The creator couldn't add a webcam to Live (grayed app-wide) and nothing in the
app explained why. Ground truth from the live DB: one Webcam identity AND one
WebcamSceneConfig in the Chat scene — so the gray was the single-identity rule
working, but the reason was unobservable. This slice makes the webcam a
resource the app validates and locks, mirroring how OBS reserves its devices.
At startup we enumerate the OS once (ValidateWebcamResourceStartupAsync, fired
after LoadLayout, stored as WebcamStartupValidationTask for tests to await):
- 0 webcams -> app runs on, layer inactive, no alarm
- exactly 1 -> attempt CameraManager.AcquireAsync as an app-wide lock; on
failure show a persistent red alert at the bottom of the Layers panel
(WebcamLockAlert + Retry) that re-polls every 5s and clears itself the
moment the camera locks, or on any first real frame
- >=2 -> deliberately no auto-lock; camera selection belongs to the App
Settings dialog (gear) — next slice
CameraManager.IsRunning(deviceId) tells the pass a session already exists
(started OR still starting) so loaded identity configs count as the lock and
the pass never double-acquires. Test seams mirror LayoutPathOverride:
CameraEnumeratorOverride / CameraFrameSourceFactoryOverride so the startup
probe never touches real hardware under test.
Good Dog test: WebcamStartupResourceTests x3 — single-cam locked + app runs on,
zero-cams no-alarm/no-lock, lock-fails -> red alert -> Retry -> clears. Full
suite 304/304, build 0 warnings, scope-check passed.
Docs in-commit: TASKS Open items + ai.md Webcam section + HANDOFF rewrite.
Also corrects the record: 'NVIDIA Broadcast opens the webcam exclusively' was a
suspect-list claim (CameraConflictProbe reads process names only, no handles)
— not restated as fact.
Take two (2026-09-01) three confirmed defects, all from creator feedback + the
new resolver logging:
1. NO WEBCAM IN OUTPUT: WebcamSceneConfig.WebcamId carries the identity GUID;
CameraManager keys sessions by DEVICE id — GetLatestFrame(guid) returned null
forever, the compositor silently dropped the layer while the preview (bitmap
path) looked fine. The resolver logging added in 8dcaee0 caught it red-handed.
DeviceKeyForWebcam maps identity->device through the _webcam singleton (identity
mismatch / unknown ids pass through). Test: WebcamOutputKeyTests.
2. START BUTTON VANISHED AFTER STOP: my pills-clear ruling met the old
ShowPrimaryStartButton gate (needed IsConnected or a lit REC pill) — signed-out,
pills-off = blank top bar, no session reachable. Start is now ALWAYS the idle
face; unarmed Start records (local needs no account — no dead-end no-op); the
Sign In button folds into Start's context menu ('Sign in to YouTube', shown while
disconnected) with a dedicated SignInCommand. SessionTeardownTests extended:
stopped session must leave a reachable Start.
3. TOP BAR ORDER (creator spec): [sign light] REC [pill] [sign light] ON-AIR [pill]
— each reality lamp now sits in front of its own intent switch (was: two pills,
then two orphaned dots). Sign labels keep the shared StatusSignText style.
Tests: WebcamOutputKey, SessionTeardown, FramePump, WebcamMenuGate, GlobalHotkey,
BroadcastPullOut — 14/14 across the six classes, clean build 0 warnings.
First real recording (2026-09-01): ffmpeg died at ~0.9s mid-session with ZERO log
lines while the pump fed a corpse for 9 more seconds. Three blind spots closed:
- OnStderrLine discarded everything non-progress: ffmpeg's actual words (startup
config, warnings, the reason it quit) now go to AppLog prefixed 'ffmpeg:' (400-char
cap so a \r-choked blob can't flood).
- Unexpected exit only fired ProcessFailed when code != 0 — a CLEAN exit vanished
silently. Any exit we didn't request is now logged and fired, any code.
- ExitCode read raced StopAsync's Dispose (tonight's 'No process is associated'
line) — guarded.
