Player does not show LANGUAGE but uses NAME tag for subtitle and audio selection.

[matvp91]

Describe the bug We don't take LANGUAGE into account for EXT-X-MEDIA tags. Run this playlist, https://storage.googleapis.com/shaka-demo-assets/angel-one-hls/hls.m3u8, in the player and you'll notice that the names of the audio tracks in player are not correct.

Expected behavior Use LANGUAGE as the primary label for audio tracks, and fallback to NAME.

Additional context Today we simply take NAME, lowercase it, uppercase the first character and use that as the label. While this works for assets that are produced with Mixwave (eg; the NAME is set as uppercase language by the packager), this will fail when we play playlists from elsewhere.

See EXT-X-MEDIA - LANGUAGE in the HLS spec: https://datatracker.ietf.org/doc/html/draft-pantos-hls-rfc8216bis

Extra

• The lexical parser does not map LANGUAGE.
• The parser does not take the language attribute into account, it doesn't exist on the Media type.
• When we stringify a MediaPlaylist, let's add the LANGUAGE tag to EXT-X-MEDIA. This'll be the next logical step after we implemented this feature in the (lexical) parser.
• The player should use the language tag provided by the underlying HLS.js instance. We should also not lowercase the name / capitalize the first letter, as this is too specific for assets that are not produced by Mixwave. We did this because we wanted to have a textual representation of a track but this'll no longer be needed since we're going to rely on LANGUAGE.
• Fallback to NAME as-is, since LANGUAGE is defined optional in the spec.
• I'm not too sure about this, but I think the packager does NOT populate the LANGUAGE tag. We should look into this, since the source (meta.json file) does contain a notion of which language is for which track.

[hot-cacao]

Can I have this issue?

[matvp91]

Sure! Have fun.

[matvp91]

Added in https://github.com/matvp91/mixwave/commit/e4a5cd952062a6ebf1e740bf4e07ea2c06dbc245