enricobuehlerandClaude Fable 5
fc335b39e9
EncoderCaps::blends_cursor's contract said the HOST must fall back to capturer-side compositing when a cursor-as-metadata session lands on an encoder that can't composite — but that host half was never built: open_video warned and the session streamed WITHOUT a pointer (confirmed on the VAAPI dmabuf and libav-NVENC CUDA paths; latent on vulkan RGB-direct/native-NV12). The negotiation is now caps-aware, ahead of capture, on both planes: * pf-encode grows cursor_blend_capable() — the pre-open dispatch mirror (sibling of linux_native_nv12_ok) answering whether the resolved backend composites frame.cursor; its pure core is test-pinned arm by arm. * Native plane: handshake::cursor_forward grants the cursor channel only where the resolved backend can blend (the capture-mouse flip makes the host draw the pointer on demand); denied sessions keep the pre-channel path — the compositor EMBEDS the pointer, never cursorless, never doubled. The Welcome's HOST_CAP_CURSOR bit is computed once and read back at both session-wiring sites instead of recomputed. SessionPlan::output_format additionally keeps every cursor-blend session off producer-native NV12 (the arm with no CSC to fold a cursor into), and vulkan RGB-direct now yields to a cursor-blend session even when pinned (EFC cannot composite; the open logs the override). Windows plans cursor_blend=false via the new shared cursor_blend_for() rule — the IDD capturer composites the pointer itself, and asking the encoder anyway fired the blends-cursor warn spuriously on every cursor-channel session. * GameStream plane: the hardcoded cursor_blend=true is gone. The portal source asks for cursor-as-metadata only when the resolved backend blends, otherwise negotiates an Embedded pointer (choose_cursor_mode's new ladder); the capturer pool now also keys on that mode. The virtual-output source passes false — its capture embeds the pointer where it can. The per-arm warns in vulkan_video (RGB-direct, native-NV12) are now structurally unreachable and removed. open_video's post-open check stays as the single backstop for what planning cannot see: a Vulkan-open falling back to VAAPI mid-session, and the gamescope residual (no embedded mode exists there, so a never-blending backend — H.264-on-AMD VAAPI, software — still streams cursorless; fixing that needs a compositing stage, deliberately not built in this pass). Zero-copy is preserved throughout — every fallback is a capture-negotiation change, never a readback. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
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 atapi/openapi.json) drives status, paired devices, and on-demand pairing; the browser UI is inweb/.
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
Related
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