The answer to your question is yes.
I'm not sure what the codec info is saying. It looks like 5.1
Dolby Atmos® FAQ
- Thread starter HomerJAU
- Start date
Help Support QuadraphonicQuad:
I'm not sure what the codec info is saying. It looks like 5.1
m4a is simply a container.
The codec here is Dolby Digital +, which can carry Atmos metadata.
It shows up as a 5.1 file because lossy Atmos uses 5.1 beds instead of 7.1 beds, from what I understood.
Last edited:
Perhaps someone with enough tech know-how can answer this question that I posted on the Revolver thread:
What I fail to understand is why 4K video will stream just fine, yet something like lossless Dolby Atmos is considered out of reach. I though that high resolution 4K video signals use much more bandwidth than any kind of audio signal? Ripping a blu-ray with video consumes much more disc space than a straight blu-ray audio; and 4K is even larger. So it makes no sense to me.
Why can't Dolby Atmos be streamed in something like 44.1/24?
Even CD quality 44.1/16 would be acceptable for Atmos.
JediJoker
Audio Engineer/Enthusiast
Streaming video is pretty heavily compressed. All consumer digital video formats use lossy compression—even UHD Blu-ray—but to accommodate streaming, the compression is turned up to 11. The bandwidth used for a 4K stream is a mere fraction of the available bandwidth on UHD Blu-ray. Consider that all versions of HDMI, including v1.0, have been multi-gigabit (up to 48Gbps with v2.1). Meanwhile, even single-gigabit Internet connections remain out-of-reach for the majority of consumers. With that in mind, Netflix's maximum streaming bandwidth is 15.25mbps combined for both video and audio. It's no wonder they serve lossy audio, as they must reserve as much bandwidth as possible for video.
Pure audio streaming, however, is a different matter. Assuming a 2:1 lossless compression ratio, each channel of 16-bit/44.1kHz audio would require 352.8kbps of bandwidth. A 7.1-channel bed would therefore require 2.82mbps of bandwidth. I'm not sure how much bandwidth Atmos metadata requires, but let's make a conservative estimate of 1mbps for a total bandwidth of 3.82mbps. It does stand to reason that this should be possible to serve and stream, especially considering that streaming providers are already serving 24-bit/96kHz lossless stereo, which requires 2.3mbps at a 2:1 compression ratio.
The first of a series of "Inside the Mix" webinars on immersive audio from the Recording Academy's Producers & Engineers Wing was posted on the P&E Wing's website last month. This one is a "Prelude: Immersive Audio 101," with Brian Gibbs, Darcy Proper, Leslie Ann Jones, Jimmy Douglass, and Michael Piacentini. "All of our panelists have worked prolifically in immersive formats from 5.1 surround sound to Dolby Atmos, Sony 360 Reality Audio and Auro-3D." "The series — which will be available on YouTube in the near future — will cover topics including deliverables and quality control, room configurations and tuning, metadata, and creative solutions."
https://www.recordingacademy.com/ne...producer-and-engineers-wing-recording-academy
https://www.recordingacademy.com/ne...producer-and-engineers-wing-recording-academy
Last edited:
Not quite the right thread for this, but new, one-off threads sometimes get overlooked, so...
The Dolby Music Team & Extended NAMM Q&A Session
Could be instructive to hear the "Team's" answers--especially if anyone poses critical questions about the buggier corners of the "ecosystem." Register here:
https://professional.dolby.com/dolby-atmos-music/Events/?lid=ve4lq4w3ci7h
The Dolby Music Team & Extended NAMM Q&A Session
Join the Dolby Music Team for a live session covering the FAQs from NAMM 2023, and answering your questions on studios, tools, resources, and the Dolby Atmos ecosystem. Wednesday, May 10, 12 noon EDT.
