Text Track Data

Q: How do we pass text track data (captions, subtitles) in to the menus and other elements that need it?

Assumptions:

• At the the UI (chrome) level we are not overlaying the captions on the media, that’s the job of the media element
• We may still want access to the text track cues, to display outside of the player or do something interesting based on a metadata track.

Important text track details:

• srclang is required when kind is set
• label is not required
• “A media element cannot have more than one track with the same kind, srclang, and label.”
• Tracks can be disabled, hidden (still active and usable), and showing
• Multiple tracks of the same kind can be showing

Proposal

Available tracks list:

• One attr per ‘kind’ of track (Menus can choose to combine the lists if desired)

<media-ui-el media-captions-list="..." media-subtitles-list="..." >

• Comma-separated list with URL-encoded optional label value

<media-ui-el media-captions-list="en-US:English en:English%20%28with%20descriptions%29">

Min required
<media-ui-el media-captions-list="en">

Selected track(s)

<media-ui-el media-captions-showing="en-US es">

[heff]

@cjpillsbury it feels like we can close this one, yeah? I think we’ve implemented the major concepts, and even worked towards a solution to the last note on adjusting the captions location, via the middle chrome section.

[cjpillsbury]

Closing. Data relationship implemented. Alternate render target for captions/subtitles. should be treated as a separate issue/feature discussion if/when we try to support it.