punktfunk/clients/linux

punktfunk — Linux client

The native Linux app for streaming a punktfunk host to your desktop, laptop, or Steam Deck. It's a clean GTK4/libadwaita app that finds hosts on your network, pairs with a PIN, and puts a low-latency stream on glass at your display's own resolution and refresh rate.

Built in Rust, it links the shared punktfunk-core directly (no C ABI) and speaks the fast punktfunk/1 protocol — QUIC control plane, GF(2¹⁶) FEC + AES-GCM data plane.

Features

• Zero-copy hardware decode — FFmpeg VAAPI decode → DRM-PRIME dmabuf → GdkDmabufTexture (Tier-1 zero-copy on Intel and AMD), with an automatic software-HEVC fallback on NVIDIA or when VAAPI is unavailable.
• Your display's native mode — the host builds a virtual output at exactly your WxH@Hz; no scaling, no letterboxing. Steady 60 fps at 1080p60, ~6 ms capture→decoded on the LAN.
• Audio both ways — PipeWire playback with a jitter ring, plus mic uplink to the host.
• Full controller support — SDL3 gamepads with rumble and DualSense fidelity (lightbar, player LEDs, touchpad, motion, adaptive-trigger replay). Click-to-capture keyboard and mouse, with a release chord (Ctrl+Alt+Shift+Q) and focus-loss release.
• Find hosts automatically — mDNS discovery lists hosts on your LAN; saved hosts persist. First connect does a one-time SPAKE2 PIN pairing (or TOFU on trusted LANs), then reconnects on a pinned identity.
• Per-host speed test to pick a bitrate, plus compositor and mode preferences in Settings.
• Game library browser (experimental, off by default) — "Browse library…" on a saved host shows its games (Steam + custom) as a poster grid; click one to launch it in the session. Fetched from the host's management API over mTLS — paired devices are authorized by their certificate, no extra host setup.
• Gamepad library launcher (--browse host) — a console-style, controller-driven coverflow of a paired host's library (drifting aurora backdrop, center-focus posters, button hints): A plays the focused title, B quits, L1/R1 jump. Built for the Steam Deck plugin's "Open library" launch; session end returns to the launcher. Arrow keys/Enter/Esc drive it too (no pad needed).

Get it

Most people should install a package rather than build from source:

Distro	Install
Flatpak (any distro, Steam Deck)	io.unom.Punktfunk — see packaging/flatpak
Ubuntu / Debian (apt)	sudo apt install punktfunk-client (after adding the repo)
Fedora / Bazzite (rpm)	rpm-ostree install punktfunk-client
Arch (PKGBUILD)	see packaging/arch

Per-device install steps and pairing walkthrough: docs.punktfunk.unom.io/docs/install-client.

Build & run from source

Requires GTK ≥ 4.16, libadwaita ≥ 1.5, FFmpeg 7 or 8 (with VAAPI for hardware decode), PipeWire, and SDL3 (with hidapi) development packages.

# from the repo root
cargo run -p punktfunk-client-linux                 # launch the app
cargo run -p punktfunk-client-linux -- --connect HOST[:PORT]   # skip the host list and connect
cargo run -p punktfunk-client-linux -- --browse HOST           # the gamepad library launcher

The binary is named punktfunk-client — the relm4/libadwaita desktop shell (hosts, pairing/trust, settings, the desktop library page). Every stream and the console game library run in the sibling punktfunk-session Vulkan binary; the shell spawns it for connects, and --connect/--browse on the shell exec it directly (so the Decky wrapper keeps working unchanged). Headless flags stay in the shell: --pair <PIN> --connect host[:port] (pairing ceremony), --wake host[:port], and --library host[:mgmt_port] (print a host's game library).

Layout

src/
  main.rs · app.rs        entry point, relm4 AppModel (window, trust gate, session child
                          lifecycle, typed messages), primary menu, CSS
  cli.rs                  headless paths (--pair/--wake/--library), the --connect/--browse
                          exec handoff to punktfunk-session, screenshot scenes
  ui_hosts.rs             hosts page component (FactoryVecDeque cards, saved + discovered
                          grids, add-host dialog, banner)
  ui_library.rs           game-library poster grid (per-host, launches titles)
  ui_trust.rs             TOFU / PIN-pairing / request-access dialogs
  ui_settings.rs          resolution · refresh · decoder · bitrate · compositor · mic
  spawn.rs                the session-child plumbing (stdout contract → AppMsg)
tools/screenshots.sh      store screenshot capture (app self-capture; Xvfb fallback)

The UI-agnostic plumbing — session pump, FFmpeg decode, PipeWire audio, SDL3 gamepads + keymap, trust store, mDNS discovery, library client, Wake-on-LAN — lives in crates/pf-client-core, shared with the Vulkan session binary.

Related

• Documentation — quick start, pairing, troubleshooting
• Steam Deck plugin — launches this client fullscreen in Gaming Mode
• Project README — the host, the other clients, and how it all fits together