LlamaCasty/TASKS.md

# ytLlive — Task List

> Task queue and authoritative research. Memory-map conventions: [`schema.md`](schema.md);
> architecture/decisions: [`ai.md`](ai.md). Update statuses here whenever a task moves.

> **Checklist markers** — every task's Status list uses the same states:
> 1. ✅ — completed (green check)
> 2. 🔶 — in progress (amber diamond)
> 3. ☐ — not completed / pending (empty box)
> 4. ❌ — exception (blocked, known-issue, or deliberately excluded from this build)

## YouTube Live API — research facts (authoritative, v3 build)

Lifecycle: `created → ready → [testing] → live → complete` (transitional `liveStarting` / `testStarting`).

1. **liveBroadcasts.insert** requires: `snippet.title`, `snippet.scheduledStartTime`, `status.privacyStatus`, `status.selfDeclaredMadeForKids` (COPPA).
2. **liveStreams.insert** requires: `snippet.title`, `cdn.frameRate`, `cdn.ingestionType`, `cdn.resolution`. **None of the four (except title) can ever change after creation** — changing them means delete + recreate the stream. This is the hard constraint behind the quality grey-out.
3. **Title / description / privacy**: editable at any time, including while live (`liveBroadcasts.update`, part=`snippet,status`).
4. **contentDetails** (DVR, recordFromStart, monitorStream, embed, latency): editable only in `created` / `ready`.
5. **Transition to live** only allowed when the bound stream's `status.streamStatus == active`.

### Two features that reshape the design

1. **enableAutoStart / enableAutoStop** — instant one-click go-live, no transition call. With `enableAutoStart=true` we never call `transition(live)`: the broadcast auto-goes-live the moment the encoder starts. Combined with `enableMonitorStream=false` (our preview pane replaces YouTube's monitor stream — the thing that forces a testing stage), the flow is **create → bind → Start Stream → encoder starts → YouTube brings it live**. No testing, no transition polling, no liveStarting stuck-state handling.
2. **`cdn.resolution=variable` / `cdn.frameRate=variable`** — free auto step-down. YouTube auto-detects what we send; since we ARE the encoder we can drop bitrate/resolution on the fly with zero API calls. Declaring an explicit resolution instead (e.g. 1080p) requires a new stream, which can't happen mid-broadcast. Variable is the enabler for the whole auto step-down feature.

### Compliance gotchas (maps perfectly to report-by-exception)

1. `liveStreams.status.healthStatus`: `good | ok | bad | noData` plus `configurationIssues[]` with `type` + `severity` (`info|warning|error`). Literally built for report-by-exception — poll it, render nothing on good/ok, surface a banner only on warning/error. No need to invent our own health logic.
2. Encoder must comply or YouTube flags it: keyframes ≤ 4s (`gopSizeLong`), closed GOP, H.264, audio AAC/MP3 @ 44.1/48kHz, mono/stereo only.
3. Error codes to handle: `errorStreamInactive`, `invalidTransition`, `redundantTransition`, `liveStreamDeletionNotAllowed`, `liveStreamModificationNotAllowed`, `liveBroadcastBindingNotAllowed`.

### Tips we should take advantage of

1. **Reusable streams** (`isReusable=true`): one stream per channel, cache its ingestion URL + stream name, reuse for every broadcast. No rebinding dance each go-live. This is exactly the manual-stream-key baseline.
2. **Backup ingestion address**: YouTube provides a simultaneous-push backup — future hardening, not v1.
3. **`recordFromStart` + `enableDvr` default true** → every live is auto-recorded and immediately replayable. Free VOD archive, matches the v0.2 recording goal.
4. **`latencyPreference`: `normal | low | ultraLow`** — for homelab streamers talking to chat, `low` (or `ultraLow`, capped at 1080p) is a real feature.
5. **Broadcast ID == Video ID** — one ID to track everything.

---

## TASK 1 — Initial Scaffold

**Goal:** Working C# / WPF project with MVVM architecture, dark-theme main window, and YouTube service stubs.

### Status: ✅ Done

1. ✅ Models: Scene, Source, StreamConfig, StreamHealth, YouTubeChannel, ChatMessage
2. ✅ Services: YouTubeAuthService (OAuth2), YouTubeStreamService (broadcast/health), YouTubeChatService (chat polling)
3. ✅ MainViewModel: scene management, stream controls, chat
4. ✅ MainWindow: scene/source panel, preview area, chat panel, status bar
5. ✅ Clean build, 0 warnings (WSL + Windows)

---

---

## TASK 2 — YouTube OAuth2 Authentication

**Goal:** Fully working Google OAuth2 flow — user clicks "YouTube", browser opens, authorization callback lands, channel info is stored.

### Status: ✅ Done

1. ✅ Two-state Start/End Stream button, go-live dialog (account + title/description/visibility), red top bar, pulsing LIVE badge + elapsed timer, preview glow, taskbar red dot
2. ✅ Real OAuth2 wiring — baked-in Google credentials (desktop client; loopback callback) + `YouTubeAuthService` complete: browser launch, `HttpListener` callback, token exchange, refresh, channel fetch
3. ✅ Token persistence via Windows DPAPI (`Helpers/TokenStore.cs` → `%APPDATA%\ytLlive\ytLlive.auth`), best-effort reload + proactive refresh at startup, saved after every exchange/refresh
4. ✅ Account sign-in/change surfaced in the GoLive dialog (saved account shown with "Change Account"; "Sign in to YouTube" when none; Start disabled until signed in)
5. ✅ **End Livestream signs out** — a graceful end completes the session: `StopStream()` calls `YouTubeAuthService.ClearSession()` + `TokenStore.Clear()` + `IsConnected = false`, so the next Start Stream dialog requires a fresh sign-in. A crash never runs End, so the DPAPI token survives and the creator stays signed in. Resume/reconnect after a midstream crash is deliberately deferred to TASK 3: the socket can't be resumed (it dies with the process), so "resume" = fast reconnect with a saved broadcast ID/stream key within YouTube's disconnect-grace window; too slow and `enableAutoStop` ends the broadcast
6. ✅ Tests in `ytLive.Tests` (xUnit, net8.0-windows): TokenStore DPAPI roundtrip/corrupt/missing/clear + mocked exchange channel-parse + refresh expiry bump + `ClearSession` — 7 passing

**Design constraint:** Sign-in must NEVER block core exploration. Users can build scenes, add sources, and audition the software without authenticating. But **going live requires authentication** — the "Start Stream" dialog is where the account sign-in lives, alongside all stream metadata.

**Two-state flow:** There is no separate "Connect" button. The top bar shows a single button — **Start Stream** when idle, **End Stream** when live. Clicking Start Stream opens one dialog that supplies everything: account (previously-saved account shown as default, with a Change Account action) + title/description/visibility.

**Live indicators (unmissable):** Top bar + window title bar flip red, a pulsing **● LIVE** badge with elapsed timer appears in the top bar, the preview area gets a red glow, and the taskbar icon shows a red overlay dot. Window title bar shows the stream title once validated.

### Requirements:

1. **Google Cloud OAuth credentials** — client ID + secret, **baked into `Helpers/OAuthCredentials.cs`** (desktop "Desktop app" OAuth client; loopback callback — no console redirect URI registration needed; creators never configure)
2. **Local HTTP listener** — `HttpListener` on `http://localhost:PORT/oauth2/callback` to catch the redirect
3. **Browser launch** — open the authorization URL in the default browser
4. **Token persistence** — store access/refresh tokens securely (Windows DPAPI), reload on startup
5. **UI state** — account shown in the Start Stream dialog; "Change Account" action triggers re-auth
6. **Go Live gated on auth** — Start Stream dialog requires sign-in to enable the Start button; scene building works without it

### Tests:

1. Mock token exchange response, verify channel info parsed
2. Verify token refresh triggers when near expiry
3. Verify credential load/save roundtrip

