[sr-dev] [SR-Users] Video Key-Frame Request using RTCP FIR or SIP INFO message

[Olle E. Johansson]

On 29 Jan 2015, at 23:56, Muhammad Shahzad <shaheryarkh at gmail.com> wrote:

> Hi,
> 
> This may be a bit out of focus topic for this forum but i am posting it here anyway with hope that some guru would shed some light on it and point me to right direction.
> 
> The problem is that i want to establish video call between a webrtc and a sip client using kamailio (for signalling) and RTPEngine (for media relay). Both signalling and the audio stream seems to work perfectly fine The remote video on webrtc client side (i.e. video stream from sip client) takes about 20-30 seconds to establish but once it starts it works fine. However, the remote video on sip client side (i.e. video stream from webrtc client) starts almost immediately (within 3-5 seconds) but it gets stuck after 1 or 2 seconds, then it goes blank after about 30 seconds.
> 
> After a long discussion with sip client developer, we now understand the fact that sip client sends a request for so called key-frame, which is ignored by webrtc client. This request is sent through both RTCP stream and SIP INFO message.
> 
> The SIP INFO message seems to be pointless as media is internally managed by chrome/firefox and these browsers don't give us such sophisticated access and control over media streams. Please let me know if this assumption is wrong.
> 
> For the RTCP stream based request (RTCP-FIR), i only see "Invalid RTCP packet type" error message in RTPEngine logs (not sure if it drops this packet or relay it anyway).
> 
> Does anyone has any idea on how can we either,
> 
> 1. Force WebRTC client (running on Chrome / Firefox) to honor SIP INFO message and issue a key-frame in RTP video stream in response to this SIP request?
Talk with the SIP stack developer. I don't know if it's possible at all and I think using SIP info for this is 
more or less the old way. Sending it in the actual media stream feels like a more modern and better way.
> 
> OR
> 
> 2. Force RTPEngine to accept RTCP-FIR and issue key-frame in RTP video stream on webrtc client's behalf?
File a bug report with the RTPengine team. It's clearly something they need to support.

/O


> 
> If there is any other solution to this, please feel free to share.
> 
> 
> Thank you.
> 
> 
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