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Author Topic: Atmos  (Read 1365 times)

hvac

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Atmos
« on: June 06, 2024, 09:50:42 am »

I have looked. I still don’t see any direct information. Does ATMOS from Dolby add anything to the 7.1 HDMI output from JRiver equipped Computer? I send said output to my Atmos equipped Danon 3800 AV receiver. I see that it receives the 7.1 signal and outputs a new surround sound called ATMOS. Other companies are also competing with their proprietary surround systems.
My question, 7.1 input then something wonderful then even more channels giving a three dimensional sound. Do any of you know how the extra data in the magic box is derived? Online sources including Dolby just say it happens but not how. Audio reviews are not any better in revealing what happens.
My suspicion is that it was not meant to be public knowledge. Or maybe JRiver can help as they don’t have a dog in this fight. Or am I missing something.
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slerch666

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Re: Atmos
« Reply #1 on: June 06, 2024, 10:25:26 am »

Dolby doesn't really want you to know how their secret sauce works.

Like Dolby Vision, my understanding is ATMOS is an enhancement layer laid on top of a TrueHD package.
If you receiver can decode ATMOS, it sees the layer and switches to the object based ATMOS playback; it is layered on top of the TrueHD signal automatically.
If your receive doesn't decode ATMOS, it just plays the standard TrueHD package without enhancements.

No one, as far as I have seen, has transcoded ATMOS into some other 3D format that retains the object based elements.
Any time transcoding is needed, it is performed only on the TrueHD piece with the ATMOS layer being ignored completely. It does not matter the product; they all do this when transcoding.

If you set JRiver MC to bitstream audio, it adds nothing to the mix, does not transcode, and sends the unfiltered, unaltered bits to your receiver to work its magic.
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hvac

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Re: Atmos
« Reply #2 on: June 06, 2024, 10:44:18 am »

Good to know, another question, many streams of music and movies seem to light up the Atmos indicator light on my receiver. They can’t all have been imbued with the secret sauce, can they. Or are they really playing to my machine with newly added data at the source?
I don’t know how to be politically correct with this question, does JRiver have any reason to avoid this question? Or to avoid looking deeper for an answer? That question alone might involve proprietary information. I come to JRiver because of the balance and advanced understanding of any other issues.
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slerch666

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Re: Atmos
« Reply #3 on: June 06, 2024, 02:54:32 pm »

Good to know, another question, many streams of music and movies seem to light up the Atmos indicator light on my receiver. They can’t all have been imbued with the secret sauce, can they. Or are they really playing to my machine with newly added data at the source?
I don’t know how to be politically correct with this question, does JRiver have any reason to avoid this question? Or to avoid looking deeper for an answer? That question alone might involve proprietary information. I come to JRiver because of the balance and advanced understanding of any other issues.
Are you using MC w/ music when the ATMOS light comes on? If you've ripped from a BD an ATMOS track with the ATMOS layer intact and are doing bitstreaming, that would make sense. Or if you have found a way to "permanently borrow" a rip of an Apple Music ATMOS encoded track, that would explain it as well.

MC cannot and will not magically encode anything into ATMOS.

If you are using Apple Music ATMOS spatial music may work on your receiver if the Apple streams are ATMOS enabled. I don't have an Apple TV and don't use Apple Music so I can't do anything other than speculate.

Amazon supports ATMOS as well but not to receivers (that I am aware). Only works to their devices and I think SONOS.

On my Marantz receiver, I can enable faux ATMOS with the receiver from any source. It will "upmix" at the receiver level if I let it. I don't let it.
If something supports ATMOS my receiver will switch it from Stereo to ATMOS automatically then remembers to go back to stereo on non-ATMOS sources.


If you have a UHD or BD rip, or are watching a BD/UHD that has ATMOS, you enable bitstreaming and it sends ATMOS to your receiver.

MC won't add data to your sources and will only send ATMOS via bitstreaming if you enable bitstreaming AND the audio has ATMOS encoded into it. Otherwise you get TrueHD to PCM if you transcode (or DSD I guess if you choose to transcode to that).


I don't think JR have any reason to avoid the question.
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DocCharky

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Re: Atmos
« Reply #4 on: June 07, 2024, 02:07:49 am »

Your question seems to imply that there’s a hidden conspiracy surrounding Dolby Atmos, but that’s not the case.

