Files
punktfunk/crates/punktfunk-host
enricobuehlerandClaude Opus 4.8 0af280a793 feat(windows/capture): host-side cursor compositing for the capture model — the deterministic fix
Root cause, proven on-glass across five driver builds: a declared IddCx
hardware cursor is IRREVOCABLE. There is no un-declare DDI, the
empty-caps re-setup is rejected INVALID_PARAMETER, and after a
successful same-mode re-commit with the driver's re-declare provably
suppressed (sticky per-target flag, zero re-setups logged) DWM still
never composites the software cursor back into the monitor's frames.
Every DWM-based composite flip is therefore unfixable.

The composite (capture) model is now implemented in OUR pipeline:
- the driver keeps its hardware cursor declared for the session's whole
  life (the state that works) — frames stay pointer-free always;
- in composite mode try_consume routes the conversion through a blend
  scratch: slot copy + one alpha-blended quad of the GDI poller's shape
  at its polled position (CursorBlendPass — fullscreen-triangle VS with
  viewport placement, straight-alpha PS, sRGB→linear for FP16/HDR
  rings), covering all four convert paths (NV12, 4:4:4 copy, P010,
  PyroWave) GPU-side under the slot's keyed mutex;
- pointer-only motion produces no driver publish (declared hw cursor),
  so try_consume REGENERATES from the last slot whenever the polled
  cursor state changes — the cursor moves on a static desktop at tick
  rate, without faking freshness for the stall/death watchdogs;
- set_cursor_forward becomes purely host-internal state; the
  SET_CURSOR_FORWARD IOCTL machinery is no longer used by the host
  (driver keeps it, dormant) and its sender plumbing is removed.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
2026-07-22 23:43:23 +02:00
..

punktfunk-host

The streaming host — the program you run on the machine whose desktop or games you want to stream. For each client that connects, it spins up a virtual display sized to that device, captures it on the GPU, encodes with hardware NVENC/VAAPI/AMF/QSV, and sends it out over a low-latency transport — no physical monitor, no letterboxing, no rearranging your real screens.

It speaks two protocols from one process:

  • GameStream — so any Moonlight / Artemis client works day one.
  • punktfunk/1 — punktfunk's own faster protocol (QUIC control plane, GF(2¹⁶) FEC + AES-GCM data plane) that the native clients use.

Runs on Linux (the primary, most battle-tested path) and Windows (x64). The shared protocol, FEC, and crypto live in punktfunk-core; this crate is everything platform-facing around it.

What it does

  • Per-client virtual displays at the exact WxH@Hz. Linux uses per-compositor backends — KWin, gamescope, Mutter, and Sway/wlroots; Windows uses its own all-Rust IddCx virtual display, even on the secure desktop (UAC / lock screen).
  • GPU zero-copy capture → encode. dmabuf → CUDA/Vulkan → NVENC on Linux; on Windows the host pushes frames straight into its own IDD (sealed IDD-push, no screen-scraping) → GPU encode. Encoders auto-select by GPU vendor: NVENC (NVIDIA), VAAPI (Linux AMD/Intel), AMF/QSV (Windows AMD/Intel), or software H.264 as a floor. HDR/10-bit and HEVC 4:4:4 supported.
  • Input injection. Mouse/keyboard (libei / gamescope EIS / wlr / Windows SendInput) and virtual gamepads — Xbox 360/One, DualSense, DualShock 4 — with rumble and HID feedback back-channels.
  • Audio both ways. Opus audio host→client, plus a virtual microphone the client can talk into.
  • Trust & discovery. A persistent host identity, SPAKE2 PIN pairing (default) or TOFU, and mDNS auto-advertisement so clients find the host without typing an IP.
  • Management API + web console. A REST API (mgmt.rs, OpenAPI at api/openapi.json) drives status, paired devices, and on-demand pairing; the browser UI is in web/.

Run it

punktfunk-host serve runs inside your desktop session. Bare serve is the secure native-only default (punktfunk/1 + the management API); add --gamestream on a trusted LAN to also accept stock Moonlight clients.

# Linux, from the repo root (see the repo README "Running on this box" for the headless recipe):
cargo run -rp punktfunk-host -- serve                 # native-only (secure default)
cargo run -rp punktfunk-host -- serve --gamestream    # + Moonlight compatibility

Then pair from the web console (https://<host-ip>:47992) or the client app.

Most people should install a package rather than run from source — see packaging/ (apt · rpm/COPR/bootc · Arch/sysext · Windows installer) and the per-platform guides at docs.punktfunk.unom.io/docs/install.

Subcommands

Command Purpose
serve The host (native punktfunk/1 + mgmt API; --gamestream adds Moonlight).
punktfunk1-host Standalone native-protocol listener for testing/measurement (--source virtual, --max-sessions).
openapi Print the management-API OpenAPI spec (regenerates api/openapi.json).
library Inspect the multi-store game library.
service · driver · web Windows: SCM service, driver install, bundled web console.
*-test / *-selftest / *-probe Diagnostics (input, zero-copy, HDR, compositor, gamepads).

--help lists them all.

Layout

src/
  main.rs            CLI + subcommand dispatch
  config.rs · session_plan.rs · session_tuning.rs · pipeline.rs   session setup + the frame pipeline
  vdisplay/          per-compositor virtual outputs (kwin · gamescope · mutter · wlroots)
  capture/ · capture.rs    screen/dmabuf capture (+ Windows IDD-push)
  encode/ · encode.rs      per-GPU encoders (nvenc · vaapi · ffmpeg_win (AMF/QSV) · sw)
  linux/zerocopy/    dmabuf → CUDA → NVENC bridges (EGL/GL tiled, Vulkan LINEAR)
  inject/ · inject.rs      input backends (libei · wlr · uinput gamepads · UHID DualSense/DS4)
  audio/ · audio.rs        Opus out + virtual mic (PipeWire / WASAPI)
  gamestream/        Moonlight compat: nvhttp · pairing · rtsp · control · stream · gamepad · apps
  native.rs      the native punktfunk/1 host (QUIC control + native-thread UDP data plane)
  mgmt.rs · native_pairing.rs · stats_recorder.rs   management API, pairing, perf capture
  hdr.rs · library.rs      HDR metadata; multi-store game library
  linux/ · windows/  platform-confined backends
  • punktfunk-core — the shared protocol · FEC · crypto core
  • Clients — the apps that connect (Apple · Linux · Windows · Android · probe)
  • Packaging & docs — install & operate
  • punktfunk-planning (internal planning repo) — architecture rationale and deep-dive plans