[Freeswitch-dev] Codec change from PCMA to PCMU within a running freeswitch session

Brian West brian at freeswitch.org
Fri Mar 7 16:51:49 MSK 2014


Sounds like you need to test against master, if the problem is still there then you’ll need to report a bug on jira.freeswitch.org.

--
Brian West
brian at freeswitch.org
FreeSWITCH Solutions, LLC
PO BOX 2531
Brookfield, WI 53008-2531
Twitter: @FreeSWITCH , @briankwest
http://www.freeswitchbook.com
http://www.freeswitchcookbook.com

T: +1.918.420.9001  |  F: +1.918.420.9002  |  M: +1.918.424.WEST
iNUM: +883 5100 1420 9001
ISN: 410*543
Skype:briankwest
PGP Key: http://www.bkw.org/key.txt (AB93356707C76CED)













On Mar 7, 2014, at 5:41 AM, Achim Stamm <stamm at lyth.de> wrote:

> Hello!
>  
> I have following problem:
>  
> My current session is connected to a third-party Application by using an own Freeswitch application "DoingReadAndWriteFrames". The communication between Freeswitch Session and third-party application is done by reading and writing frames in a while loop.
> At start of Freeswitch session the codec is PCMA, which I need for voice recognition.
> Customer reports, that the codec of the Freeswitch session changes from PCMA to PCMU.
> If an external call comes in, I’m playing an audio ringing tone into the Freeswitch session.
> I have realize, that the codec is changed back from u-law to a-law.
> I have recorded the voice stream and I have heard the codec change.
> I have never reproduced the codec change of an active Freeswitch session on my test system.
> Some customer reports, that the system is running fine (no codec change) for half a year.
>  
> My own bug fix is to manually translate PCMU data to PCMA, if session codec is switched to PCMU.
> But I cannot test my bug fix, because I can't force the changing of codec within a running session.
>  
> Maybe the "codec change" was a bug from Freeswitch version at October 2010.
> Maybe the hardware SPA3102 sends a sip re-invite message on special cases.
> I have no idea.
> I have some questions about codec negotiation and sip re-invite:
>  
> A) On what reasons can a re-invite message triggered and why is the session codec changed?
>  
> B) What must be happen, that a codec is changing, after a codec negotiation was done, on a running Freeswitch session?
>  
> C) Why is there a codec change back to a-law, when I’m playing an own ringing tone?
>  
> D) Is there a solution for forcing Freeswitch always use PCMA?
> My configuration of Freeswitch in “vars.xml” to force codec PCMA:
> <X-PRE-PROCESS cmd="set" data="global_codec_prefs=PCMA"/>
> <X-PRE-PROCESS cmd="set" data="outbound_codec_prefs=PCMA"/>
>  
>  
> Greetings
>  
> Achim Stamm
> _________________________________________________________________________
> Professional FreeSWITCH Consulting Services:
> consulting at freeswitch.org
> http://www.freeswitchsolutions.com
> 
> 
> 
> 
> Official FreeSWITCH Sites
> http://www.freeswitch.org
> http://wiki.freeswitch.org
> http://www.cluecon.com
> 
> FreeSWITCH-dev mailing list
> FreeSWITCH-dev at lists.freeswitch.org
> http://lists.freeswitch.org/mailman/listinfo/freeswitch-dev
> UNSUBSCRIBE:http://lists.freeswitch.org/mailman/options/freeswitch-dev
> http://www.freeswitch.org




Join us at ClueCon 2013 Aug 6-8, 2013
More information about the FreeSWITCH-dev mailing list