A large number of high-budget TV shows and films are now mixed with Dolby Atmos. If you bitstream your media with MC to a device that’s compatible with Atmos and it responds, then your media does indeed have an Atmos track.

The perceptible difference and your ability to hear it will largely depend on the mix (some are subtle, others are not) and your setup (speakers that simulate Atmos by bouncing sound off the ceiling are almost placebo. The only authentic way to experience Atmos sound is to have speakers positioned above the main listening position).
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Charky

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hvac

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Re: Atmos
« Reply #5 on: June 07, 2024, 09:34:31 am »

Conspiracy is too strong of a word. Makes me sound like a nut. No, I have looked as I said before. I’m quite surprised that the information, see above, isn’t being discussed in the audio press. As I mentioned above, the secret sauce might help me understand if there’s new data in addition to the 7.1 feed. It seems that there is but no one knows what or how.
What is faux Atmos? Maybe that’s the reason my Amos receiver gives an Atmos signal when I get a stream of AV data, usually a movie that isn’t likely to be Atmos encoded.
Inquiring minds,  scientific curiosity,  etc.
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rec head

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Re: Atmos
« Reply #6 on: June 07, 2024, 09:52:39 am »

Faux Atmos might not be the description here. Some people use the term faux Atmos for mixes that don't use objects but rather pan sounds to a specific speaker.

The most common way to get Atmos from MC as stated above is to rip a bluray that has an Atmos soundtrack and set MC to bitstream. Your AVR can upmix with Dolby Surround upmixer to use your full channel count. So it can take stereo (or 5.1, etc) content and upmix it to as many channels you have including height channels. The fact that it is taking a 7.1 input and calling it Atmos is misleading at best. It should say Dolby Surround or something similar.

Sorry I can't explain what is happening during upmixing.

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hvac

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Re: Atmos
« Reply #7 on: June 07, 2024, 10:24:01 am »

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.
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DocCharky

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Re: Atmos
« Reply #8 on: June 07, 2024, 10:53:37 am »

I could be mistaken, but an AVR can't display "Atmos" unless it is fed an actual Atmos track.

If your AVR does indeed upmix your input signal, it should display Dolby Surround or Dsur (for a Dolby soundtrack) or DTX Neural X (for a DTS soundtrack).

This is how my Denon operates, as do Onkyo and Yamaha AVRs. I'm fairly confident that this is how all AVRs function because these are likely contractual naming conventions. I doubt Dolby would allow an AVR manufacturer to mislead customers by displaying "Atmos" on the OSD if it's merely upmixing.

In fact, if I recall correctly, some (or perhaps all) AVRs will display "Atmos" on the OSD regardless of the speaker configuration. This is because Atmos refers to the entire object-based audio system, not just the presence of a height channel.

Anyway, there’s no secret to how Atmos works. Countless videos explain how to mix in Atmos. Even the Wikipedia page is crystal clear. It's not post-processing, it's a different way to mix audio.
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Charky

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slerch666

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Re: Atmos
« Reply #9 on: June 07, 2024, 02:32:50 pm »

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?
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JimH

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Re: Atmos
« Reply #10 on: June 08, 2024, 01:06:52 am »

Thanks, Steve, for the very helpful post.  I added it to the wiki here:  https://wiki.jriver.com/index.php/Atmos
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hvac

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Re: Atmos
« Reply #11 on: June 08, 2024, 10:14:29 am »

Slerch,
  I give you credit for the first answer which discusses the DD layer in Atmos and added data at that level. Atmos has added something to enhance the 3 dimensional structure of the soundstage.
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hvac

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Re: Atmos
« Reply #12 on: June 08, 2024, 11:03:11 am »

Slerch,
   Where does the secret sauce, extra data, come from? Are there 20+ microphones in the recording studio? My guess is it’s manufactured by “electronic enhancement” like turning mono into stereo of old.
   I appreciate your comment about JRiver and its relationship with Dolby Labs. Gotta play nice in the sandbox.
   I suppose the best explanation I can give is that the data added by Dolby is proprietary. No conspiracy necessary.
   Your explanation tells me what is going on here, it’s not in the lay press. And I thank you for your candor and for your expertise.
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tzr916

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Re: Atmos
« Reply #13 on: June 08, 2024, 11:07:22 am »

When bitstreaming Atmos, JRiver isn't doing anything special. The audio just gets passed through untouched to your AVR. Same with any bluray player, streaming device, etc.

https://www.klipsch.com/blog/what-is-dolby-atmos-and-how-does-it-work

Just one of many articles found... "The general concept behind Dolby Atmos is that sounds are encoded as “objects.” Instead of sending an audio track to a specific channel, sound designers can assign an audio track to a location in the theater or room, including overhead."
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DocCharky

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Re: Atmos
« Reply #14 on: June 08, 2024, 11:35:31 am »

This is starting to feel like conversing with a brick wall.

