TASK 7 UI polish batch: scene/source row cleanup, dedup naming, full social handles — scenes are now pure selection rows (edit/trash/visibility icons and inline rename removed with EditSceneCommand/RemoveSceneCommand/ToggleSceneVisibilityCommand + Scene.IsEditing); source rows gained the trio (new EditElementCommand → inline rename via SceneElement.IsEditing, ToggleElementVisibilityCommand → eye flips IsVisible, open/slashed style rebound, hidden rows dim to 45%); duplicate resource names get a no-space incrementing suffix via shared NextSourceName (Image, Image2, Image3…) derived from actual names so deletions never collide (AddSource + AddReusedImage); social bar renders the full validated handle (MaxWidth=200 + TextTrimming removed from SocialBarRenderer and the preview template); side panels stay fixed 220/300; focus-loss capture lag documented in ai.md as a known OS limit (deferred) — the two real-App tests now share RealAppHost, a dedicated STA thread owning the single WPF App, instead of each calling new App(); new SourceNamingTests integration test (Text/Text2/Text3, delete-middle re-add no-collision) — 170 tests passing, 0 warnings

HANDOFF.md

@@ -5,71 +5,81 @@
 > a problem. Conventions: [`schema.md`](schema.md). Rewrite this file at session
 > end, compaction, or any interruption.
 
-## Session state (last updated: 2026-08-12)
+## Session state (last updated: 2026-08-13)
 
