gifmake.sh

#!/bin/bash -x
# Based on http://blog.pkh.me/p/21-high-quality-gif-with-ffmpeg.html
echo "for options see"
echo "http://blog.pkh.me/p/21-high-quality-gif-with-ffmpeg.html"

if [ $# -ne 4 ]; then
    echo "$0 <file> <name> <start_00:00:00> DURATION"
    exit
fi
FILE="$1"
NAME="$2"
START="$3"
END="$4"

palette="/tmp/palette.png"

GenOptFavorMovement="=stats_mode=diff"
UseOptNoDither="=dither=none"
#filters="fps=15,scale=320:-1:flags=lanczos"
#filters="fps=10"

#filters="fps=10,scale=320:-1:flags=lanczos"
filters="fps=10,scale=640:-1:flags=lanczos"
filters="fps=6,scale=320:-1:flags=lanczos"
filters="fps=6,scale=640:-1:flags=lanczos"
#fast="setpts=0.38*PTS,"
#NOGOOD: filters="fps=10,scale=160:-1:flags=lanczos,$optnodither"

#ffmpeg -v warning \
#       -i ${FILE} -ss $START -t $END -vf "$filters,palettegen" -y $palette
ffmpeg -ss $START -t $END -i ${FILE} -vf "$filters,palettegen$GenOptFavorMovement" -y $palette
ffmpeg -ss $START -t $END -i ${FILE} -i $palette -lavfi "$fast$filters [x]; [x][1:v] paletteuse$UseOptNoDither" -y ${NAME}.gif

#ffmpeg -i ${FILE} -ss $START -t $END -r 10 -vf scale=600:-1 ${NAME}.gif


##
echo try
echo gifsicle -O3 --lossy=80  $NAME.gif --output ${NAME}_compressed80.gif
echo gifsicle -O3 --lossy=140  $NAME.gif --output ${NAME}_compressed140.gif
echo gifsicle -O3 --lossy=200  $NAME.gif --output ${NAME}_compressed20.gif
echo lossy flag requires https://kornel.ski/lossygif extension