HDMI Passthrough does not work on Sequoia using Atmos capable AVR.

[PeterMack]

I have recently upgraded to Sequoia and it mostly went ok. I am connecting to my monitor via a Denon AVR-X3600H receiver, and under Windows as soon as I start playing back an Atmos track using Media Player it immediately switches to Atmos, and plays back in 7.1.4 layout. So the connection, the cables work. But on macOS, it always stays in 7.1 mode, metadata is not streamed to the AVR for the height channels. I have passthrough enabled in both Apple TV and in Apple Music, and I am able to play back Atmos using an audio interface with 16 outputs.
I have a Radeon Vega 64 card, it should be capable of playing back HDMI audio with metadata.
Has anyone experienced anything similar?

 

[EliteMacx86]

I have recently upgraded to Sequoia and it mostly went ok. I am connecting to my monitor via a Denon AVR-X3600H receiver, and under Windows as soon as I start playing back an Atmos track using Media Player it immediately switches to Atmos, and plays back in 7.1.4 layout. So the connection, the cables work. But on macOS, it always stays in 7.1 mode, metadata is not streamed to the AVR for the height channels. I have passthrough enabled in both Apple TV and in Apple Music, and I am able to play back Atmos using an audio interface with 16 outputs.
I have a Radeon Vega 64 card, it should be capable of playing back HDMI audio with metadata.
Has anyone experienced anything similar?

Never tried actually. Was it working prior to Sequoia upgrade?

 

[PeterMack]

Never tried actually. Was it working prior to Sequoia upgrade?

No, this is a new feature added to Sequoia.

 

[EliteMacx86]

No, this is a new feature added to Sequoia.

Oh, right right. Try to remove the MIDI Settings and then re-create.

 

[PeterMack]

Oh, right right. Try to remove the MIDI Settings and then re-create.

I don't create anything, the audio device for HDMI connections appear automatically, just like before. The change would be that Apple now supposed to detect if the connected device is capable of handling metadata embedded into the HDMI audio bitstream, and if yes then pass on this bitstream from audio sources that support it. Officially the HDMI audio only supports 8 audio channels and this does not change with this new feature either, the extra channels are transmitted as metadata.
I've been looking at the system logs, and it seems that there may be a mismatch between the audio stream formats my Denon receiver reports as being capable of and what Apple expects, it is not clear exactly why, the error messages are not that detailed. It seems to me that this may be an issue with either the Denon firmware, or with Apple's new feature. But since I have not even seen anyone anywhere who tried running a similar configuration on Intel silicon (or with a third party graphics card of a hackintosh), the very first thing I would like to confirm is that if it works at all for anyone with a different AV receiver, or a different graphics card. So far I've only seen YouTube videos and articles reviewing the feature on Apple silicon with builtin HDMI ports.
The feature seems to be working - incorrectly thought -, when I use Apple TV (I mean the Apple TV app on macOS). If you look at the channel/bitrate/sampling frequency selection dropdown in Audio Midi Setup dialog, it automatically switches from "8 channel 24 bit 48kHz" to "Encoded Digital Audio 48kHz" when I start playing anything with Apple TV, and you can't change this until you close the play window of Apple TV. This is exactly how the HDMI passtrhrough is supposed to work, and on Windows 11 it is very similar to this. The problem is that when I look at my AV receiver's codec information, it is still only streaming Dolby Digital+ with 8 channels, instead of Dolby Atmos, and it shows that only the 8 bed channels are received. On Windows 11 this codec information changes to Dolby Atmos, and all 12 channels are listed as input. With Apple Music I don't even see this switch to "Encoded Digital Audio" format, so it does not trigger the passthrough feature at all.

 

[EliteMacx86]

I don't create anything, the audio device for HDMI connections appear automatically, just like before. The change would be that Apple now supposed to detect if the connected device is capable of handling metadata embedded into the HDMI audio bitstream, and if yes then pass on this bitstream from audio sources that support it. Officially the HDMI audio only supports 8 audio channels and this does not change with this new feature either, the extra channels are transmitted as metadata.
I've been looking at the system logs, and it seems that there may be a mismatch between the audio stream formats my Denon receiver reports as being capable of and what Apple expects, it is not clear exactly why, the error messages are not that detailed. It seems to me that this may be an issue with either the Denon firmware, or with Apple's new feature. But since I have not even seen anyone anywhere who tried running a similar configuration on Intel silicon (or with a third party graphics card of a hackintosh), the very first thing I would like to confirm is that if it works at all for anyone with a different AV receiver, or a different graphics card. So far I've only seen YouTube videos and articles reviewing the feature on Apple silicon with builtin HDMI ports.
The feature seems to be working - incorrectly thought -, when I use Apple TV (I mean the Apple TV app on macOS). If you look at the channel/bitrate/sampling frequency selection dropdown in Audio Midi Setup dialog, it automatically switches from "8 channel 24 bit 48kHz" to "Encoded Digital Audio 48kHz" when I start playing anything with Apple TV, and you can't change this until you close the play window of Apple TV. This is exactly how the HDMI passtrhrough is supposed to work, and on Windows 11 it is very similar to this. The problem is that when I look at my AV receiver's codec information, it is still only streaming Dolby Digital+ with 8 channels, instead of Dolby Atmos, and it shows that only the 8 bed channels are received. On Windows 11 this codec information changes to Dolby Atmos, and all 12 channels are listed as input. With Apple Music I don't even see this switch to "Encoded Digital Audio" format, so it does not trigger the passthrough feature at all.

