Batch convert videos into MP4 format using HandBrakeCLI

brake.rb

#!/usr/bin/env ruby
require 'optparse'

# Default options
options = {
  verbose: false,
  preset: "Fast 1080p30"
}

OptionParser.new do |opt|
  opt.banner = "Usage: brake.rb [sourcedir] [destination] \n" \
  "    brake.rb SOURCEFILE [sourcefile ...] [destination] \n" \
  'Options: '

  opt.on('-v', '--verbose', 'Run HandBrake in verbose mode (default: false)') do |v|
    options[:verbose] = v
  end

  opt.on('-p', '--preset PRESET', 'Set the HandBrake preset by name (default: Fast 1080p30)') do |p|
    options[:preset] = p
  end

  opt.parse!
end

args = ARGV.dup

# Without args, use the current directory as an implicit source directory
if args.empty?
  movies_dir = Dir.pwd
else # Try treating the first argument as a source dir if it's a directory
  movies_dir = File.expand_path(args.shift) if args.first && File.directory?(args.first)
end

# If we have a directory source
if movies_dir
  # Search for mp4, avi, and mkv files in the directory
  movies_glob = File.join(movies_dir, '**/*.{mp4,avi,mkv,dvdmedia}')
  files = Dir[movies_glob]
  puts "Converting files matching pattern\n  #{movies_glob}"
  puts
  abort "No files to convert!" if files.empty?
end

# If the last argument left is a directory, it's the destination
if args.last && File.directory?(args.last)
  dest_dir = File.expand_path(args.pop)
else # Default to the source dir or the current directory
  dest_dir = movies_dir || Dir.pwd
end
abort "Destination directory '#{dest_dir}' does not exist!" unless File.exist?(dest_dir)

# With a dest dir but no source dir, treat remaining args as source files
files ||= args
files.each do |path|
  abort "Source file '#{path}' does not exist!" unless File.exist?(path)
end

# Explain what we're about to do
files_count = "#{files.size} file#{'s' unless files.size == 1}"
puts "Converting #{files_count} into"
puts "  #{dest_dir}"
puts "  with preset '#{options[:preset]}'"
puts

# Convert each file
files.each do |file|
  new_file  = File.basename(file, File.extname(file)) + "-handbraked.mp4"
  dest_file = File.join(dest_dir, new_file)

  if File.exist?(dest_file)
    STDERR.puts "Converted file already exists!\n  #{dest_file}"
    next
  else
    puts "Converting #{File.basename(dest_file)}"
  end

  cmd = ["HandBrakeCLI"]
  cmd << "-v" if options[:verbose]
  cmd << '-i' << file
  cmd << '-o' << dest_file
  cmd << '--preset' << options[:preset]

  puts cmd.map {|arg| arg =~ /\s/ ? %{"#{arg}"} : arg }.join(" ")
  system(*cmd)
end

puts 'Done!'

If you don't have HandBrakeCLI installed, brew install handbrake.