Groundwork: split device.rs into transport and enumeration

.github/workflows/ci.yml

@@ -68,7 +68,7 @@ jobs:
         with:
           persist-credentials: false
       - run: rustup toolchain install "$RUSTUP_TOOLCHAIN" --profile minimal --component clippy --no-self-update
-      - run: cargo clippy --all-targets --locked -- -D warnings
+      - run: cargo clippy --workspace --all-targets --locked -- -D warnings
 
   test:
     needs: changes
@@ -79,7 +79,7 @@ jobs:
         with:
           persist-credentials: false
       - run: rustup toolchain install "$RUSTUP_TOOLCHAIN" --profile minimal --no-self-update
-      - run: cargo test --locked
+      - run: cargo test --workspace --locked
 
   # Builds and tests with the oldest Rust that Cargo.toml's rust-version claims.
   msrv:
@@ -94,7 +94,7 @@ jobs:
           msrv=$(sed -n 's/^rust-version = "\(.*\)"/\1/p' Cargo.toml)
           test -n "$msrv"
           rustup toolchain install "$msrv" --profile minimal --no-self-update
-          cargo "+$msrv" test --locked
+          cargo "+$msrv" test --workspace --locked
 
   # The one check the main ruleset requires. Code changes need fmt, clippy, test and msrv to
   # succeed; docs-only changes need them skipped. Anything else fails.

.github/workflows/release.yml

@@ -22,6 +22,7 @@ on:
       - scripts/**
       - Cargo.toml
       - Cargo.lock
+      - crates/*/Cargo.toml
       - README.md
       - CHANGELOG.md
       - LICENSE
@@ -115,13 +116,13 @@ jobs:
           rustup toolchain install "$RUSTUP_TOOLCHAIN" --profile minimal
           --component rustfmt --component clippy --no-self-update
       - run: cargo fmt --check
-      - run: cargo clippy --all-targets --locked -- -D warnings
-      - run: cargo test --locked
+      - run: cargo clippy --workspace --all-targets --locked -- -D warnings
+      - run: cargo test --workspace --locked
       - run: |
           msrv=$(sed -n 's/^rust-version = "\(.*\)"/\1/p' Cargo.toml)
           test -n "$msrv"
           rustup toolchain install "$msrv" --profile minimal --no-self-update
-          cargo "+$msrv" test --locked
+          cargo "+$msrv" test --workspace --locked
 
   # One job per package format and architecture: a failure reruns only that job.
   binary:
@@ -200,7 +201,7 @@ jobs:
           mkdir dist
           # no rebuild: package the binary from the binary job (artifacts drop the mode)
           chmod +x target/release/obsbot4linux
-          cargo deb --no-build --deb-revision "" -o "dist/obsbot4linux_${ver}_$DEB.deb"
+          cargo deb -p obsbot4linux --no-build --deb-revision "" -o "dist/obsbot4linux_${ver}_$DEB.deb"
       - uses: actions/upload-artifact@cf430e030ddbb5b0abf93d22962f4752f3646cd9 # v7.0.2
         with:
           name: dist-deb-${{ matrix.arch }}
@@ -237,7 +238,7 @@ jobs:
           ver=$VER
           mkdir dist
           chmod +x target/release/obsbot4linux
-          cargo generate-rpm -o "dist/obsbot4linux-$ver-1.$ARCH.rpm"
+          cargo generate-rpm -p crates/obsbot4linux -o "dist/obsbot4linux-$ver-1.$ARCH.rpm"
       - uses: actions/upload-artifact@cf430e030ddbb5b0abf93d22962f4752f3646cd9 # v7.0.2
         with:
           name: dist-rpm-${{ matrix.arch }}
@@ -276,10 +277,60 @@ jobs:
           path: dist/*
           if-no-files-found: error
 
