Adjust the time stamps of the subtitles (srt) file

adjust_time_stamp.rb

require 'pp'
require 'time'

class Item 
	attr_accessor :index, :start_time, :end_time, :text

	def initialize(list)
		@index = list[0]
		@start_time, @end_time = list[1].split(' --> ').map{|a1| Time.parse(a1)}
		@text  = list[2..-1].join(' ')
	end

	# d in seconds, can be a negative value
	def adjust(d)
		@start_time = @start_time + d
		@end_time   = @end_time   + d
	end

	def info
		ret = "#{@index}\n"
		ret += "#{@start_time.strftime("%H:%M:%S,%L")} --> #{@end_time.strftime("%H:%M:%S,%L")}\n"
		ret += "#{@text}\n\n"
	end
end

class Subtitles
	attr_accessor :data

	def initialize(filename)
		@data = []
		parse_file(filename)
	end

	def parse_file(filename)
		tmp = File.open(filename).read.split("\n\n")
		tmp.each {|t| @data << Item.new(t.split("\n"))}
	end
	
	def adjust_time_stamps
		@data.each do |d|
			d.adjust(-8.1)
		end
	end
	
	def output(filename)
		fp = File.open(filename, "w")
		@data.each do |d|
			fp.write(d.info)
		end
		fp.close
	end

end

b = Subtitles.new('Wrong.In.Time.2011.srt')
b.adjust_time_stamps
b.output('In.Time.2011.srt')