enricobuehler
63bc2bb10f
The punktfunk-web unit serves HTTP/1.1 over TLS with the host's own self-signed identity cert, but several guides still told users to open http://<host>:47992, which fails. Correct the scheme everywhere and note the one-time browser cert warning in the canonical + SteamOS docs. The RPM %post web hint was doubly wrong (http://<host-ip>:3000): wrong scheme and wrong port — the service listens on :47992, not the :3000 dev default. Also fixes scripts/web-init.sh, so the URL the SteamOS/Linux installer prints at the end of setup is correct too. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
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title, description
| title | description |
|---|---|
| Windows Host | Run the Punktfunk streaming host on a Windows PC — a first-class, all-vendor, virtual-display host. |
Set up a Punktfunk host on a Windows 11 PC (22H2 or newer) and stream its desktop or games to any Punktfunk or Moonlight client. A signed installer registers a Windows service that streams at the client's exact resolution and refresh via Punktfunk's own virtual display — including HDR10 (10-bit BT.2020 PQ) when your Windows desktop is in HDR mode. The virtual display is created on the fly, so you need no second monitor and no dummy HDMI plug, and capture keeps working even on the secure desktop (UAC prompts, the lock screen).
New to this? Skim Requirements first.
Read Security & Safe Use before you set this up. The Windows host runs as a
LocalSystemservice (so it can capture the secure desktop and stream headless), which makes it a high-privilege component — keep it on a trusted network, never expose it to the internet, and prefer a dedicated or gaming PC over a machine that holds your most sensitive data.
This page is about the Windows host — streaming from a Windows PC. To stream to a Windows PC, see the Windows client.
Requirements
-
Windows 11 22H2 (build 22621) or newer, x64. Windows 10 — including LTSC — and Windows 11 21H2 are not supported: the virtual-display driver needs the IddCx 1.10 driver framework, which first shipped in Windows 11 22H2. On older Windows the driver installs but can't start ("punktfunk Virtual Display" shows Code 10 in Device Manager and streaming fails); the installer therefore refuses to run there. ARM64 is not built either (no ARM64 NVIDIA driver, and the virtual-display driver is x64-only).
-
A GPU for hardware encode — the host auto-detects the vendor:
- NVIDIA → NVENC
- AMD → AMF
- Intel → QSV
No discrete GPU? The host falls back to a software H.264 encoder (higher CPU use, lower quality — fine for light desktop use).
-
No gamepad prerequisite. The virtual gamepad drivers are bundled in the installer — there is nothing else to download. (Earlier builds needed ViGEmBus; it is no longer used.)
Install
Download the signed punktfunk-host-setup-<ver>.exe from the
latest release and run it. The installer:
- drops the host into
C:\Program Files\punktfunkand registers + starts thePunktfunkHostservice, - installs the bundled virtual-display driver (
pf-vdisplay) so the host can create per-client displays, - installs the bundled virtual gamepad drivers (DualSense, DualShock 4, Xbox 360),
- registers the bundled HDR Vulkan layer so Vulkan games can enable HDR over the virtual display,
- sets up the web management console (see below).
For an unattended install, append /VERYSILENT. Upgrades and uninstall go through Add/Remove
Programs; your config and pairings are kept across upgrades. Prefer the CLI, or want the full
service/firewall details? See Running as a Service → Windows.
Packaging internals live in
packaging/windows.
Web console & pairing
See The Web Console for the console + pairing model shared with the Linux host; the Windows specifics follow.
The installer also sets up the web management console (status, paired devices, the PIN pairing
flow): it bundles the console plus its own runtime and runs it as the PunktfunkWeb task on
https://<this-PC>:47992, starting at boot.
Console login password
You choose the console login password during setup — a secure random default is pre-filled and
shown on the installer's final page. It's stored in %ProgramData%\punktfunk\web-password, readable
only by Administrators and SYSTEM. To read or change it (with the schtasks restart), see
The Web Console → Login password; forgot it entirely?
Forgot your Password?.
The host requires PIN pairing by default (secure on a LAN). To connect the first time, open the console from any browser on the LAN, log in, go to Devices → arm pairing, and enter the PIN on your client. The host's own management API keeps every admin action loopback-only; off-loopback it serves only read-only status and game-library browsing to paired clients.
