enricobuehler
c894c6f897
Nested games on the Bazzite host saw the wrong display: refresh capped at 60 Hz, the box's connected TV's EDID modes leaking in (DOOM landed on 2560×1440@60), and the resolution fixed at whatever the always-on session was launched at — the client's requested mode never reached the game. Root causes: the session-plus gamescope command has no --nested-refresh (Xwayland advertises 59.96 Hz for every mode), --prefer-output HDMI-A-1 makes gamescope read the TV EDID, and the ATTACH model launches one fixed-resolution session. New vdisplay path: PUNKTFUNK_GAMESCOPE_SESSION=<client> — the host LAUNCHES gamescope-session-plus headless AT THE CLIENT'S mode and relaunches it when the mode changes. Injected via a host-written GAMESCOPE_BIN wrapper (--nested-refresh $PF_HZ, the flag session-plus doesn't expose) + DRM_MODE=cvt (gamescope generates clean CVT modes at that refresh instead of the TV's EDID). The session runs as a transient `systemd-run --user` unit (clean cgroup teardown of the Steam tree); state lives in a host-lifetime static (MANAGED_SESSION), NOT in GamescopeDisplay (which is per-client-session) — so a same-mode reconnect REUSES the running session instantly (no Steam restart) while a different mode RELAUNCHES it (games can't change output mode live; a game/Steam restart on a mode change is unavoidable and acceptable). Reuses the existing node + EIS auto-discovery (find_gamescope_node / find_gamescope_eis_socket, factored into point_injector_at_eis) and the existing mid-stream Reconfigure → vd.create(mode) machinery — no protocol or m3 control-flow change. Validated live on bazzite (RTX 4090): games' Xwayland now advertises 5120×1440 @ 239.90 Hz as the preferred mode (was 59.96), the TV's 3840×2160/4096×2160@60 modes are gone, frames stream; reconnect at 1920×1080@120 relaunches and games see that; same-mode reconnect reuses with no restart and frames flow instantly. scripts: host.env.example documents PUNKTFUNK_GAMESCOPE_SESSION (mutually exclusive with the legacy NODE=auto attach); punktfunk-steam-session.service marked deprecated (superseded — must not run alongside the host-managed path). Co-Authored-By: Claude Opus 4.8 (1M context) <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: docs/roadmap.md.
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.