[asterisk-dev] G.729.1 - any interest?

Kristian Kielhofner kristian.kielhofner at gmail.com
Wed Jan 14 11:40:18 CST 2009

On Wed, Jan 14, 2009 at 12:11 PM, John Todd <jtodd at digium.com> wrote:
> The G.729.1 "wideband" codec is starting to show a slight bit of
> traction.  There is a possibility that Asterisk could support G.729.1
> - would you use it or buy it if it was available?  More importantly,
> does any equipment with which your systems currently exchange traffic
> support G.729.1?  Currently, the number of devices supporting G.729.1
> seems to be fairly limited and it may be an imbalanced decision to
> support a codec that nobody else uses.
> If G.729.1 were to be offered as a codec for Asterisk by Digium, it
> would have to be as a commercial product, as the codec is patent-
> encumbered.  Pricing and licensing terms are outside the scope of this
> discussion, but I would expect something like G.729.  Of course,
> passthrough-mode (non-transcoding) would not require licensing with
> Asterisk and is outside of the scope of this question.  Timing is also
> an unknown issue - there are obviously many other projects in the
> pipeline for the Digium engineering team to work on before this
> probably could be completed, even if the decision is made to pursue a
> development effort.
> Note that G.722 is free and already available, and may have similar
> MOS scores (but certainly not exactly similar) as that of G.729.1.
> Comparisons of G.729.1 and G.722 are left as exercises to the reader,
> or see the excellent presentation below which is quite enlightening.
> Your opinions are welcome on the topic!
> Resources:
> http://portal.etsi.org/stq/workshop2007presentations/quinquis_slides.pdf
> http://en.wikipedia.org/wiki/G.729.1
> http://en.wikipedia.org/wiki/G.722
> [Apologies for the cross-post - this has some interest to both the
> user and development community, I think.  I'll also apologize for what
> is a post about issues that are not "open-source", but it seems that
> within Digium I'm probably the most appropriate person to canvass the
> community on this particular question, as it involves gauging the
> general thinking of the VoIP community and is not merely a Digium-only
> concern.]
> JT
> ---
> John Todd                       email:jtodd at digium.com
> Digium, Inc. | Asterisk Open Source Community Director
> 445 Jan Davis Drive NW -  Huntsville AL 35806  -   USA
> direct: +1-256-428-6083         http://www.digium.com/


  It looks like G729.1 is compatible with G.729.  I know Asterisk
currently only supports G.729a (reduced CPU usage with a slight
quality degredation) but this itself is directly compatible with G.729
so this shouldn't be an issue.

  It seems to me that if you were going to offer G.729.1 licenses if
you priced them identically (or similarly) to existing G.729a binaries
and processor performance didn't take too much of a hit, you could
potentially discontinue supporting/building/etc G.729a binaries in
favor of G.729.1 binaries.  Highly unlikely for various reasons but
possibly worth a try.

  Even if only Asterisk systems supported it along with a few other
devices it would be cool to have a codec that could do wideband with
another G.729.1 speaker (another Asterisk machine) yet still be useful
to those of us who largely interop with various bits of commercial
gear that only support G.729 and G.711u/a.  Who knows, maybe even more
commercial gear will support G.729.1 someday.  I imagine at least a
few vendors could be thinking the same way I am.

Kristian Kielhofner

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