video2gif.sh

#!/bin/bash

set -e

if [[ -z "$1" ]]; then
    echo "please enter file"
    exit 1
fi

filename=$(basename -- "$1")
filename="${filename%.*}"
echo "filename:$filename"

read -p 'Scale (480): ' scale
if [[ -z $scale ]]; then
    scale=480
fi

read -p 'FPS (20):' fps
if [[ -z $fps ]]; then
    fps=20
fi

ffmpeg -y -i "$1" -vf fps=$fps,scale=$scale:-1:flags=lanczos,palettegen palette.png
ffmpeg -y -i "$1" -i palette.png -filter_complex "fps=$fps,scale=$scale:-1:flags=lanczos[x];[x][1:v]paletteuse" temp.gif
gifsicle -O3 temp.gif -o "$filename.gif"

rm -f palette.png
rm -f temp.gif