[Linphone-developers] Found bug in handle unknown media stream

[Evgeny Nesterov]

Hello!

As it appears i found bug in library. When server in invite session send 
media stream "application", library think that this is audio stream, 
what is causing the problem under Android.

Server send invite message:

> INVITE sip:138@81.200.17.190:34090 SIP/2.0
> Via: SIP/2.0/UDP 178.76.234.90:5060;branch=z9hG4bK74da54d1;rport=5060
> Contact: <sip:178.76.234.90;transport=UDP>
> To: <sip:138@81.200.17.190:34090>
> From: "132" <sip:132@178.76.234.90>;tag=as477f9fb
> Call-ID: 2e28ada327693177239117a54ee43039@178.76.234.90
> CSeq: 102 INVITE
> User-Agent: VINTEO 2.0.0
> Max-Forwards: 70
> Date: Fri, 09 Oct 2020 10:25:52 GMT
> Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, SUBSCRIBE, NOTIFY
> Content-Type: application/sdp
> Content-Length: 516
>
> v=0
> o=root 21505 21505 IN IP4 178.76.234.90
> s=session
> c=IN IP4 178.76.234.90
> b=CT:1536
> b=AS:1536
> t=0 0
> a=vnd.vinteo.fec:v=2.0.0
> m=audio 20014 RTP/AVP 0 101
> a=rtpmap:0 PCMU/8000
> a=rtpmap:101 telephone-event/8000
> a=silenceSupp:off - - - -
> m=video 20016 RTP/AVP 99
> b=AS:1536
> b=TIAS:1536000
> a=content:main
> a=label:2
> a=rtpmap:99 H264/90000
> a=fmtp:99 profile-level-id=42001F
> a=rtcp-fb:* nack pli
> a=rtcp-fb:* ccm fir
> a=sendrecv
> m=application 20020 RTP/AVP 100
> a=sendrecv
> a=rtpmap:100 H224/4800
After this we can see in logs (show only significant lines):

> 2020-10-09 13:28:01:430 [liblinphone] MESSAGE Found payload H224/4800 
> fmtp=
> 2020-10-09 13:28:01:436 [liblinphone] MESSAGE Created stream#0 [audio] 
> in state [Stopped]
> 2020-10-09 13:28:01:444 [liblinphone] MESSAGE Created stream#1 [video] 
> in state [Stopped]
> 2020-10-09 13:28:01:448 [liblinphone] MESSAGE Created stream#2 [audio] 
> in state [Stopped]
> 2020-10-09 13:28:03:182 [liblinphone] MESSAGE Declining mline 2, no 
> corresponding stream in local capabilities description.

Stream #2 has type 'audio', though it must be of type 'other'. I don't 
know why, but this error causes that there is no incoming sound on android.

--
Evgeny Nesterov