The creator-declared known failure (Mix_HonorsProviderGains) and AudioPipelineTests'
standalone hang shared ONE root cause, born in TASK 22: AudioMixer.FillAndMix
dereferenced _delayedMix (declared float[]? , never assigned) as delayed.Length —
every live-mix tick NRE'd before the pipe write, so NO audio ever reached the wire
(tests starved -> hung/fail; app -> swallowed catch logged only ex.Message, 10ms
flood). Now: ctor-allocated + null-check, catch logs WITH stack via AppLog and is
throttled 5s, and a cancelled token breaks out before logging.
Bonus contract fix: AudioGainProvider.LoopbackGain returned unity on a disproven
premise ('loopback scales with endpoint volume'). The creator's tonight observation —
volume at 20%, meter pegged — proves the WASAPI tap is pre-endpoint-volume, so the
mixer must multiply by GameAudioVolume for stream honesty (this is what ai.md always
specified; the 'failing' test encoded the same and was RIGHT).
AudioPipelineTests: 25/25 in 26ms, standalone, no hang. Known-failure count: ZERO.
ai.md tests paragraph rewritten (no more suite-total claims, both ex-'knowns'
explained); TASK 22 regression recorded; MyMistakes: the known-failure-label rules.
Creator ruling 2026-09-01 (stuck REC pill after the failed first recording):
- StopStream clears RecordPillOn + OnAirPillOn — intent resets with reality.
- OnFramePumpFailed: dispatcher-marshalled FULL rollback via StopStream (was:
toast + Error-status only when live — record-only sessions zombied with
IsRecording=true over a dead encoder; the 20:34 attempt proved it). Toast copy
says 'Recording stopped' vs 'stream pipeline stopped'.
- Same zombie class in the three go-live prep failure branches: StreamStatus.Error
limbo replaced by StopStream() (audio loop + recording + pills unwind; a created
broadcast still gets the close-out).
- AudioMixer.StopLive made explicitly idempotent (Stop() twice, rollback paths that
never reached StartLive).
- Seams: OnFramePumpFailed + IsRecording setter internal (InternalsVisibleTo; test
pattern mirrors LayoutPathOverride).
ONE integration test: SessionTeardownTests (real window + temp DB: pump death with
lit pill -> no zombie, no End button, Offline). AudioPipelineTests confirmed to hang
STANDALONE (pre-existing, the declared-known audio class) — ai.md test-count
paragraph corrected to stop claiming a suite total that cannot currently be measured.
The specced 'End stream -> transition(complete)' call never existed: stopping relied
entirely on enableAutoStop (viewers sat on a frozen stream-offline for ~a minute, VOD
finalized late). Found during the 2026-09-01 recording-verification pass while the
creator asked 'if there's proper close-out info yt needs, we'll provide it?'
EndBroadcastAsync POSTs liveBroadcasts/transition?broadcastStatus=complete&id=..&part=status,
called after the pump stops (RTMP EOF first) and only when a live session had a broadcast —
record-only stops stay offline. invalidTransition/410 (autoStop already ended it) is logged
and returned as an error string, never thrown: a stop must never fail over close-out.
ONE integration test (URL shape + never-throws on 403). ai.md/TASKS.md design lines marked
SHIPPED with the map-lie note.
Ref: https://developers.google.com/youtube/v3/live/docs/liveBroadcasts/transition
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).
- MediaVideoSource takes optional IFrameRateProbe? + Func<TimeSpan,CancellationToken,Task>? delay
seams (default Task.Delay); probes FPS once in RunAsync, delays by 1/fps after each
emitted frame. No probe/unknown fps -> no pacing (ffmpeg pipe backpressure throttles).
- Test: MediaVideoSource_PacesFramesByProbedFps (fake probe returns 1000fps + recording
delay; one delay per frame ~= 1ms). Media tests 5/5, build 0 warnings.
Derivative reference: per-frame delay pacing of decoded output, standard in media playback.
- FfmpegFrameRateParser (pure): prefers avg_frame_rate= then r_frame_rate=,
rational N/N/M, unknown/0 -> null.
- IFrameRateProbe + FfmpegFrameRateProbe: derives sibling ffprobe.exe from the
located ffmpeg dir, reuses the IDecodeProcess seam for the ffprobe subprocess
text; null if ffprobe absent.
- FfmpegLocator now also extracts ffprobe.exe (ProbeFileName) from the pinned
archive, conditional so old caches without it degrade to no pacing.
- Tests: 6 pure parser units + 1 probe integration via fake locator/process;
FfmpegLocatorTests still green. 15/15, 0 warnings.
Pacing (probe->delay) is slice 2b. Derivative reference: standard ffprobe
avg_frame_rate probing used across OBS/media tooling.
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.
Adds the codec-agnostic decoder half of the media source. Spawns ffmpeg
with -f rawvideo -pix_fmt bgra (reusing the already-shipped ffmpeg via
IFfmpegLocator) and drains the raw BGRA stdout pipe into VideoFrames.
- Services/RawVideoFrameReader.cs: pure rawvideo BGRA stream -> frames
(partial reads kept across Feed; no ffmpeg needed to test)
- Services/IDecodeProcess.cs + FfmpegDecodeProcess.cs: binary-stdout
subprocess seam, mirror of the encoder's IEncoderProcess
- Services/MediaVideoSource.cs: owns the decode, raises FrameReady/Completed
- MediaVideoSourceTests: 3 pure reader + 1 integration (fake decode
process through the real source loop, frames in order)
Reference (external scan): ffmpeg rawvideo pipe decode is the canonical
codec-agnostic frame feeds pattern (ffmpeg docs -f rawvideo; how OBS/media
pipelines push frames to a compositor). Verified: 4/4 tests, build 0 warnings.
Native-FPS pacing + resolver/compositor wiring are the next slice.
- 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.
ai.md: Key patterns gains the 'true decomposition beats partial-shuffling'
rule + the glue-vs-component diagnostic (count OnPropertyChanged/SetProperty;
extract only zero/low-glue cohesive state blobs like chat's; leave binding glue
over already-extracted services alone; line count is a guideline not a goal).
ViewModels table row notes Chat.cs is now a thin facade over ChatOverlayLayer.
HANDOFF: everything through Commit G is pushed (origin/main=85893ea); the
remaining big decomposition is the scene-graph segment, flagged as design-needed
(not an unsupervised peel).
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).
Project lesson cited (the 2026-08 web-box saga, 9 commits): browser sources are fixed canvases
per OBS convention — the 'gap' was a widget CSS glow, not a bug.
- 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
gramps