Someone got Blu-ray's Dolby Atmos TrueHD sound working on the Apple TV 4K, through quite the hack

For now you need to build the feature yourself on a Mac Native Player delivers similar audio but isn't open source Proposed as an extension to the Nuvio media player A clever developer has come up with a way to deliver lossless Dolby TrueHD movie soundtracks, complete with Dolby Atmos effects, to home theater speakers from the third-gen Apple TV 4K.

The Apple TV only officially supports Dolby Digital Plus, which is the more compressed Dolby audio codec used by streaming services to reduce the amount of data used, while Dolby TrueHD is used on Blu-rays where bandwidth isn't a problem.

So it makes sense for the Apple TV 4K to only use Dolby Digital Plus, since it's a streaming device — but that doesn't stop the enthusiasts from wanting the flexibility of playing files with TrueHD audio on their devices.

The system that Reddit user Agathorpt used to deliver Dolby TrueHD through the Apple TV 4K requires not actually delivering it in TrueHD at all, but converting it to other formats, converting the Dolby Atmos positional data into other formats too, then recombining them in a format that the Apple TV 4K can deliver, but in a higher quality.

How they got TrueHD Atmos on the Apple TV 4K As mentioned above, the audio takes a bit of a journey here.

The path is: TrueHD Atmos → decoded audio + timed object metadata → fixed 9.1.6 speaker render → APAC → native tvOS playback.

APAC is Apple's Positional Audio Codec, and while it's not truly lossless (the source audio, TrueHD, is a lossless format but APAC is not) the consensus is that the results here are really impressive.

Basically, the system decodes the audio and the 3D Atmos positioning data separately, creates a new audio system where the Atmos effects are mapped to a 9.1.6-channel speaker configuration, then converts that to Apple's own proprietary spatial audio codec , which can then be played by the Apple TV 4K.

The goal was to replicate the audio functionality of a closed-source app called Native Player with an open-source alternative because "keeping the implementation closed… leaves everyone dependent on that vendor for fixes and future support," Agathorpt says.

"Other players can't reuse or improve that code, and the community can't independently inspect how it handles the audio." Apps such as Native Player support TrueHD Atmos but they aren't open source (Image credit: Native Development) "The spatial audio has been working amazingly well for me," Agathorpt says .

"It sounds excellent on my setup." Other redditors have tried the same software and are reporting great results too.

In order to copy what Agathorpt has created, you'd need several things: a Mac; Apple's Xcode development software; and your own Apple development account to sign an app: the full steps they went through are detailed here .