hardsub two subtitle file in one avi

hardsub.rb

#!/usr/bin/env ruby

require "rubygems"
require "pry"

$DEBUG = false

def hardsub(source_file, sub_file, sub_encoding, position, result_file)
	command =  %Q{ mencoder -oac mp3lame -ovc lavc -lavcopts vcodec=mpeg4:vbitrate=2000 #{source_file} \
	-subwidth 75 -subcp #{sub_encoding} -subfont-text-scale 3 -sub #{sub_file} \
	-o #{result_file} -subpos #{position}}

	command += ' > /dev/null' unless $DEBUG

	puts "[DEBUG] run command: #{command}" if $DEBUG

	result = system(command)

	raise '[ERROR] command failed' if (!result || $?.to_i > 0)
end

def hardsub_top_and_bottom(source_file, top_sub_file, bottom_sub_file, sub_encoding, result_path)
	file_name = 'hardsub_' + File.basename(source_file)
	result_path = File.dirname(source_file) unless result_path
	top_file = File.join('/', 'tmp', file_name)

	hardsub(source_file, top_sub_file, sub_encoding, 0, top_file)
	hardsub(top_file, bottom_sub_file, sub_encoding, 100, File.join(result_path, file_name))
end

def hardsub_all_files_from_folders(video_folder, top_sub_folder, bottom_sub_folder, result_folder = nil, sub_encoding = 'cp1251')
	result_folder = video_folder unless result_folder
	
	Dir[File.join(video_folder, '*.avi')].each do |video_file|
		filename = File.basename(video_file).gsub(File.extname(video_file), '.srt')
		top_sub_file = File.join(top_sub_folder, filename)
		bottom_sub_file = File.join(bottom_sub_folder, filename)

		if !File.exist?(top_sub_file) || !File.exist?(bottom_sub_file)
			raise "[ERROR] Can't fine subtitle #{top_sub_file} or #{top_sub_file}"
		end

		puts "[INFO] hardsub file #{video_file} with top sub #{top_sub_file} and bottom sub #{bottom_sub_file} to #{result_folder} with encoding #{sub_encoding}"

		hardsub_top_and_bottom(
			video_file, 
			top_sub_file, 
			bottom_sub_file, 
			sub_encoding, 
			result_folder
		)
	end
end

if ARGV.length < 3
  puts "Dude, not the right number of arguments."
  puts "Usage: ruby hardsub.rb path/to/video/files path/to/top_sub/files path/to/bottom_sub/files [path/to/result/files] [sub_encoding]"
  exit
else
	hardsub_all_files_from_folders(*ARGV)
end