[FFmpeg-devel] network / ipv6 / ... maintainer needed

Luca Abeni lucabe72
Fri Oct 5 15:58:44 CEST 2007

Hi Ronald,

Luca Abeni wrote:
> what my application does is similar to
> ffmpeg -re -i test.mpg -vcodec copy -an -f rtp rtp:// -vn -acodec copy -f rtp rtp:// -newaudio
Sorry, I forgot "-fflags genpts". Add it as a first parameter for ffmpeg.

> But I have some bad news for you: I see that I have "--disable-ipv6" in all
> my build scripts... I do not remember why. I am going to check, and I'll
> let you know.
Ok, I did some tests and networking does not seem to work unless IPV6 is
luca at nowhere:/tmp/ffmpeg$ ./ffmpegv6 -fflags genpts -re -i /tmp/test.mpg -vcodec copy -an -f rtp rtp:// -vn -acodec copy -f rtp rtp:// -newaudio
FFmpeg version SVN-r10668, Copyright (c) 2000-2007 Fabrice Bellard, et al.
   libavutil version: 49.5.0
   libavcodec version: 51.44.0
   libavformat version: 51.14.0
   built on Oct  5 2007 15:30:46, gcc: 4.1.2 (Ubuntu 4.1.2-0ubuntu4)
Input #0, mpeg, from '/tmp/test.mpg':
   Duration: 00:04:07.0, start: 0.500000, bitrate: 270 kb/s
   Stream #0.0[0x1e0]: Video: mpeg1video, yuv420p, 320x240, 104857 kb/s, 25.00 fps(r)
   Stream #0.1[0x1c0]: Audio: mp2, 44100 Hz, stereo, 64 kb/s
bind: Permission denied
Could not open 'rtp://'

If I execute the command as root, the error message changes in
   Stream #0.1[0x1c0]: Audio: mp2, 44100 Hz, stereo, 64 kb/s
bind: Address already in use
Could not open 'rtp://'

But if I stream only video, with
sudo ./ffmpegv6 -fflags genpts -re -i /tmp/test.mpg -vcodec copy -an -f rtp rtp://
then, it works (streaming as non root fails, again). So, I suspect that
the "IPv6 probing code" (or the code that is run to decide if streaming
over IPv6 or over IPv4) tries to bind a socket below 1024 (or perform
some kind of privileged operation)?
And maybe it does not close the socket after probing? I am just guessing...

I tried ffserver too, and it has similar problems: if I run it as non root,
I get "bind: Permission denied" (repeated two times) every time that I try
to connect with an RTSP client. If I run it as root, I get one single
error ("bind: Address already in use") and ffserver streams only video.

If I compile with "--disable-ipv6", everything works fine. I have this option
in my scripts since years, so I do not know if IPV6 ever worked for my
testcases... Sorry.


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