The 12:35 live session proved the decoder healthy (frames=240 audioChunks=156 failed=False both clips, alert audio in the mix at peakMix 0.277→0.733) yet the creator still saw 'no video plays / you lost the video'. Root cause: pacing, not decode. AlertClipDecoderFor built the decoder with no frameRateProbe, so RunAsync computed frameDuration = TimeSpan.Zero and RunVideoAsync's pace step was dead code — all 240 frames of the 10s clip dumped through the pipe in the first ~1-2s (130MB as fast as ffmpeg read), then the box froze on the LAST frame while audio chunk-paced its real-time ~7.8s. Reads exactly like a dead decoder on screen. The media path already wired this seam (MainViewModel.cs:308); the alert factory never supplied one. Derivative fix (media/decoder plumbing, cited in broad consensus of players): pass FfmpegFrameRateProbe into the per-play alert decoder exactly like MediaVideoSource does. Good Dog: AlertClipDecoderTests.AlertClipDecoder_PacesVideoFramesToTheProbedFrameRate — real AlertClipDecoder via the fake-process/fake-probe/delay-recorder seam; red on the old factory (zero pacing delays), green with the probe (one ~10ms delay per frame at 100fps). Full suite 321/322, one known-env flake (RealMouseDrag reorder). Docs in this commit: task-47 addendum, MyMistakes.md (a decoder that drops data faster than wall-clock looks identical to a dead one), HANDOFF rewrite.
7.1 KiB
HANDOFF — 2026-09-26 (TASK 47: crash + silent-void + video-pacing all fixed; 4 local commits, NOT pushed)
Branch / Commit State
main — four local commits ahead of origin/main (= ecb329e), NOT pushed (awaiting the
creator's go / milestone signal):
a11b15e— TASK 47 alert box video (built-in/custom clip + read-time fade + message ticker + unity audio) +AlertLayerVideoTests(fake decoder, 0 warnings, 319/319 green).7b940b6— crash fix: AlertOverlayLayer marshals the chat-poller seam to the UI thread (regression test red pre-fix / green post-fix). Full suite 320/320.80038ff— silent-decoder fallback + diagnostics (no-frame grace 1.0s → six-animation; BeginClip/RunAsync logging). Full suite 321 with the known env flake (RealMouseDrag reorder failing while windows are up).- (uncommitted next — this session) — video pacing fix (below). Scope:
ViewModels/MainViewModel.Chat.cs,ytLive.Tests/AlertClipDecoderTests.cs(new), docs (task-47 addendum,MyMistakes.md, this file). Test green; build 0 warnings;scope-check.shpending, then commit.
✅ Crash fixed (7b940b6)
The creator's first live session: test-tab alerts DID fire (11:21 startup.log: alert-clip audio in
the mix, peakMix 0.375 → 0.891 with mic+loop at 0.000) but the app crashed at 11:22:01.301 on
the first REAL polled message: Must create DependencySource on same Thread as the DependencyObject
in DataBindEngine.ProcessCrossThreadRequests. AlertOverlayLayer.OnMessageReceived had no
UI-thread marshal (ChatOverlayLayer has one); it ran RefreshAlertPreviews → UpdatePreview on
the MTA poller thread and stamped alertBox.VideoImageSource (INPC + WPF-bound) with a
WriteableBitmap created there. Fix + Good Dog regression test
OnMessageReceived_FromPollerThread_MarshalsPreviewWritesToTheUiThread (red/green verified).
✅ "Nothing in the alert box" void — fixed (80038ff)
After the crash fix: On-Air → test → remove and re-add the Stream Alerts layer → TEST event →
procs in chat but nothing in the alert box. startup.log 11:44 peakMix 0.105 (no alert audio)
vs 11:21's 0.375–0.891. Every stage of the clip path was silent by design; a decoder whose Start()
succeeds but yields no frames AND no audio left _clip != null with _latestClipFrame == null
→ blank box forever. Fix: no-frame grace (1.0s) in AlertOverlayLayer.Advance → tear down + same
alert as six-animation; BeginClip/RunAsync diagnostics stop the silence. Good Dog:
SilentDecoder_FallsBackToTheAnimationAfterTheNoFrameGrace.
