Re: [rtcweb] 答复: Mute implementations (Re: More Comments ondraft-ietf-rtcweb-use-cases-and-requirements-07)

Randell Jesup <randell-ietf@jesup.org> Sun, 17 June 2012 07:47 UTC

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Subject: Re: [rtcweb] 答复: Mute implementations (Re: More Comments ondraft-ietf-rtcweb-use-cases-and-requirements-07)
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On 6/17/2012 2:48 AM, Sunyang (Eric) wrote:
> You said:  "MediaStreams need to be able to be repointed, switched, processed, etc, OR you need to be able to replace a MediaStream in the inputs to PeerConnection with another one transparently without renegotiation (and that misses a bunch of uses)."
>
> But if the MediaStream  you choose to replace the existing one contain codecs that not supported by remote end, I think we still need renegotiation.
> Or you can make sure that the browser can choose the same codecs as default with the replaced one, I think browser can not do this.

It's possible that renegotiation might be required in *some* cases with
pre-encoded data from the camera, but not many (if any), since we need
to rate-control the data. We would need to decode the camera stream
(H.264 typically), then re-encode at the correct bitrate. Or we'll need
to change the camera bitrate targets on a frame-by-frame basis (unlikely).

-- 
Randell Jesup
randell-ietf@jesup.org