Never tested that so no idea. If the GPU is activated properly and the Audio, it should be working.

 

[PeterMack]

Never tested that so no idea. If the GPU is activated properly and the Audio, it should be working.

Here are some verbose log messages I'm getting from the TV app:

default 20:53:01.068552+0100 TV <<HLS-FASB>> fasb_log: [0x600001377020:I/WQ.01]
<FigAlternate(326):[0x7ff1bd281db0] [Peak/Avg 24158025/14647904] [3840x1606] [AudioGroup audio-stereo-160_vod-ap-aoc.tv.apple.com] [SubtitleGroup subtitles_vod-ap-aoc.tv.apple.com] [dvh1.05.06,mp4a.40.2] [VideoRange PQ] [HDCP Type1] [FrameRate 23.976] [Pathway ap] [StableID 678b1e72a...0ea338d]>
<FigAlternate(328):[0x7ff1bd2821d0] [Peak/Avg 24300789/14864989] [3840x1606] [AudioGroup audio-ac3_vod-ap-aoc.tv.apple.com] [SubtitleGroup subtitles_vod-ap-aoc.tv.apple.com] [ac-3,dvh1.05.06] [VideoRange PQ] [HDCP Type1] [FrameRate 23.976] [Pathway ap] [StableID 678b1e72a...0ea338d]>
<FigAlternate(330):[0x7ff1bd2825f0] [Peak/Avg 24365213/14928993] [3840x1606] [AudioGroup audio-atmos_vod-ap-aoc.tv.apple.com] [SubtitleGroup subtitles_vod-ap-aoc.tv.apple.com] [ac-3,dvh1.05.06,ec-3] [VideoRange PQ] [HDCP Type1] [FrameRate 23.976] [Pathway ap] [StableID 678b1e72a...0ea338d]>
default 20:53:01.068574+0100 TV <<HLS-FASB>> fasb_log: [0x600001377020:I/WQ.01]
<FigAlternate(332):[0x7ff1bd282a10] [Peak/Avg 30351718/24010827] [3840x1606] [AudioGroup audio-stereo-160_vod-ap-aoc.tv.apple.com] [SubtitleGroup subtitles_vod-ap-aoc.tv.apple.com] [hvc1.2.20000000.H150.B0,mp4a.40.2] [VideoRange PQ] [HDCP Type1] [FrameRate 23.976] [Pathway ap] [StableID a1902245a...cc7b884]>
<FigAlternate(334):[0x7ff1bd282e30] [Peak/Avg 30494482/24227912] [3840x1606] [AudioGroup audio-ac3_vod-ap-aoc.tv.apple.com] [SubtitleGroup subtitles_vod-ap-aoc.tv.apple.com] [ac-3,hvc1.2.20000000.H150.B0] [VideoRange PQ] [HDCP Type1] [FrameRate 23.976] [Pathway ap] [StableID a1902245a...cc7b884]>
<FigAlternate(336):[0x7ff1bd283250] [Peak/Avg 30558906/24291916] [3840x1606] [AudioGroup audio-atmos_vod-ap-aoc.tv.apple.com] [SubtitleGroup subtitles_vod-ap-aoc.tv.apple.com] [ac-3,ec-3,hvc1.2.20000000.H150.B0] [VideoRange PQ] [HDCP Type1] [FrameRate 23.976] [Pathway ap] [StableID a1902245a...cc7b884]>
default 20:53:01.068603+0100 TV <<HLS-FASB>> fasb_log: [0x600001377020:I/WQ.01]
<FigAlternate(338):[0x7ff1bd283670] [Peak/Avg 30364364/24282367] [3840x1606] [AudioGroup audio-stereo-160_vod-ap-aoc.tv.apple.com] [SubtitleGroup subtitles_vod-ap-aoc.tv.apple.com] [dvh1.05.06,mp4a.40.2] [VideoRange PQ] [HDCP Type1] [FrameRate 23.976] [Pathway ap] [StableID 134740b2b...8de0f2b]>
<FigAlternate(340):[0x7ff1bd283a90] [Peak/Avg 30507128/24499452] [3840x1606] [AudioGroup audio-ac3_vod-ap-aoc.tv.apple.com] [SubtitleGroup subtitles_vod-ap-aoc.tv.apple.com] [ac-3,dvh1.05.06] [VideoRange PQ] [HDCP Type1] [FrameRate 23.976] [Pathway ap] [StableID 134740b2b...8de0f2b]>
<FigAlternate(342):[0x7ff1bd283eb0] [Peak/Avg 30571552/24563456] [3840x1606] [AudioGroup audio-atmos_vod-ap-aoc.tv.apple.com] [SubtitleGroup subtitles_vod-ap-aoc.tv.apple.com] [ac-3,dvh1.05.06,ec-3] [VideoRange PQ] [HDCP Type1] [FrameRate 23.976] [Pathway ap] [StableID 134740b2b...8de0f2b]>
}
LOG COMPLETE
default 20:53:01.103548+0100 TV <<HLS-FASB>> fasb_log: [0x600001377020:I/WQ.01]
//////8PAP///////////////////z8= 170 ->170: [FigSimpleAlternateFilter <SupportedAudioFormat:0x600000b4c8c0> priority:1000 ac3IsDecodable:YES ec3IsDecodable:YES atmosIsDecodable:NO, ac3CanPassthrough:YES ec3CanPassthrough:NO, atmosCanPassthrough:NO]
