- From: Harald Alvestrand <harald@alvestrand.no>
- Date: Fri, 09 Dec 2011 13:02:19 +0100
- To: "public-webrtc@w3.org" <public-webrtc@w3.org>
- Message-ID: <4EE1F8CB.2000305@alvestrand.no>
Resurrecting this thread from last month: On 11/08/2011 01:15 AM, Harald Alvestrand wrote: > Discharging a task taken on at the TPAC meeting, some possible words > on what a media stream, a media stream track or a channel is.... > > This is based on the introduction section in section 3.1 of the > current API editors' draft. > > The|MediaStream > <http://dev.w3.org/2011/webrtc/editor/webrtc.html#mediastream>|interface > is used to represent streams of media data, typically (but not > necessarily) of audio and/or video content, e.g. from a local camera > or a remote site. The data from a|MediaStream > <http://dev.w3.org/2011/webrtc/editor/webrtc.html#mediastream>|object > does not necessarily have a canonical binary form; for example, it > could just be "the video currently coming from the user's video > camera". This allows user agents to manipulate media streams in > whatever fashion is most suitable on the user's platform. > > Each|MediaStream > <http://dev.w3.org/2011/webrtc/editor/webrtc.html#mediastream>|object > can represent zero or more tracks, in particular audio and video > tracks. Tracks can contain multiple channels of parallel data; for > example a single audio track could have nine channels of audio data to > represent a 7.2 surround sound audio track. > > <new text below> > > All tracks in a MediaStream are presumed to be synchronized at some > level. Different MediaStreams may or may not be synchronized. > > Each track in a|MediaStream > <http://dev.w3.org/2011/webrtc/editor/webrtc.html#mediastream>|object > has a corresponding|MediaStreamTrack > <http://dev.w3.org/2011/webrtc/editor/webrtc.html#mediastreamtrack>|object. > > A MediaStreamTrack represents content comprising one or more channels, > where the channels have a defined well known relationship to each > other (such as a stereo or 5.1 audio signal), and may be encoded > together for transmission as, for instance, an RTP payload type. One > MediaStreamTrack sent to another peer MUST appear as one and only one > MediaStreamTrack to the recipient. > > A channel is the smallest unit considered in this API specification. > > <end new text> > I made a couple of text changes to make it clearer following the discussion (represented by -> in, added text saying that one track @sender = one track @recipient). At this stage, I'd like to ask our editors to incorporate this text. It seems "right enough". Harald
Received on Friday, 9 December 2011 12:03:02 UTC