Convert all audio files within directory to MP3 (320) with FFMPEG

gistfile1.rb

#!/usr/bin/env ruby

CONVERT_COMMAND = "ffmpeg -i ':input' -vn -ar 44100 -ac 2 -ab 320 -f mp3 ':output'"

def is_audio?(filename)
  filename =~ /\.(wav|flac|aac)$/
end

def extract_name(filename)
  File.basename(filename, File.extname(filename))+".mp3"
end

def convert(filename, dir)
  p "Conveting #{File.basename(filename)}"
  inpath = File.expand_path(filename)
  outpath = File.join(dir, extract_name(filename))
  command = CONVERT_COMMAND.gsub(/(:\w+)/, {":input" => inpath, ":output" => outpath})
  if system(command)
    p "Success"
  else
    p "Failed("
  end 
end 

dir = ARGV[0]

raise "Dir not found!" unless File.directory?(dir)

Dir.chdir(dir)

target_dir = ARGV[1] || dir

if target_dir != dir 
  require 'fileutils'
  FileUtils.mkdir_p(target_dir)
  
  if target_dir !~ /^\//
    target_dir = File.join(File.expand_path(dir), target_dir)
  end
end

Dir["*"].each do |file|
  convert(file, target_dir) if is_audio?(file) 
end