Bash script to make a gif from a section of a video using ffmpeg

giffer.sh

#!/bin/bash

scale=640

if [ -z "$1" ] || [ -z "$2" ] || [ -z "$3" ]
then
    echo "Arugments <start time> <duration> <file>"
fi

ffmpeg -ss "$1" -t "$2" -y -i "$3" -vf fps=24,scale="$scale":-1:flags=lanczos,palettegen palette.png
ffmpeg -ss "$1" -t "$2" -i "$3" -i palette.png -filter_complex "fps=24,scale="$scale":-1:flags=lanczos[x];[x][1:v]paletteuse" out.gif

rm palette.png