#!/bin/sh
rm img/*.gif
waitjobs() {
    while [ "$(jobs -p | wc -l)" -ge "$1" ]; do wait; done
}
for x in img/*.pam; do
    echo "$x"
    pamtogif -quiet "$x" > "$x.gif" &
    waitjobs "$(nproc)"
done
wait
gifsicle -d1 --verbose img/*.gif > anim.gif
ffmpeg -i anim.gif -filter:v "setpts=0.1*PTS,scale=iw*4:ih*4:flags=neighbor" -r 100 anim.webm