Real Alternative installs dlls that a regular installation of Real Player would install, in fact if you look in your Program Files, you'll find folders as if you would have installed Real Player. How about using this codec for the videolan? This is called real Alternative(I think 1.11 is the most recent one).
The RealMedia Browser plugin supports Internet Explorer, Opera, Netscape and Mozilla. This is a limitation of the current Media Player Classic. smil files sometimes only play the first part of a clip. smil), RealText (.rt), ReadPix (.rp), RealMedia embedded in webpages.smi and.
The included Media Player Classic supports it and works very well. You do need a player that is capable of playing RealMedia. This way you can play RealMedia files without having to install RealPlayer/RealOne Player. 'Real Alternative will allow you to play RealMedia files.