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Re: [mediacapture-main] Track changes on cloned streams

From: None via GitHub <sysbot+gh@w3.org>
Date: Wed, 11 Nov 2015 15:59:45 +0000
To: public-media-capture-logs@w3.org
Message-ID: <issue_comment.created-155826208-1447257581-sysbot+gh@w3.org>
@alvestrand I think you're missing [this 
line](http://w3c.github.io/mediacapture-main/getusermedia.html#mediastreamtrackevent):

"The addtrack and removetrack events notify the script that the track 
set of a MediaStream has been updated by the User Agent."

AFAICT this gives browsers the ability to add and remove tracks to any
 stream at any time for any reason. This impedance mismatch exists to 
support host-managed streams in other specs. Other specs need to solve
 what happens to streams and stream-clones in these cases, and need 
guidance. For instance:

In [WebRTC](http://w3c.github.io/webrtc-pc/#events-on-mediastream) 
what should happen to stream-clones when I do this mid-call:

    pc.removeTrack(stream.getTracks()[0]); pc.addTrack(someNewTrack, 
stream); // +renegotiate

In 
[mediacapture-fromelement](https://w3c.github.io/mediacapture-fromelement/index.html),
 common things like looping and source manipulation cause tracks to 
get swapped out of the stream.

-- 
GitHub Notif of comment by jan-ivar
See 
https://github.com/w3c/mediacapture-main/issues/271#issuecomment-155826208
Received on Wednesday, 11 November 2015 15:59:47 UTC

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