enricobuehler 03a6a67354 feat: M2 P1.7 — libei input backend (portable to KWin/GNOME)
Add a second input-injection backend that works on compositors implementing
the org.freedesktop.portal.RemoteDesktop interface (KWin, GNOME/Mutter), where
the wlroots virtual-input protocols are absent. Uses ashpd 0.13 to open a
RemoteDesktop session + EIS fd and reis 0.6.1 to drive it as an EI sender:
bind pointer/keyboard/scroll/button capabilities and, per device,
start_emulating → emit → frame. Runs on a dedicated thread with its own tokio
runtime (the portal session + EIS connection must stay alive and the event
stream must be polled continuously); open() returns immediately so a slow or
denied portal can never freeze the ENet control thread, with events enqueued
over an unbounded channel until devices resume.

Backend now auto-selects per session (inject::default_backend): wlr on Sway,
libei on KDE/GNOME; LUMEN_INPUT_BACKEND overrides. Refactor inject.rs into the
inject/{wlr,libei}.rs layout matching the capture/encode convention. Keyboard
codes are evdev (the same space our VK→evdev table produces) and the compositor
supplies the keymap, so no keymap upload and no modifier serialization — pressing
the modifier keys Moonlight sends is enough.

Add a `lumen-host input-test` subcommand that injects a scripted mouse+keyboard
pattern through the session backend, so input injection can be validated without
a Moonlight client.

Live-validated on headless KWin (Plasma 6.4): mouse motion, left click, and the
'A' key inject correctly and are delivered to the focused client.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
2026-06-09 13:58:41 +00:00

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-core exactly once, exposed over a stable, versioned C ABI (lumen_abi_version(), LumenConfig carries its own struct_size).
  • No async on the hot path. The per-frame pipeline uses native threads only; tokio/quinn are gated behind the off-by-default quic feature (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.

S
Description
next gen game streaming - built using rust, back compatible with game stream clients, and supporting virtual displays for kde/kwin, gnome and gamescope.
Readme 16 MiB
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