Slerch,
   Where does the secret sauce, extra data, come from? Are there 20+ microphones in the recording studio? My guess is it’s manufactured by “electronic enhancement” like turning mono into stereo of old.
   I appreciate your comment about JRiver and its relationship with Dolby Labs. Gotta play nice in the sandbox.
   I suppose the best explanation I can give is that the data added by Dolby is proprietary. No conspiracy necessary.
   Your explanation tells me what is going on here, it’s not in the lay press. And I thank you for your candor and for your expertise.

Your "guess" is incorrect. If you had read the previous posts and the provided links, you wouldn't even have to guess anything.

Dolby does not "add" or "modify" anything. There is no "electronic enhancement". It is simply a method for mixing sound. At a basic level, each sound on the track is an object that the sound engineer positions on the sound stage. For instance, the sound engineer might take "helicopter_sfx.wav" and position it above the listener. This information is then relayed to the AVR, which plays it through the height channel.
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Charky

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hvac

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Re: Atmos
« Reply #15 on: June 08, 2024, 11:59:03 am »

Charky,
  I asked. When my suggestion was incorrect I demurred. Rather than point out the fact that I don’t know, an answer could be provided in clear English. I’m not facile with the intricacies of IT. So you can talk to me like a fifth grader if you like.
  I’ve read perhaps more than you regarding the Atmos issue that I have raised. Atmos signal to Atmos enabled decoder to playback of object based multi channel data. To say “object based” is circular reasoning. Atmos is object based and the object based signal comes from Atmos proprietary data which is what Atmos does to the 7.1 channel feed. Where does the data come from? Is it collected from the recording process? To say it is not electronically derived would led me to believe you know what/where the extra data originates. So please except my apologies if you are in someway offended. In plain English, I understand that you know where this data comes from and that is what I’m looking for.
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DocCharky

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Re: Atmos
« Reply #16 on: June 08, 2024, 12:12:28 pm »

I feel like you still don’t understand.

It’s not ‘data’. It’s just sound. That's it. It can originate from anywhere. Perhaps it’s been fully recorded on the spot with a multi-microphone setup, if we’re talking about a live concert, for example. Or maybe it’s manufactured from scratch by the sound engineer who takes various sounds and positions them as desired, if we’re discussing the latest movie blockbuster. Obviously, nobody recorded the Millennium Falcon in the sky flying above a microphone. It’s a combination of sounds that have been placed there by the sound engineer.
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Charky

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hvac

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Re: Atmos
« Reply #17 on: June 08, 2024, 12:27:12 pm »

That helps. The data is manufactured or manipulated from the original 7.1 DD signal. And we don’t know how the manipulation is accomplished? So any movie even 20 years since release can be Atmos encoded with the extra object data. What ever that is, we don’t know.

Thank you sincerely for going farther than most in an area which isn’t necessarily in your wheelhouse. I get it.
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eve

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Re: Atmos
« Reply #18 on: June 08, 2024, 03:19:51 pm »

It's important to distinguish from the distributed home video atmos mix, and the original "session", as well as what a theater gets.


The home video Atmos mix is a partial 'render' of the audio, basically the entire "atmos" mix, with actual objects, gets rendered down to a bed mix which is standard 7.1 audio. This allows it to work on non atmos systems. In addition to this "bed" there's basically a metadata stream which tells the atmos decoder how to pan and shift audio OUT of the bed mix to atmos speakers, furthermore there are actual objects encoded (though not in all atmos streams, and some will have less objects than others) which are mixed into the correct available speakers at the right time.


DD+ Atmos does not have objects IIRC, just metadata. Someone should correct me on this though, if they know better.


I'm not an atmos savant, there's better people to ask than me.




