Picker speed (Phase 1+2):
- screen_sources.rs split into list_screen_sources (metadata only,
returns in ~10ms) + capture_screen_source_thumbnail (single source,
by id). ScreenSourcePicker now shows names + placeholders instantly
and streams thumbnails in as each capture lands. Total wall-clock
is bounded by the slowest source instead of the serial sum.
- enumerate_screen_sources kept as a dead_code fallback so any
rollout regression can switch the frontend back without code loss.
Native capture (Phase 3):
- New src-tauri/src/screen_capture.rs. start_screen_capture spawns a
Rust thread per share that grabs frames via xcap, downscales to the
user's quality preset, JPEG-encodes at Q72, and streams each frame
through a Tauri Channel<FramePayload>. stop_screen_capture signals
the stop flag and joins the worker.
- Worker re-resolves the xcap handle inside the thread because
xcap::Window holds a !Send HWND — passing the source id string
across the thread boundary sidesteps that.
- New lib/screenCapture.ts: decodes each frame into an ImageBitmap,
draws to an offscreen canvas, exposes canvas.captureStream() as the
MediaStream LiveKit publishes. Latest-wins frame queue drops stale
frames when the JS side falls behind the Rust producer. 3s first-
frame timeout so a silently-failing source (locked screen, DRM
window) surfaces as a clean NativeCaptureUnavailable and we fall
back to getDisplayMedia.
- CallContext.startScreenShare takes the native path first when the
picker provided a sourceId and system audio wasn't requested. The
old chromeMediaSourceId attempt and final setScreenShareEnabled
fallback stay in place for the audio case + non-Tauri runtimes.
- stopScreenShare kills the native handle first, then unpublishes any
manually-published ScreenShare/ScreenShareAudio tracks, then falls
back to setScreenShareEnabled(false). disconnectRoom also stops
the handle so we don't leak Rust threads across calls.
Scope note: native path is video-only. System-audio capture needs
WASAPI-loopback (Windows) or ScreenCaptureKit-audio (macOS); until
those are wired, requesting audio in the picker falls through to
the getDisplayMedia path and shows the OS picker for that one case.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
byGalax