-- **Branch:** `main` — the social bar v2 push is **committed + pushed** (`9873eed`,
-  18 files, +1878/−321, 112 tests passing, 0 warnings). Working tree is **dirty
-  with the post-push docs backfill only** (ai.md, README.md, TASKS.md schema
-  section, THIRD-PARTY-NOTICES.txt) — ready to commit when the user says so.
-- **Finished this session (round 3):** user's live-test report said the mastodon
-  icon still didn't show for `@gramps@llamachile.tube`. Root cause: the identity
-  domain `llamachile.tube` is YunoHost-SSO-gated — `/.well-known/nodeinfo`,
-  `/@gramps`, and webfinger all answer with the SSO login page, so nodeinfo
-  returned nothing and the icon fell back to the honeycomb glyph. The real
-  instance lives at `mastodon.llamachile.tube`, and only the bare root
-  `https://llamachile.tube/` 302s to it ("default app" redirect). Fix:
-  `HttpSocialValidator.TryFetchFediverseSoftwareAsync` now, when nodeinfo on the
-  identity domain fails, follows the root redirect (`ResolveInstanceHostAsync`,
-  reads `resp.RequestMessage.RequestUri.Host`) and re-runs the nodeinfo lookup
-  on the resolved host. New test `FediverseHandle_RootRedirectToSubdomain_ResolvesSoftware`.
-  Build: **0 warnings**. Tests: **112 passing**.
-- **What landed (all rounds this session):**
-  1. **Fediverse icon resolution** — `DetectService` maps `@user@domain` to the
-     new `SocialService.Fediverse` (was `Link`/chain icon). On validate,
-     `HttpSocialValidator` best-effort GETs `https://{domain}/.well-known/nodeinfo`,
-     follows the first nodeinfo `links[].href`, reads `software.name`, and returns
-     it in `SocialLookupResult.FediverseSoftware`. `SocialEntry`/`SocialSlotViewModel`
-     carry `FediverseSoftware`; `SocialServiceIcons.LogoDataForFediverse(software)`
-     maps it to a bundled logo (mastodon/peertube/pixelfed/misskey/lemmy/pleroma/
-     firefish — Simple Icons CC0), falling back to the `FediverseIconData`
-     honeycomb glyph for unknown software (GoToSocial/Sharkey/Akkoma aren't in
-     Simple Icons). Nodeinfo failure still validates — the glyph falls back.
-  2. **Redirect resolution (round 3)** — identity domains that 302 their root
-     to the real instance (YunoHost default-app subdomains) resolve software via
-     the root redirect when identity-domain nodeinfo is SSO-blocked.
-  3. **Persistence** — new `SocialEntry.Software TEXT` column via
-     `MigrateSocialEntryTable()` (column-presence pattern, same as the others);
-     saved/loaded alongside Service/Handle/ProfileUrl.
-  4. **Icon colors** — `IconButton` style gains `Foreground="#d0d0d0"`
-     (`Themes/Controls.xaml`); the dialog's trash button overrides
-     `Foreground="#e94560"` (`SocialsDialog.xaml`). All other `IconButton`
-     usages are `Path` content with explicit `Fill`, so unaffected.
+- **Branch:** `main`, in sync with `origin/main`.
+- **This session (TASK 7 — UI polish batch, gramps's 6-point review):**
+  1. **Scenes list cleaned:** the per-row edit/trash/visibility icons and the inline
+     rename TextBox are gone. Scenes are pure selection rows; `IsHidden` stays
+     persisted and still dims a hidden row to 45%. Removed dead surface:
+     `EditSceneCommand`/`RemoveSceneCommand`/`ToggleSceneVisibilityCommand` +
+     `BeginEditScene`/`ToggleSceneVisibility`/`RemoveScene` handlers + `Scene.IsEditing`.
+  2. **Sources list upgraded:** each row now has edit + visibility eye + trash. New
+     `EditElementCommand` (`SceneElement.IsEditing` → inline rename TextBox, Enter/Esc/
+     lost-focus commits) and `ToggleElementVisibilityCommand` (flips `SceneElement.IsVisible`);
+     the eye style now binds `IsVisible` and hidden rows dim to 45%.
+  3. **Duplicate naming:** shared `NextSourceName(scene, baseName)` → `Image`, `Image2`,
+     `Image3`… (no space), next free number derived from actual names so deletions never
+     collide. Used by both `AddSource` and `AddReusedImage`.
+  4. **Social bar:** `MaxWidth=200` + `CharacterEllipsis` removed from BOTH
+     `SocialBarRenderer.cs` and the preview DataTemplate — full validated handle renders.
+  5. **Panels:** left 220 / right 300 fixed widths are deliberate — panels never re-layout
+     on resize; the preview absorbs it. No change.
+  6. **Focus-loss capture lag:** recorded in `ai.md` as a known OS limit (DWM/WGC
+     throttling when unfocused + GPU readback contention + the `_framePending` /
+     `DispatcherPriority.Render` gates). NOT an in-app throttle; deferred by user decision.
+- **Test infra change:** the two real-WPF-App tests (round-clip + new source-naming) now
+  share `RealAppHost` — a dedicated STA thread owning the single `App` — via the `RealApp`
+  serial collection. WPF allows exactly one `Application` per AppDomain; never add a test
+  that calls `new App()` directly again — marshal onto `RealAppHost` instead.
