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Re: [codec] #1: Application: 2.1. Point to point calls supporting transcoding?

Marc Petit-Huguenin <petithug@acm.org> Sun, 28 March 2010 18:24 UTC

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Date: Sun, 28 Mar 2010 11:25:07 -0700
From: Marc Petit-Huguenin <petithug@acm.org>
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Subject: Re: [codec] #1: Application: 2.1. Point to point calls supporting transcoding?
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On 03/28/2010 11:03 AM, stephen botzko wrote:
>>>>
> Sorry, but I still do not understand the need for this testing.  In a cell
> network to VoIP topology, the codec selected must be an ITU codec which we
> already know are working fine for transcoding.
>>>>
> 
> We will NOT know if an ITU codec tandems with this codec with acceptable
> quality unless we test the combination.  The ITU does not warrant that
> their codecs will tandem with anything.  No one does.
> 
> And even in a VOIP framework, the audio will be transcoded sometimes. 
> At least some VOIP infrastructures are set up to use specific codecs
> (for instance G.729) and transcode anything else to that format.  And
> certainly this audio will be transcoded when it enters a cellular or
> PSTN network.
> 
> If you end up with a free internet codec, but everyone has to carry all
> the royalty-bearing codecs also (so that transcoding is never needed),
> then it seems to me that you are not accomplishing your goal.  I think
> tandeming has to be tested, precisely because we expect implementations
> to include devices which only support this codec.

Well, we will have to agree to disagree.

-- 
Marc Petit-Huguenin
Personal email: marc@petit-huguenin.org
Professional email: petithug@acm.org
Blog: http://blog.marc.petit-huguenin.org

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