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hvac

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Re: Atmos
« Reply #19 on: June 08, 2024, 06:05:42 pm »

I’m not understanding.
  What happens at each stage of the Atmos object based creation, we don’t have that explanation from Dolby Labs.
Is new data being collected at the recording studio. 30 or more discrete objects, recorded? This wouldn’t explain how Star Wars and similar old audio tracks can get the Atmos upgrade. Or is Atmos created with processing data that already exists in the 7.1 HDMI signal. Does the new Atmos object based system use 20 or 30 or more microphones to create. Then downmix etc. I doubt it. Metadata is a good word but data about data again seems circular logic.
Bottom line is new data added or electronically generated? Tell me without an IT background how it’s done.
My simple brain thinks there’s a a line between data collection then encoding then decoding. At what point is the new Atmos signal created. As they say in 2001 Space Odyssey “something wonderful.”
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arcspin

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Re: Atmos
« Reply #20 on: June 09, 2024, 02:31:00 am »

I think the Wikipedia regarding Atmos explains it in detail.
https://en.wikipedia.org/wiki/Dolby_Atmos

The application of Atmos in home theatres differs from cinemas primarily because of restricted bandwidth and a shortfall in processing power. A spatially-coded sub-stream is added to Dolby TrueHD or Dolby Digital Plus or is present as metadata in Dolby MAT 2.0, an LPCM-like format. This sub-stream is an efficient representation of the full, original object-based mix. This is not a matrix-encoded channel, but a spatially-encoded digital signal with panning metadata. Atmos in home theaters can support 24.1.10 channels and uses the spatially-encoded object audio sub-stream to mix the audio presentation to match the installed speaker configuration

In order to reduce the bit rate, nearby objects and speakers are clustered together to form aggregate objects, which are then dynamically panned in the process that Dolby calls spatial coding. The sound of the original objects may be spread over multiple aggregate objects to maintain the power and position of the original objects.
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arcspin

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Re: Atmos
« Reply #21 on: June 09, 2024, 02:44:35 am »

My question, 7.1 input then something wonderful then even more channels giving a three dimensional sound. Do any of you know how the extra data in the magic box is derived? Online sources including Dolby just say it happens but not how.

I might understand your question better after rereading it.
Are you referring to the "Dolby Surround Upmixer (DSU)" ?

Where Dolby have a technology licensed to manufacturer to implement in their receivers and processors.
If so, only Dolby Laboratories knows that secret sauce.


"Dolby Surround Upmixer (DSU) or just Dolby Surround for short is Dolby’s latest version of surround upmixing technology to expand stereo, 5.1, 7.1 and 9.1 content to support ANY speaker configuration including any number of overhead channels.
It is a complementary technology to Dolby Atmos in a sense as it can expand channel-based content to utilise all the speakers in a Dolby Atmos installation.

DSU is an evolution from Dolby Pro Logic IIz and replaces Dolby Pro Logic, Dolby Pro Logic II, Dolby Pro Logic IIx and Dolby Pro Logic IIz on home theatre receivers and processors. While it is possible to license both the Pro Logic decoders separately along with DSU, only Yamaha did so on their CX-A5100 processor. Other companies decided not to pay for dual licensing and therefore the Pro Logic upmixers are now a relic of history."

https://simplehomecinema.com/2023/05/19/dolby-sound-formats-and-upmixers/

Upmixing in general:
"The Upmix technology uses a unique algorithm which extracts the ambience from the direct sound."
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hvac

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Re: Atmos
« Reply #22 on: June 09, 2024, 07:53:41 am »

“Spatially encoded substream” “ Dolby Surround up mixer” “official representation of the object based mix” “ metadata in Dolby MAT 2.0” “expand channel based into object based” “ DSU is an evolution from Pro Logic” on and on. Many press releases and it’s explained using the same terms in Wikipedia.
Read the above phrases and think about their meaning. String these technical terms together into several paragraphs. Now you get it. The explanation has created a black box process. Metadata is the data added to the stream which in Atmos case allows the object based stream to reach each of many speakers. (I have 7.1.2 about $2000 cost above what I had before Atmos.) The “object based stream” allows three dimensional representation of the soundstage or soundtrack. And it supports any speaker configuration. This is not a matrix encoded channel. Rather it is a space encoded digital signal.
These explanations tell me in lofty technical and clever terms how Atmos achieves their 3D goals. These phrases sound good especially when discussing Atmos to impress my friends. What do they mean? Simple words explaining what in the Atmos ecosystem is being done to the original signals. Is the Atmos process “blah blah blah” using the 7.1 recording alone as its starting point? Then the Atmos process, no matter how erudite it’s explained is a manipulation of the 7.1. Very sophisticated but starting with the 7.1. I’ve read that the recording engineer has some leeway in the process of making Atmos.
Bottom line for me is, how does a 7.1 two dimensional recording become three dimensional with metadata? That’s the crux. Everything else is fluff. Either Atmos happens at the point of collecting the data, adding microphones and adding “objects “ (don’t call them channels). Or it massages the data collected when the recording was recorded from the multiple channels feed. To my mind it must be one or the other.
This thread has been allowed to continue by JRiver and I thank them for allowing me to further my knowledge. Many of the criticisms expressed have come regarding my lack of understanding of the technical language. But none has, other than saying I’m wrong, proposed an answer to the question above. Collection of data not previously collected by original recording OR massaging (you can insert any polysyllabic word) the original feed. Created not recorded.
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arcspin

