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Snuupy

macrumors newbie
Original poster
Jun 11, 2022
20
6
Hi guys,

I just tried to play Atmos track from a 4K Remux file (Glory 4K), and the receiver Yamaha RX-V585 is displaying PCM and the input signal is 3.4.1 (7.1), but it is not Atmos. I made the settings on the Macbook in the MIDI menu to output 3.4.1 Atmos and configured the Atmos speakers, but without result.

I am using HDMI 2.1 up to 8K 48Gbps. With the same cable I played Atmos with my ex Nvidia Shield Pro, and now with my 4K player Sony UBP-X800M2.

Is the Macbook Pro M1 capable of outputing Atmos to a receiver?
Image 20.03.23 at 8.34.jpeg
 

Snuupy

macrumors newbie
Original poster
Jun 11, 2022
20
6
It is not a big deal, since I have 4K player, but it is really stupid from Apple to make such an expensive machine, and this machine to not be capable of things that a 200$ TV box can. But Apple...I assume.
 

Snuupy

macrumors newbie
Original poster
Jun 11, 2022
20
6
No, the Nvidia is with the same port and it's playing Atmos, DTS:X, Dolby Vision... https://www.nvidia.com/en-us/shield/shield-tv-pro/

Just apple doesn't care, because the mass of people are using Apple Music, Apple TV +, but the streaming services are far away as audio quality/video quality from a 4K movie. I'm collecting 4K movies, but if there is a new movie, I prefer to download it first and to see if it's good and then buy it.
And one other thing, yesterday I downloaded the The last of the mohicans, because I didn't found it in Apple TV+, HBO Max or Bravia Core (dedicated streaming service from Sony), it happens often with those streaming services, they are adding/removing movies.

However, obviously the "Pro" model is not able to do "Pro" things fully.
I'm using the M1 for video editing/photo editing and it's a great machine overall.
 

Stuey3D

macrumors 6502a
Jul 8, 2014
832
951
Northamptonshire, United Kingdom
So my findings with this are via my Anker MacBook Air specific dock I can do 4k30 or 1080p120Hz and on the audio front it defaulted to 7.1 PCM Indicated on the AV Receiver as PCM 3/4/0.1

Now in the Midi settings I have 8 channels 16bit 48Khz to play with, now this gives me the option of 5.1.2 Atmos in the Midi settings, now here is where it gets weird.
If you select 5.1.2 Atmos in the Midi settings it just outputs as PCM 3/4/0.1 and the height channels which you select as channels 7&8 are just added into the rear speakers of my 5.1 base layer as if it were traditional 7.1 downmixed to 5.1 and the 2 heights are completely missed out. macOS does not encode anything in Atmos and just outputs the raw 7 channels direct to the AV Receiver which is no good unless you were to change your AV Receiver to have 7.1 with rear selected as your speaker config and then put them in the ceiling, but this setup will then not work for everything else.

Microsoft on the other hand have worked with Dolby direct and for the Xbox and Windows you download the Dolby access app and then enable Dolby Atmos for Home Theatre and then what it does is outputs as PCM but with the Atmos flag which correctly sets the AV Receiver to use the heights properly, which is what macOS is failing to do as it doesnt send the Atmos flag with the output.

The other most annoying thing is that on Windows you can set apps like VLC to use Bitstream out which will send things like Atmos/DTS:X/Dolby True HD/Dolby Digital/DTS out to an AV Receiver directly which then bypasses all OS level sound processing and the AV Receiver can then decode stuff as it sees fit, on macOS this option only half works.

VLC set to directly output to the TV Encoded Output (TV has E:ARC and this will passthrough as tested with my Legion 5) on macOS the following happens

Dolby True HD = PCM 3/4/0.1
Dolby True HD + Atmos = PCM 3/4/0.1 no flag sent thus no heights
DTS:X = DTS 3/2/0.1 but no X so again no heights
Dolby Digital + Atmos (the same all streaming services use) = PCM 3/4/0.1 no Atmos Flag again no heights.

On my Receiver (Yamaha RXV583) if all is working as it should you should see.

For Atmos:
PCM/Atmos (Apple TV/Xbox/Windows use this by default)
Dolby True HD/Atmos
Dolby Digital+/Atmos

For DTS:
DTS:X

If those modes are working as they should the minute the Receiver receives the Atmos or X flag it will no longer list separate channels on the signal info page as these are object based and not channel based, this is something I have not been able to get working on macOS.
 
