Playlist Sync (foo_playlist_sync)

One-way sync of foobar2000 playlists to a folder, USB stick or memory card, with a detailed report of every file that was added, replaced, removed or skipped.

A modern replacement for the abandoned 32-bit foo_ows (One Way Sync). Works with foobar2000 2.x, both 64-bit and 32-bit.

Install

Download foo_playlist_sync-<version>.fb2k-component and double-click it, or use Preferences › Components › Install…. Then restart foobar2000.

Use

1. Preferences › Tools › Playlist Sync: choose the destination folder, tick the playlists to sync, and adjust the options.
2. Click Preview… to see what would happen without changing anything. From the preview report you can click Sync now to go ahead.
3. Later syncs are available from File › Playlist Sync › Sync now / Preview sync. You can also put them on a toolbar button or a keyboard shortcut.

Settings

Setting	What it does
Destination	Where files are copied: a drive letter (E:\), a folder, a network share, or an MTP device (phone or player without a drive letter) as mtp://Device/Storage/Folder. Browse ▾ lists the connected MTP devices.
File name pattern	Title formatting for the path below the destination. The file extension is added automatically. Characters that aren't allowed in file names are replaced. A folder or file name that starts with a dot gets _ instead, because Android hides dot folders. The default gives Album Artist\Album (Date)\NN - Title.ext; a simpler choice is $if2(%album artist%,Unknown Artist)\$if2(%album%,Unknown Album)\%filename%
When the file already exists on the destination:
Replace if size or date differs	Copies again when the source file changed since the last sync.
Replace only if tags differ	Copies again only when tags changed. A file whose date changed but whose tags are the same is skipped. ReplayGain is never compared. Ignore tags lists more fields to leave out (separate with ;, * is a wildcard).
↳ Also replace re-encoded files	Also copies again when codec, bitrate, sample rate, channels or exact length changed. Use it to pick up re-encodes that kept the same tags.
Never replace	A file at the same path and name always counts as identical.
Keep original created and modified dates	Copied files get the source file's timestamps. When off, they get the time of the copy.
Remove files that are no longer in the playlists	Deletes destination files that the selected playlists no longer contain. Empty folders are removed too.
↳ Only files copied by Playlist Sync	(Default, safer.) Only removes files that an earlier sync copied. When off, every other file in the destination folder is removed.
Album art: Copy cover to each album folder	Puts one cover image into every album folder on the destination. Find lists image names to look for next to the album's tracks, in priority order (default folder; front; cover, as .jpg/.jpeg/.png). Else use embedded cover falls back to the front cover embedded in the first track. Save as is the name on the destination (default folder); the image type is kept. Covers are compared, replaced and removed like tracks.
Create .nomedia file in the destination folder	Puts an empty .nomedia file in the destination folder. Android media scanners then skip the folder and everything below it. Note that apps relying on Android's media library won't see the music either; folder-based players still do. Playlist Sync never removes this file.
Write .m3u8 playlist files	Writes one UTF-8 playlist per synced playlist, with paths relative to the playlist file. Linux-style uses / and LF line endings for players that need them.

How it decides

• Each run compares every track of the selected playlists with the destination. A file that appears in several playlists, or several subsongs of one file, is copied once.
• A small hidden state file, .playlist_sync, in the destination folder remembers what was copied: source size and date, plus fingerprints of the tags and technical info. Because of this, "tags only" comparison is instant, and dates don't have to match exactly (FAT32 has 2-second timestamps and DST shifts). If the state file is missing (for example, a device you filled by hand), Playlist Sync reads the tags from the files on the destination once, and from then on uses the state file.
• Safety:
  • Copies go to a temporary *.psync-tmp file first and replace the old file only when complete. Pulling the cable mid-copy never leaves a half-written file under the real name.
  • Free space is checked before anything is changed.
  • A source file that is temporarily missing (for example, an unplugged library drive) never causes its copy to be deleted. The same goes for album covers.
  • With Remove files on, a destination folder that contains the source files is refused.
  • If none of the playlists' files could be synced, nothing is deleted.
• Files are removed first, to make room, and copied afterwards. Cancelling keeps everything consistent: the report lists what was done before you cancelled.

Report

After every run a report window lists all actions. You can filter by Added / Replaced / Removed / Skipped / Errors / Playlists, and sort by any column. Double-click an entry to show the file in Explorer. Export… saves the report as .txt or .csv. With Save a log of each sync on (the default), every run is also saved to <foobar2000 profile>\playlist_sync_logs\; the newest 100 logs are kept. Turning it off only stops the log files; the report window still appears after every run.

MTP devices (phones)

Connect the phone, unlock it and choose File transfer (USB mode). Then pick it under Browse ▾. The destination defaults to the storage's Music folder; you can edit the path.

Differences from drive-letter destinations:

• Phones usually ignore file dates sent over MTP. Decisions therefore rely on the sync state file, and Keep original dates is a best-effort request to the device.
• There's no in-place tag reading over MTP. When a device has no sync state file yet (for example, you filled it by hand), files are compared by size once; after the first sync the state file is used.
• A replaced file is first uploaded under a temporary name. Only then is the old copy deleted and the new one renamed. On devices that don't allow renaming, the old copy is deleted first.
• Transfers are slower than USB mass storage. Large first syncs take a while; later syncs only copy what changed.

Not supported yet

• Tracks from external .cue sheets (embedded cue sheets work)
• Several sync profiles (different devices with different settings)
• Transcoding (intentionally left out)

Build

Requirements: Visual Studio 2022 with Desktop development with C++, plus the C++ ATL and C++ MFC components and a Windows SDK. The foobar2000 SDK (2026-10-01) and WTL 10 headers are vendored in sdk/ and third_party/wtl/.

scripts\build.ps1          # x86 + x64 Release, runs tests, writes dist\*.fb2k-component
scripts\install-test.ps1   # copies the x64 build into a portable foobar2000 (close it first)

Layout:

• src/sync_core.*: the sync engine. It has no foobar2000 dependency and is unit-tested by tests/core_tests.cpp.
• src/dest_fs.h: the destination filesystem layer. dest_local.cpp handles folders and drives; dest_mtp.cpp handles MTP via Windows Portable Devices.
• core_tests --mtp lists the WPD devices; core_tests --mtp-selftest mtp://Device/Storage/EmptyFolder runs a write test on real hardware and cleans up afterwards.
• src/sync_task.cpp: collects tracks from playlists, computes the tag fingerprints and runs the engine in a background thread.
• src/preferences.cpp, src/report_dialog.cpp, src/mainmenu.cpp: the UI.