Export an optimised GIF from an MP4

gifify.sh

#!/bin/sh

if [[ ${1:(-4)} != ".mp4" ]]; then
    echo "Invalid input file $1"
    exit 1
fi

palette="${1%.*}-palette.png"

filters="fps=25,scale=320:-1:flags=lanczos"

gif=${1%.*}.gif

echo "Converting $1 to $gif" 

ffmpeg -v warning -i $1 -vf "$filters,palettegen" -y $palette
ffmpeg -v warning -i $1 -i $palette -lavfi "$filters [x]; [x][1:v] paletteuse" -y $gif

rm $palette