A containerized service that watches a source folder and automatically transcodes audio files to multiple formats simultaneously.
Keep one library in several formats: lossless for the archive, lossy for phones and cars. Drop a FLAC into the source folder and the ALAC, MP3, AAC and Opus copies appear in their own trees.
- Watches the source folder and reacts to new, changed, renamed and deleted files.
- Writes any number of outputs in one pass, in ALAC, AAC, MP3, Opus, FLAC or WAV at the bitrate you pick.
- Mirrors the Artist/Album folder tree in every output.
- Copies lossy sources (MP3, M4A, Ogg, Opus, WMA) unchanged instead of inflating them into a lossless output.
- Fails loudly on a source that does not decode cleanly, and writes no output for it.
- Keeps ReplayGain, MusicBrainz ids, ISRC, label and sort tags in ALAC and AAC copies.
- Fetches synced
.lrclyrics, and writes nothing when no real lyrics are found. - Embeds cover art if you want it.
- Writes atomically and removes orphaned outputs, but never deletes anything when a folder looks empty.
- Handles Unicode file names.
- Ships as a small container on Python 3.14-slim with FFmpeg.
curl -fsSL -o config.yaml https://raw.githubusercontent.com/GeiserX/audio-transcode-watcher/main/config.example.yaml
docker run -d --name audio_transcoder -e CONFIG_FILE=/app/config.yaml \
-v ./config.yaml:/app/config.yaml:ro -v /path/to/flac:/music/flac:ro -v /path/to/mp3:/music/mp3 \
drumsergio/audio-transcoder:0.6.1Edit config.yaml first so its outputs match the folders you mount; the example writes ALAC, MP3 and AAC. Getting started has Docker Compose and the full docker run.
- Getting started: Docker Compose and Docker CLI
- Configuration: the full YAML example, supported codecs,
CONFIG_JSON - Usage: what happens once it runs, and the verification tool
- How it works: sync and watch mode, folder mirroring, safety guards, performance
- Development: tests, building the image, contributing
- Roadmap
- Changelog
| Project | Description |
|---|---|
| slskd-transform | Bulk upgrade your music library from lossy to lossless via Soulseek |
| telegram-slskd-local-bot | Automated music discovery and download via Telegram |
| quality-gate-encoder (formerly jellyfin-encoder) | Automatic 720p HEVC, H.264 or AV1 copies for Jellyfin |