+- **Uncommitted:** `MainWindow.xaml` + `MainWindow.xaml.cs` (rows), `ViewModels/MainViewModel.cs`
+  (commands + naming), `Models/SceneElement.cs` (+`IsEditing`), `Models/Scene.cs` (−`IsEditing`),
+  `Services/Compositor/SocialBarRenderer.cs` (no truncation), `ytLive.Tests/SourceNamingTests.cs`
+  (new), `ytLive.Tests/RealAppCollection.cs` (new), `ytLive.Tests/RoundClipInteractionTests.cs`
+  (now uses the shared host), `TASKS.md` (TASK 7 ✅), `ai.md`, `ViewModels/index.md`, `HANDOFF`.
+- **Verified:** build 0 warnings / 0 errors; **170/170 tests pass** (169 + the naming test).
 - **Landmines:**
-  - `LayoutStore.Socials` is only populated by `Load()` — tests must call
-    `store.Load()` before asserting it.
-  - `DetectService("justaname")` → **Website** with empty handle; only
-    unparseable input or `@user@domain` yields Link/Fediverse.
-  - Dialog sign-in provider is `Func<Task<YouTubeChannel?>>`; test fakes must
-    return `Task.FromResult` (sync-completed) so the fire-and-forget command
-    settles before the next assert.
-  - `SocialBarBottomTop = 1040` literal lives in `MainWindow.xaml.cs` (the VM's
-    `MasterFrameHeight` is private).
-  - `Cancel_AbortsInFlightValidation_WithoutMutatingSlot` relies on the
-    BlockingValidator's gate completing synchronously (no
-    `RunContinuationsAsynchronously`) — the assertions run after
-    `Gate.TrySetResult` returns because the awaited continuation executes inline.
-  - Nodeinfo cancellation test cancels mid-lookup via a counting stub; the
-    post-fetch `ct.IsCancellationRequested` check is what reports `Canceled`.
-  - Round-3 redirect fallback fires only when identity-domain nodeinfo fails;
-    the root follow happens automatically (HttpClient default auto-redirect),
-    and `RequestMessage.RequestUri.Host` is read from the final response.
-- **Next step:** TASK 4 ship step 3 — the encoder + RTMP push (FFmpeg subprocess:
-  frames via stdin, stderr health parsing, FLV mux + push to the cached reusable
-  stream's ingestion URL). Nothing else queued — do not expand the task queue on
-  your own.
+  - Never add another test that constructs `new App()` — use `RealAppHost.Run(...)`.
+  - Never set a local `Canvas.SetTop` on the social bar — a local value permanently
+    overrides `{Binding SocialBarTop}` (the `ClearValue` lesson from 5.5).
+  - `AudioMixer` meter `Push` is unconditional **by design now**: `OnMicSample`/
+    `OnLoopbackSample` compute the level first, then raise the event — a
+    `?.Invoke(meter.Push(...))` short-circuit skipped the meter update when
+    nothing was subscribed (found by `RestartMic_ResetsLevel`, fixed).
+  - `MicConnected` comes from the source `Started` event, raised right after
+    `StartRecording()` succeeds — tests must `MarkStarted()` the fake source
+    before asserting connection state.
+  - The mic dot is red until a resource connects (see contract below) — green
+    only after `Started`, yellow on `Failed`.
+  - Zero mic devices at startup = red dot AND the mixer is never started, so
+    loopback + the game bar can't run either (no capture at all) — acceptable.
+  - The game detector is polled on the UI thread via a 250ms `DispatcherTimer`;
+    `OnGameAudioPollTick` wraps `Poll()` in try/catch + `AppLog`.
+  - 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` +
+    the pump stops), not a crash.
+  - `StopAsync` must stop the encoder (closes stdin) **before** awaiting the pump
+    loop — closing stdin unblocks a write stuck on pipe backpressure; the reverse
+    order deadlocks.
+  - Tests never instantiate `MainViewModel` directly except via a real `MainWindow`
+    on the `RealAppHost` STA thread (round-clip + naming), which never go live.
+  - Sandbox can't reach outbound HTTPS — `HttpSocialValidator` stub-handler tests
+    only, never the real instance.
+- **Mic status contract (creator's rule, verified — do NOT "fix"):** the status dot is
+  **red until a mic resource is actually connected**. `MicStatus` starts `NotConnected`
+  (red); it goes green ONLY when the mixer's `MicConnected` fires, which comes strictly
+  from the mic source's `Started` event raised after `StartRecording()` succeeds. Zero
+  devices at startup → stays red and the mixer is never started; capture failure → yellow.
+- **Next step:** commit + push this TASK 7 batch (one commit). Then the remaining TASK 4
+  requirement is **ship step 7 — one-click go live + private-only enforcement** (honor the
+  dialog's chosen visibility / enforce `privacyStatus = "private"`; also fixes the REC sign's
+  private state — see round-3 note). Also queued: task 21 (logo + About hub), task 22 (voice
+  filters). Nothing else queued — do not expand the task queue on your own. Optional, not
+  queued: rewriting the healed entry's `ProfileUrl` to `https://mastodon.llamachile.tube/@gramps`
+  (user must say the word).
 
