How to identify tracks after creating a new MS

Hi,

I'm looking at the MediaStream constructor in the "Media Capture and 
Streams" document [1].

If you use it like:

var newStream = new MediaStream([track_a, track_b, track_c]);

my understanding is that newStream would consist of three _new_ 
MediaStreamTracks that represent the same sources as track_a, track_b 
and track_c; we can call them track_x, track_y and track_z.

My problem is now, how would I correlate? Say I know that track_a is the 
room camera, track_b the speaker camera, and track_c a video of the 
slides; but what about _x, _y and _z?

The id attribute can't be used, since it is unique for each track. The 
kind attribute is video for all of them. The label may not be sufficient 
(it could say "USB camera makeX" or something for all three tracks).

I guess what I end up in is another reason why we need the "sourceId" 
that is proposed in [2].

Stefan

[1] http://dev.w3.org/2011/webrtc/editor/getusermedia.html
[2] 
https://dvcs.w3.org/hg/dap/raw-file/tip/media-stream-capture/proposals/SettingsAPI_proposal_v6.html

Received on Thursday, 21 February 2013 10:33:52 UTC