[FFmpeg-trac] #2108(undetermined:closed): empty frame add the end of the video

FFmpeg trac at avcodec.org
Wed Jan 9 09:56:48 CET 2013


#2108: empty frame add the end of the video
-------------------------------------+-------------------------------------
             Reporter:  ben          |                    Owner:
                 Type:  defect       |                   Status:  closed
             Priority:  normal       |                Component:
              Version:  unspecified  |  undetermined
             Keywords:  h264 mov     |               Resolution:  invalid
             Blocking:               |               Blocked By:
Analyzed by developer:  0            |  Reproduced by developer:  0
-------------------------------------+-------------------------------------
Changes (by cehoyos):

 * keywords:  h264 => h264 mov
 * status:  new => closed
 * resolution:   => invalid


Comment:

 Replying to [comment:8 ben]:
 > I thought it was 2:85 because ffmpeg -i myinput.mp4 says:
 > Duration: 00:00:02.85,

 Afair, this is an informational value stored in the header of the file.

 > start: 0.013333, bitrate: 1039 kb/s
 >
 > now I'm not sure what those two values means. and also why is 29.98 fps
 getting changed to 30 fps after re-encoding?
 > shouldn't it stay the same?

 Without testing, I assume the original file is vfr (variable frame rate)
 which is not supported by the FFmpeg mov muxer, it has to choose a
 framerate.
 Since no frames get dropped or duplicated (this would be visible in
 ffmpeg's output), the framechoice seems to be ok. You can add -r
 30000/1001 to your command line if you prefer. Also consider testing a
 longer sample to see if frames will be dropped / duplicated with one of
 the choices.

 Please reopen if you encounter A/V desync (or similar problems), the fact
 that the duration in the mov header does not exactly match the output file
 is no bug imo.

-- 
Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/2108#comment:9>
FFmpeg <http://ffmpeg.org>
FFmpeg issue tracker


More information about the FFmpeg-trac mailing list