 - **Secret/DB/port facts live:** OAuth client id/secret in `Helpers/OAuthCredentials.cs`;
   OAuth session token in `Helpers/TokenStore.cs` (DPAPI → `%APPDATA%\ytLlive\ytLlive.auth`);
-  layout DB `%APPDATA%\ytLlive\ytLlive.db` (schema v8; the new `SocialEntry.Software`
+  layout DB `%APPDATA%\ytLlive\ytLlive.db` (schema v8; `SocialEntry.Software`
   column is a column-presence migration like the others, no version bump); OAuth callback
   `http://localhost:8765/oauth2/callback`; crash log `%APPDATA%\ytLlive\startup.log`.

MainWindow.xaml

@@ -49,21 +49,21 @@
             </DrawingImage.Drawing>
         </DrawingImage>
 
-        <!-- Eye icon: open when visible, slashed when hidden -->
+        <!-- Eye icon: open when visible, slashed when hidden (source rows) -->
         <Style x:Key="EyeIconStyle" TargetType="Path">
             <Setter Property="Data" Value="M12,4.5C7,4.5 2.73,7.61 1,12c1.73,4.39 6,7.5 11,7.5s9.27,-3.11 11,-7.5c-1.73,-4.39 -6,-7.5 -11,-7.5zM12,17c-2.76,0 -5,-2.24 -5,-5s2.24,-5 5,-5 5,2.24 5,5 -2.24,5 -5,5zM12,9c-1.66,0 -3,1.34 -3,3s1.34,3 3,3 3,-1.34 3,-3 -1.34,-3 -3,-3z"/>
             <Style.Triggers>
-                <DataTrigger Binding="{Binding IsHidden}" Value="True">
+                <DataTrigger Binding="{Binding IsVisible}" Value="False">
                     <Setter Property="Data" Value="M12,7c2.76,0 5,2.24 5,5 0,0.65 -0.13,1.26 -0.36,1.83l2.92,2.92c1.51,-1.26 2.7,-2.89 3.43,-4.75 -1.73,-4.39 -6,-7.5 -11,-7.5 -1.4,0 -2.74,0.25 -3.98,0.7l2.16,2.16C10.74,7.13 11.35,7 12,7zM2,4.27l2.28,2.28 0.46,0.46C3.08,8.3 1.78,10.02 1,12c1.73,4.39 6,7.5 11,7.5 1.55,0 3.03,-0.3 4.38,-0.84l0.42,0.42L19.73,22 21,20.73 3.27,3 2,4.27zM7.53,9.8l1.55,1.55c-0.05,0.21 -0.08,0.43 -0.08,0.65 0,1.66 1.34,3 3,3 0.22,0 0.44,-0.03 0.65,-0.08l1.55,1.55c-0.67,0.33 -1.41,0.53 -2.2,0.53 -2.76,0 -5,-2.24 -5,-5 0,-0.79 0.2,-1.53 0.53,-2.2zM11.84,9.02l3.15,3.15 0.02,-0.16c0,-1.66 -1.34,-3 -3,-3l-0.17,0.01z"/>
                 </DataTrigger>
             </Style.Triggers>
         </Style>
 
         <Style x:Key="EyeButton" TargetType="Button" BasedOn="{StaticResource IconButton}">
-            <Setter Property="ToolTip" Value="Hide Scene"/>
+            <Setter Property="ToolTip" Value="Hide Source"/>
             <Style.Triggers>
-                <DataTrigger Binding="{Binding IsHidden}" Value="True">
-                    <Setter Property="ToolTip" Value="Show Scene"/>
+                <DataTrigger Binding="{Binding IsVisible}" Value="False">
+                    <Setter Property="ToolTip" Value="Show Source"/>
                 </DataTrigger>
             </Style.Triggers>
         </Style>
@@ -86,27 +86,32 @@
                     <ColumnDefinition Width="Auto"/>
                 </Grid.ColumnDefinitions>
 
