
-        : "You're up to date";
+    /// <summary>
+    /// Version, environment, and update details for the About and help page.
+    /// </summary>
+    public AboutViewModel About { get; } = new();
 
-    public string UpdateStatusDetails => IsUpdateAvailable
-        ? $"Version {LatestVersionText} is available."
-        : "No newer release was found.";
+    public bool ShowMainContent => !ShowAboutPage;
 
     /// <summary>
     /// Ladder the speed stepper walks: fine increments around 1x, doubling above.
@@ -481,18 +457,6 @@ private void SyncCameraViewSelection()
         }
     }
 
-    [ObservableProperty]
-    [NotifyPropertyChangedFor(nameof(HasUpdateBadge))]
-    [NotifyPropertyChangedFor(nameof(UpdateStatusTitle))]
-    [NotifyPropertyChangedFor(nameof(UpdateStatusDetails))]
-    private bool _isUpdateAvailable;
-
-    [ObservableProperty]
-    [NotifyPropertyChangedFor(nameof(LatestVersionText))]
-    [NotifyPropertyChangedFor(nameof(LatestReleaseUrl))]
-    [NotifyPropertyChangedFor(nameof(UpdateStatusDetails))]
-    private UpdateRelease _latestRelease;
-
     public async Task InitializeAsync()
     {
         if (_isInitialized)
@@ -504,7 +468,7 @@ public async Task InitializeAsync()
 #if DEBUG
         Log.Debug("Skipping update check in debug build");
 #else
-        _ = UpdateLatestReleaseAsync();
+        _ = About.CheckForUpdatesAsync();
 #endif
 
         if (_flyleafRuntime.TryStart())
@@ -1548,23 +1512,6 @@ internal static string FormatTimeSpan(TimeSpan ts)
             : ts.ToString(@"m\:ss");
     }
 
-    private static string FormatVersion(Version version)
-    {
-        if (version is null)
-        {
-            return "Unknown";
-        }
-
-        if (version.Revision >= 0)
-        {
-            return version.ToString(4);
-        }
-
-        return version.Build >= 0
-            ? version.ToString(3)
-            : version.ToString(2);
-    }
-
     private void ShowFFmpegMissingError()
     {
         Log.Debug("Showing FFmpeg missing prompt");
@@ -1609,19 +1556,6 @@ internal string CameraIdToView(int cameraId)
         return IsAvailableView(camera) ? camera : CameraNames.Front;
     }
 
-    private async Task UpdateLatestReleaseAsync()
-    {
-        var result = await _updateService.CheckForUpdateAsync(CurrentVersion);
-        LatestRelease = result.LatestRelease;
-        IsUpdateAvailable = result.IsUpdateAvailable;
-
-        Log.Information(
-            "Checked for updates. CurrentVersion={CurrentVersion}; LatestVersion={LatestVersion}; IsUpdateAvailable={IsUpdateAvailable}",
-            FormatVersion(CurrentVersion),
-            LatestVersionText,
-            IsUpdateAvailable);
-    }
-
     private static bool CanUseClip(CamClip clip)
     {
         return clip is not null;
diff --git a/SentryDeck/ViewModels/AboutViewModel.cs b/SentryDeck/ViewModels/AboutViewModel.cs
new file mode 100644
index 0000000..336d471
--- /dev/null
+++ b/SentryDeck/ViewModels/AboutViewModel.cs
@@ -0,0 +1,82 @@
+using System.Reflection;
+using System.Runtime.InteropServices;
+using CommunityToolkit.Mvvm.ComponentModel;
+using Serilog;
+
+namespace SentryDeck;
+
+/// <summary>
+/// What the About and help page shows: this build's version and environment, and whether a newer release is out.
+/// </summary>
+public sealed partial class AboutViewModel : ObservableObject
+{
+    private readonly UpdateService _updateService = new();
+
+    public Version CurrentVersion => Assembly.GetExecutingAssembly().GetName().Version ?? new Version(0, 0, 0);
+
+    public string FileVersion => FormatVersion(CurrentVersion);
+
+    public string RuntimeDescription => $"{RuntimeInformation.FrameworkDescription} ({RuntimeInformation.ProcessArchitecture})";
+
+    public string OsDescription => RuntimeInformation.OSDescription;
+
+    public string ExecutablePath => Environment.ProcessPath;
+
+    public bool HasUpdateBadge => IsUpdateAvailable;
+
+    public string LatestVersionText => LatestRelease is null ? "Unknown" : FormatVersion(LatestRelease.Version);
+
+    public string LatestReleaseUrl => LatestRelease?.ReleaseUrl ?? UpdateService.ReleasesPageUrl;
+
+    public string ReleasesPageUrl => UpdateService.ReleasesPageUrl;
+
+    public string UpdateStatusTitle => IsUpdateAvailable
+        ? "Update available"
+        : "You're up to date";
+
+    public string UpdateStatusDetails => IsUpdateAvailable
+        ? $"Version {LatestVersionText} is available."
+        : "No newer release was found.";
+
+    [ObservableProperty]
+    [NotifyPropertyChangedFor(nameof(HasUpdateBadge))]
+    [NotifyPropertyChangedFor(nameof(UpdateStatusTitle))]
+    [NotifyPropertyChangedFor(nameof(UpdateStatusDetails))]
+    private bool _isUpdateAvailable;
+
+    [ObservableProperty]
+    [NotifyPropertyChangedFor(nameof(LatestVersionText))]
+    [NotifyPropertyChangedFor(nameof(LatestReleaseUrl))]
+    [NotifyPropertyChangedFor(nameof(UpdateStatusDetails))]
+    private UpdateRelease _latestRelease;
+
+    public async Task CheckForUpdatesAsync()
+    {
+        var result = await _updateService.CheckForUpdateAsync(CurrentVersion);
+        LatestRelease = result.LatestRelease;
+        IsUpdateAvailable = result.IsUpdateAvailable;
+
+        Log.Information(
+            "Checked for updates. CurrentVersion={CurrentVersion}; LatestVersion={LatestVersion}; IsUpdateAvailable={IsUpdateAvailable}",
+            FormatVersion(CurrentVersion),
+            LatestVersionText,
+            IsUpdateAvailable);
+    }
+
+    private static string FormatVersion(Version version)
+    {
+        if (version is null)
+        {
+            return "Unknown";
+        }
+
+        if (version.Revision >= 0)
+        {
+            return version.ToString(4);
+        }
+
+        return version.Build >= 0
+            ? version.ToString(3)
+            : version.ToString(2);
+    }
+}

From 2d56eda51b07b1d61ae4711c93fee64205d88ffc Mon Sep 17 00:00:00 2001
From: Daniel Chalmers <daniel.chalmers@outlook.com>
Date: Thu, 24 Sep 2026 07:35:51 -0500
Subject: [PATCH 4/8] Move camera view selection into its own view-model

CameraViewsViewModel owns which camera is enlarged (or the grid), the selector strip built from the cameras a clip actually recorded, the event-camera mapping, and which camera an export of the current view uses. The window now listens to it directly to re-parent its Flyleaf hosts, and the main view-model only tells it when the selected clip changes.
---
 .../MainWindowViewModelTests.Keyboard.cs      |   2 +-
 .../MainWindowViewModelTests.Playback.cs      |   2 +-
 .../MainWindowViewModelTests.Trimming.cs      |   2 +-
 SentryDeck.Tests/MainWindowViewModelTests.cs  |  92 +++++------
 SentryDeck/CameraViewOption.cs                |   2 +-
 SentryDeck/MainWindow.xaml                    |  10 +-
 SentryDeck/MainWindow.xaml.cs                 |  16 +-
 SentryDeck/MainWindowViewModel.cs             | 141 ++---------------
 SentryDeck/ViewModels/CameraViewsViewModel.cs | 147 ++++++++++++++++++
 9 files changed, 221 insertions(+), 193 deletions(-)
 create mode 100644 SentryDeck/ViewModels/CameraViewsViewModel.cs

diff --git a/SentryDeck.Tests/MainWindowViewModelTests.Keyboard.cs b/SentryDeck.Tests/MainWindowViewModelTests.Keyboard.cs
index 482a5ec..2d6fea3 100644
--- a/SentryDeck.Tests/MainWindowViewModelTests.Keyboard.cs
+++ b/SentryDeck.Tests/MainWindowViewModelTests.Keyboard.cs
@@ -160,7 +160,7 @@ public async Task SupersededSelection_DoesNotClearTheNewerLoadsLoadingState()
 
         // The winner's load resumes and auto-focuses the rear camera.
         // The superseded load is dropped on its way out, and the loading state it finds is no longer its own to clear -- doing so would strand the newer clip's open with no progress indication at all.
-        await Wait.UntilAsync(() => vm.SelectedCameraView == CameraNames.Back);
+        await Wait.UntilAsync(() => vm.Cameras.SelectedCameraView == CameraNames.Back);
         vm.IsLoading.ShouldBeTrue();
         vm.NowPlayingClip.ShouldBe(winner);
         vm.SelectedClip.ShouldBe(winner);
diff --git a/SentryDeck.Tests/MainWindowViewModelTests.Playback.cs b/SentryDeck.Tests/MainWindowViewModelTests.Playback.cs
index 613c337..5f7d5fb 100644
--- a/SentryDeck.Tests/MainWindowViewModelTests.Playback.cs
+++ b/SentryDeck.Tests/MainWindowViewModelTests.Playback.cs
@@ -199,7 +199,7 @@ public void SelectingAnEventClip_AutoFocusesTheTriggeringCamera()
         vm.SelectedClip = ClipWithCamerasAndEventCamera(eventCamera: 7, SixCameras);
 
         // Opening an incident on the angle that triggered it is the whole point of the metadata.
-        vm.SelectedCameraView.ShouldBe(CameraNames.Back);
+        vm.Cameras.SelectedCameraView.ShouldBe(CameraNames.Back);
     }
 
     [Fact]
diff --git a/SentryDeck.Tests/MainWindowViewModelTests.Trimming.cs b/SentryDeck.Tests/MainWindowViewModelTests.Trimming.cs
index b720c43..6a10cf1 100644
--- a/SentryDeck.Tests/MainWindowViewModelTests.Trimming.cs
+++ b/SentryDeck.Tests/MainWindowViewModelTests.Trimming.cs
@@ -216,7 +216,7 @@ public void ExportSelection_SendsMediaTimeRangeAndActiveCameraToTheExporter()
         var exporter = new FakeClipExporter();
         var (vm, _, _) = CreateViewModelWithOpenedClip(clipFiles.Clip, exporter, _ => @"C:\out\clip.mp4");
 
-        vm.SelectCameraViewCommand.Execute(CameraNames.Back);
+        vm.Cameras.SelectCameraViewCommand.Execute(CameraNames.Back);
         vm.SeekPosition = 0.25;
         vm.MarkSelectionStartCommand.Execute(null);
         vm.SeekPosition = 0.75;
diff --git a/SentryDeck.Tests/MainWindowViewModelTests.cs b/SentryDeck.Tests/MainWindowViewModelTests.cs
index 2e4e8f2..a00fbf9 100644
--- a/SentryDeck.Tests/MainWindowViewModelTests.cs
+++ b/SentryDeck.Tests/MainWindowViewModelTests.cs
@@ -162,10 +162,10 @@ public void NewViewModel_DefaultsToFrontCamera_AndEmptyOverlay()
     {
         var vm = CreateViewModel();
 
-        vm.SelectedCameraView.ShouldBe(CameraNames.Front);
-        vm.IsGridViewSelected.ShouldBeFalse();
-        vm.IsSingleCameraViewSelected.ShouldBeTrue();
-        vm.CameraViewOptions.Single(option => option.ViewId == CameraNames.Front).IsSelected.ShouldBeTrue();
+        vm.Cameras.SelectedCameraView.ShouldBe(CameraNames.Front);
+        vm.Cameras.IsGridViewSelected.ShouldBeFalse();
+        vm.Cameras.IsSingleCameraViewSelected.ShouldBeTrue();
+        vm.Cameras.CameraViewOptions.Single(option => option.ViewId == CameraNames.Front).IsSelected.ShouldBeTrue();
         vm.ShowMainContent.ShouldBeTrue();
         vm.ShowAboutPage.ShouldBeFalse();
 
@@ -187,13 +187,13 @@ public void SelectCameraView_SetsSelectedViewAndLabel(string cameraView, string
     {
         var vm = CreateViewModel();
 
-        vm.SelectCameraViewCommand.Execute(cameraView);
+        vm.Cameras.SelectCameraViewCommand.Execute(cameraView);
 
         var expectedView = expectedLabel == "Front"
             ? CameraNames.Front
             : cameraView;
-        vm.SelectedCameraView.ShouldBe(expectedView);
-        vm.ActiveCameraLabel.ShouldBe(expectedLabel);
+        vm.Cameras.SelectedCameraView.ShouldBe(expectedView);
+        vm.Cameras.ActiveCameraLabel.ShouldBe(expectedLabel);
     }
 
     [Fact]
@@ -201,15 +201,15 @@ public void NewViewModel_OffersGridPlusClassicFourCameras()
     {
         var vm = CreateViewModel();
 
-        vm.CameraViewOptions.Select(option => option.ViewId).ShouldBe(
+        vm.Cameras.CameraViewOptions.Select(option => option.ViewId).ShouldBe(
             [
-                MainWindowViewModel.GridCameraView,
+                CameraViewsViewModel.GridCameraView,
                 CameraNames.Front,
                 CameraNames.Back,
                 CameraNames.LeftRepeater,
                 CameraNames.RightRepeater,
             ]);
-        vm.CameraViewOptions.Select(option => option.ShortcutNumber).ShouldBe([1, 2, 3, 4, 5]);
+        vm.Cameras.CameraViewOptions.Select(option => option.ShortcutNumber).ShouldBe([1, 2, 3, 4, 5]);
     }
 
     [Fact]
@@ -217,10 +217,10 @@ public void SelectCameraView_Grid_SetsGridFlags()
     {
         var vm = CreateViewModel();
 
-        vm.SelectCameraViewCommand.Execute("grid");
+        vm.Cameras.SelectCameraViewCommand.Execute("grid");
 
-        vm.IsGridViewSelected.ShouldBeTrue();
-        vm.IsSingleCameraViewSelected.ShouldBeFalse();
+        vm.Cameras.IsGridViewSelected.ShouldBeTrue();
+        vm.Cameras.IsSingleCameraViewSelected.ShouldBeFalse();
     }
 
     [Fact]
@@ -228,12 +228,12 @@ public void SelectCameraView_Rear_SetsSingleViewFlags_AndMarksItsTile()
     {
         var vm = CreateViewModel();
 
-        vm.SelectCameraViewCommand.Execute(CameraNames.Back);
+        vm.Cameras.SelectCameraViewCommand.Execute(CameraNames.Back);
 
-        vm.SelectedCameraView.ShouldBe(CameraNames.Back);
-        vm.IsGridViewSelected.ShouldBeFalse();
-        vm.IsSingleCameraViewSelected.ShouldBeTrue();
-        vm.CameraViewOptions.Single(option => option.IsSelected).ViewId.ShouldBe(CameraNames.Back);
+        vm.Cameras.SelectedCameraView.ShouldBe(CameraNames.Back);
+        vm.Cameras.IsGridViewSelected.ShouldBeFalse();
+        vm.Cameras.IsSingleCameraViewSelected.ShouldBeTrue();
+        vm.Cameras.CameraViewOptions.Single(option => option.IsSelected).ViewId.ShouldBe(CameraNames.Back);
     }
 
     [Fact]
@@ -243,9 +243,9 @@ public void SixCameraClip_OffersPillarTiles_InCanonicalOrder()
 
         vm.SelectedClip = ClipWithCameras(SixCameras);
 
-        vm.CameraViewOptions.Select(option => option.ViewId).ShouldBe(
+        vm.Cameras.CameraViewOptions.Select(option => option.ViewId).ShouldBe(
             [
-                MainWindowViewModel.GridCameraView,
+                CameraViewsViewModel.GridCameraView,
                 CameraNames.Front,
                 CameraNames.Back,
                 CameraNames.LeftRepeater,
@@ -253,12 +253,12 @@ public void SixCameraClip_OffersPillarTiles_InCanonicalOrder()
                 CameraNames.LeftPillar,
                 CameraNames.RightPillar,
             ]);
-        vm.CameraViewOptions.Select(option => option.ShortcutNumber).ShouldBe([1, 2, 3, 4, 5, 6, 7]);
-        vm.CameraViewOptions.Last().Label.ShouldBe("Right Pillar");
+        vm.Cameras.CameraViewOptions.Select(option => option.ShortcutNumber).ShouldBe([1, 2, 3, 4, 5, 6, 7]);
+        vm.Cameras.CameraViewOptions.Last().Label.ShouldBe("Right Pillar");
 
-        vm.SelectCameraViewCommand.Execute(CameraNames.LeftPillar);
-        vm.SelectedCameraView.ShouldBe(CameraNames.LeftPillar);
-        vm.ActiveCameraLabel.ShouldBe("Left Pillar");
+        vm.Cameras.SelectCameraViewCommand.Execute(CameraNames.LeftPillar);
+        vm.Cameras.SelectedCameraView.ShouldBe(CameraNames.LeftPillar);
+        vm.Cameras.ActiveCameraLabel.ShouldBe("Left Pillar");
     }
 
     [Fact]
@@ -268,11 +268,11 @@ public void FourCameraClip_DoesNotOfferPillarTiles_AndPillarSelectionFallsBackTo
 
         vm.SelectedClip = ClipWithCameras(CameraNames.Front, CameraNames.Back, CameraNames.LeftRepeater, CameraNames.RightRepeater);
 
-        vm.CameraViewOptions.Count.ShouldBe(5);
-        vm.CameraViewOptions.ShouldAllBe(option => option.ViewId != CameraNames.LeftPillar);
+        vm.Cameras.CameraViewOptions.Count.ShouldBe(5);
+        vm.Cameras.CameraViewOptions.ShouldAllBe(option => option.ViewId != CameraNames.LeftPillar);
 
-        vm.SelectCameraViewCommand.Execute(CameraNames.LeftPillar);
-        vm.SelectedCameraView.ShouldBe(CameraNames.Front);
+        vm.Cameras.SelectCameraViewCommand.Execute(CameraNames.LeftPillar);
+        vm.Cameras.SelectedCameraView.ShouldBe(CameraNames.Front);
     }
 
     [Fact]
@@ -280,11 +280,11 @@ public void SwitchingToClipWithoutTheWatchedCamera_FallsBackToFront()
     {
         var vm = CreateViewModel();
         vm.SelectedClip = ClipWithCameras(SixCameras);
-        vm.SelectCameraViewCommand.Execute(CameraNames.RightPillar);
+        vm.Cameras.SelectCameraViewCommand.Execute(CameraNames.RightPillar);
 
         vm.SelectedClip = ClipWithCameras(CameraNames.Front, CameraNames.Back, CameraNames.LeftRepeater, CameraNames.RightRepeater);
 
-        vm.SelectedCameraView.ShouldBe(CameraNames.Front);
+        vm.Cameras.SelectedCameraView.ShouldBe(CameraNames.Front);
     }
 
     [Fact]
@@ -292,12 +292,12 @@ public void SwitchingClips_KeepsTheWatchedCamera_WhenTheNewClipHasIt()
     {
         var vm = CreateViewModel();
         vm.SelectedClip = ClipWithCameras(SixCameras);
-        vm.SelectCameraViewCommand.Execute(CameraNames.LeftPillar);
+        vm.Cameras.SelectCameraViewCommand.Execute(CameraNames.LeftPillar);
 
         vm.SelectedClip = ClipWithCameras(SixCameras);
 
-        vm.SelectedCameraView.ShouldBe(CameraNames.LeftPillar);
-        vm.CameraViewOptions.Single(option => option.IsSelected).ViewId.ShouldBe(CameraNames.LeftPillar);
+        vm.Cameras.SelectedCameraView.ShouldBe(CameraNames.LeftPillar);
+        vm.Cameras.CameraViewOptions.Single(option => option.IsSelected).ViewId.ShouldBe(CameraNames.LeftPillar);
     }
 
     [Theory]
@@ -314,7 +314,7 @@ public void CameraIdToView_MapsDocumentedEventCameraIds(int cameraId, string exp
         var vm = CreateViewModel();
         vm.SelectedClip = ClipWithCameras(SixCameras);
 
-        vm.CameraIdToView(cameraId).ShouldBe(expectedView);
+        vm.Cameras.CameraIdToView(cameraId).ShouldBe(expectedView);
     }
 
     [Fact]
@@ -323,8 +323,8 @@ public void CameraIdToView_FallsBackToFront_WhenTheClipLacksThatCamera()
         var vm = CreateViewModel();
         vm.SelectedClip = ClipWithCameras(CameraNames.Front, CameraNames.Back, CameraNames.LeftRepeater, CameraNames.RightRepeater);
 
-        vm.CameraIdToView(5).ShouldBe(CameraNames.Front);
-        vm.CameraIdToView(7).ShouldBe(CameraNames.Back);
+        vm.Cameras.CameraIdToView(5).ShouldBe(CameraNames.Front);
+        vm.Cameras.CameraIdToView(7).ShouldBe(CameraNames.Back);
     }
 
     [Fact]
@@ -334,13 +334,13 @@ public async Task NumberKeys_SelectTilesByStripPosition_IncludingPillars()
         vm.SelectedClip = ClipWithCameras(SixCameras);
 
         (await vm.HandleKeyDownAsync(Key.D6, ModifierKeys.None)).ShouldBeTrue();
-        vm.SelectedCameraView.ShouldBe(CameraNames.LeftPillar);
+        vm.Cameras.SelectedCameraView.ShouldBe(CameraNames.LeftPillar);
 
         (await vm.HandleKeyDownAsync(Key.NumPad7, ModifierKeys.None)).ShouldBeTrue();
-        vm.SelectedCameraView.ShouldBe(CameraNames.RightPillar);
+        vm.Cameras.SelectedCameraView.ShouldBe(CameraNames.RightPillar);
 
         (await vm.HandleKeyDownAsync(Key.D1, ModifierKeys.None)).ShouldBeTrue();
-        vm.SelectedCameraView.ShouldBe(MainWindowViewModel.GridCameraView);
+        vm.Cameras.SelectedCameraView.ShouldBe(CameraViewsViewModel.GridCameraView);
     }
 
     [Fact]
@@ -349,7 +349,7 @@ public async Task NumberKeys_BeyondTheStrip_AreNotHandled()
         var vm = CreateViewModel(); // classic strip: 5 tiles, so 6 has no target
 
         (await vm.HandleKeyDownAsync(Key.D6, ModifierKeys.None)).ShouldBeFalse();
-        vm.SelectedCameraView.ShouldBe(CameraNames.Front);
+        vm.Cameras.SelectedCameraView.ShouldBe(CameraNames.Front);
     }
 
     [Fact]
@@ -358,11 +358,11 @@ public void SelectCameraView_RaisesPropertyChangedForSelectedCameraView()
         // The view re-parents the Flyleaf hosts when SelectedCameraView changes, so this notification is part of the view/view-model contract.
         var vm = CreateViewModel();
         var changed = new List<string>();
-        vm.PropertyChanged += (_, e) => changed.Add(e.PropertyName);
+        vm.Cameras.PropertyChanged += (_, e) => changed.Add(e.PropertyName);
 
-        vm.SelectCameraViewCommand.Execute("grid");
+        vm.Cameras.SelectCameraViewCommand.Execute("grid");
 
-        changed.ShouldContain(nameof(MainWindowViewModel.SelectedCameraView));
+        changed.ShouldContain(nameof(CameraViewsViewModel.SelectedCameraView));
     }
 
     [Fact]
@@ -514,12 +514,12 @@ public async Task AboutPage_SwallowsPlayerShortcuts(Key key, ModifierKeys modifi
     {
         var vm = CreateViewModel();
         vm.ShowAboutPage = true;
-        var cameraViewBefore = vm.SelectedCameraView;
+        var cameraViewBefore = vm.Cameras.SelectedCameraView;
 
         var handled = await vm.HandleKeyDownAsync(key, modifiers);
 
         handled.ShouldBeFalse();
-        vm.SelectedCameraView.ShouldBe(cameraViewBefore); // no camera switch behind the About page
+        vm.Cameras.SelectedCameraView.ShouldBe(cameraViewBefore); // no camera switch behind the About page
         vm.IsTrimming.ShouldBeFalse();
         vm.ShowAboutPage.ShouldBeTrue(); // the page stays open
     }
diff --git a/SentryDeck/CameraViewOption.cs b/SentryDeck/CameraViewOption.cs
index 6fab8e9..0e06087 100644
--- a/SentryDeck/CameraViewOption.cs
+++ b/SentryDeck/CameraViewOption.cs
@@ -16,7 +16,7 @@ public CameraViewOption(string viewId, string label, int shortcutNumber, bool is
     }
 
     /// <summary>
-    /// <see cref="MainWindowViewModel.GridCameraView"/> or a canonical <see cref="CameraNames"/> name.
+    /// <see cref="CameraViewsViewModel.GridCameraView"/> or a canonical <see cref="CameraNames"/> name.
     /// </summary>
     public string ViewId { get; }
 
diff --git a/SentryDeck/MainWindow.xaml b/SentryDeck/MainWindow.xaml
index dd386eb..6c6bc21 100644
--- a/SentryDeck/MainWindow.xaml
+++ b/SentryDeck/MainWindow.xaml
@@ -1010,7 +1010,7 @@
                                 CornerRadius="6"
                                 Focusable="True">
                             <Grid>
-                                <Grid Visibility="{Binding IsGridViewSelected, Converter={local:BoolToVisibilityConverter}}">
+                                <Grid Visibility="{Binding Cameras.IsGridViewSelected, Converter={local:BoolToVisibilityConverter}}">
                                     <Grid.RowDefinitions>
                                         <RowDefinition Height="*" />
                                         <RowDefinition Height="*" />
@@ -1101,7 +1101,7 @@
                                     </Border>
                                 </Grid>
 
-                                <Grid Visibility="{Binding IsSingleCameraViewSelected, Converter={local:BoolToVisibilityConverter}}">
+                                <Grid Visibility="{Binding Cameras.IsSingleCameraViewSelected, Converter={local:BoolToVisibilityConverter}}">
                                     <ContentControl x:Name="PrimaryCameraHostSlot" />
                                     <Border Margin="14"
                                             Padding="10,4"
@@ -1109,7 +1109,7 @@
                                             VerticalAlignment="Top"
                                             Background="#A0000000"
                                             CornerRadius="4">
-                                        <TextBlock Text="{Binding ActiveCameraLabel}"
+                                        <TextBlock Text="{Binding Cameras.ActiveCameraLabel}"
                                                    FontSize="13"
                                                    FontWeight="SemiBold"
                                                    Foreground="White" />
@@ -1127,7 +1127,7 @@
                                 CornerRadius="8">
                             <!--  One tile per view the current clip offers: the grid plus each recorded camera (four on HW3, six on HW4/AI4).
                                   Camera tiles carry a preview slot that registers itself with the code-behind (CameraTileSlot_Loaded), which re-parents each camera's Flyleaf host into it.  -->
-                            <ItemsControl ItemsSource="{Binding CameraViewOptions}">
+                            <ItemsControl ItemsSource="{Binding Cameras.CameraViewOptions}">
                                 <ItemsControl.ItemsPanel>
                                     <ItemsPanelTemplate>
                                         <UniformGrid Rows="1" />
@@ -1135,7 +1135,7 @@
                                 </ItemsControl.ItemsPanel>
                                 <ItemsControl.ItemTemplate>
                                     <DataTemplate DataType="{x:Type local:CameraViewOption}">
-                                        <RadioButton Command="{Binding DataContext.SelectCameraViewCommand, RelativeSource={RelativeSource AncestorType=ItemsControl}}"
+                                        <RadioButton Command="{Binding DataContext.Cameras.SelectCameraViewCommand, RelativeSource={RelativeSource AncestorType=ItemsControl}}"
                                                      CommandParameter="{Binding ViewId}"
                                                      AutomationProperties.Name="{Binding AutomationName}"
                                                      GroupName="CameraViewMode"
diff --git a/SentryDeck/MainWindow.xaml.cs b/SentryDeck/MainWindow.xaml.cs
index 6c8efb5..182ea4a 100644
--- a/SentryDeck/MainWindow.xaml.cs
+++ b/SentryDeck/MainWindow.xaml.cs
@@ -44,7 +44,7 @@ public MainWindow()
         _viewModel = new MainWindowViewModel(
             () => VideoPlayerController.Create([.. _cameraHosts.Select(pair => (pair.Key, pair.Value))]));
         _viewModel.SearchBoxFocusRequested += OnSearchBoxFocusRequested;
-        _viewModel.PropertyChanged += ViewModelOnPropertyChanged;
+        _viewModel.Cameras.PropertyChanged += CamerasOnPropertyChanged;
 
         DataContext = _viewModel;
 
@@ -177,11 +177,11 @@ private void SeekSlider_ValueChanged(object sender, RoutedPropertyChangedEventAr
         _viewModel.OnSeekSliderValueChanged();
     }
 
-    private void ViewModelOnPropertyChanged(object sender, PropertyChangedEventArgs e)
+    private void CamerasOnPropertyChanged(object sender, PropertyChangedEventArgs e)
     {
         // Re-parent the hosts when the enlarged view changes, and when a new clip swaps in a different camera set (the freshly generated tiles also self-register via CameraTileSlot_Loaded, which covers containers that don't exist yet at this moment).
-        if (e.PropertyName is nameof(MainWindowViewModel.SelectedCameraView)
-            or nameof(MainWindowViewModel.CameraViewOptions))
+        if (e.PropertyName is nameof(CameraViewsViewModel.SelectedCameraView)
+            or nameof(CameraViewsViewModel.CameraViewOptions))
         {
             UpdateCameraHostLayout();
         }
@@ -204,7 +204,7 @@ private void HookCameraClick(FlyleafHost host, string cameraView)
                     MouseLeftButtonUpEvent,
                     new MouseButtonEventHandler((_, e) =>
                     {
-                        _viewModel.SelectCameraViewCommand.Execute(cameraView);
+                        _viewModel.Cameras.SelectCameraViewCommand.Execute(cameraView);
 
                         // The click moved Win32 focus to the native Flyleaf surface, which never routes keys back into WPF, so every keyboard shortcut would go dead.
                         // Pull it back onto the video container, a neutral focusable element that consumes no shortcut keys (see its remarks in the XAML).
@@ -235,7 +235,7 @@ private void UpdateCameraHostLayout()
 
         var placed = new HashSet<FlyleafHost>();
 
-        foreach (var (host, slot) in GetCameraHostLayout(_viewModel.SelectedCameraView))
+        foreach (var (host, slot) in GetCameraHostLayout(_viewModel.Cameras.SelectedCameraView))
         {
             MoveHostToSlot(host, slot);
             placed.Add(host);
@@ -257,7 +257,7 @@ private void UpdateCameraHostLayout()
 
     private IEnumerable<(FlyleafHost Host, ContentControl Slot)> GetCameraHostLayout(string view)
     {
-        if (view == MainWindowViewModel.GridCameraView)
+        if (view == CameraViewsViewModel.GridCameraView)
         {
             // The grid stays the classic four-camera 2x2 for now; pillar cameras are reachable through their single-camera views.
             yield return (FrontFlyleafHost, GridFrontHostSlot);
@@ -275,7 +275,7 @@ private void UpdateCameraHostLayout()
         yield return (primaryHost, PrimaryCameraHostSlot);
 
         // Every other camera of this clip previews inside its own selector tile; the enlarged camera's tile stays empty behind its "this is the main view" icon.
-        foreach (var option in _viewModel.CameraViewOptions)
+        foreach (var option in _viewModel.Cameras.CameraViewOptions)
         {
             if (option.IsCamera
                 && option.ViewId != view
diff --git a/SentryDeck/MainWindowViewModel.cs b/SentryDeck/MainWindowViewModel.cs
index 56e0f76..8717a57 100644
--- a/SentryDeck/MainWindowViewModel.cs
+++ b/SentryDeck/MainWindowViewModel.cs
@@ -15,25 +15,10 @@ namespace SentryDeck;
 
 /// <summary>
 /// View-model for the main window: clip browsing, playback orchestration, update checks, FFmpeg prompts, and shell actions.
-/// Holds no references to WPF controls; the view supplies the playback controller (via <see cref="MainWindowViewModel(Func{VideoPlayerController})"/>) and reacts to <see cref="SearchBoxFocusRequested"/> and <see cref="SelectedCameraView"/> changes.
+/// Holds no references to WPF controls; the view supplies the playback controller (via <see cref="MainWindowViewModel(Func{VideoPlayerController})"/>) and reacts to <see cref="SearchBoxFocusRequested"/> and <see cref="CameraViewsViewModel.SelectedCameraView"/> changes.
 /// </summary>
 public partial class MainWindowViewModel : ObservableObject
 {
-    /// <summary>
-    /// The multi-camera grid pseudo-view.
-    /// Every other view id is a canonical camera name from <see cref="CameraNames"/>, so the selected view maps 1:1 onto the clip's camera files.
-    /// </summary>
-    public const string GridCameraView = "grid";
-
-    // The classic four-camera set (HW3 and earlier) shown before any clip is opened, so the selector strip doesn't start empty.
-    private static readonly string[] DefaultCameras =
-    [
-        CameraNames.Front,
-        CameraNames.Back,
-        CameraNames.LeftRepeater,
-        CameraNames.RightRepeater,
-    ];
-
     private readonly List<CamClip> _allClips = [];
     private readonly FlyleafRuntime _flyleafRuntime = new();
     private readonly Func<VideoPlayerController> _playerControllerFactory;
@@ -92,8 +77,6 @@ public MainWindowViewModel(
         };
         _filterDebounceTimer.Tick += OnFilterDebounceTick;
 
-        SyncCameraViewSelection();
-
         Error.PropertyChanged += (_, e) =>
         {
             if (e.PropertyName == nameof(ErrorOverlayViewModel.IsVisible))
@@ -121,6 +104,11 @@ public MainWindowViewModel(
     /// </summary>
     public AboutViewModel About { get; } = new();
 
+    /// <summary>
+    /// The enlarged camera (or grid) and the strip of cameras the current clip recorded.
+    /// </summary>
+    public CameraViewsViewModel Cameras { get; } = new();
+
     public bool ShowMainContent => !ShowAboutPage;
 
     /// <summary>
@@ -225,27 +213,6 @@ public string PositionText
 
     public bool HasNoClipSelected => SelectedClip is null && !IsLoading && !Error.IsVisible;
 
-    public bool IsGridViewSelected => SelectedCameraView == GridCameraView;
-
-    public bool IsSingleCameraViewSelected => !IsGridViewSelected;
-
-    public string ActiveCameraLabel => SelectedCameraView == GridCameraView ? "Grid" : CameraLabel(SelectedCameraView);
-
-    /// <summary>
-    /// Friendly tile label for a camera.
-    /// The classic four keep their short historical names; the HW4/AI4 B-pillars are spelled out to distinguish them from the repeaters.
-    /// </summary>
-    private static string CameraLabel(string camera) => camera switch
-    {
-        CameraNames.Front => "Front",
-        CameraNames.Back => "Rear",
-        CameraNames.LeftRepeater => "Left",
-        CameraNames.RightRepeater => "Right",
-        CameraNames.LeftPillar => "Left Pillar",
-        CameraNames.RightPillar => "Right Pillar",
-        _ => CameraNames.DisplayName(camera),
-    };
-
     // --- Seek-bar overlays for the selected clip (event moment + chunk seams + gaps) ---
     // Recomputed whenever the selection changes or the controller opens/replaces its media source; plain fields (not ObservableProperty) because they're derived, not independently settable.
     private double? _eventPosition;
@@ -410,53 +377,6 @@ public string SelectionDurationText
     [NotifyCanExecuteChangedFor(nameof(DecreaseSpeedCommand))]
     private double _playbackSpeed = 1.0;
 
-    [ObservableProperty]
-    [NotifyPropertyChangedFor(nameof(IsGridViewSelected))]
-    [NotifyPropertyChangedFor(nameof(IsSingleCameraViewSelected))]
-    [NotifyPropertyChangedFor(nameof(ActiveCameraLabel))]
-    private string _selectedCameraView = CameraNames.Front;
-
-    /// <summary>
-    /// The selectable views for the current clip: the grid plus one tile per camera the clip actually recorded, in <see cref="CameraNames.All"/> order.
-    /// The view re-parents its Flyleaf hosts into the tiles when this changes.
-    /// </summary>
-    [ObservableProperty]
-    private IReadOnlyList<CameraViewOption> _cameraViewOptions = BuildCameraViewOptions(null);
-
-    private static IReadOnlyList<CameraViewOption> BuildCameraViewOptions(CamClip clip)
-    {
-        // Only recognized cameras get a tile: each needs a dedicated Flyleaf host wired in the view, so an unknown future suffix is ingested and played in the engine but not shown.
-        var cameras = clip is null
-            ? DefaultCameras
-            : CameraNames.All.Where(camera => clip.Chunks.Any(chunk => chunk.Files.ContainsKey(camera))).ToArray();
-
-        // Metadata-only clips (no camera files at all) keep the classic strip rather than none.
-        if (cameras.Length == 0)
-        {
-            cameras = DefaultCameras;
-        }
-
-        var options = new List<CameraViewOption>(cameras.Length + 1)
-        {
-            new(GridCameraView, "Grid", shortcutNumber: 1, isGrid: true),
-        };
-        options.AddRange(cameras.Select((camera, index) => new CameraViewOption(camera, CameraLabel(camera), index + 2)));
-        return options;
-    }
-
-    private bool IsAvailableView(string view) =>
-        view is not null && CameraViewOptions.Any(option => option.ViewId == view);
-
-    partial void OnSelectedCameraViewChanged(string value) => SyncCameraViewSelection();
-
-    private void SyncCameraViewSelection()
-    {
-        foreach (var option in CameraViewOptions)
-        {
-            option.IsSelected = option.ViewId == SelectedCameraView;
-        }
-    }
-
     public async Task InitializeAsync()
     {
         if (_isInitialized)
@@ -843,7 +763,7 @@ private async Task ExportSelectionAsync()
 
         var start = TimeSpan.FromSeconds(startFraction * mediaSource.Duration.TotalSeconds);
         var end = TimeSpan.FromSeconds(endFraction * mediaSource.Duration.TotalSeconds);
-        var camera = ActiveExportCameraName;
+        var camera = Cameras.ExportCamera;
         var defaultFileName = $"{clip.Name} {CameraNames.DisplayName(camera)} {FormatTimeSpanForFileName(start)}-{FormatTimeSpanForFileName(end)}.mp4";
 
         await ExportAsync(clip, mediaSource, camera, start, end, defaultFileName);
@@ -938,9 +858,6 @@ private async Task ExportAsync(CamClip clip, ClipMediaSource mediaSource, string
         }
     }
 
-    // The currently enlarged camera; grid view exports the front (primary) angle.
-    private string ActiveExportCameraName => SelectedCameraView == GridCameraView ? CameraNames.Front : SelectedCameraView;
-
     private static string PickSavePathWithDialog(string defaultFileName)
     {
         var dialog = new SaveFileDialog
@@ -1073,7 +990,7 @@ private async Task PlaySelectedClipAsync(CamClip clip, CancellationToken cancell
             // Auto-focus the camera that triggered the event (Full metadata mode).
             if (clip.Event is not null)
             {
-                SelectedCameraView = CameraIdToView(clip.Event.Camera);
+                Cameras.SelectedCameraView = Cameras.CameraIdToView(clip.Event.Camera);
             }
         }
         catch (Exception ex)
@@ -1187,10 +1104,10 @@ private Func<Task> ResolveKeyAction(Key key, ModifierKeys modifiers)
                 _ => 0,
             };
 
-            var numberedOption = CameraViewOptions.FirstOrDefault(option => option.ShortcutNumber == shortcutNumber);
+            var numberedOption = Cameras.CameraViewOptions.FirstOrDefault(option => option.ShortcutNumber == shortcutNumber);
             if (numberedOption is not null)
             {
-                return Run(() => SelectCameraView(numberedOption.ViewId));
+                return Run(() => Cameras.SelectCameraViewCommand.Execute(numberedOption.ViewId));
             }
 
             if (key == Key.E && HasEventMarker)
@@ -1531,31 +1448,6 @@ private void ClearFilter()
         FilterText = string.Empty;
     }
 
-    [RelayCommand]
-    private void SelectCameraView(string cameraView)
-    {
-        // Unknown views and cameras the current clip didn't record fall back to the front (primary) angle, which every playable clip has.
-        SelectedCameraView = IsAvailableView(cameraView) ? cameraView : CameraNames.Front;
-    }
-
-    // Maps a Tesla event.json camera id to the camera view to auto-focus.
-    // Ids follow the community-documented map (0 front, 3/4 repeaters, 5/6 B-pillars, 7 rear; 1/2/8 are the non-recorded fisheye/narrow/cabin).
-    // Unknown ids and cameras this clip didn't record fall back to the front (primary) angle.
-    internal string CameraIdToView(int cameraId)
-    {
-        var camera = cameraId switch
-        {
-            3 => CameraNames.LeftRepeater,
-            4 => CameraNames.RightRepeater,
-            5 => CameraNames.LeftPillar,
-            6 => CameraNames.RightPillar,
-            7 => CameraNames.Back,
-            _ => CameraNames.Front,
-        };
-
-        return IsAvailableView(camera) ? camera : CameraNames.Front;
-    }
-
     private static bool CanUseClip(CamClip clip)
     {
         return clip is not null;
@@ -1693,18 +1585,7 @@ private void InvokeOnDispatcher(Action action)
 
     partial void OnSelectedClipChanged(CamClip value)
     {
-        // Rebuild the camera tiles from what this clip actually recorded (four on HW3, six on HW4/AI4).
-        // If the previously watched camera doesn't exist here, fall back to the front.
-        CameraViewOptions = BuildCameraViewOptions(value);
-        if (IsAvailableView(SelectedCameraView))
-        {
-            // Same view id as before, but the option objects are new, so re-mark the selected one.
-            SyncCameraViewSelection();
-        }
-        else
-        {
-            SelectedCameraView = CameraNames.Front;
-        }
+        Cameras.ShowCamerasOf(value);
 
         // In/out marks are fractions of the previous clip's timeline; they mean nothing on the new one, and a trim panel guiding a cut of the old clip would now be lying.
         CancelTrim();
diff --git a/SentryDeck/ViewModels/CameraViewsViewModel.cs b/SentryDeck/ViewModels/CameraViewsViewModel.cs
new file mode 100644
index 0000000..c18bc48
--- /dev/null
+++ b/SentryDeck/ViewModels/CameraViewsViewModel.cs
@@ -0,0 +1,147 @@
+using CommunityToolkit.Mvvm.ComponentModel;
+using CommunityToolkit.Mvvm.Input;
+
+namespace SentryDeck;
+
+/// <summary>
+/// Which camera is enlarged (or the grid), and the selector strip of cameras the current clip recorded.
+/// The view re-parents its Flyleaf hosts whenever <see cref="SelectedCameraView"/> or <see cref="CameraViewOptions"/> changes.
+/// </summary>
+public sealed partial class CameraViewsViewModel : ObservableObject
+{
+    /// <summary>
+    /// The multi-camera grid pseudo-view.
+    /// Every other view id is a canonical camera name from <see cref="CameraNames"/>, so the selected view maps 1:1 onto the clip's camera files.
+    /// </summary>
+    public const string GridCameraView = "grid";
+
+    // The classic four-camera set (HW3 and earlier) shown before any clip is opened, so the selector strip doesn't start empty.
+    private static readonly string[] DefaultCameras =
+    [
+        CameraNames.Front,
+        CameraNames.Back,
+        CameraNames.LeftRepeater,
+        CameraNames.RightRepeater,
+    ];
+
+    public CameraViewsViewModel()
+    {
+        SyncCameraViewSelection();
+    }
+
+    public bool IsGridViewSelected => SelectedCameraView == GridCameraView;
+
+    public bool IsSingleCameraViewSelected => !IsGridViewSelected;
+
+    public string ActiveCameraLabel => SelectedCameraView == GridCameraView ? "Grid" : CameraLabel(SelectedCameraView);
+
+    /// <summary>
+    /// The camera an export of what's on screen should use: the enlarged camera, or the front (primary) angle for the grid.
+    /// </summary>
+    public string ExportCamera => SelectedCameraView == GridCameraView ? CameraNames.Front : SelectedCameraView;
+
+    [ObservableProperty]
+    [NotifyPropertyChangedFor(nameof(IsGridViewSelected))]
+    [NotifyPropertyChangedFor(nameof(IsSingleCameraViewSelected))]
+    [NotifyPropertyChangedFor(nameof(ActiveCameraLabel))]
+    [NotifyPropertyChangedFor(nameof(ExportCamera))]
+    private string _selectedCameraView = CameraNames.Front;
+
+    /// <summary>
+    /// The selectable views for the current clip: the grid plus one tile per camera the clip actually recorded, in <see cref="CameraNames.All"/> order.
+    /// </summary>
+    [ObservableProperty]
+    private IReadOnlyList<CameraViewOption> _cameraViewOptions = BuildCameraViewOptions(null);
+
+    /// <summary>
+    /// Rebuilds the camera tiles from what <paramref name="clip"/> actually recorded (four on HW3, six on HW4/AI4).
+    /// If the previously watched camera doesn't exist there, the view falls back to the front.
+    /// </summary>
+    public void ShowCamerasOf(CamClip clip)
+    {
+        CameraViewOptions = BuildCameraViewOptions(clip);
+        if (IsAvailableView(SelectedCameraView))
+        {
+            // Same view id as before, but the option objects are new, so re-mark the selected one.
+            SyncCameraViewSelection();
+        }
+        else
+        {
+            SelectedCameraView = CameraNames.Front;
+        }
+    }
+
+    // Maps a Tesla event.json camera id to the camera view to auto-focus.
+    // Ids follow the community-documented map (0 front, 3/4 repeaters, 5/6 B-pillars, 7 rear; 1/2/8 are the non-recorded fisheye/narrow/cabin).
+    // Unknown ids and cameras this clip didn't record fall back to the front (primary) angle.
+    internal string CameraIdToView(int cameraId)
+    {
+        var camera = cameraId switch
+        {
+            3 => CameraNames.LeftRepeater,
+            4 => CameraNames.RightRepeater,
+            5 => CameraNames.LeftPillar,
+            6 => CameraNames.RightPillar,
+            7 => CameraNames.Back,
+            _ => CameraNames.Front,
+        };
+
+        return IsAvailableView(camera) ? camera : CameraNames.Front;
+    }
+
+    [RelayCommand]
+    private void SelectCameraView(string cameraView)
+    {
+        // Unknown views and cameras the current clip didn't record fall back to the front (primary) angle, which every playable clip has.
+        SelectedCameraView = IsAvailableView(cameraView) ? cameraView : CameraNames.Front;
+    }
+
+    /// <summary>
+    /// Friendly tile label for a camera.
+    /// The classic four keep their short historical names; the HW4/AI4 B-pillars are spelled out to distinguish them from the repeaters.
+    /// </summary>
+    private static string CameraLabel(string camera) => camera switch
+    {
+        CameraNames.Front => "Front",
+        CameraNames.Back => "Rear",
+        CameraNames.LeftRepeater => "Left",
+        CameraNames.RightRepeater => "Right",
+        CameraNames.LeftPillar => "Left Pillar",
+        CameraNames.RightPillar => "Right Pillar",
+        _ => CameraNames.DisplayName(camera),
+    };
+
+    private static IReadOnlyList<CameraViewOption> BuildCameraViewOptions(CamClip clip)
+    {
+        // Only recognized cameras get a tile: each needs a dedicated Flyleaf host wired in the view, so an unknown future suffix is ingested and played in the engine but not shown.
+        var cameras = clip is null
+            ? DefaultCameras
+            : CameraNames.All.Where(camera => clip.Chunks.Any(chunk => chunk.Files.ContainsKey(camera))).ToArray();
+
+        // Metadata-only clips (no camera files at all) keep the classic strip rather than none.
+        if (cameras.Length == 0)
+        {
+            cameras = DefaultCameras;
+        }
+
+        var options = new List<CameraViewOption>(cameras.Length + 1)
+        {
+            new(GridCameraView, "Grid", shortcutNumber: 1, isGrid: true),
+        };
+        options.AddRange(cameras.Select((camera, index) => new CameraViewOption(camera, CameraLabel(camera), index + 2)));
+        return options;
+    }
+
+    private bool IsAvailableView(string view) =>
+        view is not null && CameraViewOptions.Any(option => option.ViewId == view);
+
+    partial void OnSelectedCameraViewChanged(string value) => SyncCameraViewSelection();
+
+    private void SyncCameraViewSelection()
+    {
+        foreach (var option in CameraViewOptions)
+        {
+            option.IsSelected = option.ViewId == SelectedCameraView;
+        }
+    }
+}

From cd58b36aeaf25327dd6e4f2d59c6044f5c6d4b13 Mon Sep 17 00:00:00 2001
From: Daniel Chalmers <daniel.chalmers@outlook.com>
Date: Thu, 24 Sep 2026 07:41:51 -0500
Subject: [PATCH 5/8] Move playback into its own view-model

PlaybackViewModel owns the player: loading the selected clip, transport commands, the seek gesture and scrubbing, the event marker, chunk seams and gap ticks, the now-playing badge, and speed. Siblings reach the player only through a small surface (the playlist, a raw stop, the open clip and its media source), and the player reports clip changes back through an event instead of writing the list selection itself.

