Boomarr

🔊 Symlink-based audio language filter for Plex, Jellyfin & Emby — automatically mirrors your media library, keeping only files with your desired audio tracks.

What is this?

Your library has German, English and French releases mixed together, but some people in your household only want to see what they can actually watch in their language. Boomarr scans your library with ffprobe and builds separate folders that contain only (symlinks to) the files with the audio languages you choose. Point a Plex/Jellyfin/Emby library at such a folder and share it with whoever needs it.

/data/media/movies                     /data/filtered/movies-deu
├── Film A (2020)/Film A.mkv  deu,eng  ├── Film A (2020)/Film A.mkv  -> …
├── Film B (2021)/Film B.mkv  eng      ├── Film C (2022)/Film C.mkv  -> …
└── Film C (2022)/Film C.mkv  ger      └── Film C (2022)/Film C.de.srt -> …
    └── Film C.de.srt

No files are copied, moved or modified, and no disk space is used.

Features

• Any number of filtered libraries per source, e.g. German-only, English-only and "German and English" side by side.
• Smart language matching: ger, deu, de and de-DE are the same language; aliases (e.g. und for untagged tracks); any / all modes.
• Fast: every file is probed only once (SQLite probe cache, parallel probing); later scans only look at new or changed files.
• Always correct: every scan reconciles the output with the current config, so config changes, new libraries and deleted links are handled automatically.
• Safe by design: sources must be read-only, only Boomarr's own symlinks are ever removed, and an unmounted share never empties your filtered library. Details.
• Subtitles included: external subtitles (Film.de.srt) follow their media file.
• More than languages: combine with resolution (4K only), video/audio codec, surround channels, or invert any filter.
• Sonarr/Radarr aware: optionally reuse the languages they already know instead of probing, and rescan instantly on their webhooks.
• Integrates with your stack: Prometheus /metrics, Apprise notifications (Telegram, Discord, ntfy, …), automatic Plex/Jellyfin/Emby folder refresh after changes, and a removal guard against accidental mass deletions.
• Homelab friendly: multi-arch Docker image (amd64/arm64) with PUID/PGID or rootless operation, healthcheck, Helm chart, Unraid template, systemd unit, --dry-run.

Quick start

# docker-compose.yml
services:
  boomarr:
    image: ghcr.io/eulemitkeule/boomarr:latest
    container_name: boomarr
    restart: unless-stopped
    environment:
      PUID: 1000
      PGID: 1000
      TZ: Europe/Berlin
    volumes:
      - ./config:/config
      - /srv/data/media:/data/media:ro          # read-only!
      - /srv/data/filtered:/data/filtered

# config/boomarr.yml
output_path: /data/filtered

triggers:
  - type: schedule
    interval: 600

libraries:
  - name: Movies
    input_path: /data/media/movies
    symlink_libraries:
      - filters:
          - type: audio_language
            languages: [deu]            # -> /data/filtered/movies-deu

  - name: Shows
    input_path: /data/media/shows
    symlink_libraries:
      - name: Serien (Deutsch)          # -> /data/filtered/Serien (Deutsch)
        filters:
          - type: audio_language
            languages: [deu]

docker compose run --rm boomarr boomarr scan --dry-run   # preview
docker compose up -d

Documentation

Commands

boomarr watch               run continuously (Docker default)
boomarr scan [--dry-run] [--force]   one full scan (--force: bypass removal guard)
boomarr clean               remove broken symlinks only
boomarr status [--json]     cache statistics, languages found, output folders
boomarr healthcheck         liveness check for Docker/Kubernetes
boomarr paths               print writable directories
boomarr version

Alternatives

Development

uv sync --all-groups
uv run pytest                       # needs ffprobe for the integration test
uv run ruff check . && uv run ruff format --check . && uv run ty check
docker compose -f docker-compose.dev.yml up --build

See CONTRIBUTING.md. Test media can be regenerated with uv run python tests/fixtures/generate.py.

Inspiration

Inspired by Filip Rojek's blog post on creating a language-specific Jellyfin library with a Bash script. Boomarr turns that idea into a configurable, safe and Docker-native tool.

License

MIT