[FFmpeg-user] Video in video not from start

[Cecil Westerhof]

Michael Koch <astroelectronic at t-online.de> writes:

> Am 05.01.2024 um 10:26 schrieb Cecil Westerhof via ffmpeg-user:
>> Ferdi Scholten <ferdi at sttc-nlp.nl> writes:
>>
>>> I want to play a video in a video from a certain point. I understood I
>>>> could do something like:
>>>>       ffmpeg              \
>>>>         -i input1.mp4     \
>>>>         -i input2.mp4     \
>>>>         -filter_complex "
>>>>           [0:v][1:v] overlay=25:25:
>>>>           enable='between(t,8,20)'
>>>>         "                 \
>>>>         -pix_fmt yuv420p  \
>>>>         -c:a copy         \
>>>>         output.mp4
>>>>
>>>> But this starts input2.mp4 from the start of input2.mp4 on the 8
>>>> second, for twelve seconds.
>>>> Is it possible to let input2.mp4 not start from second 0, but from
>>>> second 17?
>>>>
>>> Try putting -ss 17 between the two inputs.
>> I was thinking about that. But that means that if I want to use
>> input2.mp4 several times, I should use input2.mp4 several times with
>> the correct -ss. Not really a problem, but I had hoped for a more
>> efficient way.
>
> You can cut off the beginning of the second stream with the "trim"
> filter, but then you must also use the "atrim" filter for audio. "-ss"
> is easier, but can only make a cut at a keyframe, if I remember right.

For the moment being I will keep at -ss, but I will look into it
later.

I do have a little problem with the functionality. I make it a bit
more clear and start a new thread about it.

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