Comment by throw_m239339

Does anybody know how to overlay a shorter footage on a longer one? Because the shortest footage just freeze at the last frame in the tutorial. I want the shorter overlaid footage to loop on top of the longer one, Here is what I've tried:

    ffmpeg -i "Old Film Grain.mp4"  -i "main-footage.mp4"  -filter_complex \ 
    "[0]format=rgba,colorchannelmixer=aa=0.25[fg];[1][fg]overlay[out]"\ 
    -map [out] -pix_fmt yuv420p -crf 18 final.mp4

The shortest footage (Old Film Grain.mp4) doesn't loop as an overlay.