Dolby Digital 5.1 -> PC input?

[Asterra]

This seems to be one of those things I (and probably a lot of people) took for granted but am discovering to be either more difficult than I can handle on my own, or outright impossible. As the topic suggests, I'm trying to take Dolby Digital 5.1 (from a game console, over optical) and get my PC to decode it, or do whatever it needs to do so that it understands it now has six channels of surround sound streaming in.

I feel like it ought to be a piece of cake. But the method certainly eludes me. I do have optical in (two of them, in fact). But I don't know what steps are needed to get the PC to decode the stream properly, and then add the result to Windows 7's mixer.

I bet plenty of people could benefit from this info.

[Nelson37]

Either pass-thru, for playback, or capture as DD-Wav. Takes special sound card. Search on Capture AC-3.