IsLoading used to be one flag written by the clip scan, the FFmpeg download, and clip loading, which never overlap. The main view-model now computes it from the three, while CanSeek and the transport gates read only the playback part, which is the only part that was ever set whenever they could be true.
---
 .../MainWindowViewModelTests.Clips.cs         |  10 +-
 .../MainWindowViewModelTests.Keyboard.cs      |   6 +-
 .../MainWindowViewModelTests.Markers.cs       |  68 +-
 .../MainWindowViewModelTests.Playback.cs      |  66 +-
 .../MainWindowViewModelTests.Trimming.cs      |  86 +--
 SentryDeck.Tests/MainWindowViewModelTests.cs  |  34 +-
 SentryDeck/MainWindow.xaml                    |  58 +-
 SentryDeck/MainWindow.xaml.cs                 |   6 +-
 SentryDeck/MainWindowViewModel.cs             | 689 ++----------------
 SentryDeck/ViewModels/PlaybackViewModel.cs    | 644 ++++++++++++++++
 10 files changed, 889 insertions(+), 778 deletions(-)
 create mode 100644 SentryDeck/ViewModels/PlaybackViewModel.cs

diff --git a/SentryDeck.Tests/MainWindowViewModelTests.Clips.cs b/SentryDeck.Tests/MainWindowViewModelTests.Clips.cs
index e8df1b2..9c8e560 100644
--- a/SentryDeck.Tests/MainWindowViewModelTests.Clips.cs
+++ b/SentryDeck.Tests/MainWindowViewModelTests.Clips.cs
@@ -279,12 +279,12 @@ public async Task DeleteClip_TheSelectedClip_ClearsSelectionAndNowPlaying()
 
         var target = vm.FilteredClips[0];
         vm.SelectedClip = target; // sets NowPlayingClip too (see OnSelectedClipChanged)
-        vm.NowPlayingClip.ShouldBe(target);
+        vm.Playback.NowPlayingClip.ShouldBe(target);
 
         await vm.DeleteClipCommand.ExecuteAsync(target);
 
         vm.SelectedClip.ShouldBeNull();
-        vm.NowPlayingClip.ShouldBeNull();
+        vm.Playback.NowPlayingClip.ShouldBeNull();
         vm.FilteredClips.ShouldNotContain(target);
     }
 
@@ -336,13 +336,13 @@ public async Task DeleteClip_TheOpenClip_StopsPlaybackBeforeRecycling()
         var closesWhenRecycled = -1;
         vm.ConfirmDeleteClip = _ => true;
         vm.RecycleClipFolder = _ => closesWhenRecycled = front.Count("close");
-        vm.SeekPosition = 0.5;
+        vm.Playback.SeekPosition = 0.5;
 
         await vm.DeleteClipCommand.ExecuteAsync(clipFiles.Clip);
 
         // Windows can't recycle a folder whose files are still locked, so playback must already be stopped when the shell operation runs -- not merely by the time delete returns.
         closesWhenRecycled.ShouldBeGreaterThan(closesBeforeDelete);
-        vm.SeekPosition.ShouldBe(0);
+        vm.Playback.SeekPosition.ShouldBe(0);
     }
 
     [Fact]
@@ -359,7 +359,7 @@ public async Task DeleteClip_TheOpenClip_RemovesItFromThePlayerPlaylist()
 
         // Next/Previous walk the controller's playlist, so a deleted clip left behind in it would navigate straight back to a folder that no longer exists.
         controller.Playlist.Clips.ShouldNotContain(clip);
-        vm.NowPlayingClip.ShouldBeNull();
+        vm.Playback.NowPlayingClip.ShouldBeNull();
         vm.SelectedClip.ShouldBeNull();
     }
 
diff --git a/SentryDeck.Tests/MainWindowViewModelTests.Keyboard.cs b/SentryDeck.Tests/MainWindowViewModelTests.Keyboard.cs
index 2d6fea3..1282335 100644
--- a/SentryDeck.Tests/MainWindowViewModelTests.Keyboard.cs
+++ b/SentryDeck.Tests/MainWindowViewModelTests.Keyboard.cs
@@ -107,10 +107,10 @@ public void StopCommand_ClearsNowPlayingClip()
         var closesAfterOpen = front.Count("close");
         vm.SelectedClip = clipFiles.Clip; // sets NowPlayingClip too (see OnSelectedClipChanged)
 
-        RunPinnedToTestThread(() => vm.StopCommand.ExecuteAsync(null));
+        RunPinnedToTestThread(() => vm.Playback.StopCommand.ExecuteAsync(null));
 
         // Stop is the only thing that takes the now-playing badge off the clip list; leaving it set would mark a clip as playing with nothing loaded.
-        vm.NowPlayingClip.ShouldBeNull();
+        vm.Playback.NowPlayingClip.ShouldBeNull();
         front.Count("close").ShouldBeGreaterThan(closesAfterOpen);
     }
 
@@ -162,7 +162,7 @@ public async Task SupersededSelection_DoesNotClearTheNewerLoadsLoadingState()
         // The superseded load is dropped on its way out, and the loading state it finds is no longer its own to clear -- doing so would strand the newer clip's open with no progress indication at all.
         await Wait.UntilAsync(() => vm.Cameras.SelectedCameraView == CameraNames.Back);
         vm.IsLoading.ShouldBeTrue();
-        vm.NowPlayingClip.ShouldBe(winner);
+        vm.Playback.NowPlayingClip.ShouldBe(winner);
         vm.SelectedClip.ShouldBe(winner);
     }
 
diff --git a/SentryDeck.Tests/MainWindowViewModelTests.Markers.cs b/SentryDeck.Tests/MainWindowViewModelTests.Markers.cs
index 3c13c52..61c6230 100644
--- a/SentryDeck.Tests/MainWindowViewModelTests.Markers.cs
+++ b/SentryDeck.Tests/MainWindowViewModelTests.Markers.cs
@@ -16,9 +16,9 @@ public void EventMarker_NearClipEnd_MapsToHighFraction()
         // 10 one-minute chunks (600s modeled); event at 9m30s in -> 0.95.
         vm.SelectedClip = ClipWithChunksAndEvent(10, TimeSpan.FromSeconds(570));
 
-        vm.HasEventMarker.ShouldBeTrue();
-        vm.EventMarkerPosition.ShouldBe(0.95, 0.0001);
-        vm.EventMarkerTooltip.ShouldStartWith("Honk · ");
+        vm.Playback.HasEventMarker.ShouldBeTrue();
+        vm.Playback.EventMarkerPosition.ShouldBe(0.95, 0.0001);
+        vm.Playback.EventMarkerTooltip.ShouldStartWith("Honk · ");
     }
 
     [Fact]
@@ -28,9 +28,9 @@ public void EventMarker_AbsentWithoutEvent()
 
         vm.SelectedClip = ClipWithChunks(3);
 
-        vm.HasEventMarker.ShouldBeFalse();
-        vm.EventMarkerPosition.ShouldBe(0);
-        vm.EventMarkerTooltip.ShouldBeEmpty();
+        vm.Playback.HasEventMarker.ShouldBeFalse();
+        vm.Playback.EventMarkerPosition.ShouldBe(0);
+        vm.Playback.EventMarkerTooltip.ShouldBeEmpty();
     }
 
     [Fact]
@@ -42,7 +42,7 @@ public void EventMarker_AbsentWhenEventTimestampIsDefault()
 
         vm.SelectedClip = new CamClip(System.IO.Path.GetTempPath(), "Default TS", new DateTime(2025, 1, 1, 12, 0, 0), chunks, camEvent);
 
-        vm.HasEventMarker.ShouldBeFalse();
+        vm.Playback.HasEventMarker.ShouldBeFalse();
     }
 
     [Fact]
@@ -53,8 +53,8 @@ public void EventMarker_AtTheVeryStart_ShowsAtFractionZero()
         // Event fired on the first recorded frame (timestamp == first chunk's timestamp): fraction is exactly 0, which is a real position, not clock skew.
         vm.SelectedClip = ClipWithChunksAndEvent(10, TimeSpan.Zero);
 
-        vm.HasEventMarker.ShouldBeTrue();
-        vm.EventMarkerPosition.ShouldBe(0);
+        vm.Playback.HasEventMarker.ShouldBeTrue();
+        vm.Playback.EventMarkerPosition.ShouldBe(0);
     }
 
     [Fact]
@@ -65,7 +65,7 @@ public void EventMarker_AbsentWhenEventBeforeClipStart()
         // Clock skew: event five minutes before the first chunk -> fraction <= 0, no marker.
         vm.SelectedClip = ClipWithChunksAndEvent(10, TimeSpan.FromMinutes(-5));
 
-        vm.HasEventMarker.ShouldBeFalse();
+        vm.Playback.HasEventMarker.ShouldBeFalse();
     }
 
     [Fact]
@@ -76,7 +76,7 @@ public void EventMarker_AbsentWhenEventBeyondModeledDuration()
         // 3 chunks = 180s modeled; an event at 200s is past the estimated end (fraction > 1).
         vm.SelectedClip = ClipWithChunksAndEvent(3, TimeSpan.FromSeconds(200));
 
-        vm.HasEventMarker.ShouldBeFalse();
+        vm.Playback.HasEventMarker.ShouldBeFalse();
     }
 
     [Fact]
@@ -87,9 +87,9 @@ public void EventMarker_AbsentWhenNoChunks_NoDivideByZero()
 
         vm.SelectedClip = new CamClip(System.IO.Path.GetTempPath(), "No Chunks", new DateTime(2025, 1, 1, 12, 0, 0), [], camEvent);
 
-        vm.HasEventMarker.ShouldBeFalse();
-        vm.EventMarkerPosition.ShouldBe(0);
-        vm.ChunkBoundaries.ShouldBeEmpty();
+        vm.Playback.HasEventMarker.ShouldBeFalse();
+        vm.Playback.EventMarkerPosition.ShouldBe(0);
+        vm.Playback.ChunkBoundaries.ShouldBeEmpty();
     }
 
     [Fact]
@@ -99,9 +99,9 @@ public void ChunkBoundaries_AreInteriorFractions()
 
         vm.SelectedClip = ClipWithChunks(3);
 
-        vm.ChunkBoundaries.Count.ShouldBe(2);
-        vm.ChunkBoundaries[0].ShouldBe(1.0 / 3, 0.0001);
-        vm.ChunkBoundaries[1].ShouldBe(2.0 / 3, 0.0001);
+        vm.Playback.ChunkBoundaries.Count.ShouldBe(2);
+        vm.Playback.ChunkBoundaries[0].ShouldBe(1.0 / 3, 0.0001);
+        vm.Playback.ChunkBoundaries[1].ShouldBe(2.0 / 3, 0.0001);
     }
 
     [Fact]
@@ -111,7 +111,7 @@ public void ChunkBoundaries_EmptyForSingleChunk()
 
         vm.SelectedClip = ClipWithChunks(1);
 
-        vm.ChunkBoundaries.ShouldBeEmpty();
+        vm.Playback.ChunkBoundaries.ShouldBeEmpty();
     }
 
     // --- Gap-aware markers: once the controller has actually opened the clip's media, event/gap positions come from the real ClipMediaSource (probed durations + wall-clock mapping) rather than the uniform-chunk-length estimate used before the media opens. ---
@@ -124,7 +124,7 @@ public void GapPositions_EmptyBeforeMediaOpens()
 
         vm.SelectedClip = ClipWithChunksAndEvent(3, TimeSpan.FromSeconds(90));
 
-        vm.GapPositions.ShouldBeEmpty();
+        vm.Playback.GapPositions.ShouldBeEmpty();
     }
 
     [Fact]
@@ -140,7 +140,7 @@ public void GapPositions_ReflectAGapOnceMediaSourceIsOpen()
         vm.SelectedClip = clip;
 
         // Two included chunks of 60s each = 120s total; the single gap sits at media time 60s.
-        vm.GapPositions.ShouldBe([60.0 / 120], 0.0001);
+        vm.Playback.GapPositions.ShouldBe([60.0 / 120], 0.0001);
     }
 
     [Fact]
@@ -157,11 +157,11 @@ public void EventMarker_AfterAGap_UsesGapCorrectedFraction_NotLinearTime()
         var (vm, _, _) = CreateViewModelWithOpenedClip(clip);
         vm.SelectedClip = clip;
 
-        vm.HasEventMarker.ShouldBeTrue();
-        vm.EventMarkerPosition.ShouldBe(70.0 / 120, 0.0001);
+        vm.Playback.HasEventMarker.ShouldBeTrue();
+        vm.Playback.EventMarkerPosition.ShouldBe(70.0 / 120, 0.0001);
 
         // Sanity check that this genuinely differs from what the naive linear/estimated model (ignoring the gap) would have produced, so the test would fail if gap-awareness regressed.
-        Math.Abs(vm.EventMarkerPosition - (130.0 / 180)).ShouldBeGreaterThan(0.01);
+        Math.Abs(vm.Playback.EventMarkerPosition - (130.0 / 180)).ShouldBeGreaterThan(0.01);
     }
 
     [Fact]
@@ -169,24 +169,24 @@ public void ClearingSelection_ResetsEventMarkerAndChunks()
     {
         var vm = CreateViewModel();
         vm.SelectedClip = ClipWithChunksAndEvent(10, TimeSpan.FromSeconds(570));
-        vm.HasEventMarker.ShouldBeTrue();
+        vm.Playback.HasEventMarker.ShouldBeTrue();
 
         vm.SelectedClip = null;
 
-        vm.HasEventMarker.ShouldBeFalse();
-        vm.EventMarkerPosition.ShouldBe(0);
-        vm.ChunkBoundaries.ShouldBeEmpty();
+        vm.Playback.HasEventMarker.ShouldBeFalse();
+        vm.Playback.EventMarkerPosition.ShouldBe(0);
+        vm.Playback.ChunkBoundaries.ShouldBeEmpty();
     }
 
     [Fact]
     public void JumpToEvent_CanExecute_FollowsHasEventMarker()
     {
         var vm = CreateViewModel();
-        vm.JumpToEventCommand.CanExecute(null).ShouldBeFalse();
+        vm.Playback.JumpToEventCommand.CanExecute(null).ShouldBeFalse();
 
         vm.SelectedClip = ClipWithChunksAndEvent(10, TimeSpan.FromSeconds(570));
 
-        vm.JumpToEventCommand.CanExecute(null).ShouldBeTrue();
+        vm.Playback.JumpToEventCommand.CanExecute(null).ShouldBeTrue();
     }
 
     [Fact]
@@ -209,7 +209,7 @@ public void EventShortcut_WithAnOpenedEventClip_SeeksThePlayersToTheEventMoment(
         handled.ShouldBeTrue();
         front.Seeks[^1].Position.ShouldBe(TimeSpan.FromSeconds(90));
         controller.Position.ShouldBe(TimeSpan.FromSeconds(90));
-        vm.SeekPosition.ShouldBe(0.5, 0.0001);
+        vm.Playback.SeekPosition.ShouldBe(0.5, 0.0001);
     }
 
     [Fact]
@@ -228,12 +228,12 @@ public void SelectingClip_RaisesEventMarkerNotifications()
     {
         var vm = CreateViewModel();
         var changed = new List<string>();
-        vm.PropertyChanged += (_, e) => changed.Add(e.PropertyName);
+        vm.Playback.PropertyChanged += (_, e) => changed.Add(e.PropertyName);
 
         vm.SelectedClip = ClipWithChunksAndEvent(5, TimeSpan.FromSeconds(250));
 
-        changed.ShouldContain(nameof(MainWindowViewModel.EventMarkerPosition));
-        changed.ShouldContain(nameof(MainWindowViewModel.HasEventMarker));
-        changed.ShouldContain(nameof(MainWindowViewModel.ChunkBoundaries));
+        changed.ShouldContain(nameof(PlaybackViewModel.EventMarkerPosition));
+        changed.ShouldContain(nameof(PlaybackViewModel.HasEventMarker));
+        changed.ShouldContain(nameof(PlaybackViewModel.ChunkBoundaries));
     }
 }
diff --git a/SentryDeck.Tests/MainWindowViewModelTests.Playback.cs b/SentryDeck.Tests/MainWindowViewModelTests.Playback.cs
index 5f7d5fb..5cfd90b 100644
--- a/SentryDeck.Tests/MainWindowViewModelTests.Playback.cs
+++ b/SentryDeck.Tests/MainWindowViewModelTests.Playback.cs
@@ -14,24 +14,24 @@ public void SeekMath_PositionTextScalesByDuration()
         var vm = CreateViewModelWithController(out var controller, out _);
         controller.Duration = TimeSpan.FromMinutes(2);
 
-        vm.SeekPosition = 0.5;
+        vm.Playback.SeekPosition = 0.5;
 
-        vm.PositionText.ShouldBe("1:00");
-        vm.DurationText.ShouldBe("2:00");
+        vm.Playback.PositionText.ShouldBe("1:00");
+        vm.Playback.DurationText.ShouldBe("2:00");
     }
 
     [Fact]
     public void CanSeek_RequiresOpenMediaDurationAndNotLoading()
     {
         var vm = CreateViewModelWithController(out var controller, out _);
-        vm.CanSeek.ShouldBeFalse(); // no media open yet
+        vm.Playback.CanSeek.ShouldBeFalse(); // no media open yet
 
         controller.Duration = TimeSpan.FromMinutes(1);
         controller.IsMediaOpen = true;
-        vm.CanSeek.ShouldBeTrue();
+        vm.Playback.CanSeek.ShouldBeTrue();
 
-        vm.IsLoading = true;
-        vm.CanSeek.ShouldBeFalse();
+        vm.Playback.IsLoading = true;
+        vm.Playback.CanSeek.ShouldBeFalse();
     }
 
     [Fact]
@@ -42,7 +42,7 @@ public void ControllerPositionChange_UpdatesSeekPosition()
 
         controller.Position = TimeSpan.FromSeconds(30);
 
-        vm.SeekPosition.ShouldBe(0.25, 0.0001);
+        vm.Playback.SeekPosition.ShouldBe(0.25, 0.0001);
     }
 
     [Fact]
@@ -52,13 +52,13 @@ public async Task WhileScrubbing_ControllerPositionDoesNotMoveTheSlider()
         controller.Duration = TimeSpan.FromMinutes(2);
         controller.IsMediaOpen = true;
 
-        vm.BeginSeek();
+        vm.Playback.BeginSeek();
         controller.Position = TimeSpan.FromSeconds(60); // user is dragging: ignore controller updates
-        vm.SeekPosition.ShouldBe(0.0);
+        vm.Playback.SeekPosition.ShouldBe(0.0);
 
-        await vm.EndSeekAsync();
+        await vm.Playback.EndSeekAsync();
         controller.Position = TimeSpan.FromSeconds(30); // updates resume after the drag
-        vm.SeekPosition.ShouldBe(0.25, 0.0001);
+        vm.Playback.SeekPosition.ShouldBe(0.25, 0.0001);
     }
 
     // Synchronous (no async/await in the test body itself -- see RunPinnedToTestThread).
@@ -68,14 +68,14 @@ public void DragSequence_IssuesFastSeeks_ReleaseIssuesAccurateSeekAtReleasePosit
         using var clipFiles = TestClipFiles.Create(chunkCount: 1); // 60s clip (see TestClipFiles)
         var (vm, _, front) = CreateViewModelWithOpenedClip(clipFiles.Clip);
 
-        vm.BeginSeek();
+        vm.Playback.BeginSeek();
 
         // Simulate a drag: each slider value change while dragging should scrub-seek (fast/keyframe).
-        vm.SeekPosition = 0.2; // 12s of 60s
-        vm.OnSeekSliderValueChanged();
+        vm.Playback.SeekPosition = 0.2; // 12s of 60s
+        vm.Playback.OnSeekSliderValueChanged();
 
-        vm.SeekPosition = 0.5; // 30s
-        vm.OnSeekSliderValueChanged();
+        vm.Playback.SeekPosition = 0.5; // 30s
+        vm.Playback.OnSeekSliderValueChanged();
 
         front.Seeks.ShouldContain((TimeSpan.FromSeconds(12), false));
         front.Seeks.ShouldContain((TimeSpan.FromSeconds(30), false));
@@ -84,9 +84,9 @@ public void DragSequence_IssuesFastSeeks_ReleaseIssuesAccurateSeekAtReleasePosit
         front.Seeks.ShouldAllBe(seek => !seek.Accurate);
 
         // Release at 0.75 (45s): EndSeekAsync must issue exactly one ACCURATE seek at the release position.
-        vm.SeekPosition = 0.75;
+        vm.Playback.SeekPosition = 0.75;
 
-        RunPinnedToTestThread(vm.EndSeekAsync);
+        RunPinnedToTestThread(vm.Playback.EndSeekAsync);
 
         front.Seeks[^1].ShouldBe((TimeSpan.FromSeconds(45), true));
     }
@@ -98,28 +98,28 @@ public void StaleEndSeek_AfterANewDragStarted_DoesNotUnlockPositionSync()
         using var clipFiles = TestClipFiles.Create(chunkCount: 1); // 60s clip
         var (vm, _, front) = CreateViewModelWithOpenedClip(clipFiles.Clip);
 
-        vm.BeginSeek();
-        vm.SeekPosition = 0.5;
+        vm.Playback.BeginSeek();
+        vm.Playback.SeekPosition = 0.5;
 
         // While gesture #1's accurate release seek is executing, the user grabs the thumb again and starts a new drag.
         // Gesture #1's completion is then stale: it must NOT clear the active drag's seeking state, or the position sync would yank the thumb mid-drag.
         front.SeekCallback = () =>
         {
             front.SeekCallback = null;
-            vm.BeginSeek();
-            vm.SeekPosition = 0.25;
+            vm.Playback.BeginSeek();
+            vm.Playback.SeekPosition = 0.25;
         };
 
-        RunPinnedToTestThread(vm.EndSeekAsync);
+        RunPinnedToTestThread(vm.Playback.EndSeekAsync);
 
         // A controller position sync arriving during drag #2 must still be ignored.
         front.RaisePositionChanged(TimeSpan.FromSeconds(50));
-        vm.SeekPosition.ShouldBe(0.25);
+        vm.Playback.SeekPosition.ShouldBe(0.25);
 
         // The active gesture still ends normally and re-enables position sync.
-        RunPinnedToTestThread(vm.EndSeekAsync);
+        RunPinnedToTestThread(vm.Playback.EndSeekAsync);
         front.RaisePositionChanged(TimeSpan.FromSeconds(30));
-        vm.SeekPosition.ShouldBe(0.5, 0.0001);
+        vm.Playback.SeekPosition.ShouldBe(0.5, 0.0001);
     }
 
     [Fact]
@@ -132,7 +132,7 @@ public void PositionSync_WhenNotDragging_DoesNotTriggerScrubSeeks()
 
         // Playback position advances on its own (not a drag): SeekPosition updates via the controller -> UpdateSeekPositionFromController path, which does not go through OnSeekSliderValueChanged, so no scrub seek should ever be issued.
         controller.Position = TimeSpan.FromSeconds(10);
-        vm.OnSeekSliderValueChanged(); // the view raises ValueChanged for programmatic changes too
+        vm.Playback.OnSeekSliderValueChanged(); // the view raises ValueChanged for programmatic changes too
 
         front.Seeks.Count.ShouldBe(seeksBefore);
     }
@@ -147,8 +147,8 @@ public void ControllerLoadingAndPlaying_MirrorToViewModel()
 
         controller.IsLoading = false;
         controller.IsPlaying = true;
-        vm.IsPlaying.ShouldBeTrue();
-        vm.PlayPauseIcon.ShouldBe(""); // Pause
+        vm.Playback.IsPlaying.ShouldBeTrue();
+        vm.Playback.PlayPauseIcon.ShouldBe(""); // Pause
     }
 
     [Fact]
@@ -170,8 +170,8 @@ public void CanGoNextPrevious_ReflectControllerPlaylist()
         controller.LoadClips(TestClips.Create(3)); // set the playlist directly (synchronous, on the test thread)
 
         // Playlist loaded, nothing playing yet: can advance, can't go back.
-        vm.CanGoNext.ShouldBeTrue();
-        vm.CanGoPrevious.ShouldBeFalse();
+        vm.Playback.CanGoNext.ShouldBeTrue();
+        vm.Playback.CanGoPrevious.ShouldBeFalse();
     }
 
     [Fact]
@@ -215,7 +215,7 @@ public void StopCommand_WhileASelectionIsWaitingToLoad_KeepsItFromPlaying()
         vm.InitializePlayer();
 
         vm.SelectedClip = clipFiles.Clip;
-        RunPinnedToTestThread(() => vm.StopCommand.ExecuteAsync(null));
+        RunPinnedToTestThread(() => vm.Playback.StopCommand.ExecuteAsync(null));
         loadGate.SetResult();
         RunPinnedToTestThread(controller.WhenIdleAsync);
 
diff --git a/SentryDeck.Tests/MainWindowViewModelTests.Trimming.cs b/SentryDeck.Tests/MainWindowViewModelTests.Trimming.cs
index 6a10cf1..68f1097 100644
--- a/SentryDeck.Tests/MainWindowViewModelTests.Trimming.cs
+++ b/SentryDeck.Tests/MainWindowViewModelTests.Trimming.cs
@@ -15,14 +15,14 @@ public void MarkSelection_SetsFractions_AndCompletesTheRange()
         controller.Duration = TimeSpan.FromMinutes(1);
         controller.IsMediaOpen = true;
 
-        vm.SeekPosition = 0.3;
+        vm.Playback.SeekPosition = 0.3;
         vm.MarkSelectionStartCommand.Execute(null);
 
         vm.HasSelectionStart.ShouldBeTrue();
         vm.SelectionStartPosition.ShouldBe(0.3);
         vm.HasSelection.ShouldBeFalse(); // no end yet
 
-        vm.SeekPosition = 0.7;
+        vm.Playback.SeekPosition = 0.7;
         vm.MarkSelectionEndCommand.Execute(null);
 
         vm.HasSelection.ShouldBeTrue();
@@ -37,19 +37,19 @@ public void MarkSelection_InvertedOrder_ClearsTheOtherMark()
         controller.Duration = TimeSpan.FromMinutes(1);
         controller.IsMediaOpen = true;
 
-        vm.SeekPosition = 0.3;
+        vm.Playback.SeekPosition = 0.3;
         vm.MarkSelectionStartCommand.Execute(null);
-        vm.SeekPosition = 0.7;
+        vm.Playback.SeekPosition = 0.7;
         vm.MarkSelectionEndCommand.Execute(null);
 
         // A start at/past the end invalidates the end...
-        vm.SeekPosition = 0.9;
+        vm.Playback.SeekPosition = 0.9;
         vm.MarkSelectionStartCommand.Execute(null);
         vm.SelectionStartPosition.ShouldBe(0.9);
         vm.HasSelectionEnd.ShouldBeFalse();
 
         // ...and an end at/before the start invalidates the start.
-        vm.SeekPosition = 0.1;
+        vm.Playback.SeekPosition = 0.1;
         vm.MarkSelectionEndCommand.Execute(null);
         vm.SelectionEndPosition.ShouldBe(0.1);
         vm.HasSelectionStart.ShouldBeFalse();
@@ -64,7 +64,7 @@ public void ClearSelection_RemovesBothMarks()
 
         vm.ClearSelectionCommand.CanExecute(null).ShouldBeFalse(); // nothing to clear yet
 
-        vm.SeekPosition = 0.2;
+        vm.Playback.SeekPosition = 0.2;
         vm.MarkSelectionStartCommand.Execute(null);
         vm.HasAnySelectionMark.ShouldBeTrue();
 
@@ -81,7 +81,7 @@ public void Selection_ClearsWhenAnotherClipIsSelected()
         controller.Duration = TimeSpan.FromMinutes(1);
         controller.IsMediaOpen = true;
 
-        vm.SeekPosition = 0.2;
+        vm.Playback.SeekPosition = 0.2;
         vm.MarkSelectionStartCommand.Execute(null);
 
         vm.SelectedClip = TestClips.Create(1)[0];
@@ -95,16 +95,16 @@ public void TrimCommands_ReEnableWhenLoadingEndsLast()
         // Mirrors the real clip-open order: the controller reports Duration and IsMediaOpen while the view-model is still loading, so CanSeek only becomes true when IsLoading flips off.
         // Every CanSeek-gated command must be re-queried on that final transition: the Trim button shipped permanently disabled because it wasn't.
         var vm = CreateViewModelWithController(out var controller, out _);
-        vm.IsLoading = true;
+        vm.Playback.IsLoading = true;
         controller.Duration = TimeSpan.FromMinutes(1);
         controller.IsMediaOpen = true;
 
         var trimCanExecuteChanged = false;
         vm.ToggleTrimmingCommand.CanExecuteChanged += (_, _) => trimCanExecuteChanged = true;
 
-        vm.IsLoading = false;
+        vm.Playback.IsLoading = false;
 
-        vm.CanSeek.ShouldBeTrue();
+        vm.Playback.CanSeek.ShouldBeTrue();
         trimCanExecuteChanged.ShouldBeTrue();
         vm.ToggleTrimmingCommand.CanExecute(null).ShouldBeTrue();
         vm.MarkSelectionStartCommand.CanExecute(null).ShouldBeTrue();
@@ -120,7 +120,7 @@ public void MarkingAPoint_OpensTheTrimPanel()
 
         vm.IsTrimming.ShouldBeFalse();
 
-        vm.SeekPosition = 0.3;
+        vm.Playback.SeekPosition = 0.3;
         vm.MarkSelectionStartCommand.Execute(null);
 
         vm.IsTrimming.ShouldBeTrue();
@@ -137,7 +137,7 @@ public void ToggleTrimming_OpensEmpty_AndClosingDiscardsTheMarks()
         vm.IsTrimming.ShouldBeTrue();
         vm.HasAnySelectionMark.ShouldBeFalse();
 
-        vm.SeekPosition = 0.3;
+        vm.Playback.SeekPosition = 0.3;
         vm.MarkSelectionStartCommand.Execute(null);
 
         vm.ToggleTrimmingCommand.Execute(null); // acts as cancel while open
@@ -153,9 +153,9 @@ public void CancelTrim_ClosesThePanelAndDiscardsTheMarks()
         controller.Duration = TimeSpan.FromMinutes(1);
         controller.IsMediaOpen = true;
 
-        vm.SeekPosition = 0.3;
+        vm.Playback.SeekPosition = 0.3;
         vm.MarkSelectionStartCommand.Execute(null);
-        vm.SeekPosition = 0.7;
+        vm.Playback.SeekPosition = 0.7;
         vm.MarkSelectionEndCommand.Execute(null);
 
         vm.CancelTrimCommand.Execute(null);
@@ -186,11 +186,11 @@ public void TrimHintText_WalksThroughStartEndExport()
 
         vm.TrimHintText.ShouldContain("set the start");
 
-        vm.SeekPosition = 0.25;
+        vm.Playback.SeekPosition = 0.25;
         vm.MarkSelectionStartCommand.Execute(null);
         vm.TrimHintText.ShouldContain("set the end");
 
-        vm.SeekPosition = 0.75;
+        vm.Playback.SeekPosition = 0.75;
         vm.MarkSelectionEndCommand.Execute(null);
 
         // Half of a 2:00 clip is selected.
@@ -217,9 +217,9 @@ public void ExportSelection_SendsMediaTimeRangeAndActiveCameraToTheExporter()
         var (vm, _, _) = CreateViewModelWithOpenedClip(clipFiles.Clip, exporter, _ => @"C:\out\clip.mp4");
 
         vm.Cameras.SelectCameraViewCommand.Execute(CameraNames.Back);
-        vm.SeekPosition = 0.25;
+        vm.Playback.SeekPosition = 0.25;
         vm.MarkSelectionStartCommand.Execute(null);
-        vm.SeekPosition = 0.75;
+        vm.Playback.SeekPosition = 0.75;
         vm.MarkSelectionEndCommand.Execute(null);
 
         RunPinnedToTestThread(() => vm.ExportSelectionCommand.ExecuteAsync(null));
@@ -240,9 +240,9 @@ public void ExportSelection_SaveDialogCanceled_DoesNotExport()
         var exporter = new FakeClipExporter();
         var (vm, _, _) = CreateViewModelWithOpenedClip(clipFiles.Clip, exporter, _ => null);
 
-        vm.SeekPosition = 0.25;
+        vm.Playback.SeekPosition = 0.25;
         vm.MarkSelectionStartCommand.Execute(null);
-        vm.SeekPosition = 0.75;
+        vm.Playback.SeekPosition = 0.75;
         vm.MarkSelectionEndCommand.Execute(null);
 
         RunPinnedToTestThread(() => vm.ExportSelectionCommand.ExecuteAsync(null));
@@ -258,9 +258,9 @@ public void ExportSelection_ExporterFailure_ShowsErrorAndResetsBusyState()
         var exporter = new FakeClipExporter { ExceptionToThrow = new InvalidOperationException("ffmpeg exploded") };
         var (vm, _, _) = CreateViewModelWithOpenedClip(clipFiles.Clip, exporter, _ => @"C:\out\clip.mp4");
 
-        vm.SeekPosition = 0.25;
+        vm.Playback.SeekPosition = 0.25;
         vm.MarkSelectionStartCommand.Execute(null);
-        vm.SeekPosition = 0.75;
+        vm.Playback.SeekPosition = 0.75;
         vm.MarkSelectionEndCommand.Execute(null);
 
         RunPinnedToTestThread(() => vm.ExportSelectionCommand.ExecuteAsync(null));
@@ -361,35 +361,35 @@ public void SaveEventClip_RequiresAnEventMoment()
     public void SpeedStepper_WalksTheLadder_AndClampsAtTheEnds()
     {
         var vm = CreateViewModel();
-        vm.PlaybackSpeed.ShouldBe(1.0);
+        vm.Playback.PlaybackSpeed.ShouldBe(1.0);
 
-        vm.IncreaseSpeedCommand.Execute(null);
-        vm.PlaybackSpeed.ShouldBe(1.25);
+        vm.Playback.IncreaseSpeedCommand.Execute(null);
+        vm.Playback.PlaybackSpeed.ShouldBe(1.25);
 
         // Run the ladder up: it must stop at the top step (Flyleaf's 16x clamp).
         for (var i = 0; i < 20; i++)
-            vm.IncreaseSpeedCommand.Execute(null);
-        vm.PlaybackSpeed.ShouldBe(16.0);
-        vm.CanIncreaseSpeed.ShouldBeFalse();
-        vm.IncreaseSpeedCommand.CanExecute(null).ShouldBeFalse();
+            vm.Playback.IncreaseSpeedCommand.Execute(null);
+        vm.Playback.PlaybackSpeed.ShouldBe(16.0);
+        vm.Playback.CanIncreaseSpeed.ShouldBeFalse();
+        vm.Playback.IncreaseSpeedCommand.CanExecute(null).ShouldBeFalse();
 
         // And back down to the bottom step.
         for (var i = 0; i < 20; i++)
-            vm.DecreaseSpeedCommand.Execute(null);
-        vm.PlaybackSpeed.ShouldBe(0.25);
-        vm.CanDecreaseSpeed.ShouldBeFalse();
-        vm.DecreaseSpeedCommand.CanExecute(null).ShouldBeFalse();
+            vm.Playback.DecreaseSpeedCommand.Execute(null);
+        vm.Playback.PlaybackSpeed.ShouldBe(0.25);
+        vm.Playback.CanDecreaseSpeed.ShouldBeFalse();
+        vm.Playback.DecreaseSpeedCommand.CanExecute(null).ShouldBeFalse();
     }
 
     [Fact]
     public void ResetSpeed_ReturnsToRealtime()
     {
         var vm = CreateViewModel();
-        vm.PlaybackSpeed = 8.0;
+        vm.Playback.PlaybackSpeed = 8.0;
 
-        vm.ResetSpeedCommand.Execute(null);
+        vm.Playback.ResetSpeedCommand.Execute(null);
 
-        vm.PlaybackSpeed.ShouldBe(1.0);
+        vm.Playback.PlaybackSpeed.ShouldBe(1.0);
     }
 
     [Theory]
@@ -401,9 +401,9 @@ public void PlaybackSpeedText_FormatsCompactly(double speed, string expected)
     {
         var vm = CreateViewModel();
 
-        vm.PlaybackSpeed = speed;
+        vm.Playback.PlaybackSpeed = speed;
 
-        vm.PlaybackSpeedText.ShouldBe(expected);
+        vm.Playback.PlaybackSpeedText.ShouldBe(expected);
     }
 
     [Fact]
@@ -412,11 +412,11 @@ public async Task SpeedShortcuts_StepTheLadder()
         var vm = CreateViewModel();
 
         (await vm.HandleKeyDownAsync(Key.OemPeriod, ModifierKeys.Shift)).ShouldBeTrue();
-        vm.PlaybackSpeed.ShouldBe(1.25);
+        vm.Playback.PlaybackSpeed.ShouldBe(1.25);
 
         (await vm.HandleKeyDownAsync(Key.OemComma, ModifierKeys.Shift)).ShouldBeTrue();
         (await vm.HandleKeyDownAsync(Key.OemComma, ModifierKeys.Shift)).ShouldBeTrue();
-        vm.PlaybackSpeed.ShouldBe(0.75);
+        vm.Playback.PlaybackSpeed.ShouldBe(0.75);
     }
 
     [Fact]
@@ -428,7 +428,7 @@ public async Task SpeedShortcuts_DoNotActBehindAboutPage()
         var handled = await vm.HandleKeyDownAsync(Key.OemPeriod, ModifierKeys.Shift);
 
         handled.ShouldBeFalse();
-        vm.PlaybackSpeed.ShouldBe(1.0);
+        vm.Playback.PlaybackSpeed.ShouldBe(1.0);
     }
 
     [Fact]
@@ -436,7 +436,7 @@ public void ChangingSpeed_FlowsToTheController()
     {
         var vm = CreateViewModelWithController(out var controller, out _);
 