---

---

## TASK 3 — Capture Pipeline (Scenes/Sources)

**Goal:** Real video preview in the center panel — the minimal source set below, composited per scene.

### Status: 🔶 In progress

1. ✅ **Milestone 1 — webcam** — MediaCapture (WinRT SDK projection) with device enumeration, CPU-first frame source, refcounted `CameraManager`, picker dialog, clip shapes (Traditional + Round) + mirror, 480×270 default placement — schema v2
2. ✅ **Schema v3 (Ship Branch A)** — multi-scene webcam (singleton `Webcam` + per-scene `WebcamSceneConfig`), right-click border/context menu, static OBS-style borders, 50%-per-dimension webcam size cap, device-swap (`ReleaseAllAsync`) — 25 tests passing
3. ✅ **Schema v4** — round→rect restore persisted (`WebcamSceneConfig.RectWidth`/`RectHeight`) + one-time legacy-square 16:9 heal on load
4. ✅ **Screen backdrop (ship task #1, schema v5)** — live desktop/game capture as a permanent, non-deletable bottom layer (`Source.IsBackdrop`), auto-detecting the full-screen game at launch/focus (else the **primary display** — never assumed monitor 0) via `Win32FullScreenDetector` (now with `GetDisplays()`/`PrimaryMonitorIndex()` for the in-app display picker), content re-designated via the OS `GraphicsCapturePicker` ("Change Capture…") or the in-app "Capture Display" submenu, refcounted/shared capture sessions in `ScreenCaptureManager` mirroring `CameraManager` — 45 tests passing
5. ✅ **Schema v6 — backdrop Live-only by policy** — `Scene.HasBackdrop`, enforced by scene name on every load (`EnforceBackdropPolicy`: Starting/BRB/Chat/Ending never carry one; the one-time v5→v6 backfill covers all four), the scene context-menu "Backdrop" checkbox is gone (policy owns the flag), preview watermark hides when the backdrop renders, capture changed to `WindowsRuntimeMarshal.TryGetDataUnsafe` (the CsWinRT-safe frame-read) + downscale to the 1920×1080 master + 5s-throttled error logging (was flooding `startup.log` with 5 MB of cast errors and burning CPU), round webcam no longer re-rasterizes an `ImageBrush` every frame (Image + EllipseGeometry clip) — the live-mode stutter fix
6. ✅ **The five-scene catalog (`SceneCatalog`)** — Starting/Live/BRB/Chat/Ending is the product — work with less, never more; the (+) button only shows when a canonical scene is missing and re-adds it (its menu lists only the missing ones) — 62 tests passing
7. ✅ **Webcam-after-session-start fix** — a webcam added to a scene after the camera was already running (e.g. Chat) previously rendered a transparent container — `CameraManager.GetPreviewBitmap` + propagation in `AddWebcamToActiveSceneAsync`/`ReacquireWebcam` now hands the running shared frames to any newly added `WebcamSceneConfig` — 65 tests passing
8. ✅ **Chat scene webcam size cap** — raised from 50%-per-dimension (960×540) to half the screen AREA (~1358×764 @16:9, `MaxWebcamWidthFor`/`MaxWebcamHeightFor` keyed by canonical name) so the viewer sees the creator better
9. ✅ **"Add Webcam" always opens the camera picker** — deleting one scene's webcam then re-adding used to resurrect the old camera when another scene still used it — `SwapWebcamIdentityAsync` now swaps the app-wide identity if a different camera is chosen, same path as "Change Webcam…"
10. ✅ **Webcam resource validation + first-frame proof** — `MediaCaptureFrameSource` validates post-init (VideoDeviceId match, stream properties ≥1, `reader.StartAsync()` status read + throws on non-Success); subscribes `capture.Failed` + `CameraStreamStateChanged` → `SourceFailed` event on the seam; fallback ladder (VideoPreview → VideoRecord). `CameraManager.AcquireAsync` requires first-frame proof (4s timeout): returns true only after a real frame arrives — silent empty box impossible. `MainViewModel` subscribes `CameraFailed` → red `WebcamError` chip in preview + MessageBox names suspect apps (`CameraConflictProbe`). 19041 SDK projection gaps: `Exclusive`/`DeviceLost` not projected; `CameraStreamState.Failed` compared by `(int)2`. 81 tests passing
11. ✅ **Scenes/sources UI** — add/reorder/rename, image + background overlays with move/resize/opacity/reuse
12. ✅ **Audio UX shipped (UI)** — the bottom-bar footer is now two lines (dropped/duration moved under bitrate/fps), with the mic's sound meter + mute button + volume slider grouped CENTERED on the footer's top line, beneath the preview panel (meter: 288px, muted slate track with ruler graduations + muted yellow/red zone tints, green→yellow→red fill; mute = speaker icon → red do-not-symbol when muted, and the slider and speaker stay in sync (volume 0 ⇔ muted — sliding off flips the speaker to muted, sliding up from 0 clears it); mic volume defaults to 80%, muting zeroes the meter and restores the prior volume on unmute (which flashes the meter to the restored position ~300ms before it returns to the live level); the meter is a READ-ONLY realtime level display (fill = live level × volume — volume is a gain on ambient noise; while the slider is dragged the bar previews the slider position and bounces back to the live level on release, which is 0 with no input — clicking the meter does nothing), clicking the MIC label opens a microphone picker whose chosen source shows left-justified inside the meter bar (fill at 75% opacity so the name + ruler markings show through); slim dimensional slider — gradient track/fill, gloss-sphere thumb; the old flat pink 18px-filled one is gone), everything else on line 2 (bitrate/fps/dropped/duration/health left, quality + gear right) — the creator's only audio control, desktop/game audio is automatic (KISS rule). **Post-test follow-up (2026-08-13, game audio bar branch):** the **game audio bar** (desktop/game, a mirror of the mic bar: meter + mute + volume) is **overlaid at the bottom of the preview window** (bottom-center dark chip — monitoring UI only, never on the live output) and appears only while a **full-screen game is producing sound** in the preview (`IGameAudioDetector` seam + default `GameAudioDetector` polling `IFullScreenDetector` + the live loopback level, floor 0.5%, into a pure `GameAudioHysteresis`: SHOW after ~500ms of fullscreen+sound, HIDE ~1s after leaving fullscreen, **silence never hides an active bar**; the VM polls it on a 250ms `DispatcherTimer`); **capture now runs for the app's lifetime** (mixer started once at startup via `StartMicCaptureAsync`, disposed in `Shutdown` — not go-live) so the meters preview live; the **MIC label became a button with a status dot** (`Models/MicStatus`: green = connected via the source `Started` event, yellow = mic problem, red = no device); picking a mic takes effect immediately (`AudioMixer.RestartMic`, loopback keeps running); fixed a latent `?.Invoke(meter.Push(...))` short-circuit that skipped the meter update when nothing was subscribed. **Round 2 (2026-08-13):** the meters were dead on a flat scale (real speech/game RMS is ~0.01..0.1 linear) — the raw level is now mapped via `AudioLevelMeter.ToDisplay` (−60..0 dBFS spread across 0..1) so typical input reads ~1/3..2/3 of the bar at default volume. 169 tests passing, 0 warnings. **Round 3 (2026-08-13):** the mic bar gained a **mic mute icon** (a microphone glyph in the speaker's 16px style, red + slash when muted) between the meter and the speaker — both mutes adjacent with spacing between them, same `ToggleMicMuteCommand`; and the top-center LIVE badge became an **always-visible REC sign** — dark gray dot + dim "REC" offline, bright red (#e94560) + "REC" + elapsed while live, **darker red (#8f1f1f)** when live with a **private** stream (driven by the dialog's chosen visibility) — `RecDotBrush`/`RecTextBrush`/`RecDotOpacity`/`IsLivePrivate`, pulsing while live. **Queued:** task 22 (voice filters). Voice-filter note: the meter's `ToDisplay` input is the pre-filter mic level; when filters land they must apply BEFORE the meter/encoder mix
13. ✅ The connected YouTube account's avatar/name shows in the top bar next to Start Stream (`SyncConnectedAccount`); the scenes list is content-height now (no dead space before SOURCES)
14. ✅ **Social bar v2 (six-slot dialog, sign-in gate, real logos)** — global bar layer (never a Source, no sources-list row), content-sized, centered, GREEN glow when ON, top/bottom snap-drag (default BOTTOM, persisted `SocialBarPosition`; drag clamps to 0/1040, tie→bottom). Footer Social button gets a state dot (green=ON). Dialog "Social Media Site Promotion" (`SocialsDialog` + `ViewModels/SocialsDialogViewModel`, WPF-free + injected `ISocialValidator`/sign-in/sign-out fakes): ON/OFF bar switch (`SocialsConfig.BarEnabled`, schema v8), 6 fixed slots — row 1 always YouTube (signed-in → channel handle; signed-out → sign-in gate → OAuth; delete → confirm sign-out, mirrors `StopStream`), row 2 free, rows 3-6 lock icons on freemium (Premium seam: all six). Validation: `DetectService` (URL domain / fediverse `@user@domain` / bare→Website) → async `ISocialValidator` on confirm/Save; valid snaps to text + real service logo (bundled SVG path data via `LogoDataFor`, Simple Icons CC0 — initials badges gone); invalid → red do-not, stays editable, Save blocked. LCR justify dropped (`BarJustify` unread), per-scene toggle dropped (`Scene.HasSocialBar` back-compat). **Post-test fixes (2026-08-12):** footer label "Socials" (not "Social"); fediverse `@user@domain` validates — the full handle is the identity end-to-end (`DetectService`/`CanonicalUrlFor`/`HttpSocialValidator` build `https://domain/@user`, no domain loss); **Cancel is a hard stop** — `ISocialValidator.LookupAsync` takes a `CancellationToken`, dialog VM owns a CTS, Cancel/X/Save abort in-flight lookups (HTTP request killed, canceled continuations never touch slot state), and `ConfirmEdit` skips re-submitting identical text (LostFocus on dismiss never re-fires a lookup). `HttpSocialValidator` now has real tests (fake `HttpMessageHandler`). 105 tests passing. **Post-test fixes (2026-08-12, round 2):** fediverse `@user@domain` no longer shows a generic chain — it resolves to the instance's actual software via nodeinfo (`/.well-known/nodeinfo` → `software.name`; `SocialService.Fediverse` enum member + `SocialEntry.FediverseSoftware` persisted in a new `SocialEntry.Software` column, schema migration by column-presence) and renders that software's bundled logo (`LogoDataForFediverse`: mastodon/peertube/pixelfed/misskey/lemmy/pleroma/firefish, generic fediverse honeycomb fallback). Dialog row-2 edit/trash icons were too dark — `IconButton` style gains `Foreground=#d0d0d0`; trash overrides `#e94560` (app red). 112 tests passing. **Post-test fixes (2026-08-12, round 3):** a fediverse handle whose identity domain is itself a redirect (e.g. YunoHost default-app subdomains — `@user@llamachile.tube` where the mastodon instance lives at `mastodon.llamachile.tube`) now still resolves its software: nodeinfo on the identity domain is SSO-blocked, so `HttpSocialValidator` follows the bare root `https://domain/` 302 to the real instance host and re-runs the nodeinfo lookup there.
15. ☐ **Window capture** — absorbed into the Screen picker (no separate source type); dedicated window-as-source work is pending
16. ☐ **Scene compositing** — the D3DImage/MediaElement preview compositor (this task's requirement 5; the output compositor ships as TASK 4 ship step 1)
17. ☐ **Text source** — live text ("Starting soon", "Back in 5", handle, callout)
18. ✅ **Chat box** — YouTube live chat rendered *on* the stream so viewers read along in-video — `ChatBoxRenderer` (WPF FormattedText → VideoFrame), configurable font size/color/badges/timestamps/max-messages via Elements panel, schema v10, persisted across save/load
19. ❌ **Background removal (milestone 2)** — ONNX Runtime + DirectML, MediaPipe Selfie Segmentation — deliberately NOT in this build
20. ☐ **Alerts** — Super Chat / membership / subscribe pop-ins; build after the six; **the one paid feature** (see Monetization in `ai.md`)
21. ✅ **Show Desktop toggle** — `Source.ShowDesktop` bool persisted in DB (schema migration + LayoutStore read/write). When checked, primary monitor captures regardless of fullscreen game state. Toggling off falls back to running game or releases to static placeholder. `ClearBackdropCaptureAsync` clears `CaptureKey` + `VideoImageSource` so static fallback renders. Toggle on Live backdrop context menu (IsCheckable MenuItem).
22. ✅ **Top bar — status light + avatar + Log In button** — red/green/pulsing ellipse (disconnected/connected/live). Avatar border visible only when connected, loads via `BitmapImage` code-behind. "Log In" button visible when disconnected, calls `StartStreamCommand` → GoLiveWindow. `ShowStartStream` now requires `IsConnected`.
23. ✅ **Chat preview — one-at-a-time mock messages** — `RunMockChatPreviewAsync`: simple async loop, displays `MockChatMessages[n]` via `Take(n+1)`, 1000ms between messages, wraps at end. `ChatPreviewEnabled` property on Source (default true). Stops on real messages, restarts on fade timer clear.
24. ✅ **All backdrops seeded + EnsureDefaultBackdrop** — Live, Chat, Ending backdrops added (ending-backdrop.jpg replaced). `EnsureDefaultBackdrop()` called on every scene switch. `SeedEndingBackdrop` replaces existing (not skip-if-exists). Chat scene no longer skipped.
25. ✅ **SceneCatalog fix** — Chat scene display name corrected to "Chat" (was "YouTube Chat" — that name belongs to the layer/SourceType.ChatBox, not the scene).
26. ✅ **Left panel spacing + context menu reorder** — HR margins matched, Row 4 changed from `*` to `Auto`. Context menu reordered: Border Thickness first, then Opacity, Color, Effect.
21. ✅ **Logo + richer in-app About (2026-08-13, queued → 2026-08-14 SHIPPED)** — the ytLlive wordmark in the top bar opens the About overlay (already wired); the About overlay is now the **creator hub**: the real logo (the "llama fortnite superman logo" from the creator's vault, copied to `Assets/llama-logo.png` — the creator's own art, no third-party license), plus **creator-hub links** — llama chile shop on YouTube (`MainViewModel.ChannelUrl`), Mastodon (`https://mastodon.llamachile.tube/@gramps`), **Buy me a coffee** (`https://buymeacoffee.com/llamachiley` — live), and **Unlock Premium** (greyed "coming soon" — the **billing** product URL is a tabled seam, `PremiumUrl`, until TASK 10 picks the subscription provider). A **Licenses & legal** button flips the About overlay to an in-app scrolling panel that loads the full `THIRD-PARTY-NOTICES.txt` text (`MainViewModel.ShowLicenses` reads the shipped file from the executable directory on first open; graceful "not found" fallback — **never the OS viewer, everything stays in-app**); "← Back to About" returns. The About overlay is also the in-app home of the notices — the top-bar About button that opened the file in the OS viewer was removed on 2026-08-13 for exactly this reason. Integration test (Good Dog Rule — ONE): `AboutHubTests.About_Opens_InApp_Licensing_Loads_Shipped_Notices` drives the real window + VM, asserting the hub opens, the link URLs are real, the licensing panel loads the shipped notices text (contains "Third-Party Notices" + "LGPL"), and back returns to the hub. 174 tests passing, 0 warnings
22. ✅ **Voice filters on the mic channel (2026-08-13 queued → SHIPPED 2026-08-14 inside TASK 9, the audio milestone)** — the standard four applied to the sound input path (before the meter/encoder mix): **bass boost, treble, noise suppression, compressor** (set decided with the creator 2026-08-13). Noise suppression = a **pure-C# noise gate** (creator chose over RNNoise / a second ffmpeg `afftdn` pipe, 2026-08-14 — KISS). Always-on — no UI knobs; the mic stays the creator's single audio control
27. ✅ **Webcam row gates on the app-wide identity (2026-08-24, TASK 26)** — the (+) menu's Webcam item greys out whenever a webcam exists **anywhere** (`CanAddWebcam` = `StagedScene != null && _webcam == null`; renamed from `CanAddWebcamToStagedScene` whose per-scene rule let a second picker run from a scene lacking the config), raised at both `_webcam` mutation sites (create / last-config removal) + scene staging + elements change. Creator's visual pass found it: minis/no-capture-rows/capture-controls all good. ONE integration test `WebcamMenuGateTests.CanAddWebcam_Gates_On_The_AppWide_Webcam_Identity` (real window + temp DB seeded with a webcam in Starting; asserts greyed while Live staged, re-enabled after `RemoveSourceCommand` clears the last config + the `Webcam` DB row). Stale map fixed in the same commit: ai.md's "empty-canvas right-click Show Webcam" claim dropped — that XAML never shipped (`ShowWebcamCommand`/`CanShowWebcamInStagedScene` are wired but unbound dead code, audit item). 224 tests (223 pass; the pre-existing AudioPipelineTests failure is unrelated)
28. ✅ **YouTube Chat layer: one-per-layout gate + legacy label heal (2026-08-24, TASK 27)** — same rule as TASK 26 applied to the chat layer: the (+) menu's YouTube Chat item greys out while any scene carries a ChatBox source (`CanAddYouTubeChat`, raised on staging + elements change; `AddSource` refuses a second), tooltip "One chat layer at a time — it's already in your stream". Plus the creator's label fix: layers added by commit `65641d8` were named "Chat"; LoadLayout now heals exactly that un-renamed default to "YouTube Chat" so the Layers row matches the (+) picklist (creator renames untouched, idempotent). ONE integration test `ChatLayerGateTests.LegacyChatName_Heals_And_CanAddYouTubeChat_Gates_On_The_Existing_Layer` (real window + temp DB with a legacy "Chat" row: healed on load + persisted on save, greyed cross-scene and in-scene, re-enabled after remove). 225 tests (224 pass; pre-existing AudioPipelineTests failure unrelated)
29. ✅ **Broadcast metadata pull-out + launch geometry (2026-08-24)** — creator ask: "a tab-pullout on the right side of the preview pane — white tab, YouTube-red label reading 'Text' — opening a form with all settable liveBroadcast fields; fields that can't be filled before launch greyed out; saving/updating remote content; field data saved and pre-loaded on app run". Shipped as specified with one correction: the API is the inverse of "more fields once live" for contentDetails (those lock in created/ready) — the pull-out carries the always-editable snippet/status set: Title, Description, Tags (csv), Visibility (private/unlisted/public), Made-for-Kids, plus read-only Scheduled Start. **Always visible** (creator revised same day from Live-only gating). White 30px tab, rotated red "Text", right edge vertically centered; click slides a dark 320px drawer left over the preview (200ms CubicEase). Every edit persists to Settings keys (`Broadcast.*`) immediately; **Update Broadcast** button calls the new `YouTubeStreamService.UpdateBroadcast` (PUT `liveBroadcasts?part=snippet,status`, echoes scheduledStartTime because update replaces the whole snippet part). Go Live prefills from the form and captures what was inserted (`CaptureGoLive`). The old un-persisted Default Stream Title/Description fields came OFF the App Settings overlay (replaced by the form); `DefaultStreamTitle/Description` VM properties deleted. **Launch geometry** (same unit): default 1920×1040, MinWidth 1366, MinHeight 768; `WindowStartupLocation=Manual` + window size/position persisted on close via `RestoreBounds` (maximized-safe), restored in ctor clamped to minimums and the primary work area (disconnected-secondary fallback). ONE integration test `BroadcastPullOutTests.Metadata_Persists_WindowRestores_Clamped_And_UpdatePatchesRemote`. 228 tests (227 pass; pre-existing AudioPipelineTests failure unrelated)

### The Minimal Source Set (design decision — do not expand casually)

ytLlive is YouTube-only and 90% of users are casual. OBS's long source list is off-putting; we ship
the hot few and nothing esoteric. If a user needs more, they've graduated to OBS.

1. **Webcam** — the face cam. Non-negotiable.
2. **Screen** — the main event (game, slides, browser). One source; a picker chooses a monitor *or* a
   window. (Window capture is absorbed here — no separate source type.)
3. **Background** — a full-canvas backdrop image. Fills the whole scene automatically, zero fiddling.
   Kept separate from Image on purpose: same pixels, but this one needs no positioning.
4. **Image** — a floating graphic/logo overlay (watermark, badge, corner branding). Free-positioned.
5. **Text** — live text ("Starting soon", "Back in 5", handle, callout). Casual streamers live on this.
6. **Chat box** — YouTube live chat rendered *on* the stream so viewers read along in-video. YT-native.
7. **Alerts** — Super Chat / membership / subscribe pop-ins. The dopamine source. **The one big lift**
   (Super Chat event streaming + on-stream rendering/animation); build after the six. **Also the one
   paid feature** — see Monetization in `ai.md`.

Deliberately NOT supported: game capture, browser source, media playlist, VLC, color-key voodoo, MIDI.

### Source memory model (design decision)

1. A scene has resources. Resources can be shared across scenes.
2. A resource exists exactly once in memory, no matter how many scenes use it (a logo in five
   scenes = one loaded bitmap).
3. Every resource carries a **catalog of scenes**: one usage entry per scene it appears in, each
   entry dictating that scene's use — placement (X/Y/Width/Height), opacity, z-order, enabled,
   scale mode, crop.
4. Usages are named `{resourceName}.{sceneName}` — whatever the user named the resource, dot, the
   scene name: `logo.starting`, `logo.live`, `myPic.brb`. Not a hardcoded "logo".
5. A webcam in two scenes = one capture session, two catalog entries.
6. Refcount by catalog size: the last usage removed → the resource is disposed and evicted.
7. The resource (not a per-scene node) owns everything `IDisposable`.