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systematic92

macrumors newbie
Dec 27, 2015
21
2
Ive got the following setup

Samsung S95B (will probably upgrade to LG G3)
Samsung Q990C
Hard drive full of remux MKVs at full 50-100GB sizes embedded with Atmos, DTSX, Dolby Vision and HDR10+

I've tried every effing way to play my files with mixed results and the soundbar always displaying Multi Channel PCM instead of it saying ATMOS 7.1 etc.

Now a side line finding. Did you also know the M1 Pro doesn't output 4K HDR but instead 4K SDR? Yep that is true andmy tests were finally confirmed by this blurb here:

-----START-----

https://www.idownloadblog.com/2021/10/21/macbook-pro-hdmi-limitations/

What are the limitations of my MacBook Pro’s HDMI port?
Both the 14-inch MacBook Pro and the 16-inch version have one HDMI port that conforms to the HDMI 2.0 specification rather than the newer HDMI 2.1.
According to the technical specifications on Apple’s website, this limits you to connecting one external display with 4K resolution at sixty Hertz via the notebook’s HDMI 2.0 port. To be perfectly clear, this is standard dynamic range (SDR) we’re talking about as HDMI 2.0 doesn’t support high dynamic range (HDR) content.

-----END-----

And yes I have tested this. When I connect the Macbook to my 4K 120hz port on the TV via a HDMI 2.1 cable, my TV refuses defaults to BT.1886 Gamma (SDR) and the option for ST.2084 (HDR) is greyed out. This again is the limitation of the action port on the macbook being 2.0.

I've given up on the Macbook and am going to try a NVIDIA Shield Pro and see what results I achieve.
 

Stuey3D

macrumors 6502a
Jul 8, 2014
832
951
Northamptonshire, United Kingdom
HDMI 2.0 can definitely do HDR as HDR was a thing before HDMI 2.1

As long as the port has the required 18Gb/s bandwidth required for 4K60 then HDR of some form should be able to be activated unless Apple has really decided to nerf the port for some reason.

The colour space you need is rec/bt.2020 I’ve never seen ST.2084 before so that could be the issue. That being said I am no expert this is just stuff I’ve seen from my own devices. I also only have a MacBook Air M1 so don’t have an internal HDMI port only dongles but none of my dongles do full 4K60 only 4K30 so no ability to test HDR from my Mac without purchasing other hardware that I don’t require.
 

systematic92

macrumors newbie
Dec 27, 2015
21
2
Thanks for the feedback.

The preset on the MACBOOK was set to APPLE XDR DISPLAY (P3-1600 nits). When connected to the TV with this preset, the TV's picture gamma settings remain defaulted to BT.1886 and ST.2084 was greyed out.

I then changed the preset on the MACBOOK to HDR Video (P3-ST 2084). When connected to the TV with this preset, the TV's picture gamma settings remain defaulted to BT.1886 and ST.2084 was greyed out.

I copied the movie onto an external USB HDD and connected it directly to the TVs USB 2 port and TV picture settings on the TV now defaulted to ST.2084 with BT.1886 greyed out resulting in a much higher quality video than the macbook. HOWEVER, the audio was not as good via USB as it was through mac/HDMI......even though the soundbar displayed the same text - MULTI CHANNEL PCM.

I should add here the MKV file contains two audio tracks 1) ATMOS 7.1 and 2) AC-3 5.1.

I am convinced the USB is failing back to 5.1, which is why the sound is better via the Macbook, which I KNOW is playing the 7.1 track as I've selected it in VLC media player on the MAC. I just the sound bar displayed the text DOLBY ATMOS as opposed to MULTI CHANNEL PCM.

With both tracks, I expect to see MULTI CHANNEL PCM on the soundbar but there's no clear way of me knowing that the USB is presenting the 5.1 track and Laptop is presenting 7.1 track. Well clear way meaning visual stats. I can clearly tell the difference in sound using my ears.

Not sure why the USB is not selecting the 7.1 track by default given that the TV itself is enabled with Dolby Atmos.........but......important note here, with the USB inserted into the TV AND with Dolby Atmos enabled in the TV settings, PASS THROUGH is greyed out. I expect this because PASS THROUGH is only available when you connect an external HDMI device. Since we have a USB HDD, that option is never going to be available. i just figured the TV itself can handle ATMOS so why it doesn't just select the ATMOS track. When the movie is playing, you can go to settings but there is no option for selecting multiple audio tracks, which makes me believe AC- 5.1 is the only one being sent from USB.

In summary, both methods (MAC/HDMI and USB HDD) show MULTI CHANNEL PCM on the soundbar but the mac/HDMI sounds DAY and NIGHT better than the USB HDD. However, video wise, the USB HDD looks DAY and NIGHT better than the mac/HDMI method.
 
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