When I converted the video, it had a green background. It's caused due to the transparent layer not having a color. Ironically this would be great if this was an over layer on top of another video, but it's just green on it's own. The way to fix this issue is to drop the transparent images on top of a black background in a graphics editor and save each one of them. Then convert that to a video. Video's can't be transparent. As for the final command, it would be something like;
Code:
ffmpeg -f image2 -framerate 40 -i "Alice_Dance_%1d.png" -vcodec h264 -crf 18 "Alice_Dance.mp4"
You could automate the first part, putting the black background on each png file but I'm not to great at that automation on command line. I'd use C# since I'm better with that. I bet ImageMagick could do it. Ultimately it's probably just better to use them as apng files. I may go ahead and do the video thing once I have a bit more time.
That said, this is a very technical post in a game thread.