The host cursor stops riding the video and becomes a real OS cursor on the client (the Parsec/RDP model): pointer feel no longer pays the capture→encode→network→decode→present round trip. Wire (M2a): - Hello grows a client_caps trailing byte (CLIENT_CAP_CURSOR) after the fixed display_hdr block — presence disambiguated by remaining length, which caps the post-HDR tail at 27 bytes (documented); Welcome answers HOST_CAP_CURSOR (capable-and-asked, the 444/clipboard precedent). - CursorShape (0x50, control stream): serial + dims + hotspot + straight RGBA, ≤120px/side so the u16 frame always fits (128² would overshoot); client caches by serial — re-showing a known shape costs 14 bytes, not a bitmap (RDP pointer-cache for free). - CursorState (0xD0 datagram): serial + visible/relative_hint flags + position, sent once per encode-loop tick — latest-wins, self-healing under loss, no refresh timer. relative_hint is reserved for M3. - Client core: two new planes (control-task + datagram-task arms) → next_cursor_shape/next_cursor_state; connect() grows client_caps (C ABI passes 0 until the v11 cursor poll fns exist). Host (M2b, Linux portal only): - handshake::cursor_forward is THE predicate (client asked ∧ Linux ∧ compositor ≠ gamescope) — Welcome bit and session wiring both read it. - SessionPlan.cursor_blend goes false for a forwarding session; the encode loop ticks a CursorForwarder every iteration: shape-serial diff → control-task bridge (mirrors probe_result), state datagram → conn. - CursorOverlay/capture CursorState carry the hotspot through (nearest-neighbor downscale backstop for XL cursors, unit-tested). Presenter: - CursorChannel drains both planes per loop iteration; shapes become SDL color cursors (from_surface + hotspot), applied while the desktop mouse model is engaged; visibility follows the host; capture/released hands back the system cursor. Sessions advertise the cap when they START in desktop mode. Verified on .21: fmt + clippy -D warnings (7 crates) + tests green (core 218 incl. new wire roundtrips, host 245 incl. e2e + forwarder downscale tests). Co-Authored-By: Claude Fable 5 <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