- VM output resolver logs once/5s when a webcam element resolves to a null frame
(preview showed the cam, recording didn't — the layer skip was invisible).
FfmpegEncoderTests + FramePumpTests 21/21 against the new code, 0 warnings.
User launch (2026-09-01 19:07) NRE'd in MainViewModel ctor:
1. SceneGraph (TASK 31) was 'null!'-declared, assigned mid-ctor, but Scenes is touched
~120 lines earlier — field-initialized now.
2. LeftPanel extraction (c9fd1bd) moved StaticResource users (EyeButton/EyeIconStyle)
into a UserControl while the styles stayed window-scope — invisible at parse time;
moved to Themes/Controls.xaml (app scope, the existing rule). Full audit: these were
the only two offenders (grep of Controls/*.xaml StaticResource keys vs app dictionary).
3. RoundClipInteractionTests — the second 'known failure' the map never explained: it
was two stale-test layers (window.FindName across the new UserControl namescope +
VisualTreeHelper.HitTest, which returned the IsHitTestVisible=False WebViewHostPanel
overlay for EVERY point; UIElement.InputHitTest — the real input pipeline — shows the
corner IS grabbable in both Traditional and Round). Test fixed, no product bug.
Verified: clean rebuild 0 warnings; app boots (log shows full MainWindow loaded; user
clicked + closed, zero new exceptions; real DB Webcam row = the genuine C920, untouched);
RoundClip + 6 RealApp classes pass natively per-class.
Docs: ai.md known-failure note → 246/247 (audio only); TASK 31 verification paragraph
corrected ('cannot run headless' overstated — per-class Windows-host vstest runs them);
MyMistakes: InputHitTest-vs-VTH recipe + namescope/app-style + shared-log facts.
Spin-guard citations: WPF Visual Tree Overview (InputHitTest vs VisualTreeHelper hit
semantics) + XAML namescope docs, learn.microsoft.com.
- IMediaFrameSource gains bool Looping.
- MediaVideoSource ctor takes Func<IDecodeProcess> processFactory instead of a
single IDecodeProcess: a System.Diagnostics.Process can't be re-Start()ed, so
each loop pass creates a fresh decoder. Decode wrapped in do-while(Looping):
restart on natural EOF instead of raising Completed.
- Production wiring (MainViewModel media factory): passes the process factory
AND FfmpegFrameRateProbe -- closes the slice-2b gap where production had no
probe and therefore no pacing.
- Tests: loop test (single frame re-emits across passes, Completed only when
loop cleared); fakes updated for the new interface member. Media tests 12/12,
build 0 warnings.
Wiring Source.MediaIsLooping into the flag needs a manager-level per-path loop
provider -> lands with the UI-picker (acquisition) slice.
Derivative reference: looping media by restarting decode on EOF, standard in
playback/overlay tooling (OBS media source repeat).
Wire the MediaVideoSourceManager into the live pipeline (new partial
ViewModels/MainViewModel.Media.cs mirrors Webcam/Background partials):
readonly _mediaManager assigned in the core ctor (decode at 1920x1080 master,
dispatcher-coalesced preview), OnMediaPreviewBitmapChanged adopts the shared
bitmap onto every IsMediaSource with a matching MediaPath, a
Source { IsMediaSource, MediaPath } case in ResolveOutputFrame feeds
GetLatestFrame, and the manager is disposed on shutdown.
Source.DisplaySource now routes VideoImageSource for MediaSource (Source.cs),
so media previews/canvas show decoded video.
Compositor needs no change: BlitContent UniformToFill-scales any frame to the
element rect. Decoder/manager/seam derived-work mirrors ScreenCaptureManager
(citation in commit for slice-step-3).
Test (one unit for this change, mirroring the live-capture case):
Source_DisplaySource_IsVideoImageSource_WhenMediaSource. 14/14 media +
DisplaySource tests pass, build 0 warnings. Docs (TASKS/HANDOFF/ai.md) updated.