-                <!-- Logo / Brand -->
-                <TextBlock Grid.Column="0" Text="ytLlive"
-                           Foreground="#e94560" FontSize="22" FontWeight="Bold"
-                           VerticalAlignment="Center" Margin="0,0,24,0"/>
+                <!-- Logo / Brand — clicking opens the in-app About overlay -->
+                <Button Grid.Column="0" Background="Transparent" BorderThickness="0" Cursor="Hand"
+                        VerticalAlignment="Center" Margin="0,0,24,0" ToolTip="About ytLlive"
+                        Command="{Binding OpenAboutCommand}">
+                    <Button.Template>
+                        <ControlTemplate TargetType="Button">
+                            <ContentPresenter/>
+                        </ControlTemplate>
+                    </Button.Template>
+                    <TextBlock Text="ytLlive" Foreground="#e94560" FontSize="22" FontWeight="Bold"/>
+                </Button>
 
-                <!-- LIVE badge (center) -->
+                <!-- REC sign (center): dark offline, red live, darker red when private -->
                 <StackPanel Grid.Column="1" Orientation="Horizontal"
-                            HorizontalAlignment="Center" VerticalAlignment="Center"
-                            Visibility="{Binding LiveIndicatorVisible, Converter={StaticResource BoolToVis}}">
-                    <Ellipse Width="12" Height="12" Fill="White" VerticalAlignment="Center"
-                             Opacity="{Binding LivePulseOpacity}"/>
-                    <TextBlock Text="LIVE" Foreground="White" FontSize="16" FontWeight="Bold"
-                               VerticalAlignment="Center" Margin="8,0,0,0"/>
+                            HorizontalAlignment="Center" VerticalAlignment="Center">
+                    <Ellipse Width="12" Height="12" VerticalAlignment="Center"
+                             Fill="{Binding RecDotBrush}" Opacity="{Binding RecDotOpacity}"/>
+                    <TextBlock Text="REC" FontSize="16" FontWeight="Bold"
+                               Foreground="{Binding RecTextBrush}" VerticalAlignment="Center" Margin="8,0,0,0"/>
                     <TextBlock Text="{Binding LiveElapsedText}" Foreground="White" FontSize="14"
-                               FontFamily="Consolas" VerticalAlignment="Center" Margin="14,0,0,0"/>
+                               FontFamily="Consolas" VerticalAlignment="Center" Margin="14,0,0,0"
+                               Visibility="{Binding IsLive, Converter={StaticResource BoolToVis}}"/>
                 </StackPanel>
 
