Pass-through plugin for audio input

I'd like to write a free DRM plugin which would accept a binary file, decrypt 
it and then pass the binary stream onto XMMS for further processing (such as 
data type detection, decoding and playing).  I have never written anything 
for XMMS, so I wwas hopeing that you might be able to point me in the right 
direction.

Example code which does something similar would be great.  I will be writing 
in C++, so examples in that language would be preferred, though not required.

Thank you for your assistance.

Garrett Kajmowicz
[email protected]