Does the HD621 "fold" the extra surrounds from a 7.1 soundtrack into the 5.1 avalable surrounds that an 861 accepts, or, do you set the player to fold those, sending the HD621 a 5.1 signal with the extra two channels already matrixed?

DirecTV HR21, Ram modded Oppo 93, JRiver MC17 on Win7 wi/SSD, Empirical Audio Ultraclock Offramp, 861v6, Bryston 28B SST2 amps, Salk 12" Soundscapes with Dueland caps, RAM modded Audyssey Balanced Pro, Lumagen Radiance, MarantzS4