Configure
The service reads %ProgramData%\punktfunk\host.env. The defaults work out of the box; common knobs:
PUNKTFUNK_ENCODER=auto—autopicks NVENC/AMF/QSV by GPU vendor. Force one withnvenc,amf,qsv, orsw(software).PUNKTFUNK_HOST_CMD— the service runsserve --gamestreamby default (native punktfunk/1 plus the GameStream/Moonlight-compat planes). Set it toservefor a secure native-only host with no GameStream surface (GameStream pairs over plain HTTP and uses weaker legacy encryption — trusted LAN only).
Edit the file, then restart: punktfunk-host service stop / punktfunk-host service start. See the
Configuration reference for every option.
How it works
The host installs a LocalSystem SCM service that runs from Session 0 and launches a worker into
the interactive session (CreateProcessAsUserW). That lets it capture the secure desktop (UAC
prompts, the lock screen) and keep streaming across reboots with nobody logged in — the same model
Sunshine and Apollo use. Service registration, firewall rules, and the supervisor all live in
punktfunk-host service install; the installer just lays the exe down and calls it elevated.
Running as SYSTEM is what makes headless, log-in-optional streaming work — and it's why the host is a high-privilege component worth being deliberate about. punktfunk mitigates this with zero kernel drivers (the virtual display and gamepads are user-mode UMDF drivers), sealed internal channels between the host and its drivers, and Administrators/SYSTEM-only permissions on its secrets. See Security & Safe Use for the full picture, including why we recommend not hosting on your most sensitive machine.
One core, Windows backends
Most of Punktfunk is platform-agnostic. punktfunk-core (protocol, FEC, crypto, session, transport,
the C ABI), the QUIC control plane, the GameStream wire logic, the management API, and the per-frame
pipeline orchestration are all shared with the Linux host. The Windows host is a set of
#[cfg(windows)] backends behind the same traits the Linux host uses:
| Subsystem | Linux backend | Windows backend |
|---|---|---|
| Capture | xdg ScreenCast portal → PipeWire (dmabuf) | IDD direct-push — the pf-vdisplay driver copies finished frames into a host-owned shared GPU texture ring that the host consumes in-process (no Desktop Duplication, no Windows.Graphics.Capture); FP16/10-bit when the desktop is HDR |
| Virtual display | KWin / Mutter / Sway / gamescope | pf-vdisplay signed IDD — create a WxH@Hz monitor per session, capture it, tear it down |
| Encode | NVENC (CUDA) / VAAPI (AMD·Intel) / software | NVENC (NVIDIA) · AMF (AMD) · QSV (Intel) · software H.264; HEVC Main10 / BT.2020 PQ for HDR |
| Input — mouse/keyboard | libei / wlr protocols | SendInput (Win32 VK + absolute mouse) |
| Input — gamepads | uinput Xbox 360 + UHID DualSense/DS4 | UMDF virtual pads — DualSense, DualShock 4, Xbox 360 (XUSB) + rumble |
| Audio capture | PipeWire sink-monitor | WASAPI loopback |
| Virtual mic | PipeWire Audio/Source |
WASAPI virtual mic |
The virtual display is pf-vdisplay, Punktfunk's own all-Rust Indirect Display Driver (IDD). The
host creates a shared GPU texture ring and the driver pushes finished frames straight into it — a real
virtual display at the client's exact WxH@Hz, with no physical monitor and no dummy plug, captured
in-process from Session 0 so the secure desktop streams too. There is no Desktop Duplication or
Windows.Graphics.Capture path: IDD direct-push is the only capture path. The signed driver is bundled
and staged by the installer and is required — without it the host can't create a session (there is
no monitor-capture fallback).
HDR
When your Windows desktop is in HDR mode, the host captures it as 10-bit, encodes HEVC Main10 / BT.2020 PQ, and the client auto-detects HDR from the stream. A small always-on Vulkan layer (bundled and registered by the installer) also lets Vulkan games enable HDR over the virtual display — something the NVIDIA/AMD drivers otherwise refuse on an indirect display. The layer is self-gating: it's a no-op on SDR and on real monitors. HDR is Windows-only (the Linux host is 8-bit, blocked upstream).
Notes & limits
- AMD / Intel encode is newer. The NVENC path is the most exercised; AMF (AMD) and QSV (Intel) are built and tested in CI but less battle-tested on real hardware. Software H.264 is the GPU-less fallback.
- x64-only. No ARM64 build — no ARM64 NVIDIA driver, and the virtual-display driver is x64-only.
- Newer than the Linux host. The Linux host is the most battle-tested path; the Windows host is more recent, with the virtual-mic and AMD/Intel encode backends the youngest pieces.
Trouble? See Troubleshooting and Pairing.