src/websites/redtube.rb

   1 #
   2 # Copyright Michael Orlitzky
   3 #
   4 # http://michael.orlitzky.com/
   5 #
   6 # This program is free software: you can redistribute it and/or modify
   7 # it under the terms of the GNU General Public License as published by
   8 # the Free Software Foundation, either version 3 of the License, or
   9 # (at your option) any later version.
  10 #
  11 # This program is distributed in the hope that it will be useful,
  12 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  14 # GNU General Public License for more details.
  15 #
  16 # http://www.fsf.org/licensing/licenses/gpl.html
  17 #
  18 #
  19 # NOTE:
  20 #
  21 # All credit belongs to whomever reverse-engineered the Redtube
  22 # Flash applet in the first place. I took the algorithm from this
  23 # script:
  24 #
  25 # http://userscripts.org/scripts/review/8691
  26 #
  27 # and merely cleaned it up a bit while porting it to Ruby.
  28 #
  29
  30 # The Redtube class needs the extra string methods..
  31 require 'src/string'
  32 require 'src/website'
  33
  34 # This class handles the algorithm magic needed to get
  35 # the URL from a Redtube video id.
  36 class Redtube < Website
  37
  38   VALID_REDTUBE_URL_REGEX = /^(http:\/\/)?(www\.)?redtube\.com\/(\d+)$/
  39
  40   def self.owns_url?(url)
  41     return url =~ VALID_REDTUBE_URL_REGEX
  42   end
  43
  44
  45   # The only public method. This calls the other parts
  46   # of the algorithm and, with any luck, we wind up with
  47   # the URL to the video.
  48   def get_video_url()
  49     # First, parse the video ID out of the URL.
  50     video_id = parse_video_id()
  51
  52     padded_id = video_id.to_s.pad_left('0', 7)
  53
  54     video_dir = self.get_video_dir(video_id)
  55     file_name = self.get_file_name(padded_id)
  56
  57     # This mess is actually the only directory out of
  58     # which they serve videos.
  59     return 'http://dl.redtube.com/_videos_t4vn23s9jc5498tgj49icfj4678/' +
  60            "#{video_dir}/#{file_name}"
  61   end
  62
  63
  64   protected
  65
  66   VIDEO_FILE_EXTENSION = '.flv'
  67
  68   def parse_video_id()
  69     return /\d+/.match(@url)[0]
  70   end
  71
  72
  73   # Not sure what they're thinking with this one.
  74   def get_video_dir(video_id)
  75     return (video_id.to_f / 1000.0).floor.to_s.pad_left('0', 7)
  76   end
  77
  78
  79   # The first part of the algorithmic magic. Multiply each
  80   # digit of the padded video id by the index of the
  81   # following digit, and sum them up.
  82   def int_magic(padded_video_id)
  83     ret = 0
  84
  85     0.upto(6) do |a|
  86       ret += padded_video_id[a,1].to_i * (a+1)
  87     end
  88
  89     return ret
  90   end
  91
  92
  93   # Part 2 of the magic. Sum the digits of the result
  94   # of the first magic.
  95   def more_magic(file_string)
  96     magic = self.int_magic(file_string).to_s
  97
  98     ret = 0
  99
 100     0.upto(magic.length - 1) do |a|
 101       ret += magic[a,1].to_i
 102     end
 103
 104     return ret
 105   end
 106
 107
 108   # Complete fricking mystery
 109   def get_file_name(file_string)
 110     map = ['R', '1', '5', '3', '4', '2', 'O', '7', 'K', '9', 'H', 'B', 'C', 'D', 'X', 'F', 'G', 'A', 'I', 'J', '8', 'L', 'M', 'Z', '6', 'P', 'Q', '0', 'S', 'T', 'U', 'V', 'W', 'E', 'Y', 'N']
 111
 112     # The stupid variable names I copied from the
 113     # source script. Considering myself disclaimed.
 114     my_int = self.more_magic(file_string)
 115     new_char = '0' + my_int.to_s
 116
 117     if my_int >= 10 then
 118       new_char = my_int.to_s
 119     end
 120
 121     file_name =  map[file_string[3] - 48 + my_int + 3]
 122     file_name += new_char[1,1]
 123     file_name += map[file_string[0] - 48 + my_int + 2]
 124     file_name += map[file_string[2] - 48 + my_int + 1]
 125     file_name += map[file_string[5] - 48 + my_int + 6]
 126     file_name += map[file_string[1] - 48 + my_int + 5]
 127     file_name += new_char[0,1]
 128     file_name += map[file_string[4] - 48 + my_int + 7]
 129     file_name += map[file_string[6] - 48 + my_int + 4]
 130     file_name += VIDEO_FILE_EXTENSION
 131
 132     return file_name
 133   end
 134
 135 end