Request to expose audio track role

[forbesjo]

This is a enhancement request for exposing an audio track's role in order to differentiate between a main English track and commentary (or any other role type that can share a language).

[ismena]

I think we can do that! Let me tentatively schedule it for 2.2 (tentatively in case our project visionaries don't approve :)).

Please note, that we don't have separate audio/video tracks anymore. Instead we have variant tracks which represent audio+video combinations. (This was introduced in 2.1 release which just went out).

[forbesjo]

Yep, I've taken that into account in the Shaka/dash.js compatible video.js plugin I'm working on

[tdaines]

+1 for this. Will getAudioLanguages() and setAudioLanguage() also be modified so that an English commentary track can be selected when the main track is English as well?

[joeyparrish]

I don't see why not. We'll do that, as well.

[tdaines]

Great thanks. If you prefer that to be in a separate issue I'm happy to make a new one.

[joeyparrish]

No, I think we can do that here.

[tdaines]

@joeyparrish How do see audio track role coexisting with the label attribute being added by PR #811?

[joeyparrish]

There can only be one label (one label attribute in DASH, one NAME attribute in HLS). There can be multiple roles in DASH, so the exposed role information will be an array.

Both accomplish similar goals. Whichever is used by your content/encoder, we will expose the information so that your application can use it to make decisions.

[joeyparrish]

The first part of this fix has been cherry-picked to v2.1.3.