TrueHD Atmos

I’ve been pouring over threads about this today and can’t quite fully understand what’s going on.

I read “Infuse will read the TrueHD track and decode it to PCM. Atmos metadata is stripped out because the AppleTV doesn’t support bitstreaming which is required for TrueHD with atmos.”

So what exactly is the Atmos metadata? Does it still send a 7.1 signal or does it mean it’s stripped back to 5.1?

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It’s 7.1 if the original source track was 7.1. The metadata is the object oriented stuff that contains info for height speakers.

As mentioned above, 7.1 output is supported if the original track is 7.1.

The one thing that gets lost with TrueHD is the Atmos metadata. This won’t affect the actual audio track (you’ll still get full 5.1 or 7.1), but will affect placement of some sounds (EG overhead sounds).

Some general info on the audio options available in Infuse on the Apple TV can be found here.

I’m also confused. I have an AppleTV 4K, 2 HomePods and Infuse (life-long, love it).

I’ve seen that Infuse supports “theatre mode” which I thought might include TrueHD: Play audio in Dolby Atmos or surround sound on your Apple TV - Apple Support

AppleTV and the Homepods support Atmos including the height info, it sounds great when using Disney+ (for example).

Is it possible to get the same experience with Infuse? Should I look at using a particular audio codec?

If there is a software limitation, is that caused by Apple, or could something be added to Infuse?

What are the chances of having the same, full experience in Infuse? Including the height data and everything else that already sounds great in AppleTV+, Disney+, Netflix etc?

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There’s a massive thread that will answer most of your questions here

The last several pages will probably get most answers. :wink:

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Thanks a lot.

However, it’s still not clear unfortunately as this thread adds to the confusion and is unfortunately closed: Infuse and Homepod home theater - sound issues

It isn’t clear if spatial audio is supported with HomePod and with which codecs that can be achieved.

For example, this Theatre Mode, will it work with TrueHD?

AppleTV does not support spatial audio. You can get atmos on your HomePod just like in Netflix if the file you are playing contains a Dolby Digital Plus Atmos soundtrack (common with webrips). If the soundtrack is TrueHD with atmos you will only get regular 5.1/7.1 uncompressed PCM.

TrueHD Atmos support is dependent on Apple supporting it. There is no magic that any app developer can do. Audio cannot be converted from TrueHD Atmos to Dolby Digital Plus Atmos.

If you want TrueHD Atmos the only way to get it is with an Android media player and a receiver or soundbar that supports TrueHD Atmos via bitstreaming.

I understand that including the Atmos metadata (in TrueHD tracks) to the uncompressed PCM sound that is sent from the AppleTV is impossible due to the AppleTV itself, tvOS, etc.

But I’m curious which track do you guys prefer ?

  1. Dolby TrueHD 7.1 (uncompressed, much higher bitrate but without atmos)
  2. Dolby Digital Plus (usually 5.1, compressed as hell but with atmos).

Option 1 sounds best (much crisper) for me on my LG SK9Y soundbar.

Depends on the quality of the media, if I am watching high quality 4K Movie content TrueHD, if I am watching UHD TV for instance, I am OK with lossy.

Looks like / eARC has been enabled on the 2nd gen 4K Apple TV, possibly passthrough also.

Unfortunately, seems to be only supported on the discontinued HomePod, Apple is such a mess on their home strategy.

I don’t think so, looks like they are just using the homepod as an example, fingers crossed.

Nope, says right on the page from Apple linked above,

HomePod mini speakers aren’t supported.

Who is talking about homepod minis?

The requirements section of the support article is pretty clear… Just in case you have any further doubt…

EARC has nothing to do with TrueHD as the bandwidth requirements through hdmi are more than enough with the current 1st Gen atv 4K. This is only useful for playback of TV audio through an Apple TV to airplay connected speakers.


TrueHD is not supported over ARC, only eARC which is a hdmi 2.1 feature not on older ATV, so I wouldn’t say that’s completely true. They might be supporting reverse bitstream of audio at least.

Does not require a new hdmi cable to support this though

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Is it possible to transcode TrueHD to E-AC-3 and keep Atmos meta and then bitstream? So for TrueHD Atmos content we could still listen the height channel.

Nope not possible. Best you can do is do a rip and replace on the audio with studio encoded lossy atmos from webrips.

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