m4a2mp3

#!/usr/bin/env ruby

$stdin.each_line do |line|
  path = line.chomp

  base = File.basename(path, '.m4a')
  name = File.join(File.dirname(path), "#{base}.mp3")

  next if File.exists?(name)
  cmd = %(ffmpeg -i "#{path}" -acodec libmp3lame -ab 160k "#{name}" < /dev/null)

  puts cmd
  puts system(cmd) rescue nil
end