I have a Radeon HD 5800 card and I'm using the HDMI port, it outputs DTS and Dolby Digital. If I watch a movie with DTS it will show up on my receiver.
If I play a game (such as Battlefield 3) it always shows up as "PCM Multi" .. I've been trying to get DD/DTS enabled while gaming but I can't figure it out. Is there a setting I need to change or something? The only setting I've found was changing the speaker configuration in the control panel from headphones to 5.1.. that changed it from 2.0 to 5.1 but it didn't enable DTS/DD