[FFmpeg-user] Hi, I want ask a quesiton about -vcodec copy, mine doesn't work correct, thanks.

[Wei Gao]

Hi, I have a mp4 video, and when I use command :
 ffmpeg -i ./testfile/wwwq.mp4 -vcodec libx264  ./testfile/out.h264, ffmpeg
works fine. but I want to get the h264 stream in the file using -vcodec
copy, the command is as follows:

ffmpeg -i ./testfile/wwwq.mp4 -vcodec copy  ./testfile/out.h264, ffmpeg
print that

Output file is empty, nothing was encoded (check -ss / -t / -frames
parameters if used)

the whole output print is as follows, no error report in output print:

$ ffmpeg -i ./testfile/wwwq.mp4 -vcodec copy  ./testfile/out.h264
ffmpeg version 1.1.git Copyright (c) 2000-2013 the FFmpeg developers
  built on May  3 2013 14:44:20 with gcc 4.6.2 (GCC)
  configuration: --disable-debug --enable-gpl --enable-avfilter
--enable-libx264 --enable-opencl --enable-pthreads
  libavutil      52. 27.101 / 52. 27.101
  libavcodec     55.  6.100 / 55.  6.100
  libavformat    55.  4.100 / 55.  4.100
  libavdevice    55.  0.100 / 55.  0.100
  libavfilter     3. 62.100 /  3. 62.100
  libswscale      2.  2.100 /  2.  2.100
  libswresample   0. 17.102 /  0. 17.102
  libpostproc    52.  3.100 / 52.  3.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from './testfile/wwwq.mp4':
  Metadata:
    major_brand     : mp42
    minor_version   : 1
    compatible_brands: mp42isom
    creation_time   : 2013-09-16 20:38:44
  Duration: 00:00:14.58, start: 0.000000, bitrate: 4115 kb/s
    Stream #0:0(eng): Video: h264 (Main) (avc1 / 0x31637661), yuv420p,
1280x720 [SAR 3:4 DAR 4:3], 4019 kb/s, 29.97 fps, 29.97 tbr, 90k tbn, 59.94
tbc
    Metadata:
      creation_time   : 2013-09-16 20:38:44
      handler_name    : AVID Video Handler
    Stream #0:1(eng): Audio: aac (mp4a / 0x6134706D), 48000 Hz, stereo,
fltp, 88 kb/s
    Metadata:
      creation_time   : 2013-09-16 20:38:44
      handler_name    : AVID Audio Handler
    Stream #0:2(eng): Data: none (mp4s / 0x7334706D), 12960 kb/s
    Metadata:
      handler_name    : AVID Object Descriptor Handler
    Stream #0:3(eng): Data: none (mp4s / 0x7334706D), 11520 kb/s
    Metadata:
      handler_name    : AVID BIFS Handler
File './testfile/out.h264' already exists. Overwrite ? [y/N] y
Output #0, h264, to './testfile/out.h264':
  Metadata:
    major_brand     : mp42
    minor_version   : 1
    compatible_brands: mp42isom
    encoder         : Lavf55.4.100
    Stream #0:0(eng): Video: h264 (avc1 / 0x31637661), yuv420p, 1280x720
[SAR 3:4 DAR 4:3], q=2-31, 4019 kb/s, 29.97 fps, 90k tbn, 29.97 tbc
    Metadata:
      creation_time   : 2013-09-16 20:38:44
      handler_name    : AVID Video Handler
Stream mapping:
  Stream #0:0 -> #0:0 (copy)
Press [q] to stop, [?] for help
frame=    0 fps=0.0 q=-1.0 Lsize=       0kB time=00:00:00.00 bitrate=N/A
video:0kB audio:0kB subtitle:0 global headers:0kB muxing overhead nan%
Output file is empty, nothing was encoded (check -ss / -t / -frames
parameters if used)

I use the latest version which download from
http://ffmpeg.zeranoe.com/builds/, can someone give any help?

Thanks
Best regards