[FFmpeg-user] extract frames every n frames

[Carl Eugen Hoyos]

2019-04-26 22:02 GMT+02:00, francesco piasentini
<francescopiasentini at gmail.com>:
> Is working fine.
> I'm working on a video that's a basically a slideshow of images morphing
> through different steps.
> frame 1: step 1
> frame +8: step 2
> +7 frames: step 3
> +6: step 4
> +8: step 5
> ..
> +7: step n
>
> So the number of frames between animation steps is variable, randomly, with
> a media of 7.
> If I put: "pick a frame every 7", the resulting extracted frames are
> "jagged", with non-uniform morphing between them.
> As you may imagine, I have no experience on codec and video in general.
>
> Is there any filter that fly through frames and extract only a frame if
> it's different from the previous?

Try the scene option of the select filter:
select=gt(scene,0.4)
https://ffmpeg.org/ffmpeg-filters.html#select_002c-aselect

Please avoid top-posting here, Carl Eugen