-        vm.PlaybackSpeed = 4.0;
+        vm.Playback.PlaybackSpeed = 4.0;
 
         controller.PlaybackSpeed.ShouldBe(4.0);
     }
diff --git a/SentryDeck.Tests/MainWindowViewModelTests.cs b/SentryDeck.Tests/MainWindowViewModelTests.cs
index a00fbf9..56aea92 100644
--- a/SentryDeck.Tests/MainWindowViewModelTests.cs
+++ b/SentryDeck.Tests/MainWindowViewModelTests.cs
@@ -173,7 +173,7 @@ public void NewViewModel_DefaultsToFrontCamera_AndEmptyOverlay()
         vm.HasNoClipSelected.ShouldBeTrue();
         vm.ShowStatusOverlay.ShouldBeTrue();
         vm.ShowVideoHosts.ShouldBeFalse();
-        vm.PlayPauseIcon.ShouldBe(""); // Segoe Fluent Icons PlaySolid
+        vm.Playback.PlayPauseIcon.ShouldBe(""); // Segoe Fluent Icons PlaySolid
     }
 
     [Theory]
@@ -384,7 +384,7 @@ public void Loading_ShowsStatusOverlay_AndHidesVideo()
     {
         var vm = CreateViewModel();
 
-        vm.IsLoading = true;
+        vm.Playback.IsLoading = true;
 
         vm.ShowStatusOverlay.ShouldBeTrue();
         vm.ShowVideoHosts.ShouldBeFalse();
@@ -419,33 +419,33 @@ public void SelectingClip_HidesOverlay_AndShowsVideo()
     public void CanPlayPause_RequiresClipOrPlayback_AndNotLoading()
     {
         var vm = CreateViewModel();
-        vm.CanPlayPause.ShouldBeFalse();
+        vm.Playback.CanPlayPause.ShouldBeFalse();
 
         vm.SelectedClip = TestClips.Create(1)[0];
-        vm.CanPlayPause.ShouldBeTrue();
+        vm.Playback.CanPlayPause.ShouldBeTrue();
 
-        vm.IsLoading = true;
-        vm.CanPlayPause.ShouldBeFalse();
+        vm.Playback.IsLoading = true;
+        vm.Playback.CanPlayPause.ShouldBeFalse();
 
         // Even with no selected clip, an in-flight playback keeps the toggle live.
-        vm.IsLoading = false;
+        vm.Playback.IsLoading = false;
         vm.SelectedClip = null;
-        vm.IsPlaying = true;
-        vm.CanPlayPause.ShouldBeTrue();
+        vm.Playback.IsPlaying = true;
+        vm.Playback.CanPlayPause.ShouldBeTrue();
     }
 
     [Fact]
     public void CanStop_WhenPlayingOrLoading()
     {
         var vm = CreateViewModel();
-        vm.CanStop.ShouldBeFalse();
+        vm.Playback.CanStop.ShouldBeFalse();
 
-        vm.IsPlaying = true;
-        vm.CanStop.ShouldBeTrue();
+        vm.Playback.IsPlaying = true;
+        vm.Playback.CanStop.ShouldBeTrue();
 
-        vm.IsPlaying = false;
-        vm.IsLoading = true;
-        vm.CanStop.ShouldBeTrue();
+        vm.Playback.IsPlaying = false;
+        vm.Playback.IsLoading = true;
+        vm.Playback.CanStop.ShouldBeTrue();
     }
 
     [Theory]
@@ -455,9 +455,9 @@ public void PlayPauseIcon_ReflectsPlaybackState(bool isPlaying, string expectedI
     {
         var vm = CreateViewModel();
 
-        vm.IsPlaying = isPlaying;
+        vm.Playback.IsPlaying = isPlaying;
 
-        vm.PlayPauseIcon.ShouldBe(expectedIcon);
+        vm.Playback.PlayPauseIcon.ShouldBe(expectedIcon);
     }
 
     [Fact]
diff --git a/SentryDeck/MainWindow.xaml b/SentryDeck/MainWindow.xaml
index 6c6bc21..05895a8 100644
--- a/SentryDeck/MainWindow.xaml
+++ b/SentryDeck/MainWindow.xaml
@@ -141,7 +141,7 @@
                             -->
                             <ItemsControl Focusable="False"
                                           IsHitTestVisible="False"
-                                          ItemsSource="{Binding Data.ChunkBoundaries, Source={StaticResource VmProxy}}">
+                                          ItemsSource="{Binding Data.Playback.ChunkBoundaries, Source={StaticResource VmProxy}}">
                                 <ItemsControl.ItemsPanel>
                                     <ItemsPanelTemplate>
                                         <Grid />
@@ -177,7 +177,7 @@
                             -->
                             <ItemsControl Focusable="False"
                                           IsHitTestVisible="False"
-                                          ItemsSource="{Binding Data.GapPositions, Source={StaticResource VmProxy}}">
+                                          ItemsSource="{Binding Data.Playback.GapPositions, Source={StaticResource VmProxy}}">
                                 <ItemsControl.ItemsPanel>
                                     <ItemsPanelTemplate>
                                         <Grid />
@@ -210,8 +210,8 @@
                                     VerticalAlignment="Center"
                                     CornerRadius="1.5"
                                     IsHitTestVisible="False"
-                                    ToolTip="{Binding Data.EventMarkerTooltip, Source={StaticResource VmProxy}}"
-                                    Visibility="{Binding Data.HasEventMarker, Converter={local:BoolToVisibilityConverter}, Source={StaticResource VmProxy}}">
+                                    ToolTip="{Binding Data.Playback.EventMarkerTooltip, Source={StaticResource VmProxy}}"
+                                    Visibility="{Binding Data.Playback.HasEventMarker, Converter={local:BoolToVisibilityConverter}, Source={StaticResource VmProxy}}">
                                 <Border.Style>
                                     <!--  Reason color via DynamicResource (keyed by ReasonKey) so the marker re-colors on a live OS theme switch.  -->
                                     <Style TargetType="Border">
@@ -238,7 +238,7 @@
                                 </Border.Style>
                                 <Border.Margin>
                                     <MultiBinding Converter="{local:SeekOffsetConverter}">
-                                        <Binding Path="Data.EventMarkerPosition"
+                                        <Binding Path="Data.Playback.EventMarkerPosition"
                                                  Source="{StaticResource VmProxy}" />
                                         <Binding ElementName="SeekRail"
                                                  Path="ActualWidth" />
@@ -768,7 +768,7 @@
                                             <Border.Visibility>
                                                 <MultiBinding Converter="{local:NowPlayingConverter}">
                                                     <Binding />
-                                                    <Binding Path="Data.NowPlayingClip"
+                                                    <Binding Path="Data.Playback.NowPlayingClip"
                                                              Source="{StaticResource VmProxy}" />
                                                 </MultiBinding>
                                             </Border.Visibility>
@@ -1450,21 +1450,21 @@
                         <StackPanel Grid.Column="0"
                                     VerticalAlignment="Center"
                                     Orientation="Horizontal">
-                            <Button Command="{Binding PreviousCommand}"
+                            <Button Command="{Binding Playback.PreviousCommand}"
                                     VerticalAlignment="Center"
                                     AutomationProperties.Name="Previous clip"
-                                    IsEnabled="{Binding CanGoPrevious}"
+                                    IsEnabled="{Binding Playback.CanGoPrevious}"
                                     Style="{StaticResource SubtleIconButton}"
                                     ToolTip="Previous clip (Ctrl+Left)">
                                 <TextBlock Text="&#xE892;"
                                            Style="{StaticResource AppGlyph}" />
                             </Button>
 
-                            <Button Command="{Binding StepFrameBackwardCommand}"
+                            <Button Command="{Binding Playback.StepFrameBackwardCommand}"
                                     Margin="10,0,0,0"
                                     VerticalAlignment="Center"
                                     AutomationProperties.Name="Previous frame"
-                                    IsEnabled="{Binding CanSeek}"
+                                    IsEnabled="{Binding Playback.CanSeek}"
                                     Style="{StaticResource SubtleIconButton}"
                                     ToolTip="Previous frame (,)">
                                 <TextBlock Text="&#xE76B;"
@@ -1472,8 +1472,8 @@
                             </Button>
 
                             <Button x:Name="PlayPauseButton"
-                                    Content="{Binding PlayPauseIcon}"
-                                    Command="{Binding PlayPauseCommand}"
+                                    Content="{Binding Playback.PlayPauseIcon}"
+                                    Command="{Binding Playback.PlayPauseCommand}"
                                     Width="56"
                                     Height="40"
                                     Margin="10,0"
@@ -1481,36 +1481,36 @@
                                     FontFamily="{DynamicResource SymbolThemeFontFamily}"
                                     FontSize="20"
                                     AutomationProperties.Name="Play or pause"
-                                    IsEnabled="{Binding CanPlayPause}"
+                                    IsEnabled="{Binding Playback.CanPlayPause}"
                                     Style="{StaticResource AccentButtonStyle}"
                                     ToolTip="Play/Pause (Space)" />
 
-                            <Button Command="{Binding StepFrameForwardCommand}"
+                            <Button Command="{Binding Playback.StepFrameForwardCommand}"
                                     Margin="0,0,10,0"
                                     VerticalAlignment="Center"
                                     AutomationProperties.Name="Next frame"
-                                    IsEnabled="{Binding CanSeek}"
+                                    IsEnabled="{Binding Playback.CanSeek}"
                                     Style="{StaticResource SubtleIconButton}"
                                     ToolTip="Next frame (.)">
                                 <TextBlock Text="&#xE76C;"
                                            Style="{StaticResource AppGlyph}" />
                             </Button>
 
-                            <Button Command="{Binding NextCommand}"
+                            <Button Command="{Binding Playback.NextCommand}"
                                     VerticalAlignment="Center"
                                     AutomationProperties.Name="Next clip"
-                                    IsEnabled="{Binding CanGoNext}"
+                                    IsEnabled="{Binding Playback.CanGoNext}"
                                     Style="{StaticResource SubtleIconButton}"
                                     ToolTip="Next clip (Ctrl+Right)">
                                 <TextBlock Text="&#xE893;"
                                            Style="{StaticResource AppGlyph}" />
                             </Button>
 
-                            <Button Command="{Binding StopCommand}"
+                            <Button Command="{Binding Playback.StopCommand}"
                                     Margin="10,0,0,0"
                                     VerticalAlignment="Center"
                                     AutomationProperties.Name="Stop"
-                                    IsEnabled="{Binding CanStop}"
+                                    IsEnabled="{Binding Playback.CanStop}"
                                     Style="{StaticResource SubtleIconButton}"
                                     ToolTip="Stop">
                                 <TextBlock Text="&#xE71A;"
@@ -1533,11 +1533,11 @@
                                        Fill="{DynamicResource DividerStrokeColorDefaultBrush}" />
 
                             <!--  Jump straight to the moment the incident happened  -->
-                            <Button Command="{Binding JumpToEventCommand}"
+                            <Button Command="{Binding Playback.JumpToEventCommand}"
                                     Margin="10,0,0,0"
                                     VerticalAlignment="Center"
                                     AutomationProperties.Name="Jump to event"
-                                    IsEnabled="{Binding HasEventMarker}"
+                                    IsEnabled="{Binding Playback.HasEventMarker}"
                                     Style="{StaticResource SubtleIconButton}"
                                     ToolTip="Jump to the moment the event fired (E)">
                                 <StackPanel Orientation="Horizontal">
@@ -1570,25 +1570,25 @@
                                 Margin="16,0"
                                 VerticalAlignment="Center"
                                 AutomationProperties.Name="Seek"
-                                IsEnabled="{Binding CanSeek}"
+                                IsEnabled="{Binding Playback.CanSeek}"
                                 Maximum="1"
                                 Minimum="0"
                                 PreviewMouseDown="SeekSlider_PreviewMouseDown"
                                 PreviewMouseUp="SeekSlider_PreviewMouseUp"
                                 Style="{StaticResource SeekSlider}"
                                 ValueChanged="SeekSlider_ValueChanged"
-                                Value="{Binding SeekPosition, Mode=TwoWay}" />
+                                Value="{Binding Playback.SeekPosition, Mode=TwoWay}" />
 
                         <!--  Time readout  -->
                         <TextBlock Grid.Column="3"
                                    VerticalAlignment="Center"
                                    FontFamily="Consolas"
                                    FontSize="13">
-                            <Run Text="{Binding PositionText, Mode=OneWay}"
+                            <Run Text="{Binding Playback.PositionText, Mode=OneWay}"
                                  Foreground="{DynamicResource TextFillColorPrimaryBrush}" />
                             <Run Text=" / "
                                  Foreground="{DynamicResource TextFillColorTertiaryBrush}" />
-                            <Run Text="{Binding DurationText, Mode=OneWay}"
+                            <Run Text="{Binding Playback.DurationText, Mode=OneWay}"
                                  Foreground="{DynamicResource TextFillColorSecondaryBrush}" />
                         </TextBlock>
 
@@ -1598,7 +1598,7 @@
                                     Margin="16,0,0,0"
                                     VerticalAlignment="Center"
                                     Orientation="Horizontal">
-                            <Button Command="{Binding DecreaseSpeedCommand}"
+                            <Button Command="{Binding Playback.DecreaseSpeedCommand}"
                                     AutomationProperties.Name="Slower"
                                     Style="{StaticResource SubtleIconButton}"
                                     ToolTip="Slower (Shift+,)">
@@ -1607,7 +1607,7 @@
                                            Style="{StaticResource AppGlyph}" />
                             </Button>
                             <Button MinWidth="72"
-                                    Command="{Binding ResetSpeedCommand}"
+                                    Command="{Binding Playback.ResetSpeedCommand}"
                                     AutomationProperties.Name="Playback speed"
                                     Style="{StaticResource SubtleIconButton}"
                                     ToolTip="Playback speed — click to reset to 1x">
@@ -1616,11 +1616,11 @@
                                                FontSize="15"
                                                Foreground="{DynamicResource TextFillColorSecondaryBrush}"
                                                Style="{StaticResource AppGlyphInButton}" />
-                                    <TextBlock Text="{Binding PlaybackSpeedText}"
+                                    <TextBlock Text="{Binding Playback.PlaybackSpeedText}"
                                                VerticalAlignment="Center" />
                                 </StackPanel>
                             </Button>
-                            <Button Command="{Binding IncreaseSpeedCommand}"
+                            <Button Command="{Binding Playback.IncreaseSpeedCommand}"
                                     AutomationProperties.Name="Faster"
                                     Style="{StaticResource SubtleIconButton}"
                                     ToolTip="Faster (Shift+.)">
diff --git a/SentryDeck/MainWindow.xaml.cs b/SentryDeck/MainWindow.xaml.cs
index 182ea4a..a120af9 100644
--- a/SentryDeck/MainWindow.xaml.cs
+++ b/SentryDeck/MainWindow.xaml.cs
@@ -162,19 +162,19 @@ private void ClipListBox_PreviewMouseLeftButtonUp(object sender, MouseButtonEven
 
     private void SeekSlider_PreviewMouseDown(object sender, MouseButtonEventArgs e)
     {
-        _viewModel.BeginSeek();
+        _viewModel.Playback.BeginSeek();
     }
 
     private async void SeekSlider_PreviewMouseUp(object sender, MouseButtonEventArgs e)
     {
-        await _viewModel.EndSeekAsync();
+        await _viewModel.Playback.EndSeekAsync();
     }
 
     // Fires for both thumb-drag and click-then-drag (WPF raises ValueChanged on every Value mutation, whether from dragging the Thumb or from IsMoveToPointEnabled's click-to-position), and also for the one-off value jump a plain click makes.
     // PreviewMouseDown has already called BeginSeek by the time this fires, so even a plain click issues one keyframe scrub seek here, which is harmless since the accurate mouse-up seek runs behind the same serialized lock and lands last.
     private void SeekSlider_ValueChanged(object sender, RoutedPropertyChangedEventArgs<double> e)
     {
-        _viewModel.OnSeekSliderValueChanged();
+        _viewModel.Playback.OnSeekSliderValueChanged();
     }
 
     private void CamerasOnPropertyChanged(object sender, PropertyChangedEventArgs e)
diff --git a/SentryDeck/MainWindowViewModel.cs b/SentryDeck/MainWindowViewModel.cs
index 8717a57..2ed9e02 100644
--- a/SentryDeck/MainWindowViewModel.cs
+++ b/SentryDeck/MainWindowViewModel.cs
@@ -21,24 +21,14 @@ public partial class MainWindowViewModel : ObservableObject
 {
     private readonly List<CamClip> _allClips = [];
     private readonly FlyleafRuntime _flyleafRuntime = new();
-    private readonly Func<VideoPlayerController> _playerControllerFactory;
     private readonly Func<string, IReadOnlyList<CamClip>> _clipLoader;
-    private readonly Func<Task> _backgroundYield;
     private readonly Dispatcher _dispatcher;
-    private readonly Action<Action> _uiInvoker;
     private readonly DispatcherTimer _filterDebounceTimer;
     private readonly IClipExporter _clipExporter;
     private readonly Func<string, string> _savePathPicker;
     private readonly IClipMediaSourceBuilder _exportMediaSourceBuilder;
-    private VideoPlayerController _playerController;
-    private CancellationTokenSource _selectionCts;
-    private readonly SeekScrubCoalescer _scrubCoalescer;
-    private bool _isSeeking;
-
-    // Identifies the current seek gesture.
-    // EndSeekAsync's slow tail (the accurate seek can queue behind in-flight scrubs) may complete after the user has already started a NEW drag; only the completion belonging to the latest gesture may clear _isSeeking, or the position sync would yank the thumb out from under the active drag.
-    private int _seekGeneration;
     private bool _isInitialized;
+    private bool _isDownloadingFFmpeg;
 
     // The source of dashcam roots: auto-discovery by default, or the user's last picked folders.
     // Refresh re-evaluates it to rescan for newly added clips (and, for auto-discovery, newly connected drives).
@@ -60,15 +50,17 @@ public MainWindowViewModel(
         IClipMediaSourceBuilder exportMediaSourceBuilder = null,
         Action<Action> uiInvoker = null)
     {
-        _playerControllerFactory = playerControllerFactory;
         _clipLoader = clipLoader ?? (root => CamStorage.Map(root).Clips);
-        _backgroundYield = backgroundYield ?? (async () => await Dispatcher.Yield(DispatcherPriority.Background));
         _clipExporter = clipExporter ?? new ClipExporter(PackageManager.FindFFmpegDirectory);
         _savePathPicker = savePathPicker ?? PickSavePathWithDialog;
         _exportMediaSourceBuilder = exportMediaSourceBuilder ?? new FfconcatMediaSourceBuilder();
         _dispatcher = Dispatcher.CurrentDispatcher;
-        _uiInvoker = uiInvoker ?? InvokeOnDispatcher;
-        _scrubCoalescer = new SeekScrubCoalescer(ScrubToAsync);
+        Playback = new PlaybackViewModel(
+            playerControllerFactory,
+            backgroundYield ?? (async () => await Dispatcher.Yield(DispatcherPriority.Background)),
+            uiInvoker ?? InvokeOnDispatcher,
+            Error,
+            Cameras);
 
         // Coalesces the expensive clip-list regroup/rebind so fast typing in search stays smooth; the getters stay live, so only the (debounced) change notification is deferred.
         _filterDebounceTimer = new DispatcherTimer(DispatcherPriority.Background, _dispatcher)
@@ -87,6 +79,9 @@ public MainWindowViewModel(
                 OnPropertyChanged(nameof(HasError));
             }
         };
+
+        Playback.PropertyChanged += OnPlaybackPropertyChanged;
+        Playback.CurrentClipChanged += (_, clip) => SelectedClip = clip;
     }
 
     /// <summary>
@@ -109,32 +104,12 @@ public MainWindowViewModel(
     /// </summary>
     public CameraViewsViewModel Cameras { get; } = new();
 
-    public bool ShowMainContent => !ShowAboutPage;
-
     /// <summary>
-    /// Ladder the speed stepper walks: fine increments around 1x, doubling above.
-    /// Flyleaf clamps Player.Speed to [0.125, 16], so 16x is the hard ceiling.
+    /// The player: loading the selected clip, transport, the seek bar and its markers, and speed.
     /// </summary>
-    public static IReadOnlyList<double> PlaybackSpeedSteps { get; } =
-    [
-        0.25,
-        0.5,
-        0.75,
-        1.0,
-        1.25,
-        1.5,
-        2.0,
-        4.0,
-        8.0,
-        16.0,
-    ];
-
-    /// <summary>Speed readout shown on the stepper, e.g. "1x" or "0.25x".</summary>
-    public string PlaybackSpeedText => $"{PlaybackSpeed:0.##}x";
-
-    public bool CanIncreaseSpeed => PlaybackSpeed < PlaybackSpeedSteps[^1];
-
-    public bool CanDecreaseSpeed => PlaybackSpeed > PlaybackSpeedSteps[0];
+    public PlaybackViewModel Playback { get; }
+
+    public bool ShowMainContent => !ShowAboutPage;
 
     public IReadOnlyList<CamClip> FilteredClips => _allClips
         .Where(MatchesFilter)
@@ -177,68 +152,21 @@ private void OnFilterDebounceTick(object sender, EventArgs e)
         OnPropertyChanged(nameof(ClipCount));
     }
 
-    public string PositionText
-    {
-        get
-        {
-            var duration = _playerController?.Duration ?? TimeSpan.Zero;
-            var position = TimeSpan.FromSeconds(SeekPosition * duration.TotalSeconds);
-            return FormatTimeSpan(position);
-        }
-    }
-
-    public string DurationText => FormatTimeSpan(_playerController?.Duration ?? TimeSpan.Zero);
-
-    public bool CanSeek => _playerController?.IsMediaOpen == true && !IsLoading && _playerController.Duration > TimeSpan.Zero;
-
-    public bool CanPlayPause => (SelectedClip is not null || IsPlaying) && !IsLoading;
-
-    public bool CanStop => IsPlaying || IsLoading;
-
-    public bool CanGoNext => _playerController?.CanGoNext == true;
-
-    public bool CanGoPrevious => _playerController?.CanGoPrevious == true;
-
-    // Segoe Fluent Icons: Pause (E769) / PlaySolid (F5B0).
-    // Rendered with SymbolThemeFontFamily.
-    public string PlayPauseIcon => IsPlaying ? "" : "";
-
     // The full-screen overlay only covers the no-video states (scanning with no clip, error, empty); as a WPF sibling it can't draw over the Flyleaf video surface anyway.
     // While a selected clip loads, the hosts stay visible and simply show black until the first frame decodes, with no loading screen flashing mid-playback.
     public bool ShowStatusOverlay => (IsLoading && SelectedClip is null) || Error.IsVisible || HasNoClipSelected;
 
+    /// <summary>
+    /// True while anything blocks the video pane: a clip scan, the FFmpeg download, or the selected clip loading.
+    /// </summary>
+    public bool IsLoading => IsLoadingClips || _isDownloadingFFmpeg || Playback.IsLoading;
+
     public bool ShowVideoHosts => SelectedClip is not null && !Error.IsVisible;
 
     public bool HasError => Error.IsVisible;
 
     public bool HasNoClipSelected => SelectedClip is null && !IsLoading && !Error.IsVisible;
 
-    // --- Seek-bar overlays for the selected clip (event moment + chunk seams + gaps) ---
-    // Recomputed whenever the selection changes or the controller opens/replaces its media source; plain fields (not ObservableProperty) because they're derived, not independently settable.
-    private double? _eventPosition;
-    private IReadOnlyList<double> _chunkBoundaries = [];
-    private IReadOnlyList<double> _gapPositions = [];
-
-    /// <summary>The event moment as a 0..1 fraction of the clip timeline (0 when none; pair with <see cref="HasEventMarker"/>).</summary>
-    public double EventMarkerPosition => _eventPosition ?? 0d;
-
-    /// <summary>True when the selected clip has a locatable event moment to mark on the seek bar and jump to.</summary>
-    public bool HasEventMarker => _eventPosition.HasValue;
-
-    /// <summary>Friendly reason + time for the event marker tooltip, e.g. "Honk · 3:53 PM".</summary>
-    public string EventMarkerTooltip => SelectedClip?.Event is { } camEvent && HasEventMarker
-        ? $"{ClipDisplay.ReasonLabel(camEvent)} · {camEvent.Timestamp:t}"
-        : string.Empty;
-
-    /// <summary>Interior chunk-boundary fractions (i/Count for i in 1..Count-1); empty for fewer than two chunks.</summary>
-    public IReadOnlyList<double> ChunkBoundaries => _chunkBoundaries;
-
-    /// <summary>
-    /// Fractional seek-bar positions where the opened clip's media time skips over a wall-clock gap (deleted/corrupt/excluded chunks, or a Sentry idle period).
-    /// Empty until the selected clip's media source has actually been built and opened by the controller.
-    /// </summary>
-    public IReadOnlyList<double> GapPositions => _gapPositions;
-
     // --- Export selection (in/out marks on the seek bar, as 0..1 fractions like SeekPosition) ---
     // Plain fields + an explicit notify helper (not ObservableProperty) because the pair changes together under shared invariants (start < end) and several derived properties hang off both.
     private double? _selectionStart;
@@ -260,7 +188,7 @@ public string PositionText
     /// <summary>True when both marks are set (a complete, exportable range).</summary>
     public bool HasSelection => _selectionStart.HasValue && _selectionEnd.HasValue;
 
-    public bool CanExportSelection => HasSelection && !IsExporting && CanSeek;
+    public bool CanExportSelection => HasSelection && !IsExporting && Playback.CanSeek;
 
     /// <summary>
     /// True while the trim panel is open.
@@ -305,7 +233,7 @@ public string SelectionDurationText
                 return string.Empty;
             }
 
-            var duration = _playerController?.Duration ?? TimeSpan.Zero;
+            var duration = Playback.Duration;
             return FormatTimeSpan(TimeSpan.FromSeconds((end - start) * duration.TotalSeconds));
         }
     }
@@ -325,58 +253,22 @@ public string SelectionDurationText
     [NotifyPropertyChangedFor(nameof(HasNoClipSelected))]
     [NotifyPropertyChangedFor(nameof(ShowStatusOverlay))]
     [NotifyPropertyChangedFor(nameof(ShowVideoHosts))]
-    [NotifyPropertyChangedFor(nameof(CanPlayPause))]
     private CamClip _selectedClip;
 
-    // The clip actually loaded in the player (drives the now-playing marker in the list).
-    // Distinct from SelectedClip so a marker can persist even when selection is elsewhere.
-    [ObservableProperty]
-    private CamClip _nowPlayingClip;
-
     [ObservableProperty]
     [NotifyPropertyChangedFor(nameof(ShowMainContent))]
     private bool _showAboutPage;
 
+    // True while the clip list is being (re)scanned from disk; drives the sidebar loading indicator.
     [ObservableProperty]
-    [NotifyPropertyChangedFor(nameof(CanPlayPause))]
-    [NotifyPropertyChangedFor(nameof(CanStop))]
+    [NotifyPropertyChangedFor(nameof(IsLoading))]
     [NotifyPropertyChangedFor(nameof(ShowStatusOverlay))]
     [NotifyPropertyChangedFor(nameof(ShowVideoHosts))]
     [NotifyPropertyChangedFor(nameof(HasNoClipSelected))]
-    [NotifyPropertyChangedFor(nameof(CanSeek))]
-    [NotifyPropertyChangedFor(nameof(CanExportSelection))]
-    [NotifyCanExecuteChangedFor(nameof(StepFrameBackwardCommand))]
-    [NotifyCanExecuteChangedFor(nameof(StepFrameForwardCommand))]
-    [NotifyCanExecuteChangedFor(nameof(MarkSelectionStartCommand))]
-    [NotifyCanExecuteChangedFor(nameof(MarkSelectionEndCommand))]
-    [NotifyCanExecuteChangedFor(nameof(ToggleTrimmingCommand))]
-    [NotifyCanExecuteChangedFor(nameof(ExportSelectionCommand))]
-    private bool _isLoading;
-
-    // True while the clip list is being (re)scanned from disk; drives the sidebar loading indicator.
-    [ObservableProperty]
     [NotifyCanExecuteChangedFor(nameof(RefreshClipsCommand))]
     [NotifyCanExecuteChangedFor(nameof(OpenFolderCommand))]
     private bool _isLoadingClips;
 
-    [ObservableProperty]
-    [NotifyPropertyChangedFor(nameof(PositionText))]
-    private double _seekPosition;
-
-    [ObservableProperty]
-    [NotifyPropertyChangedFor(nameof(PlayPauseIcon))]
-    [NotifyPropertyChangedFor(nameof(CanPlayPause))]
-    [NotifyPropertyChangedFor(nameof(CanStop))]
-    private bool _isPlaying;
-
-    [ObservableProperty]
-    [NotifyPropertyChangedFor(nameof(PlaybackSpeedText))]
-    [NotifyPropertyChangedFor(nameof(CanIncreaseSpeed))]
-    [NotifyPropertyChangedFor(nameof(CanDecreaseSpeed))]
-    [NotifyCanExecuteChangedFor(nameof(IncreaseSpeedCommand))]
-    [NotifyCanExecuteChangedFor(nameof(DecreaseSpeedCommand))]
-    private double _playbackSpeed = 1.0;
-
     public async Task InitializeAsync()
     {
         if (_isInitialized)
@@ -405,36 +297,16 @@ public async Task InitializeAsync()
     public void Shutdown()
     {
         _filterDebounceTimer.Stop();
-        _selectionCts?.Cancel();
-        _selectionCts?.Dispose();
-        _selectionCts = null;
-
-        var controller = _playerController;
-        _playerController = null;
-
-        if (controller is null)
-            return;
-
-        controller.PropertyChanged -= PlayerControllerOnPropertyChanged;
-        controller.Dispose();
+        Playback.Shutdown();
     }
 
-    public void InitializePlayer()
-    {
-        if (_playerController is not null)
-            return;
-
-        _playerController = _playerControllerFactory();
-        _playerController.PropertyChanged += PlayerControllerOnPropertyChanged;
-        _playerController.PlaybackSpeed = PlaybackSpeed;
-    }
+    public void InitializePlayer() => Playback.InitializePlayer();
 
     public async Task LoadClipsAsync(IEnumerable<string> roots, TimeSpan minimumLoadingDuration = default)
     {
         Error.Clear();
         _allClips.Clear();
         SelectedClip = null;
-        IsLoading = true;
         IsLoadingClips = true;
 
         // Clear the list right away so a (re)scan visibly empties it and shows the loading bar before refilling.
@@ -466,7 +338,7 @@ public async Task LoadClipsAsync(IEnumerable<string> roots, TimeSpan minimumLoad
                 }
             }
 
-            _playerController?.LoadClips(_allClips);
+            Playback.SetPlaylist(_allClips);
 
             // Hold the loading state briefly so a fast rescan still reads as a deliberate refresh (clear -> loading -> refill) instead of an imperceptible flicker.
             var remaining = minimumLoadingDuration - stopwatch.Elapsed;
@@ -477,7 +349,6 @@ public async Task LoadClipsAsync(IEnumerable<string> roots, TimeSpan minimumLoad
         }
         finally
         {
-            IsLoading = false;
             IsLoadingClips = false;
             OnPropertyChanged(nameof(FilteredClips));
             OnPropertyChanged(nameof(ClipCount));
@@ -546,9 +417,6 @@ private void RefreshClipState()
         OnPropertyChanged(nameof(HasNoClipSelected));
         OnPropertyChanged(nameof(ShowStatusOverlay));
         OnPropertyChanged(nameof(ShowVideoHosts));
-        OnPropertyChanged(nameof(CanPlayPause));
-        OnPropertyChanged(nameof(CanGoNext));
-        OnPropertyChanged(nameof(CanGoPrevious));
     }
 
     // Gated like Refresh: LoadClipsAsync has no re-entrancy protection, so picking a folder while a scan is still running would interleave two loads and merge both roots into one clip list.
@@ -571,10 +439,7 @@ private async Task OpenFolderAsync()
                 folders.Length,
                 folders);
 
-            if (_playerController is not null)
-            {
-                await _playerController.StopAsync();
-            }
+            await Playback.StopPlayerAsync();
 
             _rootSource = () => folders;
             await LoadClipsAsync(folders);
@@ -590,69 +455,12 @@ private async Task RefreshClipsAsync()
     {
         Log.Debug("Refreshing clips");
 
-        if (_playerController is not null)
-        {
-            await _playerController.StopAsync();
-        }
-
+        await Playback.StopPlayerAsync();
         await LoadClipsAsync(_rootSource(), TimeSpan.FromMilliseconds(400));
     }
 
     private bool CanRefreshClips => !IsLoadingClips;
 
-    [RelayCommand]
-    private async Task PlayPauseAsync()
-    {
-        if (_playerController is not null)
-        {
-            await _playerController.TogglePlayPauseAsync();
-        }
-    }
-
-    [RelayCommand]
-    private async Task StopAsync()
-    {
-        if (_playerController is null)
-            return;
-
-        // A selection that is still waiting to load would otherwise start playing right after the stop.
-        _selectionCts?.Cancel();
-
-        await _playerController.StopAsync();
-        IsLoading = false;
-        SeekPosition = 0;
-        NowPlayingClip = null;
-    }
-
-    [RelayCommand(CanExecute = nameof(CanSeek))]
-    private async Task StepFrameBackwardAsync()
-    {
-        if (_playerController is not null)
-        {
-            await _playerController.StepFrameAsync(forward: false);
-        }
-    }
-
-    [RelayCommand(CanExecute = nameof(CanSeek))]
-    private async Task StepFrameForwardAsync()
-    {
-        if (_playerController is not null)
-        {
-            await _playerController.StepFrameAsync(forward: true);
-        }
-    }
-
-    [RelayCommand(CanExecute = nameof(HasEventMarker))]
-    private async Task JumpToEventAsync()
-    {
-        if (!HasEventMarker)
-            return;
-
-        Log.Debug("Jumping to event moment. Position={EventMarkerPosition}", EventMarkerPosition);
-        SeekPosition = EventMarkerPosition;
-        await SeekToCurrentPositionAsync();
-    }
-
     /// <summary>
     /// Marks the selection start at the current playhead.
     /// A mark that would invert the range (start at or past the existing end) clears the other mark instead of silently swapping.
@@ -661,8 +469,8 @@ private async Task JumpToEventAsync()
     private void MarkSelectionStart()
     {
         IsTrimming = true;
-        _selectionStart = SeekPosition;
-        if (_selectionEnd is { } end && end <= SeekPosition)
+        _selectionStart = Playback.SeekPosition;
+        if (_selectionEnd is { } end && end <= Playback.SeekPosition)
         {
             _selectionEnd = null;
         }
@@ -675,8 +483,8 @@ private void MarkSelectionStart()
     private void MarkSelectionEnd()
     {
         IsTrimming = true;
-        _selectionEnd = SeekPosition;
-        if (_selectionStart is { } start && start >= SeekPosition)
+        _selectionEnd = Playback.SeekPosition;
+        if (_selectionStart is { } start && start >= Playback.SeekPosition)
         {
             _selectionStart = null;
         }
@@ -720,15 +528,15 @@ private void CancelTrim()
     /// <summary>True when either mark is set (drives the clear affordance).</summary>
     public bool HasAnySelectionMark => _selectionStart.HasValue || _selectionEnd.HasValue;
 
-    // Everything downstream of CanSeek: the mark/export commands gate on it alongside the frame-step commands.
+    // The trim commands gate on the player being seekable.
+    private bool CanSeek => Playback.CanSeek;
+
+    // Everything downstream of CanSeek: the mark/export commands gate on it.
     private void NotifyCanSeekChanged()
     {
-        OnPropertyChanged(nameof(CanSeek));
         OnPropertyChanged(nameof(CanExportSelection));
         OnPropertyChanged(nameof(SelectionDurationText)); // scales with Duration
         OnPropertyChanged(nameof(TrimHintText));
-        StepFrameBackwardCommand.NotifyCanExecuteChanged();
-        StepFrameForwardCommand.NotifyCanExecuteChanged();
         MarkSelectionStartCommand.NotifyCanExecuteChanged();
         MarkSelectionEndCommand.NotifyCanExecuteChanged();
         ToggleTrimmingCommand.NotifyCanExecuteChanged();
@@ -753,8 +561,8 @@ private void NotifySelectionChanged()
     [RelayCommand(CanExecute = nameof(CanExportSelection))]
     private async Task ExportSelectionAsync()
     {
-        var clip = _playerController?.CurrentClip;
-        var mediaSource = _playerController?.OpenedMediaSource;
+        var clip = Playback.CurrentClip;
+        var mediaSource = Playback.OpenedMediaSource;
         if (clip is null || mediaSource is null || mediaSource.Duration <= TimeSpan.Zero
             || _selectionStart is not { } startFraction || _selectionEnd is not { } endFraction)
         {
@@ -784,7 +592,7 @@ private async Task SaveEventClipAsync(CamClip clip)
         ClipMediaSource mediaSource;
         try
         {
-            mediaSource = _playerController?.CurrentClip == clip ? _playerController.OpenedMediaSource : null;
+            mediaSource = Playback.CurrentClip == clip ? Playback.OpenedMediaSource : null;
 
             // Building an unopened clip's source does real IO (probe every chunk, write ffconcat files) and can throw (drive unplugged, temp write fails).
             // Unlike ExportSelectionAsync, nothing downstream caught it, so the fault escaped to the dispatcher; surface a normal "Export Failed" dialog instead.
@@ -907,30 +715,10 @@ private static string SanitizeFileName(string name)
         return name;
     }
 
-    [RelayCommand]
-    private async Task PreviousAsync()
-    {
-        if (_playerController is null)
-            return;
-
-        await _playerController.PreviousAsync();
-        SelectedClip = _playerController.CurrentClip;
-    }
-
-    [RelayCommand]
-    private async Task NextAsync()
-    {
-        if (_playerController is null)
-            return;
-
-        await _playerController.NextAsync();
-        SelectedClip = _playerController.CurrentClip;
-    }
-
     [RelayCommand]
     private async Task DownloadFFmpegAsync()
     {
-        IsLoading = true;
+        SetDownloadingFFmpeg(true);
         Error.Clear();
 
         try
@@ -955,65 +743,17 @@ private async Task DownloadFFmpegAsync()
         }
         finally
         {
-            IsLoading = false;
+            SetDownloadingFFmpeg(false);
         }
     }
 
-    private async Task PlaySelectedClipAsync(CamClip clip, CancellationToken cancellationToken)
+    private void SetDownloadingFFmpeg(bool value)
     {
-        if (clip is null || _playerController is null)
-            return;
-
-        Error.Clear();
-        IsLoading = true;
-        await _backgroundYield();
-
-        // A newer selection superseded this one while we yielded, so drop it and let the latest win and the selection doesn't rubber-band backwards as earlier, slower loads complete.
-        if (cancellationToken.IsCancellationRequested || !ReferenceEquals(clip, SelectedClip))
-        {
-            // A newer selection's own load owns IsLoading now, but if the selection was cleared outright (deselect, or a filter dropping the clip), no load is in flight and nothing else ever resets the flag, leaving a permanent "Loading…" overlay over the video pane.
-            if (SelectedClip is null)
-            {
-                IsLoading = false;
-            }
-
-            return;
-        }
-
-        try
-        {
-            await _playerController.GoToClipAsync(clip);
-
-            if (cancellationToken.IsCancellationRequested)
-                return;
-
-            // Auto-focus the camera that triggered the event (Full metadata mode).
-            if (clip.Event is not null)
-            {
-                Cameras.SelectedCameraView = Cameras.CameraIdToView(clip.Event.Camera);
-            }
-        }
-        catch (Exception ex)
-        {
-            if (cancellationToken.IsCancellationRequested)
-            {
-                // Same stuck-overlay guard as the pre-load early-return above.
-                if (SelectedClip is null)
-                {
-                    IsLoading = false;
-                }
-
-                return;
-            }
-
-            IsLoading = false;
-            Log.Error(
-                ex,
-                "Failed to play selected clip. ClipName={ClipName}; ClipPath={ClipPath}",
-                clip.Name,
-                clip.FullPath);
-            Error.Show("Playback Failed", $"Could not play clip: {clip.Name}\n\nError: {ex.Message}");
-        }
+        _isDownloadingFFmpeg = value;
+        OnPropertyChanged(nameof(IsLoading));
+        OnPropertyChanged(nameof(ShowStatusOverlay));
+        OnPropertyChanged(nameof(ShowVideoHosts));
+        OnPropertyChanged(nameof(HasNoClipSelected));
     }
 
     /// <summary>
@@ -1110,9 +850,9 @@ private Func<Task> ResolveKeyAction(Key key, ModifierKeys modifiers)
                 return Run(() => Cameras.SelectCameraViewCommand.Execute(numberedOption.ViewId));
             }
 
-            if (key == Key.E && HasEventMarker)
+            if (key == Key.E && Playback.HasEventMarker)
             {
-                return JumpToEventAsync;
+                return () => Playback.JumpToEventCommand.ExecuteAsync(null);
             }
 
             if (key == Key.I && CanSeek)
@@ -1142,30 +882,29 @@ private Func<Task> ResolveKeyAction(Key key, ModifierKeys modifiers)
         {
             if (key == Key.OemComma)
             {
-                return Run(DecreaseSpeed);
+                return Run(() => Playback.DecreaseSpeedCommand.Execute(null));
             }
 
             if (key == Key.OemPeriod)
             {
-                return Run(IncreaseSpeed);
+                return Run(() => Playback.IncreaseSpeedCommand.Execute(null));
             }
         }
 
-        var controller = _playerController;
-        if (controller is null)
+        if (!Playback.HasPlayer)
         {
             return null;
         }
 
         return key switch
         {
-            Key.Space => controller.TogglePlayPauseAsync,
-            Key.OemComma when modifiers == ModifierKeys.None && CanSeek => () => controller.StepFrameAsync(forward: false),
-            Key.OemPeriod when modifiers == ModifierKeys.None && CanSeek => () => controller.StepFrameAsync(forward: true),
-            Key.Left when modifiers == ModifierKeys.Control => CanGoPrevious ? PreviousAsync : Run(() => { }),
-            Key.Right when modifiers == ModifierKeys.Control => CanGoNext ? NextAsync : Run(() => { }),
-            Key.Left => () => SeekRelativeAsync(TimeSpan.FromSeconds(-5)),
-            Key.Right => () => SeekRelativeAsync(TimeSpan.FromSeconds(5)),
+            Key.Space => Playback.TogglePlayPauseAsync,
+            Key.OemComma when modifiers == ModifierKeys.None && CanSeek => () => Playback.StepFrameAsync(forward: false),
+            Key.OemPeriod when modifiers == ModifierKeys.None && CanSeek => () => Playback.StepFrameAsync(forward: true),
+            Key.Left when modifiers == ModifierKeys.Control => Playback.CanGoPrevious ? () => Playback.PreviousCommand.ExecuteAsync(null) : Run(() => { }),
+            Key.Right when modifiers == ModifierKeys.Control => Playback.CanGoNext ? () => Playback.NextCommand.ExecuteAsync(null) : Run(() => { }),
+            Key.Left => () => Playback.SeekRelativeAsync(TimeSpan.FromSeconds(-5)),
+            Key.Right => () => Playback.SeekRelativeAsync(TimeSpan.FromSeconds(5)),
             _ => null,
         };
 
@@ -1176,259 +915,34 @@ static Func<Task> Run(Action action) => () =>
         };
     }
 
