converting wmv(MSS2) on-the-fly/ in memory/ with buffer/ no files

I have a buffer of a video in WMV Screen (MSS2) (not the basic codec, but another codec of WMV).

I know I can use Windows media encoder but as I mentioned, I have a buffer of the movie and I don't want to use any files in the conversion proccess. I want to convert my WMV Screen buffer to a regular WM开发者_运维问答V codec or any other supported silverlight video format like h.264\MPEG-4.

Thanks.