I'm trying to superimpose a transparent video on another video. If the original video has a longer duration than the transparent video, then the transparent video should be looped until the end of the original video. I wrote the following operation, but the transparent video does not repeat. How can I change this ffmpeg command to make the overlay video loop?
-i preresult.mp4 -c:v libvpx-vp9 -i Overlay.webm -filter_complex ""loop=0,setpts=N/FRAME_RATE/TB[bg];[bg]overlay=shortest=1:x=(W-w)/2:y=(H-h)/2"" -preset ultrafast output.mp4