TASK 43's alert box grows a real video celebration. Per-alert IAlertClipDecoder
(ffmpeg bgra + f32le pipes, real-time paced, disposed at drain) plays the shipped
Assets/alert-default.mp4 (stamped into the Asset table at startup) unless the
creator picks their own file — path reference only, never stored in the DB; the
six AlertRenderer animations stay the fallback. ~0.3s fade rides the alpha
envelope on straight-source copies (EOF freeze-frames then fades out); audio
forwards to a new AudioMixer alert ring (8s, 48k stereo) drained at unity — no
duck, creator ruling — scaled by volume × fade. An auto-composed marquee ticker
('Funder — Super Chat · $10.00', 140px/s) scrolls top-of-frame via a
FramePump._alertTicker seam through Render/CompositeLayers, mixed into the cache
signature (dynamic overlay, never baked). New Stream Alerts section in LeftPanel.
Derivative-work references (how OBS/Streamlabs alert boxes do per-alert video):
- https://support.streamlabs.com/hc/en-us/articles/217741147-Setting-Up-Your-Streamlabs-Alerts (custom image/video per alert type + variations)
- https://obsproject.com/kb/stream-tutorial-2-alerts (alert overlay as an on-screen zone)
- https://streamlabs.com/content-hub/widgets/alert-box (per-event alert playback)
Good Dog: AlertLayerVideoTests drives a fake IAlertClipDecoder through the whole
lifecycle in one pass (custom path wins, decoder spawns/disposes, fade envelope
0→127→255, audio volume×fade, ticker scrolls, EOF fade-drain to idle). It caught
the clip branch of Advance not clearing _current before AdvanceToNext — the layer
stayed IsPlaying after drain (MyMistakes post-mortem).
Full vstest 319/319; clean build 0 warnings; scope check green.
Replace the external StreamElements feed with NATIVE YouTube events per the creator's
2026-09-23 question.
Chat parity half:
- YouTubeChatService decodes ALL SIX liveChat/messages event types into
ChatMessage.Kind (superChat/superSticker/newSponsor/membershipGifting/
giftMembershipReceived/memberMilestoneChat) — the four formerly-empty overlay
rows are real now — and re-arms its one-shot poll on the server's
pollingIntervalMillis (streamList connection semantics; clamp 1000-6000ms,
maxResults=2000). ParsePage internal static seam + ChatPage record for
deterministic tests; optional HttpClient ctor seam kept; InjectSimulatedMessage
(TASK 41) preserved.
Alerts half (creator rulings: one celebration zone, six UNIQUE animations, no
menus/polls, sub mention = chat row only, NO viewer count):
- New SourceType.AlertBox 'Stream Alerts' (one per layout, CanAddAlerts gate
mirroring chat; idle = transparent).
- AlertRenderer: six distinct branded animations (SuperChat slide-up/shine/
count-up, SuperSticker scale-pop, NewMember drop-in/flash, MemberGift slide-left/
chip-fan, GiftReceived confetti, MemberMilestone rise/growth-bar), every card
drawing the 'made with LlamaCasty!' brand line.
- AlertOverlayLayer: true component (Commit-G pattern) — queue (cap 10, drop tail
never stall), 33ms UI ticker, cache-first RenderFrame + UpdatePreview,
Advance(double) as the deterministic test clock; ChatEventKind.None rows never
enqueue.
- Wired: resolver RenderAlertBox, _alertLayer ctor + dispose, LoadLayout previews,
Add menu item (Controls/LeftPanel.xaml), TestSessionViewModel sims tagged
(member->NewMember, superchat->SuperChat).
Good Dog ONE integration test: AlertLayerTests (RealApp STA, real WPF raster) —
ParsePage classifies all six kinds + cadence fields; None rows enqueue nothing;
six events play pairwise-distinct moving frames then drain to null.
Gate: clean build 0 warnings; full suite 316/317, the one failure
(LayerReorderPersistenceTests.RealMouseDrag) repros on the clean tree — the
known environmental class (real-mouse-drag no-ops with a game/fullscreen window
focused).