+  # Lists the files of every package and compares the list with packaging/contents.txt, so that
+  # a change to what a package holds shows up in review. A release needs it too.
+  contents:
+    needs: [version, binary, deb, rpm, arch]
+    runs-on: ubuntu-22.04
+    timeout-minutes: 10
+    steps:
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+        with:
+          persist-credentials: false
+      - uses: actions/download-artifact@9000827ccba6bdab643e8b6fd33ac0654aef8333 # v8.0.2
+        with:
+          path: dist
+          pattern: dist-*
+          merge-multiple: true
+      - run: sudo apt-get install -y --no-install-recommends libarchive-tools
+      # [profile.release] strip = true must reach every package (cargo ignores a member
+      # manifest's profile, and the file list alone would not show it)
+      - name: The packaged binaries are stripped
+        run: |
+          for pkg in dist/obsbot4linux*; do
+            case $pkg in
+            *.deb) bsdtar -xOf "$pkg" 'data.tar*' > payload ;;
+            *) cp "$pkg" payload ;;
+            esac
+            bin=$(bsdtar -tf payload | grep -E '(usr/bin|-linux)/obsbot4linux$')
+            bsdtar -xOf payload "$bin" > obsbot4linux.bin
+            info=$(file -b obsbot4linux.bin)
+            echo "$pkg: $info"
+            case $info in
+            *', stripped') ;;
+            *) echo "::error::$pkg ships an unstripped binary"; exit 1 ;;
+            esac
+          done
+          rm -f payload obsbot4linux.bin
+      - name: Compare the package contents
+        env:
+          VER: ${{ needs.version.outputs.ver }}
+        run: |
+          scripts/package-contents.sh dist "$VER" > contents.txt
+          cat contents.txt
+          diff -u packaging/contents.txt contents.txt
+      # the list itself, also when it differs, to update packaging/contents.txt from
+      - if: always()
+        uses: actions/upload-artifact@cf430e030ddbb5b0abf93d22962f4752f3646cd9 # v7.0.2
+        with:
+          name: package-contents
+          path: contents.txt
+          if-no-files-found: error
+
   # Tags only: a pull request builds the packages above and publishes nothing.
   release:
     if: startsWith(github.ref, 'refs/tags/')
-    needs: [binary, deb, rpm, arch]
+    needs: [binary, deb, rpm, arch, contents]
     runs-on: ubuntu-22.04
     timeout-minutes: 15
     permissions:

CHANGELOG.md

@@ -9,6 +9,9 @@ All notable changes to OBSBot4Linux. The format follows
 
 - The repository moved to github.com/hellwand/obsbot4linux on 2026-11-12; the old address redirects (the link change itself landed in #109).
 - README and package text now say "most settings OBSBOT Center offers" and link `docs/center-parity.md` for the gaps; they also state the glibc 2.34 floor, how to switch to the socket units while the widget's daemon runs, to restart the daemon after an upgrade (socket users: `systemctl --user restart obsbot4linux.service`; a daemon started by `watch` ends with the shell's unit), that `zoom F --speed S` and `zoom stop` leave the AI mode alone, the `device busy` window of the on-air probe on uvcvideo up to 6.16, and the order of auto and manual image controls (#121).
+- The source is a cargo workspace now: `crates/obsbot-device` holds the camera access,
+  `crates/obsbot4linux` the CLI and the daemon. The program, its output and the packages do not
+  change.
 
 ### Fixed
 

CONTRIBUTING.md

@@ -4,8 +4,8 @@ Every change goes through an issue and a pull request, also the maintainer's:
 
 1. Open an issue: what is wrong or missing, how to reproduce it, which camera and firmware.
 2. Open a pull request against `main` whose description starts with `Fixes #<issue>`.
-3. CI must be green (`cargo fmt --check`, `cargo clippy --all-targets --locked -- -D warnings`,
-   `cargo test`, and `cargo test` again with the `rust-version` from `Cargo.toml`).
+3. CI must be green (`cargo fmt --check`, `cargo clippy --workspace --all-targets --locked -- -D warnings`,
+   `cargo test --workspace`, and `cargo test --workspace` again with the `rust-version` from `Cargo.toml`).
    Changes that only touch docs (Markdown files, `LICENSE`, `docs/`) skip those four; the
    `required` check still reports. No changelog entry is enforced per pull request; the release
    tag needs its `CHANGELOG.md` section.

