need this feature so badly
Animated Portable Network Graphics (APNG (https://en.wikipedia.org/wiki/APNG)) file format
bump
If you need to apply video filters, this adds an additional re-encoding step, diminishing quality, but once you have a video clip in another format ready, do
ffmpeg -i your-video-clip -c apng your-video-clip-as-apng.png
and in case "your-video-clip" was encoded with h264, you'll inflate the original file size 50x or more ;)