//////8PAP///////////////////z8= 170 ->170: [FigSimpleAlternateFilter <SuppressDoVi5Stereo:0x600000a60850> priority:1000]
//////8PAP///////////////////z8= 170 ->170: [FigSimpleAlternateFilter <MediaValidationForStereoVideo:0x600000a60690> priority:1000]
//////8PAP///////////////////z8= 170 ->170: [FigSimpleAlternateFilter <SuppressDoVi20Mono:0x600000a60770> priority:1000]
//8AAP8PAP///////////////////z8= 170 ->154: [FigSimpleAlternateFilter <SupportedVideoRange:0x600000a976b0> priority:1000 mode:[SDR]]
default 20:53:01.103584+0100 TV <<HLS-FASB>> fasb_log: [0x600001377020:I/WQ.01]
AAAAAP8PAP///////////////////z8= 138 ->138: | |--> Leaf: [FigSimpleAlternateFilter <EligibleLosslessAudio:0x600000b01490> priority:760]
AAAAAP8PAP///////////////////z8= 138 ->138: | |--> Leaf: [FigSimpleAlternateFilter <ImmersiveAudioPreference:0x600000b016c0> priority:760 capability:Unknown]
AAAAAAwDAAzDMAzDMAzDMAzDMAzDMAw= 138 -> 46: | |--> Leaf: [FigSimpleAlternateFilter <PreferredAudioFormat:0x600000b017a0> priority:750 preferredFormat:Maximum preferredMixableNumberOfChannels:8 ac3CanPassthrough:YES ec3CanPassthrough:NO atmosCanPassthrough:NO preferLossyEncodings:YES sampleRateContraints:<channel count 2: max sample rate 48000.000>, <channel count 8: max sample rate 192000.000>]
default 20:53:01.103605+0100 TV <<HLS-FASB>> fasb_log: [0x600001377020:I/WQ.01]
| |--> Leaf: [FigSimpleAlternateFilter <PreferredAudioFormat:0x600000b018f0> priority:750 preferredFormat:Maximum preferredMixableNumberOfChannels:2 ac3CanPassthrough:YES ec3CanPassthrough:NO atmosCanPassthrough:NO preferLossyEncodings:YES sampleRateContraints:<channel count 2: max sample rate 48000.000>, <channel count 8: max sample rate 192000.000>]
| |~~> Fall: [FigAlternateFilterTreeFilter <StereoAudioFilterTree:0x600003952d80> priority:760]
| |--> Leaf: [FigSimpleAlternateFilter <EligibleLosslessAudio:0x600000b01ce0> priority:760]
default 20:53:01.103621+0100 TV <<HLS-FASB>> fasb_log: [0x600001377020:I/WQ.01]
| |--> Leaf: [FigSimpleAlternateFilter <ImmersiveAudioPreference:0x600000b01730> priority:760 capability:Unknown]
| |--> Leaf: [FigSimpleAlternateFilter <PreferredAudioFormat:0x600000b01c00> priority:750 preferredFormat:Maximum preferredMixableNumberOfChannels:2 ac3CanPassthrough:YES ec3CanPassthrough:NO atmosCanPassthrough:NO preferLossyEncodings:YES sampleRateContraints:<channel count 2: max sample rate 48000.000>, <channel count 8: max sample rate 192000.000>]
AAAAAAwDAAzDMAzDMAzDMAzDMAzDMAw= 46 -> 46: [FigSimpleAlternateFilter <FrameRateBucketCap:0x600000a932c0> priority:700 framerateBucketCap:30fpsBucket]
AAAAAAwDAAzDMAzDMAzDMAzDMAzDMAw= 46 -> 46: [FigSimpleAlternateFilter <ResolutionCap:0x600000a97950> priority:700 3840x2160]
default 20:53:01.461899+0100 TV AQAC3IONode.cpp:175 AQAC3IONode(0x600001063180): can not find AC-3/EC-3/ATMOS stream on device
default 20:53:01.471847+0100 TV AQAC3IONode.cpp:175 AQAC3IONode(0x600001066d90): can not find AC-3/EC-3/ATMOS stream on device
default 20:53:01.478960+0100 TV AQAC3IONode.cpp:175 AQAC3IONode(0x600001066d90): can not find AC-3/EC-3/ATMOS stream on device

 

[PeterMack]

The EDID definitely supports E-AC3 JOC that is needed by Apple passthrough, at least that's what all the EDID readers are telling me. Maybe something is missing from my EDID that would be needed by macOS?