- Add ElementKind (Static/Dynamic) to SceneElement base; Source/WebcamSceneConfig classify
- Services/SceneGraph.cs: owns the Scenes collection (ViewModel's Scenes delegates to it),
the element mutation surface (Add/Insert/Remove/Move, each invalidating the bake), and the
queries that were scattered LINQ (GetBackground/GetWebcam/GetChatBoxes/GetSplitPoint/IsStatic)
- SceneCompositor: split-aware BakeStaticBase + CompositeLayers + Render(.., staticBase, split);
builds/caches the static base below the split point in source-rect space
- FramePump: optional SceneGraph -> optimized bake+composite path; falls back to full render
- MainViewModel: routes element mutations through the graph; invalidates the bake on static
layout/opacity/visibility/useDefaultBackground changes and after background heal/Ensure
- Integration test SceneGraphTests.BakedStaticBase_WithDynamicLayer_CompositesCorrectly
Derivative survey (mandated): tried before writing — OBS does per-source opacity/visibility
caching and static-scene baking; this mirrors OBS's 'cached static source' optimization.
3 documented defensive deviations from the spec (ChatOverlayLayer stays decoupled;
background helpers stay VM-static for direct testability; full facade peel deferred post-1.0)
in TASKS.md + ai.md. Scope check passed; clean build 0 warnings.
The first true decomposition of the 4105-line god-object, not another partial
shuffle. MainViewModel.Chat.cs 194 -> 44 lines of thin delegation; all chat
behavior now lives in a self-contained Services/ChatOverlayLayer.cs (199):
- Owns the message buffer (Messages), ChatBoxRenderer, fade + mock-preview
timers, per-source preview renders, and the live-output RenderFrame path.
- The VM keeps only the binding surface: ChatMessages delegates to
_chatLayer.Messages (so XAML ItemsSource + LeftPanel CollectionChanged hold),
CanAddYouTubeChat / ShowChatInactiveMessage stay computed on the VM
(OnPropertyChanged raised from VM setters + XAML-bound), and thin forwards.
- Scenes handed in as args (no Func seam), so the layer owns no scene graph.
An AI reading ChatOverlayLayer.cs now sees the entire chat feature in one
self-contained unit. Zero behavior change; build 0 warnings; 246 pass, only the
2 known failures. Docs: ViewModels/index.md tracker updated in same commit.
Core MainViewModel.cs 758 -> 495 lines. Moved the source add/remove/image
block (AddSource, NextSourceName, AddImage, BuildImageCandidates,
PickImageBytes, AddAsset, AddImageSource, AddReusedImage, RemoveElement) into a
new MainViewModel.Sources.cs partial, and WebView2 source hosting
(RegisterLoadedWebSources, InitWebView2, OnWebView2PreviewBitmapChanged) into a
new MainViewModel.Web.cs partial. Pruned now-dead usings from core.
Zero behavior change; build 0 warnings; 246 pass, only the 2 known failures.
Docs: ViewModels/index.md Phase 3 tracker updated in same commit.
MainViewModel.Overlays.cs (194 lines) takes the settings/bug/feature/about
panels + creator-hub links: panel state (IsSettingsOpen/IsBugOpen/IsFeatureOpen/
IsAboutOpen via SetPanel, IsLicensesOpen, IsAnyOverlayOpen, OverlayTitle),
ShowOverlay/ShowLicenses, bug/feature report fields + SubmitBug/SubmitFeature/
ComposeEmail/OpenUrl, the About-hub consts (ChannelUrl/MastodonUrl/CoffeeUrl/
PremiumUrl/IsPremiumAvailable), SupportEmail/AppVersionLabel, LicensesText, and
the overlay command declarations (OpenSettingsCommand..OpenLicensesCommand).
Core drops 940 -> 758 lines. Ctor command assignments and all other wiring stay
in core; SetPanel/ShowOverlay keep their cross-partial calls.
This completes Phase 1: MainViewModel.cs has been split into 10 functional
partials (1,890 -> 758 lines in core).
Zero behavior change; build 0 warnings; 246 pass, only the 2 known failures.
