Convert webm movies to GIF

convert-webm-to-gif.bash

#!/bin/bash
main() {
        if [[ -z $1 ]];
        then
                printf "Input file required\n"
                exit 1
        else
                local inputfile="$1"
        fi

        if [[ -z $2 ]];
        then
                printf "Output file required\n"
                exit 1
        else
                local outputfile="$2"
        fi

        ffmpeg -i "$inputfile" -r 10 -f image2pipe -vcodec ppm - | convert -delay 5 -loop 0 - gif:- | convert -layers Optimize - "$outputfile"
}

main "$@"