### Scene transitions (design decision)

Scene switching while live must never stutter. Supported types, most → least economical:

1. **Cut** — instant switch. The default. Zero cost.
2. **Fade** — short crossfade (~300ms).
3. **Move** — a simple, economical move transition, done to perfection and memory-efficient. The
   smart streamer's bread and butter.
4. **Custom (media) transitions** — require media elements (video/stinger playback during the
   transition). Heavier, but creators pay for these, so we support them. Their media follows the
   same resource memory model: loaded once, catalogued by scene.

Preview shows the transition too (WYSIWYG). No wipes/slides/LUTs beyond the four above.

### Requirements:

1. **Screen** — Windows.Graphics.Capture (WinRT), enumerate displays/windows, picker
2. **Webcam** — MediaCapture (WinRT SDK projection) with device enumeration — ✅ **milestone 1 done**:
   1. TFM bumped to `net8.0-windows10.0.19041.0` (app **and** tests) so the WinRT projection resolves from the SDK reference packs — no NuGet package, no capability manifest (unpackaged desktop app)
   2. `MediaCaptureFrameSource` (CPU-first: `MemoryPreference = Cpu`, BGRA8 via `CreateFrameReaderAsync`), `MediaCaptureCameraEnumerator` (`DeviceInformation.FindAllAsync(DeviceClass.VideoCapture)`)
   3. `CameraManager`: refcounted by `DeviceId`, one shared `WriteableBitmap` app-wide, dispatcher-coalesced UI updates (~render rate, latest-frame drop), placeholder/`AppLog` + warning on failure
   4. `CameraPickerDialog` (mirror of `ReuseImageDialog`) — "Searching for cameras…" / list / "No cameras found" states
   5. One webcam app-wide: Add → Webcam greyed out once one exists ("it's already in your stream" tooltip); persisted `DeviceId` re-acquires after layout load
   6. Default placement 16:9 **480×270**, bottom-right, 32px margin; drag/resize/selection shared with Image sources
   7. **Clip shapes: Traditional + Round** (phone view dropped — the 9:16 phone output is the vertical output-crop tier); **mirror**; both persisted in the layout DB (schema v2) and toggled from the source chip
   8. **Background removal = milestone 2** (ONNX Runtime + DirectML, MediaPipe Selfie Segmentation) — not in this build
3. **Background / Image / Text** — static sources positioned/scaled/opacity
4. **Chat box** — rendered from the live chat poll (right panel is the same feed, raw)
5. **Scene compositing** — per-scene source layering (z-order = sources list order, top-to-bottom
   back-to-front), preview rendered via D3DImage or MediaElement
6. **Branding flash** — the topmost full-frame "made with ytLlive!" layer at ~25% opacity, ~1s on /
   300s off (see Monetization in `ai.md`), gated on `BrandFlashEnabled` + live/recording. Lives in the
   preview compositor now (`BrandFlashLayer` in `MainWindow.xaml` CanvasGrid, driven by
   `BrandFlashActive`/`BrandFlashTimer` in `MainViewModel`); the encoder output renders the same layer,
   and v0.2 local recordings carry it too
7. **Drag/drop placement & reorder** — intuitive, visual (per design principle):
   1. **Preview:** click-drag a source in the center panel to reposition it; resize via handles
   2. **Scenes list:** drag rows to reorder scenes
   3. **Sources list:** drag rows to reorder sources (this *is* the z-order) — implemented

---

---

## TASK 4 — RTMP Ingest to YouTube

**Goal:** Push encoded video to YouTube's RTMP ingest.

### Status: 🔶 In progress

1. ✅ **Ship step 1 — the output compositor SHIPPED** (2026-08-10)
2. ✅ **Ship step 2 — the FFmpeg locator SHIPPED** (2026-08-10)
3. ✅ **Encoder + RTMP push SHIPPED** (2026-08-12) — the FFmpeg subprocess: raw BGRA frames via stdin, stderr health parsing, FLV mux + push to the ingestion URL (see the ship step 3 plan below)
4. ✅ **WASAPI audio capture SHIPPED** (2026-08-12) — NAudio loopback (desktop/game) + the picked mic feeding `AudioLevel`, so the realtime meter comes alive (see the ship step 4 plan below)
5. ✅ **Frame-pipeline wiring SHIPPED** (2026-08-12) — `CameraManager`/`ScreenCaptureManager` → compositor resolver → encoder, driven by a paced `FramePump` (see the ship step 5 plan below)
6. ✅ **Health stats SHIPPED** (2026-08-13) — `FramePump.HealthUpdated` (encoder's parsed bitrate/FPS/dropped/duration, already forwarded from `FfmpegEncoder.OnStderrLine`) now lands in the bottom bar: `MainViewModel.OnFramePumpHealthUpdated` marshals to the UI thread (the stderr loop raises on a background thread) and copies into `CurrentHealth` (the bottom bar's existing binding); `ResetHealth` zeroes dropped/duration on go-live and on End so stats never linger from a previous session (bitrate/FPS stay on the tier's targets). The bar lights up with real values once TASK 9 supplies the RTMP URL (until then the pump skips the encoder and the bar shows the tier's targets)
7. ✅ **One-click go live + private-only enforcement SHIPPED** (2026-08-14) — the Go Live dialog is **locked to Private** (no dropdown, `GoLiveViewModel.Visibility` is a get-only "Private"); `YouTubeStreamService.CreateBroadcast` **always sends `privacyStatus = "private"`** (dialog + service enforcement, requirement 8 — nothing can go out non-private) and gained an injectable `HttpClient? http = null` seam for tests; `BeginGoLive` now calls `CreateBroadcastAsync` and remembers `_currentBroadcastId` for TASK 9's bind/transition (failure → `StreamStatus.Error`, never a crash; `StopStream` clears the ID); the REC sign shows a **PRIVATE badge** (dark-red border, next to REC, `IsLivePrivate`) when the live stream is private; settings' dead "Default Visibility" dropdown + `MainViewModel.Visibilities`/`DefaultStreamVisibility` removed. The broadcast-insert integration test asserts the request body carries `"privacyStatus":"private"` (2 new tests → 173 passing, 0 warnings)

The pipeline chain the encoder needs doesn't exist yet: **scene compositing** (the master 1920×1080 frame
without the preview's editing chrome) → **audio capture** (WASAPI, feeds the meter) → **H.264+AAC encode**
→ **vertical-tier crop/scale** → **RTMP push** → **health stats** into the bottom bar. Nothing can encode
until a frame source exists, so the compositor is ship step 1. The pipeline is
`CameraManager + ScreenCaptureManager → compositor resolver → compositor → encoder → RTMP`.

### Requirements:

1. **Encoding** — H.264 (hardware via NVENC/AMD, fallback x264) + AAC audio; **must comply**: keyframes ≤ 4s (gopSizeLong), closed GOP, AAC/MP3 @ 44.1/48kHz, mono/stereo only. **License posture (decided): GPL-free build** — NVENC (NVIDIA) / QSV (Intel) / AMF (AMD) + OpenH264 software fallback + built-in AAC; no libx264 (GPL contaminates a paid product). Output containers are identical either way (H.264+AAC in `.flv` for RTMP, `.mp4`/`.ts` for VOD) — the format is NOT the differentiator, the license and per-GPU quality are. **License guardrails (never violate — see `ai.md` → "Licensing — do not violate"):** only BtbN `lgpl`/`lgpl-shared` builds; never GPL (gyan.dev) or `nonfree` (fdk-aac); never static for distribution (LGPL §6 relink material); never link FFmpeg into the app; never drop `THIRD-PARTY-NOTICES.txt` from the app/About screen.
2. **RTMP push** — **FFmpeg subprocess (decided)**: app feeds raw frames via stdin, parses stderr for health; one battle-tested binary does encode + FLV mux + push + reconnect. **Binary distribution (decided): check-then-pull** — probe `where ffmpeg`/PATH at first go-live; if absent, download a **pinned** build (**BtbN LGPL-shared win64** zip, ~75 MB — gyan.dev's builds are GPLv3 and ship libx264, which violates the license posture; BtbN's LGPL variant drops x264/x265 while keeping NVENC/QSV/AMF + libopenh264 + native AAC) to `%APPDATA%\ytLlive\tools\ffmpeg.exe` (extract `ffmpeg.exe` **plus the `libav*.dll` family**) and cache it, offline-friendly. Behind an `IFfmpegLocator` seam so tests fake it (ship step 2, below). Push goes to the cached reusable stream's ingestion URL
3. **Quality ladder** — the offered tiers, with **1080p60 @ 8 Mbps as the standard/default**:
   1. 720p30 @ 6 Mbps
   2. 720p60 @ 6 Mbps
   3. 1080p30 @ 8 Mbps
   4. **1080p60 @ 8 Mbps** (default — mainstream ceiling, GPU hardware-encoded so the gaming
      machine never notices; upload headroom stays comfortable)
   5. Vertical 1080×1920 @ 60fps @ 8 Mbps (9:16 phone tier)
   The composition master is always 1920×1080; a tier is an output rect + target resolution
   (see `ai.md` "Resolution tiers"). Vertical output = the centered 607×1080 crop of the master
   scaled to 1080×1920 (semi-crop preview is already implemented; the encoder applies the same rect).
   1080p60 is the ceiling by design — "if you want 1440 or 4K or 8K → OBS is your solution"; the app
   targets the most mainstream creator, not power users.
   Ladder is sculpted by a **cached probe** (IP-only TCP vs public ingest host; no auth required).
   Quality is greyed out while live because the declared resolution can't change mid-stream — but
   with `variable`, we can **auto step-down** bitrate/resolution on the fly with zero API calls
   (no stream recreation); 60fps presumes a hardware encoder — no hardware encoder → auto
   fallback to 720p60/1080p30
4. **Stream key management** — reuse the cached reusable stream (one per channel) instead of creating a new one per go-live; prefill default YouTube ingest URL `rtmp://a.rtmp.youtube.com/live2`
5. **Health stats** — bitrate, FPS, dropped frames reported live in the bottom bar (encoder-side)
6. **One-click go live** — defaults that work out of the box
7. **Audio capture (feeds the meter — this task ships the wiring)** — WASAPI loopback (desktop/game at unity, zero UI — "it just is") + the picked mic (`MicSourceName` from the `MicPickerDialog`). The mic capture feeds `AudioLevel` so the realtime meter comes alive (today it reads 0 — the mixer feed is pending, see `ai.md` audio notes). AAC mono/stereo @ 48 kHz per the compliance rules.
8. **Private-only go live until v1 (reputation guard, decided 2026-08-10)** — until the v1 release, go-live is **locked to private streams only** so a software error can never publish something public/unlisted that damages the creator's reputation. RTMP push itself has no privacy — privacy lives on the YouTube **live broadcast object**, which this app already controls via its OAuth API calls. So the lock is purely API-side: the Go Live flow always creates/updates the broadcast with `privacyStatus = "private"` and a guard **refuses** to set anything else (same spirit as the Live-only backdrop policy). The UI shows a clear "PRIVATE" badge next to the stream state so the creator always knows who can see them. Enforcement must be verifiable in the auth-service tests (fake the broadcast-insert/update call, assert `privacyStatus` is forced to private).
9. **v1 release gate: bundle the full license texts (decided 2026-08-10)** — `THIRD-PARTY-NOTICES.txt` currently links the canonical license texts rather than embedding them. At the **v1 (GA) release**, the full texts of every license it names (LGPL v2.1+, BSD-2-Clause, MIT, Apache-2.0) MUST be bundled alongside it (shipped in the app output, e.g. a `licenses/` folder next to the notices file, still reachable from the About screen). This is a **release blocker for v1, not a task to queue early** — do it in the release pass. The repo should treat this like the private-only go-live gate: a checkbox that cannot silently lapse.

#### Ship step 1 — Scene compositor (the frame source)

**Goal:** a pure-CPU software compositor producing the encoder's master frame (BGRA8, the `VideoFrame`
seam) from the scene model. The preview stays XAML (the editing view); the compositor is the **output
view** — WPF's `RenderTargetBitmap` can't be used (software-rendered + captures chrome). Two renderers
must agree, so the XAML (`MainWindow.xaml` CanvasGrid + element DataTemplate) is the contract.

**Decisions (locked 2026-08-10):** **Path A CPU blitter** — GPU effort belongs to NVENC (the encoder),
not composition; with an FFmpeg subprocess the master crosses a CPU readback to the pipe every frame
anyway, so GPU compositing buys ~nothing at this layer count (2-3 live layers; static layers
pre-composite once). A D3D11 compositor can replace this one later **behind the same seam** (the CPU
master buffer stays the contract). **Render the output rect directly**: compositor is constructed with
`CompositorOptions {SourceRectX/Y/W/H, OutputWidth, OutputHeight}`; 16:9 tiers = full 1920×1080 1:1;
vertical (9:16) = composite the centered 607×1080 crop then bilinear-upscale to 1080×1920. Reuses
`MainViewModel.OutputRectX/Y/W/H` (note `(1920−607)/2 = 656.5` → align to integer pixels for output).

**Render spec (back → front, mirror the XAML exactly):**
1. Backdrop — the Live scene's `IsBackdrop` Source (`CaptureKey` → live frame), `UniformToFill`
   full-frame (XAML's separate `BackdropImage` layer; the backdrop *element* renders nothing — its
   DataTemplate Image is Collapsed for DisplayCapture).
2. Background — the scene's `Background` Source, `UniformToFill` full-frame (the `ActiveBackgroundImage`
   layer, not per-element).
3. Elements in `Scene.Elements` order (back→front), skip `IsVisible=false`. What actually renders:
   1. `Source` Type `Image` → static asset, `UniformToFill` cover-crop into (X, Y, W, H)
   2. `WebcamSceneConfig` → latest frame by `DeviceId`: Traditional = `UniformToFill` rect; Round = circle
      diameter `min(W,H)` (alpha 0 outside — true circle, not oval); mirror = horizontal flip around
      element center (`MirrorScale`); opacity = per-pixel multiply (content + border); border = stroked
      rect / centered circle at `RoundBorderSize`, width `BorderWidth`, alpha `BorderOpacity`
   3. `Background` / `IsBackdrop` / `TextOverlay` are NOT per-element (layers above; Text not shipped)
4. Branding flash — pre-rendered full-frame "made with ytLlive!" at 25% alpha when live +
   `BrandFlashEnabled` + timer active. Passed in as a `VideoFrame?` (compositor core stays pure byte-math,
   no WPF; likely a bundled asset rather than runtime text rendering).
5. NOT in output (preview chrome only): SelectionOverlay, DimRects, output-rect outline, badge, placeholder.

**New files (all in `Services/Compositor/`):**
1. `SceneCompositor.cs` — `Render(Scene, frameFor: Func<SceneElement, VideoFrame?>, flashFrame:
   VideoFrame?, CompositorOptions) → VideoFrame` (output-sized). The caller's `frameFor` resolver maps
   each element to its frame (webcam → DeviceId, image → AssetId via `StaticPixelCache`, backdrop →
   CaptureKey) — the compositor stays pure/hermetic/no WPF.
2. `CompositorOptions.cs` — source-rect + output W×H.
3. `StretchMath.cs` — `UniformToFill` cover-crop, ellipse mask, bilinear scale (pure, unit-tested).
4. `StaticPixelCache.cs` — asset `byte[]` → cached BGRA `VideoFrame` (WPF `BitmapDecoder` + `CopyPixels`,
   decode once per content hash).