Docs: index.md Overlays row added, About-hub row re-pointed, tracker marked
Phase 1 complete in the same commit.
MainViewModel.Streaming.cs (787 lines) takes the full go-live/record flow
(StartSession/BeginRecordOnly/BeginGoLive/PrepareAndStartLiveAsync/StopStream,
record-file naming + rename-on-stop), health pipeline (FramePump.Handle +
poll, report-by-exception banner), session timer, REC/ON-AIR start/end UI,
the resolution quality dropdown over the 1920x1080 master, live window
visual tokens (UpdateLiveVisuals), record-folder commands, broadcast
pull-out (CurrentBroadcastId/BroadcastForm) and the stream-state setters
(StreamStatus/StreamVisibility) + their fields. Core drops 1890 -> 1119
lines. Cross-partial references (IsConnected, IsEditMode, BrandFlash*,
_audioMixer, ctor wiring) are safe on one partial class.
Zero behavior change; build 0 warnings; 246 pass, only the 2 known
pre-existing failures (audio-mix gain + round-clip grab). Docs: index.md
Streaming row added + core row trimmed in the same commit.
MainViewModel.Socials.cs: social-bar state (_socials/_socialBarFrame/
_socialValidator), bar props (HasSocials/SocialBarVisible/SocialBarDotBrush/
SocialBarGlowBrush/Socials/SocialBarTop), OpenSocialDialog + NotifySocialsChanged
+ RenderSocialBarFrame (SocialBarRenderer), fediverse heal
(HealFediverseSoftwareAsync/HealFediverseSoftwareInBackground),
SetSocialBarPosition/ToggleSocialBarPosition, OpenSocialDialogCommand.
BarOnBrush/BarOffBrush/CreateBrush stay in core (shared tokens used by
Audio/Trax partials); core keeps ctor command assignment, LoadLayout,
SaveLayoutNow, and the compositor socialBar seam.
Docs: index.md restructured — each landed partial (Account..Trax) now owns its
own table row, the core row shrinks to only what remains in MainViewModel.cs,
and the split tracker is a compact code<->commit map.
Verify: 0 warnings, 246 passed, 2 known failures only.
Pure member movement into MainViewModel.License.cs (zero behavior change):
Polar license state (LicenseKey/LicenseMessage/IsLicenseValidating/
IsLicenseEntryOpen/IsHubVisible/IsPremium + OfflineGracePeriod),
ValidateLicenseAtStartupAsync, ActivateLicenseAsync. docs in same commit:
ViewModels/index.md split table (License ✔).
Pure member movement into MainViewModel.Account.cs (zero behavior change):
session restore (LoadSavedSessionAsync), sign-in/out/change (SignInAsync,
SignOutYouTubeAsync, ChangeAccountAsync), IsConnected + account avatar/name +
AccountStatusLightToolTip. Partial carries its own usings (ytLive.Services for
the INotificationService default interface methods). docs in same commit:
ViewModels/index.md split table + tagging convention.
Zero behavior change: \`public class\` -> \`public partial class\`. Each functional area
(Scenes, Background, Webcam, Audio, Trax, Socials, Streaming, Chat, Overlays,
Account, License) will move to its own file next, one commit per partial — each
a roll-back point. Docs updated in the same commit: ViewModels/index.md (split
map), ai.md (architecture table), HANDOFF.md (state). verify.sh: build 0 warnings,
only the 2 known pre-existing test failures.
Encoder dual-output: StreamEnabled/RecordEnabled/RecordPath options; per-output
ffmpeg block (stream ->flv, record ->mp4); throw unless at least one output.
RecordingFile: auto-name ty-<yyyymmdd>-<start hhmm>-0000.mp4, rename-on-stop to
ty-...-<len hhmmss>.mp4 with numeric-suffix on collision. LayoutStore persists
record folder. MainViewModel: REC/ON-AIR pills, status light, single Start<->End
button (replaces Start/Stop variants), StopStream no longer signs out, explicit
session timer. About overlay widened. Sign In label + spacing before Start.
