macOS Sequoia Supports HDMI Passthrough for Dolby Atmos Content

[LelandHendrix]

I think the Apple TV supports that already?

Yeah I have no idea what the end of the OP meant when mentioning TvOS. Dolby Atmos and Audio of multiple formats is there has been there a few generations.

 

[Jus711]

Thats correct. Almost all streaming players decode in the player instead of passing the audio through. They do this to support added audio features. The very latest Fire TV revision will passthrough DTS and TrueHD but it breaks Alexa. Other audio formats are decoded and not passed through. All formats are decoded in the player in older versions of the Fire TV. The Apple TV has the same issue. It has audio features, including most of Control Center, that simply won't work unless the audio is decoded first and not passed through. The Shield will pass through audio, but it has limited audio features and thus doesn't have any audio features that require the audio to be decoded in the player.

Yeah the newest fire tv cube will do it through Kodi in my testing but the implementation is a little wonky and it’s only the Cube 3 from what I understand. I had a Xiaomi Mi Box years ago that would do it but Android 8 I believe broke that functionality.

 

[Jus711]

Xbox and PlayStation also support bit streaming but I think that’s only for the Blu-ray player app (at least on PlayStation, Xbox might allow that for other apps, can’t recall).

They aren’t dedicated streaming devices but I don’t think that helps the case for devices designed to stream.

Yes I have a ps5 and it’s only for Blu Rays

 

[Jus711]

Yeah I have no idea what the end of the OP meant when mentioning TvOS. Dolby Atmos and Audio of multiple formats is there has been there a few generations.

Not exactly, it supports lossy Atmos, not lossless HD audio like Dolby TrueHD or DTS HD-MA, it can’t decode those or send the unencoded version for the receiver to decode which is what passthrough would allow.

 

[jaster2]

My biggest headache with multi-channel playback from Macs via HDMI is how HDCP is implemented and the way the Audio /Midi app mis-configures downstream devices. It's a real hassle in some installations but it doesn't appear that Apple is working on making it work better. It would be great if this new feature helped solve this but it doesn't look like it would.

 

[poematik13]

Maybe they could fix external monitor shenanigans we’ve been dealing with for ages on MBPs, like the inability to disable a screen with software settings, and remember external display setup through reboots.

the biggest annoyance for me is if you turn an external monitor off, the “screen” is still there and your windows are all lost in that area and the cursor still goes there lol. you have to physically unplug the laptop to use just the built in display

 

[reallynotnick]

Yeah I have no idea what the end of the OP meant when mentioning TvOS. Dolby Atmos and Audio of multiple formats is there has been there a few generations.

It’s not passthrough, it’s decoded into LPCM (LPCM+MAT in DD+ Atmos’s case) and sent to the device. And as already pointed out it’s just lossy DD+ not Dolby TrueHD.

 

[mastercheif91]

This is almost certainly for E-AC3 passthrough, so don’t get your hopes up lossless fans.

 

[mogga71]

I think the Apple TV supports that already?

Nope.

In macOS Sequoia, several Apple apps have gained a new HDMI Passthrough feature that enables a Mac to send an unaltered Dolby Atmos audio signal to a connected AV receiver or soundbar.

The new functionality appears in various places in macOS 15, including Apple's TV, Music, and QuickTime Player apps. Apple says turning on the option lets users "Play supported audio in Dolby Atmos and other Dolby Audio formats using HDMI Passthrough when connected to a supported device."

The feature is likely to be welcomed by users who connect their Mac to an external device that supports Dolby Atmos, such as an AV receiver or soundbar. When conected via HDMI cable, the device will be able to decode and output the full immersive Dolby Atmos audio as it was meant to be experienced by the creators, while sending any accompanying video signal to a connected TV.

It's unclear whether this option will be included in tvOS 18, but given that Apple has made it a system-wide feature in macOS Sequoia, there is a good chance we will see it come to Apple TVs in a future update. Both macOS Sequoia and tvOS 18 are currently in developer beta, with public betas expected later this month, followed by a general release in the fall.

Article Link: macOS Sequoia Supports HDMI Passthrough for Dolby Atmos Content

Ok so as things stand the Apple TV only supports compressed Atmos ... not the lossless variety. If this announcement means they are opening up the AppleTV to lossless audio formats then this may mean that Infuse have finally got their wish granted after they launched a petition to get lossless supported. This means that Infuse could play a 4k bluray rip which contains lossless Atmos and it would play uncompressed...which is brilliant.

However it means that Infuse will then be a superior method of playing movies etc. than purchasing them from Apple ... as they would presumably still be compressed audio due to size during streaming.

The BIG game changer however would be if Apple started allowing movies to be downloaded to AppleTV and played with lossless audio. It would literally be the Kaleidoscope killer.

 

[mikeb13]

We need someone with a Mac running the latest beta to connect it to a AVR via HDMI and play a blu ray rip/remux with lossless audio and see what audio format the AVR plays.

 

[lindijones]

Nope.

Ok so as things stand the Apple TV only supports compressed Atmos ... not the lossless variety. If this announcement means they are opening up the AppleTV to lossless audio formats then this may mean that Infuse have finally got their wish granted after they launched a petition to get lossless supported. This means that Infuse could play a 4k bluray rip which contains lossless Atmos and it would play uncompressed...which is brilliant.

