How to have OpenCV built process use self-built ffmpeg?

[cudawarped]

See

Error: 'Your platform doesn't suppport hardware accelerated AV1 decoding.' when i use 'cv2.VideoCapture'

To build against FFmpeg and get AV1 decoding you need to: Build or dowload and extract a build of FFMpeg to <FFMPEG_BUILD>. I would suggest simply downloading from here and depending on your license requirements you will want to download either ffmpeg-n5.0.1-7-g7389a49fd3-win64-gpl-shared-5.0.zip or ffmpeg-n5.0.1-7-g7389a49fd3-win64-lgpl-shared-5.0.zip Create a cmake directory <FFMPEG_BUILD>/cmake. Save the cmake script (ffmpeg-config.cmake) mentioned in the below post to that directory…

Note: You may have to modify the CMake script if you use a more recent version of FFMpeg than I described there.