enricobuehler
278a6330de
A stock Moonlight client now gets video + full input + AUDIO from the from-scratch GameStream host (verified live end-to-end on a macOS client). Audio (audio.rs, audio/linux.rs, gamestream/audio.rs): - Capture the default PipeWire sink's monitor (system output) as interleaved f32 stereo @ 48kHz via stream.capture.sink, on its own thread. - Opus-encode 5ms/240-sample stereo frames (RESTRICTED_LOWDELAY, CBR) and send as GameStream RTP audio: 12-byte BE RTP_PACKET (packetType 97, seq+1/pkt, timestamp += packetDuration, ssrc 0) on UDP 48000, after learning the client endpoint from its port-learning ping. - Encrypt the Opus payload with AES-128-CBC (PKCS7), key = launch rikey, IV = BE32(rikeyid + seq) in [0..4]. Like the control stream, modern Moonlight always decrypts audio regardless of the negotiated flags — plaintext makes it log "Failed to decrypt audio packet" and play silence (diagnosed from the client log). RTP header stays in the clear. Scheme cross-checked against Sunshine stream.cpp/crypto.cpp + moonlight AudioStream.c. - Pace each frame to its 5ms slot (PipeWire delivers ~1024-frame buffers) to avoid bursts the client's jitter buffer hears as glitches. LUMEN_AUDIO_GAIN applies optional linear gain for quiet sources. - DESCRIBE SDP advertises the stereo Opus config (a=fmtp:97 surround-params). Video (stream.rs): pace at a steady ≤60fps, re-encoding the last captured frame when the compositor produces none. wlroots only emits on damage, so a static or slow-updating desktop previously starved the client into a "network too slow" abort; an unchanged frame costs a near-empty P-frame. Adds a non-blocking Capturer::try_latest (portal drains to the freshest queued frame). Misc: serialize pipewire init across the video + audio capture threads (pwinit.rs, std::sync::Once) to avoid a concurrent pw_init race. Deps: opus, cbc; libopus-dev in bootstrap-ubuntu.sh. 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). The remaining Linux host backends (KWin/Mutter virtual displays,
libei input, web/pairing) are #[cfg(target_os = "linux")] seams — defined and compiling,
implementations pending (M2).
Layout
crates/
lumen-core/ protocol · FEC · pacing · crypto — the C ABI (lib + cdylib + staticlib)
lumen-host/ Linux host: vdisplay · capture · encode · inject · web (cfg-gated)
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.