[Ffmpeg-devel] Transcode video

Stefan Baltus stefan
Mon Jan 30 18:30:37 CET 2006


Hi guys,

I'm trying to transcode a .3gp (with h.263/amr) to a .avi:

$ ./ffmpeg -i test.3gp -f avi -acodec pcm_alaw test.avi
ffmpeg version 0.4.9-pre1, build 4718, Copyright (c) 2000-2004 Fabrice Bellard
  built on Jan 30 2006 13:25:22, gcc: 3.4.3 (csl-sol210-3_4-branch+sol_rpath)
Input #0, mov,mp4,m4a,3gp, from 'test.3gp':
  Duration: 00:00:43.7, bitrate: 142 kb/s
  Stream #0.0: Video: h263, 176x144, 14.89 fps
  Stream #0.1: Audio: amr_nb, 8000 Hz, mono
File 'test.avi' already exists. Overwrite ? [y/N] y
Output #0, avi, to 'test.avi':
  Stream #0.0: Video: mpeg4, 176x144, 14.89 fps, q=2-31, 200 kb/s
  Stream #0.1: Audio: pcm_alaw, 8000 Hz, mono, 64 kb/s
Stream mapping:
  Stream #0.0 -> #0.0
  Stream #0.1 -> #0.1
Press [q] to stop encoding
frame=  325 q=3.1 Lsize=     955kB time=21.8 bitrate= 358.5kbits/s    
video:591kB audio:342kB global headers:0kB muxing overhead 2.310629%

That works. But the problem is, when played back, the video is twice
the speed. Audio is OK. Seems like the 15fps is somehow translated to 30fps.

I tried: -r 15, with same result.

Using the CVS version doesn't work at all:

$ ./ffmpeg -i test.3gp
FFmpeg version CVS, Copyright (c) 2000-2004 Fabrice Bellard
  configuration:  --enable-amr_nb 
  libavutil version: 49.0.0
  libavcodec version: 51.1.0
  libavformat version: 50.0.0
  built on Jan 30 2006 17:34:29, gcc: 3.4.2
test.3gp: could not find codec parameters

Can anybody enlighten me?

Regards,

Stefan
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