[Linphone-developers] Incoming video garbled (H264, MP4V-ES), no video with VP8

[Jeremy Jongepier]

Hello,

I'm having issues with incoming videostreams (VP8, H264 and MP4V-ES) on 
Linphone. The set-up is as follows:

sipml5 |<-------- WebSocket -------->| webrtc2sip
       |<--------- WebRTC ---------->|
                                     |
Linphone |<-- SIP -->| Kamailio |<-->|
         |<-- RTP -->|

sipml5: http://sipml5.org/
webrtc2sip: http://webrtc2sip.org/

webrtc2sip functions as a gateway between WebRTC capable clients and 
clients that do not support WebRTC. It takes the WebRTC stream which in 
case of sipml5 consists of a RTP/SAVPF bundle with VP8 and G711 codecs 
and converts it to RTP/AVP and any codec it can convert (H264, H263, 
speex, GSM etc.).
This works great but Linphone has issues with the videostream it gets 
offered. H263 is no problem, that gets rendered normally, but H264 and 
MP4V-ES do not get rendered properly, the outcome looks garbled. VP8 
doesn't get rendered at all. The problem is probably not on the side of 
webrtc2sip as other SIP clients like Ekiga, Boghe or IMSDroid have no 
issues with rendering the incoming videostream when webrtc2sip has 
converted it to H264 or MP4V-ES or when it passes through the VP8 stream.
What is the best way to debug this issue? And all Linphone clients I've 
tested have these difficulties rendering the videostreams (Linphone 
3.5.2 for Windows and Ubuntu, Linphone 2.0.2 for Android).

Thanks in advance,

Jeremy