Loop a video overlay with ffmpeg

The loop option in the movie filter does not set new timestamps for the looped extension, so that has to be done manually.

ffmpeg -i "main_video" -af "pan=stereo|c0=FL|c1=FR,volume=1.5" \
    -vf "movie=video_bg_overlay.mp4:loop=0,setpts=N/FRAME_RATE/TB,hue=s=0[bg];[in]scale=iw/2:-1,pad=iw+20:ih+20:10:10:color=yellow[m]; [bg][m]overlay=shortest=1:x=(W-w)/2:y=(H-h)/2[out]" \
    -c:v libx264 Out_video