Selenite

Your PC games on the Apple TV, streamed from Sunshine.
Native for tvOS. Low latency, clean frame pacing, up to 4K and 500 Mbps.
Two PCs on one TV in split screen, each side with its own controllers.

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What it is

Selenite is a client for Sunshine, the free, open-source game streaming host for Windows, Linux and macOS. It speaks the same protocol as Moonlight, through moonlight-common-c, but everything around it is built for the Apple TV from scratch: a SwiftUI interface for the Siri Remote, a video path tuned for the Apple TV's display pipeline, and a split screen mode no other client has.

Features

Split screen: two PCs, one TV

Stream two hosts at once, side by side or top and bottom.

• A wizard picks host, game and layout for each side. On the join screen every player points their stick at a side and presses A; the stream starts as soon as one controller is seated, and an empty side streams too and can be joined later.
• Each side gets its own controllers. Controllers that play on neither side wait in a lobby.
• Menu on the Siri Remote opens the split overlay while both games keep running: volume per side, disconnect, quit, swap sides, reassign controllers, end the split.
• A tile on Home starts the last split again with one click.

Selenite runs two independent protocol sessions in one process for this. moonlight-common-c keeps its whole connection state in globals, so it is compiled twice under prefixed symbols (see Architecture).

Frame pacing in three steps

Mode	What it does	Typical cost
Lowest latency	Every frame goes out the moment it is decoded.	Lowest latency, judder whenever the network jitters.
Smooth	Elastic playout on the host's own cadence: a few milliseconds of buffer that stretches by a refresh when a frame comes late and steps back after two calm seconds.	A few milliseconds more than Lowest latency, about half the judder.
Smooth+	Two standing frames of buffer for a busy network.	About 50 ms, steadiest picture on a poor link.

Pacing changes are judged by replaying traces recorded on a real Apple TV, not by feel (see Development).

Picture and sound

• Resolutions from 720p to 4K, or match the TV; 30 or 60 fps, or match the display.
• H.264 and HEVC, bitrates up to 500 Mbps.
• Stereo or 5.1 surround.
• Every setting can be overridden per host, from Settings > Hosts or the host card's long-press menu.

Controllers and the Siri Remote

• Xbox and PlayStation controllers with rumble; touchpad, motion and light bar on DualSense and DualShock 4; Xbox Elite paddles.
• Controller buttons, Start and Select included, always go to the host. Only the Siri Remote controls the stream.
• With the overlay closed, the Siri Remote is the host's mouse: the touch surface moves the pointer, a circle on the outer ring scrolls, click is left, Play/Pause is right.

Hosts

• Sunshine hosts on the network show up on their own (Bonjour) and pair with a PIN. Hosts can also be added by address.
• A paired host that moves to a new IP is followed automatically.
• A sleeping PC is woken with Wake-on-LAN when you pick it (a per-host switch, off by default for virtual network adapters).
• Recently played games across all hosts sit on Home.

Stream stats

Off, Compact (a pill in the corner) or Full: resolution, frame rate, display and stream rate, codec, pacing and bitrate; host, network, decode and display latency and round trip; jitter, and dropped frames split into network loss, client queue drops and pacer drops (overflow and catch-up), plus unrecoverable frames, stalls, missed display refreshes and audio underruns. The Menu overlay always shows the full list, in split screen for both sides.

Languages

26 languages: English, German, French, Spanish, Italian, Dutch, Portuguese (Brazil and Portugal), Danish, Swedish, Norwegian, Finnish, Polish, Czech, Slovak, Hungarian, Croatian, Romanian, Greek, Russian, Ukrainian, Turkish, Japanese, Korean and Chinese (Simplified and Traditional).

Privacy

No accounts, no analytics, no tracking. Selenite only talks to your own hosts; see the privacy policy.

Getting started

1. Install Sunshine on your PC and create a user in its web UI (https://localhost:47990).
2. Open Selenite on the Apple TV. The PC appears on Home; if it does not, use Add host and enter its address.
3. Select it and enter the PIN Selenite shows in Sunshine's web UI under PIN.
4. Pick a game. Menu on the Siri Remote opens the stream overlay.

A wired connection for the Apple TV and the host gives the best results; on Wi-Fi, try Smooth first.

Requirements

• Apple TV with tvOS 26 or later. Apple TV 4K recommended (HEVC, 4K).
• A PC running Sunshine on the same network. Split screen needs two, since one Sunshine host serves one stream at a time.

Building from source

Requirements: Xcode 26 or later, XcodeGen (brew install xcodegen).

git clone --recursive https://github.com/superuser404notfound/Selenite.git
cd Selenite
Scripts/generate-project.sh
open Selenite.xcodeproj

Pick the Selenite-tvOS scheme and an Apple TV or the simulator. project.yml is the source of truth for the Xcode project; regenerate after adding or moving files.

Architecture

Selenite/                 tvOS app: Home, Settings, Stream, Split (wizard, join screen, overlay)
SeleniteKit/              Swift package with everything testable
  Sources/AppCore         app state without UI: settings, hosts, recents, stream and split controllers
  Sources/HostKit         discovery, nvhttp, pairing, Wake-on-LAN
  Sources/StreamKit       video intake, decoding, frame pacing, audio, stats
  Sources/InputKit        controllers, seats, rumble and feedback, the Siri Remote pointer
  Sources/MoonlightCore   Swift bridge to the protocol core
  Sources/MoonlightSlotA  moonlight-common-c, compiled with SlotA_ prefixes
  Sources/MoonlightSlotB  moonlight-common-c, compiled with SlotB_ prefixes
  Sources/MbedCrypto      mbedTLS 3.6, the protocol's crypto backend
  Sources/OpusCodec       Opus audio decoding
  Vendor/                 git submodules: moonlight-common-c, mbedTLS, Opus

Two streams in one process: moonlight-common-c holds all connection state in globals and its callbacks carry no context, so Selenite builds it twice through generated wrapper files with prefixed symbols and reaches each copy through a function table. Scripts/check-slot-symbols.sh proves the two copies share no unprefixed symbol; CI runs it. Solo streams use slot A, split screen uses both.

Development

swift test --package-path SeleniteKit

runs the test suite on the Mac. Frame pacing is tuned against real traces: record them on a device, then replay every mode against the same input:

PACER_TRACE=<dir> PACER_MODES=lowLatency,smooth,smoothPlus \
  swift test --package-path SeleniteKit --filter pacerTraceReplay

The replay reports latency, judder per minute, stalls and drops per mode.

Credits and license

Selenite is licensed under the GPL-3.0. It builds on:

• moonlight-common-c (GPL-3.0), the GameStream protocol core
• Mbed TLS (Apache-2.0)
• Opus (BSD-3-Clause)

Selenite is not affiliated with LizardByte, the Sunshine project or the Moonlight project.