Slerch has a direct answer to the secret sauce issue. He stated that the 7.1 channel signal has added information when the feed is Atmos coded. We don’t know what actually happens in the translation to the 3D soundstage because that information isn’t yet available. Proprietary? My question and motivation is to make sure that Dolby Atmos is adding data to the stream rather than “electronic manipulation” of the information present. I personally don’t understand but I trust JRiver as an interested party with nothing to gain or lose from this discussion has a better understanding but still opacity persists.
What opacity are you still looking to trying to turn transparent?
I don't work for MC but I told you exactly how it works, at least an end user level. Dolby and DTS and Auro have it in their best interest to obfuscate. How it is engineered is complex. There are Youtube channels that show the process if you look.
MC has it in their best interest to support every format they can, because they are a MEDIA CENTER application and if they don't you could go somewhere else for your fix. It also behooves them to just support it and not advertise how they are potentially skirting messy issues like patent infringement and laws (assuming they are!). The reason almost every Media Center app can support these formats without paying to license the technology is because people have reverse engineered the formats and found ways to build open-source libraries that can be used to decode or bitstream the data, unmolested, from whatever file format you have to your receiver or TV.
If you want to understand how the magic is done in the open-source libraries, best to go ask the software engineers developing and supporting it, not JR.
Jim H and the MC will never come out and tell you how they do it, why they do it the way they do, or provide any technical detail because none of them wish to be sued by a company with a market cap 10-100s of times more than JR as a company.
The enhancement layer for ATMOS includes spatial data that the receiver, if configured and has all requisite speakers in place, will "place" sound around you when done well.
It is extra data and not manipulation. This is not me making things up, it is exactly how it works and you can dig into it as I have via Youtubers who are much more eloquent than I, and who have an actual deep understanding of it that I never will.
As another member stated, you probably want speakers above you to get the best experience though there are other ways to get an OK experience out of Dolby ATMOS. Spatial computation is proprietary. Just as it is for DTS Neural:X and Auro 3D. None of these formats has been reverse engineered into a non-proprietary format, nor can they be transcoded into an open-source spatial format, but at least with DTS:X and ATMOS, we can tell you they are, absolutely and unequivocally, additional data, LAYERS, that ride the related stream. If your receiver has it and you have configured it all correctly, it plays and throws sound around you magically. If you don't, it simply plays the 5.1 or 7.1 lossless DTS or TrueHD information.
How do we know they are layers, just like Dolby Vision being a layer on top of HDR10? For one, using MakeMKV (or MakeMKV built into MC) you can see the data format. At one point in the past, MakeMKV would actually ignore the Dolby Vision enhancement layers and just give you HDR10 rips. Now you get the full HDR10 and DV enhancement layer.
When you rip a UHD or BD w/ ATMOS encoding (or DTS:X), you can choose to throw away the enhancement layer when you rip. Not ripping it does not negatively impact the audio quality of your rip, outside of only using the compressed layer instead of the TrueHD or DTS-HD MA layer.
Disney+ and a lot of its film library I think is encoded with Dolby "ATMOS." "ATMOS" and not ATMOS because the enhancement layer rides a non-lossless DD+ layer.
At least its Star Wars films and MCU stuff are absolutely "ATMOS." It is added data. Whether "ATMOS" or ATMOS.
It is a layer. If the hardware and the layer exists, it plays ATMOS (unless you set your receiver to only do Stereo or Pure or something, in which case it will still pass ATMOS, but your receiver will downmix from ATMOS to Stereo). ATMOS does not "manipulate the stream" that exists. For services like Disney+, however, you will get the Stereo OR the "ATMOS" streams in some cases depending on what you choose. On streaming services, "ATMOS" is still a layer but instead of riding a data heavy format like lossless Dolby TrueHD, it instead rides a Dolby Digital AC3 stream, affectionately known as E-AC3 (enhanced AC3). AC3 is the designation for the original Dolby Surround format. You will also find E-AC3 ("ATMOS") streams for foreign languages on the Disney+ UHD BD releases. The primary language, English, will be real Dolby ATMOS riding the TrueHD stream. Or has been thus far.
If you think that your data is being manipulated, then
set your new receiver to PURE mode or whatever the manufacturer's equivalent mode is. Begin bitstream playback of the data to your receiver from MC and see what does/does not light up on your receiver.
One thing you may need to look at is how your receiver is configured. My old Marantz, as I stated above, CAN and DOES "upmix" audio to ATMOS if I CHOOSE to let it do so by choosing the ATMOS/Dolby Surround option when I am playing movies or music back. The result can be OK at best and crap at worst. If you can set the playback mode of the receiver based on the input you could set your MC PC to Pure or Stereo and your UHD/BD/DVD player to ATMOS/Dolby Surround and have your music in stereo (or surround if it is encoded that way, as PURE plays the data as it is sent to the receiver) from your PC and your movies in surround.
What other information are you looking for?