Adding video/audio tracks to html video element

[Lukasz Jagielski]

Hi,

I would like to ask for some clarification regarding the param 'id' of WebMediaPlayerClient::addVideoTrack.

I'm getting a DCHECK in VideoTrackList::trackSelected if I create two video tracks with

the same id and try to change current video track during playback. So my question is if

this is required that id's if video/audio tracks are unique and this DCHECK is expected?

Spec here takes into account situations with multiple tracks with the same id:  https://html.spec.whatwg.org/#dom-videotracklist-gettrackbyid

Thanks,

Łukasz

[Mounir Lamouri]

+avayvod@ +servolk@ who might be familiar with this.

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[Sergey Volk]

Hmm, the git blame for that DCHECK isn't really useful due to pointing to some blink reformat change, but I think it was there for a long time and looking at surrounding code it was most likely added by phi...@opera.com.

It looks like the spec indeed doesn't explicitly prohibit having media tracks with the same ids, but I'm not sure if it could be really useful anywhere. Chromium/Chrome media stack has a separate set of media track objects and we are currently using track ids to map blink tracks to Chromium media tracks. Perhaps the spec needs to be clarified?

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