Bug 172831 – A cloned MediaStreamTrack should mute independently other tracks using the same source

• Component: Media
• Status: RESOLVED FIXED

[Prerak Jain]

MediaStreamTrack clone API just clones the track but not the media source, as a result, if a track is muted/stopped it will mute/stop the media source and all the tracks associated with media source will be affected. A change in state of a track using a media source should not impact the other tracks using the same media source.

[Radar WebKit Bug Importer]

<rdar://problem/32518527>

[youenn fablet]

(In reply to Prerak Jain from comment #0)
> MediaStreamTrack clone API just clones the track but not the media source,
> as a result, if a track is muted/stopped it will mute/stop the media source
> and all the tracks associated with media source will be affected. A change
> in state of a track using a media source should not impact the other tracks
> using the same media source.

There are things that can be done in terms of stopping/muting.
If it comes to properties of the source (width, height, echo cancellation...), that may be harder.

[youenn fablet]

Created attachment 313153 [details]
Patch

[youenn fablet]

Created attachment 313154 [details]
Patch

[Eric Carlson]

Comment on attachment 313153 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=313153&action=review

> Source/WebCore/ChangeLog:11
> +        Moving enabled handling in MediaStreamTrackPrivate instead of RealtimeMediaSource.

Nit: "Moving enabled handling in" => "Move enabled handling to"

> Source/WebCore/ChangeLog:13
> +        Moving WebRTC and WebAudio customers of RealtimeMediaSource to MediaStreamTrackPrivate.
> +        Moving creation of WebAudio provider to MediaStreamTrackPrivate.

Nit: "Moving" => "Move"

> Source/WebCore/platform/mediastream/MediaStreamTrackPrivate.cpp:196
>      mediaSample.setTrackID(id());

This isn't new to this patch, but sample can only have one "track ID" so I think we have a problem when a source is attached to more than one track.

[youenn fablet]

> > Source/WebCore/platform/mediastream/MediaStreamTrackPrivate.cpp:196
> >      mediaSample.setTrackID(id());
> 
> This isn't new to this patch, but sample can only have one "track ID" so I
> think we have a problem when a source is attached to more than one track.

I was wondering what was its actual use.
It seems it is only used in SourceBuffer::sourceBufferPrivateDidReceiveSample.
Maybe trackID should not be set in MediaSample but retrieved from the track or from another parameter.

[youenn fablet]

Created attachment 313159 [details]
Fixes build

[youenn fablet]

Created attachment 313164 [details]
Fixing build again

[WebKit Commit Bot]

Comment on attachment 313164 [details]
Fixing build again

Clearing flags on attachment: 313164

Committed r218497: <http://trac.webkit.org/changeset/218497>

[WebKit Commit Bot]

All reviewed patches have been landed.  Closing bug.

[youenn fablet]

*** Bug 174126 has been marked as a duplicate of this bug. ***