Here’s my solution to WebP:

#/bin/bash
# -----------------------------------------------------------------------------
# FILE PURPOSE AND NOTES:
# Convert webp files to png in current directory
#
# -----------------------------------------------------------------------------

echo "Convert Webp to Png"
echo
echo "Note this only works on webp files in the current directory:"
echo "Right now, that is $(pwd)"
echo
read -p "Press any key to continue"
echo

for i in *.webp; do
  echo ".. Converting $i"
  ffmpeg -hide_banner -loglevel error -i "$i" "${i%%.*}.png"
done

echo
echo "Here are the original webp and new png files now:"
echo
ls *.webp *.png
echo
echo "Ok to delete the webp files now? (Y/n)"
read -p ": " ANSWER
echo
case $ANSWER in
  n|N)
    echo "Leaving webp files."
    ;;
  *)
    echo "Removing webp files.."
    rm -v *.webp
    ;;
esac
echo