                 <!-- Single three-state action button -->
                 <StackPanel Grid.Column="2" Orientation="Horizontal" VerticalAlignment="Center">
-                    <Button Content="About" Style="{StaticResource YtButtonSecondary}"
-                            Click="AboutButton_Click" Margin="0,0,12,0" VerticalAlignment="Center"/>
                     <Border Width="26" Height="26" CornerRadius="13" Background="#16213e" ClipToBounds="True"
                             Margin="0,0,8,0" VerticalAlignment="Center"
                             ToolTip="{Binding AccountDisplayName}"
@@ -188,64 +193,8 @@
                         <ListBox.ItemTemplate>
                             <DataTemplate>
                                 <Grid Margin="0,2">
-                                    <Grid.ColumnDefinitions>
-                                        <ColumnDefinition Width="*"/>
-                                        <ColumnDefinition Width="Auto"/>
-                                        <ColumnDefinition Width="Auto"/>
-                                        <ColumnDefinition Width="Auto"/>
-                                    </Grid.ColumnDefinitions>
-
-                                    <TextBlock Grid.Column="0" Text="{Binding Name}" VerticalAlignment="Center"
-                                               Padding="4,2" TextTrimming="CharacterEllipsis">
-                                        <TextBlock.Style>
-                                            <Style TargetType="TextBlock">
-                                                <Setter Property="Visibility" Value="Visible"/>
-                                                <Style.Triggers>
-                                                    <DataTrigger Binding="{Binding IsEditing}" Value="True">
-                                                        <Setter Property="Visibility" Value="Collapsed"/>
-                                                    </DataTrigger>
-                                                </Style.Triggers>
-                                            </Style>
-                                        </TextBlock.Style>
-                                    </TextBlock>
-
-                                    <TextBox Grid.Column="0" Text="{Binding Name, UpdateSourceTrigger=PropertyChanged}"
-                                             Background="#0f3460" Foreground="#e0e0e0" BorderThickness="0"
-                                             Padding="4,2" VerticalContentAlignment="Center"
-                                             IsVisibleChanged="SceneNameBox_IsVisibleChanged"
-                                             KeyDown="SceneNameBox_KeyDown" LostFocus="SceneNameBox_LostFocus">
-                                        <TextBox.Style>
-                                            <Style TargetType="TextBox">
-                                                <Setter Property="Visibility" Value="Collapsed"/>
-                                                <Style.Triggers>
-                                                    <DataTrigger Binding="{Binding IsEditing}" Value="True">
-                                                        <Setter Property="Visibility" Value="Visible"/>
-                                                    </DataTrigger>
-                                                </Style.Triggers>
-                                            </Style>
-                                        </TextBox.Style>
-                                    </TextBox>
-
-                                    <Button Grid.Column="1" ToolTip="Edit Scene Name"
-                                            Command="{Binding DataContext.EditSceneCommand, RelativeSource={RelativeSource AncestorType=ListBox}}"
-                                            CommandParameter="{Binding}" Style="{StaticResource IconButton}">
-                                        <Path Data="M3,17.25V21h3.75L17.81,9.94l-3.75,-3.75L3,17.25zM20.71,7.04c0.39,-0.39 0.39,-1.02 0,-1.41l-2.34,-2.34c-0.39,-0.39 -1.02,-0.39 -1.41,0l-1.83,1.83 3.75,3.75 1.83,-1.83z"
-                                              Fill="#d0d0d0" Width="13" Height="13" Stretch="Uniform"/>
-                                    </Button>
-
-                                    <Button Grid.Column="2" Style="{StaticResource EyeButton}"
-                                            Command="{Binding DataContext.ToggleSceneVisibilityCommand, RelativeSource={RelativeSource AncestorType=ListBox}}"
-                                            CommandParameter="{Binding}">
-                                        <Path Style="{StaticResource EyeIconStyle}" Fill="#d0d0d0"
-                                              Width="13" Height="13" Stretch="Uniform"/>
-                                    </Button>
-
-                                    <Button Grid.Column="3" ToolTip="Delete Scene"
-                                            Command="{Binding DataContext.RemoveSceneCommand, RelativeSource={RelativeSource AncestorType=ListBox}}"
-                                            CommandParameter="{Binding}" Style="{StaticResource IconButton}">
-                                        <Path Data="M6,19c0,1.1 0.9,2 2,2h8c1.1,0 2,-0.9 2,-2V7H6v12zM19,4h-3.5l-1,-1h-5l-1,1H5v2h14V4z"
-                                              Fill="#d0d0d0" Width="13" Height="13" Stretch="Uniform"/>
-                                    </Button>
+                                    <TextBlock Text="{Binding Name}" VerticalAlignment="Center"
+                                               Padding="4,2" TextTrimming="CharacterEllipsis"/>
                                 </Grid>
                             </DataTemplate>
                         </ListBox.ItemTemplate>
@@ -282,6 +231,11 @@
                         <Helpers:FocusPreservingListBox.ItemContainerStyle>
                             <Style TargetType="ListBoxItem" BasedOn="{StaticResource YtListBoxItem}">
                                 <Setter Property="HorizontalContentAlignment" Value="Stretch"/>
+                                <Style.Triggers>
+                                    <DataTrigger Binding="{Binding IsVisible}" Value="False">
+                                        <Setter Property="Opacity" Value="0.45"/>
+                                    </DataTrigger>
+                                </Style.Triggers>
                             </Style>
                         </Helpers:FocusPreservingListBox.ItemContainerStyle>
                         <ListBox.ItemTemplate>
@@ -290,6 +244,8 @@
                                     <Grid.ColumnDefinitions>
                                         <ColumnDefinition Width="*"/>
                                         <ColumnDefinition Width="Auto"/>
+                                        <ColumnDefinition Width="Auto"/>
+                                        <ColumnDefinition Width="Auto"/>
                                     </Grid.ColumnDefinitions>
 
