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Re: Releasing media stream created by gUM

From: Harald Alvestrand <harald@alvestrand.no>
Date: Mon, 21 Oct 2013 21:08:47 +0200
Message-ID: <52657BBF.1080003@alvestrand.no>
To: Kevin Dempsey <kevindempsey70@gmail.com>, public-media-capture@w3.org
On 10/18/2013 10:50 AM, Kevin Dempsey wrote:
> In earlier versions of the gUM spec, the stream created by a 
> getUserMedia() call had a stop() method that ended all the tracks, 
> reduced the reference count on the track sources and if that reference 
> count reached zero, the source was stopped (and recommended that any 
> 'on-air' indicator was removed).
>
> In recent versions of the spec the stream doesn't have a stop() 
> method, but MediaStreamTrack does. However, this stop() method stops 
> the source regardless of whether any other track is using that source. 
> I know that the 'best practices' section recommends that sources 
> should not be shared but the MediaStreamTrack stop() function's "kill 
> switch" behaviour forces that upon implementors.
>
> So under the current spec, the release the stream created by 
> getUserMedia() you have to call stop on all tracks it has (one audio 
> and one video maximum). This will also kill the sources and therefore 
> end any track also using those sources.
>
> Can we also have the earlier behaviour in a function on the returned 
> stream (perhaps not called stop() to reduce possible confusion)?
>
Possibly the closest equivalent to the old behaviour is to call 
MediaStream.removeTrack() for all the tracks. We don't have a reference 
counter that can be counted down yet, but when all references to the 
tracks that take input from a source are lost, we would expect the 
source to stop.
Received on Monday, 21 October 2013 19:09:11 UTC

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