Could be instructive to hear the "Team's" answers--especially if anyone poses critical questions about the buggier corners of the "ecosystem." Register here:https://professional.dolby.com/dolby-atmos-music/Events/?lid=ve4lq4w3ci7h
Just skimming this after the fact: at ~37:00 and ~47:00, Christine Thomas, Dolby's "Head of Music Partnerships," says in no uncertain terms that "automated processes" and "upmixing from stereo" are not allowed--although she also says that it's effectively up to the content owners (and, secondarily, to Apple) to do QC and police those policies.
(By the way: in between those questions, another member of the team says they're currently rolling out the capability to mix and master Dolby Atmos in 96kHz--though purely for "archival" purposes for now.)
Methuselah’s Grandpa
Well-known Member
I've browsed a few forums for Dolby Atmos mixing & I've read quite a bit of the posts & comments there. What surprised me is that it seems like many of the people who are now mixing, or in the process of starting to mix Atmos, ...don't seem to me like they have been fans of surround sound, are not familiar with the back catalog, & possibly have never even listened to surround sound music before. Most newcomers seem like they've only ever mixed for stereo & want to make the next "logical step-up" to Atmos. More than a few people wanting to mix Atmos only using headphones to monitor it. I guess maybe it shouldn't surprise me given how the word "Atmos" has become a buzzword & is much more popular itself than surround sound systems are.
I have never liked the how the word "Atmos" ended up being this all-encompassing word that ends up meaning different things to different people. People who have never heard music in surround sound but listen to Atmos on binaural headphones, or some who listen to Atmos in traditional stereo, etc. I wish there was clearly different types of Atmos or labels to differentiate the playback uses, ...I get that is kind of the point of the format but I don't like it & never have since I first read about it years ago.
I feel like it would've been better if they wouldn't have had a one-word-means-everything approach.
/my 2 cents
I have never liked the how the word "Atmos" ended up being this all-encompassing word that ends up meaning different things to different people. People who have never heard music in surround sound but listen to Atmos on binaural headphones, or some who listen to Atmos in traditional stereo, etc. I wish there was clearly different types of Atmos or labels to differentiate the playback uses, ...I get that is kind of the point of the format but I don't like it & never have since I first read about it years ago.
I feel like it would've been better if they wouldn't have had a one-word-means-everything approach.
/my 2 cents
Last edited:
I can not find my answer on what is in my mind. When I read this forum every time I see members talking about quad audio releases in the past, and if the masters tape still exist, because that’s is a requirement? To get in these days a Dolby Atmos mix of that release. Why is that so important?
I’m not exactly sure what you are asking but:
Dolby Atmos offers 3D spatial surround with more speakers. Many surround music enthusiasts like a more discrete mix with isolated instruments and vocals in various locations, compared to having the same sounds from all speakers. To do this an audio mixing engineer needs master multitrack tapes containing the individual microphone and instrument recordings.
In many studios and live performances there are multiple microphones for: each vocal performer, drum kits can have several microphones, various acoustic instruments and some electric instruments may be directly recorded via cables. At the end of the recording the engineer could have as many as 40 tracks of recorded isolated instruments/vocals etc. These tracks are then mixed down to a final delivery mix, usually stereo, but hopefully for us here in QQ, 5.1 or Atmos (home Atmos systems can have 16 speakers, but the mix can have more objects which can be defined anywhere in 3D space)
An Atmos mix can’t be effective from a stereo master (an upmix). It needs the original master multitrack recordings. Hence the question: Where are the Master (multitrack) tapes ?
Dolby Atmos offers 3D spatial surround with more speakers. Many surround music enthusiasts like a more discrete mix with isolated instruments and vocals in various locations, compared to having the same sounds from all speakers. To do this an audio mixing engineer needs master multitrack tapes containing the individual microphone and instrument recordings.
