5e78065c2d
The recording is 60fps but WebView2 capture was a blind 100ms DispatcherTimer = 10Hz; each captured web frame repeated ~6x into the file caps web animation at the capture rate, not the page's (user: 'the animation appears to be too slow'). - New CaptureScheduler (Services/CaptureScheduler.cs): per-session dispatcher timer that DROPS a tick while a capture is in flight (latest-wins, never queues) — the guard that makes a higher cadence safe: concurrent full-HD PNG CapturePreviewAsync calls (~10-30ms each, slow per WebView2Feedback#20) would stack CPU and publish stale-after-fresh. Effective cadence = max(interval, capture duration). - Cadence: SetCaptureInterval(33) on record/stream start, (200) idle — applied via MainViewModel.Streaming.Operations.cs. - De-throttle the hidden page: shared CoreWebView2Environment created BEFORE EnsureCoreWebView2Async with --disable-backgrounding-occluded-windows --disable-renderer-backgrounding --disable-features=CalculateNativeWinOcclusion. Off-screen WebView2 is a hidden page when the host window is unfocused/covered and Chromium then parks rAF and clamps timers to ~1s (WebView2Feedback#1172/#3070, Chrome-88 timer-throttling blog). - Telemetry: first 30 captures per session log elapsed ms (PNG encode + decode) to startup.log — that decides whether ~30Hz stays or drops to ~20Hz; the FramePump drops frames (never time-lapses, slice 10) if UI-thread GC churn starves it. - ONE test: CaptureScheduler_Drops_Ticks_While_Capture_InFlight_And_Resumes (deterministic TCS-driven, no WebView2 runtime). Suite 290/291 — sole failure the pre-existing compositor pixel test. - Docs same-commit: ai.md slice 11, MyMistakes.md, HANDOFF. References: https://github.com/MicrosoftEdge/WebView2Feedback/issues/1172 https://github.com/MicrosoftEdge/WebView2Feedback/issues/3070 https://github.com/MicrosoftEdge/WebView2Feedback/issues/20 https://developer.chrome.com/blog/timer-throttling-in-chrome-88