Subject: Re: [rtcweb] Should we also make G.722 a mandatory to implement codec?

From: Tim Panton <[email-masked]>
Date: Wed, 1 Aug 2012 12:33:21 +0200

I (personally) am against making g711 or g722 MTI audio codecs. There are network environments where they will behave significantly worse than opus (in silk mode). Neither codec will adapt to variable available bandwidth or cope well with packet loss -as seen on the edge of wifi networks and on 3G networks . 

We should not be encouraging the use of legacy codecs by making them MTI. 

When I mentioned H261 as a compromise MTI video codec, I was told that better codecs existed and that we should adopt them. Same goes for audio. 

Tim.  

Sent from my iPhone

On 30 Jul 2012, at 20:48, "Kevin P. Fleming" <[email-masked]> wrote:

> On 07/30/2012 12:21 PM, Roman Shpount wrote:
>> Should we consider adding G.722 as a mandatory to implement audio codec?
>> It is low complexity and carries no royalty or license restrictions, it
>> is very good quality for voice audio communications at the
>> same bandwidths as G.711, and it is very widely implemented by the
>> desktop IP phones.
> 
> I would certainly support making G.722 mandatory to implement.
> 
> -- 
> Kevin P. Fleming
> Digium, Inc. | Director of Software Technologies
> Jabber: [email-masked] | SIP: [email-masked] | Skype: kpfleming
> 445 Jan Davis Drive NW - Huntsville, AL 35806 - USA
> Check us out at www.digium.com & www.asterisk.org
> _______________________________________________
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---

From: Roman Shpount <[email-masked]>
Date: Wed, 1 Aug 2012 11:24:15 -0400

I personally think it would be a mistake not to require G.711 and G.722.
Even though OPUS can be better under some circumstances, it is much more
expensive to encode, has no deployed base, and might proof to be patent
encumbered.

The CPU resources to encode or transcode to OPUS are several orders of
magnitude more then for G.711 and G.722. If we need to communicate with
legacy equipment, the cost to transcode from OPUS to G.711 or G.722 might
be prohibitive. Also, if we need to transcode to other low bitrate codecs,
such as AMR, it would require half the resources to transcode between G.722
and AMR vs OPUS and AMR.

Even though OPUS is supposed to be an unencumbered codec, it is not
unfeasible for some party to step forward and claim intellectual property
rigts that OPUS is using. In this case we might have no recourse but to pay
royalties. G.711 and G.722 are guaranteed not to be encumbered in any way
since they been in use long enough for any IP claims to expire.

Finally, OPUS is still in a draft phase, so there is no or little
deployment experience with it. We might still discover things that will
negatively affect it in some way. G.711 and G.722 are very widely deployed
and all the issues related to it are well known. In a lot of cases they are
simply good enough.

P.S. This is in no way an argument against OPUS. I think we should make it
mandatory and hope for the best, but I think we should also have easy to
implement, widely deployed, unencumbered codecs supported as well.
_____________
Roman Shpount

On Wed, Aug 1, 2012 at 6:33 AM, Tim Panton <[email-masked]> wrote:

> I (personally) am against making g711 or g722 MTI audio codecs. There are
> network environments where they will behave significantly worse than opus
> (in silk mode). Neither codec will adapt to variable available bandwidth or
> cope well with packet loss -as seen on the edge of wifi networks and on 3G
> networks .
>
> When I mentioned H261 as a compromise MTI video codec, I was told that
> better codecs existed and that we should adopt them. Same goes for audio.
>
> Tim.
>
> Sent from my iPhone
>