git bisect good
bc2a32969eb4db17677971def5ad5b936d9d1648 is the first bad commit
commit bc2a32969eb4db17677971def5ad5b936d9d1648
Author: Martin Storsjö <martin@martin.st>
Date:   Tue Dec 4 15:28:29 2012 +0200

    rtsp: Parse SSRC attributes in the SDP

    When feeding input RTP packets to the depacketizer via custom IO,
    it needs to pick the right stream using the payload type for
    RTP packets, and using the SSRC for RTCP packets. If the first
    packet is an RTCP packet, we don't (currently) know the SSRC
    yet and thus can't pick the right RTP depacketizer to handle it.

    By parsing the SSRC attribute in the SDP, we can map initial
    RTCP packets to the right stream.

    Signed-off-by: Martin Storsjö <martin@martin.st>

:040000 040000 5c5f439a7ed8b842c97d679bb7fd0959c55989d3 5ea316170ba85975093d0ba2ce0a22e472516259 M	libavformat