-    private Task SeekRelativeAsync(TimeSpan offset)
-    {
-        if (_playerController is not { } controller || !CanSeek)
-        {
-            return Task.CompletedTask;
-        }
-
-        return controller.SeekByAsync(offset);
-    }
-
-    public void BeginSeek()
-    {
-        if (CanSeek)
-        {
-            _seekGeneration++;
-            _isSeeking = true;
-            _scrubCoalescer.Reset();
-
-            // Holds playback paused for the gesture, so each scrub is one cheap paused seek and the release resumes every camera together.
-            // The controller serializes this ahead of the first scrub seek, so it needs no await here.
-            _ = _playerController.BeginScrubAsync();
-        }
-    }
-
-    public async Task EndSeekAsync()
-    {
-        var generation = _seekGeneration;
-
-        if (_playerController is null || !CanSeek)
-        {
-            _isSeeking = false;
-            return;
-        }
-
-        // The gesture is over: drop any scrub value still queued in the coalescer.
-        // When the in-flight scrub completes it would otherwise re-issue that value as a keyframe seek AFTER the accurate seek below (both queue on the controller's serialized-operation lock in that order), leaving the playhead on a keyframe instead of the release point.
-        _scrubCoalescer.CancelPending();
-
-        // _isSeeking stays true until the release seek completes, so the position sync can't pull the thumb back while a scrub seek winds down.
-        // The release seek queues behind any in-flight scrub on the controller's serialized-operation lock, so it always lands last.
-        await _playerController.EndScrubAsync(CurrentSeekTargetPosition());
-
-        // Only the latest gesture's completion may end the seeking state: if the user has already grabbed the thumb again, this completion is stale and their new drag owns the flag.
-        if (generation == _seekGeneration)
-        {
-            _isSeeking = false;
-        }
-    }
-
-    /// <summary>
-    /// Called on every seek-bar value change.
-    /// While a seek gesture is active (<see cref="_isSeeking"/>, set by <see cref="BeginSeek"/> on mouse-down for clicks and drags alike), each value feeds the scrub coalescer so the video follows the thumb in near-real-time.
-    /// A plain click therefore issues one scrub seek too; the accurate seek from <see cref="EndSeekAsync"/> runs behind the same serialized lock and always lands last.
-    /// Value changes from playback position sync arrive with <see cref="_isSeeking"/> false and are ignored.
-    /// </summary>
-    public void OnSeekSliderValueChanged()
-    {
-        if (!_isSeeking)
-            return;
-
-        OnPropertyChanged(nameof(PositionText));
-
-        if (CanSeek)
-        {
-            _scrubCoalescer.OnDragValueChanged(CurrentSeekTargetPosition());
-        }
-    }
-
-    private async Task SeekToCurrentPositionAsync()
-    {
-        if (_playerController is null)
-            return;
-
-        var duration = _playerController.Duration;
-        if (duration.TotalSeconds > 0)
-        {
-            await _playerController.SeekAsync(CurrentSeekTargetPosition());
-        }
-    }
-
-    private Task ScrubToAsync(TimeSpan position) =>
-        _playerController?.ScrubSeekAsync(position) ?? Task.CompletedTask;
-
-    private TimeSpan CurrentSeekTargetPosition()
-    {
-        var duration = _playerController?.Duration ?? TimeSpan.Zero;
-        return TimeSpan.FromSeconds(SeekPosition * duration.TotalSeconds);
-    }
+    private static string FormatTimeSpan(TimeSpan ts) => PlaybackViewModel.FormatTimeSpan(ts);
 
-    // Derives the seek-bar overlays for the selected clip: the event moment, the interior chunk-boundary ticks, and gap ticks (mapped onto the 0..1 seek axis).
-    // Nulls out cleanly when the selection is cleared or the clip has no usable event metadata.
-    //
-    // Prefers the controller's actually-opened ClipMediaSource when it belongs to this clip: that source has real probed durations and gap-aware wall-clock mapping (see ClipMediaSource.ToMediaTime), so its positions match what's actually playing.
-    // Selecting a clip is synchronous but opening its media is not, so immediately after selection (or for a clip that never opens, e.g. in tests with no controller) there is no opened source yet; a ClipTimeline estimate (uniform assumed chunk length) is used as a same-frame placeholder so the markers don't flash empty, and is superseded once OpenedMediaSource changes.
-    private void RecomputeSelectedClipTimeline()
+    private void OnPlaybackPropertyChanged(object sender, PropertyChangedEventArgs e)
     {
-        var clip = SelectedClip;
-        if (clip is null)
-        {
-            _eventPosition = null;
-            _chunkBoundaries = [];
-            _gapPositions = [];
-            return;
-        }
-
-        var mediaSource = _playerController?.CurrentClip == clip ? _playerController?.OpenedMediaSource : null;
-
-        if (mediaSource is not null && mediaSource.Duration > TimeSpan.Zero)
-        {
-            RecomputeFromMediaSource(clip, mediaSource);
-        }
-        else
+        switch (e.PropertyName)
         {
-            RecomputeFromEstimatedTimeline(clip);
-        }
-    }
-
-    private void RecomputeFromMediaSource(CamClip clip, ClipMediaSource mediaSource)
-    {
-        var durationSeconds = mediaSource.Duration.TotalSeconds;
-
-        _chunkBoundaries = mediaSource.ChunkStarts.Count < 2
-            ? []
-            : mediaSource.ChunkStarts.Skip(1).Select(start => start.TotalSeconds / durationSeconds).ToList();
-
-        _gapPositions = mediaSource.GapPositions
-            .Select(position => position.TotalSeconds / durationSeconds)
-            .ToList();
-
-        var camEvent = clip.Event;
-        if (camEvent is null || camEvent.Timestamp == default)
-        {
-            _eventPosition = null;
-            return;
-        }
-
-        // Fraction 0 is a real position: an event that fired on the first recorded frame (or one snapped forward to the start of the footage) still deserves its marker.
-        var mediaTime = mediaSource.ToMediaTime(camEvent.Timestamp);
-        var fraction = mediaTime?.TotalSeconds / durationSeconds;
-        _eventPosition = fraction is >= 0 and <= 1 ? fraction : null;
-    }
-
-    // Fallback used before the selected clip's media has actually been opened (or when it never will be, e.g. no controller in tests): the legacy uniform-chunk-length estimate.
-    // Carries no gap information, since gaps can only be known once the builder has probed real durations.
-    private void RecomputeFromEstimatedTimeline(CamClip clip)
-    {
-        var timeline = new ClipTimeline(clip.Chunks);
-        _chunkBoundaries = timeline.Count < 2
-            ? []
-            : Enumerable.Range(1, timeline.Count - 1).Select(i => (double)i / timeline.Count).ToList();
-        _gapPositions = [];
-
-        var camEvent = clip.Event;
-        if (camEvent is null || camEvent.Timestamp == default || clip.Chunks.Count == 0 || timeline.Duration <= TimeSpan.Zero)
-        {
-            _eventPosition = null;
-            return;
-        }
-
-        // The event landing at or after the start and no later than the modeled end is markable (exactly 0 = the event fired on the first recorded frame); clock skew (fraction < 0) or an event past the estimate (> 1) yields no marker.
-        var fraction = (camEvent.Timestamp - clip.Chunks[0].Timestamp).TotalSeconds / timeline.Duration.TotalSeconds;
-        _eventPosition = fraction is >= 0 and <= 1 ? fraction : null;
-    }
-
-    private void UpdateSeekPositionFromController()
-    {
-        if (_playerController is null || _isSeeking)
-            return;
-
-        var duration = _playerController.Duration;
-        SeekPosition = duration.TotalSeconds > 0
-            ? Math.Clamp(_playerController.Position.TotalSeconds / duration.TotalSeconds, 0, 1)
-            : 0;
-    }
-
-    private void PlayerControllerOnPropertyChanged(object sender, PropertyChangedEventArgs e)
-    {
-        if (string.IsNullOrWhiteSpace(e.PropertyName))
-            return;
-
-        RunOnUiThread(() => HandlePlayerControllerPropertyChanged(e.PropertyName));
-    }
-
-    private void HandlePlayerControllerPropertyChanged(string propertyName)
-    {
-        if (_playerController is null)
-            return;
-
-        switch (propertyName)
-        {
-            case nameof(VideoPlayerController.IsLoading):
-                IsLoading = _playerController.IsLoading;
-                break;
-
-            case nameof(VideoPlayerController.IsPlaying):
-                IsPlaying = _playerController.IsPlaying;
+            case nameof(PlaybackViewModel.IsLoading):
+                OnPropertyChanged(nameof(IsLoading));
+                OnPropertyChanged(nameof(ShowStatusOverlay));
+                OnPropertyChanged(nameof(ShowVideoHosts));
+                OnPropertyChanged(nameof(HasNoClipSelected));
                 break;
 
-            case nameof(VideoPlayerController.Duration):
-                UpdateSeekPositionFromController();
-                OnPropertyChanged(nameof(DurationText));
-                OnPropertyChanged(nameof(PositionText));
+            case nameof(PlaybackViewModel.CanSeek):
                 NotifyCanSeekChanged();
                 break;
 
-            case nameof(VideoPlayerController.Position):
-                UpdateSeekPositionFromController();
-                break;
-
-            case nameof(VideoPlayerController.OpenedMediaSource):
-                // The controller finished (re)building the media source for the selected clip (or one under recovery from a corrupt chunk) -- refresh the gap-aware overlays now that real probed durations/timestamps are available.
+            case nameof(PlaybackViewModel.OpenedMediaSource):
                 // A rebuild can reshape the timeline (chunks excluded during recovery), so in/out fractions marked against the old timeline no longer point at the same footage.
                 if (HasAnySelectionMark)
                 {
                     ClearSelection();
                 }
 
-                RecomputeSelectedClipTimeline();
-                OnPropertyChanged(nameof(EventMarkerPosition));
-                OnPropertyChanged(nameof(HasEventMarker));
-                OnPropertyChanged(nameof(EventMarkerTooltip));
-                OnPropertyChanged(nameof(ChunkBoundaries));
-                OnPropertyChanged(nameof(GapPositions));
-                JumpToEventCommand.NotifyCanExecuteChanged();
-                break;
-
-            case nameof(VideoPlayerController.ErrorMessage):
-                if (_playerController.ErrorMessage is not null)
-                {
-                    Error.Show("Playback Error", _playerController.ErrorMessage);
-                }
-
-                break;
-
-            case nameof(VideoPlayerController.CurrentClip):
-                SelectedClip = _playerController.CurrentClip;
-                NowPlayingClip = _playerController.CurrentClip;
-                RefreshClipState();
-                break;
-
-            case nameof(VideoPlayerController.IsMediaOpen):
-                NotifyCanSeekChanged();
                 break;
         }
     }
 
-    internal static string FormatTimeSpan(TimeSpan ts)
-    {
-        return ts.TotalHours >= 1
-            ? ts.ToString(@"h\:mm\:ss")
-            : ts.ToString(@"m\:ss");
-    }
-
     private void ShowFFmpegMissingError()
     {
         Log.Debug("Showing FFmpeg missing prompt");
@@ -1515,12 +1029,12 @@ private async Task DeleteClipAsync(CamClip clip)
 
         // Flyleaf keeps the current clip's camera files open; Windows can't recycle a folder whose files are still locked, so stop and close the players before deleting it.
         var isCurrent = ReferenceEquals(SelectedClip, clip)
-            || ReferenceEquals(NowPlayingClip, clip)
-            || _playerController?.CurrentClip == clip;
-        if (isCurrent && _playerController is not null)
+            || ReferenceEquals(Playback.NowPlayingClip, clip)
+            || Playback.CurrentClip == clip;
+        if (isCurrent && Playback.HasPlayer)
         {
-            await _playerController.StopAsync();
-            SeekPosition = 0;
+            await Playback.StopPlayerAsync();
+            Playback.SeekPosition = 0;
         }
 
         try
@@ -1537,11 +1051,11 @@ private async Task DeleteClipAsync(CamClip clip)
 
         // Drop it from the sidebar list and keep the player's Next/Previous playlist in sync.
         _allClips.Remove(clip);
-        _playerController?.RemoveClip(clip);
+        Playback.RemoveFromPlaylist(clip);
 
-        if (ReferenceEquals(NowPlayingClip, clip))
+        if (ReferenceEquals(Playback.NowPlayingClip, clip))
         {
-            NowPlayingClip = null;
+            Playback.NowPlayingClip = null;
         }
 
         if (ReferenceEquals(SelectedClip, clip))
@@ -1569,8 +1083,6 @@ private void ShowOnMap(CamClip clip)
 
     private static bool CanShowOnMap(CamClip clip) => clip?.Event is not null && ClipDisplay.HasLocation(clip.Event);
 
-    private void RunOnUiThread(Action action) => _uiInvoker(action);
-
     private void InvokeOnDispatcher(Action action)
     {
         if (_dispatcher.CheckAccess())
@@ -1590,51 +1102,6 @@ partial void OnSelectedClipChanged(CamClip value)
         // In/out marks are fractions of the previous clip's timeline; they mean nothing on the new one, and a trim panel guiding a cut of the old clip would now be lying.
         CancelTrim();
 
-        RecomputeSelectedClipTimeline();
-        OnPropertyChanged(nameof(EventMarkerPosition));
-        OnPropertyChanged(nameof(HasEventMarker));
-        OnPropertyChanged(nameof(EventMarkerTooltip));
-        OnPropertyChanged(nameof(ChunkBoundaries));
-        OnPropertyChanged(nameof(GapPositions));
-        JumpToEventCommand.NotifyCanExecuteChanged();
-
-        // Cancel any in-flight selection load so quickly arrowing through the list doesn't open every clip in turn (which would also drag the selection backwards until the queue drained).
-        _selectionCts?.Cancel();
-        _selectionCts?.Dispose();
-        _selectionCts = null;
-
-        if (value is not null)
-        {
-            _selectionCts = new CancellationTokenSource();
-
-            // Show the now-playing badge on the newly clicked clip right away, instead of only once its media finishes opening.
-            NowPlayingClip = value;
-
-            Log.Debug(
-                "Selected clip changed. ClipName={ClipName}; ClipPath={ClipPath}",
-                value.Name,
-                value.FullPath);
-            _ = PlaySelectedClipAsync(value, _selectionCts.Token);
-        }
+        Playback.Select(value);
     }
-
-    partial void OnPlaybackSpeedChanged(double value)
-    {
-        if (_playerController is not null)
-        {
-            Log.Information("Playback speed changed. Speed={PlaybackSpeed}", value);
-            _playerController.PlaybackSpeed = value;
-        }
-    }
-
-    [RelayCommand(CanExecute = nameof(CanIncreaseSpeed))]
-    private void IncreaseSpeed() =>
-        PlaybackSpeed = PlaybackSpeedSteps.FirstOrDefault(step => step > PlaybackSpeed, PlaybackSpeedSteps[^1]);
-
-    [RelayCommand(CanExecute = nameof(CanDecreaseSpeed))]
-    private void DecreaseSpeed() =>
-        PlaybackSpeed = PlaybackSpeedSteps.LastOrDefault(step => step < PlaybackSpeed, PlaybackSpeedSteps[0]);
-
-    [RelayCommand]
-    private void ResetSpeed() => PlaybackSpeed = 1.0;
 }
diff --git a/SentryDeck/ViewModels/PlaybackViewModel.cs b/SentryDeck/ViewModels/PlaybackViewModel.cs
new file mode 100644
index 0000000..115dc24
--- /dev/null
+++ b/SentryDeck/ViewModels/PlaybackViewModel.cs
@@ -0,0 +1,644 @@
+using System.ComponentModel;
+using CommunityToolkit.Mvvm.ComponentModel;
+using CommunityToolkit.Mvvm.Input;
+using Serilog;
+
+namespace SentryDeck;
+
+/// <summary>
+/// Everything about the clip in the player: loading it when it is selected, the transport controls, the seek bar and its markers, and playback speed.
+/// Wraps the <see cref="VideoPlayerController"/> the view supplies; sibling view-models reach the player only through the members here.
+/// </summary>
+public sealed partial class PlaybackViewModel : ObservableObject
+{
+    private readonly Func<VideoPlayerController> _playerControllerFactory;
+    private readonly Func<Task> _backgroundYield;
+    private readonly Action<Action> _uiInvoker;
+    private readonly ErrorOverlayViewModel _error;
+    private readonly CameraViewsViewModel _cameras;
+    private readonly SeekScrubCoalescer _scrubCoalescer;
+    private VideoPlayerController _playerController;
+    private CancellationTokenSource _selectionCts;
+    private bool _isSeeking;
+
+    // Identifies the current seek gesture.
+    // EndSeekAsync's slow tail (the accurate seek can queue behind in-flight scrubs) may complete after the user has already started a NEW drag; only the completion belonging to the latest gesture may clear _isSeeking, or the position sync would yank the thumb out from under the active drag.
+    private int _seekGeneration;
+
+    // --- Seek-bar overlays for the selected clip (event moment + chunk seams + gaps) ---
+    // Recomputed whenever the selection changes or the controller opens/replaces its media source; plain fields (not ObservableProperty) because they're derived, not independently settable.
+    private double? _eventPosition;
+    private IReadOnlyList<double> _chunkBoundaries = [];
+    private IReadOnlyList<double> _gapPositions = [];
+
+    /// <param name="playerControllerFactory">Creates the playback controller (the view supplies one bound to its Flyleaf hosts).</param>
+    /// <param name="backgroundYield">Yields to the UI before a clip loads so the window stays responsive.</param>
+    /// <param name="uiInvoker">Runs an action on the UI thread.</param>
+    /// <param name="error">Where playback failures are reported.</param>
+    /// <param name="cameras">Refocused on the camera that triggered an event clip once it opens.</param>
+    public PlaybackViewModel(
+        Func<VideoPlayerController> playerControllerFactory,
+        Func<Task> backgroundYield,
+        Action<Action> uiInvoker,
+        ErrorOverlayViewModel error,
+        CameraViewsViewModel cameras)
+    {
+        _playerControllerFactory = playerControllerFactory;
+        _backgroundYield = backgroundYield;
+        _uiInvoker = uiInvoker;
+        _error = error;
+        _cameras = cameras;
+        _scrubCoalescer = new SeekScrubCoalescer(ScrubToAsync);
+    }
+
+    /// <summary>
+    /// Raised when the player moves to another clip on its own or through Next/Previous, so the clip list can follow.
+    /// </summary>
+    public event EventHandler<CamClip> CurrentClipChanged;
+
+    /// <summary>
+    /// Ladder the speed stepper walks: fine increments around 1x, doubling above.
+    /// Flyleaf clamps Player.Speed to [0.125, 16], so 16x is the hard ceiling.
+    /// </summary>
+    public static IReadOnlyList<double> PlaybackSpeedSteps { get; } =
+    [
+        0.25,
+        0.5,
+        0.75,
+        1.0,
+        1.25,
+        1.5,
+        2.0,
+        4.0,
+        8.0,
+        16.0,
+    ];
+
+    /// <summary>The clip the user selected, which this view-model loads into the player.</summary>
+    public CamClip SelectedClip { get; private set; }
+
+    /// <summary>The clip the player has open, or null when nothing is open.</summary>
+    public CamClip CurrentClip => _playerController?.CurrentClip;
+
+    /// <summary>The media source backing the open clip, or null when nothing is open.</summary>
+    public ClipMediaSource OpenedMediaSource => _playerController?.OpenedMediaSource;
+
+    public TimeSpan Duration => _playerController?.Duration ?? TimeSpan.Zero;
+
+    /// <summary>False until the view's Flyleaf-backed controller has been created (FFmpeg missing, or not initialized yet).</summary>
+    public bool HasPlayer => _playerController is not null;
+
+    /// <summary>Speed readout shown on the stepper, e.g. "1x" or "0.25x".</summary>
+    public string PlaybackSpeedText => $"{PlaybackSpeed:0.##}x";
+
+    public bool CanIncreaseSpeed => PlaybackSpeed < PlaybackSpeedSteps[^1];
+
+    public bool CanDecreaseSpeed => PlaybackSpeed > PlaybackSpeedSteps[0];
+
+    public string PositionText => FormatTimeSpan(SeekTargetPosition());
+
+    public string DurationText => FormatTimeSpan(Duration);
+
+    public bool CanSeek => _playerController?.IsMediaOpen == true && !IsLoading && _playerController.Duration > TimeSpan.Zero;
+
+    public bool CanPlayPause => (SelectedClip is not null || IsPlaying) && !IsLoading;
+
+    public bool CanStop => IsPlaying || IsLoading;
+
+    public bool CanGoNext => _playerController?.CanGoNext == true;
+
+    public bool CanGoPrevious => _playerController?.CanGoPrevious == true;
+
+    // Segoe Fluent Icons: Pause (E769) / PlaySolid (F5B0).
+    // Rendered with SymbolThemeFontFamily.
+    public string PlayPauseIcon => IsPlaying ? "" : "";
+
+    /// <summary>The event moment as a 0..1 fraction of the clip timeline (0 when none; pair with <see cref="HasEventMarker"/>).</summary>
+    public double EventMarkerPosition => _eventPosition ?? 0d;
+
+    /// <summary>True when the selected clip has a locatable event moment to mark on the seek bar and jump to.</summary>
+    public bool HasEventMarker => _eventPosition.HasValue;
+
+    /// <summary>Friendly reason + time for the event marker tooltip, e.g. "Honk · 3:53 PM".</summary>
+    public string EventMarkerTooltip => SelectedClip?.Event is { } camEvent && HasEventMarker
+        ? $"{ClipDisplay.ReasonLabel(camEvent)} · {camEvent.Timestamp:t}"
+        : string.Empty;
+
+    /// <summary>Interior chunk-boundary fractions (i/Count for i in 1..Count-1); empty for fewer than two chunks.</summary>
+    public IReadOnlyList<double> ChunkBoundaries => _chunkBoundaries;
+
+    /// <summary>
+    /// Fractional seek-bar positions where the opened clip's media time skips over a wall-clock gap (deleted/corrupt/excluded chunks, or a Sentry idle period).
+    /// Empty until the selected clip's media source has actually been built and opened by the controller.
+    /// </summary>
+    public IReadOnlyList<double> GapPositions => _gapPositions;
+
+    /// <summary>True while the selected clip is loading into the player.</summary>
+    [ObservableProperty]
+    [NotifyPropertyChangedFor(nameof(CanPlayPause))]
+    [NotifyPropertyChangedFor(nameof(CanStop))]
+    [NotifyPropertyChangedFor(nameof(CanSeek))]
+    [NotifyCanExecuteChangedFor(nameof(StepFrameBackwardCommand))]
+    [NotifyCanExecuteChangedFor(nameof(StepFrameForwardCommand))]
+    private bool _isLoading;
+
+    [ObservableProperty]
+    [NotifyPropertyChangedFor(nameof(PositionText))]
+    private double _seekPosition;
+
+    [ObservableProperty]
+    [NotifyPropertyChangedFor(nameof(PlayPauseIcon))]
+    [NotifyPropertyChangedFor(nameof(CanPlayPause))]
+    [NotifyPropertyChangedFor(nameof(CanStop))]
+    private bool _isPlaying;
+
+    // The clip actually loaded in the player (drives the now-playing marker in the list).
+    // Distinct from the selection so a marker can persist even when selection is elsewhere.
+    [ObservableProperty]
+    private CamClip _nowPlayingClip;
+
+    [ObservableProperty]
+    [NotifyPropertyChangedFor(nameof(PlaybackSpeedText))]
+    [NotifyPropertyChangedFor(nameof(CanIncreaseSpeed))]
+    [NotifyPropertyChangedFor(nameof(CanDecreaseSpeed))]
+    [NotifyCanExecuteChangedFor(nameof(IncreaseSpeedCommand))]
+    [NotifyCanExecuteChangedFor(nameof(DecreaseSpeedCommand))]
+    private double _playbackSpeed = 1.0;
+
+    public void InitializePlayer()
+    {
+        if (_playerController is not null)
+            return;
+
+        _playerController = _playerControllerFactory();
+        _playerController.PropertyChanged += PlayerControllerOnPropertyChanged;
+        _playerController.PlaybackSpeed = PlaybackSpeed;
+    }
+
+    public void Shutdown()
+    {
+        _selectionCts?.Cancel();
+        _selectionCts?.Dispose();
+        _selectionCts = null;
+
+        var controller = _playerController;
+        _playerController = null;
+
+        if (controller is null)
+            return;
+
+        controller.PropertyChanged -= PlayerControllerOnPropertyChanged;
+        controller.Dispose();
+    }
+
+    /// <summary>
+    /// Loads <paramref name="clip"/> into the player, or clears the player's selection when it is null.
+    /// A newer selection cancels an older one that is still waiting to load, so quickly arrowing through the list doesn't open every clip in turn.
+    /// </summary>
+    public void Select(CamClip clip)
+    {
+        SelectedClip = clip;
+        OnPropertyChanged(nameof(SelectedClip));
+        OnPropertyChanged(nameof(CanPlayPause));
+
+        RecomputeSelectedClipTimeline();
+        NotifyMarkersChanged();
+
+        _selectionCts?.Cancel();
+        _selectionCts?.Dispose();
+        _selectionCts = null;
+
+        if (clip is not null)
+        {
+            _selectionCts = new CancellationTokenSource();
+
+            // Show the now-playing badge on the newly clicked clip right away, instead of only once its media finishes opening.
+            NowPlayingClip = clip;
+
+            Log.Debug(
+                "Selected clip changed. ClipName={ClipName}; ClipPath={ClipPath}",
+                clip.Name,
+                clip.FullPath);
+            _ = PlaySelectedClipAsync(clip, _selectionCts.Token);
+        }
+    }
+
+    /// <summary>Replaces the player's playlist, which Next and Previous walk.</summary>
+    public void SetPlaylist(IEnumerable<CamClip> clips)
+    {
+        _playerController?.LoadClips(clips);
+        NotifyNavigationChanged();
+    }
+
+    /// <summary>Drops a deleted clip from the player's playlist so Next and Previous skip it.</summary>
+    public void RemoveFromPlaylist(CamClip clip)
+    {
+        _playerController?.RemoveClip(clip);
+        NotifyNavigationChanged();
+    }
+
+    /// <summary>Closes whatever the player has open, releasing its file handles.</summary>
+    public Task StopPlayerAsync() => _playerController?.StopAsync() ?? Task.CompletedTask;
+
+    public Task TogglePlayPauseAsync() => _playerController?.TogglePlayPauseAsync() ?? Task.CompletedTask;
+
+    public Task StepFrameAsync(bool forward) => _playerController?.StepFrameAsync(forward) ?? Task.CompletedTask;
+
+    public Task SeekRelativeAsync(TimeSpan offset)
+    {
+        if (_playerController is not { } controller || !CanSeek)
+        {
+            return Task.CompletedTask;
+        }
+
+        return controller.SeekByAsync(offset);
+    }
+
+    public void BeginSeek()
+    {
+        if (CanSeek)
+        {
+            _seekGeneration++;
+            _isSeeking = true;
+            _scrubCoalescer.Reset();
+
+            // Holds playback paused for the gesture, so each scrub is one cheap paused seek and the release resumes every camera together.
+            // The controller serializes this ahead of the first scrub seek, so it needs no await here.
+            _ = _playerController.BeginScrubAsync();
+        }
+    }
+
+    public async Task EndSeekAsync()
+    {
+        var generation = _seekGeneration;
+
+        if (_playerController is null || !CanSeek)
+        {
+            _isSeeking = false;
+            return;
+        }
+
+        // The gesture is over: drop any scrub value still queued in the coalescer.
+        // When the in-flight scrub completes it would otherwise re-issue that value as a keyframe seek AFTER the accurate seek below (both queue on the controller's serialized-operation lock in that order), leaving the playhead on a keyframe instead of the release point.
+        _scrubCoalescer.CancelPending();
+
+        // _isSeeking stays true until the release seek completes, so the position sync can't pull the thumb back while a scrub seek winds down.
+        // The release seek queues behind any in-flight scrub on the controller's serialized-operation lock, so it always lands last.
+        await _playerController.EndScrubAsync(SeekTargetPosition());
+
+        // Only the latest gesture's completion may end the seeking state: if the user has already grabbed the thumb again, this completion is stale and their new drag owns the flag.
+        if (generation == _seekGeneration)
+        {
+            _isSeeking = false;
+        }
+    }
+
+    /// <summary>
+    /// Called on every seek-bar value change.
+    /// While a seek gesture is active (<see cref="_isSeeking"/>, set by <see cref="BeginSeek"/> on mouse-down for clicks and drags alike), each value feeds the scrub coalescer so the video follows the thumb in near-real-time.
+    /// A plain click therefore issues one scrub seek too; the accurate seek from <see cref="EndSeekAsync"/> runs behind the same serialized lock and always lands last.
+    /// Value changes from playback position sync arrive with <see cref="_isSeeking"/> false and are ignored.
+    /// </summary>
+    public void OnSeekSliderValueChanged()
+    {
+        if (!_isSeeking)
+            return;
+
+        OnPropertyChanged(nameof(PositionText));
+
+        if (CanSeek)
+        {
+            _scrubCoalescer.OnDragValueChanged(SeekTargetPosition());
+        }
+    }
+
+    internal static string FormatTimeSpan(TimeSpan ts)
+    {
+        return ts.TotalHours >= 1
+            ? ts.ToString(@"h\:mm\:ss")
+            : ts.ToString(@"m\:ss");
+    }
+
+    [RelayCommand]
+    private Task PlayPauseAsync() => TogglePlayPauseAsync();
+
+    [RelayCommand]
+    private async Task StopAsync()
+    {
+        if (_playerController is null)
+            return;
+
+        // A selection that is still waiting to load would otherwise start playing right after the stop.
+        _selectionCts?.Cancel();
+
+        await _playerController.StopAsync();
+        IsLoading = false;
+        SeekPosition = 0;
+        NowPlayingClip = null;
+    }
+
+    [RelayCommand(CanExecute = nameof(CanSeek))]
+    private Task StepFrameBackwardAsync() => StepFrameAsync(forward: false);
+
+    [RelayCommand(CanExecute = nameof(CanSeek))]
+    private Task StepFrameForwardAsync() => StepFrameAsync(forward: true);
+
+    [RelayCommand(CanExecute = nameof(HasEventMarker))]
+    private async Task JumpToEventAsync()
+    {
+        if (!HasEventMarker)
+            return;
+
+        Log.Debug("Jumping to event moment. Position={EventMarkerPosition}", EventMarkerPosition);
+        SeekPosition = EventMarkerPosition;
+        await SeekToCurrentPositionAsync();
+    }
+
+    [RelayCommand]
+    private async Task PreviousAsync()
+    {
+        if (_playerController is null)
+            return;
+
+        await _playerController.PreviousAsync();
+        CurrentClipChanged?.Invoke(this, _playerController.CurrentClip);
+    }
+
+    [RelayCommand]
+    private async Task NextAsync()
+    {
+        if (_playerController is null)
+            return;
+
+        await _playerController.NextAsync();
+        CurrentClipChanged?.Invoke(this, _playerController.CurrentClip);
+    }
+
+    [RelayCommand(CanExecute = nameof(CanIncreaseSpeed))]
+    private void IncreaseSpeed() =>
+        PlaybackSpeed = PlaybackSpeedSteps.FirstOrDefault(step => step > PlaybackSpeed, PlaybackSpeedSteps[^1]);
+
+    [RelayCommand(CanExecute = nameof(CanDecreaseSpeed))]
+    private void DecreaseSpeed() =>
+        PlaybackSpeed = PlaybackSpeedSteps.LastOrDefault(step => step < PlaybackSpeed, PlaybackSpeedSteps[0]);
+
+    [RelayCommand]
+    private void ResetSpeed() => PlaybackSpeed = 1.0;
+
+    partial void OnPlaybackSpeedChanged(double value)
+    {
+        if (_playerController is not null)
+        {
+            Log.Information("Playback speed changed. Speed={PlaybackSpeed}", value);
+            _playerController.PlaybackSpeed = value;
+        }
+    }
+
+    private async Task PlaySelectedClipAsync(CamClip clip, CancellationToken cancellationToken)
+    {
+        if (clip is null || _playerController is null)
+            return;
+
+        _error.Clear();
+        IsLoading = true;
+        await _backgroundYield();
+
+        // A newer selection superseded this one while we yielded, so drop it and let the latest win and the selection doesn't rubber-band backwards as earlier, slower loads complete.
+        if (cancellationToken.IsCancellationRequested || !ReferenceEquals(clip, SelectedClip))
+        {
+            // A newer selection's own load owns IsLoading now, but if the selection was cleared outright (deselect, or a filter dropping the clip), no load is in flight and nothing else ever resets the flag, leaving a permanent "Loading…" overlay over the video pane.
+            if (SelectedClip is null)
+            {
+                IsLoading = false;
+            }
+
+            return;
+        }
+
+        try
+        {
+            await _playerController.GoToClipAsync(clip);
+
+            if (cancellationToken.IsCancellationRequested)
+                return;
+
+            // Auto-focus the camera that triggered the event (Full metadata mode).
+            if (clip.Event is not null)
+            {
+                _cameras.SelectedCameraView = _cameras.CameraIdToView(clip.Event.Camera);
+            }
+        }
+        catch (Exception ex)
+        {
+            if (cancellationToken.IsCancellationRequested)
+            {
+                // Same stuck-overlay guard as the pre-load early-return above.
+                if (SelectedClip is null)
+                {
+                    IsLoading = false;
+                }
+
+                return;
+            }
+
+            IsLoading = false;
+            Log.Error(
+                ex,
+                "Failed to play selected clip. ClipName={ClipName}; ClipPath={ClipPath}",
+                clip.Name,
+                clip.FullPath);
+            _error.Show("Playback Failed", $"Could not play clip: {clip.Name}\n\nError: {ex.Message}");
+        }
+    }
+
+    private async Task SeekToCurrentPositionAsync()
+    {
+        if (_playerController is null)
+            return;
+
+        var duration = _playerController.Duration;
+        if (duration.TotalSeconds > 0)
+        {
+            await _playerController.SeekAsync(SeekTargetPosition());
+        }
+    }
+
+    private Task ScrubToAsync(TimeSpan position) =>
+        _playerController?.ScrubSeekAsync(position) ?? Task.CompletedTask;
+
+    private TimeSpan SeekTargetPosition() => TimeSpan.FromSeconds(SeekPosition * Duration.TotalSeconds);
+
+    // Derives the seek-bar overlays for the selected clip: the event moment, the interior chunk-boundary ticks, and gap ticks (mapped onto the 0..1 seek axis).
+    // Nulls out cleanly when the selection is cleared or the clip has no usable event metadata.
+    //
+    // Prefers the controller's actually-opened ClipMediaSource when it belongs to this clip: that source has real probed durations and gap-aware wall-clock mapping (see ClipMediaSource.ToMediaTime), so its positions match what's actually playing.
+    // Selecting a clip is synchronous but opening its media is not, so immediately after selection (or for a clip that never opens, e.g. in tests with no controller) there is no opened source yet; a ClipTimeline estimate (uniform assumed chunk length) is used as a same-frame placeholder so the markers don't flash empty, and is superseded once OpenedMediaSource changes.
+    private void RecomputeSelectedClipTimeline()
+    {
+        var clip = SelectedClip;
+        if (clip is null)
+        {
+            _eventPosition = null;
+            _chunkBoundaries = [];
+            _gapPositions = [];
+            return;
+        }
+
+        var mediaSource = _playerController?.CurrentClip == clip ? _playerController?.OpenedMediaSource : null;
+
+        if (mediaSource is not null && mediaSource.Duration > TimeSpan.Zero)
+        {
+            RecomputeFromMediaSource(clip, mediaSource);
+        }
+        else
+        {
+            RecomputeFromEstimatedTimeline(clip);
+        }
+    }
+
+    private void RecomputeFromMediaSource(CamClip clip, ClipMediaSource mediaSource)
+    {
+        var durationSeconds = mediaSource.Duration.TotalSeconds;
+
+        _chunkBoundaries = mediaSource.ChunkStarts.Count < 2
+            ? []
+            : mediaSource.ChunkStarts.Skip(1).Select(start => start.TotalSeconds / durationSeconds).ToList();
+
+        _gapPositions = mediaSource.GapPositions
+            .Select(position => position.TotalSeconds / durationSeconds)
+            .ToList();
+
+        var camEvent = clip.Event;
+        if (camEvent is null || camEvent.Timestamp == default)
+        {
+            _eventPosition = null;
+            return;
+        }
+
+        // Fraction 0 is a real position: an event that fired on the first recorded frame (or one snapped forward to the start of the footage) still deserves its marker.
+        var mediaTime = mediaSource.ToMediaTime(camEvent.Timestamp);
+        var fraction = mediaTime?.TotalSeconds / durationSeconds;
+        _eventPosition = fraction is >= 0 and <= 1 ? fraction : null;
+    }
+
+    // Fallback used before the selected clip's media has actually been opened (or when it never will be, e.g. no controller in tests): the legacy uniform-chunk-length estimate.
+    // Carries no gap information, since gaps can only be known once the builder has probed real durations.
+    private void RecomputeFromEstimatedTimeline(CamClip clip)
+    {
+        var timeline = new ClipTimeline(clip.Chunks);
+        _chunkBoundaries = timeline.Count < 2
+            ? []
+            : Enumerable.Range(1, timeline.Count - 1).Select(i => (double)i / timeline.Count).ToList();
+        _gapPositions = [];
+
+        var camEvent = clip.Event;
+        if (camEvent is null || camEvent.Timestamp == default || clip.Chunks.Count == 0 || timeline.Duration <= TimeSpan.Zero)
+        {
+            _eventPosition = null;
+            return;
+        }
+
+        // The event landing at or after the start and no later than the modeled end is markable (exactly 0 = the event fired on the first recorded frame); clock skew (fraction < 0) or an event past the estimate (> 1) yields no marker.
+        var fraction = (camEvent.Timestamp - clip.Chunks[0].Timestamp).TotalSeconds / timeline.Duration.TotalSeconds;
+        _eventPosition = fraction is >= 0 and <= 1 ? fraction : null;
+    }
+
+    private void NotifyMarkersChanged()
+    {
+        OnPropertyChanged(nameof(EventMarkerPosition));
+        OnPropertyChanged(nameof(HasEventMarker));
+        OnPropertyChanged(nameof(EventMarkerTooltip));
+        OnPropertyChanged(nameof(ChunkBoundaries));
+        OnPropertyChanged(nameof(GapPositions));
+        JumpToEventCommand.NotifyCanExecuteChanged();
+    }
+
+    // Sibling view-models gate on CanSeek (the trim marks and export), so it is re-announced whenever anything it reads changes, even if its value didn't.
+    private void NotifyCanSeekChanged()
+    {
+        OnPropertyChanged(nameof(CanSeek));
+        StepFrameBackwardCommand.NotifyCanExecuteChanged();
+        StepFrameForwardCommand.NotifyCanExecuteChanged();
+    }
+
+    private void NotifyNavigationChanged()
+    {
+        OnPropertyChanged(nameof(CanPlayPause));
+        OnPropertyChanged(nameof(CanGoNext));
+        OnPropertyChanged(nameof(CanGoPrevious));
+    }
+
+    private void UpdateSeekPositionFromController()
+    {
+        if (_playerController is null || _isSeeking)
+            return;
+
+        var duration = _playerController.Duration;
+        SeekPosition = duration.TotalSeconds > 0
+            ? Math.Clamp(_playerController.Position.TotalSeconds / duration.TotalSeconds, 0, 1)
+            : 0;
+    }
+
+    private void PlayerControllerOnPropertyChanged(object sender, PropertyChangedEventArgs e)
+    {
+        if (string.IsNullOrWhiteSpace(e.PropertyName))
+            return;
+
+        _uiInvoker(() => HandlePlayerControllerPropertyChanged(e.PropertyName));
+    }
+
+    private void HandlePlayerControllerPropertyChanged(string propertyName)
+    {
+        if (_playerController is null)
+            return;
+
+        switch (propertyName)
+        {
+            case nameof(VideoPlayerController.IsLoading):
+                IsLoading = _playerController.IsLoading;
+                break;
+
+            case nameof(VideoPlayerController.IsPlaying):
+                IsPlaying = _playerController.IsPlaying;
+                break;
+
+            case nameof(VideoPlayerController.Duration):
+                UpdateSeekPositionFromController();
+                OnPropertyChanged(nameof(Duration));
+                OnPropertyChanged(nameof(DurationText));
+                OnPropertyChanged(nameof(PositionText));
+                NotifyCanSeekChanged();
+                break;
+
+            case nameof(VideoPlayerController.Position):
+                UpdateSeekPositionFromController();
+                break;
+
+            case nameof(VideoPlayerController.OpenedMediaSource):
+                // The controller finished (re)building the media source for the selected clip (or one under recovery from a corrupt chunk).
+                // Siblings that hold positions against the old timeline hear about it first; then the gap-aware overlays are refreshed now that real probed durations/timestamps are available.
+                OnPropertyChanged(nameof(OpenedMediaSource));
+                RecomputeSelectedClipTimeline();
+                NotifyMarkersChanged();
+                break;
+
+            case nameof(VideoPlayerController.ErrorMessage):
+                if (_playerController.ErrorMessage is not null)
+                {
+                    _error.Show("Playback Error", _playerController.ErrorMessage);
+                }
+
+                break;
+
+            case nameof(VideoPlayerController.CurrentClip):
+                CurrentClipChanged?.Invoke(this, _playerController.CurrentClip);
+                NowPlayingClip = _playerController.CurrentClip;
+                NotifyNavigationChanged();
+                break;
+
+            case nameof(VideoPlayerController.IsMediaOpen):
+                NotifyCanSeekChanged();
+                break;
+        }
+    }
+}

From 79fc7744325bea7a1a4bb3878825f95d223adb3e Mon Sep 17 00:00:00 2001
From: Daniel Chalmers <daniel.chalmers@outlook.com>
Date: Thu, 24 Sep 2026 07:45:24 -0500
Subject: [PATCH 6/8] Move the clip library into its own view-model

ClipLibraryViewModel owns the clip list: scanning dashcam folders, search with its debounce, the selected clip, and the per-clip context menu actions (open folder, copy, delete, show on map). The main view-model reacts to the selection (camera tiles, trim, loading the clip) and feeds clip changes from the player back into it.
---
 .../MainWindowViewModelTests.Clips.cs         | 174 +++----
 .../MainWindowViewModelTests.Keyboard.cs      |  22 +-
 .../MainWindowViewModelTests.Markers.cs       |  36 +-
 .../MainWindowViewModelTests.Playback.cs      |   6 +-
 .../MainWindowViewModelTests.Trimming.cs      |   4 +-
 SentryDeck.Tests/MainWindowViewModelTests.cs  |  24 +-
 SentryDeck/MainWindow.xaml                    |  42 +-
 SentryDeck/MainWindowViewModel.cs             | 429 ++----------------
 SentryDeck/ViewModels/ClipLibraryViewModel.cs | 403 ++++++++++++++++
 9 files changed, 596 insertions(+), 544 deletions(-)
 create mode 100644 SentryDeck/ViewModels/ClipLibraryViewModel.cs

diff --git a/SentryDeck.Tests/MainWindowViewModelTests.Clips.cs b/SentryDeck.Tests/MainWindowViewModelTests.Clips.cs
index 9c8e560..c853c75 100644
--- a/SentryDeck.Tests/MainWindowViewModelTests.Clips.cs
+++ b/SentryDeck.Tests/MainWindowViewModelTests.Clips.cs
@@ -14,9 +14,9 @@ public async Task FilteredClips_OrderNewestFirst()
         var clips = TestClips.Create(3); // timestamps increase with index
         var vm = new MainWindowViewModel(() => null!, clipLoader: _ => clips);
 
