[FFmpeg-user] Video in video not from start

[Cecil Westerhof]

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

> Cecil Westerhof via ffmpeg-user <ffmpeg-user at ffmpeg.org> writes:
>
>> 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. But I will use it like this for the moment then.
>> Thanks.
>
> At the moment I have:
>     ffmpeg -y                           \
>       -to 30        -i "${inputFile}"   \
>       -ss 11 -to 28 -i "${overlayFile}" \
>       -filter_complex "
>         [0:v][1:v] overlay=main_w-(overlay_w+10):10:
>         enable='between(t,8,25)'
>       "                                 \
>       -pix_fmt yuv420p                  \
>       -acodec libmp3lame                \
>       -vcodec libx264                   \
>       -preset veryfast                  \
>       -crf 26                           \
>       "${outputFile}"
>
> It works, but I have a question and found a problem.

…

> In my search to find this solution, I think I saw a method to scale
> the overlay file. But I cannot find it anymore. :'-(
> Am I mistaken, or is it possible? I would like to scale the overlay
> file to 640:-2.

I found the solution I think:
    ffmpeg -y                           \
      -to 30        -i "${inputFile}"   \
      -ss 11 -to 28 -i "${overlayFile}" \
      -filter_complex "
        [1:v]           scale=960:-2[scaled:v],
        [0:v][scaled:v] overlay=main_w-(overlay_w+10):10:
                        enable='between(t,8,25)'
      "                                 \
      -pix_fmt yuv420p                  \
      -acodec libmp3lame                \
      -vcodec libx264                   \
      -preset veryfast                  \
      -crf 26                           \
      "${outputFile}"

I needed another scale as I thought.

It looks like the end part of the overlay is not displayed correctly,
but I will look into that.

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