Cargo.toml

@@ -1,57 +1,25 @@
-[package]
-name = "obsbot4linux"
+[workspace]
+resolver = "3"
+members = ["crates/obsbot-device", "crates/obsbot4linux"]
+
+[workspace.package]
 version = "0.13.2"
 edition = "2024"
 rust-version = "1.88"
-description = "Control OBSBOT webcams on Linux from the console and the DMS widget"
 authors = ["Thomas Kroll"]
 license = "GPL-3.0-or-later"
 repository = "https://github.com/hellwand/obsbot4linux"
 homepage = "https://github.com/hellwand/obsbot4linux"
-readme = "README.md"
 publish = false
 
-[lib]
-name = "obsbot4linux"
-path = "src/lib.rs"
-
-[[bin]]
-name = "obsbot4linux"
-path = "src/main.rs"
-
-[dependencies]
+[workspace.dependencies]
+obsbot-device = { path = "crates/obsbot-device" }
 clap = { version = "4", features = ["derive"] }
 nix = { version = "0.31", features = ["fs", "ioctl"] }
 serde = { version = "1", features = ["derive"] }
 serde_json = "1"
 thiserror = "2"
+hex = "0.4"
 
 [profile.release]
 strip = true
-
-[dev-dependencies]
-hex = "0.4"
-
-[package.metadata.deb]
-maintainer = "Thomas Kroll <t.kroll@outlook.com>"
-section = "video"
-extended-description = "Most settings OBSBOT Center offers, from the console and from the DMS bar widget.\nWhat is missing: https://github.com/hellwand/obsbot4linux/blob/main/docs/center-parity.md\nThe obsbot4linux daemon (systemd user socket) owns the camera state."
-depends = "$auto"
-license-file = ["LICENSE", "0"]
-assets = [
-    ["target/release/obsbot4linux", "usr/bin/", "755"],
-    ["packaging/systemd/obsbot4linux.service", "usr/lib/systemd/user/", "644"],
-    ["packaging/systemd/obsbot4linux.socket", "usr/lib/systemd/user/", "644"],
-    ["README.md", "usr/share/doc/obsbot4linux/", "644"],
-    ["CHANGELOG.md", "usr/share/doc/obsbot4linux/", "644"],
-]
-
-[package.metadata.generate-rpm]
-assets = [
-    { source = "target/release/obsbot4linux", dest = "/usr/bin/obsbot4linux", mode = "755" },
-    { source = "packaging/systemd/obsbot4linux.service", dest = "/usr/lib/systemd/user/obsbot4linux.service", mode = "644" },
-    { source = "packaging/systemd/obsbot4linux.socket", dest = "/usr/lib/systemd/user/obsbot4linux.socket", mode = "644" },
-    { source = "README.md", dest = "/usr/share/doc/obsbot4linux/README.md", mode = "644", doc = true },
-    { source = "CHANGELOG.md", dest = "/usr/share/doc/obsbot4linux/CHANGELOG.md", mode = "644", doc = true },
-    { source = "LICENSE", dest = "/usr/share/licenses/obsbot4linux/LICENSE", mode = "644" },
-]

README.md

@@ -407,7 +407,7 @@ it does not arm the flag but consumes one that a recall or `0x6604` armed earlie
 goes Static on arrival; afterwards tracking may stay suspended, since the view's actions name no
 AI mode, as with `startup go`. Not seen so far: tracking stayed on after a `zone view go` in AI normal. The flag part is still to be confirmed.
 
-Adding a model: an entry in `MODELS` in `src/models.rs` (name, USB id, by-id and card name
+Adding a model: an entry in `MODELS` in `crates/obsbot-device/src/registry.rs` (name, USB id, by-id and card name
 patterns) makes it detected. Its commands and status decoding differ per camera and today exist
 for the Tiny 2 Lite only; the plan is one module per model behind the same commands, once a
 camera is at hand to capture and test (see [CONTRIBUTING.md](CONTRIBUTING.md)).

