Dolby Atmos TrueHD Apple TV 4K DIY brings lossless sound with Mac

The Apple TV 4K officially supports Dolby Digital Plus, not Dolby TrueHD. Dolby Digital Plus is the squeezed-down Dolby format that streaming services use to save data. TrueHD is the lossless format pressed onto Blu-ray and 4K Blu-ray discs, where there is plenty of room for it.

For a streaming box, that choice makes sense. The trouble starts when you play your own disc copies, often called remuxes, from a home server. Popular player apps such as Plex and Infuse can decode TrueHD, but they drop the height information that tells ceiling or upfiring speakers what to play. You end up with a flat surround mix.

tvOS also has no audio passthrough. That means an app can’t simply hand the original TrueHD stream to your AV receiver and let the receiver decode it, the way a Blu-ray player does. Apple still hadn’t added passthrough by early November, even with a new Apple TV 4K on the way.

The Reddit user, who posts as Agathorpt, gets around that by never sending TrueHD at all. The soundtrack is pulled apart and rebuilt in a format the Apple TV already understands. In plain steps:

1. The TrueHD Atmos track is decoded into ordinary audio plus timed object data, the notes that say where each sound sits in the room.
2. That object data is used to render the sound to a fixed 9.1.6 speaker layout (nine main speakers, one subwoofer and six height speakers).
3. The result is packed into APAC, Apple’s Positional Audio Codec, which tvOS can play natively.

There’s a catch hidden in the headline promise. TrueHD is lossless, but APAC isn’t, so the sound that reaches your speakers is not a bit-perfect copy of the disc. Agathorpt says the spatial audio sounds excellent on their system, and other Reddit users who tried the code have reported strong results too.

The work leans on other people’s projects. Agathorpt credits a developer known as Superuser404notfound, whose AetherEngine media engine and LibTrueHD object audio decoder do much of the heavy lifting.

This is a build-it-yourself job, not a toggle in Settings. You’ll need:

• A Mac with Apple’s Xcode developer tools installed.
• Your own Apple developer account, so you can sign the app and install it on your Apple TV.
• An Apple TV 4K running tvOS 26 or later. The project was shown on the third-generation model.
• Movie files whose Atmos track is TrueHD at 48kHz.

You also need a receiver or soundbar that can actually play height channels, or the extra effects have nowhere to go. If signing apps in Xcode sounds unfamiliar, this route will be frustrating.

Agathorpt’s stated reason for doing it is openness. A closed-source app called Native Player already offered something similar, and they argued that relying on one company leaves users waiting on that vendor for fixes, while nobody else can reuse or inspect the code. The project has been proposed as an addition to Nuvio, an open-source media player, which would let people use it without building anything. That had not happened at the time of writing.

The closed app Agathorpt wanted to match has since moved ahead. Croatian developer Native IT released Native Player 2.0 for Apple TV 4K on October 27, and it now sends TrueHD Atmos to your receiver without any lossy step.

Here’s the difference. Version 1.0, which first appeared in early September, kept the height effects but turned the sound into a compressed stream capped at 4 Mbps. Version 2.0 decodes TrueHD Atmos on the Apple TV itself and sends the speaker channels over HDMI as uncompressed PCM, wrapped in Dolby’s MAT format. A tester at a home theater site checked it over several days and confirmed that it works.

• You can pick your speaker layout from 5.1.2 up to 9.1.6, or leave it on the default and let the receiver adapt.
• DTS:X tracks are also supported, but they always come out as 7.1.4.
• Video support covers Dolby Vision profiles 5, 7, 8 and 10, plus HDR10, HDR10+ and HLG. Profile 10 uses the AV1 codec, which the app decodes in software on every Apple TV 4K.
• It reads files from a NAS or computer over SMB or WebDAV, and plays MKV, M2TS, MP4 and other common formats.

It still isn’t true passthrough, because your receiver never sees the original TrueHD bitstream; the Apple TV does the decoding and room rendering itself. The app is English-only, needs tvOS 26, and its menus are plainer than Infuse’s.

For most people who only stream, nothing changes. Streaming services deliver their Atmos mixes over Dolby Digital Plus, which the Apple TV already handles.

The people who gain are collectors who keep disc copies on a home server and own a proper Atmos receiver. They now have two choices. The DIY build is free and open, but it takes developer tools and the sound passes through Apple’s lossy APAC format. Native Player is a download from the App Store, keeps the audio lossless, and costs money for the good parts.

The basic app is free, but TrueHD Atmos, DTS:X and Dolby Vision profile 7 titles play only as a preview until you buy Native Player Pro. It’s sold as a yearly subscription or a one-time purchase, both marked as early-adopter prices that end when Plex support arrives. Family Sharing works with it.

Buying the new Apple TV 4K won’t fix this by itself either. Apple announced the fourth-generation model on October 13, and it goes on sale November 13 with hardware AV1 decoding, but still no audio passthrough.