I'd like to import in KDEnlive (but I'm also interested by other open source softwares) a video with transparency. The goal is to compress a sequence of png with transparency (produced by Natron) that takes a lot of space (for instance, one 10mn shot is turned into a 16Go large image sequence).
I tried to convert my sequence of image in ProRes using:
ffmpeg -framerate 29.97 -pattern_type glob -i '*.png' -c:v prores_ks -an our_result.mov
but it turns out that the video just has a black background in KDEnlive instead of a transparent one (it's strange also, because there is a large visible band around my image that is supposed to be transparent in the png, a bit like if my png was not premultiplied during the conversion). But I don't know if the problem comes from the conversion process, from the format used, from the fact that I need to enable something special in KDEnlive, or if KDEnlive just don't know how to deal with transparent video format.
Any idea? If KDEnlive can't deal with transparent videos, maybe you have another software to recommend?
-- EDIT --
I found out that the codev Quicktime Animation/RLE (
-c:v qtrle) works in KDEnlive. But now I need to find the options to compress it, right now the files is actually bigger than the png ^^')
-- EDIT 2 --
It turns out that vp9 (
-c:v libvpx-vp9 yourfile.webm) codec also works (it does compress quite well, but it's quite a slow process)