                                     <Grid.ContextMenu>
@@ -305,9 +261,51 @@
                                     </Grid.ContextMenu>
 
                                     <TextBlock Grid.Column="0" Text="{Binding Name}" VerticalAlignment="Center"
-                                               Padding="4,2" TextTrimming="CharacterEllipsis"/>
+                                               Padding="4,2" TextTrimming="CharacterEllipsis">
+                                        <TextBlock.Style>
+                                            <Style TargetType="TextBlock">
+                                                <Setter Property="Visibility" Value="Visible"/>
+                                                <Style.Triggers>
+                                                    <DataTrigger Binding="{Binding IsEditing}" Value="True">
+                                                        <Setter Property="Visibility" Value="Collapsed"/>
+                                                    </DataTrigger>
+                                                </Style.Triggers>
+                                            </Style>
+                                        </TextBlock.Style>
+                                    </TextBlock>
 
-                                    <Button Grid.Column="1" ToolTip="Remove Source"
+                                    <TextBox Grid.Column="0" Text="{Binding Name, UpdateSourceTrigger=PropertyChanged}"
+                                             Background="#0f3460" Foreground="#e0e0e0" BorderThickness="0"
+                                             Padding="4,2" VerticalContentAlignment="Center"
+                                             IsVisibleChanged="SourceNameBox_IsVisibleChanged"
+                                             KeyDown="SourceNameBox_KeyDown" LostFocus="SourceNameBox_LostFocus">
+                                        <TextBox.Style>
+                                            <Style TargetType="TextBox">
+                                                <Setter Property="Visibility" Value="Collapsed"/>
+                                                <Style.Triggers>
+                                                    <DataTrigger Binding="{Binding IsEditing}" Value="True">
+                                                        <Setter Property="Visibility" Value="Visible"/>
+                                                    </DataTrigger>
+                                                </Style.Triggers>
+                                            </Style>
+                                        </TextBox.Style>
+                                    </TextBox>
+
+                                    <Button Grid.Column="1" ToolTip="Edit Source Name"
+                                            Command="{Binding DataContext.EditElementCommand, RelativeSource={RelativeSource AncestorType=ListBox}}"
+                                            CommandParameter="{Binding}" Style="{StaticResource IconButton}">
+                                        <Path Data="M3,17.25V21h3.75L17.81,9.94l-3.75,-3.75L3,17.25zM20.71,7.04c0.39,-0.39 0.39,-1.02 0,-1.41l-2.34,-2.34c-0.39,-0.39 -1.02,-0.39 -1.41,0l-1.83,1.83 3.75,3.75 1.83,-1.83z"
+                                              Fill="#d0d0d0" Width="13" Height="13" Stretch="Uniform"/>
+                                    </Button>
+
+                                    <Button Grid.Column="2" Style="{StaticResource EyeButton}"
+                                            Command="{Binding DataContext.ToggleElementVisibilityCommand, RelativeSource={RelativeSource AncestorType=ListBox}}"
+                                            CommandParameter="{Binding}">
+                                        <Path Style="{StaticResource EyeIconStyle}" Fill="#d0d0d0"
+                                              Width="13" Height="13" Stretch="Uniform"/>
+                                    </Button>
+
+                                    <Button Grid.Column="3" ToolTip="Remove Source"
                                             Command="{Binding DataContext.RemoveSourceCommand, RelativeSource={RelativeSource AncestorType=ListBox}}"
                                             CommandParameter="{Binding}" Style="{StaticResource IconButton}"
                                             Visibility="{Binding IsBackdrop, Converter={StaticResource InverseBoolToVis}}">
@@ -654,13 +652,12 @@
 
