[FFmpeg-user] ffmpeg record only 25 secs of audio from RTSP

[Somsak Sriprayoonsakul]

Hello,

I want to dump the RTSP stream from my AVTECH AVM328B IP Camera. ffmpeg can
probe the stream but the recorded stream only has first 25 seconds of audio
for some reason.

My ffmpeg version

ffmpeg version 1.2.1 Copyright (c) 2000-2013 the FFmpeg developers
  built on May 27 2013 02:00:54 with gcc 4.4.7 (GCC) 20120313 (Red Hat
4.4.7-3)
  configuration: --prefix=/usr --libdir=/usr/lib64 --shlibdir=/usr/lib64
--mandir=/usr/share/man --enable-shared --enable-runtime-cpudetect
--enable-gpl --enable-version3 --enable-nonfree --enable-postproc
--enable-avfilter --enable-pthreads --enable-x11grab --enable-vdpau
--disable-avisynth --enable-frei0r --enable-libopencv --enable-libdc1394
--enable-libfaac --enable-libgsm --enable-libmp3lame --enable-libnut
--enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg
--enable-librtmp --enable-libspeex --enable-libtheora --enable-libvorbis
--enable-libvpx --enable-libx264 --enable-libxavs --enable-libxvid
--extra-cflags='-O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions
-fstack-protector --param=ssp-buffer-size=4 -m64 -mtune=generic -fPIC'
--disable-stripping
  libavutil      52. 18.100 / 52. 18.100
  libavcodec     54. 92.100 / 54. 92.100
  libavformat    54. 63.104 / 54. 63.104
  libavdevice    54.  3.103 / 54.  3.103
  libavfilter     3. 42.103 /  3. 42.103
  libswscale      2.  2.100 /  2.  2.100
  libswresample   0. 17.102 /  0. 17.102
  libpostproc    52.  2.100 / 52.  2.100


The command that I used

ffmpeg -i rtsp://172.20.20.15/live/mpeg4_ulaw/HD720P -acodec copy -vcodec
copy /var/tmp/test_copy.mov


ffprobe output of the stream

ffprobe version 1.2.1 Copyright (c) 2007-2013 the FFmpeg developers
  built on May 27 2013 02:00:54 with gcc 4.4.7 (GCC) 20120313 (Red Hat
4.4.7-3)
  configuration: --prefix=/usr --libdir=/usr/lib64 --shlibdir=/usr/lib64
--mandir=/usr/share/man --enable-shared --enable-runtime-cpudetect
--enable-gpl --enable-version3 --enable-nonfree --enable-postproc
--enable-avfilter --enable-pthreads --enable-x11grab --enable-vdpau
--disable-avisynth --enable-frei0r --enable-libopencv --enable-libdc1394
--enable-libfaac --enable-libgsm --enable-libmp3lame --enable-libnut
--enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg
--enable-librtmp --enable-libspeex --enable-libtheora --enable-libvorbis
--enable-libvpx --enable-libx264 --enable-libxavs --enable-libxvid
--extra-cflags='-O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions
-fstack-protector --param=ssp-buffer-size=4 -m64 -mtune=generic -fPIC'
--disable-stripping
  libavutil      52. 18.100 / 52. 18.100
  libavcodec     54. 92.100 / 54. 92.100
  libavformat    54. 63.104 / 54. 63.104
  libavdevice    54.  3.103 / 54.  3.103
  libavfilter     3. 42.103 /  3. 42.103
  libswscale      2.  2.100 /  2.  2.100
  libswresample   0. 17.102 /  0. 17.102
  libpostproc    52.  2.100 / 52.  2.100
[rtsp @ 0x1505480] Estimating duration from bitrate, this may be inaccurate
Input #0, rtsp, from 'rtsp://172.20.20.15/live/mpeg4_ulaw/HD720P':
  Metadata:
    title           : RTSP server
  Duration: N/A, start: 0.000000, bitrate: 64 kb/s
    Stream #0:0: Video: mpeg4, yuv420p, 1280x720 [SAR 1:1 DAR 16:9], 20
tbr, 90k tbn, 20 tbc
    Stream #0:1: Audio: pcm_mulaw, 8000 Hz, 1 channels, s16, 64 kb/s



The result vdo file is playable, just that audio is only available for 25
seconds. Seems like ffmpeg wrongly detect the duration and stop recording
after 25 seconds.

Any suggestion are welcome.

Best Regards,


Somsak

somsaks at gmail.com