References (OBS/overlay ecosystem):
- streamList semantics: https://developers.google.com/youtube/v3/live/docs/liveChatMessages/streamList
- OBS alert-box pattern (designated celebration zone, idle transparent): creator-chosen model
startup.log 2026-09-22 (user runs of the new build): ALL THREE session stops
logged 'Broadcast transition(complete) failed (403) invalidTransition → End
close-out: enableAutoStop will finish'. The old ai.md assumption ('invalidTransition
when autoStop already fired') was wrong — the blind complete POST races
YouTube/autoStop marking the broadcast complete (enableAutoStop=true is always
set, tests included), so a blind POST earned only the 403 + log noise. Per the
transition errors table, invalidTransition is a current-status problem and
complete is not gated on streamStatus (only testing/live are):
https://developers.google.com/youtube/v3/live/docs/liveBroadcasts/transition
Fix: EndBroadcastAsync pre-flights liveBroadcasts.list -> status.lifeCycleStatus
and skips the POST when the broadcast is already complete/revoked; an inconclusive
pre-check still posts (old behavior) rather than silently stranding a live
broadcast; still never throws (enableAutoStop finishes every skip).
Good Dog: EndBroadcast test rewritten to the one contract — live -> GET pre-check
+ POST transition (URL shape asserted); already complete -> zero transition POSTs;
inconclusive pre-check + 403 POST -> error string, never a throw. Full suite
315/315 (one-run audio/mouse timing flakes cleared), build 0 warnings.
Recipe recorded in MyMistakes.md; ai.md / Services index / TASK-9 note corrected.
startup.log 2026-09-22 (via the user's run of the new build): every session
start logged 'Stream health poll failed: The requested operation requires an
element of type String, but the target element has type Object'.
Root cause: GetStreamHealthAsync did status.healthStatus.GetString(), but the
real API nests it as status.healthStatus = {status, lastUpdateTimeSeconds,
configurationIssues[]} — an OBJECT, per the liveStreams reference
https://developers.google.com/youtube/v3/live/docs/liveStreams (checked the
docs before fixing, per derivative-work rule). Our flat-string fixture was the
wrong assumption since TASK 9; the report-by-exception health banner had been
silently dead.
Fix: read the nested healthStatus.status + nested configurationIssues[], tolerating
the legacy flat-string shape so nothing else breaks. Tests flipped to the real
object shape (the Good Dog for this change). Full suite 315/315, build 0 warnings.
Also recorded in MyMistakes.md (API-shape recipe) and ai.md/Services index. End-of-session
transition(complete) 403 invalidTransition (enableAutoStop fallback) observed on all three
2026-09-22 stops — separate racy-design issue, carried, not in this change.
The ~30Hz CapturePreviewAsync PNG poll capped real cadence at ~20Hz
(35–165ms full-HD encode+decode), so a 60fps widget still juddered at ~1/6
speed. Replaced polling with frame-driven capture of the composition
controller's root visual — the mechanism WebView2CompositionControl and
Flutter's webview_windows use (graphics_context.cc captures the root
surface_ visual via CreateGraphicsCaptureItemFromVisual; reference:
github.com/microsoft/Windows.UI.Composition.WinUI / flutter-internal
webview_windows). Frames now arrive at the renderer's own pace; capture
memory is epoch'd ring reuse + one crop-sized shared WriteableBitmap.
New Services/WebCaptureFrameSource.cs owns GraphicsCaptureItem + free-
threaded Direct3D11CaptureFramePool + session (Straight alpha readback,
per-frame FindContentBounds → CropBounds). WebView2Manager reworked around
per-session composition controllers + one UI-thread Compositor created via
the CoreMessaging CreateDispatcherQueueController P/Invoke (the 19041
projection lacks CreateOnCurrentThread); internal seam ctor
(Dispatcher, Func<string,IScreenCaptureSource>?) for hermetic tests.
CaptureScheduler.cs deleted; the three SetCaptureInterval cadence hooks
removed; InitWebView2() moved from MainWindow ctor to Loaded (a parent
HWND must exist for the composition controller); the hidden WebViewHostPanel
overlay deleted. TransparentBackgroundScript unchanged.
Tests: WebView2ManagerTests reworked — 4 control-size + scheduler tests
dropped, FindContentBounds tests moved to WebCaptureFrameSource, ONE
integration test (Frames_PublishCroppedPreview_And_CoalesceToLatest_CarryingCropBounds)
drives the seam with a FakeWebSource + background-STA DispatcherPump.
Suite 293/293, 0 warnings.
