[FFmpeg-user] join two video files portions

[Liam Condron-Farnos]

>It's ok also in more steps.
>It could be:
>1) determine actual duration of video file
>2) subtract 5sec from it and use it as a start position for -ss
>
>If needed I could use a c++ prog for it.


c++ would probably be overkill, you could just write it up in a bash/batch
script invoking ffprobe and ffmpeg.

Hint:
ffprobe input.mp4 2>&1 | sed -n '/Duration:/s/.*:
\([0-9]*:[0-9]*:[0-9]*\.[0-9]*\).*/\1/p'

...will get you the duration of a video, assuming your system has sed.
Actually working this into a script is off-topic for this mailing list, of
course.