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Re: Atmos
« Reply #23 on: June 09, 2024, 09:41:16 am »

In movies all sounds are added in post-production by the Sound designer and created by the Foley artist in a Foley studio.
Dialog are however recorded as much as possible live but can be enhanced in a process called Automated Dialogue Replacement (ADR) in post.

That means that the Sound designer have total control over all sound when mixing the audio tracks in Pro Tools.
It is in Pro Tools where the bed and objects are created and placed within the room.


Question: "Bottom line for me is, how does a 7.1 two dimensional recording become three dimensional with metadata"
Answer: Everything is done in post by the sounddesigner.
Answer 2: if upmixed with DSU, the Upmix technology "DSU" uses a unique algorithm which extracts the ambience from the direct sound.


"
However, very often the aim is to record as little other sound as possible. Almost all the other sound you hear - wind in the trees, clattering of cutlery, firing of weapons, footsteps on flagstones and anything else you can think of - is very often added afterwards by specialised “foley” artists, especially on big studio productions.

The advantages of this are many.

The director has more control over what is emphasised in the soundtrack
It is easier to edit without worrying about variation in background noise from take-to-take
Sounds can be “beefed-up” for dramatic effect
Foreign language versions can more easily be prepared since the dialogue is entirely separate from the sound effects.
"


"
The amount of a movie's dialogue that is recorded in post-production can vary depending on several factors, such as the filming conditions, the quality of the on-set recordings, and the specific needs of the film. In many cases, the majority of a movie's dialogue is actually recorded during the filming process on set using boom microphones and lavaliere microphones worn by the actors.

However, it is common for filmmakers to record additional dialogue or re-record certain lines in post-production to improve the audio quality, fix technical issues, or make creative changes to the script. This process is known as Automated Dialogue Replacement (ADR) or looping.

ADR is typically used when the original on-set recordings are of poor quality due to background noise, wind, or other technical problems. It can also be used to modify or improve performances, particularly in scenes where the actors' emotions or delivery need to be adjusted.

In some cases, filmmakers may also add additional dialogue in post-production to clarify plot points, enhance the story, or address changes made during the editing process. Overall, while a significant portion of a movie's dialogue is usually recorded during filming, post-production dialogue recording can be an important tool for ensuring the overall quality of the audio in a film.
"
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hvac

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Re: Atmos
« Reply #24 on: June 09, 2024, 10:13:08 am »

“Sounds are added post production…in a Foley studio. Can be enhanced by ADR.” Now I’m understanding. “The sound designer has control over the process.”
It is looks like the Atmos creation process happens immediately post production? Does this mean it can be applied to older films recorded before Atmos was created? Also since decoding is done in the home theater or elsewhere, would it be fair to say the encoding is created in the Foley studio? Now does the sound designer have leeway? I’ve read that they do? Does that leeway compromise the end Atmos product? Would it be fair to say the Atmos encoding done in the lab is where the Atoms movie is different from the usual Dolby Digital 7.1. Not just an electronic derivative of the original. Still to this lay person it is a little evasive.
You’ve cleared the air. Bravo.
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hvac

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Re: Atmos
« Reply #25 on: June 09, 2024, 10:28:44 am »

Sorry I thought of another question. How does a flat 2D recording, microphones all in the plane, become 3D? I don’t think that data manipulation can do that can it?
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arcspin

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Re: Atmos
« Reply #26 on: June 09, 2024, 10:48:56 am »

"Sounds are added post production…in a Foley studio. Can be enhanced by ADR.” Now I’m understanding. “The sound designer has control over the process.”
It is looks like the Atmos creation process happens immediately post production?
Answer: Yes, The sound is created and mixed in a studio by the Sound designer with the Director weighing in on what he or she want to emphasize in a scene.

