Atmos and Sony 360 RA compatibility and transcoding

[César]

I've been doing a bit of research about Sony 360 RA, just to find out it's a compatible encoding algorithm with MPEG-H. So it's nothing "special" in the end, just another choice to mix music using an object based algorithm, based on a codec related (loosely) to the well know MP3 and MPEG.
If 360 RA is not so proprietary to Sony, I thought there should be some way to re-encode a MPEG-H stream into a Dolby Atmos container.
And voilà, I wasn't wrong. I found here that such a tool already exists, although it seems it takes Atmos files and convert them to MPEG-H:
https://www.audioblog.iis.fraunhofer.com/mas-expansionExtracted from the site:
What exactly does the MPEG-H Conversion Tool do? The MPEG-H Conversion Tool converts various profiles of BWF/ADM, the open NGA standard, into either the comprehensive MPEG-H BWF/ADM format or our MPEG-H Production format. Both target formats are PCM audio with a versatile set of metadata, including the positions of audio objects, the properties of MPEG-H presets, and volume information. The big advantage for users is that it’s now very easy to transfer BWF/ADM files created with, say, the Dolby Atmos Production Suite to MPEG-H BWF/ADM and to continue using them in an MPEG‑H‑based environment.

With AVR manufacturers starting to support Sony 360 RA by means of a firmware upgrade (in the newer Denon or Marantz models, for example, but unluckily not in my SR7011), it would be a fantastic find to get a tool that could get the 360 RA files from Tidal and transcode them to Atmos. As the link says, they are both based in PCM and only the metadata should be translated. And yes, forget for a second about the legalities involved, this is just theory for now.

What do you think? @HomerJAU , do you envision a MMH with such a feature?

 

[César]

I forgot to include this explanation, that links MPEG-H and 360RA:
MPEG-H Audio is the industry’s most advanced audio system for UHD-TV and streaming. It supports immersive sound and allows users to adjust elements in the audio to their preferences. MPEG-H has been on the air since 2017 on all TV networks in South Korea under the ATSC 3.0 standard. It has also been selected for new broadcast standards to be launched in China and Brazil and is the distribution format of the 360 Reality Audio ecosystem for immersive music streaming services.

 

[HomerJAU]

It’s been known for a while Sony 360 Reality Audio is based on the open MPEG-H 3D standard.

I think you’ve misunderstood the MPEG-H conversion tool you quoted. It can convert ADF (Audio Definition Models) created by Atmos system to MPEG-H format. ADF is not made public it is used to create the encoded mix in the studio as is not distributed (like the PCM multitrack masters).

Creating Atmos requires a Dolby Atmos Encoder and special hardware. It’s expensive. BTW: Amazon provides an online Atmos streaming encoder (pay by the content minute) that’s not too expensive (DD+ only not TrueHD).

 

[afalout]

Special hardware? I am not aware of that.

Anything you hear on streaming services today, is DD+ transport stream.

Regarding the conversion between the 360RA/Atmos, yes it can *technically* be done. How would that sound, is another matter entirely. At the moment, my ears still hurt from some examples I heard.

It may (or not) get better over time, but this is a very complex subject, not just technically but aesthetically too. I have my doubts that any material created this way will be acceptable for commercial release for many years to come. Which is why I know of at least two studios that work on mixing same material in Atmos and 360 in parallel...

 

[alek2702]

Special hardware? I am not aware of that.

Anything you hear on streaming services today, is DD+ transport stream.

Regarding the conversion between the 360RA/Atmos, yes it can *technically* be done. How would that sound, is another matter entirely. At the moment, my ears still hurt from some examples I heard.

It may (or not) get better over time, but this is a very complex subject, not just technically but aesthetically too. I have my doubts that any material created this way will be acceptable for commercial release for many years to come. Which is why I know of at least two studios that work on mixing same material in Atmos and 360 in parallel...

The Tidal 360RA mixes decode to plain old 7.1.4 speaker layout, couldn't that be accurately encoded back to channel-based Atmos?
Curious what the stuff you heard was.

 

[LennonCobain]

From my personal experience, decoding 360RA to 5.1 almost always results in fairly significant differences when compared to an Atmos 5.1 stream capture of the same material. I have no reason to doubt the accuracy of software-based 360RA conversions, so it appears that there is usually a distinct 360RA mix and a distinct Atmos mix (which seems odd that record labels would elect to incur additional costs).

 

[alek2702]

From my personal experience, decoding 360RA to 5.1 almost always results in fairly significant differences when compared to an Atmos 5.1 stream capture of the same material. I have no reason to doubt the accuracy of software-based 360RA conversions, so it appears that there is usually a distinct 360RA mix and a distinct Atmos mix (which seems odd that record labels would elect to incur additional costs).

The 360RA decoder pretty aggressively flattens the height layer when you select 5.1 output.

You can get much better results decoding to the native 7.1.4 and doing a more logical mixdown (so front heights to fronts, surrounds to surrounds, like Atmos does).