[Spce-user] G.729 codec is being removed from the answer SDP

[Rahul Dhuri]

Hi,

Looking for some suggestion on the scenario below and see what our options are.

We see RtpEngine deletes the G729 codec from the 'answer' when there is a mismatch in the 'annexb' attribute of G729.  The original Invite was with annexb=yes attribute, and the 183 response from B party is coming back with annexb=no attribute.

I see below message in RTPEngine logs, which looks like this is done on purpose.

[1770617053.569755] DEBUG: [159450353296313653]: [codec] Not adding stray answer codec G729/8000/annexb=no (18)


Is there a way so that RTPengine does not delete the G729 codec in this case ?


RtpEngine response of command 'offer':
====================
t=0 0
m=audio 44234 RTP/AVP 18 8 0 96
a=maxptime:40
a=rtpmap:18 G729/8000
a=fmtp:18 annexb=yes
a=rtpmap:8 PCMA/8000
a=rtpmap:0 PCMU/8000
a=rtpmap:96 telephone-event/8000
a=fmtp:96 0-15
a=sendrecv
a=rtcp:44235

183 response from B-party:
====================
t=0 0
m=audio 15036 RTP/AVP 18 96
a=rtpmap:18 G729/8000
a=fmtp:18 annexb=no
a=rtpmap:96 telephone-event/8000
a=fmtp:96 0-15
a=sendrecv
a=maxptime:20

RtpEngine response of command 'answer':
==================================
c=IN IP4 172.28.0.5
t=0 0
m=audio 30266 RTP/AVP 96
a=maxptime:20
a=rtpmap:96 telephone-event/8000
a=fmtp:96 0-15
a=sendrecv
a=rtcp:30267


Thanks,
Rahul

Rahul Dhuri
Senior Software Engineer
Erahul.dhuri at symbio.global
W
symbio.global
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