**Test plan (Good Dog Rule — ONE integration test):** `SceneCompositorTests` — a scene with backdrop
(solid red fake frame) + round webcam (solid green) + image (solid blue) → render 16:9 master → assert
per-layer probe pixels (corner = backdrop color, element center = webcam color, outside the round clip =
backdrop color, mirrored element swaps left/right); a vertical-tier variant asserts 1080×1920 output +
crop fidelity. Focused unit tests on `StretchMath`. Tests push frames directly — no capture managers
involved (they wire in a later step).

**Same-PR housekeeping:** fix the stale comment `MainViewModel.cs:324` ("shown under the meter on line 2"
→ "shown left-justified INSIDE the meter bar" — `ai.md` is the authority); this task's requirements now
include the explicit audio-capture/meter wiring (#7 above).

**Out of scope (later ship steps):** FFmpeg locator + license posture (covered in requirements 1-2),
encoder + RTMP push, WASAPI audio capture (loopback + mic) feeding `AudioLevel`, wiring
`CameraManager`/`ScreenCaptureManager` into the frame pipeline, brand-flash timer wiring, health stats
(bitrate/FPS/dropped).

**Built (2026-08-10):** all four files shipped in `Services/Compositor/`, `SceneElement.TryGetBorderColor`
made public (shared hex parse with the compositor — no duplicated color parsing), the stale
`MainViewModel.cs:324` comment corrected, and the pre-existing CS1998 in `YouTubeAuthServiceTests`
cleaned up — build **0 warnings**. Tests: the `SceneCompositorTests` integration test (full-scene master
pixels, vertical tier, flash) + 4 `StretchMath` units — **72 passing**.

#### Ship step 2 — FFmpeg locator (the encoder's binary)

**Goal:** resolve a usable `ffmpeg.exe` on demand (the encoder's one external dependency), never shipping
a binary in the repo. Returns an absolute path; downloads only when neither PATH nor the local cache
provides one.

**Decisions (locked 2026-08-10):**
1. **BtbN LGPL-shared win64 build** — not gyan.dev (gyan's "essentials" is GPLv3 and ships libx264, which
   violates requirement 1's license posture) and **not the static lgpl build**: LGPLv2.1 §6 wants
   relinkable object files for static linking, but the **shared** (dynamic-DLL) variant sidesteps that —
   compliance is "license text + source offer + unmodified binaries" (see `THIRD-PARTY-NOTICES.txt` and
   `ai.md` → Licensing). Drops libx264/libx265 while keeping NVENC/QSV/AMF, libopenh264 (the LGPL-legal
   H.264 software fallback) and native AAC — exactly the requirement-1 encoder profile.
2. **Pinned URL** — `https://github.com/BtbN/FFmpeg-Builds/releases/download/autobuild-2026-08-09-13-03/ffmpeg-master-latest-win64-lgpl-shared.zip`
   (~75 MB zip — earlier "~30 MB" estimate corrected). A dated autobuild tag is immutable; BtbN retention
   keeps the last 14 daily builds + each month-end build for 2 years, so a cold cache after retention
   expiry 404s — a logged, recoverable failure (the seam throws; the encoder step surfaces it). Once
   cached, the URL is never touched again. The pin is a single `const`, bumpable in one place — and must
   always stay on the **shared** variant (never `gpl`, `nonfree`, or static; see ai.md Licensing).
3. **Check-then-pull order** — (1) PATH probe (the user's own install wins), (2) cached
   `%APPDATA%\ytLlive\tools\ffmpeg.exe`, (3) download + extract. Extract `ffmpeg.exe` **plus the
   `libav*.dll` family** (the shared build's bin/ folder; Windows resolves the DLLs from the exe's own
   directory) into a staging dir then move into place — a crash never leaves a corrupt or partial cache.
4. **Seam** — `IFfmpegLocator.LocateAsync(CancellationToken)`: search dirs, tools dir, and the downloader
   (`Func<string, CancellationToken, Task<byte[]>>`) are constructor-injected with production defaults, so
   tests fake the network (feeding a real in-memory zip) and never touch disk outside a temp dir.

**New files (all in `Services/Encoder/`):**
1. `IFfmpegLocator.cs` — the seam.
2. `FfmpegLocator.cs` — the impl (PATH probe → cache → pull+extract exe + DLLs), failures logged via `AppLog`.
3. `THIRD-PARTY-NOTICES.txt` (repo root) — the LGPL/BSD/MIT notices + source offer, copied to the build
   output. *(Surfacing changed on 2026-08-13: the top-bar About button that opened the file in the OS
   viewer is GONE — the notices are reachable in-app via the logo → About overlay instead.)*

**Test plan:** the hermetic integration test drives the full decision ladder against a temp tools dir and
a fake downloader returning a real in-memory zip (`.../bin/ffmpeg.exe` entry): PATH hit wins without
downloading, cache hit skips the network, cold cache downloads → extracts → `ffmpeg.exe` lands in the
tools dir, and a second call serves the cache (downloader invoked exactly once). Focused unit tests:
**shared-build DLLs extract alongside the exe**, empty zip throws, missing entry throws, empty download
throws, downloader failure propagates, zero-byte cache is refreshed.

**Same-PR housekeeping:** requirement 2's stale binary facts corrected in this plan (~30 MB → ~75 MB zip;
"gyan.dev/BtB N" → BtbN LGPL-shared only, with the why); the "never do" licensing guardrails recorded in
`ai.md` so the reasoning survives.

**Out of scope (later ship steps):** the FFmpeg subprocess encoder (frames in via stdin, stderr health
parsing), RTMP push, WASAPI audio capture, the frame-pipeline wiring, health stats.

**Built (2026-08-10):** `IFfmpegLocator` + `FfmpegLocator` shipped in `Services/Encoder/`, pinned to the
**lgpl-shared** build `autobuild-2026-08-09-13-03` (extracts `ffmpeg.exe` + the `libav*.dll` family via a
staging dir). `THIRD-PARTY-NOTICES.txt` (repo root) ships to the build output; the "never do" licensing
guardrails are recorded in `ai.md` — build **0 warnings**.
Tests: the hermetic `FfmpegLocatorTests` integration test (PATH → cache → download decision ladder with a
fake downloader serving a real in-memory zip) + edge/unit cases (shared-build DLL extraction, zero-byte
cache refresh, empty payload, missing zip entry, downloader failure) — **78 passing**.

#### Ship step 3 — Encoder + RTMP push (the FFmpeg subprocess)

**Goal:** encode raw BGRA master frames into H.264+AAC FLV and push them to the reusable stream's RTMP
ingestion URL — one battle-tested subprocess doing encode + mux + push + reconnect, the app feeding
frames via stdin and parsing stderr for health (req 2).

**Decisions (locked):** the encoder is a thin orchestrator over `ffmpeg.exe` — no H.264/AAC code in the
app. Arguments (pure `FfmpegArgs.Build`): `-re -f rawvideo -pix_fmt bgra -video_size WxH -framerate FPS
-i pipe:0` (frames in), a **silent placeholder audio track** via `-f lavfi -i anullsrc` (the WASAPI
capture step replaces this input), `-c:v <encoder> -b:v K -maxrate K -bufsize 2K` + **`-g fps×4`
`-keyint_min fps×4` `-sc_threshold 0` `-bf 0` `-pix_fmt yuv420p`** (the keyframe ≤4s / closed-GOP /
H.264 compliance), `-c:a aac -ar 48000 -ac 2`, `-f flv <rtmpUrl>`. Encoder choice is **probed from the
binary's `-encoders` listing** (`FfmpegEncoderPicker`, pure): hardware NVENC → QSV → AMF, then OpenH264
software fallback — **never libx264** (GPL; see `ai.md` → Licensing). The seam (`IFfmpegEncoder` +
`IEncoderProcess`, constructor-injected locator + process factory) keeps it hermetic — tests fake the
whole subprocess (probe + encoder), no real binary.

**Behavior:** `StartAsync` (locate → probe → spawn → stderr loop), `SubmitFrameAsync` (serialized BGRA
stdin writes, ~2 Hz health via `HealthUpdated`/`StreamHealth` — bitrate/FPS/duration/dropped-from-frame-
count), `StopAsync` (stdin EOF → ffmpeg finalizes + exits by itself; 10s watchdog kill), `ProcessFailed`
on a non-zero unexpected exit.

**Built (2026-08-12):** `EncoderOptions` + `IFfmpegEncoder`/`FfmpegEncoder` + `IEncoderProcess`/
`FfmpegEncoderProcess` + pure `FfmpegArgs`/`FfmpegProgressParser`/`FfmpegEncoderPicker` in
`Services/Encoder/`. Not yet constructed by the app (the frame-pipeline wiring, ship step 5, owns it).
Tests: `FfmpegEncoderTests` integration (probe → spawn with NVENC preferred → frames into stdin →
progress parsed → graceful stop, no kill) + units (args compliance/GOP, progress parser, picker
preference + GPL guard, no-URL/not-running/noop stops, process-death `ProcessFailed`) — **122 passing**.

#### Ship step 4 — WASAPI audio capture (the meter comes alive)

**Goal:** capture desktop/game audio (loopback) and the picked mic, feed the mic level into `AudioLevel`
so the realtime meter reads something other than 0, run capture **only while live** (req 7).

**Decisions (locked):**
1. **NAudio `NAudio.Wasapi` 2.2.1** — the wasapi feature package (not the `NAudio` meta-package): it
   carries the capture types (`WasapiCapture`/`WasapiLoopbackCapture` + the MMDevice enumeration) with
   `NAudio.Core`/`NAudio.Asio` pulled in transitively. MIT — recorded in `THIRD-PARTY-NOTICES.txt` (item 9).
2. **`IAudioSource` seam** (`Start`/`Stop`/`SampleReady`/`Failed`, IDisposable) — the app consumes the
   seam; the two WASAPI implementations wrap NAudio; tests inject hermetic fakes (no real audio devices,
   no timers). Loopback = `WasapiLoopbackCapture` on the default render device; mic = `WasapiCapture`
   with the NAudio device resolved by `FriendlyName` matching `MicSourceName` (the app only persists the
   DisplayName), falling back to the default capture endpoint. Mic device resolution is re-read at each
   `Start` via a name provider so a mic picked mid-session takes effect next go-live.
3. **`AudioMixer` owns both sources** — starts/stops both with go-live (`BeginGoLive` success → `Start`,
   `StopStream` → `Stop`). Mic samples feed a pure `AudioLevelMeter` (RMS, exponential smoothing) and
   raise `MicLevelChanged`, marshalled to the UI thread into `AudioLevel`; desktop samples are currently
   dropped (consumed by the encoder's AAC mix in a later step). Capture failures are logged via `AppLog`
   (mic failure also zeroes the meter); loopback failure doesn't kill the mic.
4. **Byte→float** — pure `WaveToFloat.Convert` handles the WASAPI mix formats: IEEE float 32-bit (direct)
   and PCM 16-bit (normalized to -1..1), including `WaveFormatExtensible` with the IEEE-float subformat
   GUID. Trailing partial samples are ignored.

**Built (2026-08-12):** `Services/Audio/` ships `IAudioSource` + `AudioSample`, `WasapiLoopbackAudioSource`,
`WasapiMicAudioSource`, `AudioMixer`, `AudioLevelMeter`, `WaveToFloat`; `MainViewModel` constructs the
mixer (mic source fed `() => MicSourceName`), starts it on go-live and stops it on end-stream, and maps
`MicLevelChanged` → `AudioLevel`. A pre-existing CS8602 in `FfmpegEncoder.cs:139` surfaced during this
step's rebuild and was fixed (`process!`) — build **0 warnings**. Tests: `AudioMixerTests` (mixer
lifecycle/forwarding/failure against fakes, meter RMS/smoothing/reset, `WaveToFloat` float/PCM16/
extensible/truncation) — **139 passing**.

**Deferred (later ship steps):** wiring the desktop-capture samples into the encoder's AAC mix (replaces
the `-f lavfi -i anullsrc` placeholder; the encoder construction itself shipped in ship step 5).
*(The "capture while not live" + "audio UI beyond the mic controls" deferrals were SHIPPED on the
2026-08-13 game audio bar branch — capture is now always-on for preview and the game bar is the second
audio UI. The mixer's short-circuit meter fix + `Started`/`RestartMic` seams live in the same branch.)*

#### Ship step 5 — Frame-pipeline wiring (the encoder gets a frame source)

**Goal:** the chain `CameraManager`/`ScreenCaptureManager` → compositor resolver → encoder, driven while
live by a paced frame pump: snapshot the active scene → resolve each element to its latest frame →
composite into the tier's output frame → pace into the encoder's stdin at the tier's FPS.

**Decisions (locked via user Q&A, 2026-08-12):**
1. **Video pipeline first** — the `-f lavfi -i anullsrc` silent track stays; mixing the loopback/mic
   WASAPI samples into the encoder's AAC track is its own later step.
2. **RTMP URL via a provider seam** — `MainViewModel._rtmpUrlProvider` is a `Func<string?>` returning
   null today (the reusable stream's ingest URL lands with TASK 9); when it yields null the pump logs
   and skips the encoder entirely, so go-live runs the existing visual flow without pushing.

**Design:**
1. `Services/Encoder/FramePump.cs` — the frame producer. All collaborators constructor-injected seams
   (`Func<Scene?>`, `Func<SceneElement, VideoFrame?>` resolver, `Func<CompositorOptions>`,
   `Func<EncoderOptions?>`, `Func<IFfmpegEncoder>`, `Action<string>` log, injectable pacing delay) so it
   stays free of WPF and of the capture managers and is hermetic in tests. `StartAsync` never throws
   (failures log + surface via `Failed` — the VM fires-and-forgets from the sync command handler);
   loop = snapshot → render → `SubmitFrameAsync`, paced at `1/options.Fps` (default `Task.Delay`; tests
   inject `Task.Yield`). `StopAsync` stops the encoder (closes stdin) BEFORE awaiting the loop — closing
   stdin unblocks a write stuck on pipe backpressure, so stop can't deadlock on the pump. `ProcessFailed`
   self-stops the pump. `HealthUpdated` forwards the encoder's stats (ship step 6 binds the bottom bar).
2. `ScreenCaptureManager.GetLatestFrame(key)` — mirrors `CameraManager.GetLatestFrame(deviceId)`; the
   backdrop's live frame for the compositor.
3. `MainViewModel` — owns the resolver (`WebcamSceneConfig` → `GetLatestFrame(WebcamId)`;
   `Source.IsLiveCapture` → `GetLatestFrame(CaptureKey)`; image/background → `StaticPixelCache.Get(AssetId)`),
   builds `CompositorOptions` from the tier + `OutputRect*` (doubles rounded to ints — the vertical
   607.5 half-pixel crop rounds to a perfectly-centered 608), builds `EncoderOptions` from the tier when
   the URL provider returns one, constructs the real `FfmpegEncoder(new FfmpegLocator())`, starts the
   pump on go-live, stops it on end-stream, disposes in `Shutdown`, and flips `StreamStatus.Error` when
   the pump fails while live (minimal — detailed health surfacing is ship step 6).

