Music Downcoder

A TypeScript CLI and web UI that scans music folders and generates bash scripts with ffmpeg commands to transcode your music library. Supports multiple encoders (mp3, ogg, ALAC copy) and parallel execution.

Published as @emgeebee/music_downcoder on npm.

Quick start (npx)

# Interactive CLI (uses built-in defaults)
npx @emgeebee/music_downcoder

# Web UI on port 3798
npx @emgeebee/music_downcoder serve -c /path/to/conf.json -H 0.0.0.0 -p 3798

Open http://localhost:3798 to pick source folder, encoders, and artist filter. After scripts are generated under cmd/, the UI lists them and lets you run individually or all at once.

Configuration

All paths and encoder settings live in a JSON config file. See docker/conf.json for a Synology/Docker example:

• ffmpeg — path to ffmpeg binary
• startFolders — source library folders shown in the UI/CLI
• encoders — output folders and formats (mp3, ogg, cp)
• commandsFolder, queueFolder, metaFile — working directories
• numOfCores, rate, autoConfirm

npx @emgeebee/music_downcoder -c ./docker/conf.json

Synology / Docker

See docker/synology-compose.yml. Copy docker/conf.json to your NAS config volume and adjust paths. The container runs:

npx @emgeebee/music_downcoder serve -H 0.0.0.0 -p 3798 -c /data/config/conf.json

Development

npm install
npm start                    # CLI
npm run serve -- -c docker/conf.json -p 3798   # web UI
npm run build

npm publish

Pushes to npm on merge to main/master via .github/workflows/publish.yml. Add an NPM_TOKEN secret to the repository (npm automation token with publish access to @emgeebee).

How it works

1. Walk the selected music directory
2. Extract/cache metadata (artist, album, genre, year) via ffmpeg
3. Generate ffmpeg/rsync commands per encoder
4. Write scripts to cmd/{core}/
5. Optionally execute via CLI or web UI