The HiFiBerry Digi driver is still in development. Stereo output works great even at highest sampling frequencies and bitrates (192kHz/24bit). Today we tested what happens, when we output a DTS or AC-3 bitstream through the HiFiBerry Digi. Would an external decoder recognize the signal? See yourself:

It worked :-) That means there is a good chance, that DTS and AC-3 output will be supported. However, we don’t know yet if standard software like XBMC will be able to use the HiFiBerry Digi.