@blutfahne: somebody asked he answered..or would you prefer he just posts a page of herpy derpy Derp..You would probably understand that better,seems more on your level

Steam tag is stupid, I never use it or even look at it. So, yay for gamers who exploit something pointless?

also I haven't had any problems with uplay, so cry me a river.

PCM is basically just the audio channels being straight to your device by the game. DD and DTS are encoded signals, both limited in their bandwidth. Sort of like getting MP3's instead of FLAC. You can encode games into DD 5.1 if you have the right sound card and download the right plugin. Games don't have DD or DTS encoding built in because there's zero need for it. DD and DTS are more accessible and can be sent over an optical cable, unlike lossless signals.