New crate crates/punktfunk-client-linux (binary punktfunk-client), the native Linux client on the Option A architecture (2026-06-12 research): - GTK4/libadwaita shell linking punktfunk-core directly (no C ABI): mDNS host list, TOFU fingerprint prompt, SPAKE2 PIN pairing dialog, preferences (mode/bitrate/gamepad/shortcut capture), stats overlay, --connect host[:port] for scripting. - Video: FFmpeg software HEVC decode (LOW_DELAY, slice threads) -> RGBA -> GdkMemoryTexture inside GtkGraphicsOffload (the dmabuf subsurface path lights up when VAAPI lands; black-background keeps fullscreen scanout-eligible). - Audio: Opus -> PipeWire playback stream, the host virtual-mic's adaptive jitter ring inverted. - Input: keyboard as the exact inverse of the host VK table (evdev keycodes, layout-independent; unit-tested), absolute mouse through the Contain-fit transform, WHEEL_DELTA(120) scroll, compositor shortcut inhibition while streaming, Ctrl+Alt+Shift+Q release chord, F11 fullscreen. SDL3 gamepad capture (single pad-0 model) + rumble and DualSense lightbar feedback on the same thread. - Session pump owns video+audio pulls; the gamepad thread owns rumble+hidout — possible because NativeClient's plane receivers are now mutexed, making it Sync (Arc-shared, compiler-verified per-plane contract instead of the ABI's manual assertion). - Linux-gated deps + a stub main keep cargo build --workspace green on macOS. Validated live against serve --native on this box: 1920x1080@60, locked 60 fps, capture->decoded p50 ~6.4 ms (software decode, debug build). Teardown keys off AdwNavigationPage::hidden — NavigationView push fires a transient unmap/map cycle that must not end the session. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
punktfunk
A ground-up low-latency desktop streaming stack, built Linux-first, with a shared Rust protocol core and native clients per platform.
punktfunk is a placeholder codename. The bet: ship a Linux virtual-display streaming
host that speaks the existing Moonlight protocol (every Moonlight/Artemis client works
day one), then break the ~1 Gbps FEC wall with a GF(2¹⁶) Leopard-RS transport as a
negotiated extension. See docs/implementation-plan.md.
Status
| Milestone | State |
|---|---|
M1 — punktfunk-core + C ABI |
✅ done & hardened (FEC, packetization, AES-GCM, session, adversarial-review fixes, punktfunk_core.h) |
| M2 — GameStream host → stock Moonlight | ✅ live end-to-end: pairing, RTSP, audio, per-client virtual output at native res, GPU zero-copy NVENC, gamepads |
M3 — punktfunk/1 native protocol |
✅ validated live: QUIC control + GF(2¹⁶) FEC/AES data plane, SPAKE2 PIN pairing, mid-stream mode renegotiation |
| M4 — client decode + present (Apple) | 🟡 macOS first light: AnnexB→VideoToolbox HEVC on glass + input/pairing over punktfunk/1 (clients/apple); iOS + presenter next |
| Web console + management API | ✅ TanStack web console (web/) over the OpenAPI mgmt API: host status, paired devices, on-demand native pairing (arm → show PIN) |
The GameStream host works with a stock Moonlight client — validated live on NVIDIA
(RTX 5070 Ti & RTX 4090, driver 595): trust-on-first-use pairing that persists, an app
catalog, RTSP/ENet/audio, and video at the client's exact resolution and refresh via a
per-session virtual output (KWin, gamescope, Mutter, Sway backends), encoded with GPU
zero-copy (dmabuf → CUDA/Vulkan → NVENC) at up to 5120×1440@240. The native
punktfunk/1 protocol adds a QUIC control plane and a GF(2¹⁶) Leopard-FEC + AES-GCM data
plane (p50 ~0.8 ms capture→reassembled at 720p120), with a SPAKE2 PIN pairing ceremony. Both
run from one process (serve --native), managed through a REST API + web console. Builds
against FFmpeg 7 or 8; deployed live on Bazzite. Full status: CLAUDE.md;
roadmap, setup guides & progress: the docs site (docs-site/ — Fumadocs;
bun run dev), with the canonical roadmap and
status there. Design notes stay in docs/.
Layout
crates/
punktfunk-core/ protocol · FEC · pacing · crypto · quic — the C ABI (lib + cdylib + staticlib)
punktfunk-host/ Linux host: vdisplay · capture · encode · inject · gamestream · m3 · mgmt · native_pairing
punktfunk-client-rs/ punktfunk/1 reference client (M3 headless; M4 adds decode+present)
clients/{apple,android}/ native client scaffolds (import punktfunk_core.h); apple = macOS first light
web/ TanStack web console (host status · paired devices · pairing) over the mgmt API
packaging/ Fedora/Bazzite RPM · bootc image · COPR (see packaging/bazzite/README.md)
include/punktfunk_core.h cbindgen-generated C header (checked in)
tools/{latency-probe,loss-harness}/ measurement (plan §10)
docs/{implementation-plan,roadmap,windows-host,dualsense-haptics}.md
Build & test
cargo build --workspace # green on Linux and macOS
cargo test --workspace # unit + loopback + proptest + C ABI harness
cargo clippy --workspace --all-targets
cargo run -p loss-harness # FEC loss-resilience sweep (no network needed)
bash crates/punktfunk-core/tests/c/run.sh # standalone C-ABI link+round-trip proof
The C header regenerates from crates/punktfunk-core/src/abi.rs on every build (cbindgen via
build.rs) into include/punktfunk_core.h.
Design invariants
- One core, linked everywhere. Protocol/FEC/crypto/pacing live in
punktfunk-coreexactly once, exposed over a stable, versioned C ABI (punktfunk_abi_version(),PunktfunkConfigcarries its ownstruct_size). - No async on the hot path. The per-frame pipeline uses native threads only;
tokio/quinnare gated behind the off-by-defaultquicfeature (control plane only). - FEC is the wall-breaker. GF(2⁸) (≤255 shards/block) for Moonlight compat; GF(2¹⁶) (≤65535 shards/block, SIMD, O(n log n)) to push past ~1 Gbps.
License
MIT OR Apache-2.0.