If using the new HandBrake AAC + AC3 mixdown for the appleTV, you will get an aac dpl2 mixdown if you select a DTS source soundtrack. AC3 is passthru and can *only* passthru an AC3 source.
If using the new HandBrake AAC + AC3 mixdown for the appleTV, you will get an aac dpl2 mixdown if you select a DTS source soundtrack. AC3 is passthru and can *only* passthru an AC3 source.