enricobuehler
3ea096ace9
The shared-core architecture pays off: platform clients now link ONE Rust library that does the entire lumen/1 protocol, and only add decode/present/input on top. lumen-core: - client.rs (quic feature): NativeClient — QUIC handshake + UDP data plane + input datagrams on internal threads; embedder surface = connect / next_frame / send_input. - abi.rs: lumen_connect / lumen_connection_next_au (borrow-until-next-call, matching lumen_client_poll_frame semantics) / lumen_connection_send_input / lumen_connection_mode / lumen_connection_close. Guarded in the generated header by LUMEN_FEATURE_QUIC (cbindgen [defines] mapping), so the checked-in header is stable across feature sets. - error.rs: append-only LumenStatus additions Timeout (-9) and Closed (-10). - TESTED end-to-end through the C ABI: in-process lumen/1 host, lumen_connect pulls 25 byte-verified frames, sends input, closes (m3.rs::c_abi_connection_roundtrip). Apple client (clients/apple — SCAFFOLD, written on Linux, first Xcode build pending): - scripts/build-xcframework.sh: cargo per Apple target → universal staticlib + header (LUMEN_FEATURE_QUIC pre-defined) + modulemap → LumenCore.xcframework. - Package.swift (LumenKit) + Swift sources: LumenConnection (ABI wrapper), AnnexB (in-band VPS/SPS/PPS → CMVideoFormatDescription, Annex-B → AVCC CMSampleBuffers with DisplayImmediately), StreamView (SwiftUI over AVSampleBufferDisplayLayer — stage-1 presenter that hardware-decodes compressed HEVC itself), InputCapture (GCMouse raw deltas + GCKeyboard HID→VK). - README.md is the full handoff for the next (Mac-side) agent: build steps, ABI contract, first-light test recipe against the Linux host, stage-2 (VT+Metal pacing) plan, and the known host-side gaps (single-session m3-host, no lumen/1 audio yet, gamepad kinds not yet routed in m3's injector, seed-stage trust). Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
lumen
A ground-up low-latency desktop streaming stack, built Linux-first, with a shared Rust protocol core and native clients per platform.
lumen 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 — lumen-core + C ABI |
✅ done & tested (FEC, packetization, crypto, session, lumen_core.h) |
M0 — pipeline spike (wlroots→PipeWire→NVENC→file→lumen-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; lumen-client-rs scaffolded |
| M5 — Apple client | ⬜ scaffolded (clients/apple) |
lumen-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: lumen-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 lumen_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/
lumen-core/ protocol · FEC · pacing · crypto — the C ABI (lib + cdylib + staticlib)
lumen-host/ Linux host: vdisplay · capture · encode · inject · gamestream · mgmt
lumen-client-rs/ reference client (M4): VAAPI decode + wgpu present
clients/{apple,android}/ native client scaffolds (import lumen_core.h)
include/lumen_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/lumen-core/tests/c/run.sh # standalone C-ABI link+round-trip proof
The C header regenerates from crates/lumen-core/src/abi.rs on every build (cbindgen via
build.rs) into include/lumen_core.h.
Design invariants
- One core, linked everywhere. Protocol/FEC/crypto/pacing live in
lumen-coreexactly once, exposed over a stable, versioned C ABI (lumen_abi_version(),LumenConfigcarries 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.