[FFmpeg-user] Duplication of time stamps when concatenating .mkv files

[Stefano Sabatini]

On date Tuesday 2015-02-03 13:16:00 -0800, Luke Paone wrote:
> Hi,
> 
> I am running into some issues when splitting and then concatenating files
> using ffmpeg.
> 
> I am using the following command line to split the files:
> 
> ffmpeg -i D:\Videos\SwP\sp.webm -codec copy -f segment -segment_time 22
> -reset_timestamps 1 D:\Videos\SplitTest\swp_%04d.webm
> 
> and the output is:
[...] 
> My issue is that after the merge, the duration of the video is shorter than
> the original file by 7 frames, which is the number of merges that happened
> between the 8 files that came out after the split. I used mkvinfo to look
> at the details of the .webm file and found that the problem is that ffmpeg
> is giving the first frame of the second part of a merged video the same
> time stamp as the last frame of the first part. Therefore I have duplicate
> time stamps at the point of every merge and I end up loosing a frame
> because of it.
[...]
> Has anyone run into this issue before? Am I missing something? I tried
> looking on the forums and in the ffmpeg trac for a bug but was unable to
> find anything. Any help here would be appreciated.

Did you try to use the reset_timestamps segment option?