Files
punktfunk/crates/punktfunk-host
enricobuehler 449a67ce8d feat(protocol): per-AU host-timing plane (0xCF) — split host+network latency (stats phase 2)
The unified-stats equation's host+network stage was one opaque number
because the wire carried nothing but pts_ns. Now the host reports its own
share per frame: when the client's Hello sets VIDEO_CAP_HOST_TIMING (0x08),
the send thread emits a 13-byte 0xCF datagram — [tag][pts_ns u64][host_us
u32] — right after the AU's last packet leaves the socket, so host_us =
capture→fully-sent (capture read/convert, encode, FEC+seal, paced send)
against the same anchor the wire pts carries. Clients correlate by pts_ns
and derive network = (received + clock_offset − pts) − host_us; the two
terms tile per frame by construction.

Back-compat is free in all four combinations: old clients ignore unknown
datagram tags, old hosts ignore unknown cap bits (client keeps the combined
stage). The hardened data-plane format is untouched — this rides the
established QUIC side-plane pattern (0xC8…0xCE). NativeClient ORs the bit
in unconditionally and exposes next_host_timing(); the C ABI gains
PunktfunkHostTiming + punktfunk_connection_next_host_timing (additive).
The synthetic host emits 0xCF too, so pure-loopback protocol tests cover
the plane.

The probe reports the split (host_p50/p95_us · net_p50/p95_us) and is our
direct analogue of Sunshine's "host processing latency" — ours additionally
includes the paced send.

Validated on loopback (synthetic host + probe, debug build): 240/240 AUs
matched, host_p50 6.5 ms + net_p50 6.4 ms ≈ capture→received p50 13.0 ms.
Core suite + new 0xCF roundtrip/truncation test green; host+core+probe
clippy clean.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
2026-07-03 21:22:12 +00:00
..

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; DXGI/WGC → GPU encode on Windows. 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 DXGI/WGC)
  encode/ · encode.rs      per-GPU encoders (nvenc · vaapi · ffmpeg_win (AMF/QSV) · sw)
  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
  punktfunk1.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
  • design/ — architecture rationale and deep-dive plans