Re: [rtcweb] Call for Consensus Regarding Selecting Recommended Audio Codecs

[Andrew Allen <[e-mail]>]

I really still don't see what the value is as part of RTCweb in describing the other codecs that are used by other VoIP and audio over IP and other digital audio systems and the perceived pros and cons of each.

This information is commonly available - just type codecs on wikipedia and you will get a large list of many of the commonly used audio codecs and where they are used and what the perceived royalty situation is. For the real information you will have to go to the organisations that specify the codecs in any case.

I think it should be obvious that if the device is a 3GPP mobile device then it will also support the 3GPP codecs and IETF doesn't need to tell RTCweb implementors that. It should also be obvious that if you want to interoperate without transcoding with 3GPP devices then you should take a look at the 3GPP codec specifications.

I don't think IETF and certainly not RTCweb should embark on duplicating information that is available elsewhere from the organisations that own and have the expertise on those codecs. Any information documented in IETF on this even if accurate to begin with is likely to become rapidly out dated as new codecs are developed and as patents expire. 

Also I doubt very much this will end up being limited to just AMR-NB, AMR-WB and G.722. Once we go down the path of saying RTCweb is going to document the other codecs that implementations should consider supporting for optimal interoperability I expect many more wil be added to the list as most of the codecs still in use have legacy terminals in some deployment somewhere that someone will think it is a good idea to interoperate with. I think this will get out of hand and either will become a long list of codecs or become a huge discussion about which are important and which are not. 

I think this is a waste of time and a distraction from solving the real interoperability issues like agreeing a common video codec and making sure JSEP and SIP/SDP interoperate well together.

I think its enough in RTCweb just to state that for best interoperability also supporting additional codecs commonly used in other deployments that there is a desire to interoperate with is a good thing in order to avoid the issues of transcoding. 

Then let implementors and the market decide which other codecs are important to implement.

Andrew

----- Original Message -----
From: Hutton, Andrew [mailto:[e-mail]]
Sent: Friday, January 04, 2013 04:47 AM Central Standard Time
To: Andrew Allen; Harald Alvestrand <[e-mail]>; [e-mail] <[e-mail]>
Subject: RE: [rtcweb] Call for Consensus Regarding Selecting Recommended Audio Codecs

I previously indicate support for 1) but I note the arguments put forward by Adam Roach and agree that normative recommendations for additional codec's are not necessary here.

However I think it would be helpful to have some non normative text describing how the implementation of particular codec's would improve interoperability in specific environments (E.g. mobile) and although this could be left to browser vendors to work out for themselves I don't think that is a good argument for not doing it. We are here to promote interoperability after all.

I also disagree that the MTI codec's already agreed are sufficient to ensure interoperability with non RTCWEB environments which according to the rtcweb charter should be considered.

Regards
Andy



> -----Original Message-----
> From: [e-mail] [mailto:[e-mail]] On
> Behalf Of Andrew Allen
> Sent: 03 January 2013 17:25
> To: Harald Alvestrand; [e-mail]
> Subject: Re: [rtcweb] Call for Consensus Regarding Selecting
> Recommended Audio Codecs
> 
> I also support 2)
> 
> I really don't think it helps much to describe what other codecs are
> out there that you might want to think about implementing if you want
> to interoperate with certain other non RTCweb deployments. I think
> anybody who is seriously thinking about developing such a product can
> easily find this out for themselves - if you want to interoperate with
> 3GPP devices then take a look at the CURRENT 3GPP Codec specifications!
> 
> It should be realized that the codec life cycle tends to be somewhat
> shorter than that of the signaling technology so the codec information
> is likely to become out of date long before the signaling
> specifications become obsolete (possibly already dated by the time the
> RFC is published) - 3GPP is already working on a new codec for LTE!
> 
> As everyone has a favorite codec they would like to see deployed the
> downside of this is that this will likely become a distraction that
> generates a lot of discussion and consumes a lot of cycles that would
> be better spent on addressing the basic interoperability issues facing
> RTCweb.
> 
> So I think the MTI audio codecs already agreed is enough to ensure
> interoperability.
> 
> Andrew
> 
> -----Original Message-----
> From: [e-mail] [mailto:[e-mail]] On
> Behalf Of Harald Alvestrand
> Sent: Thursday, December 27, 2012 11:33 AM
> To: [e-mail]
> Subject: Re: [rtcweb] Call for Consensus Regarding Selecting
> Recommended Audio Codecs
> 
> Speaking as an individual:
> 
> I am putting my name on 2), because I believe RECOMMENDED is too strong
> for secondary codecs.
> 
> On 12/20/2012 09:29 AM, Magnus Westerlund wrote:
> > WG,
> >
> > As an outcome of the Vancouver IETF meeting codec discussions we did
> > promise to run a call for consensus regarding if the WG was
> interested
> > in specifying a small set of recommended audio codecs. We are sorry
> > this has been delayed until now.
> >
> > The question for the call of consensus is between two options.
> >
> > 1) Run a process in the WG to select and specify a small set of
> > audio/speech codecs that would be RECOMMNEDED to implement by a
> WebRTC
> > end-points
> >
> > 2) Do nothing and let the already specified Mandatory to Implement
> > Audio codecs be the only audio codecs mentioned in the WebRTC
> specification.
> >
> > Please indicate your position by January 16th 2013.
> >
> > Regards
> >
> > Magnus Westerlund
> >
> > ---------------------------------------------------------------------
> -
> > Multimedia Technologies, Ericsson Research EAB/TVM
> > ---------------------------------------------------------------------
> -
> > Ericsson AB                | Phone  [phone]
> > Färögatan 6                | Mobile [phone]
> > SE-164 80 Stockholm, Sweden| mailto: [e-mail]
> > ---------------------------------------------------------------------
> -
> >
> > _______________________________________________
> > rtcweb mailing list
> > [e-mail]
> > https://www.ietf.org/mailman/listinfo/rtcweb
> 
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