Dolby Atmos does not work properly on tvOS 15 with HomePod

[WonCheol]

Hi. I've been thinking that an updated version of MrMC would be released soon, but now I'm getting frustrated that there is still no new version since tvOS 15 was released on September.

And I've just looked into this community, and surprised that I could not find any article which reports the problem similar to mine.

I use Apple TV4K (original) and HomePod (original) as its audio output. And Dolby Atmos worked fine on tvOS 14, when I setup the audio device of MrMC to multi-channel, while other third-party apps, such as Infuse Pro, does not handle Dolby Atmos audio and transcoded it into stereo.

But after I updated tvOS and HomePod Audio OS to Version 15, MrMC started to mulfunction with Dolby Atmos audio while Infuse Pro started to work fine without stereo-transcoding.

The symptom is like this: when I setup the audio device for MrMC to multi-channel and play a media file with Dolby Atmos audio, only two channel, front left and right, seems to make sound making the entire sound very weird.

I also use Kodi on AppleTV and it just works fine with Dolby Atmos audio, on the latest tvOS and HomePod Audio OS.

[WonCheol]

Update:

I've just come to know that AppleTV does not support Lossless Dolby Atmos, while it supports lossy E-AC3 Dolby Atmos. FIY, the link below:
https://community.firecore.com/t/help-g ... e-tv/16477

The media files that matter for me are indeed TrueHD with Lossless Dolby Atmos audio tracks. In such cases, Infuse transcodes the track into 7.1 channel LPCM audio. Kodi does the same, I guess. And MrMC makes the sound from only 2 channels, dropping out all the others.

I've tried to play a media file with lossy 5.1 channel E-AC3 Dolby Atmos audio, and MrMC plays at least 5.1 channel audio. But it sounds like just 5.1 channel, not Dolby Atmos, while it sounds like Dolby Atmos when it's played by Infuse.

Please find the link below the media file that I've tested:

https://we.tl/qyk3IxvnnM