-        await vm.LoadClipsAsync(new[] { "root" });
+        await vm.Library.LoadClipsAsync(new[] { "root" });
 
-        vm.FilteredClips.Select(c => c.Name).ShouldBe(new[] { "Clip 2", "Clip 1", "Clip 0" });
+        vm.Library.FilteredClips.Select(c => c.Name).ShouldBe(new[] { "Clip 2", "Clip 1", "Clip 0" });
     }
 
     [Fact]
@@ -24,11 +24,11 @@ public async Task FilteredClips_FiltersByNameCaseInsensitively()
     {
         var clips = TestClips.Create(3);
         var vm = new MainWindowViewModel(() => null!, clipLoader: _ => clips);
-        await vm.LoadClipsAsync(new[] { "root" });
+        await vm.Library.LoadClipsAsync(new[] { "root" });
 
-        vm.FilterText = "clip 1";
+        vm.Library.FilterText = "clip 1";
 
-        vm.FilteredClips.Single().Name.ShouldBe("Clip 1");
+        vm.Library.FilteredClips.Single().Name.ShouldBe("Clip 1");
     }
 
     [Fact]
@@ -37,11 +37,11 @@ public async Task FilteredClips_FiltersByPath()
         // TestClips share a folder path but have distinct names, so a path-only match keeps them all.
         var clips = TestClips.Create(2);
         var vm = new MainWindowViewModel(() => null!, clipLoader: _ => clips);
-        await vm.LoadClipsAsync(new[] { "root" });
+        await vm.Library.LoadClipsAsync(new[] { "root" });
 
-        vm.FilterText = clips[0].FullPath;
+        vm.Library.FilterText = clips[0].FullPath;
 
-        vm.FilteredClips.Count.ShouldBe(2);
+        vm.Library.FilteredClips.Count.ShouldBe(2);
     }
 
     [Fact]
@@ -53,11 +53,11 @@ public async Task FilteredClips_FiltersByCity()
             ClipWithEvent("B", "user_interaction_honk", "San Antonio"),
         };
         var vm = new MainWindowViewModel(() => null!, clipLoader: _ => clips);
-        await vm.LoadClipsAsync(new[] { "root" });
+        await vm.Library.LoadClipsAsync(new[] { "root" });
 
-        vm.FilterText = "hutto";
+        vm.Library.FilterText = "hutto";
 
-        vm.FilteredClips.Single().Name.ShouldBe("A");
+        vm.Library.FilteredClips.Single().Name.ShouldBe("A");
     }
 
     [Fact]
@@ -69,11 +69,11 @@ public async Task FilteredClips_FiltersByFriendlyReason()
             ClipWithEvent("Saver", "user_interaction_dashcam_launcher_action_tapped", "X"),
         };
         var vm = new MainWindowViewModel(() => null!, clipLoader: _ => clips);
-        await vm.LoadClipsAsync(new[] { "root" });
+        await vm.Library.LoadClipsAsync(new[] { "root" });
 
-        vm.FilterText = "saved";
+        vm.Library.FilterText = "saved";
 
-        vm.FilteredClips.Single().Name.ShouldBe("Saver");
+        vm.Library.FilteredClips.Single().Name.ShouldBe("Saver");
     }
 
     [Fact]
@@ -81,26 +81,26 @@ public async Task ClipCount_ReflectsFilteredCount()
     {
         var clips = TestClips.Create(3);
         var vm = new MainWindowViewModel(() => null!, clipLoader: _ => clips);
-        await vm.LoadClipsAsync(new[] { "root" });
+        await vm.Library.LoadClipsAsync(new[] { "root" });
 
-        vm.ClipCount.ShouldBe(3);
+        vm.Library.ClipCount.ShouldBe(3);
 
-        vm.FilterText = "Clip 1";
+        vm.Library.FilterText = "Clip 1";
 
-        vm.ClipCount.ShouldBe(1);
+        vm.Library.ClipCount.ShouldBe(1);
     }
 
     [Fact]
     public void ClearFilter_ResetsFilterTextAndFlag()
     {
         var vm = CreateViewModel();
-        vm.FilterText = "abc";
-        vm.HasFilterText.ShouldBeTrue();
+        vm.Library.FilterText = "abc";
+        vm.Library.HasFilterText.ShouldBeTrue();
 
-        vm.ClearFilterCommand.Execute(null);
+        vm.Library.ClearFilterCommand.Execute(null);
 
-        vm.FilterText.ShouldBe(string.Empty);
-        vm.HasFilterText.ShouldBeFalse();
+        vm.Library.FilterText.ShouldBe(string.Empty);
+        vm.Library.HasFilterText.ShouldBeFalse();
     }
 
     [Fact]
@@ -108,22 +108,22 @@ public async Task TypingInSearch_DoesNotRebindTheListPerKeystroke()
     {
         var clips = TestClips.Create(3);
         var vm = new MainWindowViewModel(() => null!, clipLoader: _ => clips);
-        await vm.LoadClipsAsync(["root"]);
+        await vm.Library.LoadClipsAsync(["root"]);
 
         var changed = new List<string>();
-        vm.PropertyChanged += (_, e) => changed.Add(e.PropertyName);
+        vm.Library.PropertyChanged += (_, e) => changed.Add(e.PropertyName);
 
-        vm.FilterText = "C";
-        vm.FilterText = "Cl";
-        vm.FilterText = "Cli";
+        vm.Library.FilterText = "C";
+        vm.Library.FilterText = "Cl";
+        vm.Library.FilterText = "Cli";
 
         // The list rebind is deferred to a debounce timer (which never ticks in tests) so the ListBox doesn't rebuild and replay its fade on every keystroke.
         // Wiring FilteredClips/ClipCount straight onto FilterText would look harmless and quietly undo that.
-        changed.ShouldNotContain(nameof(MainWindowViewModel.FilteredClips));
-        changed.ShouldNotContain(nameof(MainWindowViewModel.ClipCount));
+        changed.ShouldNotContain(nameof(ClipLibraryViewModel.FilteredClips));
+        changed.ShouldNotContain(nameof(ClipLibraryViewModel.ClipCount));
 
         // The clear affordance is the one part that stays immediate.
-        changed.ShouldContain(nameof(MainWindowViewModel.HasFilterText));
+        changed.ShouldContain(nameof(ClipLibraryViewModel.HasFilterText));
     }
 
     [Fact]
@@ -133,8 +133,8 @@ public void ShowOnMap_DisabledWithoutCoordinates()
         var noLocation = ClipWithEvent("A", "user_interaction_honk", "Hutto");
         var withLocation = ClipWithEvent("B", "user_interaction_honk", "Hutto", 30.5m, -97.5m);
 
-        vm.ShowOnMapCommand.CanExecute(noLocation).ShouldBeFalse();
-        vm.ShowOnMapCommand.CanExecute(withLocation).ShouldBeTrue();
+        vm.Library.ShowOnMapCommand.CanExecute(noLocation).ShouldBeFalse();
+        vm.Library.ShowOnMapCommand.CanExecute(withLocation).ShouldBeTrue();
     }
 
     // --- Scanning: what the sidebar and the overlay show when there is nothing to scan, or a root can't be read.
@@ -145,7 +145,7 @@ public async Task LoadClips_WithNoRoots_ShowsDismissibleEmptyState()
     {
         var vm = CreateViewModel();
 
-        await vm.LoadClipsAsync([]);
+        await vm.Library.LoadClipsAsync([]);
 
         // First run with no USB drive attached: a friendly prompt the user can dismiss to reach the rest of the app, not a scary error they're stuck behind.
         vm.Error.Title.ShouldBe("No dashcam footage yet");
@@ -153,7 +153,7 @@ public async Task LoadClips_WithNoRoots_ShowsDismissibleEmptyState()
         vm.Error.CanDismiss.ShouldBeTrue();
         vm.Error.IsVisible.ShouldBeTrue();
         vm.ShowStatusOverlay.ShouldBeTrue();
-        vm.ClipCount.ShouldBe(0);
+        vm.Library.ClipCount.ShouldBe(0);
     }
 
     [Fact]
@@ -161,7 +161,7 @@ public async Task LoadClips_AccessDenied_ShowsAccessDeniedError()
     {
         var vm = new MainWindowViewModel(() => null!, clipLoader: _ => throw new UnauthorizedAccessException("denied"));
 
-        await vm.LoadClipsAsync([@"D:\TeslaCam"]);
+        await vm.Library.LoadClipsAsync([@"D:\TeslaCam"]);
 
         // A permissions problem gets its own title and remedy; it isn't the empty state.
         vm.Error.Title.ShouldBe("Access Denied");
@@ -175,7 +175,7 @@ public async Task LoadClips_LoaderThrows_ShowsGenericLoadError()
     {
         var vm = new MainWindowViewModel(() => null!, clipLoader: _ => throw new IOException("the drive was removed"));
 
-        await vm.LoadClipsAsync([@"E:\TeslaCam"]);
+        await vm.Library.LoadClipsAsync([@"E:\TeslaCam"]);
 
         // Both halves matter for a bug report: which folder failed, and what the failure was.
         vm.Error.Title.ShouldBe("Error Loading Clips");
@@ -199,10 +199,10 @@ public async Task LoadClips_OneRootFails_KeepsClipsFromTheHealthyRoot()
                 return clips;
             });
 
-        await vm.LoadClipsAsync(["bad", "good"]);
+        await vm.Library.LoadClipsAsync(["bad", "good"]);
 
         // Scanning is per-root: one unreadable drive reports itself but must not cost the user the library on the drive that is still plugged in.
-        vm.ClipCount.ShouldBe(2);
+        vm.Library.ClipCount.ShouldBe(2);
         vm.Error.IsVisible.ShouldBeTrue();
         vm.Error.Title.ShouldBe("Error Loading Clips");
     }
@@ -222,7 +222,7 @@ private static List<CamClip> ClipsWithDistinctPaths(int count) =>
     private static async Task<MainWindowViewModel> LoadedViewModelAsync(IReadOnlyList<CamClip> clips)
     {
         var vm = new MainWindowViewModel(() => null!, clipLoader: _ => clips);
-        await vm.LoadClipsAsync(new[] { "root" });
+        await vm.Library.LoadClipsAsync(new[] { "root" });
         return vm;
     }
 
@@ -231,8 +231,8 @@ public void DeleteClipCommand_CanExecute_RequiresAClip()
     {
         var vm = CreateViewModel();
 
-        vm.DeleteClipCommand.CanExecute(null).ShouldBeFalse();
-        vm.DeleteClipCommand.CanExecute(TestClips.Create(1)[0]).ShouldBeTrue();
+        vm.Library.DeleteClipCommand.CanExecute(null).ShouldBeFalse();
+        vm.Library.DeleteClipCommand.CanExecute(TestClips.Create(1)[0]).ShouldBeTrue();
     }
 
     [Fact]
@@ -241,15 +241,15 @@ public async Task DeleteClip_Confirmed_RecyclesFolder_AndRemovesFromList()
         var clips = ClipsWithDistinctPaths(3);
         var vm = await LoadedViewModelAsync(clips);
         string recycledPath = null;
-        vm.ConfirmDeleteClip = _ => true;
-        vm.RecycleClipFolder = path => recycledPath = path;
+        vm.Library.ConfirmDeleteClip = _ => true;
+        vm.Library.RecycleClipFolder = path => recycledPath = path;
 
-        var target = vm.FilteredClips.Single(clip => clip.Name == "Clip 1");
-        await vm.DeleteClipCommand.ExecuteAsync(target);
+        var target = vm.Library.FilteredClips.Single(clip => clip.Name == "Clip 1");
+        await vm.Library.DeleteClipCommand.ExecuteAsync(target);
 
         recycledPath.ShouldBe(target.FullPath);
-        vm.FilteredClips.ShouldNotContain(target);
-        vm.ClipCount.ShouldBe(2);
+        vm.Library.FilteredClips.ShouldNotContain(target);
+        vm.Library.ClipCount.ShouldBe(2);
     }
 
     [Fact]
@@ -258,15 +258,15 @@ public async Task DeleteClip_Cancelled_KeepsClip_AndDoesNotRecycle()
         var clips = ClipsWithDistinctPaths(2);
         var vm = await LoadedViewModelAsync(clips);
         var recycleCalls = 0;
-        vm.ConfirmDeleteClip = _ => false;
-        vm.RecycleClipFolder = _ => recycleCalls++;
+        vm.Library.ConfirmDeleteClip = _ => false;
+        vm.Library.RecycleClipFolder = _ => recycleCalls++;
 
-        var target = vm.FilteredClips[0];
-        await vm.DeleteClipCommand.ExecuteAsync(target);
+        var target = vm.Library.FilteredClips[0];
+        await vm.Library.DeleteClipCommand.ExecuteAsync(target);
 
         recycleCalls.ShouldBe(0);
-        vm.ClipCount.ShouldBe(2);
-        vm.FilteredClips.ShouldContain(target);
+        vm.Library.ClipCount.ShouldBe(2);
+        vm.Library.FilteredClips.ShouldContain(target);
     }
 
     [Fact]
@@ -274,18 +274,18 @@ public async Task DeleteClip_TheSelectedClip_ClearsSelectionAndNowPlaying()
     {
         var clips = ClipsWithDistinctPaths(2);
         var vm = await LoadedViewModelAsync(clips);
-        vm.ConfirmDeleteClip = _ => true;
-        vm.RecycleClipFolder = _ => { };
+        vm.Library.ConfirmDeleteClip = _ => true;
+        vm.Library.RecycleClipFolder = _ => { };
 
-        var target = vm.FilteredClips[0];
-        vm.SelectedClip = target; // sets NowPlayingClip too (see OnSelectedClipChanged)
+        var target = vm.Library.FilteredClips[0];
+        vm.Library.SelectedClip = target; // sets NowPlayingClip too (see OnSelectedClipChanged)
         vm.Playback.NowPlayingClip.ShouldBe(target);
 
-        await vm.DeleteClipCommand.ExecuteAsync(target);
+        await vm.Library.DeleteClipCommand.ExecuteAsync(target);
 
-        vm.SelectedClip.ShouldBeNull();
+        vm.Library.SelectedClip.ShouldBeNull();
         vm.Playback.NowPlayingClip.ShouldBeNull();
-        vm.FilteredClips.ShouldNotContain(target);
+        vm.Library.FilteredClips.ShouldNotContain(target);
     }
 
     [Fact]
@@ -293,18 +293,18 @@ public async Task DeleteClip_NotTheSelectedClip_LeavesSelectionIntact()
     {
         var clips = ClipsWithDistinctPaths(3);
         var vm = await LoadedViewModelAsync(clips);
-        vm.ConfirmDeleteClip = _ => true;
-        vm.RecycleClipFolder = _ => { };
+        vm.Library.ConfirmDeleteClip = _ => true;
+        vm.Library.RecycleClipFolder = _ => { };
 
-        var selected = vm.FilteredClips.Single(clip => clip.Name == "Clip 2");
-        var victim = vm.FilteredClips.Single(clip => clip.Name == "Clip 0");
-        vm.SelectedClip = selected;
+        var selected = vm.Library.FilteredClips.Single(clip => clip.Name == "Clip 2");
+        var victim = vm.Library.FilteredClips.Single(clip => clip.Name == "Clip 0");
+        vm.Library.SelectedClip = selected;
 
-        await vm.DeleteClipCommand.ExecuteAsync(victim);
+        await vm.Library.DeleteClipCommand.ExecuteAsync(victim);
 
-        vm.SelectedClip.ShouldBe(selected);
-        vm.FilteredClips.ShouldNotContain(victim);
-        vm.ClipCount.ShouldBe(2);
+        vm.Library.SelectedClip.ShouldBe(selected);
+        vm.Library.FilteredClips.ShouldNotContain(victim);
+        vm.Library.ClipCount.ShouldBe(2);
     }
 
     [Fact]
@@ -312,16 +312,16 @@ public async Task DeleteClip_WhenRecycleFails_ShowsError_AndKeepsClip()
     {
         var clips = ClipsWithDistinctPaths(2);
         var vm = await LoadedViewModelAsync(clips);
-        vm.ConfirmDeleteClip = _ => true;
-        vm.RecycleClipFolder = _ => throw new IOException("The file is in use.");
+        vm.Library.ConfirmDeleteClip = _ => true;
+        vm.Library.RecycleClipFolder = _ => throw new IOException("The file is in use.");
 
-        var target = vm.FilteredClips[0];
-        await vm.DeleteClipCommand.ExecuteAsync(target);
+        var target = vm.Library.FilteredClips[0];
+        await vm.Library.DeleteClipCommand.ExecuteAsync(target);
 
         vm.Error.IsVisible.ShouldBeTrue();
         vm.Error.Title.ShouldBe("Delete Failed");
-        vm.ClipCount.ShouldBe(2);
-        vm.FilteredClips.ShouldContain(target);
+        vm.Library.ClipCount.ShouldBe(2);
+        vm.Library.FilteredClips.ShouldContain(target);
     }
 
     // --- Deleting the clip that is actually open: the point of the feature, and the only path that touches the player.
@@ -334,11 +334,11 @@ public async Task DeleteClip_TheOpenClip_StopsPlaybackBeforeRecycling()
         var (vm, _, front) = CreateViewModelWithOpenedClip(clipFiles.Clip, uiInvoker: action => action());
         var closesBeforeDelete = front.Count("close");
         var closesWhenRecycled = -1;
-        vm.ConfirmDeleteClip = _ => true;
-        vm.RecycleClipFolder = _ => closesWhenRecycled = front.Count("close");
+        vm.Library.ConfirmDeleteClip = _ => true;
+        vm.Library.RecycleClipFolder = _ => closesWhenRecycled = front.Count("close");
         vm.Playback.SeekPosition = 0.5;
 
-        await vm.DeleteClipCommand.ExecuteAsync(clipFiles.Clip);
+        await vm.Library.DeleteClipCommand.ExecuteAsync(clipFiles.Clip);
 
         // Windows can't recycle a folder whose files are still locked, so playback must already be stopped when the shell operation runs -- not merely by the time delete returns.
         closesWhenRecycled.ShouldBeGreaterThan(closesBeforeDelete);
@@ -351,16 +351,16 @@ public async Task DeleteClip_TheOpenClip_RemovesItFromThePlayerPlaylist()
         using var clipFiles = TestClipFiles.Create(chunkCount: 1);
         var clip = clipFiles.Clip;
         var (vm, controller, _) = CreateViewModelWithOpenedClip(clip, uiInvoker: action => action());
-        vm.ConfirmDeleteClip = _ => true;
-        vm.RecycleClipFolder = _ => { };
-        vm.SelectedClip = clip; // sets NowPlayingClip too (see OnSelectedClipChanged)
+        vm.Library.ConfirmDeleteClip = _ => true;
+        vm.Library.RecycleClipFolder = _ => { };
+        vm.Library.SelectedClip = clip; // sets NowPlayingClip too (see OnSelectedClipChanged)
 
-        await vm.DeleteClipCommand.ExecuteAsync(clip);
+        await vm.Library.DeleteClipCommand.ExecuteAsync(clip);
 
         // Next/Previous walk the controller's playlist, so a deleted clip left behind in it would navigate straight back to a folder that no longer exists.
         controller.Playlist.Clips.ShouldNotContain(clip);
         vm.Playback.NowPlayingClip.ShouldBeNull();
-        vm.SelectedClip.ShouldBeNull();
+        vm.Library.SelectedClip.ShouldBeNull();
     }
 
     [Fact]
@@ -368,10 +368,10 @@ public async Task FilteredClips_NoMatch_IsEmpty()
     {
         var clips = TestClips.Create(3);
         var vm = new MainWindowViewModel(() => null!, clipLoader: _ => clips);
-        await vm.LoadClipsAsync(new[] { "root" });
+        await vm.Library.LoadClipsAsync(new[] { "root" });
 
-        vm.FilterText = "no-such-clip";
+        vm.Library.FilterText = "no-such-clip";
 
-        vm.FilteredClips.ShouldBeEmpty();
+        vm.Library.FilteredClips.ShouldBeEmpty();
     }
 }
diff --git a/SentryDeck.Tests/MainWindowViewModelTests.Keyboard.cs b/SentryDeck.Tests/MainWindowViewModelTests.Keyboard.cs
index 1282335..4200209 100644
--- a/SentryDeck.Tests/MainWindowViewModelTests.Keyboard.cs
+++ b/SentryDeck.Tests/MainWindowViewModelTests.Keyboard.cs
@@ -105,7 +105,7 @@ public void StopCommand_ClearsNowPlayingClip()
         using var clipFiles = TestClipFiles.Create(chunkCount: 1);
         var (vm, _, front) = CreateViewModelWithOpenedClip(clipFiles.Clip);
         var closesAfterOpen = front.Count("close");
-        vm.SelectedClip = clipFiles.Clip; // sets NowPlayingClip too (see OnSelectedClipChanged)
+        vm.Library.SelectedClip = clipFiles.Clip; // sets NowPlayingClip too (see OnSelectedClipChanged)
 
         RunPinnedToTestThread(() => vm.Playback.StopCommand.ExecuteAsync(null));
 
@@ -127,12 +127,12 @@ public async Task DeselectingWhileSelectionLoadIsYielding_ClearsTheLoadingOverla
             backgroundYield: () => yieldGate.Task);
         vm.InitializePlayer();
 
-        vm.SelectedClip = ClipWithChunks(1);
+        vm.Library.SelectedClip = ClipWithChunks(1);
         vm.IsLoading.ShouldBeTrue();
 
         // Clear the selection before the yield resumes (Ctrl+click deselect, or a search filter dropping the clip).
         // The superseded load must not leave IsLoading stuck true forever.
-        vm.SelectedClip = null;
+        vm.Library.SelectedClip = null;
         yieldGate.SetResult();
 
         await Wait.UntilAsync(() => !vm.IsLoading);
@@ -153,8 +153,8 @@ public async Task SupersededSelection_DoesNotClearTheNewerLoadsLoadingState()
 
         var superseded = ClipWithCameras(SixCameras);
         var winner = ClipWithCamerasAndEventCamera(eventCamera: 7, SixCameras);
-        vm.SelectedClip = superseded;
-        vm.SelectedClip = winner;
+        vm.Library.SelectedClip = superseded;
+        vm.Library.SelectedClip = winner;
 
         yieldGate.SetResult();
 
@@ -163,7 +163,7 @@ public async Task SupersededSelection_DoesNotClearTheNewerLoadsLoadingState()
         await Wait.UntilAsync(() => vm.Cameras.SelectedCameraView == CameraNames.Back);
         vm.IsLoading.ShouldBeTrue();
         vm.Playback.NowPlayingClip.ShouldBe(winner);
-        vm.SelectedClip.ShouldBe(winner);
+        vm.Library.SelectedClip.ShouldBe(winner);
     }
 
     [Fact]
@@ -172,12 +172,12 @@ public void OpenFolderAndRefresh_AreDisabledWhileClipsAreScanning()
         // Both commands funnel into LoadClipsAsync, which has no re-entrancy protection: a second load started mid-scan would interleave with the first and merge both roots' clips.
         var vm = CreateViewModel();
 
-        vm.OpenFolderCommand.CanExecute(null).ShouldBeTrue();
-        vm.RefreshClipsCommand.CanExecute(null).ShouldBeTrue();
+        vm.Library.OpenFolderCommand.CanExecute(null).ShouldBeTrue();
+        vm.Library.RefreshClipsCommand.CanExecute(null).ShouldBeTrue();
 
-        vm.IsLoadingClips = true;
+        vm.Library.IsLoadingClips = true;
 
-        vm.OpenFolderCommand.CanExecute(null).ShouldBeFalse();
-        vm.RefreshClipsCommand.CanExecute(null).ShouldBeFalse();
+        vm.Library.OpenFolderCommand.CanExecute(null).ShouldBeFalse();
+        vm.Library.RefreshClipsCommand.CanExecute(null).ShouldBeFalse();
     }
 }
diff --git a/SentryDeck.Tests/MainWindowViewModelTests.Markers.cs b/SentryDeck.Tests/MainWindowViewModelTests.Markers.cs
index 61c6230..6e96087 100644
--- a/SentryDeck.Tests/MainWindowViewModelTests.Markers.cs
+++ b/SentryDeck.Tests/MainWindowViewModelTests.Markers.cs
@@ -14,7 +14,7 @@ public void EventMarker_NearClipEnd_MapsToHighFraction()
         var vm = CreateViewModel();
 
         // 10 one-minute chunks (600s modeled); event at 9m30s in -> 0.95.
-        vm.SelectedClip = ClipWithChunksAndEvent(10, TimeSpan.FromSeconds(570));
+        vm.Library.SelectedClip = ClipWithChunksAndEvent(10, TimeSpan.FromSeconds(570));
 
         vm.Playback.HasEventMarker.ShouldBeTrue();
         vm.Playback.EventMarkerPosition.ShouldBe(0.95, 0.0001);
@@ -26,7 +26,7 @@ public void EventMarker_AbsentWithoutEvent()
     {
         var vm = CreateViewModel();
 
-        vm.SelectedClip = ClipWithChunks(3);
+        vm.Library.SelectedClip = ClipWithChunks(3);
 
         vm.Playback.HasEventMarker.ShouldBeFalse();
         vm.Playback.EventMarkerPosition.ShouldBe(0);
@@ -40,7 +40,7 @@ public void EventMarker_AbsentWhenEventTimestampIsDefault()
         var chunks = ClipWithChunks(3).Chunks;
         var camEvent = new CamEvent { Reason = "user_interaction_honk" }; // Timestamp == default
 
-        vm.SelectedClip = new CamClip(System.IO.Path.GetTempPath(), "Default TS", new DateTime(2025, 1, 1, 12, 0, 0), chunks, camEvent);
+        vm.Library.SelectedClip = new CamClip(System.IO.Path.GetTempPath(), "Default TS", new DateTime(2025, 1, 1, 12, 0, 0), chunks, camEvent);
 
         vm.Playback.HasEventMarker.ShouldBeFalse();
     }
@@ -51,7 +51,7 @@ public void EventMarker_AtTheVeryStart_ShowsAtFractionZero()
         var vm = CreateViewModel();
 
         // Event fired on the first recorded frame (timestamp == first chunk's timestamp): fraction is exactly 0, which is a real position, not clock skew.
-        vm.SelectedClip = ClipWithChunksAndEvent(10, TimeSpan.Zero);
+        vm.Library.SelectedClip = ClipWithChunksAndEvent(10, TimeSpan.Zero);
 
         vm.Playback.HasEventMarker.ShouldBeTrue();
         vm.Playback.EventMarkerPosition.ShouldBe(0);
@@ -63,7 +63,7 @@ public void EventMarker_AbsentWhenEventBeforeClipStart()
         var vm = CreateViewModel();
 
         // Clock skew: event five minutes before the first chunk -> fraction <= 0, no marker.
-        vm.SelectedClip = ClipWithChunksAndEvent(10, TimeSpan.FromMinutes(-5));
+        vm.Library.SelectedClip = ClipWithChunksAndEvent(10, TimeSpan.FromMinutes(-5));
 
         vm.Playback.HasEventMarker.ShouldBeFalse();
     }
@@ -74,7 +74,7 @@ public void EventMarker_AbsentWhenEventBeyondModeledDuration()
         var vm = CreateViewModel();
 
         // 3 chunks = 180s modeled; an event at 200s is past the estimated end (fraction > 1).
-        vm.SelectedClip = ClipWithChunksAndEvent(3, TimeSpan.FromSeconds(200));
+        vm.Library.SelectedClip = ClipWithChunksAndEvent(3, TimeSpan.FromSeconds(200));
 
         vm.Playback.HasEventMarker.ShouldBeFalse();
     }
@@ -85,7 +85,7 @@ public void EventMarker_AbsentWhenNoChunks_NoDivideByZero()
         var vm = CreateViewModel();
         var camEvent = new CamEvent { Reason = "user_interaction_honk", Timestamp = new DateTime(2025, 1, 1, 12, 5, 0) };
 
-        vm.SelectedClip = new CamClip(System.IO.Path.GetTempPath(), "No Chunks", new DateTime(2025, 1, 1, 12, 0, 0), [], camEvent);
+        vm.Library.SelectedClip = new CamClip(System.IO.Path.GetTempPath(), "No Chunks", new DateTime(2025, 1, 1, 12, 0, 0), [], camEvent);
 
         vm.Playback.HasEventMarker.ShouldBeFalse();
         vm.Playback.EventMarkerPosition.ShouldBe(0);
@@ -97,7 +97,7 @@ public void ChunkBoundaries_AreInteriorFractions()
     {
         var vm = CreateViewModel();
 
-        vm.SelectedClip = ClipWithChunks(3);
+        vm.Library.SelectedClip = ClipWithChunks(3);
 
         vm.Playback.ChunkBoundaries.Count.ShouldBe(2);
         vm.Playback.ChunkBoundaries[0].ShouldBe(1.0 / 3, 0.0001);
@@ -109,7 +109,7 @@ public void ChunkBoundaries_EmptyForSingleChunk()
     {
         var vm = CreateViewModel();
 
-        vm.SelectedClip = ClipWithChunks(1);
+        vm.Library.SelectedClip = ClipWithChunks(1);
 
         vm.Playback.ChunkBoundaries.ShouldBeEmpty();
     }
@@ -122,7 +122,7 @@ public void GapPositions_EmptyBeforeMediaOpens()
         // No controller at all: RecomputeSelectedClipTimeline can only fall back to the estimate, which carries no gap information.
         var vm = CreateViewModel();
 
-        vm.SelectedClip = ClipWithChunksAndEvent(3, TimeSpan.FromSeconds(90));
+        vm.Library.SelectedClip = ClipWithChunksAndEvent(3, TimeSpan.FromSeconds(90));
 
         vm.Playback.GapPositions.ShouldBeEmpty();
     }
@@ -137,7 +137,7 @@ public void GapPositions_ReflectAGapOnceMediaSourceIsOpen()
         var clip = new CamClip(clipFiles.Clip.FullPath, clipFiles.Clip.Name, clipFiles.Clip.Timestamp, chunks, camEvent: null);
 
         var (vm, _, _) = CreateViewModelWithOpenedClip(clip);
-        vm.SelectedClip = clip;
+        vm.Library.SelectedClip = clip;
 
         // Two included chunks of 60s each = 120s total; the single gap sits at media time 60s.
         vm.Playback.GapPositions.ShouldBe([60.0 / 120], 0.0001);
@@ -155,7 +155,7 @@ public void EventMarker_AfterAGap_UsesGapCorrectedFraction_NotLinearTime()
         var clip = new CamClip(clipFiles.Clip.FullPath, clipFiles.Clip.Name, clipFiles.Clip.Timestamp, chunks, camEvent);
 
         var (vm, _, _) = CreateViewModelWithOpenedClip(clip);
-        vm.SelectedClip = clip;
+        vm.Library.SelectedClip = clip;
 
         vm.Playback.HasEventMarker.ShouldBeTrue();
         vm.Playback.EventMarkerPosition.ShouldBe(70.0 / 120, 0.0001);
@@ -168,10 +168,10 @@ public void EventMarker_AfterAGap_UsesGapCorrectedFraction_NotLinearTime()
     public void ClearingSelection_ResetsEventMarkerAndChunks()
     {
         var vm = CreateViewModel();
-        vm.SelectedClip = ClipWithChunksAndEvent(10, TimeSpan.FromSeconds(570));
+        vm.Library.SelectedClip = ClipWithChunksAndEvent(10, TimeSpan.FromSeconds(570));
         vm.Playback.HasEventMarker.ShouldBeTrue();
 
-        vm.SelectedClip = null;
+        vm.Library.SelectedClip = null;
 
         vm.Playback.HasEventMarker.ShouldBeFalse();
         vm.Playback.EventMarkerPosition.ShouldBe(0);
@@ -184,7 +184,7 @@ public void JumpToEvent_CanExecute_FollowsHasEventMarker()
         var vm = CreateViewModel();
         vm.Playback.JumpToEventCommand.CanExecute(null).ShouldBeFalse();
 
-        vm.SelectedClip = ClipWithChunksAndEvent(10, TimeSpan.FromSeconds(570));
+        vm.Library.SelectedClip = ClipWithChunksAndEvent(10, TimeSpan.FromSeconds(570));
 
         vm.Playback.JumpToEventCommand.CanExecute(null).ShouldBeTrue();
     }
@@ -201,7 +201,7 @@ public void EventShortcut_WithAnOpenedEventClip_SeeksThePlayersToTheEventMoment(
             clipFiles.Clip.Chunks,
             new CamEvent { Timestamp = clipFiles.Clip.Chunks[1].Timestamp.AddSeconds(30) });
         var (vm, controller, front) = CreateViewModelWithOpenedClip(clip);
-        vm.SelectedClip = clip;
+        vm.Library.SelectedClip = clip;
 
         var handled = vm.HandleKeyDown(Key.E, ModifierKeys.None);
         RunPinnedToTestThread(controller.WhenIdleAsync);
@@ -216,7 +216,7 @@ public void EventShortcut_WithAnOpenedEventClip_SeeksThePlayersToTheEventMoment(
     public async Task EventShortcut_Ignored_WhenNoMarker()
     {
         var vm = CreateViewModel();
-        vm.SelectedClip = ClipWithChunks(3); // no event
+        vm.Library.SelectedClip = ClipWithChunks(3); // no event
 
         var handled = await vm.HandleKeyDownAsync(Key.E, ModifierKeys.None);
 
@@ -230,7 +230,7 @@ public void SelectingClip_RaisesEventMarkerNotifications()
         var changed = new List<string>();
         vm.Playback.PropertyChanged += (_, e) => changed.Add(e.PropertyName);
 
-        vm.SelectedClip = ClipWithChunksAndEvent(5, TimeSpan.FromSeconds(250));
+        vm.Library.SelectedClip = ClipWithChunksAndEvent(5, TimeSpan.FromSeconds(250));
 
         changed.ShouldContain(nameof(PlaybackViewModel.EventMarkerPosition));
         changed.ShouldContain(nameof(PlaybackViewModel.HasEventMarker));
diff --git a/SentryDeck.Tests/MainWindowViewModelTests.Playback.cs b/SentryDeck.Tests/MainWindowViewModelTests.Playback.cs
index 5cfd90b..6d93b77 100644
--- a/SentryDeck.Tests/MainWindowViewModelTests.Playback.cs
+++ b/SentryDeck.Tests/MainWindowViewModelTests.Playback.cs
@@ -180,7 +180,7 @@ public void SelectingClip_NotYetOpened_ShowsLoadingWithoutAnError()
         var clip = TestClips.Create(1)[0];
         var vm = CreateViewModelWithController(out _, out _);
 
-        vm.SelectedClip = clip;
+        vm.Library.SelectedClip = clip;
 
         // Selecting a clip runs OnSelectedClipChanged -> PlaySelectedClipAsync, which sets IsLoading=true (synchronously, before the awaited yield) and calls the controller.
         // The clip is intentionally NOT in the controller's playlist, so GoToClipAsync is a deterministic no-op; this verifies only that selection triggers the auto-play loading state.
@@ -196,7 +196,7 @@ public void SelectingAnEventClip_AutoFocusesTheTriggeringCamera()
 
         // Camera id 7 is the rear camera.
         // As in SelectingClip_TriggersPlaybackLoading, the clip is deliberately not in the controller's playlist, so GoToClipAsync early-returns and the rest of the selection load runs inline on this thread.
-        vm.SelectedClip = ClipWithCamerasAndEventCamera(eventCamera: 7, SixCameras);
+        vm.Library.SelectedClip = ClipWithCamerasAndEventCamera(eventCamera: 7, SixCameras);
 
         // Opening an incident on the angle that triggered it is the whole point of the metadata.
         vm.Cameras.SelectedCameraView.ShouldBe(CameraNames.Back);
@@ -214,7 +214,7 @@ public void StopCommand_WhileASelectionIsWaitingToLoad_KeepsItFromPlaying()
         var vm = new MainWindowViewModel(() => controller, backgroundYield: () => loadGate.Task);
         vm.InitializePlayer();
 
-        vm.SelectedClip = clipFiles.Clip;
+        vm.Library.SelectedClip = clipFiles.Clip;
         RunPinnedToTestThread(() => vm.Playback.StopCommand.ExecuteAsync(null));
         loadGate.SetResult();
         RunPinnedToTestThread(controller.WhenIdleAsync);
diff --git a/SentryDeck.Tests/MainWindowViewModelTests.Trimming.cs b/SentryDeck.Tests/MainWindowViewModelTests.Trimming.cs
index 68f1097..581cfb2 100644
--- a/SentryDeck.Tests/MainWindowViewModelTests.Trimming.cs
+++ b/SentryDeck.Tests/MainWindowViewModelTests.Trimming.cs
@@ -84,7 +84,7 @@ public void Selection_ClearsWhenAnotherClipIsSelected()
         vm.Playback.SeekPosition = 0.2;
         vm.MarkSelectionStartCommand.Execute(null);
 
-        vm.SelectedClip = TestClips.Create(1)[0];
+        vm.Library.SelectedClip = TestClips.Create(1)[0];
 
         vm.HasAnySelectionMark.ShouldBeFalse();
     }
@@ -172,7 +172,7 @@ public void TrimPanel_ClosesWhenAnotherClipIsSelected()
         controller.IsMediaOpen = true;
 
         vm.ToggleTrimmingCommand.Execute(null);
-        vm.SelectedClip = TestClips.Create(1)[0];
+        vm.Library.SelectedClip = TestClips.Create(1)[0];
 
         vm.IsTrimming.ShouldBeFalse();
     }
diff --git a/SentryDeck.Tests/MainWindowViewModelTests.cs b/SentryDeck.Tests/MainWindowViewModelTests.cs
index 56aea92..2d3ba1a 100644
--- a/SentryDeck.Tests/MainWindowViewModelTests.cs
+++ b/SentryDeck.Tests/MainWindowViewModelTests.cs
@@ -241,7 +241,7 @@ public void SixCameraClip_OffersPillarTiles_InCanonicalOrder()
     {
         var vm = CreateViewModel();
 
-        vm.SelectedClip = ClipWithCameras(SixCameras);
+        vm.Library.SelectedClip = ClipWithCameras(SixCameras);
 
         vm.Cameras.CameraViewOptions.Select(option => option.ViewId).ShouldBe(
             [
@@ -266,7 +266,7 @@ public void FourCameraClip_DoesNotOfferPillarTiles_AndPillarSelectionFallsBackTo
     {
         var vm = CreateViewModel();
 
-        vm.SelectedClip = ClipWithCameras(CameraNames.Front, CameraNames.Back, CameraNames.LeftRepeater, CameraNames.RightRepeater);
+        vm.Library.SelectedClip = ClipWithCameras(CameraNames.Front, CameraNames.Back, CameraNames.LeftRepeater, CameraNames.RightRepeater);
 
         vm.Cameras.CameraViewOptions.Count.ShouldBe(5);
         vm.Cameras.CameraViewOptions.ShouldAllBe(option => option.ViewId != CameraNames.LeftPillar);
@@ -279,10 +279,10 @@ public void FourCameraClip_DoesNotOfferPillarTiles_AndPillarSelectionFallsBackTo
     public void SwitchingToClipWithoutTheWatchedCamera_FallsBackToFront()
     {
         var vm = CreateViewModel();
-        vm.SelectedClip = ClipWithCameras(SixCameras);
+        vm.Library.SelectedClip = ClipWithCameras(SixCameras);
         vm.Cameras.SelectCameraViewCommand.Execute(CameraNames.RightPillar);
 
-        vm.SelectedClip = ClipWithCameras(CameraNames.Front, CameraNames.Back, CameraNames.LeftRepeater, CameraNames.RightRepeater);
+        vm.Library.SelectedClip = ClipWithCameras(CameraNames.Front, CameraNames.Back, CameraNames.LeftRepeater, CameraNames.RightRepeater);
 
         vm.Cameras.SelectedCameraView.ShouldBe(CameraNames.Front);
     }
@@ -291,10 +291,10 @@ public void SwitchingToClipWithoutTheWatchedCamera_FallsBackToFront()
     public void SwitchingClips_KeepsTheWatchedCamera_WhenTheNewClipHasIt()
     {
         var vm = CreateViewModel();
-        vm.SelectedClip = ClipWithCameras(SixCameras);
+        vm.Library.SelectedClip = ClipWithCameras(SixCameras);
         vm.Cameras.SelectCameraViewCommand.Execute(CameraNames.LeftPillar);
 
-        vm.SelectedClip = ClipWithCameras(SixCameras);
+        vm.Library.SelectedClip = ClipWithCameras(SixCameras);
 
         vm.Cameras.SelectedCameraView.ShouldBe(CameraNames.LeftPillar);
         vm.Cameras.CameraViewOptions.Single(option => option.IsSelected).ViewId.ShouldBe(CameraNames.LeftPillar);
@@ -312,7 +312,7 @@ public void SwitchingClips_KeepsTheWatchedCamera_WhenTheNewClipHasIt()
     public void CameraIdToView_MapsDocumentedEventCameraIds(int cameraId, string expectedView)
     {
         var vm = CreateViewModel();
-        vm.SelectedClip = ClipWithCameras(SixCameras);
+        vm.Library.SelectedClip = ClipWithCameras(SixCameras);
 
         vm.Cameras.CameraIdToView(cameraId).ShouldBe(expectedView);
     }
@@ -321,7 +321,7 @@ public void CameraIdToView_MapsDocumentedEventCameraIds(int cameraId, string exp
     public void CameraIdToView_FallsBackToFront_WhenTheClipLacksThatCamera()
     {
         var vm = CreateViewModel();
-        vm.SelectedClip = ClipWithCameras(CameraNames.Front, CameraNames.Back, CameraNames.LeftRepeater, CameraNames.RightRepeater);
+        vm.Library.SelectedClip = ClipWithCameras(CameraNames.Front, CameraNames.Back, CameraNames.LeftRepeater, CameraNames.RightRepeater);
 
         vm.Cameras.CameraIdToView(5).ShouldBe(CameraNames.Front);
         vm.Cameras.CameraIdToView(7).ShouldBe(CameraNames.Back);
@@ -331,7 +331,7 @@ public void CameraIdToView_FallsBackToFront_WhenTheClipLacksThatCamera()
     public async Task NumberKeys_SelectTilesByStripPosition_IncludingPillars()
     {
         var vm = CreateViewModel();
-        vm.SelectedClip = ClipWithCameras(SixCameras);
+        vm.Library.SelectedClip = ClipWithCameras(SixCameras);
 
         (await vm.HandleKeyDownAsync(Key.D6, ModifierKeys.None)).ShouldBeTrue();
         vm.Cameras.SelectedCameraView.ShouldBe(CameraNames.LeftPillar);
@@ -408,7 +408,7 @@ public void SelectingClip_HidesOverlay_AndShowsVideo()
     {
         var vm = CreateViewModel();
 
-        vm.SelectedClip = TestClips.Create(1)[0];
+        vm.Library.SelectedClip = TestClips.Create(1)[0];
 
         vm.HasNoClipSelected.ShouldBeFalse();
         vm.ShowStatusOverlay.ShouldBeFalse();
@@ -421,7 +421,7 @@ public void CanPlayPause_RequiresClipOrPlayback_AndNotLoading()
         var vm = CreateViewModel();
         vm.Playback.CanPlayPause.ShouldBeFalse();
 
-        vm.SelectedClip = TestClips.Create(1)[0];
+        vm.Library.SelectedClip = TestClips.Create(1)[0];
         vm.Playback.CanPlayPause.ShouldBeTrue();
 
         vm.Playback.IsLoading = true;
@@ -429,7 +429,7 @@ public void CanPlayPause_RequiresClipOrPlayback_AndNotLoading()
 
