Finds all cbz and cbr files in a directory and converts all files inside to webp

do-the-webp.sh

#!/bin/sh

# do-the-webp.sh
# Author: Pedro Vanzella <pedro@pedrovanzella.com>
# Usage: do-the-webp.sh <dir>
# License: BSD
#
# Finds all cbz and cbr files in a directory and converts all files inside to
# webp with quality 80, which should yield a 30% compression with no noticeably
# loss of quality

do_the_webp() {
    for f in "$1"/*.jpg; do
        [ -e "$f" ] || continue
        b=${f%.*}
        echo "[Converting] $b"
        cwebp -q 80 "$f" -o "$b".webp > /dev/null 2>&1
        #convert "$f" -quality 80 -define webp:lossless=true "$b".webp
        rm "$f"
    done
}

process_dir() {
    cd "$1"
    for file in *; do
        [ -e "$file" ] || continue
        if [[ -d "$file" ]]
        then
            echo "Recursively visiting $file"
            process_dir "$file"
        fi
        echo ""
        base=${file##*/}
        echo "[Processing]" $base

        if [[ $base == *.cbr ]]
        then
            mkdir "$base"-unrard
            cd "$base"-unrard

            unrar e ../"$base"
            do_the_webp .

            cd ..
            bn=${base%.*}
            #rar a "$bn"-webp.cbr "$base"-unrard/*
            zip "$bn"-webp.cbz "$base"-unrard/*
            rm -rf "$base"-unrard
        fi

        if [[ $base == *.cbz ]]
        then
            #echo "unzip"
            mkdir "$base"-unzipd
            cd "$base"-unzipd

            unzip -j ../"$base"
            do_the_webp .

            cd ..
            bn=${base%.*}
            zip "$bn"-webp.cbz "$base"-unzipd/*
            rm -rf "$base"-unzipd
        fi

        # uncomment this to also delete the original files
        #rm "$file"
    done
}

process_dir $1