Re: [rtcweb] RTCWEB needs an Internet Codec

On Aug 31, 2012 8:13 AM, "John Leslie" <john@jlc.net> wrote:
>
> Randell Jesup <randell-ietf@jesup.org> wrote:
> >
> > If you're talking audio-only calls, I agree - but for audio+video, you
> > want a lot of bandwidth available for video.  If the user has 128Kbps, I
> > don't want 56K of that devoted to audio; I probably want 15-25K for
> > audio (which can give good wideband or better performance with Opus),
> > and the rest for video.  I probably wouldn't open audio up to 56 or 64K
> > (using Opus) below 300-500K of total bandwidth, because of diminishing
> > rate of improvement over ~25K.
>
>    128Kbps is marginal for audio+video, yes.
>
>    However, I don't believe it wise for us to try to standardize anything
> about the audio-vs-video tradeoff.
>
>    I will state my opinion that good audio plus one frame per second is
> better in a conferencing environment than bad audio plus 128Kbps of
> video; but I'd never impose that choice on anyone else.
>
>    The point is: G.711 is suboptimal, yes, but not unusable.
>
>    Our issue here is Mandatory-to-Implement. It is very important to
> have at least one MTI audio codec. I could live with that being G.711,
> because I trust the market to _actually_ implement others.
>

Agree with the above. G.711 for mti only.

I want to push Opus and promote its use, but MTI is not the right method
for that.

CB

> > Having a *good* low-bitrate (and adaptable) audio codec is *critical*
> > to having a good solution for video.
>
>    I'm not sure I agree, though it is certainly _very_ helpful.
>
> > Without that all the cases that involve video are blown below 100's
> > of Kbps; with a good low-bandwidth codec you can do video calls
> > with 100Kbps or even less.
>
>    I'm not sure even this will remain true for five years.
>
>    But I am sure that the market will implement Opus or something
> like it within five years without our needing to call it MTI.
>
> > This is why I support Opus (+G.711 for legacy interop and testing)
> > for MTI.
>
>    This _is_ a good argument: I don't mean to ridicule it.
>
>    But we need to reach closure on this. If enough people are scared
> of the IPR questions of Opus, I'm willing to retreat to a SHOULD
> implement Opus.
>
> --
> John Leslie <john@jlc.net>
> _______________________________________________
> rtcweb mailing list
> rtcweb@ietf.org
> https://www.ietf.org/mailman/listinfo/rtcweb