Transcode FLAC to MP3

Rakefile

require 'find'

VERBOSE = false

mp3_files = []

Find.find('.') do |f|
    if File.extname(f) == '.flac'
        flac = f
        mp3 = "../Music/#{File.dirname(flac)}/#{File.basename(flac, '.flac')}.mp3"
        mp3_files.push(mp3)
        file mp3 => flac do
            puts "#{mp3}"

            if VERBOSE
                loglevel = 'info'
            else
                loglevel = 'panic'
            end

            FileUtils.mkdir_p("../Music/#{File.dirname(flac)}")

            # Write to a temporary file
            suffix = ('a'..'z').to_a.shuffle[0,8].join
            tmp = "../Music/#{File.dirname(flac)}/.#{File.basename(flac, '.flac')}.mp3.#{suffix}~"
            sh 'ffmpeg',
                '-hide_banner', '-loglevel', loglevel,
                '-y',
                '-i', flac,
                '-codec:a', 'libmp3lame', '-qscale:a', '2',
                '-f', 'mp3',
                tmp, verbose: VERBOSE

            # Delete the MP3 file
            File.delete(mp3) if File.exist?(mp3)

            # Rename temp to MP3
            File.rename(tmp, mp3)
        end
    end
end

# Note: you can clean up the temp files with
# find ../Music/ -type f -name '.*~' -delete

multitask :transcode => mp3_files

art_files = []

Find.find('.') do |f|
    if File.extname(f) == '.jpg'
        src = f
        dst = "../Music/#{File.dirname(src)}/#{File.basename(src)}"
        art_files.push(dst)

        file dst => src do
            FileUtils.copy(src, dst)
        end
    end
end

multitask :artwork => art_files

task :default => [:transcode, :artwork]