NOTE: composition path NOT yet verified on a device — the take is the
next step. Web work committed locally only (no push per standing rule).
Docs same-commit: ai.md Slice 14 + supersede marker on Slice 11, HANDOFF,
MyMistakes (CoreMessaging DQ + namespace-landmine recipe), TASK 17,
Controls/ViewModels/Services indexes.
IFfmpegLocator seam that resolves ffmpeg.exe (PATH -> cache -> pinned download),
plus the licensing compliance that makes a paid GA product defensible.
NOTE FOR USERS: this change shows NO difference in the app's behavior except a
new top-bar "About" button (opens THIRD-PARTY-NOTICES.txt). It is scaffolding
for the encoder/streaming work.
- Services/Encoder/: IFfmpegLocator + FfmpegLocator. Pin is BtbN lgpl-shared
autobuild-2026-08-09-13-03 (NOT gyan.dev/GPL or static: LGPLv2.1 §6 static
relink material avoided by dynamic linking); extracts ffmpeg.exe + libav*.dll
via a staging dir so a crash never leaves a partial cache
- THIRD-PARTY-NOTICES.txt: LGPL/BSD/MIT notices + source offer, copied to the
build output, surfaced by the About button; v1 gate = bundle full license
texts (TASK 4 requirement 9)
- ai.md "Licensing - do not violate" guardrails (never GPL/nonfree/static/latest-
tag, never link FFmpeg in, never drop notices); TASKS.md + Services/index.md
updated
- Tests: FfmpegLocatorTests - hermetic decision-ladder integration test + shared-
build DLL extraction + edge cases; docs updated (78 tests passing, 0 warnings)
Software compositor that renders a scene into the encoder's master VideoFrame,
mirroring the XAML preview minus editing chrome: backdrop -> background ->
elements (UniformToFill cover-crop, round clip, mirror, opacity, border) ->
branding flash.
NOTE FOR USERS: this change shows NO difference in the app's UI — it is pure
backend scaffolding laying the groundwork for live video capture/streaming.
The preview you see is unchanged.
- Services/Compositor/: SceneCompositor (Render(scene, frameFor resolver,
flashFrame, CompositorOptions)), CompositorOptions (source rect + output
size; 16:9 full master, vertical 607x1080 -> 1080x1920), StretchMath (pure
UniformToFill + bilinear), StaticPixelCache (asset bytes -> BGRA8 frame)
- Frame sources injected via Func<SceneElement, VideoFrame?> resolver, so the
compositor is pure, WPF-free, and hermetic to test (D3D11 upgrade behind the
same seam later)
- SceneElement.TryGetBorderColor public (shared hex parse), stale
MainViewModel comment fixed, pre-existing CS1998 in YouTubeAuthServiceTests
cleaned up
- Tests: SceneCompositorTests integration (full scene + vertical tier + flash)
+ StretchMath units, docs updated (72 tests passing, 0 warnings)
- Meter is a READ-ONLY realtime level display: fill = Math.Min(1, AudioLevel * MicVolume) (AudioLevel = live input from the future mixer, 0 with no input; MicVolume is gain on ambient noise). While the slider is dragged the bar previews the slider position (PreviewMouseLeftButtonDown/Up + LostMouseCapture -> SetVolumeAdjusting); on release it returns to the live level (bounces to 0 with no input). Clicking the meter does nothing.
- MicVolume drives MicMuted (read-only, muted <=> volume 0): sliding to 0 flips the speaker to the red slashed mute icon, sliding up from 0 clears it; speaker button runs volume to 0 or restores the prior level (_volumeBeforeMute, default 0.8) and flashes the meter to the restored position for ~300ms (BeginVolumeFlash/EndVolumeFlash DispatcherTimer, cancelled if the slider is grabbed).
- MIC label opens MicPickerDialog (WinRT audio-capture device enumeration, mirrors camera picker, no new packages); the chosen voice source name shows left-justified INSIDE the meter bar (fill at 75% opacity so text + ruler markings show through).
- New files: Services/IMicrophoneEnumerator, MicrophoneDeviceInfo, WinRtMicrophoneEnumerator; ViewModels/MicPickerViewModel; MicPickerDialog.
- Docs updated (ai.md, TASKS.md, Services/index.md, ViewModels/index.md); build 0 warnings, 65 tests passing
gramps