The audio stuff is from the original mpg123 package. (with minor changes)

As long as there is no real audio support you must use
a native interface and compile the library yourself. 
I tested the audio part with Solaris and Linux. The precompiled
libraries can be found in the libnative.* directories 
in the root dir of this package.

If you need support for another platform: compile your own lib

The Makefile isn't very well designed but it may help as some
sort of 'documentation' for your platform.