MetaMesh Plugin: Language

A MetaMesh container plugin that adds a media file's audio-track languages to the languages/<lang3> key-set (METADATA_KEYS.md §9).

What it does

After the ffmpeg plugin has stored the stream table, this plugin:

• reads the per-stream table in either shape: the nested stream collection meta-sort's /process payload carries (array of JSON strings, array of objects, JSON string, or index-keyed object) or meta-core's flat stream/{n} keys;
• keeps audio streams only (subtitle-track languages belong to subtitleLanguages/*);
• normalises each code onto ISO 639-2/B alpha-3 — fr/fra → fre, de/deu → ger, pt-BR → por — the vocabulary the languages: query filter and meta-watch compare against;
• adds languages/<code> = "true" for each new member in one merge (PATCH).

It never writes und (or zxx/mis), never writes titles/*, never deletes or overwrites any other key, and a re-run over an already-tagged record writes nothing. A rejected write fails the task.

Metadata Fields

Field	Description
languages/{lang3}	Key-set member per audio-track language ("true")

Dependencies

• Requires the ffmpeg plugin to run first (it writes stream/{n}).

Configuration

No configuration required.

API Endpoints

Endpoint	Method	Description
/health	GET	Health check
/manifest	GET	Plugin manifest
/configure	POST	Update configuration
/process	POST	Process a file

Tests

pnpm test        # vitest, no network
./test.sh        # same, inside Docker

Docker

docker build -t metamesh-plugin-language .
docker run -p 8080:8080 metamesh-plugin-language

Environment Variables

Variable	Default	Description
PORT	8080	HTTP server port

License

MIT