[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:
http://pvtftp.trueinstruments.com/ffmpeg_bug.zip
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
correctly.
--
Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/481>
FFmpeg <http://ffmpeg.org>
FFmpeg issue tracker
More information about the FFmpeg-trac
mailing list