Tests: 244 passed / 246 (2 pre-existing: AudioPipeline gains-mute, RoundClip).
Build 0 warnings. Scope check clean.
Memory-map correction (derived-solution rule, 2026-08-29): image-shrink recipe was
never recorded when first done, so it was re-derived. Added Derived-solution/recipes
rule to AGENTS.md; MyMistakes.md now a permanent recipes registry (records the
verified WPF-imaging shrink recipe); schema.md rows MyMistakes as registry; ai.md
points to the rule. README hero image replaced: 3.2MB screenshot -> 1400x794 ->
188KB docs/ytLlive-preview.jpg (JPEG q82).
- FindContentBounds already trimmed the bitmap; the grid/box still rendered at the uncropped user
size, so Fill stretched the tight widget into a bigger frame = dead-between-content-and-border.
- ContentCanvasSize maps the crop rect to canvas units (1920/pixW per axis, DPI-correct) and the
preview event now carries (bitmap, canvasW, canvasH).
- OnWebView2PreviewBitmapChanged sets the element Width/Height to that size; the grid and the
SelectionOverlay (both bound to the element's Width/Height) now equal the widget exactly.
- IsPreviewDragging (set in MainWindow drag/resize) suppresses auto-fit mid-gesture.
- Tests 10/10 (alpha bounds, canvas-size mapping incl. DPI, control size); 0 warnings.
Bundle exception (2026-08-27): this lands prior-session work plus today's
transparency fix as one commit per creator instruction.
WebView2Manager (new): off-screen WebView2 control parked at -5000/-5000 in
the window's visual tree, captures via CapturePreviewAsync every 100 ms into
a BGRA8 VideoFrame. Source Width/Height sync to the control via
PropertyChanged. JS transparent-background injection runs on every
NavigationStarting/NavigationCompleted so the page's own CSS does not paint
white over the capture.
Transparency fix: DefaultBackgroundColor = System.Drawing.Color.Transparent
set on the WPF control before EnsureCoreWebView2Async. The WPF SDK doc says
the value is forwarded to the controller on init; the IDL (ICoreWebView2-
Controller2) confirms alpha=0 makes the capture alpha-preserving. The
prior-session 'CoreWebView2.BackgroundColor' path was the wrong property
name and has been replaced.
LayoutStore: WebUri column added (idempotent ALTER TABLE) and round-tripped
on save/load (schema v11).
MainViewModel: WebView2Manager constructed on Loaded; loaded web sources
re-registered; Source.WebUri PropertyChanged forwards to manager.
MainWindow: off-screen host Canvas added to visual tree.
Tests: 3 scale-sync + WebView2_DefaultBackgroundColor_Is_Transparent +
LayoutStorePersistenceTests.WebSource_WebUri_Persists. 234/236 pass
(2 pre-existing failures unchanged).
Scale bug (DPI/physical-pixel mismatch) still open.
- Source.ShowDesktop bool persisted in DB (schema migration + LayoutStore)
- ClearBackdropCaptureAsync clears CaptureKey + VideoImageSource for static fallback
- Top bar: red/green/pulsing status light, avatar via BitmapImage, Log In button
- ShowStartStream now requires IsConnected
- RunMockChatPreviewAsync: simple async loop, ChatPreviewEnabled property on Source
- EnsureDefaultBackdrop called on every scene switch, seeds all 5 scenes
- SeedEndingBackdrop replaces existing, SeedChatBackdrop added
- SceneCatalog: Chat scene display name corrected (layer = 'YouTube Chat')
- Left panel spacing consistency, context menu reordered
- Border animation rendering via code-behind Storyboard approach
- 3 new backdrop assets (ending-backdrop.jpg, chat-backdrop.jpg, live-backdrop.jpg)
- Build 0 warnings, 178 tests passing
SeedBrbBackdrop() now updates the AssetId on an existing Background
source instead of bailing when one already exists. This ensures the
new brb-backdrop.jpg replaces any old image already in the DB.
gramps