[MEncoder-users] problem dumping an RTSP stream

[Kasper Bonne]

Hi List

I have a problem dumping an RTSP stream. I'm out of ideas of what to
try so I'll quickly describe the procedure I went through and maybe
one of you have the solution. The stream I want to dump plays fine
with no switches and the video and audio is correctly identified:


--- OUTPUT ---------------------
Initiated "video/H264" RTP subsession on port 52514
Initiated "audio/X-QT" RTP subsession on port 50526
demux_rtp: Guessed the video frame rate as 30 frames-per-second.
        (If this is wrong, use the "-fps <frame-rate>" option instead.)
VIDEO:  [H264]  0x0  0bpp  30.000 fps    0.0 kbps ( 0.0 kbyte/s)
==========================================================================
Opening video decoder: [ffmpeg] FFmpeg's libavcodec codec family
Selected video codec: [ffh264] vfm: ffmpeg (FFmpeg H.264)
==========================================================================
==========================================================================
Opening audio decoder: [pcm] Uncompressed PCM audio decoder
AUDIO: 48000 Hz, 2 ch, s16le, 0.0 kbit/0.00% (ratio: 0->192000)
Selected audio codec: [pcm] afm: pcm (Uncompressed PCM)
==========================================================================
--- END OUTPUT -----------------


However, if I add -dumpstream (and -dumpfile) mplayer complains:


--- OUTPUT ---------------------
Cannot dump this stream - no file descriptor available.

Exiting... (Fatal error)
--- END OUTPUT -----------------


I thought, since the stream consists of two separate RTP sub sessions
on two different ports, that maybe it would work if I dumped only the
video and later only the audio. That did seem to work, at least I got
the following output:


--- OUTPUT ---------------------
Stream not seekable!
 file format detected.
Initiated "video/H264" RTP subsession on port 61272
Initiated "audio/X-QT" RTP subsession on port 64168
demux_rtp: Guessed the video frame rate as 30 frames-per-second.
        (If this is wrong, use the "-fps <frame-rate>" option instead.)
VIDEO:  [H264]  0x0  0bpp  30.000 fps    0.0 kbps ( 0.0 kbyte/s)
--- END OUTPUT -----------------


The problem is now that I can't play the dumped files. I assume that
it's because they contain some sort of RTSP header or something but
even if that is the case, shouldn't the h264 file contain
synchronization points?

I'm at a loss of what to do. Is there a different way of dumping the
stream? I even tried mencoder:


--- OUTPUT ---------------------
$> mencoder -oac copy -ovc copy -o output.avi rtsp://blablablabla...
Server returned 503: error
No stream found to handle url rtsp://blablablabla...
Cannot open file/device.

Exiting...
--- END OUTPUT -----------------


Hope you can help.

Best
/Kasper