[FFmpeg-trac] #481(avcodec:new): mpeg4 codec encoding bitrate (-b) is not honored

FFmpeg trac at avcodec.org
Sat Sep 17 05:05:34 CEST 2011

#481: mpeg4 codec encoding bitrate (-b) is not honored
             Reporter:  gyohng       |                     Type:  defect
               Status:  new          |                 Priority:  important
            Component:  avcodec      |                  Version:  git
             Keywords:  mpeg4        |               Blocked By:
  bitrate                            |  Reproduced by developer:  0
             Blocking:               |
Analyzed by developer:  0            |
 Please check this example:

 The example .bat file is for Windows, but it should equally work under
 Linux. This is tested on Sep 15 snapshot of the GIT.

 Running the command as such:
  * ffmpeg -i video-2011-09-07-12-02-58.mp4 -b 18000k -an a.avi

 Does not honor 18M bit rate, and instead encodes the file with 3-4Mbps bit
 rate with q constantly equal to 31.

 Also, -qmin/-qmax spec is not honored, and if qmin/qmax is specified to,
 for example, 2-8, q still stays at 31.0

 qscale is the only thing that works fine.

 Jul 31 2010 doesn't seem to have this problem and encodes everything

Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/481>
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