Convert video to gif using ffmpeg, written in fish

video2gif.fish

# Inspired from http://superuser.com/a/556031
function videotrim --description 'Trim video (filename) (fromtime) (totime) (scalepx) (outputname)' --argument filename fromtime totime scalepx outputname
    if not test -f "$filename"
        echo "File not exists."
        return 1
    else if not test -r "$filename"
        echo "File is not readable."
        return 1
    end
    if not test -n "$fromtime"
        echo "Starting time not provided."
        return 1
    end
    if not test -n "$totime"
        echo "Ending time not provided."
        return 1
    end
    set duration (math -s3 $totime - $fromtime)
    echo "duration" is $duration
    if not test -n "$scalepx"
        set scalepx 960
    end
    if not test -n "$outputname"
        set outputname $filename"_trimmed"
    end
    echo "$filename" with "$scalepx" output "$outputname"
    echo ffmpeg -ss "$fromtime" -i "$filename" -t "$duration" -filter:v "scale=$scalepx:-2" -map_metadata -1 -c:v libx264 -pix_fmt yuv420p -preset veryslow -crf 23 -an "$outputname".mp4
    command ffmpeg -ss $fromtime -i $filename -t $duration -filter:v "scale=$scalepx:-2" -map_metadata -1 -c:v libx264 -pix_fmt yuv420p -preset veryslow -crf 23 -an $outputname.mp4
end