[FFmpeg-user] -vcodec copy encodes nothing (empty output file) with h264 input

[Paul]

ffmpeg -f video4linux2  -vcodec h264 -s 640x48 -r 15 -i /dev/video0 -vcodec 
copy  output.mkv
ffmpeg version 1.2 Copyright (c) 2000-2013 the FFmpeg developers
  built on May  7 2013 07:05:29 with gcc 4.7.1 (GCC)
  configuration: --enable-gpl --enable-libx264
  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
[video4linux2,v4l2 @ 0x93e05e0] The V4L2 driver changed the video from 640x48 
to 160x90
[video4linux2,v4l2 @ 0x93e05e0] Estimating duration from bitrate, this may be 
inaccurate
Input #0, video4linux2,v4l2, from '/dev/video0':                                                                                                                                    
  Duration: N/A, start: 52180.900978, bitrate: N/A
    Stream #0:0: Video: h264 (Constrained Baseline), yuvj420p, 160x90 [SAR 1:1 
DAR 16:9], -2 kb/s, 15 fps, 15 tbr, 1000k tbn, 30 tbc
File 'output.mkv' already exists. Overwrite ? [y/N] y
Output #0, matroska, to 'output.mkv':
  Metadata:
    encoder         : Lavf54.63.104
    Stream #0:0: Video: h264 (H264 / 0x34363248), yuvj420p, 160x90 [SAR 1:1 
DAR 16:9], q=2-31, -2 kb/s, 15 fps, 1k tbn, 1000k tbc
Stream mapping:
  Stream #0:0 -> #0:0 (copy)
Press [q] to stop, [?] for help
frame=    0 fps=0.0 q=-1.0 Lsize=       1kB time=00:00:00.00 bitrate=N/A    
video:0kB audio:0kB subtitle:0 global headers:0kB muxing overhead inf%
Output file is empty, nothing was encoded (check -ss / -t / -frames parameters 
if used)


On Monday, May 13, 2013 06:49:39 am Carl Eugen Hoyos wrote:
> Paul <paul <at> hivetool.org> writes:
> > Doesn't work. No data to output file:
> > 
> > ffmpeg -f video4linux2 -vcodec h264 -s 640x480
> > -r 15 -i /dev/video0 -vcodec copy output.mkv
> 
> Complete, uncut console output missing.
> 
> Carl Eugen
> 
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