Originally Posted by Dan Hitchman
According to Roger Dressler, Dolby has already demoed Atmos on a non-standardized Blu-ray. For reasons of capacity, I would assume they were short clips, not an entire movie. I would also assume they were using TrueHD (aka Meridian Lossless Packing) to losslessly compress the main channel bed and then added the metadata controlled sound objects as extension files.
DTS probably would do something similar with a home-based Multi-Dimensional Audio (MDA) format (in fact, they also did an MDA demo using a Blu-ray disc). Both DTS and Dolby use "core + extension" type audio codecs. MDA was originally an SRS Labs invention tweaked by DTS after they acquired SRS.
However, adding a 2 hour or so video file in UHD to these object based audio codecs would require a disc well beyond the capacity of a 50 GB dual-layer Blu-ray today. Sony and Panasonic have come up with a 300 GB+ Blu-ray, so it'll be interesting to see if that's the platform they'd use.
A 7.1 channel-based track like on current Blu-ray's cannot create the pinpoint accuracy of an object rendered version using multiple speaker locations, nor does it have overhead channels. Atmos is 9.1 channels + objects (that's 7.1 plus dual overheads for just the channel bed).
Most of the electronics convention-held and private demos have relied on at most 20 or so speakers + subs. Today's upper tier consumer audio gear can output 11.2, so this is not beyond the realm of possibility in upscale home theaters, especially if they take a modular approach.
For the home, I would speculate the very basic object based layout for either Atmos or MDA would more than likely be 9.2. A 7.1 layout with two overhead speakers and an extra sub output (controlled by bass management). An object renderer can place sounds in a "phantom" location between two adjacent speakers if you don't happen to have a physical speaker in a location the original mix metadata told the renderer to place a particular sound object. Today's Atmos processor can do up to 64 speakers. If the theater doesn't have the entire 64, it does exactly that.
Today's channel based formats cannot do this level of precision.
DTS MDA can either be in a 100% metadata object bitstream or it can work like Dolby Atmos as a hybrid format with traditional channel beds + objects. Mr. Dressler was speculating that DTS would probably use the latter approach because things like sound effects ambiance, the music score, and primary dialog tracks would not need to be controlled with metadata and could be more easily anchored in channel beds.