wplace ffmpeg converter

#!/bin/bash
# none, sierra2, burkes or steinberg look good in dithering


#Files/args
inputFile="${1}"
ditherType="${2:-sierra2}"


#print usage
if [ -z "$inputFile" ]; then
    echo "Usage: wpConvert.sh [input] [dither]"
    echo "Dither options: none, bayer, floyd_steinberg, sierra2, sierra2_4a, sierra3, atkinson, burkes"
    exit 1
fi


inputBaseName=$(basename "$inputFile")
inputFileName="${inputBaseName%.*}"
outputFile="./wplace_${inputFileName}.png"


#wplace palette as png encoded in base64
paletteBase64="iVBORw0KGgoAAAANSUhEUgAAABAAAAAQCAMAAAAoLQ9TAAAAwFBMVEUAAAAAAAAMgW4PeZ8PuWgQrqYT4b4T5nsoUJ4zOUE8PDxAk+RKQoRKazpNMbhalEpgABhg9/JoRjRrUPZtZD9tdY14DJl4eHh6ccR7Y1J9x/+ExXOH/16UjGuVaCqZsfubUkmchDGchGulDh6qOLmqqqqzudG1rvG7+vLFrTHLAHrNxZ7RgFHRgHjS0tLWtZTbpGPgn/nkXBro1F/sH4DtHCTzjan2qgn4snf53Tv6gHL6tqT/fyf/xaX/+rz///+JnjTCAAAAAXRSTlMAQObYZgAAABtJREFUGJVjYUQDLAKkCjCw8DGgAhaGoSpwEACVZwF8B2PFYwAAAABJRU5ErkJggg=="


#paletteuse
ffmpeg -y -i "${inputFile}" \
    -i <(printf '%s' "$paletteBase64" | base64 --decode) \
    -filter_complex "[0:v][1:v] paletteuse=dither=${ditherType}:alpha_threshold=128,format=rgba" \
    -update true "${outputFile}"