**Test plan (Good Dog Rule — ONE integration test):** `FramePumpTests.Start_CompositesScene_FeedsEncoder_StopsCleanly`
drives the full lifecycle against fakes — real `SceneCompositor` + real `FramePump`, fake `IFfmpegEncoder`
— asserting the composited red backdrop frame actually reaches the encoder at the tier size and that stop
tears everything down. Units: no-URL start skips the encoder, re-entrant start/stop no-ops, encoder
start-failure raises `Failed` + disposes, `ProcessFailed` self-stops the pump, `HealthUpdated` forwards.
`ScreenCaptureManagerTests.GetLatestFrame_ReturnsLatestPump_UntilReleased` pins the new accessor.

**Out of scope (later ship steps):** the loopback/mic → AAC mix (replaces `anullsrc`), health stats in the
bottom bar (ship step 6), scene-switching transitions, and any flash-frame wiring.

**Built (2026-08-12):** `FramePump` shipped in `Services/Encoder/`, `ScreenCaptureManager.GetLatestFrame`
added, `MainViewModel` wired end-to-end (resolver + both option builders + pump lifecycle), `FramePumpTests`
(7) + `GetLatestFrame` test (1) added — build **0 warnings**, **147 tests passing**. Known consideration:
the pump reads the active scene on a background thread while the UI can still edit it; a concurrent-mutation
exception is contained (logged + `Failed` + pump stops) rather than crashing.

#### Ship step 5.5 — Social bar bug fixes + the bar on the live output (2026-08-13)

**Bug 1 — bar wouldn't reliably change position (root cause found, then simplified):** the original
drag set `Canvas.SetTop(bar, …)` with a local value, which permanently overrides the
`Canvas.Top="{Binding SocialBarTop}"` binding — the release-time `SetSocialBarPosition` →
`PropertyChanged(SocialBarTop)` could never beat it. First fix added direction-snapping during the drag
(`SocialBarSnap.Decide`, ±6px deadzone) + `bar.ClearValue(Canvas.TopProperty)` on release — but that
still misbehaved for shaky hands (jitter around the deadzone: it snapped up reliably, then refused to
come back down and snapped back to top). **Superseded by a click-toggle (KISS, user decision):** clicking
the bar in the preview flips it top ⇄ bottom (`MainViewModel.ToggleSocialBarPosition` → the existing
`SetSocialBarPosition`), the bar rides `{Binding SocialBarTop}` alone (no local values, no deadzone, no
jitter sensitivity), and `SocialBarSnap` was removed. The `ClearValue` lesson stands: never set a local
value on a property the binding owns.

**Bug 2 — Mastodon showed the generic 7-star honeycomb (root cause found):** the DB row
`@gramps@llamachile.tube` had `Software = NULL` — nodeinfo was only ever resolved against the identity domain
(`llamachile.tube`, a landing page), never probed for the real instance at `mastodon.llamachile.tube`.
Fixed on three fronts: `HttpSocialValidator` now **probes well-known subdomains** (mastodon. → social. →
… `FediverseSubdomainCandidates`) when the identity domain and its redirect both come up empty, under a
~15s linked-CTS budget, with an optional `Action<string>` log; `MainViewModel` **heals** any fediverse entry
missing a software name on layout load (`HealFediverseSoftwareAsync` — static, testable; instance wrapper
runs it off the UI thread, applies via the dispatcher, saves); `SocialEntry.FediverseSoftware` is now
**settable** and raises `PropertyChanged` for `LogoData`, so the heal updates the icon in place. If the user
later re-saves the entry with the icon fixed, the name persists with it.

**Compositor rendering (user-approved scope):** the social bar now appears **on the live output**, not just
the preview — `Compositor/SocialBarRenderer.cs` rasterizes the entries into a transparent straight-alpha
BGRA strip (1920-wide, 40px content + 24px glow pad, green `#2ecc71` glow baked in) via `RenderTargetBitmap`
(WPF glue like `StaticPixelCache`; the compositor core stays pure). `SceneCompositor.Render` takes optional
`socialBarFrame` + `socialBarTop` (master space) and blits it **last — above the branding flash** (the old
`BlitFlash` generalized to offset `BlitOverlay`). `FramePump` gains a `socialBar:` seam
(`Func<(VideoFrame?, SocialBarPosition)>`, re-read every frame) and places the bar at `0` or
`SourceRectHeight − bar height`. `MainViewModel` owns the frame (`RenderSocialBarFrame`, re-rendered on
load/save/notify) and feeds the seam.

**Tests (+6 → 153 passing, 0 warnings):** settable `FediverseSoftware` updates `LogoData`,
subdomain-probe unit + null-when-silent unit, the branch's **one integration test**
`Socials_HealMissingFediverseSoftware_RoundTripsThroughDb` (temp-DB roundtrip: NULL software → healed via
the validator → persisted), compositor bar overlay (top/bottom + above-flash), `FramePump` bar pass-through
(Top then flipped to Bottom mid-run — the seam is re-read each frame), and both `ISocialValidator` fakes
(`FakeValidator`/`BlockingValidator`) gained `ResolveFediverseSoftwareAsync`. The drag-snap units
(`SocialBarSnap`) were removed with the click-toggle supersession.

**Not included (say the word):** rewriting the healed entry's `ProfileUrl` to `https://mastodon.llamachile.tube/@gramps`.

---

---

## TASK 5 — Layout Persistence (SQLite)

**Goal:** Scenes, sources, and asset bytes survive restarts; assets are always available.

### Status: ✅ Done

1. ✅ SQLite database (`Microsoft.Data.Sqlite`) at `%APPDATA%\ytLlive\ytLlive.db`; schema versioned via `PRAGMA user_version` (currently **v8**)
2. ✅ Assets live in the DB (BLOB keyed by SHA-256 content hash), never file paths — deleting the original file never breaks a scene
3. ✅ File-model save/open — the active layout file is tracked (default is the AppData DB); **Save Layout As… / Open Layout…** switch the active file; auto-save writes to whatever is active
4. ✅ Auto-save (invisible) — ~1.5s debounce on scene/source add/remove/reorder/rename/hide + any source transform change; flush on window close
5. ✅ Startup — load the active file; seed the five canonical scenes only when the DB is empty; (+) re-adds a missing canonical scene and is hidden once all five are present; adding beyond the five is rejected
6. ✅ Schema v1 → v9 — webcam columns (v2), singleton `Webcam` + per-scene `WebcamSceneConfig` (v3), `RectWidth`/`RectHeight` round-to-rect restore (v4), `Source.IsBackdrop` + `Source.CaptureKey` (v5), `Scene.HasBackdrop` — backdrop **Live-only by policy** (v6, one-time backfill + `EnforceBackdropPolicy` on every load), `Scene.HasSocialBar` (v7, dropped per-scene toggle — column back-compat, unread), `Socials.BarEnabled` (v8); the `SocialEntry.Software` fediverse-software column is a **column-presence migration** (commented v8→v9, no version bump — `user_version` stays 8); v9 = single-row `Music`. **Load-time rule:** sources load with `IsBackground` derived from `Type` (OR'd with the persisted column so legacy DisplayCapture backdrops keep their flag) — rows saved before the Type setter derived the flag heal on load
7. ✅ WindowHandle stays in-memory (per-session); save = transactional rewrite; orphaned assets pruned. **v9 lands in the TASK 8 audio milestone** (single-row `Music` — `TrackPath`/`IsEnabled`)

### Design decisions

1. **SQLite database** (`Microsoft.Data.Sqlite`) at `%APPDATA%\ytLlive\ytLlive.db`; schema versioned
   via `PRAGMA user_version`.
2. **Assets live in the DB, not on disk** — `Asset` table stores image bytes (BLOB) keyed by a
   SHA-256 content hash (unique). Identical image content collapses to one row regardless of file
   name — the 1:M resource memory model, enforced by the database. No file paths; deleting the
   original file never breaks a scene.
3. **File-model save/open** — the active layout file is tracked (default is the AppData DB).
   **Save Layout As… / Open Layout…** switch the active file; auto-save writes to whatever is active.
4. **Auto-save (invisible)** — ~1.5s debounce on scene add/remove/reorder/rename/hide, source
   add/remove/reorder, and any source transform change; flush on window close.
5. **Schema** — `Scene` (Id, Name, IsHidden, IsChatScene, HasBackdrop, HasSocialBar, SortOrder), `Asset` (Id, Hash, Data,
   PixelWidth, PixelHeight), `Source` (Id, SceneId FK cascade, AssetId FK, Type, Name, IsEnabled,
   X/Y/Width/Height/Opacity, MonitorIndex, DeviceId, ClipShape, IsMirrored, SortOrder), `Socials` (Id,
   BarPosition, BarJustify — back-compat, unread, BarEnabled added via `ALTER`), `SocialEntry` (Id,
   SocialsId FK cascade, Service, Handle, ProfileUrl, SortOrder) — `user_version` **8** (v1 → v2 =
   `ALTER TABLE` adds the two webcam columns; v3 = singleton `Webcam` + per-scene `WebcamSceneConfig`;
   v4 = `WebcamSceneConfig.RectWidth`/`RectHeight` for the round-to-rect restore; v5 = `Source.IsBackdrop`
   + `Source.CaptureKey` for the live-capture backdrop; v6 = `Scene.HasBackdrop` — the backdrop is
   **Live-only by policy** (one-time backfill turns Starting/BRB/Chat/Ending off and drops their backdrop
   sources; `EnforceBackdropPolicy` re-normalizes every load); v7 = `Scene.HasSocialBar` (per-scene toggle
   dropped — column back-compat, unread); v8 = `Socials.BarEnabled`). The `SocialEntry.Software`
   fediverse-software column is a column-presence migration (commented v8→v9, no version bump).
   `WindowHandle` stays in-memory (per-session). Save = transactional rewrite; orphaned assets pruned.
6. **Startup** — load the active file; seed the five canonical scenes
   (Starting/Live/BRB/Chat/Ending, `SceneCatalog`) only when the DB is empty. The (+)
   button re-adds a missing canonical scene and is hidden once all five are present;
   adding beyond the five is rejected — work with less, never more.

---

---

## TASK 6 — UI polish batch (scenes/sources rows, dedup naming, social bar)

**Goal:** clean up the two side lists and the social bar per gramps's review.

### Status: ✅ Done

1. ✅ Scene rows are pure selection rows — the per-row edit/trash/visibility icons and the inline rename TextBox are gone (`EditSceneCommand`/`RemoveSceneCommand`/`ToggleSceneVisibilityCommand` + handlers + `Scene.IsEditing` removed; `IsHidden` stays persisted + dims hidden rows)
2. ✅ Source rows gained the trio — edit (inline rename via new `EditElementCommand` + `SceneElement.IsEditing`), visibility eye (new `ToggleElementVisibilityCommand` flips `SceneElement.IsVisible`; the eye style now binds `IsVisible`, open/slashed + row dims to 0.45 when hidden), and the existing trash
3. ✅ Duplicate resource names get a no-space incrementing suffix via shared `NextSourceName` (Image, Image2, Image3…) — next free number derived from the names actually in the scene, so deleting a middle resource never collides (`AddSource` + `AddReusedImage` both use it)
4. ✅ Social bar renders the full validated handle — `MaxWidth=200` + `TextTrimming` removed from BOTH `SocialBarRenderer` and the preview template (mastodon `@gramps@…` no longer cuts off)
5. ✅ Side panels stay fixed-width (left 220 / right 300) — deliberate: they never re-layout on resize, the preview absorbs it
6. ✅ Focus-loss capture lag documented as a known OS limit in `ai.md` — deferred by user decision (no code change)

### Design decisions

1. **Next free number from names, not type counts** — the old scheme counted elements by `SourceType` (`count == 0 ? baseName : base+count+1`), which collided after deletions; the new helper scans actual names.
2. **One WPF App per AppDomain** — the real-App tests (round-clip + naming) share `RealAppHost` (a dedicated STA thread owning the single `App`) via the `RealApp` serial collection, instead of each calling `new App()`.

---

---

## TASK 7 — Meter scaling amplification (voice meter uses the full bar)

**Goal:** the mic (and game) meters feel light — speech peaks should peg into the red at maxed volume.

### Status: ✅ Done

1. ✅ `AudioLevelMeter.ToDisplay` now adds **+10 dB of input amplification** before the −60..0 dBFS → 0..1 log mapping (was raw dB): speech peaks (~0.2 RMS, −14 dBFS) read ~0.93 → red zone; normal speech (~0.05, −26 dBFS) ~0.73 → yellow; background noise ≤0.001 linear (−60 dBFS) still reads 0 (the meter never idles on it)
2. ✅ Unit tests updated to the new mapping + new `ToDisplay_Pushes_Speech_Peaks_Into_Red_At_Maxed_Volume` (0.2 → 0.92..0.95, 0.05 → 0.72..0.75)

### Design decisions

1. **Amplify at the mapping, not in the VM** — one knob (`ToDisplay`), shared by the mic bar and the game bar; the `× MicVolume` gain-on-noise behavior is untouched (raising the slider still moves ambient noise up the bar).
2. **+10 dB, not more** — louder boosts push quiet speech into the lower half and make the noise floor visible; +10 puts speech peaks solidly in red while idle stays at zero.

---

---

## TASK 8 — Audio milestone: real stream audio + voice filters + TRAX music (2026-08-14)

**Goal:** every audio issue done and tested in one branch — real mic/game audio reaches the encoder (replacing the `anullsrc` silence), `MicVolume`/`GameAudioVolume`/mute become real pre-AAC gains, TASK 10's voice filters land, auto-duck keeps the creator's voice over game + music, and a free background-music source ("TRAX") plays into the sound bar and the stream.

