It seems that the best way to convert to GIF is to use the exact dimensions of the original. In the
below case the original was 1112x980. As straight-up GIF was about 1.5MB. Using the smaller dimension,
0.6 of each each, blew up the file size to about 25MB. It's best to make the original video capture
smaller.


convoying
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$ ffmpeg -ss 00:00:01.000 -i muster_animation.mov -pix_fmt rgb24 -r 10 -s 1368x880   -t 00:00:44.000 muster_animation.gif