Apple Mac OS crucial fault; Macs do not pass ATMOS through HDMI- any workaround to it?

[SeeMoreDigital]

I stand corrected. I'm in the pc world, know nothing much about Apple products.

Lol... Even the Apple TV 4K devices can't pass bit-streamed audio to an AVR, it's transcoded to Dolby MAT. But why make things easy for your customers to understand. That's the Apple way - USB-C "on an iPhone" anybody

 

[mandrix]

There are several options for different speaker setups depending on how much work you want to put into it, on a pc, and with the DRP.
Even a 7.1 soundcard can do 5.1.2. Two mch capable AVR's can be connected via ASIO4ALL for same or higher configurations w/wo HDMI, though HDMI certainly makes it easier.

 

[sjcorne]

Even the Apple TV 4K devices can't pass bit-streamed audio to an AVR, it's transcoded to Dolby MAT.

Sure it can, Dolby MAT is an encoded format. If the Apple TV converted everything to PCM internally like the Mac computers do, you'd only get 5.1.

 

[SeeMoreDigital]

Sure it can, Dolby MAT is an encoded format. If the Apple TV converted everything to PCM internally like the Mac computers do, you'd only get 5.1.

Dolby MAT transcodes everything to LPCM, along with Atmos meta-data... It's really quite clever!

Sme info: What is Dolby MAT? Everything You Need to Know!

 

[jimfisheye]

Yeah, there's a clue!

It looks like:
TrueHD+Atmos -> Apple MAT (which includes the still Dolby encoded TrueHD+Atmos) -> Approved Apple device supporting Apple MAT -> Atmos supporting HDMI AVR

If you don't have the Apple MAT supporting device to decode the extra layer of MAT encoding wrapping the still Atmos encoded signal, the Atmos channels get muted. They want to sell you an Apple TV or similar device.

 

[sjcorne]

To my knowledge, the only thing an Apple TV can do that the Mac computers can't is send encoded audio from the Apple Music streaming service to an AVR over HDMI. It will also play MP4s with lossy DD+/Atmos over the VLC app, but if I load an MKV or M4A with TrueHD/Atmos audio I get no sound.

 

[LB-V]

Apple MAT (

It's Dolby MAT, not an Apple MAT.

the Atmos channels get muted.

Technically speaking, Atmos beyond the bed (5.1 streaming and 7.1 blue ray) does not have any "channels" to be "muted". Provided your AVR or Pre/Pro is at least 5.1 capable, you lose nothing. The Atmos meta data information is just that, information or bits to be read by an Atmos rendering device, i.e. an Atmos AVR, to place exsting bed sounds into Atmos speakers. If there's no rendering, nothing is moved and the bed music is heard as intended.

The Atmos Soundstage is essentially created in real time by your Atmos AVR as it is played, based on the information for the placement of "objects" programmed by the mixing engineer and the actual speaker configuration set in the AVR. Absent of the Atmos renderer, you always get the actual channels.

 

[jimfisheye]

Sure, object elements instead of "channel elements". That get rendered on the fly to the available speaker array. And if that speaker array includes height channels, any audio directed to them gets muted by Apple software if your connected device is not recognized on the white list. (I've said "black list" before but it's actually a white list. This is also how they block the compatible computer models from loading a newer OS when they draw the planned obsolescence line.)

The fact that I can turn this on/off like a switch - and there it is working with the workaround - tells me this is purely software spoofing. The hardware obviously works - because here it is working!

I hesitate to suggest this is someone screwing up. Apple and Dolby just don't know what they're doing and screwed the whole thing up? And that screw up just happens to force people to run out and buy new hardware when they can't figure out the software? Doubt it.

These are smart crafty people! Atmos is a crafty system and it's just unfortunate they dialed up the greed to this level. It just makes it looks broken to the average user.

Sorry, just mostly ranting!
But my ultimate point is there's a software solution here somewhere that's worth pursuing! I'm talking through this in case it leads to a clue for someone.

 

[LuvMyQuad]

Sure, object elements instead of "channel elements". That get rendered on the fly to the available speaker array. And if that speaker array includes height channels, any audio directed to them gets muted by Apple software if your connected device is not recognized on the white list. (I've said "black list" before but it's actually a white list. This is also how they .

I don't understand why you keep repeating this fallacy. Nothing gets muted. No part of the signal is lost. Height info just doesn't get re-directed. It stays in the 7 standard channels.

 

[sjcorne]

I don't understand why you keep repeating this fallacy. Nothing gets muted. No part of the signal is lost. Height info just doesn't get re-directed. It stays in the 7 standard channels.

Yes! Especially puzzling as it's so easy to verify. Hopefully I can put a pin in this once and for all...

I mentioned this in another thread, but at around three-and-a-half minutes into the song "Design" (from Gentle Giant's Interview) there's a crazy moment where everything drops out of the mix except for the hocketing vocals in the height speakers. This is a must-check-out song for anyone with an Atmos system.

I ripped the TrueHD audio from the Blu-Ray to 7.1 FLAC using DVD-Audio Extractor (which obviously does not contain the Dolby Atmos Renderer software) and those vocals are 100% still audible, at the same level and relative position (front heights to fronts, rear heights to rears). If the height information was really being muted, you'd see total silence in the highlighted area below.

 

[pti]

Passthrough is coming:

https://www.macrumors.com/2024/07/03/macos-sequoia-supports-hdmi-passthrough/

 

[jimfisheye]

If you try to play or rip an Atmos encoded file with an app that doesn't have the Atmos decoder, you get an 8 channel file with the object audio baked in. (Defaults to TrueHD decoding. At least with recent-ish software.) Nothing to mute here because it's already a folded down 8 channel result.

Play > 8 channel audio in any media player that is not the Dolby reference player or the Music app with an "approved" Atmos device connected and the height channels are muted. Pull up VOX media player with a 12 channel wavpack file with a 7.1.4 mix. Straight 12 channel audio with no encoding. Channels 9-12 are silenced. You can 'trick' the system with the default 'no selection' to work around this as I've described. You can do this going back to at least High Sierra too and do Atmos with older MacOS if it's convenient.

Passthrough depends on the media player and is still a workaround for using a decoding AVR. The problem is the streaming Atmos will either be blocked if no approved device detected or it will get decoded and then there's nothing to pass through anymore. Maybe try the same default 'no selection' trick with this if something is still blocking it? I've been HTPC for 30 years and avoid HDMI connections for audio so I have no way to test such a thing. The fuckery Apple is up to is obviously playing a part in this because passthrough should simply be passthrough and more on the media player than the OS. The OS thinks it's pushing audio data - this was a workaround trick to begin with.