RC7, although the PS2 does have an optical out, it does not do dolby digital in game on the fly. There are a few games that do dts in cut sequences (cut scenes) but that's it. The PS2 is incapable of doing dolby digital in game. The Xbox is the only system with this capability. GameCube can only do dolby surround II, which is a fake 5.1, ad not nearly as good as true 5.1 and your reciever has to support this technology.