Please Help Me Confirm (re: Atmos)

[FockerRN]

Quick background: Recently installed Atmos rig with Anthem 720 receiver, but keeping my 1080p projector. Hoping to find a streaming service for movie rentals that doesn't do what Vudu does - link the Atmos audio with detection of a 4k/UHD display.

I configured the AppleTV 4k, updated the firmware, enabled Atmos, and rented an Atmos film - Aquaman. Atmos logo shows up on the info screen for the ATV, but on the receiver it says "multichannel PCM". Further investigation indicates the AppleTV screen (on the Atmos configuration page) that Atmos audio is sent via LPCM. So I just spent the last hour troubleshooting, trying to isolate variables and understand why I'm not getting atmos, when I happened to stumble on to this forum.

Can you guys and gals please confirm any or all of the following for me:

1) ATV4k CANNOT output Atmos via bistream. True or False?
2) ATV4k CAN and DOES output Atmos via "Dolby MAT". True or False?
3) Atmos via Dolby MAT (HDMI) IS in fact ACTUAL Dolby Atmos? True or False?
4) What is the highest audio resolution that the ATV4k streams iTunes films at? (e.g TrueHD, DD+, etc)

Thanks kindly

 

[priitv8]

1) ATV4k CANNOT output Atmos via bistream. True or False?
2) ATV4k CAN and DOES output Atmos via "Dolby MAT". True or False?
3) Atmos via Dolby MAT (HDMI) IS in fact ACTUAL Dolby Atmos? True or False?
4) What is the highest audio resolution that the ATV4k streams iTunes films at? (e.g TrueHD, DD+, etc)

1) True. Bitstream output was blocked since late version of tvOS 11. So Infuse et al are unable to do it now as well.
2) True. https://photos.app.goo.gl/k35xfPL1JhwDQ1W88
3) True. Just the channels have been decoded from E-AC-3 into PCM. Objects and metadata are stuffed in. How, I have no idea.
4) DD+. Mad Max Fury Road shows me 770kbps.

It would be wishful thinking to hope for a lossless audio from a streaming service.
PS Dolby MAT 2.0 ought to be part of Atmos certification from Dolby. Meaning any Dolby Atmos capable receiver should be able to receive and decode also MAT. Can you check with the vendor if they have a firmware update available?

 

[FockerRN]

Thanks Priitv8...this has really been driving me nuts. I'm going to follow up with Anthem to verify in the morning, but now that I know this Dolby MAT thing exists, and I can confirm that the ATV is showing Atmos on the "info" display as I'm watching the film, I'm pretty confident that I am actually getting Atmos. It sure sounded iike it when I was testing the stream, but I haven't had this system up long enough where I can discern small differences yet - especially with Atmos.

Really glad I stumbled in here. I wish this forum had popped up on my search a bit earlier in the evening...would have saved me a lot of time lol.

 

[priitv8]

I'm going to follow up with Anthem to verify in the morning, but now that I know this Dolby MAT thing exists, and I can confirm that the ATV is showing Atmos on the "info" display as I'm watching the film, I'm pretty confident that I am actually getting Atmos.

I remember many Denon owners were also upset in the beginning, but it seems Denon has since then fixed this MAT support issue.
MAT should exist, because Dolby themselves describe it minimally in their whitepaper.
See section titled "Dolby Atmos in Dolby MAT" on page 12.

 

[JasonHB]

I have an Anthem MRX720 as well and can confirm that I always get Atmos in the display on the Anthem.

No issues at all with my ATV4K set up on it.

 

[priitv8]

Thanks Priitv8...this has really been driving me nuts.

If you are interested in intricacies of object-based immersive audio, I suggest you read the thread on avsforum starting from this post. Very interesting discussion is unfolding there! The poster FilmMixer seems to be in the business himself