The 0xD1 pad-audio plane streams a DualSense's voice-coil haptics (back channel pair, 5 ms Opus frames) and speaker (front pair, 10 ms) per pad from a Windows host to the SDL clients, which render them into a USB DualSense's own 4-channel audio device. Wire (punktfunk-core, ABI v15): PAD_AUDIO_MAGIC 0xD1 [pad][kind][seq][pts] [opus]; CLIENT_CAP_PAD_AUDIO 0x04 / HOST_CAP_PAD_AUDIO 0x20; per-pad render capability rides GamepadArrival flags bits 8/9, sent only toward a host that advertised its cap so old hosts see byte-identical arrivals; silence is a frozen seq (mic-mute discipline), loss is a seq gap concealed via AudioGapTracker. HidOutput::AudioCtl (0xCD kind 0x06) forwards the 0x02 report's audio-control bytes 5..=10 change-only, value-deduped, with a once-per-pad "title asserted haptics-select" diagnosis log. Windows host endpoint provider (audio/windows/pad_endpoint.rs): per-pad render endpoints are additional devnode instances of Valve's Steam Streaming Speakers driver (SetupDiRegisterDeviceInfo, NOT the class installer - it needs an interactive window station), stamped with DualSense identity: desc "Wireless Controller", device name "DualSense Wireless Controller", ContainerId = the virtual pad's PFDS GUID, 4ch/48k format triplet. IPropertyStore route first, ACL-repaired registry fallback (the MMDevices keys deny writes even to SYSTEM; the owner's implicit WRITE_DAC + an ACE for S-1-5-18 resolved by SID is the way in). Provisioned at host startup (PUNKTFUNK_PAD_AUDIO, PUNKTFUNK_PAD_AUDIO_SLOTS, default 1), idempotent via a persisted PunktfunkPadIndex marker; pad endpoints are structurally ineligible for the mic/loopback wiring plan and guarded against default- device theft; capture is WASAPI loopback on the stamped endpoint. Devtest: punktfunk-host pad-endpoint ensure|remove|status. Host service (native/pad_audio.rs): per-(session,pad) thread, loopback 4ch -> pair splitter -> per-kind stereo Opus (48k LowDelay CBR 64k) -> per-kind silence gate (opens at peak>=1e-3, 250 ms hangover, gated = no send + frozen seq) -> datagrams. Spawned from the native input pump when a DualSense/Edge arrival carries audio bits and both caps negotiated; idempotent re-arrivals; reaped on remove and teardown. Client tier A (pf-client-core/pad_audio.rs): settings pad_haptics (default on) and pad_speaker (default "pad"); tier A = wired USB DS5/Edge via SDL connection state with an audio-sibling fallback; correlation maps the SDL HID path to the pad's own render endpoint (Windows: ContainerId match + 4ch gate via registry; Linux: Sony sink signature); renderer decodes both kinds into a quad interleave and plays it on the pad's endpoint (WASAPI autoconvert / PipeWire target.object, 240-2400 frame ring floor, dont-reconnect so an unplug never re-routes haptics to the desktop speakers). SDL's DualSense driver sets "disable audio haptics" whenever it drives rumble emulation, so tier-A pads suppress wire rumble and send one cleared-enable-bits effects packet to keep the actuators live; AudioCtl bytes fold back into the effects packet at report-minus-one offsets. Verification: punktfunk-core 265 tests (macOS) + clippy -D warnings (mac + Linux docker); pf-inject 85 tests (Linux docker); punktfunk-host cargo check + clippy + 19 pad tests + 46 audio-module tests (Windows box); pf-client-core 30 tests + clippy (Linux docker CI image) + cargo check (Windows box); punktfunk-client-session clippy (Linux) + check (Windows); cargo fmt --all --check clean on the final tree. NOT yet verified: any on-glass run (host deploy + real title + physical pad), the stamp-route split at runtime, exclusive-mode Initialize isolation, Linux-host emission (the per-pad PipeWire sink is not in this change - Windows hosts only). Scope excluded deliberately: tier B (Apple CoreHaptics) and tier C (haptics->rumble derivation), pad_speaker="mix", Android leg, settings UI surfaces (keys are serde-defaulted), GameStream-plane arrivals (audio_caps always 0 there). 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