Open source 3D positional audio (HRTF)?

Question

I am in need of positional audio for my emulator RetroCopy (http://www.retrocopy.com) . I am currently using DirectSound 3D however it has many issues when I am in the 3D world of my emulator. Instead of trying to hardcode fixes for a single platform I thought it would be better to use software positioning of my buffers that I output to a simple stereo output. Thoughts?

Answer 1

How important is the Up-Down component?
I produced an audio toolkit that degraded to simple L/R panning on platforms where the HRTF was not available. For many games, where most of the action tends to take place on roughly the same plane, this is more than sufficient to provide the right positional cues to the player.

This is simple to implement: Use the angle between viewer and source as an input to a constant-power panning algorithm.