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Re: Can getUserMedia return multiple mediastreams?

From: Stefan Hakansson LK <stefan.lk.hakansson@ericsson.com>
Date: Fri, 1 Jun 2012 14:25:34 +0200
Message-ID: <4FC8B4BE.5040707@ericsson.com>
To: public-media-capture@w3.org
I think it is not yet fully specified how many video tracks the stream
generated by getUserMedia can contain, and this has been discussed a bit.

However, there is always the possibility to create a new MediaStream,
containing all the video tracks you want, from tracks in existing
MediaStream's.

Stefan

On 06/01/2012 04:31 AM, Sunyang (Eric) wrote:
> now there is navigator.getUserMedia() function for html5
> 
> But JavaScript can only return 1 stream returned by getUserMedia can capture
> 
> the stream by successCallback.
> 
> For example:
> 
> getUserMedia({video:true},successCallback,errorCallback)
> 
> function successCallback(stream)
> 
> {
> 
> video.src = URL.createObjectURL(stream)
> 
> }
> 
> Now when we develop some face detection feature using html5, we have 2 
> or more
> 
> camera connect to browser, but only by browser UI can we choose which 
> one camera
> 
> can we use. We can not let JS to choose which camera can use, or use all 
> the cameras
> 
> at the same time to manipulate the camera chosen for face detection.
> 
> So, can we in future media capture draft let getUserMedia return 
> references for all available
> 
> cameras connect to browser in a array, so we can iterate streams and let 
> JS to
> 
> choose the one we want for later processing, Or in some 3D scenario, to
> 
> manipulate multiple streams from cameras to show some 3D scene. for 
> example a
> 
> better quality camera for face detection.
> 
> And streams Array returned by getUserMedia can contain quality 
> information (1
> 
> standard for 1 mega-pixel, 5 standard for mega-pixel )or optionally the
> 
> description of the camera, so JS can choose by filtering or comparision.
> 
> For example:
> 
> getUserMedia({video:true},successCallback,errorCallback)
> 
> function successCallback(MediaStreamList or MediaStream[] type etc)
> 
> {
> 
> while(i<MediStreamList.length)
> 
> {
> 
> if MediaStreamList(i).quality>5
> 
> video.src=url.createObjectURL(MediaStreamList(i))
> 
> break;
> 
> ......
> 
> }
> 
> }
> 
> Thanks a lot
> 
> Expecting for feedback.
> 
> ------------------------------------------------------------------------
> 
> 孙扬
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Received on Friday, 1 June 2012 13:11:55 UTC

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