Gifsicle Speed Changer

delayspec.pl

use POSIX;
if($#ARGV == -1) { die "No speedup value specified!"; }
$speedup = shift(@ARGV);
while(<>) {
    if(/\+ image #(\d+)/) {
        $num = $1; 
    } elsif(/delay ([\d\.]+)s/) {
        $delay = POSIX::strtod($1);
        $delay /= $speedup;
        if($lastdelay && $lastdelay != $delay) {
            if(!$startnum) { $startnum = 0; }
            printf("-d%d #%d-%d ",POSIX::ceil($delay*10), $startnum, $num-1);
            $startnum = $num;
        }
        $lastdelay = $delay;
    }
}

speedup.sh

SPEEDUP=$1
INGIF=$2
OUTGIF=$3
gifsicle `gifsicle --info $INGIF | perl delayspec.pl $SPEEDUP` < $INGIF > $OUTGIF