[Freeswitch-users] absolute_codec_string question

Paul Cupis paul at cupis.co.uk
Mon Apr 25 20:45:49 MSD 2011


On 25/04/11 17:22, Nicolas Brenner wrote:
> You are totally right, I was looking for the a=rtpmap:18 G729/8000 line. I
> find it weird that it is automatically inserted for SPEEX, but not for other
> codecs.

SPEEX does not have an IANA allocated mapping, so used dynamic mapping
(98 is within the dynamic range) - dynamically mapped codecs must be
specified verbosely in the SDP.

> Another thing I noticed, is I can't specify more than one codec, according
> to what I've read about other issues, this has something to do with a comma
> parsing problem on the console (for some reason commas can't be escaped,
> this also affects trying to originate calls from ESL).
> 
> So for absolute_codec_string=G729 I get this SDP (with verbose_sdp=true):

Try something like:

 {absolute_codec_string='G729,PCMU'}

The quoting of the codecs should mean that the comma is "escaped" and
therefore both codecs will be offered.

Regards,



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