RE: [Iaxclient-devel] codec support

[Steven S. <ss...@so...>]

> I'm new to this list. Can somebody update me with info: is any work 
> done for supporting codec other them GSM. I'm interesting on adding iLBC
codec.

We've talked about adding support for iLBC, SpeeX and possibly LPC-10.  We
also need to put in support for the wasteful but ubiquitous G.711 a/u.
Before we do that, we need to work out:

1.  A modular framework for adding codecs to iaxClient
2.  How to negotiate codecs over IAX2
3.  Which codecs we want and in what order

Can everybody vote for their favorite codecs?  Here's my list in order of
preference:

1.  g711 a/u  - Makes us compatible with nearly everything
2.  iLBC      - Integrates us with Firefly network, plus others.
3.  SpeeX     - Low bandwidth, free, unencumbered
4.  ADPCM/G.723	- NOT G.723.1 (patented) but the old, free version
5.  G.726/32	- The new codec added by Mark to Asterisk
6.  LPC-10		- Because it was there...

We may also want to consider creating a plug-in module to add G.729-C (the
pseudo-free version of G.729 for non-commercial use).  We need to read the
license very carefully and perhaps it would require the end user to compile
their own .so/.dll to make use of this.

I wonder if there is a way to create a commercial G.729 plug-in that can be
sold via Digium?  If we have a common codec interface that is common across
all clients, couldn't we create a standard binary dynamic link format for
each platform (x-nix, Windows, Mac) and ask Digium to sell the plug-ins?

In any case, yes, I would love to see multiple codecs supported.  But before
we rush in, we need to agree on a modular format that, hopefully, can be
used to support _any_ codec.

Steve

Steven Sokol
Owner/Manager
Sokol & Associates, LLC

Phone:  816.822.1807
IaxTel: 700.613.9004
Web:    http://www.sokol-associates.com