[FFmpeg-devel] [PATCH] RTP local udp port issue fix (ticket 916)

Michael Niedermayer michaelni at gmx.at
Mon Jan 16 19:51:13 CET 2012

On Mon, Jan 16, 2012 at 08:55:18PM +0400, Dmitry Volyntsev wrote:
> Abstract: Ffmpeg doen't check that udp port which it selects for
> incoming rtp already receives packets
> Detailed description, steps to reproduce and ffmpeg logs and wireshark
> logs of the issue: https://ffmpeg.org/trac/ffmpeg/ticket/916
> Description: RTSP session brakes some times and rstp server doesn't
> receive any notification about it and still sends packet in rtp
> session. new ffmpeg instance request the same port for incoming
> streams and doesn't detect it, it receives two stream simultaneously
> but tries constantly re-synchronize with two interleaved streams.
> I've checked what other implementation of RTP/RTSP do in this case.
> 1) LIVE555 library (inside vlc media player)
> 2) gstreamer framework
> Both of them just request no udp port from special range, but use port
> which an OS provides.
> It this case local udp ports grow sequentially and issue case doesn't
> occur. The remote side after some period of time stops sending packets
> to old ports.

from your description and my limited knowledge of RTSP the patch looks
good. I dont understan though why the code didnt do this originally

maybe luca can comment ?

Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Complexity theory is the science of finding the exact solution to an
approximation. Benchmarking OTOH is finding an approximation of the exact
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 198 bytes
Desc: Digital signature
URL: <http://ffmpeg.org/pipermail/ffmpeg-devel/attachments/20120116/315e7e8f/attachment.asc>

More information about the ffmpeg-devel mailing list