WP4 / D2. Protocol activation of a full-trust packaged app delivers the URI as the command line, so a browser prompt, `start punktfunk://…` and a written `.lnk` all arrive the same way — as a positional argument, the same door the Linux shell uses. What Windows does not give us is single-instancing: unlike GApplication, a second activation is simply a second process. So the first instance claims the named mutex `unom.punktfunk.client` and any later one hands its URL to the winner over `WM_COPYDATA` and exits — one window, and the link opens where the user's hosts already are. The hand-off retries while the primary's window is still coming up (a shortcut double-clicked during startup is the ordinary case), and a hand-off that finds nobody falls through so this process becomes the shell that opens it. A link is never silently dropped, which is also why the inbox is a queue: two shortcuts in quick succession are two links. Routing is the same four lines of translation as on Linux, because the decisions belong to `plan_from_link`: a resolved link becomes the call a tile click makes, with the same wake, trust and error surfaces. Never preempting a live session is checked here, since only this layer knows one is running. The manifest declares the protocol and an app execution alias rather than writing registry keys, so uninstall leaves nothing behind — and Windows' own "allow this app to handle punktfunk links?" prompt is the origin friction the design wants, not duplicated in-app. (Manifest comments are free of double hyphens: XML forbids them and makepri rejects the whole file, which is how the console flag broke the v0.15.0 build. A test parses the substituted manifest and asserts both declarations, so that can't rot silently.) "Create shortcut…" writes a `.lnk` targeting the ALIAS with the URL as an argument, not a `.url` internet shortcut: both work while the scheme is registered, only this one still works if it isn't, and targeting the alias keeps it valid across updates when the package path changes. Verified on the CI VM (192.168.1.133): clippy -D warnings clean and its tests green. Not yet exercised on glass — `start punktfunk://…` cold and with the app running, and a written shortcut, still want a real desktop session. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
punktfunk — Windows client
The native Windows app for streaming a punktfunk host to your PC. A modern WinUI 3 app that discovers hosts on your network, pairs with a PIN, and streams at your display's own resolution and refresh rate — with a hardware-accelerated D3D11 video path and HDR.
It's pure Rust: the UI is WinUI 3 driven through windows-reactor
(a declarative, React-like framework), and it links the shared punktfunk-core directly to speak
the fast punktfunk/1 protocol.
Features
- Hardware decode, GPU present — FFmpeg HEVC with a D3D11VA zero-copy path (decoder and
presenter share one D3D11 device; NV12/P010 textures sampled straight into a
SwapChainPanelcomposition swapchain), with a robust software-decode fallback. - HDR10 — advertise 10-bit/HDR, detect PQ in-band, and flip the swapchain to
R10G10B10A2+ ST.2084 with HDR10 metadata. - Your display's native mode — the host builds a virtual display at exactly your WxH@Hz.
- Audio both ways — WASAPI render + mic capture.
- Full controller support — SDL3 gamepads with rumble, lightbar, and DualSense feedback.
- Your display's native mode, really — "Native display" resolves the actual size + refresh of the monitor the window is on at connect time.
- Find hosts automatically — mDNS discovery lists hosts on your LAN, alongside saved and manual entries. First connect does a one-time SPAKE2 PIN pairing (or TOFU on trusted LANs), then reconnects on a pinned identity. Saved hosts carry per-host actions: a network speed test (probe burst over the real data plane → recommended bitrate, applied in one tap) and forget.
- Polished shell — host cards, settings (resolution / refresh / host compositor / decoder / codec / bitrate / HDR / forwarded controller / gamepad type / system shortcuts / audio channels / mic / stats-overlay level), the tiered stats overlay (Off / Compact / Normal / Detailed — Ctrl+Alt+Shift+S cycles it live in the session window), and the full trust surface. Stream input uses Win32 low-level hooks with Moonlight-style capture: Ctrl+Alt+Shift+Q releases the pointer, a click on the stream re-captures it, and system shortcuts (Alt+Tab, Win, …) can act locally or forward to the host.
Builds and ships for both x64 and ARM64 as a signed MSIX.
Get it
Install the signed MSIX from the package registry — see docs.punktfunk.unom.io/docs/install-client. A stock Moonlight client also works over GameStream if you prefer.
Build from source
Windows-only (the crate builds as a stub on other platforms so the workspace stays green). You need
the MSVC toolchain, an FFMPEG_DIR FFmpeg tree, and CMake (SDL3 builds from source). windows-reactor's
build.rs downloads the Windows App SDK NuGets and needs CARGO_WORKSPACE_DIR set.
cargo build -p punktfunk-client-windows --target x86_64-pc-windows-msvc
# CLI paths for testing (no window):
punktfunk-client --discover # list hosts on the LAN
punktfunk-client --headless --connect host[:port] [--pin HEX] # connect, count frames, print stats
punktfunk-client --headless --speed-test --connect host[:port] # probe burst → recommended bitrate
CARGO_HOMEmust be an ASCII path — non-ASCII characters break SDL3's MSVC precompiled-header build. Packaging (MSIX manifest, signing) lives inpackaging/.
Layout
src/
main.rs entry point + CLI paths (--discover · --headless · --speed-test)
app/ WinUI 3 shell (windows-reactor), one module per screen:
mod (root/router) · hosts · connect · pair · speed · settings ·
licenses · stream · style (shared cards/pills/monograms)
present.rs · gpu.rs SwapChainPanel D3D11 composition swapchain; shared D3D11 device
video.rs FFmpeg HEVC decode (D3D11VA zero-copy + software fallback)
audio.rs WASAPI render + mic capture
gamepad.rs SDL3 controllers + rumble/lightbar/DualSense feedback
input.rs Win32 low-level hooks → host input (pointer lock · click-to-capture)
session.rs session lifecycle over the NativeClient connector (+ speed probe)
trust.rs · discovery.rs persistent identity, TOFU/PIN pairing, mDNS browse
packaging/ MSIX manifest, signing, pack script
Related
- Documentation — quick start, pairing, troubleshooting
- Project README — the host, the other clients, and how it all fits together