         // Even with no selected clip, an in-flight playback keeps the toggle live.
         vm.Playback.IsLoading = false;
-        vm.SelectedClip = null;
+        vm.Library.SelectedClip = null;
         vm.Playback.IsPlaying = true;
         vm.Playback.CanPlayPause.ShouldBeTrue();
     }
diff --git a/SentryDeck/MainWindow.xaml b/SentryDeck/MainWindow.xaml
index 05895a8..9ad4bd2 100644
--- a/SentryDeck/MainWindow.xaml
+++ b/SentryDeck/MainWindow.xaml
@@ -217,19 +217,19 @@
                                     <Style TargetType="Border">
                                         <Setter Property="Background" Value="{DynamicResource TextFillColorTertiaryBrush}" />
                                         <Style.Triggers>
-                                            <DataTrigger Binding="{Binding Data.SelectedClip.Event, Converter={local:ReasonKeyConverter}, Source={StaticResource VmProxy}}"
+                                            <DataTrigger Binding="{Binding Data.Library.SelectedClip.Event, Converter={local:ReasonKeyConverter}, Source={StaticResource VmProxy}}"
                                                          Value="sentry">
                                                 <Setter Property="Background" Value="{DynamicResource SystemFillColorAttentionBrush}" />
                                             </DataTrigger>
-                                            <DataTrigger Binding="{Binding Data.SelectedClip.Event, Converter={local:ReasonKeyConverter}, Source={StaticResource VmProxy}}"
+                                            <DataTrigger Binding="{Binding Data.Library.SelectedClip.Event, Converter={local:ReasonKeyConverter}, Source={StaticResource VmProxy}}"
                                                          Value="honk">
                                                 <Setter Property="Background" Value="{DynamicResource SystemFillColorCautionBrush}" />
                                             </DataTrigger>
-                                            <DataTrigger Binding="{Binding Data.SelectedClip.Event, Converter={local:ReasonKeyConverter}, Source={StaticResource VmProxy}}"
+                                            <DataTrigger Binding="{Binding Data.Library.SelectedClip.Event, Converter={local:ReasonKeyConverter}, Source={StaticResource VmProxy}}"
                                                          Value="alert">
                                                 <Setter Property="Background" Value="{DynamicResource SystemFillColorCriticalBrush}" />
                                             </DataTrigger>
-                                            <DataTrigger Binding="{Binding Data.SelectedClip.Event, Converter={local:ReasonKeyConverter}, Source={StaticResource VmProxy}}"
+                                            <DataTrigger Binding="{Binding Data.Library.SelectedClip.Event, Converter={local:ReasonKeyConverter}, Source={StaticResource VmProxy}}"
                                                          Value="saved">
                                                 <Setter Property="Background" Value="{DynamicResource AccentFillColorDefaultBrush}" />
                                             </DataTrigger>
@@ -480,7 +480,7 @@
 
         <!--  Day-grouped clip view; grouping lives in XAML via the shared VmProxy above.  -->
         <CollectionViewSource x:Key="GroupedClips"
-                              Source="{Binding Data.FilteredClips, Source={StaticResource VmProxy}}">
+                              Source="{Binding Data.Library.FilteredClips, Source={StaticResource VmProxy}}">
             <CollectionViewSource.GroupDescriptions>
                 <PropertyGroupDescription Converter="{local:DateOnlyConverter}"
                                           PropertyName="Timestamp" />
@@ -490,14 +490,14 @@
         <!--  Shared clip context menu (Tag on the item = the view-model).  -->
         <ContextMenu x:Key="ClipContextMenu">
             <MenuItem Header="Open clip folder"
-                      Command="{Binding PlacementTarget.Tag.OpenClipFolderCommand, RelativeSource={RelativeSource AncestorType=ContextMenu}}"
+                      Command="{Binding PlacementTarget.Tag.Library.OpenClipFolderCommand, RelativeSource={RelativeSource AncestorType=ContextMenu}}"
                       CommandParameter="{Binding PlacementTarget.DataContext, RelativeSource={RelativeSource AncestorType=ContextMenu}}">
                 <MenuItem.Icon>
                     <TextBlock Text="&#xE8B7;" Style="{StaticResource AppGlyph}" />
                 </MenuItem.Icon>
             </MenuItem>
             <MenuItem Header="Show on map"
-                      Command="{Binding PlacementTarget.Tag.ShowOnMapCommand, RelativeSource={RelativeSource AncestorType=ContextMenu}}"
+                      Command="{Binding PlacementTarget.Tag.Library.ShowOnMapCommand, RelativeSource={RelativeSource AncestorType=ContextMenu}}"
                       CommandParameter="{Binding PlacementTarget.DataContext, RelativeSource={RelativeSource AncestorType=ContextMenu}}">
                 <MenuItem.Icon>
                     <TextBlock Text="&#xECAF;" Style="{StaticResource AppGlyph}" />
@@ -513,21 +513,21 @@
             </MenuItem>
             <Separator />
             <MenuItem Header="Copy clip name"
-                      Command="{Binding PlacementTarget.Tag.CopyClipNameCommand, RelativeSource={RelativeSource AncestorType=ContextMenu}}"
+                      Command="{Binding PlacementTarget.Tag.Library.CopyClipNameCommand, RelativeSource={RelativeSource AncestorType=ContextMenu}}"
                       CommandParameter="{Binding PlacementTarget.DataContext, RelativeSource={RelativeSource AncestorType=ContextMenu}}">
                 <MenuItem.Icon>
                     <TextBlock Text="&#xE8C8;" Style="{StaticResource AppGlyph}" />
                 </MenuItem.Icon>
             </MenuItem>
             <MenuItem Header="Copy timestamp"
-                      Command="{Binding PlacementTarget.Tag.CopyTimestampCommand, RelativeSource={RelativeSource AncestorType=ContextMenu}}"
+                      Command="{Binding PlacementTarget.Tag.Library.CopyTimestampCommand, RelativeSource={RelativeSource AncestorType=ContextMenu}}"
                       CommandParameter="{Binding PlacementTarget.DataContext, RelativeSource={RelativeSource AncestorType=ContextMenu}}">
                 <MenuItem.Icon>
                     <TextBlock Text="&#xE8C8;" Style="{StaticResource AppGlyph}" />
                 </MenuItem.Icon>
             </MenuItem>
             <MenuItem Header="Copy folder path"
-                      Command="{Binding PlacementTarget.Tag.CopyClipPathCommand, RelativeSource={RelativeSource AncestorType=ContextMenu}}"
+                      Command="{Binding PlacementTarget.Tag.Library.CopyClipPathCommand, RelativeSource={RelativeSource AncestorType=ContextMenu}}"
                       CommandParameter="{Binding PlacementTarget.DataContext, RelativeSource={RelativeSource AncestorType=ContextMenu}}">
                 <MenuItem.Icon>
                     <TextBlock Text="&#xE8C8;" Style="{StaticResource AppGlyph}" />
@@ -536,7 +536,7 @@
             <Separator />
             <!--  Moves the whole clip folder to the Windows Recycle Bin (recoverable) so the timeline can be tidied in place.  -->
             <MenuItem Header="Delete to Recycle Bin"
-                      Command="{Binding PlacementTarget.Tag.DeleteClipCommand, RelativeSource={RelativeSource AncestorType=ContextMenu}}"
+                      Command="{Binding PlacementTarget.Tag.Library.DeleteClipCommand, RelativeSource={RelativeSource AncestorType=ContextMenu}}"
                       CommandParameter="{Binding PlacementTarget.DataContext, RelativeSource={RelativeSource AncestorType=ContextMenu}}">
                 <MenuItem.Icon>
                     <TextBlock Text="&#xE74D;" Style="{StaticResource AppGlyph}" />
@@ -607,7 +607,7 @@
 
                         <Grid Grid.Column="1">
                             <TextBox x:Name="SearchBox"
-                                     Text="{Binding FilterText, UpdateSourceTrigger=PropertyChanged}"
+                                     Text="{Binding Library.FilterText, UpdateSourceTrigger=PropertyChanged}"
                                      Padding="10,8,8,8"
                                      VerticalContentAlignment="Center"
                                      FontSize="14"
@@ -625,7 +625,7 @@
                                     <Style TargetType="TextBlock">
                                         <Setter Property="Visibility" Value="Hidden" />
                                         <Style.Triggers>
-                                            <DataTrigger Binding="{Binding FilterText}"
+                                            <DataTrigger Binding="{Binding Library.FilterText}"
                                                          Value="">
                                                 <Setter Property="Visibility" Value="Visible" />
                                             </DataTrigger>
@@ -649,7 +649,7 @@
                          PreviewMouseLeftButtonUp="ClipListBox_PreviewMouseLeftButtonUp"
                          PreviewMouseRightButtonDown="ClipListBox_PreviewMouseRightButtonDown"
                          ScrollViewer.HorizontalScrollBarVisibility="Disabled"
-                         SelectedItem="{Binding SelectedClip, Mode=TwoWay}"
+                         SelectedItem="{Binding Library.SelectedClip, Mode=TwoWay}"
                          VirtualizingPanel.IsVirtualizingWhenGrouping="True"
                          VirtualizingPanel.VirtualizationMode="Recycling">
                     <ListBox.GroupStyle>
@@ -862,9 +862,9 @@
                             <Style.Triggers>
                                 <MultiDataTrigger>
                                     <MultiDataTrigger.Conditions>
-                                        <Condition Binding="{Binding ClipCount}" Value="0" />
-                                        <Condition Binding="{Binding IsLoadingClips}" Value="False" />
-                                        <Condition Binding="{Binding HasFilterText}" Value="True" />
+                                        <Condition Binding="{Binding Library.ClipCount}" Value="0" />
+                                        <Condition Binding="{Binding Library.IsLoadingClips}" Value="False" />
+                                        <Condition Binding="{Binding Library.HasFilterText}" Value="True" />
                                     </MultiDataTrigger.Conditions>
                                     <Setter Property="Visibility" Value="Visible" />
                                 </MultiDataTrigger>
@@ -893,7 +893,7 @@
                              Background="Transparent"
                              BorderThickness="0"
                              IsIndeterminate="True"
-                             Visibility="{Binding IsLoadingClips, Converter={local:BoolToVisibilityConverter}}" />
+                             Visibility="{Binding Library.IsLoadingClips, Converter={local:BoolToVisibilityConverter}}" />
 
                 <!--  Utility action bar (single row, divided from the list)  -->
                 <Border Grid.Row="2"
@@ -910,7 +910,7 @@
                         </Grid.ColumnDefinitions>
 
                         <Button Grid.Column="0"
-                                Command="{Binding OpenFolderCommand}"
+                                Command="{Binding Library.OpenFolderCommand}"
                                 HorizontalContentAlignment="Left"
                                 AutomationProperties.Name="Select folder"
                                 Style="{StaticResource PressScaleButton}">
@@ -924,7 +924,7 @@
                         </Button>
 
                         <Button Grid.Column="2"
-                                Command="{Binding RefreshClipsCommand}"
+                                Command="{Binding Library.RefreshClipsCommand}"
                                 AutomationProperties.Name="Rescan folder"
                                 Style="{StaticResource SubtleIconButton}"
                                 ToolTip="Rescan the current folder for clips">
@@ -1306,7 +1306,7 @@
                                            TextAlignment="Center"
                                            TextWrapping="Wrap" />
                                 <Button Content="Select folder"
-                                        Command="{Binding OpenFolderCommand}"
+                                        Command="{Binding Library.OpenFolderCommand}"
                                         Margin="0,20,0,0"
                                         Padding="24,8"
                                         HorizontalAlignment="Center"
diff --git a/SentryDeck/MainWindowViewModel.cs b/SentryDeck/MainWindowViewModel.cs
index 2ed9e02..9685710 100644
--- a/SentryDeck/MainWindowViewModel.cs
+++ b/SentryDeck/MainWindowViewModel.cs
@@ -19,21 +19,14 @@ namespace SentryDeck;
 /// </summary>
 public partial class MainWindowViewModel : ObservableObject
 {
-    private readonly List<CamClip> _allClips = [];
     private readonly FlyleafRuntime _flyleafRuntime = new();
-    private readonly Func<string, IReadOnlyList<CamClip>> _clipLoader;
     private readonly Dispatcher _dispatcher;
-    private readonly DispatcherTimer _filterDebounceTimer;
     private readonly IClipExporter _clipExporter;
     private readonly Func<string, string> _savePathPicker;
     private readonly IClipMediaSourceBuilder _exportMediaSourceBuilder;
     private bool _isInitialized;
     private bool _isDownloadingFFmpeg;
 
-    // The source of dashcam roots: auto-discovery by default, or the user's last picked folders.
-    // Refresh re-evaluates it to rescan for newly added clips (and, for auto-discovery, newly connected drives).
-    private Func<IEnumerable<string>> _rootSource = CamStorage.FindCommonRoots;
-
     /// <param name="playerControllerFactory">Creates the playback controller (the view supplies one bound to its Flyleaf hosts).</param> <param name="clipLoader">Maps a dashcam root to its clips.
     /// Defaults to scanning the filesystem; overridable for tests.</param> <param name="backgroundYield">Yields to the UI before a clip loads so the window stays responsive.
     /// Overridable for tests.</param> <param name="clipExporter">Exports trimmed clip ranges.
@@ -50,7 +43,6 @@ public MainWindowViewModel(
         IClipMediaSourceBuilder exportMediaSourceBuilder = null,
         Action<Action> uiInvoker = null)
     {
-        _clipLoader = clipLoader ?? (root => CamStorage.Map(root).Clips);
         _clipExporter = clipExporter ?? new ClipExporter(PackageManager.FindFFmpegDirectory);
         _savePathPicker = savePathPicker ?? PickSavePathWithDialog;
         _exportMediaSourceBuilder = exportMediaSourceBuilder ?? new FfconcatMediaSourceBuilder();
@@ -61,13 +53,11 @@ public MainWindowViewModel(
             uiInvoker ?? InvokeOnDispatcher,
             Error,
             Cameras);
-
-        // Coalesces the expensive clip-list regroup/rebind so fast typing in search stays smooth; the getters stay live, so only the (debounced) change notification is deferred.
-        _filterDebounceTimer = new DispatcherTimer(DispatcherPriority.Background, _dispatcher)
-        {
-            Interval = TimeSpan.FromMilliseconds(150),
-        };
-        _filterDebounceTimer.Tick += OnFilterDebounceTick;
+        Library = new ClipLibraryViewModel(
+            clipLoader ?? (root => CamStorage.Map(root).Clips),
+            Playback,
+            Error,
+            _dispatcher);
 
         Error.PropertyChanged += (_, e) =>
         {
@@ -81,7 +71,8 @@ public MainWindowViewModel(
         };
 
         Playback.PropertyChanged += OnPlaybackPropertyChanged;
-        Playback.CurrentClipChanged += (_, clip) => SelectedClip = clip;
+        Playback.CurrentClipChanged += (_, clip) => Library.SelectedClip = clip;
+        Library.PropertyChanged += OnLibraryPropertyChanged;
     }
 
     /// <summary>
@@ -109,63 +100,27 @@ public MainWindowViewModel(
     /// </summary>
     public PlaybackViewModel Playback { get; }
 
-    public bool ShowMainContent => !ShowAboutPage;
-
-    public IReadOnlyList<CamClip> FilteredClips => _allClips
-        .Where(MatchesFilter)
-        .OrderByDescending(c => c.Timestamp)
-        .ThenBy(c => c.Name)
-        .ToList();
-
-    /// <summary>Number of clips currently shown (drives the sidebar count).</summary>
-    public int ClipCount => FilteredClips.Count;
-
-    /// <summary>True when the search box has text (drives the clear button).</summary>
-    public bool HasFilterText => !string.IsNullOrEmpty(FilterText);
-
-    // Matches the clip name, path, event city, and friendly event reason (e.g. "sentry", "honk", "saved").
-    private bool MatchesFilter(CamClip clip)
-    {
-        if (string.IsNullOrWhiteSpace(FilterText))
-        {
-            return true;
-        }
-
-        var term = FilterText;
-        return clip.Name.Contains(term, StringComparison.CurrentCultureIgnoreCase)
-            || clip.FullPath.Contains(term, StringComparison.CurrentCultureIgnoreCase)
-            || (clip.Event?.City?.Contains(term, StringComparison.CurrentCultureIgnoreCase) ?? false)
-            || ClipDisplay.ReasonLabel(clip.Event).Contains(term, StringComparison.CurrentCultureIgnoreCase);
-    }
-
-    // Restart the debounce on each keystroke; the list is rebound once typing settles.
-    partial void OnFilterTextChanged(string value)
-    {
-        _filterDebounceTimer.Stop();
-        _filterDebounceTimer.Start();
-    }
+    /// <summary>
+    /// The clip list: scanning, search, the selected clip, and per-clip actions.
+    /// </summary>
+    public ClipLibraryViewModel Library { get; }
 
-    private void OnFilterDebounceTick(object sender, EventArgs e)
-    {
-        _filterDebounceTimer.Stop();
-        OnPropertyChanged(nameof(FilteredClips));
-        OnPropertyChanged(nameof(ClipCount));
-    }
+    public bool ShowMainContent => !ShowAboutPage;
 
     // The full-screen overlay only covers the no-video states (scanning with no clip, error, empty); as a WPF sibling it can't draw over the Flyleaf video surface anyway.
     // While a selected clip loads, the hosts stay visible and simply show black until the first frame decodes, with no loading screen flashing mid-playback.
-    public bool ShowStatusOverlay => (IsLoading && SelectedClip is null) || Error.IsVisible || HasNoClipSelected;
+    public bool ShowStatusOverlay => (IsLoading && Library.SelectedClip is null) || Error.IsVisible || HasNoClipSelected;
 
     /// <summary>
     /// True while anything blocks the video pane: a clip scan, the FFmpeg download, or the selected clip loading.
     /// </summary>
-    public bool IsLoading => IsLoadingClips || _isDownloadingFFmpeg || Playback.IsLoading;
+    public bool IsLoading => Library.IsLoadingClips || _isDownloadingFFmpeg || Playback.IsLoading;
 
-    public bool ShowVideoHosts => SelectedClip is not null && !Error.IsVisible;
+    public bool ShowVideoHosts => Library.SelectedClip is not null && !Error.IsVisible;
 
     public bool HasError => Error.IsVisible;
 
-    public bool HasNoClipSelected => SelectedClip is null && !IsLoading && !Error.IsVisible;
+    public bool HasNoClipSelected => Library.SelectedClip is null && !IsLoading && !Error.IsVisible;
 
     // --- Export selection (in/out marks on the seek bar, as 0..1 fractions like SeekPosition) ---
     // Plain fields + an explicit notify helper (not ObservableProperty) because the pair changes together under shared invariants (start < end) and several derived properties hang off both.
@@ -244,31 +199,10 @@ public string SelectionDurationText
     [NotifyCanExecuteChangedFor(nameof(SaveEventClipCommand))]
     private bool _isExporting;
 
-    // FilteredClips/ClipCount are refreshed on a short debounce (see OnFilterTextChanged) rather than per keystroke; HasFilterText stays immediate so the search box's clear affordance is responsive.
-    [ObservableProperty]
-    [NotifyPropertyChangedFor(nameof(HasFilterText))]
-    private string _filterText = string.Empty;
-
-    [ObservableProperty]
-    [NotifyPropertyChangedFor(nameof(HasNoClipSelected))]
-    [NotifyPropertyChangedFor(nameof(ShowStatusOverlay))]
-    [NotifyPropertyChangedFor(nameof(ShowVideoHosts))]
-    private CamClip _selectedClip;
-
     [ObservableProperty]
     [NotifyPropertyChangedFor(nameof(ShowMainContent))]
     private bool _showAboutPage;
 
-    // True while the clip list is being (re)scanned from disk; drives the sidebar loading indicator.
-    [ObservableProperty]
-    [NotifyPropertyChangedFor(nameof(IsLoading))]
-    [NotifyPropertyChangedFor(nameof(ShowStatusOverlay))]
-    [NotifyPropertyChangedFor(nameof(ShowVideoHosts))]
-    [NotifyPropertyChangedFor(nameof(HasNoClipSelected))]
-    [NotifyCanExecuteChangedFor(nameof(RefreshClipsCommand))]
-    [NotifyCanExecuteChangedFor(nameof(OpenFolderCommand))]
-    private bool _isLoadingClips;
-
     public async Task InitializeAsync()
     {
         if (_isInitialized)
@@ -286,7 +220,7 @@ public async Task InitializeAsync()
         if (_flyleafRuntime.TryStart())
         {
             InitializePlayer();
-            await LoadClipsAsync(_rootSource());
+            await Library.ReloadAsync();
         }
         else
         {
@@ -296,171 +230,12 @@ public async Task InitializeAsync()
 
     public void Shutdown()
     {
-        _filterDebounceTimer.Stop();
+        Library.Shutdown();
         Playback.Shutdown();
     }
 
     public void InitializePlayer() => Playback.InitializePlayer();
 
-    public async Task LoadClipsAsync(IEnumerable<string> roots, TimeSpan minimumLoadingDuration = default)
-    {
-        Error.Clear();
-        _allClips.Clear();
-        SelectedClip = null;
-        IsLoadingClips = true;
-
-        // Clear the list right away so a (re)scan visibly empties it and shows the loading bar before refilling.
-        OnPropertyChanged(nameof(FilteredClips));
-        OnPropertyChanged(nameof(ClipCount));
-        RefreshClipState();
-
-        var stopwatch = Stopwatch.StartNew();
-
-        try
-        {
-            // Scan the disk off the UI thread; the continuation resumes on it via the WPF SynchronizationContext, so all view-model state below is mutated on the UI thread.
-            var result = await Task.Run(() => ScanRoots(roots));
-
-            if (!result.HadRoots)
-            {
-                Error.Show(
-                    "No dashcam footage yet",
-                    "Point Sentry Deck at your TeslaCam folder to get started. Recorded USB drives are found automatically.",
-                    canDismiss: true,
-                    isEmptyState: true);
-            }
-            else
-            {
-                _allClips.AddRange(result.Clips);
-                foreach (var error in result.Errors)
-                {
-                    Error.Show(error.Title, error.Details);
-                }
-            }
-
-            Playback.SetPlaylist(_allClips);
-
-            // Hold the loading state briefly so a fast rescan still reads as a deliberate refresh (clear -> loading -> refill) instead of an imperceptible flicker.
-            var remaining = minimumLoadingDuration - stopwatch.Elapsed;
-            if (remaining > TimeSpan.Zero)
-            {
-                await Task.Delay(remaining);
-            }
-        }
-        finally
-        {
-            IsLoadingClips = false;
-            OnPropertyChanged(nameof(FilteredClips));
-            OnPropertyChanged(nameof(ClipCount));
-            RefreshClipState();
-        }
-    }
-
-    private ScanResult ScanRoots(IEnumerable<string> roots)
-    {
-        var rootList = roots?.Where(root => !string.IsNullOrWhiteSpace(root)).ToList() ?? [];
-        if (rootList.Count == 0)
-        {
-            Log.Information("No dashcam roots found");
-            return new ScanResult([], [], HadRoots: false);
-        }
-
-        Log.Information("Loading dashcam clips. RootCount={RootCount}; Roots={Roots}", rootList.Count, rootList);
-        var totalStopwatch = Stopwatch.StartNew();
-        var clips = new List<CamClip>();
-        var errors = new List<ClipLoadError>();
-
-        foreach (var root in rootList)
-        {
-            var rootStopwatch = Stopwatch.StartNew();
-            Log.Debug("Scanning dashcam root. Root={Root}", root);
-
-            try
-            {
-                var rootClips = _clipLoader(root);
-                clips.AddRange(rootClips);
-                Log.Information(
-                    "Scanned dashcam root. Root={Root}; ClipCount={ClipCount}; ElapsedMs={ElapsedMs}",
-                    root,
-                    rootClips.Count,
-                    rootStopwatch.ElapsedMilliseconds);
-            }
-            catch (UnauthorizedAccessException ex)
-            {
-                Log.Error(ex, "Access denied while loading dashcam root. Root={Root}", root);
-                errors.Add(new ClipLoadError("Access Denied", $"Cannot access folder: {root}\n\nCheck that you have permission to read this location."));
-            }
-            catch (Exception ex)
-            {
-                Log.Error(ex, "Failed to load dashcam root. Root={Root}", root);
-                errors.Add(new ClipLoadError("Error Loading Clips", $"Failed to load clips from:\n{root}\n\nError: {ex.Message}"));
-            }
-        }
-
-        Log.Information(
-            "Finished loading dashcam clips. ClipCount={ClipCount}; RootCount={RootCount}; FailedRootCount={FailedRootCount}; ElapsedMs={ElapsedMs}",
-            clips.Count,
-            rootList.Count,
-            errors.Count,
-            totalStopwatch.ElapsedMilliseconds);
-        return new ScanResult(clips, errors, HadRoots: true);
-    }
-
-    private sealed record ScanResult(IReadOnlyList<CamClip> Clips, IReadOnlyList<ClipLoadError> Errors, bool HadRoots);
-
-    private sealed record ClipLoadError(string Title, string Details);
-
-    private void RefreshClipState()
-    {
-        // FilteredClips is intentionally NOT raised here: this runs on every clip change, and re-notifying the unchanged list rebuilds the ListBox and retriggers its fade (flicker).
-        // The list is notified explicitly only when it actually changes (load + FilterText).
-        OnPropertyChanged(nameof(HasNoClipSelected));
-        OnPropertyChanged(nameof(ShowStatusOverlay));
-        OnPropertyChanged(nameof(ShowVideoHosts));
-    }
-
-    // Gated like Refresh: LoadClipsAsync has no re-entrancy protection, so picking a folder while a scan is still running would interleave two loads and merge both roots into one clip list.
-    [RelayCommand(CanExecute = nameof(CanRefreshClips))]
-    private async Task OpenFolderAsync()
-    {
-        Log.Debug("Opening folder picker");
-
-        var dialog = new OpenFolderDialog
-        {
-            Multiselect = true,
-            Title = "Select a folder containing Tesla dashcam footage (TeslaCam folder)",
-        };
-
-        if (dialog.ShowDialog() == true)
-        {
-            var folders = dialog.FolderNames;
-            Log.Information(
-                "User selected dashcam folders. FolderCount={FolderCount}; Folders={Folders}",
-                folders.Length,
-                folders);
-
-            await Playback.StopPlayerAsync();
-
-            _rootSource = () => folders;
-            await LoadClipsAsync(folders);
-        }
-        else
-        {
-            Log.Debug("Folder picker canceled");
-        }
-    }
-
-    [RelayCommand(CanExecute = nameof(CanRefreshClips))]
-    private async Task RefreshClipsAsync()
-    {
-        Log.Debug("Refreshing clips");
-
-        await Playback.StopPlayerAsync();
-        await LoadClipsAsync(_rootSource(), TimeSpan.FromMilliseconds(400));
-    }
-
-    private bool CanRefreshClips => !IsLoadingClips;
-
     /// <summary>
     /// Marks the selection start at the current playhead.
     /// A mark that would invert the range (start at or past the existing end) clears the other mark instead of silently swapping.
@@ -684,25 +459,6 @@ private static string PickSavePathWithDialog(string defaultFileName)
     internal Action<string> RevealInExplorer { get; set; } = path =>
         Process.Start(new ProcessStartInfo("explorer.exe", $"/select,\"{path}\"") { UseShellExecute = true });
 
-    /// <summary>
-    /// Asks the user to confirm sending a clip to the Recycle Bin.
-    /// Returns true to proceed.
-    /// Overridable for tests; defaults to a yes/no message box.
-    /// </summary>
-    internal Func<CamClip, bool> ConfirmDeleteClip { get; set; } = clip =>
-        MessageBox.Show(
-            $"Move this clip to the Recycle Bin?\n\n{clip.Name}\n{clip.FullPath}",
-            "Delete clip",
-            MessageBoxButton.YesNo,
-            MessageBoxImage.Warning) == MessageBoxResult.Yes;
-
-    /// <summary>
-    /// Sends a clip folder to the Windows Recycle Bin (recoverable).
-    /// Overridable for tests; defaults to the shell recycle operation, which surfaces its own error dialog if a file is in use.
-    /// </summary>
-    internal Action<string> RecycleClipFolder { get; set; } = path =>
-        FileSystem.DeleteDirectory(path, UIOption.OnlyErrorDialogs, RecycleOption.SendToRecycleBin);
-
     private static string FormatTimeSpanForFileName(TimeSpan ts) => FormatTimeSpan(ts).Replace(':', '.');
 
     private static string SanitizeFileName(string name)
@@ -728,7 +484,7 @@ private async Task DownloadFFmpegAsync()
             if (_flyleafRuntime.TryStart())
             {
                 InitializePlayer();
-                await LoadClipsAsync(_rootSource());
+                await Library.ReloadAsync();
             }
             else
             {
@@ -956,146 +712,39 @@ private void ToggleAbout()
         ShowAboutPage = !ShowAboutPage;
     }
 
-    [RelayCommand]
-    private void ClearFilter()
-    {
-        FilterText = string.Empty;
-    }
-
-    private static bool CanUseClip(CamClip clip)
-    {
-        return clip is not null;
-    }
-
-    [RelayCommand(CanExecute = nameof(CanUseClip))]
-    private void OpenClipFolder(CamClip clip)
-    {
-        if (clip is null)
-        {
-            return;
-        }
-
-        if (!Directory.Exists(clip.FullPath))
-        {
-            Error.Show("Clip Folder Not Found", $"Could not find folder:\n{clip.FullPath}");
-            return;
-        }
-
-        Process.Start(new ProcessStartInfo(clip.FullPath)
-        {
-            UseShellExecute = true,
-        });
-    }
-
-    [RelayCommand(CanExecute = nameof(CanUseClip))]
-    private void CopyClipPath(CamClip clip)
-    {
-        if (clip is not null)
-        {
-            Clipboard.SetText(clip.FullPath);
-        }
-    }
-
-    [RelayCommand(CanExecute = nameof(CanUseClip))]
-    private void CopyClipName(CamClip clip)
-    {
-        if (clip is not null)
-        {
-            Clipboard.SetText(clip.Name);
-        }
-    }
-
-    [RelayCommand(CanExecute = nameof(CanUseClip))]
-    private void CopyTimestamp(CamClip clip)
-    {
-        if (clip is not null)
-        {
-            // Invariant (24-hour, culture-stable) so the copied value matches the clip name and is paste-searchable, unlike the ambiguous AM/PM current-culture rendering.
-            Clipboard.SetText(clip.Timestamp.ToString(CultureInfo.InvariantCulture));
-        }
-    }
-
-    /// <summary>
-    /// Sends the clip's folder to the Recycle Bin so the timeline can be tidied without leaving the app.
-    /// Confirms first, then, if the clip is the one currently open, stops playback so Flyleaf releases its file handles before the shell tries to recycle the (otherwise locked) folder.
-    /// </summary>
-    [RelayCommand(CanExecute = nameof(CanUseClip))]
-    private async Task DeleteClipAsync(CamClip clip)
+    private void InvokeOnDispatcher(Action action)
     {
-        if (clip is null || !ConfirmDeleteClip(clip))
-        {
-            return;
-        }
-
-        // Flyleaf keeps the current clip's camera files open; Windows can't recycle a folder whose files are still locked, so stop and close the players before deleting it.
-        var isCurrent = ReferenceEquals(SelectedClip, clip)
-            || ReferenceEquals(Playback.NowPlayingClip, clip)
-            || Playback.CurrentClip == clip;
-        if (isCurrent && Playback.HasPlayer)
-        {
-            await Playback.StopPlayerAsync();
-            Playback.SeekPosition = 0;
-        }
-
-        try
-        {
-            Log.Information("Deleting clip to Recycle Bin. ClipName={ClipName}; ClipPath={ClipPath}", clip.Name, clip.FullPath);
-            await Task.Run(() => RecycleClipFolder(clip.FullPath));
-        }
-        catch (Exception ex)
+        if (_dispatcher.CheckAccess())
         {
-            Log.Error(ex, "Failed to delete clip. ClipName={ClipName}; ClipPath={ClipPath}", clip.Name, clip.FullPath);
-            Error.Show("Delete Failed", $"Could not delete clip: {clip.Name}\n\nError: {ex.Message}");
+            action();
             return;
         }
 
-        // Drop it from the sidebar list and keep the player's Next/Previous playlist in sync.
-        _allClips.Remove(clip);
-        Playback.RemoveFromPlaylist(clip);
-
-        if (ReferenceEquals(Playback.NowPlayingClip, clip))
-        {
-            Playback.NowPlayingClip = null;
-        }
-
-        if (ReferenceEquals(SelectedClip, clip))
-        {
-            SelectedClip = null;
-        }
-
-        OnPropertyChanged(nameof(FilteredClips));
-        OnPropertyChanged(nameof(ClipCount));
-        RefreshClipState();
+        // Never block the caller: a synchronous hop from a background thread while the UI thread waits on that thread is a deadlock.
+        _dispatcher.BeginInvoke(action);
     }
 
-    [RelayCommand(CanExecute = nameof(CanShowOnMap))]
-    private void ShowOnMap(CamClip clip)
+    private void OnLibraryPropertyChanged(object sender, PropertyChangedEventArgs e)
     {
-        if (clip?.Event is null || !ClipDisplay.HasLocation(clip.Event))
+        switch (e.PropertyName)
         {
-            return;
-        }
-
-        var lat = clip.Event.EstLat.ToString(CultureInfo.InvariantCulture);
-        var lon = clip.Event.EstLon.ToString(CultureInfo.InvariantCulture);
-        Process.Start(new ProcessStartInfo($"https://www.google.com/maps?q={lat},{lon}") { UseShellExecute = true });
-    }
-
-    private static bool CanShowOnMap(CamClip clip) => clip?.Event is not null && ClipDisplay.HasLocation(clip.Event);
+            case nameof(ClipLibraryViewModel.SelectedClip):
+                OnSelectedClipChanged(Library.SelectedClip);
+                OnPropertyChanged(nameof(HasNoClipSelected));
+                OnPropertyChanged(nameof(ShowStatusOverlay));
+                OnPropertyChanged(nameof(ShowVideoHosts));
+                break;
 
-    private void InvokeOnDispatcher(Action action)
-    {
-        if (_dispatcher.CheckAccess())
-        {
-            action();
-            return;
+            case nameof(ClipLibraryViewModel.IsLoadingClips):
+                OnPropertyChanged(nameof(IsLoading));
+                OnPropertyChanged(nameof(ShowStatusOverlay));
+                OnPropertyChanged(nameof(ShowVideoHosts));
+                OnPropertyChanged(nameof(HasNoClipSelected));
+                break;
         }
-
-        // Never block the caller: a synchronous hop from a background thread while the UI thread waits on that thread is a deadlock.
-        _dispatcher.BeginInvoke(action);
     }
 
-    partial void OnSelectedClipChanged(CamClip value)
+    private void OnSelectedClipChanged(CamClip value)
     {
         Cameras.ShowCamerasOf(value);
 
diff --git a/SentryDeck/ViewModels/ClipLibraryViewModel.cs b/SentryDeck/ViewModels/ClipLibraryViewModel.cs
new file mode 100644
index 0000000..325e19d
--- /dev/null
+++ b/SentryDeck/ViewModels/ClipLibraryViewModel.cs
@@ -0,0 +1,403 @@
+using System.Diagnostics;
+using System.Globalization;
+using System.IO;
+using System.Windows;
+using System.Windows.Threading;
+using CommunityToolkit.Mvvm.ComponentModel;
+using CommunityToolkit.Mvvm.Input;
+using Microsoft.VisualBasic.FileIO;
+using Microsoft.Win32;
+using Serilog;
+
+namespace SentryDeck;
+
+/// <summary>
+/// The clip list: scanning dashcam folders, searching, the selected clip, and the per-clip actions in its context menu.
+/// </summary>
+public sealed partial class ClipLibraryViewModel : ObservableObject
+{
+    private readonly List<CamClip> _allClips = [];
+    private readonly Func<string, IReadOnlyList<CamClip>> _clipLoader;
+    private readonly PlaybackViewModel _playback;
+    private readonly ErrorOverlayViewModel _error;
+    private readonly DispatcherTimer _filterDebounceTimer;
+
+    // The source of dashcam roots: auto-discovery by default, or the user's last picked folders.
+    // Refresh re-evaluates it to rescan for newly added clips (and, for auto-discovery, newly connected drives).
+    private Func<IEnumerable<string>> _rootSource = CamStorage.FindCommonRoots;
+
+    /// <param name="clipLoader">Maps a dashcam root to its clips.</param>
+    /// <param name="playback">The player, which is stopped before a rescan or a delete and follows the clip list's playlist.</param>
+    /// <param name="error">Where scan and delete failures are reported.</param>
+    /// <param name="dispatcher">Runs the search debounce.</param>
+    public ClipLibraryViewModel(
+        Func<string, IReadOnlyList<CamClip>> clipLoader,
+        PlaybackViewModel playback,
+        ErrorOverlayViewModel error,
+        Dispatcher dispatcher)
+    {
+        _clipLoader = clipLoader;
+        _playback = playback;
+        _error = error;
+
+        // Coalesces the expensive clip-list regroup/rebind so fast typing in search stays smooth; the getters stay live, so only the (debounced) change notification is deferred.
+        _filterDebounceTimer = new DispatcherTimer(DispatcherPriority.Background, dispatcher)
+        {
+            Interval = TimeSpan.FromMilliseconds(150),
+        };
+        _filterDebounceTimer.Tick += OnFilterDebounceTick;
+    }
+
+    public IReadOnlyList<CamClip> FilteredClips => _allClips
+        .Where(MatchesFilter)
+        .OrderByDescending(c => c.Timestamp)
+        .ThenBy(c => c.Name)
+        .ToList();
+
+    /// <summary>Number of clips currently shown (drives the sidebar count).</summary>
+    public int ClipCount => FilteredClips.Count;
+
+    /// <summary>True when the search box has text (drives the clear button).</summary>
+    public bool HasFilterText => !string.IsNullOrEmpty(FilterText);
+
+    // FilteredClips/ClipCount are refreshed on a short debounce (see OnFilterTextChanged) rather than per keystroke; HasFilterText stays immediate so the search box's clear affordance is responsive.
+    [ObservableProperty]
+    [NotifyPropertyChangedFor(nameof(HasFilterText))]
+    private string _filterText = string.Empty;
+
+    [ObservableProperty]
+    private CamClip _selectedClip;
+
+    // True while the clip list is being (re)scanned from disk; drives the sidebar loading indicator.
+    [ObservableProperty]
+    [NotifyCanExecuteChangedFor(nameof(RefreshClipsCommand))]
+    [NotifyCanExecuteChangedFor(nameof(OpenFolderCommand))]
+    private bool _isLoadingClips;
+
+    /// <summary>
+    /// Asks the user to confirm sending a clip to the Recycle Bin.
+    /// Returns true to proceed.
+    /// Overridable for tests; defaults to a yes/no message box.
+    /// </summary>
+    internal Func<CamClip, bool> ConfirmDeleteClip { get; set; } = clip =>
+        MessageBox.Show(
+            $"Move this clip to the Recycle Bin?\n\n{clip.Name}\n{clip.FullPath}",
+            "Delete clip",
+            MessageBoxButton.YesNo,
+            MessageBoxImage.Warning) == MessageBoxResult.Yes;
+
+    /// <summary>
+    /// Sends a clip folder to the Windows Recycle Bin (recoverable).
+    /// Overridable for tests; defaults to the shell recycle operation, which surfaces its own error dialog if a file is in use.
+    /// </summary>
+    internal Action<string> RecycleClipFolder { get; set; } = path =>
+        FileSystem.DeleteDirectory(path, UIOption.OnlyErrorDialogs, RecycleOption.SendToRecycleBin);
+
+    /// <summary>Rescans the current source of dashcam roots (auto-discovered drives, or the folders the user picked).</summary>
+    public Task ReloadAsync(TimeSpan minimumLoadingDuration = default) => LoadClipsAsync(_rootSource(), minimumLoadingDuration);
+
+    public async Task LoadClipsAsync(IEnumerable<string> roots, TimeSpan minimumLoadingDuration = default)
+    {
+        _error.Clear();
+        _allClips.Clear();
+        SelectedClip = null;
+        IsLoadingClips = true;
+
+        // Clear the list right away so a (re)scan visibly empties it and shows the loading bar before refilling.
+        OnPropertyChanged(nameof(FilteredClips));
+        OnPropertyChanged(nameof(ClipCount));
+
+        var stopwatch = Stopwatch.StartNew();
+
+        try
+        {
+            // Scan the disk off the UI thread; the continuation resumes on it via the WPF SynchronizationContext, so all view-model state below is mutated on the UI thread.
+            var result = await Task.Run(() => ScanRoots(roots));
+
+            if (!result.HadRoots)
+            {
+                _error.Show(
+                    "No dashcam footage yet",
+                    "Point Sentry Deck at your TeslaCam folder to get started. Recorded USB drives are found automatically.",
+                    canDismiss: true,
+                    isEmptyState: true);
+            }
+            else
+            {
+                _allClips.AddRange(result.Clips);
+                foreach (var error in result.Errors)
+                {
+                    _error.Show(error.Title, error.Details);
+                }
+            }
+
+            _playback.SetPlaylist(_allClips);
+
+            // Hold the loading state briefly so a fast rescan still reads as a deliberate refresh (clear -> loading -> refill) instead of an imperceptible flicker.
+            var remaining = minimumLoadingDuration - stopwatch.Elapsed;
+            if (remaining > TimeSpan.Zero)
+            {
+                await Task.Delay(remaining);
+            }
+        }
+        finally
+        {
+            IsLoadingClips = false;
+            OnPropertyChanged(nameof(FilteredClips));
+            OnPropertyChanged(nameof(ClipCount));
+        }
+    }
+
+    public void Shutdown() => _filterDebounceTimer.Stop();
+
+    // Matches the clip name, path, event city, and friendly event reason (e.g. "sentry", "honk", "saved").
+    private bool MatchesFilter(CamClip clip)
+    {
+        if (string.IsNullOrWhiteSpace(FilterText))
+        {
+            return true;
+        }
+
+        var term = FilterText;
+        return clip.Name.Contains(term, StringComparison.CurrentCultureIgnoreCase)
+            || clip.FullPath.Contains(term, StringComparison.CurrentCultureIgnoreCase)
+            || (clip.Event?.City?.Contains(term, StringComparison.CurrentCultureIgnoreCase) ?? false)
+            || ClipDisplay.ReasonLabel(clip.Event).Contains(term, StringComparison.CurrentCultureIgnoreCase);
+    }
+
+    // Restart the debounce on each keystroke; the list is rebound once typing settles.
+    partial void OnFilterTextChanged(string value)
+    {
+        _filterDebounceTimer.Stop();
+        _filterDebounceTimer.Start();
+    }
+
+    private void OnFilterDebounceTick(object sender, EventArgs e)
+    {
+        _filterDebounceTimer.Stop();
+        OnPropertyChanged(nameof(FilteredClips));
+        OnPropertyChanged(nameof(ClipCount));
+    }
+
+    private ScanResult ScanRoots(IEnumerable<string> roots)
+    {
+        var rootList = roots?.Where(root => !string.IsNullOrWhiteSpace(root)).ToList() ?? [];
+        if (rootList.Count == 0)
+        {
+            Log.Information("No dashcam roots found");
+            return new ScanResult([], [], HadRoots: false);
+        }
+
+        Log.Information("Loading dashcam clips. RootCount={RootCount}; Roots={Roots}", rootList.Count, rootList);
+        var totalStopwatch = Stopwatch.StartNew();
+        var clips = new List<CamClip>();
+        var errors = new List<ClipLoadError>();
+
+        foreach (var root in rootList)
+        {
+            var rootStopwatch = Stopwatch.StartNew();
+            Log.Debug("Scanning dashcam root. Root={Root}", root);
+
+            try
+            {
+                var rootClips = _clipLoader(root);
+                clips.AddRange(rootClips);
+                Log.Information(
+                    "Scanned dashcam root. Root={Root}; ClipCount={ClipCount}; ElapsedMs={ElapsedMs}",
+                    root,
+                    rootClips.Count,
+                    rootStopwatch.ElapsedMilliseconds);
+            }
+            catch (UnauthorizedAccessException ex)
+            {
+                Log.Error(ex, "Access denied while loading dashcam root. Root={Root}", root);
+                errors.Add(new ClipLoadError("Access Denied", $"Cannot access folder: {root}\n\nCheck that you have permission to read this location."));
+            }
+            catch (Exception ex)
+            {
+                Log.Error(ex, "Failed to load dashcam root. Root={Root}", root);
+                errors.Add(new ClipLoadError("Error Loading Clips", $"Failed to load clips from:\n{root}\n\nError: {ex.Message}"));
+            }
+        }
+
+        Log.Information(
+            "Finished loading dashcam clips. ClipCount={ClipCount}; RootCount={RootCount}; FailedRootCount={FailedRootCount}; ElapsedMs={ElapsedMs}",
+            clips.Count,
+            rootList.Count,
+            errors.Count,
+            totalStopwatch.ElapsedMilliseconds);
+        return new ScanResult(clips, errors, HadRoots: true);
+    }
+
+    private sealed record ScanResult(IReadOnlyList<CamClip> Clips, IReadOnlyList<ClipLoadError> Errors, bool HadRoots);
+
+    private sealed record ClipLoadError(string Title, string Details);
+
+    // Gated like Refresh: LoadClipsAsync has no re-entrancy protection, so picking a folder while a scan is still running would interleave two loads and merge both roots into one clip list.
+    [RelayCommand(CanExecute = nameof(CanRefreshClips))]
+    private async Task OpenFolderAsync()
+    {
+        Log.Debug("Opening folder picker");
+
+        var dialog = new OpenFolderDialog
+        {
+            Multiselect = true,
+            Title = "Select a folder containing Tesla dashcam footage (TeslaCam folder)",
+        };
+
+        if (dialog.ShowDialog() == true)
+        {
+            var folders = dialog.FolderNames;
+            Log.Information(
+                "User selected dashcam folders. FolderCount={FolderCount}; Folders={Folders}",
+                folders.Length,
+                folders);
+
+            await _playback.StopPlayerAsync();
+
+            _rootSource = () => folders;
+            await LoadClipsAsync(folders);
+        }
+        else
+        {
+            Log.Debug("Folder picker canceled");
+        }
+    }
+
+    [RelayCommand(CanExecute = nameof(CanRefreshClips))]
+    private async Task RefreshClipsAsync()
+    {
+        Log.Debug("Refreshing clips");
+
+        await _playback.StopPlayerAsync();
+        await ReloadAsync(TimeSpan.FromMilliseconds(400));
+    }
+
+    private bool CanRefreshClips => !IsLoadingClips;
+
+    [RelayCommand]
+    private void ClearFilter()
+    {
+        FilterText = string.Empty;
+    }
+
+    private static bool CanUseClip(CamClip clip)
+    {
+        return clip is not null;
+    }
+
+    [RelayCommand(CanExecute = nameof(CanUseClip))]
+    private void OpenClipFolder(CamClip clip)
+    {
+        if (clip is null)
+        {
+            return;
+        }
+
+        if (!Directory.Exists(clip.FullPath))
+        {
+            _error.Show("Clip Folder Not Found", $"Could not find folder:\n{clip.FullPath}");
+            return;
+        }
+
+        Process.Start(new ProcessStartInfo(clip.FullPath)
+        {
+            UseShellExecute = true,
+        });
+    }
+
+    [RelayCommand(CanExecute = nameof(CanUseClip))]
+    private void CopyClipPath(CamClip clip)
+    {
+        if (clip is not null)
+        {
+            Clipboard.SetText(clip.FullPath);
+        }
+    }
+
+    [RelayCommand(CanExecute = nameof(CanUseClip))]
+    private void CopyClipName(CamClip clip)
+    {
+        if (clip is not null)
+        {
+            Clipboard.SetText(clip.Name);
+        }
+    }
+
+    [RelayCommand(CanExecute = nameof(CanUseClip))]
+    private void CopyTimestamp(CamClip clip)
+    {
+        if (clip is not null)
+        {
+            // Invariant (24-hour, culture-stable) so the copied value matches the clip name and is paste-searchable, unlike the ambiguous AM/PM current-culture rendering.
+            Clipboard.SetText(clip.Timestamp.ToString(CultureInfo.InvariantCulture));
+        }
+    }
+
+    /// <summary>
+    /// Sends the clip's folder to the Recycle Bin so the timeline can be tidied without leaving the app.
+    /// Confirms first, then, if the clip is the one currently open, stops playback so Flyleaf releases its file handles before the shell tries to recycle the (otherwise locked) folder.
+    /// </summary>
+    [RelayCommand(CanExecute = nameof(CanUseClip))]
+    private async Task DeleteClipAsync(CamClip clip)
+    {
+        if (clip is null || !ConfirmDeleteClip(clip))
+        {
+            return;
+        }
+
+        // Flyleaf keeps the current clip's camera files open; Windows can't recycle a folder whose files are still locked, so stop and close the players before deleting it.
+        var isCurrent = ReferenceEquals(SelectedClip, clip)
+            || ReferenceEquals(_playback.NowPlayingClip, clip)
+            || _playback.CurrentClip == clip;
+        if (isCurrent && _playback.HasPlayer)
+        {
+            await _playback.StopPlayerAsync();
+            _playback.SeekPosition = 0;
+        }
+
+        try
+        {
+            Log.Information("Deleting clip to Recycle Bin. ClipName={ClipName}; ClipPath={ClipPath}", clip.Name, clip.FullPath);
+            await Task.Run(() => RecycleClipFolder(clip.FullPath));
+        }
+        catch (Exception ex)
+        {
+            Log.Error(ex, "Failed to delete clip. ClipName={ClipName}; ClipPath={ClipPath}", clip.Name, clip.FullPath);
+            _error.Show("Delete Failed", $"Could not delete clip: {clip.Name}\n\nError: {ex.Message}");
+            return;
+        }
+
+        // Drop it from the sidebar list and keep the player's Next/Previous playlist in sync.
+        _allClips.Remove(clip);
+        _playback.RemoveFromPlaylist(clip);
+
+        if (ReferenceEquals(_playback.NowPlayingClip, clip))
+        {
+            _playback.NowPlayingClip = null;
+        }
+
+        if (ReferenceEquals(SelectedClip, clip))
+        {
+            SelectedClip = null;
+        }
+
+        OnPropertyChanged(nameof(FilteredClips));
+        OnPropertyChanged(nameof(ClipCount));
+    }
+
+    [RelayCommand(CanExecute = nameof(CanShowOnMap))]
+    private void ShowOnMap(CamClip clip)
+    {
+        if (clip?.Event is null || !ClipDisplay.HasLocation(clip.Event))
+        {
+            return;
+        }
+
+        var lat = clip.Event.EstLat.ToString(CultureInfo.InvariantCulture);
+        var lon = clip.Event.EstLon.ToString(CultureInfo.InvariantCulture);
+        Process.Start(new ProcessStartInfo($"https://www.google.com/maps?q={lat},{lon}") { UseShellExecute = true });
+    }
+
+    private static bool CanShowOnMap(CamClip clip) => clip?.Event is not null && ClipDisplay.HasLocation(clip.Event);
+}

