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RTSP/RTCP NACK Packet Retransmission Request (RFC 4585,4588)

Posted: 11 Mar 2013 17:56
by amuehlf2
Is it possible to configure VLC to request retransmission of lost packets? Specifically, I have the following two RFCs in mind:

RFC 4588 "RTP Retransmission Payload Format"
http://datatracker.ietf.org/doc/rfc4588/

RFC 4585 "Extended RTP Profile for Real-time Transport Control Protocol (RTCP)-Based Feedback (RTP/AVPF)
http://tools.ietf.org/html/rfc4585

I am using VLC as a client to open a video stream using RTSP (which sends RTP packetes over unicast UDP). Using wireshark, I can see VLC sending Receiver Report (RR) packets over the RTCP protocol every 5 seconds. However, when I drop packets I don't see the NACK packet, which is assigned for retransmission requests. Is there an option to enable retransmission requests?

Thanks.

Ubuntu Linux 11.04
VLC 1.1.9

(Please forgive me if this belongs in the feature request forum, I'm hoping the feature exists and I just haven't found it yet).

Re: RTSP/RTCP NACK Packet Retransmission Request (RFC 4585,4

Posted: 14 Mar 2013 17:38
by RĂ©mi Denis-Courmont
As the moment, VLC relies on the live555 library for RTSP playback. But in any case, I do not know any standard way to negotiate AVPF via RTSP. I think this profile is mainly intended for SIP rather than RTSP so far.