Hello all. I have a HD7700 card in my home theater PC that has been there for a couple years with no issues. It feeds a 23" monitor via DVI and a BenQ W1070 projector via HDMI. I previously was using Tosliink Optical digital output to a home theater receiver, but had issues with certrain audio formats not working correctly etc, so I recently upgraded to dedicated amplification and a new signal processor. The signal processor is a MiniDSP NanoAVR HDA, which runs exclusively via HDMI input.
The problem is that I cannot get the HDMI output from my HD7700 to allow any audio format other than stereo. I've tried uninstalling the Realtek HD Audio drivers, etc, but I can't find a way to get it to work properly so far. As a stopgap, I have run the motherboard's HDMI output to feed the processor. Depending how I do so, I still get issues. If I run it solely to feed the sound, it creates a "ghost" screen, that the mouse can disappear into. Alternatively I can run it to the processor and then through to the projector from the processor's output to avoid that issue. In either of those cases though, I am running into graphics processing issues. TV signal(via SiliconDust HD homerun Prime and FIOS) is herky jerky and sometimes pixelates badly, where there were previously no issues. I've also noticed that the PC seems to be working a lot harder than before, presumably because it is now forced to handle graphics processing that was previously handled completely by the graphics card.
Basically all I need is codec support to translate the any audio format into a PCM stream the processor can read. The processor can accomplish everything else needed. Anyone have any ideas what the issue is or how to correct it?