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     page_data = self.get_page_data(@url)
  58
  59     # As far as I know, the MP4s don't work yet.
  60     # So just default to the FLV.
  61     top_secret_hash = parse_hash_flv(page_data)
  62
  63     return 'http://dl.redtube.com/' +
  64            self.get_root_server_dir() +
  65            "/#{video_dir}/#{file_name}" +
  66            top_secret_hash
  67   end
  68
  69
  70   def get_video_filename()
  71     # Mildly redundant.
  72     video_id = parse_video_id()
  73     padded_id = video_id.to_s.pad_left('0', 7)
  74
  75     return self.get_file_name(padded_id)
  76   end
  77
  78
  79   protected;
  80
  81   VIDEO_FILE_EXTENSION = '.flv'
  82
  83   def parse_video_id()
  84     return /\d+/.match(@url)[0]
  85   end
  86
  87
  88
  89   def parse_hash_flv(page_data)
  90     # Hashes are generated for both flv/mp4 and are delivered
  91     # along with the video page. We need to stick them back on
  92     # the end of the final video URL, or else it doesn't work.
  93     hash_flv_regex = /&hash_flv=(\/.*?)&/
  94
  95     matches = hash_flv_regex.match(page_data)
  96
  97     if matches.nil?
  98       raise StandardError.new("Couldn't parse the hash_flv variable.")
  99     end
 100
 101     return matches[1]
 102   end
 103
 104
 105   def get_root_server_dir()
 106     # They hard code this shit into the SWF file.
 107     return '467f9bca32b1989277b48582944f325afa3374'
 108   end
 109
 110   # Not sure what they're thinking with this one.
 111   def get_video_dir(video_id)
 112     return (video_id.to_f / 1000.0).floor.to_s.pad_left('0', 7)
 113   end
 114
 115
 116   # The first part of the algorithmic magic. Multiply each
 117   # digit of the padded video id by the index of the
 118   # following digit, and sum them up.
 119   def int_magic(padded_video_id)
 120     ret = 0
 121
 122     0.upto(6) do |a|
 123       ret += padded_video_id[a,1].to_i * (a+1)
 124     end
 125
 126     return ret
 127   end
 128
 129
 130   # Part 2 of the magic. Sum the digits of the result
 131   # of the first magic.
 132   def more_magic(file_string)
 133     magic = self.int_magic(file_string).to_s
 134
 135     ret = 0
 136
 137     0.upto(magic.length - 1) do |a|
 138       ret += magic[a,1].to_i
 139     end
 140
 141     return ret
 142   end
 143
 144
 145   # Complete fricking mystery
 146   def get_file_name(file_string)
 147     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']
 148
 149     # The stupid variable names I copied from the
 150     # source script. Considering myself disclaimed.
 151     my_int = self.more_magic(file_string)
 152     new_char = '0' + my_int.to_s
 153
 154     if my_int >= 10 then
 155       new_char = my_int.to_s
 156     end
 157
 158     file_name =  map[file_string[3] - 48 + my_int + 3]
 159     file_name += new_char[1,1]
 160     file_name += map[file_string[0] - 48 + my_int + 2]
 161     file_name += map[file_string[2] - 48 + my_int + 1]
 162     file_name += map[file_string[5] - 48 + my_int + 6]
 163     file_name += map[file_string[1] - 48 + my_int + 5]
 164     file_name += new_char[0,1]
 165     file_name += map[file_string[4] - 48 + my_int + 7]
 166     file_name += map[file_string[6] - 48 + my_int + 4]
 167     file_name += VIDEO_FILE_EXTENSION
 168
 169     return file_name
 170   end
 171
 172
 173 end