Two defects made the producer 17x slow (37s record -> 2.1s/127-frame file,
rawvideo stamps by arrival): FramePump slept the FULL interval after each
render (period = render+submit+interval) and SceneCompositor did per-pixel
float sampling + Math.Round blends over all 2.07M master pixels, scanning the
whole destination per overlay (258ms avg render vs 1.5ms submit).
Both solutions are established, not invented — researched before coding per
the derivative-work rule:
- deadline pacing: OBS libobs/media-io/video-io.c video_thread (nextTick +=
intervalTicks, sleep only the remainder, rebase on overrun, never burst)
- row blits: libyuv pattern (BSD-3, chromium.googlesource.com/libyuv/libyuv)
— 1:1 aligned identity fast path, per-pixel alpha branch, integer
fixed-point blend, overlay clipped to the intersection rect, skip the dead
black pre-fill when the backdrop covers
ONE integration test: Pump_Paces_To_The_Deadline_Compensating_Render_Cost
(lands after a fake-seam lesson: pacing fakes must await, not complete
synchronously, or the pump loop runs inline on StartAsync and hangs vstest).
Clean build 0 warnings; FramePumpTests 10/10, SceneCompositor/SceneGraph/
SocialBar/StretchMath 20/20. Docs same commit: ai.md pipeline section,
TASKS.md TASK 18 (webcam-in-output + rename modal verified from take 3),
MyMistakes recipe, HANDOFF rewritten. Take 4 pending on the user's machine.
- Modes: creator ruling 2026-09-01 — the VOD is the copy; dual encode degrades both
outputs on mediocre hardware ('we're not them'). ai.md 'cheap on NVENC' claim
retired; TASK 18 three-modes -> two; pills-become-radios noted as PENDING code.
- Design Principle gains 'we're not them' (hardware realism) as its fifth bullet.
- TASK 34 scope: countdown+notify live scheduling is the whole story — 'going live is
our schedule'. Scheduled playout discussed & DECLINED; premiere/upload + playout +
simultaneous-record-stream added to the closed out-of-product table.
- TASK 22: SYNC slider provenance restored — creator-requested (OBS delay-filter fix,
native). Placement question stays open; capability does not.
- MyMistakes: the provenance rule (a fact without its who/why becomes a future argument).
Docs only — zero code in this commit, per creator instruction.
Map corrections: ai.md encoded the webcam lookup bug verbatim (GetLatestFrame(WebcamId))
— code wins, line rewritten; frame-pipeline section gains the rawvideo arrival-stamping
lesson + stats log; TASK 18 status = running-app verification IN PROGRESS with take-3
pending on the pump starvation; state-model paragraph matches the new always-Start bar.
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.
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
The 2026-08-09 pin was a DAILY build; BtbN retention aged it out and the cold-cache
download 404'd on the creator's first native recording attempt (2026-09-01,
startup.log). Re-pinned to the MONTH-END build autobuild-2026-08-31-13-27
(N-126342, lgpl-shared win64 — 2-year retention; tag+variant recorded in TASKS.md
per the licensing rule). Verified alive: HEAD 200 + zip contents (bin/ffmpeg.exe,
bin/ffprobe.exe, 7 libav DLLs) match the name-agnostic extractor.
Also closes the wrap-gap: HttpRequestException escaped the locator untouched,
surfacing a raw 'Response status code... 404' from the frame pump; now wrapped in
IOException with the refresh-pin-or-install-ffmpeg message. FfmpegLocatorTests 7/7
(one updated, one added for the 404 case).
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.
All headless-testable TASK 21 decoder/mechanism slices shipped; the remaining UI
picker slice (AddMedia command + file dialog + Acquire/Release + Source.MediaIsLooping
-> IMediaFrameSource.Looping) is a GUI feature and is spec'd in HANDOFF for native
Windows build + verification. TASKS status + HANDOFF updated.
- 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.
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).
Root-cause note: the apparent remaining gap was a WIDGET GLOW EFFECT (the widget's own CSS glow pushed
out its perceived borders), not a code bug — the alpha-bbox already hugged the glow halo. Verified
perfect with a second widget without the effect.
- 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.
- FindContentBounds scans the Bgra32 capture for the bounding box of non-transparent pixels
(background is injected transparent, so alpha = widget extent). Crop to that rect + Stretch=Fill
maps the widget flush under the selection box: full-canvas widgets fall through to the full frame
(identical to the confirmed-good image); floating widgets get tight-fitted with no dead space.
- Removes QueryContentBoundsAsync + the JS script entirely — the DOM-union attempt (a5b9952) broke
rendering by measuring an unsettled layout on NavigationCompleted; alpha measurement is immune.
- 3 new unit tests: tight box, no-alpha no-crop, full-alpha no-crop. 7/7 pass, 0 warnings.
The wrapper-excluded content-union crop measured an unsettled layout on NavigationCompleted
(async fonts/images, load animations) and produced a broken/zoomed sliver — the image was gone.
Restoring the exact confirmed-good pipeline; the bounding-box dead-space problem stays open and
will not be touched without explicit approval.
- scrollWidth/scrollHeight returns the whole 1920x1080 canvas for widgets whose body/background
spans it, so the crop kept massive transparent margins and the content floated in the Fill box.
- ContentBoundsScript now unions every visible element's getBoundingClientRect, excluding elements
that span >=98% of the viewport (bodies, full-canvas background layers); full-bleed widgets fall
back to the full rect. Crop taken AT the rect's top-left (l,t) — content pins to bitmap (0,0).
- Web Image explicitly Margin=0 + Left/Top alignment so the frame and widget coincide at the origin.
- Canvas-size render untouched.
- QueryContentBoundsAsync now returns a real JS object (not JSON.stringify — ExecuteScriptAsync
double-encodes strings, which silently killed the old crop) and measures the union of every
visible body element's getBoundingClientRect: the widget's actual rect, top-left offset included.
- CaptureFrame crops AT that offset (x,y) instead of from (0,0), so the widget anchors at origin
and the box is flush on right/bottom. Fill maps the frame flush under the box.
gramps