crates/obsbot-device/Cargo.toml

@@ -0,0 +1,21 @@
+[package]
+name = "obsbot-device"
+description = "Camera access for obsbot4linux: transport, frame codec and the camera models"
+version.workspace = true
+edition.workspace = true
+rust-version.workspace = true
+authors.workspace = true
+license.workspace = true
+repository.workspace = true
+homepage.workspace = true
+publish.workspace = true
+
+[dependencies]
+clap.workspace = true
+nix.workspace = true
+serde.workspace = true
+serde_json.workspace = true
+thiserror.workspace = true
+
+[dev-dependencies]
+hex.workspace = true

crates/obsbot-device/src/enumeration.rs

@@ -0,0 +1,118 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+// Derived from Tiny4Linux (EUPL-1.2), used under EUPL-1.2 Article 5.
+
+//! Finding a supported camera without talking to it: `/dev/v4l/by-id` links first, the V4L2
+//! card name as fallback.
+
+use crate::registry::{self, Model};
+use nix::ioctl_read;
+use std::fs::{self, File};
+use std::os::fd::AsRawFd;
+use std::path::PathBuf;
+
+const V4L2_CAP_META_CAPTURE: u32 = 0x0080_0000;
+
+#[repr(C)]
+#[derive(Default)]
+struct V4l2Capability {
+    driver: [u8; 16],
+    card: [u8; 32],
+    bus_info: [u8; 32],
+    version: u32,
+    capabilities: u32,
+    device_caps: u32,
+    reserved: [u32; 3],
+}
+
+ioctl_read!(vidioc_querycap, b'V', 0, V4l2Capability);
+
+/// A camera found by enumeration, before any command is sent to it.
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct Detected {
+    pub model: &'static Model,
+    /// The V4L2 node to stream from: the stable `/dev/v4l/by-id/...-video-index0` link when
+    /// there is one, else `/dev/videoN`.
+    pub device: PathBuf,
+}
+
+fn card_name(file: &File) -> Option<(String, u32)> {
+    let mut cap = V4l2Capability::default();
+    unsafe { vidioc_querycap(file.as_raw_fd(), &mut cap) }.ok()?;
+    let end = cap
+        .card
+        .iter()
+        .position(|b| *b == 0)
+        .unwrap_or(cap.card.len());
+    Some((
+        String::from_utf8_lossy(&cap.card[..end]).into_owned(),
+        cap.device_caps,
+    ))
+}
+
+/// Finds a supported camera without talking to it: by-id symlink first, V4L2 card name
+/// (VIDIOC_QUERYCAP, a read-only ioctl) as fallback.
+pub fn detect() -> Option<Detected> {
+    let by_id = fs::read_dir("/dev/v4l/by-id")
+        .into_iter()
+        .flatten()
+        .flatten()
+        .map(|e| e.path())
+        .collect();
+    if let Some(detected) = first_by_id(by_id) {
+        return Some(detected);
+    }
+
+    let mut paths: Vec<PathBuf> = fs::read_dir("/dev")
+        .ok()?
+        .flatten()
+        .map(|e| e.path())
+        .filter(|p| {
+            p.file_name()
+                .is_some_and(|n| n.to_string_lossy().starts_with("video"))
+        })
+        .collect();
+    paths.sort();
+    for path in paths {
+        if let Ok(file) = File::open(&path)
+            && let Some((card, caps)) = card_name(&file)
+            && caps & V4L2_CAP_META_CAPTURE == 0
+            && let Some(model) = registry::from_card(&card)
+        {
+            return Some(Detected {
+                model,
+                device: path,
+            });
+        }
+    }
+    None
+}
+
+/// The first supported camera among the by-id links, sorted: `read_dir` order is unspecified,
+/// so with two cameras the controlled one could change between runs.
+fn first_by_id(mut links: Vec<PathBuf>) -> Option<Detected> {
+    links.sort();
+    links.into_iter().find_map(|device| {
+        let model = registry::from_by_id(&device.file_name()?.to_string_lossy())?;
+        Some(Detected { model, device })
+    })
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn by_id_detection_does_not_depend_on_directory_order() {
+        let link = |serial: &str| {
+            PathBuf::from(format!(
+                "/dev/v4l/by-id/usb-Remo_Tech_Co.__Ltd._OBSBOT_Tiny_2_Lite_{serial}-video-index0"
+            ))
+        };
+        let other = PathBuf::from("/dev/v4l/by-id/usb-Logitech_BRIO-video-index0");
+        let picked = first_by_id(vec![other.clone(), link("B"), link("A")]).unwrap();
+        assert_eq!(picked.device, link("A"));
+        let picked = first_by_id(vec![link("A"), link("B"), other]).unwrap();
+        assert_eq!(picked.device, link("A"));
+        assert_eq!(first_by_id(Vec::new()), None);
+    }
+}