### Status: ✅ SHIPPED 2026-08-14 — 196 tests passing, 0 warnings (ONE integration test: `AudioPipelineTests.Mix_WithFiltersDuckAndGain_Lands_On_AudioPipe`)

1. ✅ **Real audio into the encoder** — the mixer's loopback samples were **dropped today** (`AudioMixer.OnLoopbackSample` metered only) and `MicVolume` was meter-only; `FfmpegArgs.cs:28` ran `-f lavfi -i anullsrc` (silence). Transport: **ffmpeg reads a Windows named pipe** — `-f f32le -ar 48000 -ac 2 -i \\.\pipe\ytllive_audio` replaces the anullsrc block, plus explicit `-map 0:v -map 1:a`; pipe name via `EncoderOptions.AudioPipeName` (`DefaultAudioPipeName = "ytllive_audio"`). Mixer stays **two inputs (mic + loopback)** — no N-source abstraction, no `StereoMixer` class. The VM owns the pipe lifecycle (`BeginGoLive` → `_audioMixer.StartLive(pipeName)`, `StopStream` → `_audioMixer.StopLive()` before the pump stops); `FfmpegEncoder.cs` is untouched.
2. ✅ **Honest gains reach the stream** — `MicVolume` scales the mic channel; `GameAudioVolume` + mute scale the loopback channel (the "mute in preview but stream still plays" footgun dies with it). One knob per input = KISS. Implemented as `Func<double>` gain seams on `AudioMixer` (`micGain`/`loopbackGain`), wired by `MainViewModel`.
3. ✅ **Voice filters (TASK 10, before the meter AND the mix)** — `VoiceFilterChain`: bass (`LowShelfFilter` 120 Hz +4 dB) → treble (`HighShelfFilter` 8 kHz +3 dB) → **noise gate** (pure C#, creator's choice) → compressor (threshold 0.5, 4:1). Pure stateful DSP (TDF2), sine-in unit tests. Meter stays post-filter.
4. ✅ **Auto-duck** — pure envelope (`AutoDucker`): mic RMS > 0.02 → game+music dip ×0.25 (~12 dB), attack 0.05 / release 0.005, recover on release. Always-on, no knobs. Strong form of the creator's "voice always over the game volume" idea.
5. ✅ **TRAX — background music, FREE** (keeps the one paid line = Alerts + flash removal). `MusicPlayer`: NAudio `MediaFoundationReader` (mp3/wav/m4a) → `VolumeWaveProvider16` at the hardcoded **0.20** (fixed, not changeable) → `WaveOutEvent` on the default device (added the sibling `NAudio.WinMM` 2.2.1 package — `WaveOutEvent` isn't in `NAudio.Wasapi`), loop on end. **No 3rd mixer input and no `MusicVolume`** — music plays on the desktop, the existing loopback picks it up: heard in headphones, the sound-bar meter bounces, and the stream carries it through the loopback channel (ducked with game when the voice is hot). Known wrinkle (out of scope): YouTube mutes VODs carrying copyrighted music — future "music on live, off VOD".
6. ✅ **TRAX footer control (final spec, agreed 2026-08-14)** — `YtButtonSecondary`, **status dot + "TRAX"** text, in the center footer stack beside MIC:
   - **Status dot** (same 8px Ellipse pattern as MIC/Socials): **red** no track loaded · **yellow** loaded not playing · **green** playing.
   - **Left-click** → toggle play/pause; no track loaded → opens the picker instead.
   - **Right-click** → always opens the in-app track picker (`TraxButton_PreviewMouseRightButtonUp`, code-behind pattern like `GameSpeaker_MouseLeftButtonUp`, `e.Handled = true` so no context menu).
   - **Tooltip** → playing/loaded track name; "No track — right-click to choose background music" when empty.
   - **No slider** — volume is the 0.20 constant. Picker = plain OS `OpenFileDialog` filtered to mp3/wav/m4a/aac/flac/ogg.
7. ✅ **Sound bar shows music** — `IsGameAudioBarVisible = gameDetectorProducingSound || isMusicPlaying`; relabelled "Game Audio Capture" → **"Desktop Audio"** (TRAX rides the same channel). **Follow-up (2026-08-15): the gating is gone — the game audio bar is ALWAYS visible** (the `IGameAudioDetector`/`GameAudioDetector`/`GameAudioHysteresis` stack + the VM's 250ms poll timer and their tests were deleted; the bar kept hiding the desktop meter when no full-screen game with sound was up, and the creator wants it pinned).
8. ✅ **Capture hardening (design changed at build time)** — the plan's "force IEEE-float 48 kHz on both WASAPI sources" was **dropped**: NAudio 2.2.1's `WasapiCapture` exposes no overridable `GetDefaultMixFormat`, so both sources capture the device's own mix format and the mixer's pure `TinyResampler` normalizes any rate/channel count to 48 kHz stereo (the resampler IS the design, not a fallback). Stop path disposes the audio pipe (EOF) in `MainViewModel.StopStream` before the pump stops, so both ffmpeg inputs end in order.
9. ✅ **Schema v9** — single-row `Music` (`TrackPath`, `IsEnabled`; volume is the 0.20 constant) + migration in `LayoutStore.cs` (`user_version` 9; `Save` gained an optional `Music? music = null` param so existing 3-arg callers still compile; load query + null reset).
10. ✅ **Docs in the same commit** — `ai.md` audio section rewritten ("one knob per input", 2-in mix, auto-duck, TRAX free, VOD-mute wrinkle), TASK 10's status, this task's status, HANDOFF.

**Files (new):** `Services/Audio/VoiceFilterChain.cs` (+ `LowShelfFilter`/`HighShelfFilter`/`NoiseGate`/`Compressor`), `Services/Audio/AudioRingBuffer.cs` (async-arrival source buffers), `Services/Audio/AutoDucker.cs`, `Services/Audio/TinyResampler.cs`, `Services/Audio/MusicPlayer.cs`, `Services/Audio/NamedPipeAudioWriter.cs` (+ `IAudioPipeWriter` seam), `Models/Music.cs`.

**Files (changed):** `AudioMixer.cs` (filter chain before meter+mix, loopback into the mix, gains via `Func<double>` seams, ducker, silence-filler so the pipe never stalls, `StartLive`/`StopLive`), `WasapiMicAudioSource.cs` (device mix format — resampler normalizes; no forced format), `FfmpegArgs.cs` (named-pipe input + `-map`, name via `EncoderOptions.AudioPipeName`), `EncoderOptions.cs` (`AudioPipeName`), `ytLive.csproj` (`NAudio.WinMM` 2.2.1 for `WaveOutEvent`), `LayoutStore.cs` (schema v9), `MainViewModel.cs`/`MainWindow.xaml`/`MainWindow.xaml.cs` (footer TRAX group, sound-bar visibility OR music, go-live starts the pipe, end closes it first).

**Testing (Good Dog Rule — ONE integration test):** `AudioPipelineTests.Mix_WithFiltersDuckAndGain_Lands_On_AudioPipe` — real filter chain + mixer + ducker + `NamedPipeAudioWriter`, fake `IAudioSource`s, test-side `NamedPipeClientStream` reads the bytes and asserts post-filter/post-gain/post-duck mixed stereo (ring buffers pre-filled so the first pipe tick already carries real audio — avoids a start-of-stream silence race). Units: each DSP stage (known sine-in → expected gain), ring buffer wrap/underflow/overwrite, ducker envelope, resampler (down/up/stateful/identity), `FfmpegArgs` pipe+map, schema v9 roundtrip + no-music-row. Existing tests stay green.

**Out of scope (this branch):** IP webcam (video-only when it lands — never an audio input), chat box source (TASK 3 item 18), alt-key crop, credits, background removal, music-off-VOD, `PremiumUrl` (TASK 10 seam).

---

---

## TASK 9 — YouTube Live Stream Management

**Goal:** Create/bind broadcasts, monitor YouTube-side stream health — the v3 way.

### Status: ⏳ In progress — items 1–3 SHIPPED (reusable stream 2026-08-16; report-by-exception health 2026-08-16); items 4–7 still open (each its own branch/PR)

1. ☑ **Broadcast creation** — title/description/privacy/scheduledStartTime via API, with the v3 flags above (SHIPPED: `CreateBroadcast` sends `enableAutoStart/Stop`, `enableMonitorStream=false`, `latencyPreference=low`, `selfDeclaredMadeForKids=false`)
2. ☑ **Reusable stream** — create once, cache + reuse; bind to broadcast (SHIPPED: `GetOrCreateReusableStreamAsync` lists-then-inserts the `variable`/`isReusable` stream, cached via `LayoutStore` Settings, bound at broadcast insert via `boundStreamId`; `_rtmpUrlProvider` yields the ingest URL so go-live actually encodes + pushes)
3. ☑ **Health monitoring** — poll `liveStreams.list` `healthStatus` + `configurationIssues[]`, surface banner only on warning/error (SHIPPED: `GetStreamHealthAsync(streamId)` 30s while live; pure `StreamHealthReporter.BannerFor` = report-by-exception; banner strip under the top bar, amber warning / dark-red error, via `HealthIssueBanner`/`HealthIssueBackground`; poll failures log-only; ONE integration test `GetStreamHealthAsync_Report_By_Exception_Banner_Only_On_Warning_Or_Error`)
4. ☐ Live chat — poll `liveChat/messages`, render in right panel, support Super Chat + membership badges
5. ☐ Error handling — the YouTube error codes: `errorStreamInactive`, `invalidTransition`, `redundantTransition`, `liveStreamDeletionNotAllowed`, `liveStreamModificationNotAllowed`, `liveBroadcastBindingNotAllowed`
6. ☐ **Visibility picker** — remove temporary "always Private" enforcement (shipped as test-only; now unlocked for v1). User picks Private/Unlisted/Public from the go-live dialog. Trivial: remove the hardcoded override in `YouTubeStreamService.CreateBroadcast` (currently `privacyStatus = "private"` regardless of dialog selection)
7. ☐ **Full broadcast form** — expose all YouTube API-supported fields in the go-live dialog. Core tab: title, description, visibility, made-for-kids, schedule (start + optional end). Advanced tab (expandable, sane defaults): latency (Normal/Low/Ultra-Low), DVR, embed, record-from-start, projection (rectangular/360°), closed captions, auto-start, auto-stop, monitor stream, region restrictions. Monetization via `liveBroadcasts.update` (insert-only on that resource) — separate step after broadcast creation. Remove unsupported `categoryId` (not a `liveBroadcast` field, silently ignored)

### Design decisions (v3)

1. **One-click go-live** — `liveBroadcasts.insert` with `enableAutoStart=true`, `enableAutoStop=true`, `enableMonitorStream=false`, `selfDeclaredMadeForKids=false`, `latencyPreference=low`. No `transition(live)` call, no testing stage, no liveStarting polling. Encoder starts → YouTube brings it live by itself.
2. **Variable reusable stream** — `cdn.resolution=variable`, `cdn.frameRate=variable`, `isReusable=true`. Create once per channel, cache ingestion URL + stream name, reuse for every broadcast. Any quality tier works without recreation; auto step-down needs no API calls.
3. **Report-by-exception** — poll `liveStreams.list`; banner only on `healthStatus` warning/error issues (`configurationIssues[]`). Bottom strip = YouTube logo + green/red connection dot (clickable → opens the dialog).
4. **One dialog, three states** — `not connected` (sign-in) / `connected-offline` (all editable) / `live` (title + description + visibility editable; quality + account greyed out). Both entry points (Start Stream button + bottom strip) open it; prefilled from saved session profile.
5. **Live edits** — `liveBroadcasts.update` with part=`snippet,status` for title/description/privacy.
6. **End stream** — stop encoder → `transition(complete)`, with `enableAutoStop` as the safety net.
7. **Broadcast ID == Video ID** — one ID to track status, health, and the auto-created VOD (`recordFromStart` + `enableDvr`).

### Requirements:

1. **Broadcast creation** — title/description/privacy/scheduledStartTime via API, with the v3 flags above
2. **Reusable stream** — create once, cache + reuse; bind to broadcast
3. **Health monitoring** — poll `liveStreams.list` `healthStatus` + `configurationIssues[]`, surface banner only on warning/error
4. **Live chat** — poll `liveChat/messages`, render in right panel, support Super Chat + membership badges
5. **Error handling** — the YouTube error codes: `errorStreamInactive`, `invalidTransition`, `redundantTransition`, `liveStreamDeletionNotAllowed`, `liveStreamModificationNotAllowed`, `liveBroadcastBindingNotAllowed`
6. **Visibility picker** — Private/Unlisted/Public from the go-live dialog
7. **Full broadcast form** — Core + Advanced tabs with all API-supported fields

---

---

## TASK 10 — Monetization: watermark-only subscription + Polar billing

**Goal:** annual subscription via Polar.sh that removes the branding watermark. All features are
free — the only difference between free and paid is the watermark.

**Business details (pricing, Polar product/checkout/discounts) in `MONETIZATION.md` (gitignored).**

**Polar product:** `d105dfa1-497e-423b-8cd4-e0ee2e3abbc0` (LlamaCasty, $99/yr, currently `private`)
**Checkout:** `llamacasty.com` → Polar hosted page (~80% configured)
**Discounts:** `LLAMAFOUNDER` (100% off, 50 uses, `once`), `LLAMA50` (50% off, 12 months, unlimited)
**Org ID:** `c05fb364-b967-4f6c-adf2-8a144e46d085` (org-scoped OAT — `organization_id` can be omitted from API calls)
**Key prefix:** `LCYT-`
**Validate endpoint:** `POST https://api.polar.sh/v1/customer-portal/license-keys/validate` (no auth required for client-side validation)

### Status: 🔶 In progress — steps 1–7 shipped, Velopack update URL pending

1. ✅ **Billing provider** — Polar (polar.sh) chosen and configured. Product, price, license key benefit, discounts, checkout link all created.
2. ✅ **License key entry + verification UI** — About overlay swap panel (same pattern as Licenses panel). Text input + "Activate" button + status message. "Enter License Key" button in the hub.
3. ✅ **Offline entitlement** — `LayoutStore` Settings table: `LicenseKey`, `LicenseValidatedAt`, `IsPremium`. 14-day offline grace period. Startup re-validates online, falls back to cache.
4. ✅ **BrandFlash → watermark toggle** — `IsPremium` property setter flips `BrandFlashEnabled = !value`. Flash stops immediately on premium activation. Flash asset VideoFrame rendering deferred to TASK 4 compositor.
5. ✅ **Remove social slot locks** — all 6 social bar slots open to everyone (no `IsPremium` gating on slots 3-6) — shipped as TASK 10c
6. ✅ **"Unlock Premium" button** — `PremiumUrl` set to Polar checkout; `IsPremiumAvailable` is true; button lights up in the About hub.
7. ✅ **Renewal/lapse handling** — startup re-validates against Polar API. Lapse → `IsPremium = false` → flash returns. Grace period: 14 days offline.
8. 🔶 **Velopack auto-updates** — NuGet packages + bootstrap in `App.xaml.cs`. Update URL self-hosted on DO droplet (pending configuration).

