o.twimg.com source redirection

* mainly twitpic, but it's possible there are others
* uses base64 and uri ruby modules

app/models/post.rb

@@ -383,6 +383,16 @@ class Post < ActiveRecord::Base
         
       when %r{\Ahttps?://pic0[1-4]\.nijie\.info/nijie_picture/(?:diff/main/)?\d+_(\d+)_(?:\d+{10}|\d+_\d+{14})}i
         "http://nijie.info/view.php?id=#{$1}"
+        
+      when %r{\Ahttps?://(?:o|image-proxy-origin)\.twimg\.com/\d/proxy\.jpg\?t=(\w+)&}i
+	      str = Base64.decode64($1)
+	      url = URI.extract(str, ['http', 'https'])
+	      if (url[0] =~ /^https?:\/\/twitpic.com\/show\/large\/[a-z0-9]+/i)
+		      url[0].gsub!(/show\/large\//, "")
+		      index = url[0].rindex('.')
+		      url[0] = url[0][0..index-1]
+	      end
+	      "#{url[0]}"
 
       else
         source