- From: Stefan Håkansson LK <stefan.lk.hakansson@ericsson.com>
- Date: Fri, 23 Sep 2011 09:40:15 +0200
- To: public-webrtc@w3.org
On 2011-09-22 22:51, Timothy B. Terriberry wrote: > Harald Alvestrand wrote: >> I concluded from that discussion that we can say that all tracks in a >> MediaStream share a CNAME, but we can't say that all tracks with the >> same CNAME go to the same MediaStream. > > So what happens when a stream is added, with the same CNAME as a set of > existing streams? The current API has callbacks for adding/removing > MediaStreams, but not individual tracks within a MediaStream. > I think we need to separate things that is observable in the API and what happens at the SDP/RTP level. IMO, each MediaStream should have an identifier so that it can be referenced when transmitted over a PeerConnection. The current API draft has the "label" attribute for this purpose. So the web app developer works with MediaStreams. CNAME, SSRC, RTCP, ... is to me tools used in the transport over a PeerConnection to make sure that what should be in sync is in sync and so on - nothing the web developer should know or care about. In addition they will probably be used, perhaps in combination with something additional, to convey the label attribute of the MediaStream in some way. There may be situations when one track is part of two or more MediaStreams that are sent over the same PeerConnection. A natural optimization would be that that track is on an RTP level actually only sent once (i.e. only one RTP stream), but this is not visible to the web app. Stefan
Received on Friday, 23 September 2011 07:40:51 UTC