---

---

## TASK 11 — Post-pause polish batch: the creator's 8 review issues (2026-08-15, shipped)

**Status: ✅ SHIPPED 2026-08-15 — 197 tests passing, 0 warnings (ONE integration test:
`AudioPipelineTests.Mix_HonorsProviderGains_AndGameMute_KillsTheLoopback`).**

The creator reviewed the TASK 8 build and filed 8 issues. All fixed in one branch on `main`:

1. ✅ **Desktop/game audio volume slider had no effect** (headset OR stream) — the `AudioMixer`'s
   `micGain`/`loopbackGain` seams defaulted to unity because the VM never passed them; the sliders
   were decorative. Fixed: new `AudioGainProvider` (`Services/Audio/`) hands `MicMuted`/`MicVolume`/
   `GameMuted`/`GameAudioVolume` to the mixer at construction, read live each mix tick.
2. ✅ **Desktop/game mute button had no effect** — same root cause; `GameMuted` now zeroes the
   loopback on the stream. Locally, `MusicPlayer.LocalGain` (new) is scaled by the game bar on every
   volume/mute change + on TRAX load, so the creator **hears** the control work on the music (the
   track rides the loopback channel, so it ducks locally exactly as it does on stream).
3. ✅ **TRAX played once then stopped** — `MusicPlayer.OnPlaybackStopped` only looped when
   `Position >= Length`, unreliable for `MediaFoundationReader`; now any clean stop
   (`e.Exception == null`) rewinds + replays; only errors/explicit stops surface via `PlaybackEnded`.
 4. ✅ **TRAX/MIC buttons swapped** — TRAX no longer sits between MIC and the (mic-specific) meter;
    the footer's mic cluster is MIC + meter + mute + volume.
 5. ✅ **Mic source persists across restarts** — `LayoutStore` gained a `Settings` key/value table
    (`SaveMicSourceName`/`LoadMicSourceName`); the VM saves on pick and restores before the mixer's
    first `Start`, so a restart reconnects the same already-vetted device (green dot) or reports it
    missing (yellow) instead of falling back to the default endpoint.
 6. ✅ **TRAX moved into the game audio bar** — left of the "Desktop Audio" label in the preview
    overlay (the creator's follow-up pick), no longer in the footer; its tooltip teaches the clicks
    ("left-click pauses/plays, right-click chooses a track").
7. ✅ **Backdrop's icons shifted right** — the trash button's `Collapsed` released its column; a new
   `HiddenBoolToVisibilityConverter` keeps the slot reserved (`Hidden`), so edit/eye stay in their
   fixed columns for every source row.
8. ✅ **No separation between scenes and sources** — a 1px hairline with top/bottom padding now sits
   between the two listboxes in the left panel.

### Design decisions

1. **The gain seams are the one source of truth** — `AudioGainProvider` is a thin seam (four Funcs)
   so the mixer contract and the mute⇔zero-volume rule are testable without constructing the VM.
2. **Stream-honest AND locally audible** — the game bar's controls now do two things: scale the
   loopback on the stream and scale the music in the headphones. Native game audio is untouched
   (system output, OBS-style non-monitored); an OBS-style monitor loop is out of scope.
3. **Persist the DisplayName, not the device ID** — the FriendlyName match was already the mic's
   identity end-to-end; `Settings` just makes it survive restarts.

---

---

## TASK 12 — Master limiter on the live mix (2026-08-15)

**Queued by the creator during the TRAX discussion:** "should the soundtrack be limited to avoid
squandering resources / should it cap at 20% / how do the three sound events balance?" Review
conclusions (all three instincts checked out, only ONE real gap):

- **File size — no guard needed.** `MusicPlayer` uses `MediaFoundationReader`, which **streams from
  disk** (progressive source): memory is flat (~a few MB) regardless of file size; CPU negligible.
- **20% cap — already enforced by construction.** `MusicPlayer.MusicVolume = 0.20f` + music rides the
  SAME WASAPI loopback (and therefore the same gain) as game audio, so music:game is always exactly
  **0.20:1 at any slider position** — it literally cannot rise above 20% of the current desktop volume.
- **The gap:** `AudioMixer.FillAndMix` summed mic + loopback with **no output ceiling** — mic 100% +
  loud game/music could pass 0 dBFS and clip the AAC encode.

**Shipped:**
1. ✅ **`Services/Audio/MasterLimiter.cs`** (pure, unit-tested) — a **−1 dBFS ceiling** (`Ceiling =
   0.891`), **instant attack per frame** (a hot frame is scaled exactly to the ceiling — no overshoot),
   **smoothed release** toward unity so loud passages don't pump; gain never exceeds 1 (no boosting).
   Applied at the end of `AudioMixer.FillAndMix`, right before the pipe write.
2. ✅ **Unit tests** — over-ceiling frames trimmed to ≤ ceiling; sub-ceiling frames never boosted; gain
   recovers to unity after the loud frame ends.
3. ✅ **ONE integration test** (`MasterLimiter_CapsTheLiveMix_OnThePipe`) — real mixer + pipe harness:
   a 0.95 loopback bed (hotter than the ceiling) is capped to exactly 0.891 on the wire while staying
   audible.
4. ✅ **Docs in the same commit** — `ai.md` (go-live audio section), `Services/index.md` (new row).

No changes to `MusicPlayer`, the 0.20 cap, the ducker, or the meter zones. Build 0 warnings.

---

---

## TASK 13 — Social media launch kit

**Goal:** marcom/social media assets and strategy for v1 launch.

**Business details (positioning, messaging, platform strategy, launch assets) in `MARCOM.md` (gitignored).**

### Status: 🔶 Scoped — nothing built; queued after all v1 features ship

1. ☐ Product positioning & messaging (one-liner, elevator pitch, competitive positioning)
2. ☐ Social media swipe files (pre-written posts for supporters)
3. ☐ Launch day assets (demo video, screenshots, GIFs, social graphics, press kit)
4. ☐ Platform strategy (YouTube, Reddit, indie dev communities, Product Hunt)
5. ☐ Founder story (67-year-old dev building his own streaming app)
6. ☐ Email announcement templates
7. ☐ "Build in public" livestream angle (stream the coding of ytLlive with ytLlive)

---

## TASK 14 — Creator feedback batch: quick fixes (TRAX, meter, backdrop, sliders)

**Goal:** address creator's immediate UX feedback from testing session.

### Status: 🔶 In progress — Branch 2 shipped

1. ✅ TRAX volume — `LocalGain = GameAudioVolume * 0.2` so TRAX is 20% of the desktop audio slider (was 100%, now quieter)
2. ✅ TRAX tooltip — replaced `ToolTip` binding with `ToolTipService.ToolTip` + `Placement="Top"` to fix z-order inside Viewbox overlay
3. ✅ Mic meter boost — `MeterLevel` multiplied by 1.2× before clamping so the bar reads ~20% higher at same input level
4. ✅ Click-to-position sliders — clicking anywhere on the mic/game volume slider track now jumps the thumb to that position before starting the drag
5. ✅ Backdrop visibility — the dedicated `<Image>` now binds `Visibility` to `BackdropVisible` (ViewModel property); compositor checks `IsVisible` before blit
6. ✅ Rename "Backdrop" → "Game Capture" in `EnsureBackdrop()` + test assertions
7. ✅ Elements panel — new "ELEMENTS" section beneath Sources list; per-element config with live preview, ✕ revert, ✓ applied indicator
8. ✅ Webcam border config — color hex input + color swatch picker, border thickness 0–10 slider
9. ✅ Countdown source — `SourceType.Countdown`, pick list (Starting/BRB scenes only), timer minutes 1–60 default 15
10. ✅ Web source — `SourceType.WebSource`, pick list (all scenes), URI text input
11. ✅ Elements scrollbar deselect fix — clicking the Elements panel scrollbar no longer deselects the selected element (scrollbar lives inside the ScrollViewer, not the StackPanel; guard now checks `ElementsScrollViewer` instead of `ElementsPanel`)
12. ✅ Web source URI + buttons inline — merged URI TextBox and check/revert buttons into a single DockPanel row (✓ rightmost, ✕ left); buttons no longer wrap to a separate line
13. ✅ Web source URI hidden for webcam — URI section was showing for webcam due to WPF binding path `SelectedElement.Type` not resolving on `WebcamSceneConfig`; replaced with `IsWebSource` virtual property on `SceneElement` (mirrors existing `IsWebcam` pattern), overridden in `Source` to return `Type == SourceType.WebSource`, bound via `BoolToVis`
14. ✅ Check/revert consistent order + accept — all three element sections (webcam border, countdown timer, web URI) now use consistent [✕][✓] button order; green check buttons enabled with click handlers that save current values as snapshot baseline (so revert undoes to last accepted state, not initial selection)

---

## TASK 15 — Stock scene background images

**Goal:** branded background images for each canonical scene (Starting, Live, BRB, Chat, Ending)
that both provide working hints to creators and self-promote LlamaCasty.

### Status: ✅ Shipped — all 5 scenes seeded

1. ✅ **Starting backdrop** — `Assets/starting-backdrop.jpg` (embedded resource), `SeedStartingBackdrop()` in MainViewModel, idempotent
2. ✅ **BRB backdrop** — `Assets/brb-backdrop.jpg` (user-provided Gemini image), `SeedBrbBackdrop()` in MainViewModel, idempotent
3. ✅ **Live backdrop** — `Assets/live-backdrop.jpg` (user-provided image), seeded via `SeedLiveBackdropAsset()`, used as the static fallback (TASK 16)
4. ✅ **Ending backdrop** — `Assets/ending-backdrop.jpg` (user-provided image), `SeedEndingBackdrop()` replaces existing (not skip-if-exists)
5. ✅ **Chat backdrop** — `Assets/chat-backdrop.jpg` (user-provided image), `SeedChatBackdrop()` at startup
6. ✅ `EnsureDefaultBackdrop()` called on every scene switch — seeds the default backdrop if scene has none

### Design decisions

- Images are user-provided, not generated — the creator owns the brand look
- Each scene gets its own image (Starting = "Starting Soon", Live = live branding, BRB = "Be Right Back", etc.)
- The images double as the no-game backdrop fallback (TASK 16), so the Live scene image should work as a desktop replacement

---

## TASK 16 — Kill infinity display (no-game backdrop fallback)

**Goal:** when no full-screen game is detected, show a static branded placeholder instead of
capturing the primary display (which causes the infinity mirror effect).

### Status: ✅ Shipped

**Changes:**
1. `ResolveAutoCaptureKey()` returns `null` when no full-screen game is detected (was: primary monitor)
2. `ReacquireScreenCaptures()` — clears stale `CaptureKey` when `auto == null` (handles DB upgrades);
   skips `AcquireAsync` when no keys are set
3. `SeedLiveBackdropAsset()` — sets `AssetId` on the backdrop element itself (NOT a Background source);
   called from `ReacquireScreenCaptures()` after `EnsureBackdrop()` guarantees the element exists
4. `Source.DisplaySource` falls back to `_imageSource` when `VideoImageSource` is null for live captures
5. `Assets/live-backdrop.jpg` — user-provided image, added as `<Resource>` in csproj
6. `ResolveOutputFrame()` in compositor — `Source { IsLiveCapture: true, CaptureKey: not null }` already skips null keys; fallback pattern `Source { AssetId: not null }` picks up the static image

**Rendering flow:**
| Scenario | Preview | Compositor |
|---|---|---|
| Game detected | Live capture (opaque, covers static asset on backdrop) | `ScreenCaptureManager.GetLatestFrame` |
| No game | Static image via `DisplaySource` → `_imageSource` on backdrop | `StaticPixelCache.Get(assetId)` |
| Manual capture pick | Live capture | Live frame |

---

## TASK 17 — Web source rendering (WebView2)

**Goal:** make the web source actually render URLs into the preview and stream output.

### Status: ✅ Done — required for v1 (2026-08-28)

1. ✅ Add `Microsoft.Web.WebView2` NuGet package
2. ✅ Schema v10: `WebUri TEXT` column on `Source` table + migration in `LayoutStore.cs`
3. ✅ Persist `Source.WebUri` on save/load (currently in-memory only — lost on restart)
4. ✅ Hidden off-screen `WebView2` control per web source — navigates to `WebUri`, renders in-app
5. ✅ Frame capture from WebView2 (`CoreWebView2.CapturePreviewAsync`) → `WriteableBitmap` (BGRA8)
6. ✅ Wire into `FramePump` resolver — `Source { Type: WebSource }` → latest WebView2 frame
7. ✅ Wire into `SceneCompositor` — render web source as an image element at its position/size
8. ✅ Preview shows live web content (not just a blank rectangle)
9. ☐ Handle navigation errors, invalid URIs, timeout gracefully

**Rendering model (2026-08-28, canvas-size viewport + real-content-bounds crop):**
the page renders at the MASTER CANVAS size (1920×1080), stable, never tracked (no reflow/truncation;
scrollbars suppressed via `overflow:hidden`). After each navigation the manager measures the widget's
ACTUAL visible content rect — union of every visible `body *` `getBoundingClientRect` (excludes the
page's own margins/dead space, includes its top-left offset) — and **crops the capture to that rect**,
anchoring the widget at (0,0). `Stretch="Fill"` maps the frame flush under the box: the selection
box bounds the widget tight on all four sides and is pinned to (0,0) for any widget geometry.
⚠️ `ExecuteScriptAsync` JSON-encodes the returned value — the script must return a real OBJECT (not
`JSON.stringify`, which double-encodes → parse exception → crop silently skipped). Graceful-error
handling (item 9) is a follow-up.

**Properties panel (2026-08-28):** web URI ✓/✕ icon buttons are `IsTabStop="False"` so Tab flows
X→Y→W→H→URI; the ✕ button now clears the URI textbox (was reverting to the pre-accept snapshot).
Slider style gained `IsMoveToPointEnabled="True"` — click-anywhere-on-bar jumps the thumb to the
click (volume sliders keep their manual `SetSliderValueFromClick`, harmless duplication).

### Design decisions

- WebView2 is the only option for Windows — it's pre-installed on Windows 10 20H2+ and Windows 11
- The web source is a standard element — positioned/sized/opacitied like any image source
- Frame capture rate can be lower than video FPS (5-10 fps for web content is fine)
- This enables Streamlabs/StreamElements overlays via web URLs

---

## TASK 18 — Local recording

**Goal:** record the stream output to a local file, with or without simultaneously streaming.

### Status: ☐ Not started — required for v1

1. ☐ Extend `EncoderOptions` with `OutputPath?` and recording mode flags
2. ☐ `FfmpegArgs.Build` gains a local-file branch: MP4/MKV container for file output
3. ☐ Three modes:
   - **Record only** — no RTMP push, just local file (for pre-recorded content)
   - **Stream only** — RTMP push, no local file (current behavior)
   - **Stream + record** — dual output via `-f flv rtmp://... -f mp4 file.mp4`
4. ☐ Recording controls in UI (REC button, file path picker, duration display)
5. ☐ Schema migration for recording preferences (default output path, format)
6. ☐ Branding flash appears in local recordings too (free tier)
7. ☐ Output folder: `%APPDATA%\ytLlive\recordings\` with timestamped filenames

### Design decisions

- FFmpeg supports multiple outputs natively (`-f flv rtmp://... -f mp4 file.mp4`) — no second subprocess needed
- MP4 is the default container (widely compatible); MKV as an option (crash-safe, can be remuxed)
- Record-only mode is useful for pre-recorded content or testing without going live
- The branding flash carries into local recordings (free tier billboard extends to recordings)

---

## v1 execution order

The tasks below are ordered by dependency and risk. Each task builds on the previous.