In many studios and live performances there are multiple microphones for: each vocal performer, drum kits can have several microphones, various acoustic instruments and some electric instruments may be directly recorded via cables. At the end of the recording the engineer could have as many as 40 tracks of recorded isolated instruments/vocals etc. These tracks are then mixed down to a final delivery mix, usually stereo, but hopefully for us here in QQ, 5.1 or Atmos (home Atmos systems can have 16 speakers, but the mix can have more objects which can be defined anywhere in 3D space)
An Atmos mix can’t be effective from a stereo master (an upmix). It needs the original master multitrack recordings. Hence the question: Where are the Master (multitrack) tapes ?
I think you may be asking about two different things. When people ask about quad mixes, they are wondering if the master tapes - the original mixdown to 4 channel mix - still exist. Almost every QUAD mix was made 45-55 years ago and, not surprisingly, some have disappeared because they haven’t been used (or even thought about) in 4+ decades.
Atmos is a totally different - and more contemporary - thing. Ideally an atmos mix should utilize the original MULTI-TRACK tapes - not the stereo or quad master. Most popular recordings since the late 60s were recorded using 8 or more tracks (up to an infinite number of tracks now with digital recording technology) - and then those tracks were mixed down from that multi-track tape to 2 tracks to create a stereo master tape (or 4 tracks for a quad master tape in the 70s).
Atmos is a much newer technology which allows instruments to placed in many speakers throughout the soundfield. While an atmos mix can be created from the original mono, stereo or quad mixdown master tapes, it isn’t optimal. Ideally you want to have access to the original MULTI-TRACK master tapes to create an atmos mix. Simply put, the multi-track tapes provide more tools to work with - each instrument is on an individual track - so the mixer can place each instrument wherever they want in an atmos mix. Creating an atmos mix from a mono, stereo or quad master tape can be done but it requires some artificial extraction of individual instruments - and the results are generally not as crisp or convincing as using the multi-track tapes.
With all due respect, "Atmos" is explicitly defined at various technical levels, and there really isn't much gray area in that regard. For the folks who haven't the care or don't feel a need to understand Atmos technically, I agree it's just a word with a myriad of connotations.
But for a majority of QQ Forum members, and like minded audio hobbyists, Atmos should bring to mind a very similar technical and musical understanding. It is a very unique, and quite clever delivery system with a great deal of potential.
Atmos is only delivered one way (okay, streaming it has a 5.1 bed, blue-ray a 7.1 bed). I think I understand what the intent is here, but not sure why or how others listen to, or perceive Atmos is important or why it would draw our ire? So long as the audio market continues to eat it up, we can take full advantage of the format in whatever way we are able to, or in the manner we enjoy. But I don't think there are explicit ways to label Atmos for playback. That is entirely up to the system construct / choice of the user.
Apologies if I missed your point. I do have a hard time understanding a general criticism of Atmos when it is currently driving a surge of multi-channel listening opportunities...it's an extraordinary time for surround sound. I enjoy a 4.1 system, look forward to possibly trying 6.1 and Atmos in the future. But the volume (no pun intended) of discrete surround thanks to Atmos, is being enjoyed now.
Last edited:
I couldn't agree with you more!
Yes Atmos tends to be understood by different folks in different ways, also it is very scalable but can't possibly be all things to all people as it is sometimes insinuated. We do know that a $200 Atmos soundbar or a couple of bouncy-house speakers (as referred to on Audiopholics) isn't going to deliver
a life changing immersive experience. OTOH if the listeners are enjoying them and helping to add to the popularity of the codec and surround sound in general, it would be wise for us to avoid whenever possible demeaning the process. The explosion in multich releases over the last couple years has been
staggering and whether they are Quadio's 4 chs, 5.1 DVD's or downloads, new Auro recordings, etc; a big part of the reason for the renewed interest and willingness of labels to spend the money on releases can be pointed directly at the new interest in surround that was created by Atmos.
As the old saying goes, never look a gift horse in the mouth.
Nitpicking about this part of the FAQ:
As I understand it, DSU (the Dolby Surround Upmixer) is part of the Dolby Atmos bundle.
