I am currently creating a webm file using two mp4's (alpha - black background, white silthoette) and normal video.
Using following ffmpeg command:
ffmpeg -i color.mp4 -i alpha.mp4 \
-filter_complex [0][1]alphamerge,format=yuva420p \
-c:v libvpx -strict -2 -auto-alt-ref 0 \
output.webm
And while this works fine for most browsers, it doesn't work on iOS, so I need to create a .mov (or maybe something else?) file with transparent background.
What is the proper way to do it in ffmpeg?