On 06/04/2010 02:27 AM, Kyle Kienapfel wrote: > http://en.wikipedia.org/wiki/G.729 > Looks like theres A and B and no "A/B" so theres nothing to worry about > What's the point of quoting a page, if you are not actually going to read it? > On Thu, Jun 3, 2010 at 9:09 AM, Alejandro Cabrera Obed > <[email protected]> wrote: > >> Dear all, I've read that Asterisk supports only the G.729 A audio >> codec. I have several Grandstream IP phones with G.729 A/B codec >> implementation. >> >> Does G.729 A/B mean both version A and version B, or A/B is a new >> version different from A and B and it's not supported by Asterisk ??? >> G.729 is the base codec, which hardly anyone uses
G.729 Annex A is a stripped down version which doesn't sound as good, but takes only half the compute power. This is the one almost everyone uses - who cares about voice quality, anyway? The bit stream is identical to G.729, so they are fully interworkable. For thos reason SDP does not distinguish between G.729 and G.729A. G.729 Annex B is a CNG/VAD add on for either of the above codecs. This feature may be turned on and off in the SDP, using the annexb parameter. A codec which cannot support Annex B is, therefore, always able to interwork with a codec that does support it. G.729AB or G.729A/B are the usual ways people described a codec which uses the Annex A version of the encoding and decoding, and which supports CNG/VAD. Steve -- _____________________________________________________________________ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- New to Asterisk? Join us for a live introductory webinar every Thurs: http://www.asterisk.org/hello asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
