[FFmpeg-user] Converting a video to a set of images from specific frames while cropping each frame differently

[Michael Koch]

Am 05.06.2023 um 00:35 schrieb Matt Groth:
> 2) Am I facing an XY issue? Is there a more elegant/performant way to apply a separate crop per frame (while excluding some frames altogether) when there are thousands of such frames per video?

The crop filter supports commands. That means you can write all the x 
and y values in a file and the use sendcmd to send these values to the 
crop filter.
The problem is how to select the frames, because the select filter 
doesn't support commands. I have no idea for this part.

Michael