I'm interested in this player.
I compiled hvl2stream in visual studio. I had to hack together a unistd.h but it seems to convert hvl and ahx to streambits successfully.
A usage demo of the player would be nice since I didn't manage to get anything to play.
I set the parameter field as indicated in the source code : pointer to stream, pointer to AHX_FilterPrecalc.bin, pointer to AHX_panning.bin, master volume set to 255. I set REGPAGE in D_FLAGS before starting the DSP.