enricobuehler
0eedfb3c1f
Drop the "Linux-first" framing across the README and docs site in favor of first-class Linux AND Windows hosts, and surface the Windows IDD-push virtual-display path as a distinct differentiator (punktfunk's own indirect display driver the host pushes frames into — a real virtual display, no physical monitor or dummy plug, even on the secure desktop). Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
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title, description
| title | description |
|---|---|
| How It Works | The ideas behind punktfunk — per-client virtual displays, the two protocols, and trust. |
You don't need to know any of this to use punktfunk, but it helps to understand what's happening when you connect.
A virtual display, sized to your device
When a client connects, the host asks your desktop to create a new virtual display at exactly the client's resolution and refresh rate, captures that display, and streams it. The virtual display is real to your desktop — apps can be moved onto it, games open on it — but it isn't tied to any physical monitor. When the client disconnects, the virtual display goes away.
That's why a 1080p60 laptop and a 1440p120 desktop can stream from the same host at the same time, each at its own mode — they each get their own virtual display.
How the virtual display is created depends on your host:
| Host | How |
|---|---|
| GNOME (Mutter) | A virtual monitor via the screen-cast API |
| KDE Plasma (KWin) | A virtual output via KWin's screencast |
| Bazzite / Steam (gamescope) | A nested gamescope session launched at the client's mode |
| Sway (wlroots) | A headless output added to the running session |
| Windows | A virtual-display driver — including punktfunk's own indirect display driver the host pushes frames straight into — a real virtual display, no physical monitor, even on the secure desktop |
That last one is the distinctive part on Windows: rather than only capturing an existing screen, punktfunk has its own indirect display driver (IDD), and the host can push finished frames straight into the driver. You get the same on-the-fly virtual display the Linux compositors give you — at the client's exact mode, with no physical monitor or dummy HDMI dongle, and even on the secure desktop (UAC / lock screen). That tight, push-based integration is unusual among Windows streaming hosts.
From screen to GPU to wire
Captured frames never touch the CPU on their way to the encoder. They go straight from the compositor to the GPU's NVENC hardware encoder (HEVC/H.264/AV1) and out to the network — a zero-copy GPU path that keeps latency low even at high resolutions and frame rates.
Two protocols
punktfunk speaks two protocols over the same host:
- GameStream — the protocol Moonlight uses. Any Moonlight client connects with no special software. This is the most compatible way in.
- punktfunk/1 (native) — a purpose-built protocol with a QUIC control channel and a UDP data channel hardened with forward error correction and encryption. It's lower-latency and more resilient on imperfect networks, and it's what the native clients (Apple, Linux, Windows, Android) use.
Both run from a single host process, so you don't choose up front — Moonlight clients use GameStream, the native clients use punktfunk/1.
Pairing and trust
The first time a device connects, you pair it: the host shows a short PIN, you type it into the client, and the two remember each other. After that the device reconnects automatically on a pinned cryptographic identity — no PIN, no account, no cloud. See Pairing & Trust.
Finding hosts
Hosts advertise themselves on your local network, so clients can discover them automatically instead of needing an IP address. The native clients and Moonlight both list hosts they find on the LAN.
Multiple devices at once
A host can stream to several clients simultaneously — your laptop and your TV both viewing (and controlling) the desktop, each at its own resolution. See Multiple devices.