Realtek HD Audio Dolby Digital Optical Input From Xbox 360 Options

[DrShevek]

Hi, hopefully this is the right place to ask this question!

I'm trying to connect up my Xbox 360 to my PC and pass through the Dolby Digital Audio to my 5.1 speaker setup (my LCD has dual input, DVI for the PC, D-SUB for the Xbox).

The motherboard (Abit AB9 QuadGT) has a Realtek ALC888 chipset and I have a 5.1 speaker system connected via 3 x 3.5mm jacks (FR/FL, RR/RL, C/LFE).

I get full 5.1 output from the PC.

I have connected the optical audio cable from the Xbox to the Optical In on the motherboard's backplate.

With the Xbox in `Digital Stereo` mode I get 2 channel audio from the Xbox, through the PC, to the speakers.

With the Xbox in `Dolby Digital 5.1` mode I get no sound at all.

I previously had the Xbox optical audio connected to my Hi-Fi amp in the living room so I know that the DD5.1 output is working fine.

I have the latest Realtek drivers installed in Win 7 32-bit.

1. Is it possible to use the full 5.1 DD from the Xbox via the PC?
2. If so, am I missing some option(s) in the Realtek setup?
3. Do I need some other piece of software to do this? (AC3Filter or ffdshow perhaps)

Any config help with Realtek/AC3Filter/ffdshow would be great too!

Many thanks

Shevek