I have a few videos with alpha channels that I will like to overlay on top of each other. It's possible to get working with the following command
ffmpeg -i back.mov -i front.mov -filter_complex overlay -c:v png output.mov
However if I add another video to this it no longer works
ffmpeg -i back.mov -i front.mov -i front2.mov -filter_complex overlay -c:v png output.mov
Does anyone know a way of getting this to work? or would I have to output the first 2 layers and then run the code again with a new layer?
I will have more than 3 layers so looking for the most efficient way.