[Openvortex-dev] Some more mixer stuff

[Manuel Jander]

Hello,

I have been investigating a little more the mixer issue. I conlcuded
that the Windows driver uses the AC97 codec mixer in a very different
fashion. All AC97 pass through settings are muted, and the audio is
captured by the ADC, and routed back to the codec throught he DAC's.
This way, any analog input can be passed throught the Hardware EQ too.
Well, this semes a good idea to me, since it will solve the Quad output
routing issue once for all and ever.
I'll try to implement this when i get a time, but sure if someone else
could do this, would be great.

Regarding the A3D, it really doesnt seme too hard. I think that many
work can be recycled from the OpenAL source from Creative Labs, because
its just the same like the original A3D api. I guess you all know why...
There are A3D hardware "sources" blocks. They consist of a HRTF block
(gives positioning), Atmospheric filters, and something called "DLine"
and "ITD", which i guess has some roleplaying with reflections. The code
to program the HRTF and atmospheric filters is already translated. Whats
missing is 
-routing, 
-extract somehow the HRTF data out of the A3D.DLL file
-A3D parameter updater mechanism (we could use the hardware timer
and some kind of event queue).
-Glue into OpenAL (well, there isnt much choice. DirectX isnt very
appealing to me).
-Crosstalk canceller (less important, we can use headphones)

Best Regards

Manuel Jander