I've been trying to convert a video encoded in ProRes 4444HQ to webm vp9. I created an example video with a 50% transparent square in it. It should look like this:
but it looks like this:
Here is how I'm converting the video:
ffmpeg -i square.mov -c:v libvpx-vp9 -b:v 0 -crf 31 square.webm
I've tried changing color spaces and choosing different profiles but I can't seem to get rid of the grey shadow. Does it have something to do with the conversion from yuva to rgba?
ffplay original.mov -vf scale=alphablend=checkerboard,format=yuv420p
andffplay -vcodec libvpx-vp9 -i square.webm -vf scale=alphablend=checkerboard,format=yuv420p
– Gyanffmpeg -i square.mov -vf premultiply=inplace=1 -c:v libvpx-vp9 -b:v 0 -crf 31 square-premult.webm
– Gyan