Does this mean it can be applied to older films recorded before Atmos was created?
Answer: Yes, the studion owns all of their foley sounds that have been made in their Foley studion. Every sound is proprietary.
That is why for example a lightsaber in a Star Wars movie from 1977 can sound the same in 2018. Disney owns the sound a lightsaber makes in the Star Wars universe.

Also since decoding is done in the home theater or elsewhere, would it be fair to say the encoding is created in the Foley studio? Now does the sound designer have leeway? I’ve read that they do? Does that leeway compromise the end Atmos product?
Answer: The Director have the final say, but rely on their competent Sound designer to transfer the Directors wish into the sound mix.
https://robsummers.co.uk/the-top-10-famous-sound-designers-of-all-time/
Answer: No, the encoding is not done in a Foley studio. In the Foley studio audio track of someone walking, wind whooshing or any other sound are created and stored as separate tracks. Then the tracks are given to the Sound designer who puts everything together in for example Pro Tools (there are other similar softwares that can be used).

Here you can see a short of how it looks in Pro Tools.
https://www.youtube.com/shorts/1OTuxJ9tMYg

A longer video on how to edit sound in post:
https://www.youtube.com/watch?v=4asDEpzUFpc

What it can look like in a Foley studio:
https://www.youtube.com/watch?v=UO3N_PRIgX0&t=63s

Would it be fair to say the Atmos encoding done in the lab is where the Atoms movie is different from the usual Dolby Digital 7.1.
Answer: No, there are no fundamental difference in making a 7.1 or a 7.1.4 mix. You just add more tracks and objects.
The studio will release several different audio releases of the same movie. There can be different mixes like stereo, 5,1, 7,1, 7.1.4 included on the same Bluray-disc.
Not just an electronic derivative of the original. Still to this lay person it is a little evasive.

You’ve cleared the air. Bravo.
Answer: I'm no expert but it is fun to try to explain for myself and others  :)
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arcspin

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Re: Atmos
« Reply #27 on: June 09, 2024, 11:02:54 am »

Sorry I thought of another question. How does a flat 2D recording, microphones all in the plane, become 3D? I don’t think that data manipulation can do that can it?

Answer: Yes, If the studio have the stems (also tracks) from the original recording and with those stems (tracks) they can, make a whole new recording and place individual instruments in a 3D environment. If they do not have the stems it is not going to be a good Atmos mix, but they can still make an Atmos mix.

What are stems:
https://www.youtube.com/watch?v=l9nU1gqc44o

Mixing stereo to Atmos
https://www.youtube.com/watch?v=GxQTa5TthIg
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hvac

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Re: Atmos
« Reply #28 on: June 09, 2024, 12:52:04 pm »

Are the spacial sounds, stems then created? From sounds post production? So these sounds can be made to come from above the listener even though they weren’t recorded above. And the spacial sound, it’s like a computer generated video only involving sound.
How do you know all this stuff? I don’t find it in the lay press. Thanks again.
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arcspin

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Re: Atmos
« Reply #29 on: June 09, 2024, 01:43:35 pm »

Yes, when they have individual tracks from every instrument and vocals they can do pretty much anything with those tracks.
They can pan, lift, reverb, increase, decrease sounds every which way they want.
They can have sounds pan from left to right, back to front and up and down pretty much without any limitations.

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slerch666

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Re: Atmos
« Reply #30 on: June 10, 2024, 09:20:12 am »

Are the spacial sounds, stems then created? From sounds post production? So these sounds can be made to come from above the listener even though they weren’t recorded above. And the spacial sound, it’s like a computer generated video only involving sound.
How do you know all this stuff? I don’t find it in the lay press. Thanks again.

You didn't ask me but I know all this stuff because it is my hobby and I have dug deep when necessary. Knowing what to search for is more important than how to search.



For older films, it all depends on what format they have available to them.

If all they have is a "flat" file in stereo, fully encoded, there are some things that can be done to fake positional data but the results will range from a rank turd up to OK. Very rarely would they be able to craft an Amazing positional audio track from a fully mixed and finalized file.

