Feature request : play local Atmos files

Hello @dbsquaremedia, welcome to Sonos Community!

Thank you for the kind words and feedback.

I’ve marked this thread as feature request and forwarded it to the appropriate teams for consideration.

Interesting idea… I can't really code but these days I guess I could ask Chat GPT to do it for me… But I can't really see how to add this service to the Sonos app neither how this could work…

Atmos Master files are called ADM (Audio Definiton Model), those are huge files (several Gb for 1 song) and not intended for distribution. It's a 128 channel Broadcast Wave (a 7.1.2 “bed” track + 118 mono tracks with 3D panning metadata).

From those ADM files you can basically generate two kind of lossy distribution files : TrueHD (high quality, mainly for BluRay disks) and Dolby Digital Plus JOC mp4 files (lower quality, usually 768 kbps bitrate, for online distribution services such as Apple Music / Tidal etc...)

As always with Apple, they add their secret sauce to the ADM file to make it proprietary “Spatial” (they add some elements of head tracking, compatible only with some of their headphones).

That's why the headphone (binaural) version of an Atmos Mix sound different on Apple and Tidal.

Not sure if you solved this. I am also an Atmos engineer.

This can be done by using a folder on your computer that syncs with Sonos App on desktop and Sonos App on phone. You put the mp4 file in that folder, sync to the server. The track is available via the phone app for playback on Sonos.  

Hi, thanks for your reply. 
If I’m not mistaken you can indeed have playback with this method, but it’s only a stereo fold down, not Atmos playback

Maybe this has changed, I’ll give it a new shot when I have a chance…

I can confirm the .mp4 file plays back as a full Atmos mix via this method.  

Here are some basic instructions

1. Make sure Desktop computer stays powered on and connected to same wifi as SONOS
2. Download .mp4 file (Atmos file)
3. Create a local folder on desktop for SONOS playback files
4. Drag the .mp4 download into that folder
5. Download and Open SONOS desktop app
6. Settings > Music Library > point to the folder you just created
7. In SONOS desktop app go to > Manage > Update Music Library
8. Track is now available for playback via SONOS Desktop or Iphone APP

***The file lives on the desktop computer and plays remotely via wifi broadcast on the home network to SONOS

It indeed has changed ! It works now with this method. Thanks a lot @tboston007 for letting me know and thanks @Sonos for eventually implementing this feature.

😊

It is a much better workflow for listening for me as our Sonos is more of a sound system with no TV connected. This method works great!!!!

Maybe I did not understand the problem discussed over here, but as I recognized some months ago from the Sonos music library you can play mp4 Atmos files.

Fascinating! For those that had never previously heard of “DD+ JOC” audio format (eg me!), here’s some info:

https://professionalsupport.dolby.com/s/article/What-is-Dolby-Digital-Plus-JOC-Joint-Object-Coding?language=en_US

Hey there,

I have just bought an Era 300 and the sonos app does not recognise my .mp4 atmos files from the library folder I assigned inside the app.

Is there a solution for this?

Thanks

MP4 is a container, what codec is used? Needs to be in DD+ JOC format, that is the only format known to work. Sonos don’t document any of their supported formats for spatial audio, this thread is the sole reference we have.

well it is an .mp4 export from the standalone Dolby Atmos Renderer.

it doesn’t have any codec options so I assume it is a DD+ JOC codec?