From 2ea9f0f8333828465c5a225b2b07867e135bf05d Mon Sep 17 00:00:00 2001
From: Daniel Chalmers <daniel.chalmers@outlook.com>
Date: Thu, 24 Sep 2026 07:49:10 -0500
Subject: [PATCH 7/8] Move trim and export into their own view-model

TrimViewModel owns the trim panel's in/out marks and both exports (the marked range and "Save event clip"). It follows the player on its own: its commands re-check whenever seeking becomes possible or impossible, and the marks are dropped when the player rebuilds the clip's media, since they no longer point at the same footage.

This finishes the split. MainWindowViewModel is down from about 1,900 lines to about 430 and now only composes the feature view-models and owns what spans them: startup, the overlay over the video area, the About page toggle, the FFmpeg prompt, and keyboard shortcuts.
---
 .../MainWindowViewModelTests.Trimming.cs      | 150 ++---
 SentryDeck.Tests/MainWindowViewModelTests.cs  |   4 +-
 SentryDeck/MainWindow.xaml                    |  32 +-
 SentryDeck/MainWindowViewModel.cs             | 518 ++++--------------
 SentryDeck/ViewModels/TrimViewModel.cs        | 372 +++++++++++++
 5 files changed, 563 insertions(+), 513 deletions(-)
 create mode 100644 SentryDeck/ViewModels/TrimViewModel.cs

diff --git a/SentryDeck.Tests/MainWindowViewModelTests.Trimming.cs b/SentryDeck.Tests/MainWindowViewModelTests.Trimming.cs
index 581cfb2..a6c3443 100644
--- a/SentryDeck.Tests/MainWindowViewModelTests.Trimming.cs
+++ b/SentryDeck.Tests/MainWindowViewModelTests.Trimming.cs
@@ -16,18 +16,18 @@ public void MarkSelection_SetsFractions_AndCompletesTheRange()
         controller.IsMediaOpen = true;
 
         vm.Playback.SeekPosition = 0.3;
-        vm.MarkSelectionStartCommand.Execute(null);
+        vm.Trim.MarkSelectionStartCommand.Execute(null);
 
-        vm.HasSelectionStart.ShouldBeTrue();
-        vm.SelectionStartPosition.ShouldBe(0.3);
-        vm.HasSelection.ShouldBeFalse(); // no end yet
+        vm.Trim.HasSelectionStart.ShouldBeTrue();
+        vm.Trim.SelectionStartPosition.ShouldBe(0.3);
+        vm.Trim.HasSelection.ShouldBeFalse(); // no end yet
 
         vm.Playback.SeekPosition = 0.7;
-        vm.MarkSelectionEndCommand.Execute(null);
+        vm.Trim.MarkSelectionEndCommand.Execute(null);
 
-        vm.HasSelection.ShouldBeTrue();
-        vm.SelectionEndPosition.ShouldBe(0.7);
-        vm.CanExportSelection.ShouldBeTrue();
+        vm.Trim.HasSelection.ShouldBeTrue();
+        vm.Trim.SelectionEndPosition.ShouldBe(0.7);
+        vm.Trim.CanExportSelection.ShouldBeTrue();
     }
 
     [Fact]
@@ -38,21 +38,21 @@ public void MarkSelection_InvertedOrder_ClearsTheOtherMark()
         controller.IsMediaOpen = true;
 
         vm.Playback.SeekPosition = 0.3;
-        vm.MarkSelectionStartCommand.Execute(null);
+        vm.Trim.MarkSelectionStartCommand.Execute(null);
         vm.Playback.SeekPosition = 0.7;
-        vm.MarkSelectionEndCommand.Execute(null);
+        vm.Trim.MarkSelectionEndCommand.Execute(null);
 
         // A start at/past the end invalidates the end...
         vm.Playback.SeekPosition = 0.9;
-        vm.MarkSelectionStartCommand.Execute(null);
-        vm.SelectionStartPosition.ShouldBe(0.9);
-        vm.HasSelectionEnd.ShouldBeFalse();
+        vm.Trim.MarkSelectionStartCommand.Execute(null);
+        vm.Trim.SelectionStartPosition.ShouldBe(0.9);
+        vm.Trim.HasSelectionEnd.ShouldBeFalse();
 
         // ...and an end at/before the start invalidates the start.
         vm.Playback.SeekPosition = 0.1;
-        vm.MarkSelectionEndCommand.Execute(null);
-        vm.SelectionEndPosition.ShouldBe(0.1);
-        vm.HasSelectionStart.ShouldBeFalse();
+        vm.Trim.MarkSelectionEndCommand.Execute(null);
+        vm.Trim.SelectionEndPosition.ShouldBe(0.1);
+        vm.Trim.HasSelectionStart.ShouldBeFalse();
     }
 
     [Fact]
@@ -62,16 +62,16 @@ public void ClearSelection_RemovesBothMarks()
         controller.Duration = TimeSpan.FromMinutes(1);
         controller.IsMediaOpen = true;
 
-        vm.ClearSelectionCommand.CanExecute(null).ShouldBeFalse(); // nothing to clear yet
+        vm.Trim.ClearSelectionCommand.CanExecute(null).ShouldBeFalse(); // nothing to clear yet
 
         vm.Playback.SeekPosition = 0.2;
-        vm.MarkSelectionStartCommand.Execute(null);
-        vm.HasAnySelectionMark.ShouldBeTrue();
+        vm.Trim.MarkSelectionStartCommand.Execute(null);
+        vm.Trim.HasAnySelectionMark.ShouldBeTrue();
 
-        vm.ClearSelectionCommand.Execute(null);
+        vm.Trim.ClearSelectionCommand.Execute(null);
 
-        vm.HasAnySelectionMark.ShouldBeFalse();
-        vm.HasSelection.ShouldBeFalse();
+        vm.Trim.HasAnySelectionMark.ShouldBeFalse();
+        vm.Trim.HasSelection.ShouldBeFalse();
     }
 
     [Fact]
@@ -82,11 +82,11 @@ public void Selection_ClearsWhenAnotherClipIsSelected()
         controller.IsMediaOpen = true;
 
         vm.Playback.SeekPosition = 0.2;
-        vm.MarkSelectionStartCommand.Execute(null);
+        vm.Trim.MarkSelectionStartCommand.Execute(null);
 
         vm.Library.SelectedClip = TestClips.Create(1)[0];
 
-        vm.HasAnySelectionMark.ShouldBeFalse();
+        vm.Trim.HasAnySelectionMark.ShouldBeFalse();
     }
 
     [Fact]
@@ -100,15 +100,15 @@ public void TrimCommands_ReEnableWhenLoadingEndsLast()
         controller.IsMediaOpen = true;
 
         var trimCanExecuteChanged = false;
-        vm.ToggleTrimmingCommand.CanExecuteChanged += (_, _) => trimCanExecuteChanged = true;
+        vm.Trim.ToggleTrimmingCommand.CanExecuteChanged += (_, _) => trimCanExecuteChanged = true;
 
         vm.Playback.IsLoading = false;
 
         vm.Playback.CanSeek.ShouldBeTrue();
         trimCanExecuteChanged.ShouldBeTrue();
-        vm.ToggleTrimmingCommand.CanExecute(null).ShouldBeTrue();
-        vm.MarkSelectionStartCommand.CanExecute(null).ShouldBeTrue();
-        vm.MarkSelectionEndCommand.CanExecute(null).ShouldBeTrue();
+        vm.Trim.ToggleTrimmingCommand.CanExecute(null).ShouldBeTrue();
+        vm.Trim.MarkSelectionStartCommand.CanExecute(null).ShouldBeTrue();
+        vm.Trim.MarkSelectionEndCommand.CanExecute(null).ShouldBeTrue();
     }
 
     [Fact]
@@ -118,12 +118,12 @@ public void MarkingAPoint_OpensTheTrimPanel()
         controller.Duration = TimeSpan.FromMinutes(1);
         controller.IsMediaOpen = true;
 
-        vm.IsTrimming.ShouldBeFalse();
+        vm.Trim.IsTrimming.ShouldBeFalse();
 
         vm.Playback.SeekPosition = 0.3;
-        vm.MarkSelectionStartCommand.Execute(null);
+        vm.Trim.MarkSelectionStartCommand.Execute(null);
 
-        vm.IsTrimming.ShouldBeTrue();
+        vm.Trim.IsTrimming.ShouldBeTrue();
     }
 
     [Fact]
@@ -133,17 +133,17 @@ public void ToggleTrimming_OpensEmpty_AndClosingDiscardsTheMarks()
         controller.Duration = TimeSpan.FromMinutes(1);
         controller.IsMediaOpen = true;
 
-        vm.ToggleTrimmingCommand.Execute(null);
-        vm.IsTrimming.ShouldBeTrue();
-        vm.HasAnySelectionMark.ShouldBeFalse();
+        vm.Trim.ToggleTrimmingCommand.Execute(null);
+        vm.Trim.IsTrimming.ShouldBeTrue();
+        vm.Trim.HasAnySelectionMark.ShouldBeFalse();
 
         vm.Playback.SeekPosition = 0.3;
-        vm.MarkSelectionStartCommand.Execute(null);
+        vm.Trim.MarkSelectionStartCommand.Execute(null);
 
-        vm.ToggleTrimmingCommand.Execute(null); // acts as cancel while open
+        vm.Trim.ToggleTrimmingCommand.Execute(null); // acts as cancel while open
 
-        vm.IsTrimming.ShouldBeFalse();
-        vm.HasAnySelectionMark.ShouldBeFalse();
+        vm.Trim.IsTrimming.ShouldBeFalse();
+        vm.Trim.HasAnySelectionMark.ShouldBeFalse();
     }
 
     [Fact]
@@ -154,14 +154,14 @@ public void CancelTrim_ClosesThePanelAndDiscardsTheMarks()
         controller.IsMediaOpen = true;
 
         vm.Playback.SeekPosition = 0.3;
-        vm.MarkSelectionStartCommand.Execute(null);
+        vm.Trim.MarkSelectionStartCommand.Execute(null);
         vm.Playback.SeekPosition = 0.7;
-        vm.MarkSelectionEndCommand.Execute(null);
+        vm.Trim.MarkSelectionEndCommand.Execute(null);
 
-        vm.CancelTrimCommand.Execute(null);
+        vm.Trim.CancelTrimCommand.Execute(null);
 
-        vm.IsTrimming.ShouldBeFalse();
-        vm.HasAnySelectionMark.ShouldBeFalse();
+        vm.Trim.IsTrimming.ShouldBeFalse();
+        vm.Trim.HasAnySelectionMark.ShouldBeFalse();
     }
 
     [Fact]
@@ -171,10 +171,10 @@ public void TrimPanel_ClosesWhenAnotherClipIsSelected()
         controller.Duration = TimeSpan.FromMinutes(1);
         controller.IsMediaOpen = true;
 
-        vm.ToggleTrimmingCommand.Execute(null);
+        vm.Trim.ToggleTrimmingCommand.Execute(null);
         vm.Library.SelectedClip = TestClips.Create(1)[0];
 
-        vm.IsTrimming.ShouldBeFalse();
+        vm.Trim.IsTrimming.ShouldBeFalse();
     }
 
     [Fact]
@@ -184,18 +184,18 @@ public void TrimHintText_WalksThroughStartEndExport()
         controller.Duration = TimeSpan.FromMinutes(2);
         controller.IsMediaOpen = true;
 
-        vm.TrimHintText.ShouldContain("set the start");
+        vm.Trim.TrimHintText.ShouldContain("set the start");
 
         vm.Playback.SeekPosition = 0.25;
-        vm.MarkSelectionStartCommand.Execute(null);
-        vm.TrimHintText.ShouldContain("set the end");
+        vm.Trim.MarkSelectionStartCommand.Execute(null);
+        vm.Trim.TrimHintText.ShouldContain("set the end");
 
         vm.Playback.SeekPosition = 0.75;
-        vm.MarkSelectionEndCommand.Execute(null);
+        vm.Trim.MarkSelectionEndCommand.Execute(null);
 
         // Half of a 2:00 clip is selected.
-        vm.SelectionDurationText.ShouldBe("1:00");
-        vm.TrimHintText.ShouldBe("1:00 selected — ready to export.");
+        vm.Trim.SelectionDurationText.ShouldBe("1:00");
+        vm.Trim.TrimHintText.ShouldBe("1:00 selected — ready to export.");
     }
 
     [Fact]
@@ -203,9 +203,9 @@ public void MarkSelection_RequiresSeekableMedia()
     {
         var vm = CreateViewModel();
 
-        vm.MarkSelectionStartCommand.CanExecute(null).ShouldBeFalse();
-        vm.MarkSelectionEndCommand.CanExecute(null).ShouldBeFalse();
-        vm.ExportSelectionCommand.CanExecute(null).ShouldBeFalse();
+        vm.Trim.MarkSelectionStartCommand.CanExecute(null).ShouldBeFalse();
+        vm.Trim.MarkSelectionEndCommand.CanExecute(null).ShouldBeFalse();
+        vm.Trim.ExportSelectionCommand.CanExecute(null).ShouldBeFalse();
     }
 
     // Synchronous/blocking for the same thread-affinity reason as the drag-sequence test above (see RunPinnedToTestThread): the fake exporter and save picker complete synchronously.
@@ -218,11 +218,11 @@ public void ExportSelection_SendsMediaTimeRangeAndActiveCameraToTheExporter()
 
         vm.Cameras.SelectCameraViewCommand.Execute(CameraNames.Back);
         vm.Playback.SeekPosition = 0.25;
-        vm.MarkSelectionStartCommand.Execute(null);
+        vm.Trim.MarkSelectionStartCommand.Execute(null);
         vm.Playback.SeekPosition = 0.75;
-        vm.MarkSelectionEndCommand.Execute(null);
+        vm.Trim.MarkSelectionEndCommand.Execute(null);
 
-        RunPinnedToTestThread(() => vm.ExportSelectionCommand.ExecuteAsync(null));
+        RunPinnedToTestThread(() => vm.Trim.ExportSelectionCommand.ExecuteAsync(null));
 
         var request = exporter.Requests.ShouldHaveSingleItem();
         request.Clip.ShouldBe(clipFiles.Clip);
@@ -230,7 +230,7 @@ public void ExportSelection_SendsMediaTimeRangeAndActiveCameraToTheExporter()
         request.Start.ShouldBe(TimeSpan.FromSeconds(15));
         request.End.ShouldBe(TimeSpan.FromSeconds(45));
         request.OutputPath.ShouldBe(@"C:\out\clip.mp4");
-        vm.IsExporting.ShouldBeFalse();
+        vm.Trim.IsExporting.ShouldBeFalse();
     }
 
     [Fact]
@@ -241,11 +241,11 @@ public void ExportSelection_SaveDialogCanceled_DoesNotExport()
         var (vm, _, _) = CreateViewModelWithOpenedClip(clipFiles.Clip, exporter, _ => null);
 
         vm.Playback.SeekPosition = 0.25;
-        vm.MarkSelectionStartCommand.Execute(null);
+        vm.Trim.MarkSelectionStartCommand.Execute(null);
         vm.Playback.SeekPosition = 0.75;
-        vm.MarkSelectionEndCommand.Execute(null);
+        vm.Trim.MarkSelectionEndCommand.Execute(null);
 
-        RunPinnedToTestThread(() => vm.ExportSelectionCommand.ExecuteAsync(null));
+        RunPinnedToTestThread(() => vm.Trim.ExportSelectionCommand.ExecuteAsync(null));
 
         exporter.Requests.ShouldBeEmpty();
         vm.Error.IsVisible.ShouldBeFalse();
@@ -259,16 +259,16 @@ public void ExportSelection_ExporterFailure_ShowsErrorAndResetsBusyState()
         var (vm, _, _) = CreateViewModelWithOpenedClip(clipFiles.Clip, exporter, _ => @"C:\out\clip.mp4");
 
         vm.Playback.SeekPosition = 0.25;
-        vm.MarkSelectionStartCommand.Execute(null);
+        vm.Trim.MarkSelectionStartCommand.Execute(null);
         vm.Playback.SeekPosition = 0.75;
-        vm.MarkSelectionEndCommand.Execute(null);
+        vm.Trim.MarkSelectionEndCommand.Execute(null);
 
-        RunPinnedToTestThread(() => vm.ExportSelectionCommand.ExecuteAsync(null));
+        RunPinnedToTestThread(() => vm.Trim.ExportSelectionCommand.ExecuteAsync(null));
 
         vm.Error.IsVisible.ShouldBeTrue();
         vm.Error.Title.ShouldBe("Export Failed");
         vm.Error.Details.ShouldContain("ffmpeg exploded");
-        vm.IsExporting.ShouldBeFalse();
+        vm.Trim.IsExporting.ShouldBeFalse();
     }
 
     [Fact]
@@ -284,10 +284,10 @@ public async Task SaveEventClip_ExportsFrontCameraWindowAroundTheEvent()
             savePathPicker: _ => @"C:\out\event.mp4",
             exportMediaSourceBuilder: new FakeClipMediaSourceBuilder())
         {
-            RevealInExplorer = _ => { },
+            Trim = { RevealInExplorer = _ => { } },
         };
 
-        await vm.SaveEventClipCommand.ExecuteAsync(clip);
+        await vm.Trim.SaveEventClipCommand.ExecuteAsync(clip);
 
         var request = exporter.Requests.ShouldHaveSingleItem();
         request.Camera.ShouldBe(CameraNames.Front);
@@ -308,10 +308,10 @@ public async Task SaveEventClip_WindowIsClampedToTheClip()
             savePathPicker: _ => @"C:\out\event.mp4",
             exportMediaSourceBuilder: new FakeClipMediaSourceBuilder())
         {
-            RevealInExplorer = _ => { },
+            Trim = { RevealInExplorer = _ => { } },
         };
 
-        await vm.SaveEventClipCommand.ExecuteAsync(clip);
+        await vm.Trim.SaveEventClipCommand.ExecuteAsync(clip);
 
         var request = exporter.Requests.ShouldHaveSingleItem();
         request.Start.ShouldBe(TimeSpan.Zero);
@@ -331,15 +331,15 @@ public async Task SaveEventClip_BuilderThrows_ShowsErrorInsteadOfCrashing()
             savePathPicker: _ => @"C:\out\event.mp4",
             exportMediaSourceBuilder: new ThrowingClipMediaSourceBuilder(new IOException("drive gone")))
         {
-            RevealInExplorer = _ => { },
+            Trim = { RevealInExplorer = _ => { } },
         };
 
-        await vm.SaveEventClipCommand.ExecuteAsync(clip);
+        await vm.Trim.SaveEventClipCommand.ExecuteAsync(clip);
 
         vm.Error.IsVisible.ShouldBeTrue();
         vm.Error.Title.ShouldBe("Export Failed");
         exporter.Requests.ShouldBeEmpty();
-        vm.IsExporting.ShouldBeFalse();
+        vm.Trim.IsExporting.ShouldBeFalse();
     }
 
     private sealed class ThrowingClipMediaSourceBuilder(Exception exception) : IClipMediaSourceBuilder
@@ -352,9 +352,9 @@ public void SaveEventClip_RequiresAnEventMoment()
     {
         var vm = CreateViewModel();
 
-        vm.SaveEventClipCommand.CanExecute(ClipWithChunks(1)).ShouldBeFalse(); // no event
-        vm.SaveEventClipCommand.CanExecute(ClipWithEvent("clip", "sentry_aware_object_detection", "Bellevue")).ShouldBeFalse(); // event without timestamp
-        vm.SaveEventClipCommand.CanExecute(ClipWithChunksAndEvent(1, TimeSpan.FromSeconds(10))).ShouldBeTrue();
+        vm.Trim.SaveEventClipCommand.CanExecute(ClipWithChunks(1)).ShouldBeFalse(); // no event
+        vm.Trim.SaveEventClipCommand.CanExecute(ClipWithEvent("clip", "sentry_aware_object_detection", "Bellevue")).ShouldBeFalse(); // event without timestamp
+        vm.Trim.SaveEventClipCommand.CanExecute(ClipWithChunksAndEvent(1, TimeSpan.FromSeconds(10))).ShouldBeTrue();
     }
 
     [Fact]
diff --git a/SentryDeck.Tests/MainWindowViewModelTests.cs b/SentryDeck.Tests/MainWindowViewModelTests.cs
index 2d3ba1a..5bdca20 100644
--- a/SentryDeck.Tests/MainWindowViewModelTests.cs
+++ b/SentryDeck.Tests/MainWindowViewModelTests.cs
@@ -131,7 +131,7 @@ private VideoPlayerController BuildFourCameraController(FakeCameraPlayer front)
             savePathPicker: savePathPicker,
             uiInvoker: uiInvoker)
         {
-            RevealInExplorer = _ => { },
+            Trim = { RevealInExplorer = _ => { } },
         };
         vm.InitializePlayer();
         return (vm, built, front);
@@ -520,7 +520,7 @@ public async Task AboutPage_SwallowsPlayerShortcuts(Key key, ModifierKeys modifi
 
         handled.ShouldBeFalse();
         vm.Cameras.SelectedCameraView.ShouldBe(cameraViewBefore); // no camera switch behind the About page
-        vm.IsTrimming.ShouldBeFalse();
+        vm.Trim.IsTrimming.ShouldBeFalse();
         vm.ShowAboutPage.ShouldBeTrue(); // the page stays open
     }
 
diff --git a/SentryDeck/MainWindow.xaml b/SentryDeck/MainWindow.xaml
index 9ad4bd2..bdfdbdb 100644
--- a/SentryDeck/MainWindow.xaml
+++ b/SentryDeck/MainWindow.xaml
@@ -75,10 +75,10 @@
                                     CornerRadius="2"
                                     IsHitTestVisible="False"
                                     Opacity="0.3"
-                                    Visibility="{Binding Data.HasSelection, Converter={local:BoolToVisibilityConverter}, Source={StaticResource VmProxy}}">
+                                    Visibility="{Binding Data.Trim.HasSelection, Converter={local:BoolToVisibilityConverter}, Source={StaticResource VmProxy}}">
                                 <Border.Margin>
                                     <MultiBinding Converter="{local:SeekOffsetConverter}">
-                                        <Binding Path="Data.SelectionStartPosition"
+                                        <Binding Path="Data.Trim.SelectionStartPosition"
                                                  Source="{StaticResource VmProxy}" />
                                         <Binding ElementName="SeekRail"
                                                  Path="ActualWidth" />
@@ -86,9 +86,9 @@
                                 </Border.Margin>
                                 <Border.Width>
                                     <MultiBinding Converter="{local:SelectionWidthConverter}">
-                                        <Binding Path="Data.SelectionStartPosition"
+                                        <Binding Path="Data.Trim.SelectionStartPosition"
                                                  Source="{StaticResource VmProxy}" />
-                                        <Binding Path="Data.SelectionEndPosition"
+                                        <Binding Path="Data.Trim.SelectionEndPosition"
                                                  Source="{StaticResource VmProxy}" />
                                         <Binding ElementName="SeekRail"
                                                  Path="ActualWidth" />
@@ -104,10 +104,10 @@
                                        IsHitTestVisible="False"
                                        RadiusX="1"
                                        RadiusY="1"
-                                       Visibility="{Binding Data.HasSelectionStart, Converter={local:BoolToVisibilityConverter}, Source={StaticResource VmProxy}}">
+                                       Visibility="{Binding Data.Trim.HasSelectionStart, Converter={local:BoolToVisibilityConverter}, Source={StaticResource VmProxy}}">
                                 <Rectangle.Margin>
                                     <MultiBinding Converter="{local:SeekOffsetConverter}">
-                                        <Binding Path="Data.SelectionStartPosition"
+                                        <Binding Path="Data.Trim.SelectionStartPosition"
                                                  Source="{StaticResource VmProxy}" />
                                         <Binding ElementName="SeekRail"
                                                  Path="ActualWidth" />
@@ -123,10 +123,10 @@
                                        IsHitTestVisible="False"
                                        RadiusX="1"
                                        RadiusY="1"
-                                       Visibility="{Binding Data.HasSelectionEnd, Converter={local:BoolToVisibilityConverter}, Source={StaticResource VmProxy}}">
+                                       Visibility="{Binding Data.Trim.HasSelectionEnd, Converter={local:BoolToVisibilityConverter}, Source={StaticResource VmProxy}}">
                                 <Rectangle.Margin>
                                     <MultiBinding Converter="{local:SeekOffsetConverter}">
-                                        <Binding Path="Data.SelectionEndPosition"
+                                        <Binding Path="Data.Trim.SelectionEndPosition"
                                                  Source="{StaticResource VmProxy}" />
                                         <Binding ElementName="SeekRail"
                                                  Path="ActualWidth" />
@@ -505,7 +505,7 @@
             </MenuItem>
             <!--  ±30s of front-camera footage around the event moment, stream-copied (no re-encode).  -->
             <MenuItem Header="Save event clip…"
-                      Command="{Binding PlacementTarget.Tag.SaveEventClipCommand, RelativeSource={RelativeSource AncestorType=ContextMenu}}"
+                      Command="{Binding PlacementTarget.Tag.Trim.SaveEventClipCommand, RelativeSource={RelativeSource AncestorType=ContextMenu}}"
                       CommandParameter="{Binding PlacementTarget.DataContext, RelativeSource={RelativeSource AncestorType=ContextMenu}}">
                 <MenuItem.Icon>
                     <TextBlock Text="&#xE792;" Style="{StaticResource AppGlyph}" />
@@ -1341,7 +1341,7 @@
                             Background="{DynamicResource LayerFillColorDefaultBrush}"
                             BorderBrush="{DynamicResource DividerStrokeColorDefaultBrush}"
                             BorderThickness="0,1,0,1"
-                            Visibility="{Binding IsTrimming, Converter={local:BoolToVisibilityConverter}}">
+                            Visibility="{Binding Trim.IsTrimming, Converter={local:BoolToVisibilityConverter}}">
                         <Grid>
                             <Grid.ColumnDefinitions>
                                 <ColumnDefinition Width="Auto" />
@@ -1367,7 +1367,7 @@
                             </StackPanel>
 
                             <Button Grid.Column="1"
-                                    Command="{Binding MarkSelectionStartCommand}"
+                                    Command="{Binding Trim.MarkSelectionStartCommand}"
                                     VerticalAlignment="Center"
                                     AutomationProperties.Name="Set start"
                                     Style="{StaticResource DefaultButtonStyle}"
@@ -1384,7 +1384,7 @@
                             </Button>
 
                             <Button Grid.Column="2"
-                                    Command="{Binding MarkSelectionEndCommand}"
+                                    Command="{Binding Trim.MarkSelectionEndCommand}"
                                     Margin="8,0,0,0"
                                     VerticalAlignment="Center"
                                     AutomationProperties.Name="Set end"
@@ -1403,14 +1403,14 @@
 
                             <!--  Live guidance: which step is next, then the selected length.  -->
                             <TextBlock Grid.Column="3"
-                                       Text="{Binding TrimHintText}"
+                                       Text="{Binding Trim.TrimHintText}"
                                        Margin="16,0"
                                        VerticalAlignment="Center"
                                        Foreground="{DynamicResource TextFillColorSecondaryBrush}"
                                        TextTrimming="CharacterEllipsis" />
 
                             <Button Grid.Column="4"
-                                    Command="{Binding ExportSelectionCommand}"
+                                    Command="{Binding Trim.ExportSelectionCommand}"
                                     VerticalAlignment="Center"
                                     AutomationProperties.Name="Export trimmed clip"
                                     Style="{StaticResource AccentButtonStyle}"
@@ -1425,7 +1425,7 @@
 
                             <Button Grid.Column="5"
                                     Content="Cancel"
-                                    Command="{Binding CancelTrimCommand}"
+                                    Command="{Binding Trim.CancelTrimCommand}"
                                     Margin="8,0,0,0"
                                     VerticalAlignment="Center"
                                     AutomationProperties.Name="Cancel trim"
@@ -1549,7 +1549,7 @@
                             </Button>
 
                             <!--  Opens the trim panel (above this bar) for cutting a shareable MP4.  -->
-                            <Button Command="{Binding ToggleTrimmingCommand}"
+                            <Button Command="{Binding Trim.ToggleTrimmingCommand}"
                                     Margin="6,0,0,0"
                                     VerticalAlignment="Center"
                                     AutomationProperties.Name="Trim clip"
diff --git a/SentryDeck/MainWindowViewModel.cs b/SentryDeck/MainWindowViewModel.cs
index 9685710..fb94bd4 100644
--- a/SentryDeck/MainWindowViewModel.cs
+++ b/SentryDeck/MainWindowViewModel.cs
@@ -1,38 +1,36 @@
 using System.ComponentModel;
-using System.Diagnostics;
-using System.Globalization;
-using System.IO;
-using System.Windows;
 using System.Windows.Input;
 using System.Windows.Threading;
 using CommunityToolkit.Mvvm.ComponentModel;
 using CommunityToolkit.Mvvm.Input;
-using Microsoft.VisualBasic.FileIO;
-using Microsoft.Win32;
 using Serilog;
 
 namespace SentryDeck;
 
 /// <summary>
-/// View-model for the main window: clip browsing, playback orchestration, update checks, FFmpeg prompts, and shell actions.
+/// View-model for the main window.
+/// It composes one view-model per feature (<see cref="Library"/>, <see cref="Playback"/>, <see cref="Trim"/>, <see cref="Cameras"/>, <see cref="Error"/>, <see cref="About"/>), wires them to each other, and owns what spans them: startup, the overlay covering the video area, the About page, and keyboard shortcuts.
 /// Holds no references to WPF controls; the view supplies the playback controller (via <see cref="MainWindowViewModel(Func{VideoPlayerController})"/>) and reacts to <see cref="SearchBoxFocusRequested"/> and <see cref="CameraViewsViewModel.SelectedCameraView"/> changes.
 /// </summary>
 public partial class MainWindowViewModel : ObservableObject
 {
     private readonly FlyleafRuntime _flyleafRuntime = new();
     private readonly Dispatcher _dispatcher;
-    private readonly IClipExporter _clipExporter;
-    private readonly Func<string, string> _savePathPicker;
-    private readonly IClipMediaSourceBuilder _exportMediaSourceBuilder;
     private bool _isInitialized;
     private bool _isDownloadingFFmpeg;
 
-    /// <param name="playerControllerFactory">Creates the playback controller (the view supplies one bound to its Flyleaf hosts).</param> <param name="clipLoader">Maps a dashcam root to its clips.
-    /// Defaults to scanning the filesystem; overridable for tests.</param> <param name="backgroundYield">Yields to the UI before a clip loads so the window stays responsive.
-    /// Overridable for tests.</param> <param name="clipExporter">Exports trimmed clip ranges.
-    /// Defaults to the FFmpeg-backed exporter; overridable for tests.</param> <param name="savePathPicker">Maps a suggested file name to the chosen save path (null = canceled).
-    /// Defaults to a save dialog; overridable for tests.</param> <param name="exportMediaSourceBuilder">Builds a media source for exporting a clip that isn't currently open.
-    /// Overridable for tests.</param> <param name="uiInvoker">Runs an action on the UI thread.
+    /// <param name="playerControllerFactory">Creates the playback controller (the view supplies one bound to its Flyleaf hosts).</param>
+    /// <param name="clipLoader">Maps a dashcam root to its clips.
+    /// Defaults to scanning the filesystem; overridable for tests.</param>
+    /// <param name="backgroundYield">Yields to the UI before a clip loads so the window stays responsive.
+    /// Overridable for tests.</param>
+    /// <param name="clipExporter">Exports trimmed clip ranges.
+    /// Defaults to the FFmpeg-backed exporter; overridable for tests.</param>
+    /// <param name="savePathPicker">Maps a suggested file name to the chosen save path (null = canceled).
+    /// Defaults to a save dialog; overridable for tests.</param>
+    /// <param name="exportMediaSourceBuilder">Builds a media source for exporting a clip that isn't currently open.
+    /// Overridable for tests.</param>
+    /// <param name="uiInvoker">Runs an action on the UI thread.
     /// Defaults to the dispatcher hop; overridable for tests, which have no pumped message loop to service it.</param>
     public MainWindowViewModel(
         Func<VideoPlayerController> playerControllerFactory,
@@ -43,10 +41,8 @@ public MainWindowViewModel(
         IClipMediaSourceBuilder exportMediaSourceBuilder = null,
         Action<Action> uiInvoker = null)
     {
-        _clipExporter = clipExporter ?? new ClipExporter(PackageManager.FindFFmpegDirectory);
-        _savePathPicker = savePathPicker ?? PickSavePathWithDialog;
-        _exportMediaSourceBuilder = exportMediaSourceBuilder ?? new FfconcatMediaSourceBuilder();
         _dispatcher = Dispatcher.CurrentDispatcher;
+
         Playback = new PlaybackViewModel(
             playerControllerFactory,
             backgroundYield ?? (async () => await Dispatcher.Yield(DispatcherPriority.Background)),
@@ -58,6 +54,13 @@ public MainWindowViewModel(
             Playback,
             Error,
             _dispatcher);
+        Trim = new TrimViewModel(
+            Playback,
+            Cameras,
+            Error,
+            clipExporter ?? new ClipExporter(PackageManager.FindFFmpegDirectory),
+            savePathPicker,
+            exportMediaSourceBuilder ?? new FfconcatMediaSourceBuilder());
 
         Error.PropertyChanged += (_, e) =>
         {
@@ -105,100 +108,28 @@ public MainWindowViewModel(
     /// </summary>
     public ClipLibraryViewModel Library { get; }
 
-    public bool ShowMainContent => !ShowAboutPage;
+    /// <summary>
+    /// The trim panel's in/out marks, and exporting a range or an event clip.
+    /// </summary>
+    public TrimViewModel Trim { get; }
 
-    // The full-screen overlay only covers the no-video states (scanning with no clip, error, empty); as a WPF sibling it can't draw over the Flyleaf video surface anyway.
-    // While a selected clip loads, the hosts stay visible and simply show black until the first frame decodes, with no loading screen flashing mid-playback.
-    public bool ShowStatusOverlay => (IsLoading && Library.SelectedClip is null) || Error.IsVisible || HasNoClipSelected;
+    public bool ShowMainContent => !ShowAboutPage;
 
     /// <summary>
     /// True while anything blocks the video pane: a clip scan, the FFmpeg download, or the selected clip loading.
     /// </summary>
     public bool IsLoading => Library.IsLoadingClips || _isDownloadingFFmpeg || Playback.IsLoading;
 
+    // The full-screen overlay only covers the no-video states (scanning with no clip, error, empty); as a WPF sibling it can't draw over the Flyleaf video surface anyway.
+    // While a selected clip loads, the hosts stay visible and simply show black until the first frame decodes, with no loading screen flashing mid-playback.
+    public bool ShowStatusOverlay => (IsLoading && Library.SelectedClip is null) || Error.IsVisible || HasNoClipSelected;
+
     public bool ShowVideoHosts => Library.SelectedClip is not null && !Error.IsVisible;
 
     public bool HasError => Error.IsVisible;
 
     public bool HasNoClipSelected => Library.SelectedClip is null && !IsLoading && !Error.IsVisible;
 
