Configuration
The host.env settings — compositor, resolution, bitrate, input — and how to tune them.
The host reads its settings from ~/.config/punktfunk/host.env (a simple KEY=value file). Your
setup guide gives you a starting host.env for your desktop; this page is the
reference.
Session settings
These tell the host which desktop session to attach to. Your setup guide sets them for you.
| Setting | What it does |
|---|---|
WAYLAND_DISPLAY | The Wayland socket of your session (wayland-0 for a normal desktop). |
XDG_CURRENT_DESKTOP | Your desktop (GNOME, KDE). |
XDG_RUNTIME_DIR, DBUS_SESSION_BUS_ADDRESS | Needed when the host runs outside your interactive session (e.g. as a service). |
Core settings
| Setting | Values | Meaning |
|---|---|---|
PUNKTFUNK_COMPOSITOR | mutter · kwin · gamescope · wlroots | Which backend creates the virtual display. Match your desktop. |
PUNKTFUNK_VIDEO_SOURCE | virtual · portal | virtual creates a per-client display at its exact mode (the normal choice). portal captures an existing monitor instead. |
PUNKTFUNK_ZEROCOPY | 1 · 0 | GPU zero-copy capture→encode. Leave on; it falls back to a CPU path automatically. |
PUNKTFUNK_INPUT_BACKEND | libei · gamescope · wlr · uinput | How input is injected. libei for GNOME/KDE, gamescope for Bazzite. |
Resolution and refresh rate
You don't set these on the host — the client chooses them. When a device connects, the host creates a virtual display at that device's resolution and refresh rate. A 1080p60 laptop and a 1440p120 desktop each get their own. (With Moonlight, set the mode in Moonlight's settings; with the Apple app, it uses the device's display.)
Bitrate
The client requests a bitrate; the host encodes to it. To find a good value for your link:
- Apple app: use the built-in speed test (a host card's menu → Test Network Speed). It measures your link and suggests a bitrate, then applies it.
- Moonlight: set the bitrate in Moonlight's settings. Start moderate and raise it.
Multiple devices at once
A host can stream to several clients simultaneously — each gets its own virtual display at its own resolution. This is the natural way to put your desktop on a laptop and a TV at the same time (both see and control the same desktop).
The number of simultaneous streams is bounded by your GPU's encoder. Cap it with
--max-concurrent N on the host command line (default 4); extra clients wait until a slot frees.
Codec and FEC
- The host encodes HEVC (H.265) by default; AV1 is available for clients that support it.
- The native protocol adds forward error correction for lossy links.
PUNKTFUNK_FEC_PCT=Nsets the redundancy percentage (the default is sensible for a normal LAN).
Diagnostics
PUNKTFUNK_PERF=1logs per-stage timing (capture, encode, send) — handy when tuning latency.RUST_LOG=info(ordebug) controls log verbosity.