punktfunk/docs-site/content/docs/status.md

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Status & Progress	Where the work stands across the core, the host, and the native clients.

A high-level view of where punktfunk stands. The ordered plan of work is on the Roadmap.

Milestones at a glance

Milestone	State
Core — punktfunk-core + C ABI (protocol · FEC · crypto)	✅ complete & hardened
GameStream host (Moonlight-compatible)	✅ working end-to-end; HDR/surround-audio polish open
Native protocol — punktfunk/1 (QUIC control + UDP data, GF(2¹⁶) Leopard FEC + AES-GCM)	✅ full session planes, validated live
Windows host (x64)	🟡 implemented & shipping as a signed installer; NVIDIA/AMD/Intel encode, newer than the Linux host
macOS / iOS / iPadOS / tvOS client	✅ full client; on-glass-validated stage-2 presenter is the default
Linux client (punktfunk-client, relm4/GTK4 shell + Vulkan session)	✅ full client; Vulkan Video → VAAPI → software decode
Windows client (punktfunk-client, WinUI 3)	✅ ships as signed MSIX; hardware decode validated on NVIDIA + Intel; HDR on-glass validation pending
Android client (phone + Android TV)	✅ full client; hardware HEVC decode + HDR10
Web console (over the management API)	✅ status · devices · pairing

What works today

punktfunk is a low-latency desktop and game streaming host with first-class Linux and Windows support — and native clients on macOS, iOS/iPadOS/tvOS, Linux, Windows, and Android. (The Windows host is newer than the Linux host.)

• Two protocols. The host speaks the GameStream protocol, so any Moonlight client works out of the box, plus its own lower-latency punktfunk/1 protocol (QUIC control plane + UDP data plane with GF(2¹⁶) Leopard FEC and AES-GCM).
• Native resolution, no scaling. Every session gets a virtual display at the client's exact resolution and refresh rate, via per-compositor backends for KWin, gamescope, Mutter, and Sway/wlroots.
• Zero-copy GPU pipeline. Captured frames stay on the GPU — dmabuf → CUDA → NVENC on NVIDIA, and VAAPI or Vulkan Video on AMD/Intel — with automatic split-encode at very high resolutions. Stable 240 fps at 5120×1440 has been measured. A GPU-less software H.264 encoder exists as an explicit fallback.
• HDR (10-bit). An HDR Windows desktop is captured and encoded as HEVC Main10 (BT.2020 PQ) to HDR-capable clients (Windows, Android). On Linux there are two routes. A GNOME 50+ host can mirror an HDR monitor over the GameStream desktop-capture source (PUNKTFUNK_VIDEO_SOURCE=portal): the portal negotiates the 10-bit PQ screencast formats GNOME 50 added and encodes Main10 PQ. And a gamescope host can stream HDR off its virtual output with the punktfunk-gamescope build (on by default when installed) — games get real HDR surfaces and the composite is captured as 10-bit BT.2020 PQ. (Run punktfunk-host hdr-probe to check either; both are pending on-glass validation.) The other Linux virtual displays — Mutter, KWin, wlroots — still stream 8-bit: their virtual-monitor screencasts are SDR-only upstream.
• Secure by default. A SPAKE2 PIN pairing ceremony establishes trust (the host shows a 4-digit PIN; an attacker gets a single online guess, no offline dictionary attack). Trust-on-first-use (TOFU) remains an explicit opt-in for fully trusted LANs.
• LAN auto-discovery. Hosts advertise over mDNS (_punktfunk._udp); clients browse and list them automatically.
• Full input. Mouse, keyboard, and gamepads (including DualSense touchpad, motion, rumble, lightbar, player LEDs, and adaptive triggers) in both directions.
• Audio both ways. Opus desktop audio host → client, plus an opt-in, paired-only client microphone uplink.
• Management surface. A REST management API with a checked-in OpenAPI document, plus a web console for status, paired devices, and pairing.

