A quick search on CPAN yielded no results for RealAudio streaming or any (relevant) results on RAM as a file format.

As far as I know, the RealAudio format is closed and proprietary. Attempts have been made to reverse engineer the protocols and formats, but they change so often it's a losing battle.

Any particular reason it has to be in RealAudio format? There's a particularly good Apache module (mod_mp3 if memory serves) that handles the streaming of MP3 audio. I find the fidelity and dynamic range of MP3 to be far superior to that of (streamed) RealAudio.

Hope that helps.