If they have a separate Music and Effects mix track/reel (this would be a Stem as well), with a separate dialog tape, they can get some OK spatial results that way too. Think of it as when they mixed Star Wars, they created a stereo track with no dialog but all M&E and squirreled that away. Then when the Japanese language needs to be added, they take the mixed M&E track and layer in the Japanese dialog. Same for any other language they record. They would use production notes to match the timing of dialog and watch lip flaps to try to get audio timing close if needed.


Think of Stems as the building blocks of an audio mix. When a film is... filmed... they have microphones setup to capture dialog (and mics on actors possibly if needed) and each of those microphones is a discrete audio file, recorded as their own separate file. Each of those files could be considered Stems. Stems could also be mixed sounds in their own audio file. Then sound effects, like punches, kicks, jet engines, etc would be individual audio files as well (Stems). Because they exist as individual files, they can be placed in time and space within a Dolby ATMOS workstation (or Auro 3D or DTS:X). The positional data is saved as part of the Dolby ATMOS enhancement layer.


If they have the stems, even if they are mixed together (think about how The Beatles would get 8+ tracks of music using multiple 4 track decks) they can place those sounds in a 3D space. THe 3D Space is a 3D rendering of a square room in a Dolby ATMOS workstation. They would place those stems, as objects, within this 3D rendering, which ATMOS on your receiver will use to calculate "where" to play a sound or music que within your ATMOS enabled room. The WHEN of playing the que is part of the standard 7.1/5.1 mix which is why there is no data added in the enhancement layer, just positional data for your ATMOS system to apply an algorithm to and play the WHERE.


For music, it is the same. Each instrument in a modern studio is recorded on an individual track (which is how it was done on tape as well for the most part, except where things like 4 tracks limited a mix and instead you got mixed tracks on a reel that fed into the main 4 channel mixer). Those tracks are stems that make up the final Stereo or ATMOS mix.

In this case, the positional audio is created in the same Dolby ATMOS workstation environment and placed all around the room and zipped over and above and under as needed. This data can be read out as standard Stereo but buying a stereo only mix is likely a better option if you don't want the ATMOS version of a track.

In terms of the how, you can use Youtube to further educate yourself. You say there is no information available but there are lots of videos that go over Dolby Audio and how it is created. I don't know that you would get the answer to any very, very specific questions you have but if you ask a Youtube channel creator directly you may just get exactly what you are looking for.

In fact, https://www.youtube.com/watch?v=upG87FrDtMI, the Dolby ATMOS Music Creation 101 series is a good place to start. Not the most technically informative but is a decent enough overview and will allow you to figure out what you don't know, which should then allow you to feed that back into Youtube to get videos that give you what you want.


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slerch666

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Re: Atmos
« Reply #31 on: June 10, 2024, 09:36:12 am »

Sorry I thought of another question. How does a flat 2D recording, microphones all in the plane, become 3D? I don’t think that data manipulation can do that can it?
If the recording is its own file, the sound engineer can place it in a 3D representation of a room, anywhere they want it.

When it is mixed for authoring that data is encoded and your receiver reads that layer out during playback.

When you think about objects, those would ideally be stems (or individual audio files). The engineer would "place" the object in the 3D rendered room in the Dolby ATMOS workstation, and would then tell it where and when to place those sounds. The trajectory of a sound, think of a bullet shot from the left front that travels to the right rear, is calculated and during playback, based on the ATMOS layer (meta data) it calculates, based on what speakers you have setup in your personal system, where and when to play the sound.

If you have a 7.1.4 Dolby configured system, your receiver would calculate and determine when and from which speakers to play a sound to give you the feeling of spatial audio. When your receiver can't do ATMOS is reads the standard 7.1 mix and plays it that way, with no spatial direction included just as it would in your old 5.1 home theater etc.

If you want to know more, seriously check Youtube. So many experts and enthusiasts have an over abundance of information to share.
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slerch666

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Re: Atmos
« Reply #32 on: June 10, 2024, 09:38:47 am »

And HVAC, you don't really tell us what your setup looks like. If you haven't enabled ATMOS speakers in your receiver, the spatial data will "play" the objects but would likely end up sounding like the non-spatial enabled 7.1/5.1 mixes.

If you need/want to know how to setup your room, check out Dolby's setup guides:

https://www.dolby.com/about/support/guide/speaker-setup-guides/
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JimH

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Re: Atmos
« Reply #33 on: June 10, 2024, 11:11:33 am »

If you want to know more, seriously check Youtube. So many experts and enthusiasts have an over abundance of information to share.
Ha ha!
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