Re: [rtcweb] Proposed Plan for Usage of SDP and RTP - Lower level API minus SDP

"Timothy B. Terriberry" <tterriberry@mozilla.com> Fri, 08 March 2013 03:05 UTC

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Subject: Re: [rtcweb] Proposed Plan for Usage of SDP and RTP - Lower level API minus SDP
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Silvia Pfeiffer wrote:
> Is there any way for the Web developer to influence the negotiation of,
> say, the video resolution? For example, if the video is displayed in a
> 160x120 video element, then it makes no sense to receive anything larger
> than that resolution. I was under the impression that this would have to
> be done through manipulating SDP?

Again, that would be done via constraints:
http://tools.ietf.org/html/draft-alvestrand-constraints-resolution-00#section-4

See Section 3.1 for examples involving gUM... the draft doesn't have any 
examples, but these same constraints could be applied to incoming 
streams using the settings API currently under discussion in the W3C. 
It's perhaps an open question whether or not a <video> tag should 
propagate back such constraints in the absence of any explicitly set 
ones... but that's a question for the W3C.