Files
punktfunk/crates/punktfunk-host
enricobuehlerandClaude Opus 5 54a37aeb46 docs(pf-capture): truth pass over comments, docs and log strings (sweep Phase 1)
Every item here is prose that actively misdirects a maintainer or an operator. Landing it before
the defect fixes means those diffs get reviewed against accurate comments.

1.1 (X5) — split two merged doc blocks that documented the item ABOVE them: `hdr_meta`'s whole
contract was glued onto `fn cursor()` in lib.rs (leaving `hdr_meta` undocumented), and
`hdr_p010_selftest_at`'s was glued onto `hdr_p010_convert_bars_on_luid` in dxgi.rs. rustdoc for
the trait's central HDR contract was simply wrong.

1.2 (L9 doc half) — the `Capturer` trait doc advertised a "bounded drop-oldest channel". The
Linux portal's `sync_channel(8)` + `try_send` is drop-NEWEST: under a consumer stall the arriving
frame is discarded and the encoder gets the stalest queued one. Say so. (Phase 2.6 changes the
behaviour; this commit only stops the doc from lying about today's code.)

1.3 — delete the DONT_FIXATE claim from the dmabuf offer comment. `build_dmabuf_format` emits a
plain MANDATORY `ChoiceEnum::Enum` and `param_changed` re-emits nothing, so there is no two-step
DMA-BUF handshake here; libspa 0.9's `ChoiceFlags` cannot even express DONT_FIXATE. Recorded as a
real follow-up instead of an implemented thing.

1.4 — `mainloop.run()` no longer "blocks until process exit": the quit channel attached above it
stops the loop from `PortalCapturer::drop`.

1.5 (L11) — the 6-arm negotiation log ladder told a fully zero-copy PyroWave session "VAAPI
encode with the CPU capture path — zero-copy was disabled", one line after logging that it had
advertised the PyroWave device's dmabuf modifiers: the passthrough arm was gated on
`pyrowave_modifiers.is_empty()`, so the pyrowave case fell through to the CPU warning. Ungate it;
the CPU-path arm is now reachable only when no dmabuf is advertised at all, which is what it
claims. Its parenthetical also gains the third real cause (the session asked for CPU frames).
Control-flow-neutral for every other combination.

1.6 (W13) — `kick_dwm_compose` claimed a "sub-millisecond" round trip while its
cursor-on-a-sibling-display branch sleeps 35 ms on the CALLER's thread. State the cost on the
function and at both call sites, including which one is on the live frame path.

1.7 (W16) — DDA-era residue, DDA having been removed:
  - retarget the win32u hook's rationale + all four log strings: its job is no longer "keep DDA on
    one adapter" but "keep the virtual display on the adapter SET_RENDER_ADAPTER pinned" (a DXGI
    reparent surfaces as the driver's TEX_FAIL render-adapter mismatch). The hook stays installed.
  - the per-monitor-v2 DPI awareness rationale likewise: not DuplicateOutput1's E_ACCESSDENIED any
    more, but keeping cursor/window coordinates in the PHYSICAL pixels the host's CCD geometry
    (`source_desktop_rect`, `desktop_bounds`) is already in.
  - `HYBRID_HOOK_HITS` was write-only. Surface it as `hybrid_hook_hits()` on the IDD-push open
    line, which is the first point where DXGI has actually been exercised — the patch-readback
    check proves the bytes landed, only this proves DXGI reaches the export.
  - delete `hdr_p010_selftest()`: an unreachable 64×64 wrapper (main.rs calls
    `hdr_p010_selftest_at`); its description moves onto the function that survives.
  - `VideoConverter`'s docs promised a P010/BT.2020 output and a live scRGB input path. It pins
    `YCBCR_STUDIO_G22_LEFT_P709` unconditionally and its only caller always passes
    `scrgb_input: false`.

1.8 (X7) — the native handshake's 4:4:4 gate comment stated the OPPOSITE of what
`pf_capture::capturer_supports_444` returns on Windows ("delivers subsampled NV12/P010 today, so
it returns false there" — it forwards `resolved_backend_ingests_rgb_444()` and the IDD ring passes
BGRA through for an SDR 4:4:4 session).

No `.rs` behaviour delta: comments, doc comments and log strings, plus 1.5's control-flow-neutral
ladder and 1.7's counter accessor. Linux tests 6/6; clippy --all-targets clean on both targets.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-07-26 10:27:06 +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