enricobuehler
136390514d
punktfunk-host builds unchanged against either FFmpeg 7.x (libavcodec 61) or 8.x (libavcodec 62) — ffmpeg-sys-next auto-detects the system version, and the host's ffmpeg FFI only touches long-stable APIs. Confirmed by building + running live on a Bazzite F43 box (FFmpeg 7.1.3): full gamescope capture → zero-copy dmabuf→CUDA → NVENC H.265 at 1280x720x60, p50 ~0.96 ms. Just doc/spec accuracy, no code change: - encode/linux.rs + CLAUDE.md: drop the "FFmpeg 8 only" claim; note 7.x/8.x both work. - rpm spec: add the missing zero-copy GPU build deps the link actually needs — pkgconfig(gl) + pkgconfig(gbm) (mesa) — and document that -lcuda needs libcuda.so at link time (NVIDIA host, or the CUDA toolkit stub on a headless COPR/koji builder). Tracked for a proper fix: make the cuda/gbm/GL FFI dlopen-based like khronos-egl so the RPM builds on a GPU-less host. 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 & tested (FEC, packetization, crypto, session, punktfunk_core.h) |
M0 — pipeline spike (wlroots→PipeWire→NVENC→file→punktfunk-core) |
✅ done & verified on NVIDIA (RTX 5070 Ti / driver 595) |
| M2 — P1 host → stock Moonlight | 🟡 capture+encode landed in M0; pairing/RTSP/vdisplay pending |
| M3 — measurement harness | 🟡 tools/loss-harness runs; latency-probe scaffolded |
| M4 — P2 transport + Rust client | 🟡 GF(2¹⁶) core done; punktfunk-client-rs scaffolded |
| M5 — Apple client | 🟡 macOS first light: HEVC on glass + input over punktfunk/1 (clients/apple) |
punktfunk-core is complete and verified: it builds and its full test suite (FEC recovery,
loopback round-trip under loss, property tests, and a C ABI harness) passes on
macOS/aarch64. M0 is done: punktfunk-host captures a headless wlroots output via the
ScreenCast portal + PipeWire, encodes it with NVENC, writes a playable H.265 file, and
round-trips every access unit through a punktfunk_core host→client session (see
docs/linux-setup.md). M2 is in flight: the GameStream control plane (gamestream/) and
the management REST API (mgmt.rs, OpenAPI spec in docs/api/) are implemented; the
remaining Linux host backends (KWin/Mutter virtual displays, libei input) are
#[cfg(target_os = "linux")] seams — defined and compiling, implementations pending.
Layout
crates/
punktfunk-core/ protocol · FEC · pacing · crypto — the C ABI (lib + cdylib + staticlib)
punktfunk-host/ Linux host: vdisplay · capture · encode · inject · gamestream · mgmt
punktfunk-client-rs/ reference client (M4): VAAPI decode + wgpu present
clients/{apple,android}/ native client scaffolds (import punktfunk_core.h)
include/punktfunk_core.h cbindgen-generated C header (checked in)
tools/{latency-probe,loss-harness}/ measurement (plan §10)
docs/implementation-plan.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.