[FFmpeg-user] Removing part of a video

[Cecil Westerhof]

Cecil Westerhof via ffmpeg-user <ffmpeg-user at ffmpeg.org> writes:

> I need to cut a part out of a video. (A certain speaker does not want
> to be published.)
> Searching on the internet I found this:
>     Following is a snippet we used to remove a few seconds from a video using ffmpeg
>
>     ffmpeg -i 'input.mkv' -filter_complex \
>       "[0:v]trim=end=553,setpts=N/FRAME_RATE/TB[v0]; \
>        [0:a]atrim=end=553,asetpts=N/SR/TB[a0]; \
>        [0:v]trim=start=559,setpts=N/FRAME_RATE/TB[v1]; \
>        [0:a]atrim=start=559,asetpts=N/SR/TB[a1]; \
>        [v0][a0][v1][a1]concat=n=2:v=1:a=1[v][a]" \
>       -map "[v]" -map "[a]" 'output.mkv'
>
>     Specifically, we removed the seconds 09:13 (second 553) to 09:19 (second 559).
>
> Is this the correct way to do it (after setting the correct
> timestamps), or is there a better way?

It works, but there are a few problems. :'-(

I cut 1:50 from a video of 18:51 to get a video to get a video of
17:01.
The video goes from 402.4 MB to 341.8 MB.
But the problem is that ffmpeg takes all my CPU and the speed is
0.359. It would be nice if there would be a more efficient option.
What is also not nice is that the chapter info is not updated.
But that is preventable: I could do first the cut and afterwards
create the chapters. I would prefer the other way around, but I can
life with that.

-- 
Cecil Westerhof
Senior Software Engineer
LinkedIn: http://www.linkedin.com/in/cecilwesterhof