I have a Pavilion 500-205eo, a model sold in Scandinavia, product code F9P08EA#UUW.
This is based on the MSI MS-7778/JasmineR motherboard with the IDT 92HD73E audio codec. It also has an nVidia GeForce GTX 645 card installed from the factory. It runs Windows 8.1.
My question is if it is possible to enable Dolby Digital Live over S/PDIF in Windows Games that support it. So far, I haven't been able to get it working. The S/PDIF does pass Dolby Digital and DTS when tested from the audio setup, but then it presumably only plays back prerecorded streams.
To my understanding, Microsoft has licensed Dolby Digital Live for Windows 8, so it should be available so long as the hardware and drivers allow it. But I don't know where the encoding is done (aboard the audio codec or CPU) and if it the IDT audio codec built into my Pavilion simply doesn't handle encoding of AC-3 (its data sheet doesn't mention any encoding abilities).
It might be an issue with the drivers for the IDT codec not supporting it/not being configured by HP to support AC-3 encoding. The PC was marketed as having only DTS Sound+ and 7.1 audio over its analog outputs, so it's entirely possible.
Would I need to get a third party sound card with explicit support for Dolby Digital Live to get it working?