This upmixer will act on native stereo, and according to Dolby literature, 5.1, and 7.1 content too. But in my experience NOT on quad mixes, i.e. it does not upmix a 4.0 mix to 5.1. Nor is quad mentioned by Dolby. ( I have 3.0 files too,, and they are not upmixed to 5.1 by DSU).
I only have a 5.1* setup so I can't say how well it really works with upmixing anything to >5.1
*5.2 actually i.e. 2 subwoofers, but the point stands
As I understand it, DSU (the Dolby Surround Upmixer) is part of the Dolby Atmos bundle.
This upmixer will act on native stereo, and according to Dolby literature, 5.1, and 7.1 content too. But in my experience NOT on quad mixes, i.e. it does not upmix a 4.0 mix to 5.1. Nor is quad mentioned by Dolby. ( I have 3.0 files too,, and they are not upmixed to 5.1 by DSU).
I only have a 5.1* setup so I can't say how well it really works with upmixing anything to >5.1
*5.2 actually i.e. 2 subwoofers, but the point stands
What about Atmos Upmixing stereo and quad music?
New AVRs with Atmos decoders also provide an onboard Atmos upmixer. This is more advanced than previous Dolby upmixer generations. The Atmos operates on stereo, quad, 5.1 and latest 7.1 Dolby TrueHD mix.
as a "Atmos Upmix" ? LOL. Yes it does try to get a 2ch mix playing to all the base and overhead channels but there's something that personally I've never found very successful subjectively. I could swear my old Marantz Pre/Pro offered the option to upmix a 2ch source to either a Dolby mix using all the base and overhead speakers, or one that only upmixed to the base channels, AFAIR ??? I always choose only the base channels for the upmix but that was my subjective preference. Same thing with DTS, I could swear I use to have the options for either DTS Neural or DTS Neural +X, No more ???
I do still have the choice between Auro 3d and Auro 2d Surround.
So much music, so many options, so little time. LOL
New AVRs with Atmos decoders also provide an onboard Atmos upmixer. This is more advanced than previous Dolby upmixer generations. The Atmos operates on stereo, quad, 5.1 and latest 7.1 Dolby TrueHD mix.
You are correct sully but I'm not sure I ever heard Dolby or anyone else actually referred to it
as a "Atmos Upmix" ? LOL. Yes it does try to get a 2ch mix playing to all the base and overhead channels but there's something that personally I've never found very successful subjectively. I could swear my old Marantz Pre/Pro offered the option to upmix a 2ch source to either a Dolby mix using all the base and overhead speakers, or one that only upmixed to the base channels, AFAIR ??? I always choose only the base channels for the upmix but that was my subjective preference. Same thing with DTS, I could swear I use to have the options for either DTS Neural or DTS Neural +X, No more ???
I do still have the choice between Auro 3d and Auro 2d Surround.
So much music, so many options, so little time. LOL
Ok needed are the master tapes. But why are referring many users from this forum to the quad releases forty years ago? Only because they are member a long time of this forum?
And I must confess I had never heard before about Quad, only now in this last years because of Dolby Atmos. Listening to surround I do for about 15 years.
Maybe not so much because we are members of this forum, but because a lot of us started with multichannel music with Quad in the 1970's.
We have fond memories of a lot of the old Quad releases and would like to see them brought back to life. For example, many were released in a matrixed format and not in "true" discrete surround. Having the master tapes would mean someone could mix a discrete track/tracks.
Yes some of us are older than dirt. lol.
My senior project in college was to invent dirt.
My question was about the claim that a quad source is upmixed by 'Atmos Upmixing'. As far as I know, 'Atmos Upmixing" is just DSU for an Atmos speaker configuration, and as in my experience DSU does NOT upmix 3.0 or 4.0 to more channels, I was wondering if my knowledge is incorrect.
(Also, my 4.0 mixes all now have a silent C channel, so, it would be hard to tell if they are actually upmixed. If anyone else has used DSU to upmix 4.0 to 5.x or 7.x, I'd like to know)
Nice to hear this explanation many thanks.
Similar threads
