its a bit of both
*TL;DR, go to bottom of post for fix*
Kusaba calls imagemagick as default, with no options but the needed ones,
the scrambling is with imagemagick and the way it handles some gifs,
(gifs are made from lots of still images, *moreyouknow*)
compressed gifs start with the first image, then on the next frame it contains only changed pixels, overlapped on the first image, then the third is overlapped on the second, that's on the first image, ETC
when it is thumbnailed, this kind of gifs mess up, often ending in scrambled gifs(*artifacts*, see attached image, the more a image moves, the more if fucks up)
with imagemagick, there is a way to fix this with a flag, although it will increase the time it takes to thumbnail the image,
the way this flag works is by making imagemagick draw the first frame, then for the second it draws the first and second(then saves it), then the third it uses the second from memory to be used, along with the third image, to produce another frame.
so with this flag, it will have to process every image 3 times.
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