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Re: [rtcweb] On video codec for rtcweb

Roman Shpount <roman@telurix.com> Fri, 23 March 2012 16:48 UTC

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Date: Fri, 23 Mar 2012 12:48:30 -0400
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From: Roman Shpount <roman@telurix.com>
To: "Timothy B. Terriberry" <tterriberry@mozilla.com>
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Cc: rtcweb@ietf.org
Subject: Re: [rtcweb] On video codec for rtcweb
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On Fri, Mar 23, 2012 at 8:34 AM, Timothy B. Terriberry <
tterriberry@mozilla.com> wrote:

> With a direct browser-to-browser connection, there is nothing sitting
> between them to do the transcoding. In the DTLS-SRTP case with identity
> verification, which I think a number of people here view as highly
> important, you are in fact _guaranteeing_ that nothing but the browser can
> encode or decode the video.
>

This is not technically correct. You can still build a system that
implements a media proxy that does nothing but handling ICE, encryption,
and identity verification without ever transcoding the content. The cost of
re-encrypting the media is low (ie single E5 Xeon CPU can probably do about
10GB/s), but the cost of transcoding video, or even audio is huge in
comparison. Because of this, supporting a comprehensive set of codecs is
highly desirable.
_____________
Roman Shpount

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