Native clients

Client	Highlights
macOS / iOS / iPadOS / tvOS	VideoToolbox HEVC + AV1 decode (AV1 on hardware that decodes it — M3-class Macs, A17 Pro-class iPhones), GameController capture, full DualSense feedback, mDNS discovery, PIN pairing + TOFU, network speed test, latency HUD. Stage-2 presenter (VTDecompressionSession → CAMetalLayer, ~11 ms p50 capture→present) is validated on glass and is the default (stage 1 remains the fallback when Metal is unavailable). Ships as one universal TestFlight build / App Store listing.
Linux (punktfunk-client)	relm4/GTK4 shell; streams run in the spawned Vulkan session presenter. Hardware decode via Vulkan Video (all vendors, incl. NVIDIA) with VAAPI dmabuf and software fallbacks, PipeWire audio + mic, SDL3 gamepads incl. DualSense, mDNS discovery, PIN pairing + TOFU, speed test, Skia console UI + tiered stats overlay. Ships as Flatpak, apt, rpm, and Arch packages.
Windows (punktfunk-client)	WinUI 3 shell; streams run in the Vulkan session presenter with a per-vendor decode chain — Vulkan Video → D3D11VA → software on NVIDIA/AMD, D3D11VA → Vulkan Video → software on Intel and others — plus HDR10, WASAPI audio + mic, SDL3 gamepads incl. DualSense, mDNS discovery, and the full PIN/TOFU trust surface. Ships as a signed MSIX (x86_64 + ARM64). Hardware decode and HDR10 present validated on glass on NVIDIA and Intel (incl. HDR pass-through on the Intel D3D11VA path).
Android (phone + Android TV)	Kotlin app with a Rust core over JNI. NDK AMediaCodec hardware HEVC decode + HDR10 (Main10/BT.2020 PQ), Opus/Oboe audio + mic, gamepad input with rumble/HID feedback, mDNS discovery, PIN pairing + TOFU (Keystore identity), tiered stats overlay (three-finger tap), custom resolutions, and D-pad/controller focus navigation for TV. Ships to the Google Play Internal Testing track.

punktfunk-probe is a headless reference and measurement client (for testing and benchmarking, not everyday use).

Validated live on

The stack has been validated live on a range of hosts and clients:

• Hosts: Ubuntu (GNOME / KDE), Fedora KDE, and Bazzite (gamescope) on machines with RTX-class NVIDIA GPUs, across the KWin, gamescope, Mutter, and Sway/wlroots backends.
• Clients: native macOS, Linux, Windows, and Android clients against live hosts, plus stock Moonlight clients over the GameStream path.
• Cross-machine latency is measured and skew-corrected (a wall-clock handshake removes the inter-machine clock offset), so capture-to-present numbers are valid across the LAN.

Highlights

Notable capabilities that have landed, newest first:

• Tiered stats overlay everywhere. One shared stats vocabulary with Compact / Normal / Detailed levels on every client, cycled live in-stream — see Understanding the Stats Overlay.
• Per-client display scaling on GNOME. The host persists each client's scale itself and reapplies it on reconnect (GNOME's virtual-monitor API exposes no stable identity to key it on).
• Adaptive bitrate. With bitrate set to Automatic, the host re-targets the encoder mid-stream as the link's measured capacity changes.
• Gamepad console shell. The session client carries a full controller-driven shell — host list, PIN pairing, settings, screen transitions, and an on-screen keyboard — usable with no desktop at all (e.g. gamescope on a Steam Deck).
• Native Linux client (stage 1). GTK4/libadwaita app that links punktfunk-core directly: mDNS host list, TOFU + SPAKE2 PIN pairing, FFmpeg HEVC decode, PipeWire audio with mic uplink, SDL3 gamepad capture with rumble/lightbar feedback, layout-independent keyboard, absolute mouse, fullscreen, and a stats overlay. (Since re-architected: streams now run in a spawned Vulkan session presenter with Vulkan Video decode on all vendors.)
• Delegated pairing approval. An unpaired device that knocks on a pairing-required host appears as a pending request in the web console's Pairing page; one click approves and pins its certificate — no PIN fetched out of band.
• Concurrent sessions. The host serves multiple clients at once (bounded by an NVENC limit), each with its own virtual output and encoder — e.g. stream the same desktop to a laptop and a TV simultaneously.
• Cross-machine latency HUD + wall-clock skew handshake. A short NTP-style handshake aligns client and host clocks, making capture-to-received latency valid across machines; the Apple client surfaces a skew-corrected capture-to-receipt p50/p95 in its HUD.
• Native LAN auto-discovery. Hosts advertise _punktfunk._udp over mDNS (with TXT records carrying the protocol, cert fingerprint, and pairing requirement); clients discover and list them automatically.
• 1 Gbps data plane. Batched sendmmsg/recvmmsg, a microburst-capped paced send thread, and larger socket buffers, exploiting the GF(2¹⁶) Leopard FEC that breaks the classic ~1 Gbps GameStream ceiling.
• Boot appliance. A headless compositor session plus host systemd units, so a host can come up and stream with no interactive login.
• Network speed test + settable bitrate. Bitrate negotiation and an in-band bandwidth probe inform the client's bitrate picker instead of guesswork.
• Rich DualSense. A full UHID DualSense backend on the host (gamepad, motion, touchpad, lightbar, player LEDs, adaptive triggers) with feedback carried back to the clients.
• AV1 + surround audio are implemented and unit/live-capture tested.

In flight / next

See the Roadmap for the ordered list. Near-term:

• True glass-to-glass latency — combine the client present-stamp (decode → present) with the host render → capture term for a complete end-to-end number.
• On-glass validation of the Windows client's HDR present path (hardware decode and the GUI are already validated on NVIDIA and Intel).
• gamescope multi-user isolation — per-session input/audio so concurrent sessions can be fully independent desktops (the shared-desktop multi-view case already works).