How to fix fps/duration information in MJPEG File

Question

I have a set of MJPEG .avi files which were logged as being at 25fps, but were actually recorded slightly slower than this, so they're timing is wrong (they show up as being about 2 minutes shorter than the actual recording). I know the true duration of recording - how can I set the duration of the file to that, without re-encoding?

Answer 1

You may use FFmpeg, using the same solution posted here.

The following two steps solution is without re-encoding:

• Convert from AVI to raw MJPEG:

   ffmpeg -i input.avi -c copy input.mjpeg
  

• Remux the raw MJPEG with new framerate (24 fps for example):

   ffmpeg -r 24 -i input.mjpeg -c copy output.avi
  

The above solution assumes there is no audio stream.