-    // --- Export selection (in/out marks on the seek bar, as 0..1 fractions like SeekPosition) ---
-    // Plain fields + an explicit notify helper (not ObservableProperty) because the pair changes together under shared invariants (start < end) and several derived properties hang off both.
-    private double? _selectionStart;
-    private double? _selectionEnd;
-
-    /// <summary>How much footage to keep on each side of the event moment in "Save event clip".</summary>
-    public static readonly TimeSpan EventClipPadding = TimeSpan.FromSeconds(30);
-
-    /// <summary>The selection start as a 0..1 fraction of the clip timeline (0 when unset; pair with <see cref="HasSelectionStart"/>).</summary>
-    public double SelectionStartPosition => _selectionStart ?? 0d;
-
-    /// <summary>The selection end as a 0..1 fraction of the clip timeline (0 when unset; pair with <see cref="HasSelectionEnd"/>).</summary>
-    public double SelectionEndPosition => _selectionEnd ?? 0d;
-
-    public bool HasSelectionStart => _selectionStart.HasValue;
-
-    public bool HasSelectionEnd => _selectionEnd.HasValue;
-
-    /// <summary>True when both marks are set (a complete, exportable range).</summary>
-    public bool HasSelection => _selectionStart.HasValue && _selectionEnd.HasValue;
-
-    public bool CanExportSelection => HasSelection && !IsExporting && Playback.CanSeek;
-
-    /// <summary>
-    /// True while the trim panel is open.
-    /// Opens explicitly (the Trim button) or implicitly (marking a point via I/O); closing it always discards the marks, so the panel and the selection can't drift apart.
-    /// </summary>
-    [ObservableProperty]
-    private bool _isTrimming;
-
-    /// <summary>
-    /// One-line guidance for the trim panel: walks the user through start → end → export, and shows the selected length once the range is complete.
-    /// </summary>
-    public string TrimHintText
-    {
-        get
-        {
-            if (HasSelection)
-            {
-                return $"{SelectionDurationText} selected — ready to export.";
-            }
-
-            if (HasSelectionStart)
-            {
-                return "Now play or scrub ahead to the end of your cut, then set the end.";
-            }
-
-            if (HasSelectionEnd)
-            {
-                return "Now play or scrub back to where your cut should begin, then set the start.";
-            }
-
-            return "Play or scrub to where your cut should begin, then set the start.";
-        }
-    }
-
-    /// <summary>Length of the marked range, e.g. "0:42" (empty until both marks are set).</summary>
-    public string SelectionDurationText
-    {
-        get
-        {
-            if (_selectionStart is not { } start || _selectionEnd is not { } end)
-            {
-                return string.Empty;
-            }
-
-            var duration = Playback.Duration;
-            return FormatTimeSpan(TimeSpan.FromSeconds((end - start) * duration.TotalSeconds));
-        }
-    }
-
-    [ObservableProperty]
-    [NotifyPropertyChangedFor(nameof(CanExportSelection))]
-    [NotifyCanExecuteChangedFor(nameof(ExportSelectionCommand))]
-    [NotifyCanExecuteChangedFor(nameof(SaveEventClipCommand))]
-    private bool _isExporting;
-
     [ObservableProperty]
     [NotifyPropertyChangedFor(nameof(ShowMainContent))]
     private bool _showAboutPage;
@@ -237,238 +168,53 @@ public void Shutdown()
     public void InitializePlayer() => Playback.InitializePlayer();
 
     /// <summary>
-    /// Marks the selection start at the current playhead.
-    /// A mark that would invert the range (start at or past the existing end) clears the other mark instead of silently swapping.
+    /// True for the shortcuts that focus the clip search box (Ctrl+F, F3, or F6).
+    /// Shared with the view's tunneling PreviewKeyDown so it works regardless of which control currently has focus.
     /// </summary>
-    [RelayCommand(CanExecute = nameof(CanSeek))]
-    private void MarkSelectionStart()
-    {
-        IsTrimming = true;
-        _selectionStart = Playback.SeekPosition;
-        if (_selectionEnd is { } end && end <= Playback.SeekPosition)
-        {
-            _selectionEnd = null;
-        }
-
-        NotifySelectionChanged();
-    }
-
-    /// <summary>Marks the selection end at the current playhead (see <see cref="MarkSelectionStart"/> for the invariant).</summary>
-    [RelayCommand(CanExecute = nameof(CanSeek))]
-    private void MarkSelectionEnd()
-    {
-        IsTrimming = true;
-        _selectionEnd = Playback.SeekPosition;
-        if (_selectionStart is { } start && start >= Playback.SeekPosition)
-        {
-            _selectionStart = null;
-        }
-
-        NotifySelectionChanged();
-    }
-
-    [RelayCommand(CanExecute = nameof(HasAnySelectionMark))]
-    private void ClearSelection()
-    {
-        _selectionStart = null;
-        _selectionEnd = null;
-        NotifySelectionChanged();
-    }
-
-    /// <summary>The control-bar Trim button: opens the trim panel, or cancels an open one.</summary>
-    [RelayCommand(CanExecute = nameof(CanSeek))]
-    private void ToggleTrimming()
-    {
-        if (IsTrimming)
-        {
-            CancelTrim();
-        }
-        else
-        {
-            IsTrimming = true;
-        }
-    }
-
-    /// <summary>Closes the trim panel and discards any marks.</summary>
-    [RelayCommand]
-    private void CancelTrim()
-    {
-        IsTrimming = false;
-        if (HasAnySelectionMark)
-        {
-            ClearSelection();
-        }
-    }
-
-    /// <summary>True when either mark is set (drives the clear affordance).</summary>
-    public bool HasAnySelectionMark => _selectionStart.HasValue || _selectionEnd.HasValue;
-
-    // The trim commands gate on the player being seekable.
-    private bool CanSeek => Playback.CanSeek;
-
-    // Everything downstream of CanSeek: the mark/export commands gate on it.
-    private void NotifyCanSeekChanged()
-    {
-        OnPropertyChanged(nameof(CanExportSelection));
-        OnPropertyChanged(nameof(SelectionDurationText)); // scales with Duration
-        OnPropertyChanged(nameof(TrimHintText));
-        MarkSelectionStartCommand.NotifyCanExecuteChanged();
-        MarkSelectionEndCommand.NotifyCanExecuteChanged();
-        ToggleTrimmingCommand.NotifyCanExecuteChanged();
-        ExportSelectionCommand.NotifyCanExecuteChanged();
-    }
-
-    private void NotifySelectionChanged()
-    {
-        OnPropertyChanged(nameof(SelectionStartPosition));
-        OnPropertyChanged(nameof(SelectionEndPosition));
-        OnPropertyChanged(nameof(HasSelectionStart));
-        OnPropertyChanged(nameof(HasSelectionEnd));
-        OnPropertyChanged(nameof(HasSelection));
-        OnPropertyChanged(nameof(HasAnySelectionMark));
-        OnPropertyChanged(nameof(CanExportSelection));
-        OnPropertyChanged(nameof(TrimHintText));
-        OnPropertyChanged(nameof(SelectionDurationText));
-        ClearSelectionCommand.NotifyCanExecuteChanged();
-        ExportSelectionCommand.NotifyCanExecuteChanged();
-    }
+    public static bool IsSearchFocusShortcut(Key key, ModifierKeys modifiers) =>
+        (key == Key.F && modifiers == ModifierKeys.Control) ||
+        ((key == Key.F3 || key == Key.F6) && modifiers == ModifierKeys.None);
 
-    [RelayCommand(CanExecute = nameof(CanExportSelection))]
-    private async Task ExportSelectionAsync()
+    /// <summary>Leaves the About page if shown and asks the view to focus the search box.</summary>
+    public void RequestSearchFocus()
     {
-        var clip = Playback.CurrentClip;
-        var mediaSource = Playback.OpenedMediaSource;
-        if (clip is null || mediaSource is null || mediaSource.Duration <= TimeSpan.Zero
-            || _selectionStart is not { } startFraction || _selectionEnd is not { } endFraction)
-        {
-            return;
-        }
-
-        var start = TimeSpan.FromSeconds(startFraction * mediaSource.Duration.TotalSeconds);
-        var end = TimeSpan.FromSeconds(endFraction * mediaSource.Duration.TotalSeconds);
-        var camera = Cameras.ExportCamera;
-        var defaultFileName = $"{clip.Name} {CameraNames.DisplayName(camera)} {FormatTimeSpanForFileName(start)}-{FormatTimeSpanForFileName(end)}.mp4";
-
-        await ExportAsync(clip, mediaSource, camera, start, end, defaultFileName);
+        ShowAboutPage = false;
+        SearchBoxFocusRequested?.Invoke(this, EventArgs.Empty);
     }
 
     /// <summary>
-    /// Exports the front-camera footage around the clip's event moment (±<see cref="EventClipPadding"/>) in one step, with no in/out marks needed.
-    /// Works from the clip list context menu even when the clip isn't the one currently playing (its media source is built on demand).
+    /// Handles an app-wide shortcut and reports synchronously whether the key was one.
+    /// The view calls this from a tunneling key handler and must mark the key handled before any await, or a focused button would also act on it (Space clicks whatever button was last clicked).
     /// </summary>
-    [RelayCommand(CanExecute = nameof(CanSaveEventClip))]
-    private async Task SaveEventClipAsync(CamClip clip)
+    public bool HandleKeyDown(Key key, ModifierKeys modifiers)
     {
-        if (clip?.Event is null || clip.Event.Timestamp == default || IsExporting)
-        {
-            return;
-        }
-
-        ClipMediaSource mediaSource;
-        try
-        {
-            mediaSource = Playback.CurrentClip == clip ? Playback.OpenedMediaSource : null;
-
-            // Building an unopened clip's source does real IO (probe every chunk, write ffconcat files) and can throw (drive unplugged, temp write fails).
-            // Unlike ExportSelectionAsync, nothing downstream caught it, so the fault escaped to the dispatcher; surface a normal "Export Failed" dialog instead.
-            mediaSource ??= await Task.Run(() => _exportMediaSourceBuilder.Build(clip));
-        }
-        catch (Exception ex)
-        {
-            Log.Error(ex, "Failed to build media source for event clip. ClipName={ClipName}; ClipPath={ClipPath}", clip.Name, clip.FullPath);
-            Error.Show("Export Failed", $"Could not export clip: {clip.Name}\n\nError: {ex.Message}");
-            return;
-        }
-
-        var eventTime = mediaSource.Duration > TimeSpan.Zero ? mediaSource.ToMediaTime(clip.Event.Timestamp) : null;
-        if (eventTime is null)
-        {
-            Error.Show("Export Failed", "The event moment isn't within this clip's saved footage.");
-            return;
-        }
-
-        var start = eventTime.Value - EventClipPadding;
-        if (start < TimeSpan.Zero)
-        {
-            start = TimeSpan.Zero;
-        }
-
-        var end = eventTime.Value + EventClipPadding;
-        if (end > mediaSource.Duration)
+        var action = ResolveKeyAction(key, modifiers);
+        if (action is null)
         {
-            end = mediaSource.Duration;
+            return false;
         }
 
-        await ExportAsync(clip, mediaSource, CameraNames.Front, start, end, $"{clip.Name} event.mp4");
+        _ = RunKeyActionAsync(action, key);
+        return true;
     }
 
-    private bool CanSaveEventClip(CamClip clip) =>
-        clip?.Event is not null && clip.Event.Timestamp != default && !IsExporting;
-
-    private async Task ExportAsync(CamClip clip, ClipMediaSource mediaSource, string camera, TimeSpan start, TimeSpan end, string defaultFileName)
+    /// <summary>Awaitable form of <see cref="HandleKeyDown"/> for callers (tests) that need the shortcut's work to have finished.</summary>
+    public async Task<bool> HandleKeyDownAsync(Key key, ModifierKeys modifiers)
     {
-        var outputPath = _savePathPicker(SanitizeFileName(defaultFileName));
-        if (string.IsNullOrEmpty(outputPath))
-        {
-            return;
-        }
-
-        IsExporting = true;
-
-        try
-        {
-            Log.Information(
-                "Exporting clip range. Clip={ClipName}; Camera={Camera}; Start={Start}; End={End}; Output={Output}",
-                clip.Name,
-                camera,
-                start,
-                end,
-                outputPath);
-            await _clipExporter.ExportAsync(new ClipExportRequest(clip, mediaSource, camera, start, end, outputPath));
-            RevealInExplorer(outputPath);
-        }
-        catch (OperationCanceledException)
-        {
-        }
-        catch (Exception ex)
-        {
-            Log.Error(ex, "Export failed. Clip={ClipName}; Camera={Camera}; Output={Output}", clip.Name, camera, outputPath);
-            Error.Show("Export Failed", $"Could not export clip: {clip.Name}\n\nError: {ex.Message}");
-        }
-        finally
+        var action = ResolveKeyAction(key, modifiers);
+        if (action is null)
         {
-            IsExporting = false;
+            return false;
         }
-    }
-
-    private static string PickSavePathWithDialog(string defaultFileName)
-    {
-        var dialog = new SaveFileDialog
-        {
-            Title = "Export clip",
-            FileName = defaultFileName,
-            DefaultExt = ".mp4",
-            Filter = "MP4 video|*.mp4",
-        };
 
-        return dialog.ShowDialog() == true ? dialog.FileName : null;
+        await action();
+        return true;
     }
 
-    /// <summary>Points Explorer at the exported file so it's immediately ready to share.
-    /// Overridable for tests.</summary>
-    internal Action<string> RevealInExplorer { get; set; } = path =>
-        Process.Start(new ProcessStartInfo("explorer.exe", $"/select,\"{path}\"") { UseShellExecute = true });
-
-    private static string FormatTimeSpanForFileName(TimeSpan ts) => FormatTimeSpan(ts).Replace(':', '.');
-
-    private static string SanitizeFileName(string name)
+    [RelayCommand]
+    private void ToggleAbout()
     {
-        foreach (var invalid in Path.GetInvalidFileNameChars())
-        {
-            name = name.Replace(invalid, '_');
-        }
-
-        return name;
+        ShowAboutPage = !ShowAboutPage;
     }
 
     [RelayCommand]
@@ -506,54 +252,14 @@ private async Task DownloadFFmpegAsync()
     private void SetDownloadingFFmpeg(bool value)
     {
         _isDownloadingFFmpeg = value;
-        OnPropertyChanged(nameof(IsLoading));
-        OnPropertyChanged(nameof(ShowStatusOverlay));
-        OnPropertyChanged(nameof(ShowVideoHosts));
-        OnPropertyChanged(nameof(HasNoClipSelected));
+        NotifyLoadingChanged();
     }
 
-    /// <summary>
-    /// True for the shortcuts that focus the clip search box (Ctrl+F, F3, or F6).
-    /// Shared with the view's tunneling PreviewKeyDown so it works regardless of which control currently has focus.
-    /// </summary>
-    public static bool IsSearchFocusShortcut(Key key, ModifierKeys modifiers) =>
-        (key == Key.F && modifiers == ModifierKeys.Control) ||
-        ((key == Key.F3 || key == Key.F6) && modifiers == ModifierKeys.None);
-
-    /// <summary>Leaves the About page if shown and asks the view to focus the search box.</summary>
-    public void RequestSearchFocus()
-    {
-        ShowAboutPage = false;
-        SearchBoxFocusRequested?.Invoke(this, EventArgs.Empty);
-    }
-
-    /// <summary>
-    /// Handles an app-wide shortcut and reports synchronously whether the key was one.
-    /// The view calls this from a tunneling key handler and must mark the key handled before any await, or a focused button would also act on it (Space clicks whatever button was last clicked).
-    /// </summary>
-    public bool HandleKeyDown(Key key, ModifierKeys modifiers)
-    {
-        var action = ResolveKeyAction(key, modifiers);
-        if (action is null)
-        {
-            return false;
-        }
-
-        _ = RunKeyActionAsync(action, key);
-        return true;
-    }
-
-    /// <summary>Awaitable form of <see cref="HandleKeyDown"/> for callers (tests) that need the shortcut's work to have finished.</summary>
-    public async Task<bool> HandleKeyDownAsync(Key key, ModifierKeys modifiers)
+    private void ShowFFmpegMissingError()
     {
-        var action = ResolveKeyAction(key, modifiers);
-        if (action is null)
-        {
-            return false;
-        }
-
-        await action();
-        return true;
+        Log.Debug("Showing FFmpeg missing prompt");
+        Error.ShowFFmpegDownloadButton = true;
+        Error.Show("FFmpeg Required", "FFmpeg is required to play clips. This will download about 80MB.", canDismiss: false);
     }
 
     private static async Task RunKeyActionAsync(Func<Task> action, Key key)
@@ -611,25 +317,25 @@ private Func<Task> ResolveKeyAction(Key key, ModifierKeys modifiers)
                 return () => Playback.JumpToEventCommand.ExecuteAsync(null);
             }
 
-            if (key == Key.I && CanSeek)
+            if (key == Key.I && Playback.CanSeek)
             {
-                return Run(MarkSelectionStart);
+                return Run(() => Trim.MarkSelectionStartCommand.Execute(null));
             }
 
-            if (key == Key.O && CanSeek)
+            if (key == Key.O && Playback.CanSeek)
             {
-                return Run(MarkSelectionEnd);
+                return Run(() => Trim.MarkSelectionEndCommand.Execute(null));
             }
 
-            if (key == Key.Escape && IsTrimming)
+            if (key == Key.Escape && Trim.IsTrimming)
             {
-                return Run(CancelTrim);
+                return Run(() => Trim.CancelTrimCommand.Execute(null));
             }
         }
 
-        if (key == Key.E && modifiers == ModifierKeys.Control && CanExportSelection)
+        if (key == Key.E && modifiers == ModifierKeys.Control && Trim.CanExportSelection)
         {
-            return ExportSelectionAsync;
+            return () => Trim.ExportSelectionCommand.ExecuteAsync(null);
         }
 
         // Shift+, / Shift+. (i.e. < / >) step the playback speed, YouTube-style.
@@ -655,8 +361,8 @@ private Func<Task> ResolveKeyAction(Key key, ModifierKeys modifiers)
         return key switch
         {
             Key.Space => Playback.TogglePlayPauseAsync,
-            Key.OemComma when modifiers == ModifierKeys.None && CanSeek => () => Playback.StepFrameAsync(forward: false),
-            Key.OemPeriod when modifiers == ModifierKeys.None && CanSeek => () => Playback.StepFrameAsync(forward: true),
+            Key.OemComma when modifiers == ModifierKeys.None && Playback.CanSeek => () => Playback.StepFrameAsync(forward: false),
+            Key.OemPeriod when modifiers == ModifierKeys.None && Playback.CanSeek => () => Playback.StepFrameAsync(forward: true),
             Key.Left when modifiers == ModifierKeys.Control => Playback.CanGoPrevious ? () => Playback.PreviousCommand.ExecuteAsync(null) : Run(() => { }),
             Key.Right when modifiers == ModifierKeys.Control => Playback.CanGoNext ? () => Playback.NextCommand.ExecuteAsync(null) : Run(() => { }),
             Key.Left => () => Playback.SeekRelativeAsync(TimeSpan.FromSeconds(-5)),
@@ -671,45 +377,47 @@ static Func<Task> Run(Action action) => () =>
         };
     }
 
-    private static string FormatTimeSpan(TimeSpan ts) => PlaybackViewModel.FormatTimeSpan(ts);
-
-    private void OnPlaybackPropertyChanged(object sender, PropertyChangedEventArgs e)
+    private void OnLibraryPropertyChanged(object sender, PropertyChangedEventArgs e)
     {
         switch (e.PropertyName)
         {
-            case nameof(PlaybackViewModel.IsLoading):
-                OnPropertyChanged(nameof(IsLoading));
+            case nameof(ClipLibraryViewModel.SelectedClip):
+                OnSelectedClipChanged(Library.SelectedClip);
+                OnPropertyChanged(nameof(HasNoClipSelected));
                 OnPropertyChanged(nameof(ShowStatusOverlay));
                 OnPropertyChanged(nameof(ShowVideoHosts));
-                OnPropertyChanged(nameof(HasNoClipSelected));
                 break;
 
-            case nameof(PlaybackViewModel.CanSeek):
-                NotifyCanSeekChanged();
+            case nameof(ClipLibraryViewModel.IsLoadingClips):
+                NotifyLoadingChanged();
                 break;
+        }
+    }
 
-            case nameof(PlaybackViewModel.OpenedMediaSource):
-                // A rebuild can reshape the timeline (chunks excluded during recovery), so in/out fractions marked against the old timeline no longer point at the same footage.
-                if (HasAnySelectionMark)
-                {
-                    ClearSelection();
-                }
-
-                break;
+    private void OnPlaybackPropertyChanged(object sender, PropertyChangedEventArgs e)
+    {
+        if (e.PropertyName == nameof(PlaybackViewModel.IsLoading))
+        {
+            NotifyLoadingChanged();
         }
     }
 
-    private void ShowFFmpegMissingError()
+    private void OnSelectedClipChanged(CamClip value)
     {
-        Log.Debug("Showing FFmpeg missing prompt");
-        Error.ShowFFmpegDownloadButton = true;
-        Error.Show("FFmpeg Required", "FFmpeg is required to play clips. This will download about 80MB.", canDismiss: false);
+        Cameras.ShowCamerasOf(value);
+
+        // In/out marks are fractions of the previous clip's timeline; they mean nothing on the new one, and a trim panel guiding a cut of the old clip would now be lying.
+        Trim.CancelTrimCommand.Execute(null);
+
+        Playback.Select(value);
     }
 
-    [RelayCommand]
-    private void ToggleAbout()
+    private void NotifyLoadingChanged()
     {
-        ShowAboutPage = !ShowAboutPage;
+        OnPropertyChanged(nameof(IsLoading));
+        OnPropertyChanged(nameof(ShowStatusOverlay));
+        OnPropertyChanged(nameof(ShowVideoHosts));
+        OnPropertyChanged(nameof(HasNoClipSelected));
     }
 
     private void InvokeOnDispatcher(Action action)
@@ -723,34 +431,4 @@ private void InvokeOnDispatcher(Action action)
         // Never block the caller: a synchronous hop from a background thread while the UI thread waits on that thread is a deadlock.
         _dispatcher.BeginInvoke(action);
     }
-
-    private void OnLibraryPropertyChanged(object sender, PropertyChangedEventArgs e)
-    {
-        switch (e.PropertyName)
-        {
-            case nameof(ClipLibraryViewModel.SelectedClip):
-                OnSelectedClipChanged(Library.SelectedClip);
-                OnPropertyChanged(nameof(HasNoClipSelected));
-                OnPropertyChanged(nameof(ShowStatusOverlay));
-                OnPropertyChanged(nameof(ShowVideoHosts));
-                break;
-
-            case nameof(ClipLibraryViewModel.IsLoadingClips):
-                OnPropertyChanged(nameof(IsLoading));
-                OnPropertyChanged(nameof(ShowStatusOverlay));
-                OnPropertyChanged(nameof(ShowVideoHosts));
-                OnPropertyChanged(nameof(HasNoClipSelected));
-                break;
-        }
-    }
-
-    private void OnSelectedClipChanged(CamClip value)
-    {
-        Cameras.ShowCamerasOf(value);
-
-        // In/out marks are fractions of the previous clip's timeline; they mean nothing on the new one, and a trim panel guiding a cut of the old clip would now be lying.
-        CancelTrim();
-
-        Playback.Select(value);
-    }
 }
diff --git a/SentryDeck/ViewModels/TrimViewModel.cs b/SentryDeck/ViewModels/TrimViewModel.cs
new file mode 100644
index 0000000..2259714
--- /dev/null
+++ b/SentryDeck/ViewModels/TrimViewModel.cs
@@ -0,0 +1,372 @@
+using System.ComponentModel;
+using System.Diagnostics;
+using System.IO;
+using CommunityToolkit.Mvvm.ComponentModel;
+using CommunityToolkit.Mvvm.Input;
+using Microsoft.Win32;
+using Serilog;
+
+namespace SentryDeck;
+
+/// <summary>
+/// Cutting a clip down to share it: the trim panel's in/out marks on the seek bar, and exporting either the marked range or the footage around an event.
+/// </summary>
+public sealed partial class TrimViewModel : ObservableObject
+{
+    /// <summary>How much footage to keep on each side of the event moment in "Save event clip".</summary>
+    public static readonly TimeSpan EventClipPadding = TimeSpan.FromSeconds(30);
+
+    private readonly PlaybackViewModel _playback;
+    private readonly CameraViewsViewModel _cameras;
+    private readonly ErrorOverlayViewModel _error;
+    private readonly IClipExporter _clipExporter;
+    private readonly Func<string, string> _savePathPicker;
+    private readonly IClipMediaSourceBuilder _exportMediaSourceBuilder;
+
+    // --- Export selection (in/out marks on the seek bar, as 0..1 fractions like SeekPosition) ---
+    // Plain fields + an explicit notify helper (not ObservableProperty) because the pair changes together under shared invariants (start < end) and several derived properties hang off both.
+    private double? _selectionStart;
+    private double? _selectionEnd;
+
+    /// <param name="playback">Supplies the playhead the marks are set at, and the open clip an export reads from.</param>
+    /// <param name="cameras">Decides which camera a range export uses.</param>
+    /// <param name="error">Where export failures are reported.</param>
+    /// <param name="clipExporter">Exports trimmed clip ranges.</param>
+    /// <param name="savePathPicker">Maps a suggested file name to the chosen save path (null = canceled).</param>
+    /// <param name="exportMediaSourceBuilder">Builds a media source for exporting a clip that isn't currently open.</param>
+    public TrimViewModel(
+        PlaybackViewModel playback,
+        CameraViewsViewModel cameras,
+        ErrorOverlayViewModel error,
+        IClipExporter clipExporter,
+        Func<string, string> savePathPicker,
+        IClipMediaSourceBuilder exportMediaSourceBuilder)
+    {
+        _playback = playback;
+        _cameras = cameras;
+        _error = error;
+        _clipExporter = clipExporter;
+        _savePathPicker = savePathPicker ?? PickSavePathWithDialog;
+        _exportMediaSourceBuilder = exportMediaSourceBuilder;
+
+        _playback.PropertyChanged += OnPlaybackPropertyChanged;
+    }
+
+    /// <summary>The selection start as a 0..1 fraction of the clip timeline (0 when unset; pair with <see cref="HasSelectionStart"/>).</summary>
+    public double SelectionStartPosition => _selectionStart ?? 0d;
+
+    /// <summary>The selection end as a 0..1 fraction of the clip timeline (0 when unset; pair with <see cref="HasSelectionEnd"/>).</summary>
+    public double SelectionEndPosition => _selectionEnd ?? 0d;
+
+    public bool HasSelectionStart => _selectionStart.HasValue;
+
+    public bool HasSelectionEnd => _selectionEnd.HasValue;
+
+    /// <summary>True when both marks are set (a complete, exportable range).</summary>
+    public bool HasSelection => _selectionStart.HasValue && _selectionEnd.HasValue;
+
+    /// <summary>True when either mark is set (drives the clear affordance).</summary>
+    public bool HasAnySelectionMark => _selectionStart.HasValue || _selectionEnd.HasValue;
+
+    public bool CanExportSelection => HasSelection && !IsExporting && CanSeek;
+
+    /// <summary>
+    /// One-line guidance for the trim panel: walks the user through start → end → export, and shows the selected length once the range is complete.
+    /// </summary>
+    public string TrimHintText
+    {
+        get
+        {
+            if (HasSelection)
+            {
+                return $"{SelectionDurationText} selected — ready to export.";
+            }
+
+            if (HasSelectionStart)
+            {
+                return "Now play or scrub ahead to the end of your cut, then set the end.";
+            }
+
+            if (HasSelectionEnd)
+            {
+                return "Now play or scrub back to where your cut should begin, then set the start.";
+            }
+
+            return "Play or scrub to where your cut should begin, then set the start.";
+        }
+    }
+
+    /// <summary>Length of the marked range, e.g. "0:42" (empty until both marks are set).</summary>
+    public string SelectionDurationText
+    {
+        get
+        {
+            if (_selectionStart is not { } start || _selectionEnd is not { } end)
+            {
+                return string.Empty;
+            }
+
+            var duration = _playback.Duration;
+            return PlaybackViewModel.FormatTimeSpan(TimeSpan.FromSeconds((end - start) * duration.TotalSeconds));
+        }
+    }
+
+    /// <summary>
+    /// True while the trim panel is open.
+    /// Opens explicitly (the Trim button) or implicitly (marking a point via I/O); closing it always discards the marks, so the panel and the selection can't drift apart.
+    /// </summary>
+    [ObservableProperty]
+    private bool _isTrimming;
+
+    [ObservableProperty]
+    [NotifyPropertyChangedFor(nameof(CanExportSelection))]
+    [NotifyCanExecuteChangedFor(nameof(ExportSelectionCommand))]
+    [NotifyCanExecuteChangedFor(nameof(SaveEventClipCommand))]
+    private bool _isExporting;
+
+    /// <summary>Points Explorer at the exported file so it's immediately ready to share.
+    /// Overridable for tests.</summary>
+    internal Action<string> RevealInExplorer { get; set; } = path =>
+        Process.Start(new ProcessStartInfo("explorer.exe", $"/select,\"{path}\"") { UseShellExecute = true });
+
+    // The marks and the trim panel need a seekable player.
+    private bool CanSeek => _playback.CanSeek;
+
+    /// <summary>
+    /// Marks the selection start at the current playhead.
+    /// A mark that would invert the range (start at or past the existing end) clears the other mark instead of silently swapping.
+    /// </summary>
+    [RelayCommand(CanExecute = nameof(CanSeek))]
+    private void MarkSelectionStart()
+    {
+        IsTrimming = true;
+        _selectionStart = _playback.SeekPosition;
+        if (_selectionEnd is { } end && end <= _playback.SeekPosition)
+        {
+            _selectionEnd = null;
+        }
+
+        NotifySelectionChanged();
+    }
+
+    /// <summary>Marks the selection end at the current playhead (see <see cref="MarkSelectionStart"/> for the invariant).</summary>
+    [RelayCommand(CanExecute = nameof(CanSeek))]
+    private void MarkSelectionEnd()
+    {
+        IsTrimming = true;
+        _selectionEnd = _playback.SeekPosition;
+        if (_selectionStart is { } start && start >= _playback.SeekPosition)
+        {
+            _selectionStart = null;
+        }
+
+        NotifySelectionChanged();
+    }
+
+    [RelayCommand(CanExecute = nameof(HasAnySelectionMark))]
+    private void ClearSelection()
+    {
+        _selectionStart = null;
+        _selectionEnd = null;
+        NotifySelectionChanged();
+    }
+
+    /// <summary>The control-bar Trim button: opens the trim panel, or cancels an open one.</summary>
+    [RelayCommand(CanExecute = nameof(CanSeek))]
+    private void ToggleTrimming()
+    {
+        if (IsTrimming)
+        {
+            CancelTrim();
+        }
+        else
+        {
+            IsTrimming = true;
+        }
+    }
+
+    /// <summary>Closes the trim panel and discards any marks.</summary>
+    [RelayCommand]
+    private void CancelTrim()
+    {
+        IsTrimming = false;
+        if (HasAnySelectionMark)
+        {
+            ClearSelection();
+        }
+    }
+
+    [RelayCommand(CanExecute = nameof(CanExportSelection))]
+    private async Task ExportSelectionAsync()
+    {
+        var clip = _playback.CurrentClip;
+        var mediaSource = _playback.OpenedMediaSource;
+        if (clip is null || mediaSource is null || mediaSource.Duration <= TimeSpan.Zero
+            || _selectionStart is not { } startFraction || _selectionEnd is not { } endFraction)
+        {
+            return;
+        }
+
+        var start = TimeSpan.FromSeconds(startFraction * mediaSource.Duration.TotalSeconds);
+        var end = TimeSpan.FromSeconds(endFraction * mediaSource.Duration.TotalSeconds);
+        var camera = _cameras.ExportCamera;
+        var defaultFileName = $"{clip.Name} {CameraNames.DisplayName(camera)} {FormatTimeSpanForFileName(start)}-{FormatTimeSpanForFileName(end)}.mp4";
+
+        await ExportAsync(clip, mediaSource, camera, start, end, defaultFileName);
+    }
+
+    /// <summary>
+    /// Exports the front-camera footage around the clip's event moment (±<see cref="EventClipPadding"/>) in one step, with no in/out marks needed.
+    /// Works from the clip list context menu even when the clip isn't the one currently playing (its media source is built on demand).
+    /// </summary>
+    [RelayCommand(CanExecute = nameof(CanSaveEventClip))]
+    private async Task SaveEventClipAsync(CamClip clip)
+    {
+        if (clip?.Event is null || clip.Event.Timestamp == default || IsExporting)
+        {
+            return;
+        }
+
+        ClipMediaSource mediaSource;
+        try
+        {
+            mediaSource = _playback.CurrentClip == clip ? _playback.OpenedMediaSource : null;
+
+            // Building an unopened clip's source does real IO (probe every chunk, write ffconcat files) and can throw (drive unplugged, temp write fails).
+            // Unlike ExportSelectionAsync, nothing downstream caught it, so the fault escaped to the dispatcher; surface a normal "Export Failed" dialog instead.
+            mediaSource ??= await Task.Run(() => _exportMediaSourceBuilder.Build(clip));
+        }
+        catch (Exception ex)
+        {
+            Log.Error(ex, "Failed to build media source for event clip. ClipName={ClipName}; ClipPath={ClipPath}", clip.Name, clip.FullPath);
+            _error.Show("Export Failed", $"Could not export clip: {clip.Name}\n\nError: {ex.Message}");
+            return;
+        }
+
+        var eventTime = mediaSource.Duration > TimeSpan.Zero ? mediaSource.ToMediaTime(clip.Event.Timestamp) : null;
+        if (eventTime is null)
+        {
+            _error.Show("Export Failed", "The event moment isn't within this clip's saved footage.");
+            return;
+        }
+
+        var start = eventTime.Value - EventClipPadding;
+        if (start < TimeSpan.Zero)
+        {
+            start = TimeSpan.Zero;
+        }
+
+        var end = eventTime.Value + EventClipPadding;
+        if (end > mediaSource.Duration)
+        {
+            end = mediaSource.Duration;
+        }
+
+        await ExportAsync(clip, mediaSource, CameraNames.Front, start, end, $"{clip.Name} event.mp4");
+    }
+
+    private bool CanSaveEventClip(CamClip clip) =>
+        clip?.Event is not null && clip.Event.Timestamp != default && !IsExporting;
+
+    private async Task ExportAsync(CamClip clip, ClipMediaSource mediaSource, string camera, TimeSpan start, TimeSpan end, string defaultFileName)
+    {
+        var outputPath = _savePathPicker(SanitizeFileName(defaultFileName));
+        if (string.IsNullOrEmpty(outputPath))
+        {
+            return;
+        }
+
+        IsExporting = true;
+
+        try
+        {
+            Log.Information(
+                "Exporting clip range. Clip={ClipName}; Camera={Camera}; Start={Start}; End={End}; Output={Output}",
+                clip.Name,
+                camera,
+                start,
+                end,
+                outputPath);
+            await _clipExporter.ExportAsync(new ClipExportRequest(clip, mediaSource, camera, start, end, outputPath));
+            RevealInExplorer(outputPath);
+        }
+        catch (OperationCanceledException)
+        {
+        }
+        catch (Exception ex)
+        {
+            Log.Error(ex, "Export failed. Clip={ClipName}; Camera={Camera}; Output={Output}", clip.Name, camera, outputPath);
+            _error.Show("Export Failed", $"Could not export clip: {clip.Name}\n\nError: {ex.Message}");
+        }
+        finally
+        {
+            IsExporting = false;
+        }
+    }
+
+    private static string PickSavePathWithDialog(string defaultFileName)
+    {
+        var dialog = new SaveFileDialog
+        {
+            Title = "Export clip",
+            FileName = defaultFileName,
+            DefaultExt = ".mp4",
+            Filter = "MP4 video|*.mp4",
+        };
+
+        return dialog.ShowDialog() == true ? dialog.FileName : null;
+    }
+
+    private static string FormatTimeSpanForFileName(TimeSpan ts) => PlaybackViewModel.FormatTimeSpan(ts).Replace(':', '.');
+
+    private static string SanitizeFileName(string name)
+    {
+        foreach (var invalid in Path.GetInvalidFileNameChars())
+        {
+            name = name.Replace(invalid, '_');
+        }
+
+        return name;
+    }
+
+    private void OnPlaybackPropertyChanged(object sender, PropertyChangedEventArgs e)
+    {
+        switch (e.PropertyName)
+        {
+            case nameof(PlaybackViewModel.CanSeek):
+                // Everything downstream of CanSeek: the mark/export commands gate on it, and the selected length scales with the clip's duration.
+                OnPropertyChanged(nameof(CanExportSelection));
+                OnPropertyChanged(nameof(SelectionDurationText));
+                OnPropertyChanged(nameof(TrimHintText));
+                MarkSelectionStartCommand.NotifyCanExecuteChanged();
+                MarkSelectionEndCommand.NotifyCanExecuteChanged();
+                ToggleTrimmingCommand.NotifyCanExecuteChanged();
+                ExportSelectionCommand.NotifyCanExecuteChanged();
+                break;
+
+            case nameof(PlaybackViewModel.OpenedMediaSource):
+                // A rebuild can reshape the timeline (chunks excluded during recovery), so in/out fractions marked against the old timeline no longer point at the same footage.
+                if (HasAnySelectionMark)
+                {
+                    ClearSelection();
+                }
+
+                break;
+        }
+    }
+
+    private void NotifySelectionChanged()
+    {
+        OnPropertyChanged(nameof(SelectionStartPosition));
+        OnPropertyChanged(nameof(SelectionEndPosition));
+        OnPropertyChanged(nameof(HasSelectionStart));
+        OnPropertyChanged(nameof(HasSelectionEnd));
+        OnPropertyChanged(nameof(HasSelection));
+        OnPropertyChanged(nameof(HasAnySelectionMark));
+        OnPropertyChanged(nameof(CanExportSelection));
+        OnPropertyChanged(nameof(TrimHintText));
+        OnPropertyChanged(nameof(SelectionDurationText));
+        ClearSelectionCommand.NotifyCanExecuteChanged();
+        ExportSelectionCommand.NotifyCanExecuteChanged();
+    }
+}

From ea3a2cfa54a0a053645f2c52ca651832586962cb Mon Sep 17 00:00:00 2001
From: Daniel Chalmers <daniel.chalmers@outlook.com>
Date: Thu, 24 Sep 2026 07:59:38 -0500
Subject: [PATCH 8/8] Test the wiring between the split view-models

Three connections now cross view-model boundaries and had no direct test:
- The player reports clip changes back to the list, so Next moves the list selection.
- The loading overlay follows the clip scan, not only clip loading, now that IsLoading combines the scan, the FFmpeg download, and playback.
- The trim marks are dropped when recovery rebuilds a clip's media, now that TrimViewModel follows PlaybackViewModel itself.

Each test was checked to fail with its wiring removed.
---
 .../MainWindowViewModelTests.Clips.cs         | 29 +++++++++++++++++++
 .../MainWindowViewModelTests.Playback.cs      | 23 +++++++++++++++
 .../MainWindowViewModelTests.Trimming.cs      | 22 ++++++++++++++
 3 files changed, 74 insertions(+)

diff --git a/SentryDeck.Tests/MainWindowViewModelTests.Clips.cs b/SentryDeck.Tests/MainWindowViewModelTests.Clips.cs
index c853c75..d0ee1cd 100644
--- a/SentryDeck.Tests/MainWindowViewModelTests.Clips.cs
+++ b/SentryDeck.Tests/MainWindowViewModelTests.Clips.cs
@@ -374,4 +374,33 @@ public async Task FilteredClips_NoMatch_IsEmpty()
 
         vm.Library.FilteredClips.ShouldBeEmpty();
     }
+
+    [Fact]
+    public async Task LoadClipsAsync_WhileTheScanRuns_ShowsTheLoadingOverlay()
+    {
+        // Loading is shared by the scan, the FFmpeg download, and clip loading; the overlay has to follow the scan even though playback isn't loading anything.
+        using var scanGate = new ManualResetEventSlim();
+        var vm = new MainWindowViewModel(() => null!, clipLoader: _ =>
+        {
+            scanGate.Wait();
+            return TestClips.Create(2);
+        });
+        var changed = new List<string>();
+        vm.PropertyChanged += (_, e) => changed.Add(e.PropertyName);
+
+        var load = vm.Library.LoadClipsAsync(["root"]);
+
+        vm.IsLoading.ShouldBeTrue();
+        vm.ShowStatusOverlay.ShouldBeTrue();
+        vm.HasNoClipSelected.ShouldBeFalse();
+        changed.ShouldContain(nameof(MainWindowViewModel.IsLoading));
+        changed.ShouldContain(nameof(MainWindowViewModel.ShowStatusOverlay));
+
+        scanGate.Set();
+        await load;
+
+        vm.IsLoading.ShouldBeFalse();
+        vm.HasNoClipSelected.ShouldBeTrue();
+        vm.Library.ClipCount.ShouldBe(2);
+    }
 }
diff --git a/SentryDeck.Tests/MainWindowViewModelTests.Playback.cs b/SentryDeck.Tests/MainWindowViewModelTests.Playback.cs
index 6d93b77..e0dc00b 100644
--- a/SentryDeck.Tests/MainWindowViewModelTests.Playback.cs
+++ b/SentryDeck.Tests/MainWindowViewModelTests.Playback.cs
@@ -223,4 +223,27 @@ public void StopCommand_WhileASelectionIsWaitingToLoad_KeepsItFromPlaying()
         controller.IsPlaying.ShouldBeFalse();
         vm.IsLoading.ShouldBeFalse();
     }
+
+    [Fact]
+    public void NextCommand_MovesTheListSelectionToTheNextClip()
+    {
+        // The player reports clip changes back to the clip list; without that the list would keep highlighting the clip it left.
+        using var first = TestClipFiles.Create(chunkCount: 1);
+        using var second = TestClipFiles.Create(chunkCount: 1);
+        var front = new FakeCameraPlayer();
+        var controller = BuildFourCameraController(front);
+        controller.LoadClips([first.Clip, second.Clip]);
+        var vm = new MainWindowViewModel(() => controller, backgroundYield: () => Task.CompletedTask, uiInvoker: action => action());
+        vm.InitializePlayer();
+        vm.Library.SelectedClip = first.Clip;
+        RunPinnedToTestThread(controller.WhenIdleAsync);
+
+        RunPinnedToTestThread(() => vm.Playback.NextCommand.ExecuteAsync(null));
+        RunPinnedToTestThread(controller.WhenIdleAsync);
+
+        vm.Library.SelectedClip.ShouldBe(second.Clip);
+        vm.Playback.NowPlayingClip.ShouldBe(second.Clip);
+        controller.CurrentClip.ShouldBe(second.Clip);
+        front.Count("open").ShouldBe(2);
+    }
 }
diff --git a/SentryDeck.Tests/MainWindowViewModelTests.Trimming.cs b/SentryDeck.Tests/MainWindowViewModelTests.Trimming.cs
index a6c3443..1f54d01 100644
--- a/SentryDeck.Tests/MainWindowViewModelTests.Trimming.cs
+++ b/SentryDeck.Tests/MainWindowViewModelTests.Trimming.cs
@@ -440,4 +440,26 @@ public void ChangingSpeed_FlowsToTheController()
 
         controller.PlaybackSpeed.ShouldBe(4.0);
     }
+
+    [Fact]
+    public void TrimMarks_WhenRecoveryRebuildsTheClipsMedia_AreDropped()
+    {
+        // Recovery from a corrupt chunk excludes footage and shrinks the timeline, so fractions marked against the old timeline would point at different moments.
+        using var clipFiles = TestClipFiles.Create(chunkCount: 3);
+        var (vm, controller, front) = CreateViewModelWithOpenedClip(clipFiles.Clip, uiInvoker: action => action());
+        RunPinnedToTestThread(controller.PauseAsync);
+        vm.Playback.SeekPosition = 0.2;
+        vm.Trim.MarkSelectionStartCommand.Execute(null);
+        vm.Playback.SeekPosition = 0.4;
+        vm.Trim.MarkSelectionEndCommand.Execute(null);
+        vm.Trim.HasSelection.ShouldBeTrue();
+
+        // Ending 90s into 180s of footage makes recovery exclude the middle chunk and reopen a 120s timeline.
+        front.RaisePositionChanged(TimeSpan.FromSeconds(90));
+        front.RaiseEnded();
+        RunPinnedToTestThread(controller.WhenIdleAsync);
+
+        controller.Duration.ShouldBe(TimeSpan.FromMinutes(2));
+        vm.Trim.HasAnySelectionMark.ShouldBeFalse();
+    }
 }