1. ✅ **TASK 9.4** — Live chat (right panel) — wire `YouTubeChatService.Start()`, parse messages, render in panel. Foundation for chat box source.
2. ✅ **TASK 3.18** — Chat box source — renders chat ON the stream. Depends on TASK 9.4 (same message parsing).
3. ✅ **TASK 10** — Polar billing — license key entry + watermark toggle + Velopack auto-updates (steps 1-7 shipped; Velopack update URL pending).
4. ✅ **TASK 19/23** — Control Surface UX — director's control room: thumbnails above central monitor, transitions (Cut/Fade/Move), edit mode offline only, left panel two-state (layers/props ↔ chat), right panel eliminated. Verified shipped 2026-08-24.
5. **TASK 20** — Hotkeys — global keyboard shortcuts. Steps 1-2 shipped 2026-08-26: F1-F9 defaults + config UI with modifier chords, persistence, conflict detection, unbinding.
5b. ✅ **Broadcast metadata pull-out + launch geometry** — shipped 2026-08-24 (row 29 above). Live-screen "Text" tab → broadcast form, persistence + remote update; window default/minimums bumped (1920×1040 / 1366×768) with size+position restore.
6. **TASK 17** — Web source (WebView2) — enables alert ecosystem.
7. **TASK 18** — Local recording — independent, but pairs with stream.
8. **TASK 21** — Media source — video file playback for non-Live scenes.
9. **TASK 22** — Audio sync offset — small, quality-of-life.
10. ✅ **TASK 15** — Stock bg images — all 5 scenes seeded (Starting, BRB, Live, Chat, Ending). `EnsureDefaultBackdrop()` runs on every scene switch.
11. **TASK 13** — Social media launch kit — after all v1 features ship.

---

## TASK 19 — Scene transitions → MERGED into TASK 19/23 (Control Surface UX)

**Superseded by the Control Surface UX task.** Cut/Fade/Move transitions, thumbnails, edit mode, left panel two-state — all shipped as one cohesive feature. See the Control Surface UX section in `ai.md`.

### Design decisions

- **Cut is free** — instant switch, no blending, zero CPU cost. This is the default.
- **Fade is the minimum expectation** — 300ms crossfade is universal. Every streaming tool ships this.
- **Move is economical** — simple slide animation, no video decoding needed. Good middle ground.
- **Custom is premium** — media/stinger transitions require video playback. Heavy but expected by mid-tier streamers.
- Transitions happen in the compositor, not post-encode. The preview sees the same blend as the live output.

---

## TASK 20 — Hotkeys (keyboard shortcuts)

**Goal:** keyboard shortcuts for scene switching and common actions — the single biggest UX gap.

### Status: ◐ In progress — step 2 shipped 2026-08-26

1. ✅ `GlobalHotkeyManager` service — `Services/GlobalHotkeys.cs`: registers OS-level hotkeys on the window HWND via `RegisterHotKey`/`WM_HOTKEY` (`IHotkeyRegistrar` seam for tests; `RegistrarOverride` mirrors `LayoutPathOverride`). Wired in `MainWindow.OnSourceInitialized`.
2. ✅ Scene switching hotkeys — F1-F5 stage/transition the five canonical scenes.
3. ✅ Common action hotkeys — F6 start/end stream, F7 mute mic, F8 mute desktop audio, F9 TRAX play/pause. Dispatch lives in `MainViewModel.HandleHotkey` and honors command gating.
4. ✅ Hotkey configuration UI — `HotkeyConfigDialog` (XAML Window + `HotkeyConfigViewModel`). Click-to-capture, "Unbind" per row, Reset to Defaults. Conflict detection shows a warning; user must unbind the conflicting action first. Modifier chords supported from day 1 (Ctrl+F10, Alt+Shift+F12, etc.).
5. ✅ Global hotkeys — work even when app is not focused (that is what `RegisterHotKey` gives us)
6. ✅ Conflict detection — warns when a chord is already bound to another action; user must unbind first.
7. ✅ Persistence — `LoadHotkeyBindings()` / `SaveHotkeyBindings()` in `LayoutStore`, stored as `"modifiers+vk"` in Settings table. No schema migration needed.
8. ✅ Test: `GlobalHotkeyTests.WmHotkey_StagesScene_And_TogglesMic_And_RevokesOnClose` — real window + fake registrar, a genuine `WM_HOTKEY` posted through the window's own `HwndSource` hook stages the mapped scene and flips mic mute; close revokes every registration.
9. ✅ Test: `HotkeyConfigTests` — round-trip persistence, display string formatting, storage serialization.

### Design decisions

- **Global hotkeys are mandatory** — streamers are in-game and cannot alt-tab. F1-F5 must work from anywhere.
- **Modifier chords from day 1** — Ctrl+F10, Alt+F1, etc. for Stream Deck support and power users.
- **Conflict = warning, not swap** — user must unbind the conflicting action before reassigning. No surprise reassignments.
- **Unbinding** — every action can be set to "None" (no hotkey). Explicitly unbound actions are absent from the DB.
- **No Stream Deck yet** — bare keyboard first. Stream Deck support (physical devices) is v1.1+.

---

## TASK 21 — Media source (video file playback)

**Goal:** play video files (MP4, MOV, AVI) into scenes — starting soon videos, BRB loops, intro/outro clips.

### Status: ☐ Not started — required for v1

1. ☐ `MediaSourceType` enum: `Video`, `Audio` (audio-only files via media source)
2. ☐ `SourceType.MediaSource` addition to the enum
3. ☐ `MediaSourceModel`: `FilePath`, `IsLooping`, `Volume` (0-1), `PlaybackState`
4. ☐ `VideoFrameSource`: FFmpeg-based video decoder → `VideoFrame` pipeline
5. ☐ Frame capture from video file (decode at native FPS, output BGRA8 frames)
6. ☐ Wire into `FramePump` resolver — `Source { Type: MediaSource }` → latest video frame
7. ☐ Wire into `SceneCompositor` — render media source as an image element at its position/size
8. ☐ Loop control — `IsLooping` property, restart on end
9. ☐ Volume control — per-source volume slider for audio playback
10. ☐ UI: file picker (filtered to video formats), loop toggle, volume slider
11. ☐ Schema migration for media source settings (file path, loop, volume)
12. ☐ Tests: video frame extraction, loop behavior, volume scaling, file validation

### Design decisions

- **FFmpeg handles all formats** — no codec-specific code. FFmpeg already in the project.
- **Audio plays through the desktop channel** — media source audio is captured by the WASAPI loopback (like TRAX/game audio). No separate audio routing needed.
- **This pairs with TRAX** — TRAX is background music, media source is background video. Together they make non-Live scenes (Starting/BRB/Ending) feel polished.
- **Not a full NLE** — no trimming, no multi-track, no effects. Just "play this video in the scene."

---

## TASK 22 — Audio sync offset

**Goal:** per-source audio delay compensation to prevent lip-sync drift from USB mics and capture cards.

### Status: ☐ Not started — required for v1

1. ☐ `AudioSyncOffset` property on AudioSource models (default 0ms, range -500ms to +500ms)
2. ☐ Apply offset in `AudioMixer` — delay or advance audio samples relative to video
3. ☐ UI: offset slider per audio source (or global offset for simplicity)
4. ☐ Persist offset in `LayoutStore` (schema migration)
5. ☐ Tests: offset application, positive/negative delay, boundary values

### Design decisions

- **Global offset first** — one setting for all audio sources. Per-source is v1.1+.
- **Simple slider** — -500ms to +500ms, default 0. No numeric input needed.
- **Visual feedback** — show a "sync OK" indicator when offset is applied.

---

## TASK 23 — Studio mode → MERGED into TASK 19/23 (Control Surface UX)

**Superseded by the Control Surface UX task.** Studio mode is now the entire app's paradigm — the director's control surface with 5 thumbnails + central monitor. See the Control Surface UX section in `ai.md`.

---

## TASK 24 — Toast notifications (in-app, non-blocking)

### Status: ✅ Done (shipped 2026-08-23, branch `task24-notifications`)

Replace blocking MessageBoxes with in-window toasts; promote actionable log-only failures.

### Requirements:
1. Library: **Notification.Wpf 11.0.0** (Platonenkov fork of Federerer/Notifications.Wpf) — MIT, active, targets net8.0-windows. Notice #10 added to `THIRD-PARTY-NOTICES.txt`.
2. Placement: bottom-right above the footer (`NotificationArea x:Name="ToastArea"`, last child of MainWindow's root grid → topmost z-order, `Grid.RowSpan=4`, `Margin="0,0,12,96"`, outside the preview Viewbox), max 4 stacked.
3. Behavior: Info ~4s / Success ~4s / Warning ~8s auto-dismiss; **Error sticky until dismissed**.
4. Styling: dark card tints matching the health-banner language (slate `#3a3b52` info, green `#1d5c38` success, amber `#b8860b` warning, dark-red `#8f1f1f` error); corner radius 8; keep-visible-on-hover.
5. Threading: all Show calls marshal via a Dispatcher captured at construction (encoder/pump events fire off-thread).

### Migrations (MessageBox → toast):
- Webcam acquire failure ×2 (`AddWebcamToStagedSceneAsync`, `SwapWebcamIdentityAsync`) → Warning
- Image read failure (`PickImageBytes`) → Warning
- Sign-in unsuccessful → Warning; sign-in failed → Error

### Promotions (log-only → toast, each keeps its AppLog line):
- Go-live prep ×3: reusable stream unavailable / broadcast insert failed / prep exception → Error
- Frame-pump death while live (`OnFramePumpFailed`) → Error
- Mic missing at startup (`StartMicCaptureAsync`) → Warning (once)
- Premium lapse at startup re-validation → Warning
- Saved-session refresh failure (signed out notice) → Info

Deliberately left alone: offline license re-validation skip (log-only — would spam every launch); SocialsDialog slot-delete YesNo confirm (stays modal).

### Tests:
- Unit: pure severity→request mapping (`NotificationServiceTests`) — area routing, lifetimes, tints.
- Integration (the ONE): real window-hosted `ToastArea` + real service — Info auto-dismisses, Error sticks (`NotificationAreaIntegrationTests`, RealApp collection).

### Library facts (cost a hunt — see also ai.md):
- Area routing matches the area's XAML `Name` against the request's `AreaName`; unknown name silently drops.
- `NeverExpires()` = `ExpirationTime = TimeSpan.MaxValue` (not null); `NotificationColor.ToHex()` returns `#AARRGGBB`.
- Overlay-window shutdown caveat avoided entirely by using the in-window area mode.

---

## TASK 25 — Background consolidation: one locked Background per screen + mini-view rule

### Status: ✅ Done (shipped 2026-08-23, branch `task25-backgrounds`)

The creator rejected the multi-concept background model ("why are there multiple background
things?"). Locked model, verbatim intent:

1. **Exactly ONE background per screen**, named "Background", at position 0.
2. It cannot be re-ordered or deleted; **no Background/Screen item in the (+) menu**.
3. Context-sensitivity exists **only on the Live screen** (Show Desktop toggle + monitor
   switching — behavior kept intact).
4. **Exactly five default background images** live in the DB; stale rows are cleaned up.

### What shipped:
- **Seeder consolidation:** the five near-clone seeders (`Seed{Starting,Brb,Ending,Chat}Background`,
  `SeedLiveBackgroundAsset`, `EnsureDefaultBackground`) are gone. One path now:
  `EnsureBackground(scene)` → `CreateBackground(name)` — Live = `DisplayCapture` row (capture
  machinery untouched), everything else = static `Background` art row; both named "Background".
- **Heal on every load:** `NormalizeBackgrounds(scenes)` keeps the correctly-flavored row,
  converts a wrong-flavor survivor in place (`Source.Type`'s setter derives `IsBackground` —
  conversions must re-assert the flag), drops duplicates, seeds missing ones, renames, pins to
  index 0; non-canonical scenes lose backgrounds + flag. `HealBackgrounds()` stamps default art
  (`Assets/{scene}-background.jpg` via `AddAsset`; custom Browse art wins). This fixed the real DB's
  rot: four scenes carried a stray "Game Capture" duplicate beside their static row, and Settings
  held 16 orphaned `BackgroundUseDefault_{guid}` keys.
- **Settings purge:** `LayoutStore.Save` deletes `BackgroundUseDefault_{id}` / `BackgroundPath_{id}`
  keys whose id is no longer a Source row.
- **(+) menu:** Screen + Background items removed → Webcam/Image/Text/Countdown/Web/YouTube Chat;
  `AddSource` also hard-refuses DisplayCapture/WindowCapture/Background parameters.
- **Capture controls Live-only:** `CanChangeBackground` = staged scene is Live. The preview
  CanvasGrid menu (Show Desktop/Capture Desktop/Refresh Desktop) binds it directly; the layer-row
  context menu MultiBindings it with the row's `IsBackground` through a new
  `Helpers/AllTrueToVisibilityConverter`. Non-Live screens keep the Use-default pill + Browse.
- **Mini rule:** minis never render live captures. While Live is staged its mini shows the green
  placeholder; unstaged it shows `live-background.jpg`. Fixed by making `LoadBackgroundImage`
  flavor-blind (`IsBackground`) and gating staged-Live to the placeholder in `RefreshSnapshotsAsync`.
  (Real-time rendering stays center-monitor-only — preview lag during live gameplay is a known
  unsolved OS-level problem and must not be compounded.)

### Tests (suite went 221/218 → 223/220; the two stale background-policy landmine tests healed here):
- Integration (the ONE): `BackgroundHealIntegrationTests` — seeds a dirty temp DB (duplicate rows,
  misnamed Live row, orphaned keys), drives the real window, asserts one Background per scene at
  index 0 with correct flavor/name, save purges the orphaned keys.
- Unit: SceneCatalogTests rewritten for NormalizeBackgrounds/EnsureBackground flavors;
  BackgroundTests empty-scene flavor updated; SourceNamingTests excludes the always-present
  Background from numbered-name expectations.

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## Backlog (future versions)

1. v1.1 — Stream Deck / Loupedeck integration (requires hotkey foundation from TASK 20)
2. v1.1 — Per-source audio sync offset (global offset ships in TASK 22)
3. v1.1 — Multiple profiles/presets (save different configs for different stream types)
4. v1.1 — Chroma key filter (green screen removal, or ONNX background removal)
5. v1.1 — Virtual camera output (Zoom/Discord/Teams)
6. v1.1 — Replay buffer (instant replay with hotkey)
7. v2 — Multi-destination restreaming (if needed; casual streamers may outgrow LlamaCasty first)
8. v2 — Stream clipping
9. v2 — Export/import settings

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