However it means that Infuse will then be a superior method of playing movies etc. than purchasing them from Apple ... as they would presumably still be compressed audio due to size during streaming.

The BIG game changer however would be if Apple started allowing movies to be downloaded to AppleTV and played with lossless audio. It would literally be the Kaleidoscope killer.

Just a quuestion:
I do get the Dolby Atmos sound out of an Apple TV when connected into a AV receiver, or not?

Is this change a difference in the used codecs/compressions then?

 

[Jus711]

You’re getting lossy Atmos via Dolby Digital+, not the full uncompressed Dolby True HD with Atmos.

 

[lindijones]

View attachment 2394162 You’re getting lossy Atmos via Dolby Digital+, not the full uncompressed Dolby True HD with Atmos.

Ah ok. Thx.

But then another question:

Do i get Atmos (maybe lossy, but anyway) out of the HDMI port of a Mac at the moment?

And btw: is the Apple Music Atmos lossless?

 

[mogga71]

This is almost certainly for E-AC3 passthrough, so don’t get your hopes up lossless fans.

Surely if it would be doing PassThrough then why limit it to E-AC3 ... so you mean it would actually go to the trouble of compressing a lossless track ... I doubt it.

We are all focusing on movies here but probably the reason its being added to the Mac first (and maybe only to the Mac) is for sound professionals.

 

[Jim Lahey]

Apple TV desperately needs bitstream out. Until then I can't take it seriously and won't ever buy another until Apple stops treating it like a glorified iPad with HDMI. Sadly I imagine Dolby licensing agreements are in play that mean Apple will never in a million years allow this at the system level because it would enable users to pass unmolested dts audio out to an AVR via the likes of Plex.

 

[rezwits]

Finally a reason to get the MacMini Pro back for the living room TV again! whew cool!

 

[marvin_h]

If this doesn’t come to tvOs I might have make my next ATV purchase be a Mac mini……

If lossless audio comes to the iTunes movie store, I’ll be in Hog heaven.

 

[ryanmp]

One can only dream that this comes to Apple TV, but I'm just not sure that will ever happen.

 

[I am Sampson]

Forgive my ignorance; genuine question… what will this do for appleTV?

I can already play ATMOS audio from it to my amp running 5.2.4 speakers and it is detected by the amp as ATMOS when it is an ATMOS movie. (Although I oddly have to change Apple TV to convert to Dolby digital whenever playing something NOT atmos otherwise it ends up stereo for some reason - that’s annoying).

I care not for atmos from my laptop as in my use case it, well, has no use, but am interested in any potential benefits people are speculating for Apple TV.

 

[HDFan]

The BIG game changer however would be if Apple started allowing movies to be downloaded to AppleTV and played with lossless audio.

A movie .mkv file (not currently supported) can be almost 100 GB in size. Likely a problem with a current maxed out 128 GB Apple TV.

 

[turbineseaplane]

Why is Apple so often implementing basic features that everyone else supports YEARS later?

It's always been their MO

 

[urmaster]

Forgive my ignorance; genuine question… what will this do for appleTV?

I can already play ATMOS audio from it to my amp running 5.2.4 speakers and it is detected by the amp as ATMOS when it is an ATMOS movie. (Although I oddly have to change Apple TV to convert to Dolby digital whenever playing something NOT atmos otherwise it ends up stereo for some reason - that’s annoying).

I care not for atmos from my laptop as in my use case it, well, has no use, but am interested in any potential benefits people are speculating for Apple TV.

It won’t do anything for Apple TV, but as Apple shares a lot of code between their operating systems there may be hope this feature finds its way to Apple TV eventually.

Currently you’re getting lossy eAC3 at the most which can include Atmos. This isn’t the same as the lossless track you find typically as the primary track on a Blu-Ray (TrueHD or DTS-X). The pass through setting seen here on macOS should allow these lossless tracks to work.

 

[mikeb13]

Hopefully once the public beta comes out later this month, someone will test it and let us know what audio is being sent to their AVR.

 

[jbellanca]

This a big one for us  TV users, we’ve been wanting this for years, hopefully it comes over to tvOS 🤞🏾

The Apple TV already supports E-AC3+Atmos, and works on Plex, Infuse, and other players.

I'm HOPING this also means that they'll be supporting Dolby TrueHD+Atmos which is sorely missing on Apple TV.

 

[AdriftAtlas]

Great. Maybe they could also support Display Port MST so you can drive two external monitors from a MacBook (you know, like every other OS on the planet, and like how you can if you run Bootcamp and Windows on the Apple hardware).

Whoa whoa whoa... How else is CalDigit going to sell $400 docks? It may even affect sales of the Apple polishing cloth! We can't have people buying pedestrian MST docks from AliExpress. How dare you blaspheme! /s

My biggest headache with multi-channel playback from Macs via HDMI is how HDCP is implemented and the way the Audio /Midi app mis-configures downstream devices. It's a real hassle in some installations but it doesn't appear that Apple is working on making it work better. It would be great if this new feature helped solve this but it doesn't look like it would.

HDCP on macOS is a nightmare. It fails display validation if you so much as breath. Easier to sail the high seas.