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
5.4 KiB
HANDOFF — 2026-09-10 (evening)
Branch / Commit State
main HEAD currently = c45cbc9 (slice 10). Slice 11 is uncommitted in the working tree
(WebView2 capture cadence + de-throttle; see below). ahead of origin by 16, NOT pushing —
user ruling (2026-09-10): do not push until the web-overlay transparency AND audio-silence
issues are addressed. Both are open (see Still Open). Milestone tag milestone-recording-timing
(annotated) on c45cbc9 — rollback point: git reset --hard milestone-recording-timing.
Timing saga — CLOSED (verified)
- slice 9
bd396e4: duration == wall time (count-based CFR, deadline never rebased,-reremoved). - slice 10
c45cbc9: boundedChannelencoder queue + drop-newest policy + burned-in dot-matrix frame counter (bottom-right). Verified on two takes (ty-20260910-0949…-2.mp4, 2383 frames 39.92s;ty-20260910-0957…-2.mp4, 2270 frames 38.05s): every frame decodes, counter advances +1/frame, zero gaps/dups. Content cadence both: median 2 frames, max gap 9, longest frozen run 8 (133ms). User: "I think we're good on this issue" → timing CLOSED.
The web-overlay threads (the active push-gate work) — Slice 11 in tree
Two user-reframed symptoms converged on ONE root cause and one change is in the tree (uncommitted):
- "The widget is an animated resource — the animation looks too slow."
- (earlier) "image renders but the transparent pixels are black."
Root cause of #1 (code-proven): the recording is 60fps, but the WebView2 capture loop was a blind
100ms DispatcherTimer = 10Hz → the widget's motion is sampled 6× under rate → repeated-frame
slow-mo. PLUS Chromium hidden-page throttling (rAF parked, timers→1s; WebView2Feedback#1172/#3070)
when the off-screen page's host window is unfocused/covered. #2 remains UNVERIFIED (the diagnostic
PNG+alpha log is bound to the FIRST capture ever = the initial about:blank doc, so it can never see
the widget — 5/5 sessions logged alpha=0 blank; instrument is blind, not the capture).
Slice 11 (uncommitted, files below):
Services/CaptureScheduler.cs(new): per-session dispatcher timer that DROPS ticks while a capture is in flight (latest-wins, never queues). Interval owner-configurable: 33ms recording / 200ms idle.Services/WebView2Manager.cs: scheduler replaces the raw timer; sharedCoreWebView2Environmentcreated BEFOREEnsureCoreWebView2Asyncwith--disable-backgrounding-occluded-windows --disable-renderer-backgrounding --disable-features=CalculateNativeWinOcclusion(GetEnvironmentAsync);SetCaptureInterval(int); capture-cost telemetry (first 30 captures/ session → startup.log).ViewModels/MainViewModel.Streaming.Operations.cs:SetCaptureInterval(33)on record/stream start,(200)on stop.ytLive.Tests/WebView2ManagerTests.cs: ONE testCaptureScheduler_Drops_Ticks_While_Capture_InFlight_And_Resumes(deterministic TCS-driven, no WebView2 runtime).- Docs same commit:
ai.mdslice 11,MyMistakes.mdrecipe "web widget captured at 10Hz…".
Suite: 290/291 pass — sole failure the PRE-EXISTING Composite_FullScene_MasterPixels pixel
(1380,700) cyan-vs-magenta (out of scope; fails with any fix stashed).
NEXT STEP (the take that closes the web animation speed)
- Commit slice 11 (scope-check first; commit cites WebView2Feedback#1172/#3070/#20 + Chrome-88 blog).
- Run a normal recording with the animated widget on screen for ~20s. Expected:
- startup.log:
capture #1..#30 … took Nmslines (tell us the per-capture cost) — this decides whether 30Hz stays or drops to ~20Hz; alsoFramePump stats:should show no new dropped-frame growth vs before (GC-churn check). - Widget animation ~2-3× closer to real-time (10→30Hz).
- If it only became jittery instead of fast: check the FramePump dropped-frame counters.
- startup.log:
- Then, separately, the TRANSPARENCY verification (still open): re-point the first-capture dump/ alpha-log at a POST-PAINT capture of the real widget document (currently bound to about:blank) — the change that makes "are transparent margins real?" answerable. Intended next change.
Still Open
- Web transparency UNVERIFIED — the diagnostic instrument is blind (fires on about:blank); last known visual state take-25 black box; user's "transparent pixels black" may be the opacity bug OR the preview surface. Needs the post-paint instrument fix (above) then a take. Push gate reason #1.
- Audio silence — silent audio (−91dB full-length) in take-15; named-pipe audio delivers ~nothing. Queued follow-up. Push gate reason #2.
- Pre-existing compositor pixel test failure (never in scope).
Landmines
- testhost shares startup.log with app — filter by time when triaging.
- Locked DLLs:
taskkill //F //IM testhost.exe //IM ytLive.exebefore rebuild. - Build/tests via
/mnt/c/Program Files/dotnet/dotnet.exe build …/… vstest "C:\Users\gramp\Documents\Code\projects\ytLive\ytLive.Tests\bin\Debug\net8.0-windows10.0.19041.0\ytLive.Tests.dll". - Probing recordings:
/mnt/c/Program Files/Krita (x64)/bin/ffmpeg.exe/ffprobe.exe(Windows-form paths). tools/ticker: constant ~+982ms offset on the FIRST line is cosmetic.- WebView2Manager Ran into LOH churn worry: each capture allocs a BitmapImage raster (~8.3MB) that is garbage per capture; at 30Hz that's ~250MB/s LOH on the UI thread → potential gen2 pauses showing as FramePump dropped frames. Slice 12 candidate if the take's stats show it.