✅ "No video plays" — decoder HEALTHY, video UNPACED — fixed (this unit)
Creator repro after 80038ff (12:35 session): still "no video plays in the web-alert box", "like
you lost the video" — but the new diagnostics PROVED the decoder healthy: Alert clip start: box …
→ Alert clip end: … frames=240 audioChunks=156 failed=False twice, alert audio in the live mix
(peakMix 0.277 → 0.733, mic/loop 0.000). Root cause was pacing, never decode:
AlertClipDecoderFor (MainViewModel.Chat.cs:113) built the decoder with no frame-rate probe →
RunAsync computed frameDuration = TimeSpan.Zero → RunVideoAsync's pace step
(if (frameDuration > 0)) was dead code → all 240 frames of the 10s clip dumped through the pipe
in the first ~1-2s (130MB as fast as ffmpeg read), then the box sat frozen on the LAST frame while
the audio pipeline paced 156 chunks at real-time ~7.8s. Reading exactly like "no video / you lost
it". The media path already had the seam wired (MediaVideoSource gets
frameRateProbe: new FfmpegFrameRateProbe(…), MainViewModel.cs:308) — the alert factory just
never passed one.
Fix (uncommitted): AlertClipDecoderFor passes
frameRateProbe: new FfmpegFrameRateProbe(new FfmpegLocator(), () => new FfmpegDecodeProcess()) so
video paces at the clip's native ~24fps (10s real-time) in lockstep with audio. Good Dog test
AlertClipDecoderTests.AlertClipDecoder_PacesVideoFramesToTheProbedFrameRate drives the REAL
AlertClipDecoder through the media-style fake process + fake probe + recorded delay seam
(3 frames at 100fps → one ~10ms delay per frame; red on the old factory, green now). Full suite
321/322 (one known-env flake). MyMistakes.md: a decoder that drops data faster than wall-clock
looks identical to a dead decoder on screen — "plays but you don't see it" is a PACING bug before
it's a decode bug. Rules: never ship a pipe whose frameDuration can be zero; check pacing
(bytes/s vs wall-clock) before re-auditing the codec.
Follow-ups queued (NOT done in this unit)
- TASK 3 item 20 persistence half — canonical
RewardEventsSQLite table +superChatEvents.list(30-day) backfill + session-report rollup (still in-memory only). - TASK 3 item 16 (Text source); TASK 40 units A/C/D; TASK 32–36; TASK 12 master limiter — queued.
- If the alert box is STILL "no video" after this fix + relaunch: check the 12:35-style
Alert clip end: … frames=240line (now logged) — a healthy decode with no visual means the painter/render path, not the decoder; the creator's Live scene also has a WebSource "Web Resource-0" bottom-right — confirm which element they watch when describing the "web-alert / stream-alerts" box. - The known pump stall (
render=full-render … totalMs=147, ~6fps worst) is recorded as a pre-existing perf item, NOT part of this unit.
Around the task (carried facts)
- RealMouseDrag tests no-op while a game/fullscreen window steals the mouse — close fullscreen windows before full-suite runs; passes in isolation.
- Test-env trap: saved OAuth session loads synchronously → force
vm.IsConnectedin signed-in tests. subscriberCountYPP slice 2 needs re-consent — do not merge with other units.MARCOM.md/MONETIZATION.mdgitignored — never commit.- API facts (TASK 44 + 45): liveChatId unavailable until broadcast live;
400 MISSING_REQUIRED_FIELDfromliveChat/messages.insert= wrong body shape (missingsnippet.type). - TASK 47 sticky facts: bgra from ffmpeg is opaque (alpha=255); audio pipe = carry-buffer loop;
default clip =
%TEMP%\ytLive-alert-{id}.mp4; decoder per-play; DB staysuser_version 10. - Every committed change needs a close + relaunch of the running app to be seen.
Next step
- Commit this unit with the declared scope
./scripts/scope-check.sh "ViewModels/MainViewModel.Chat.cs" "ytLive.Tests/AlertClipDecoderTests.cs". - Push the four local commits at the creator's go / milestone signal.
- Creator to relaunch and re-run the repro — with the probe wired the clip plays real-time
(~10s of motion, not a blur + frozen frame); the
Alert clip end:line confirms decode health.
Critical working rules (unchanged, still binding)
- Good Dog = ONE integration test per change. Scope lock +
./scripts/scope-check.shbefore commit. - Windows dotnet host for all WSL builds (
/mnt/c/Program Files/dotnet/dotnet.exe, quoted paths). - 0 warnings on real clean builds. One commit = fix + its memory (task doc, MyMistakes, handoff).
- No menus/polls with the creator; decisions asked once then held; do the work, then report.