                                     <!-- Social bar: one centered horizontal row at the top or bottom of
                                          the frame, green glow while enabled. Global resource — never a
-                                         Source, no Sources entry. Dragging snaps to the nearest edge. -->
+                                         Source, no Sources entry. Click toggles top ⇄ bottom. -->
                                     <Grid x:Name="SocialBarElement" Width="1920" Canvas.Top="{Binding SocialBarTop}"
                                           Background="Transparent"
                                           Visibility="{Binding SocialBarVisible, Converter={StaticResource BoolToVis}}"
-                                          PreviewMouseLeftButtonDown="SocialBar_PreviewMouseLeftButtonDown"
-                                          PreviewMouseMove="SocialBar_PreviewMouseMove"
-                                          PreviewMouseLeftButtonUp="SocialBar_PreviewMouseLeftButtonUp">
+                                          MouseLeftButtonDown="SocialBar_MouseLeftButtonDown"
+                                          Cursor="Hand">
                                         <Grid.Effect>
                                             <DropShadowEffect Color="{Binding SocialBarGlowBrush.Color}"
                                                               BlurRadius="18" ShadowDepth="0" Opacity="0.9"/>
@@ -680,9 +677,7 @@
                                                               Stretch="Uniform" VerticalAlignment="Center"/>
                                                         <TextBlock Text="{Binding Handle}" Foreground="White"
                                                                    FontSize="14" VerticalAlignment="Center"
-                                                                   Margin="8,0,0,0"
-                                                                   TextTrimming="CharacterEllipsis"
-                                                                   MaxWidth="200"/>
+                                                                   Margin="8,0,0,0"/>
                                                     </StackPanel>
                                                 </DataTemplate>
                                             </ItemsControl.ItemTemplate>
@@ -745,6 +740,63 @@
                                            Foreground="#a0a0b0" FontSize="11" Margin="0,4,0,0"/>
                             </StackPanel>
                         </Border>
+
+                        <!-- Game audio bar: overlaid at the bottom of the preview
+                             window while a full-screen game is producing sound
+                             (the game audio detector). Monitoring UI only — it
+                             lives in the XAML preview and never reaches the live
+                             output. Desktop audio itself is automatic WASAPI
+                             loopback. -->
+                        <Border HorizontalAlignment="Center" VerticalAlignment="Bottom"
+                                Background="#D9000000" CornerRadius="6" Padding="12,8"
+                                Margin="0,0,0,12"
+                                Visibility="{Binding IsGameAudioBarVisible, Converter={StaticResource BoolToVis}}">
+                            <StackPanel Orientation="Horizontal">
+                                <TextBlock Text="Game Audio Capture" Foreground="#a0a0b0" FontSize="11"
+                                           FontWeight="SemiBold" VerticalAlignment="Center" Margin="0,0,8,0"
+                                           ToolTip="Desktop/game audio via WASAPI loopback (automatic)"/>
+                                <Border Width="288" Height="14" CornerRadius="7" Background="#3a3b52" Margin="0,0,8,0"
+                                        ClipToBounds="True" VerticalAlignment="Center">
+                                    <Grid>
+                                        <Rectangle Width="57" Fill="#4a4520" HorizontalAlignment="Left" Margin="173,0,0,0"
+                                                   VerticalAlignment="Stretch"/>
+                                        <Rectangle Width="58" Fill="#4a2222" HorizontalAlignment="Left" Margin="230,0,0,0"
+                                                   VerticalAlignment="Stretch"/>
+                                        <Border HorizontalAlignment="Left" Width="{Binding GameMeterFillWidth}"
+                                                Background="{Binding GameMeterBrush}" Opacity="0.75"/>
+                                        <Rectangle Width="1" Height="10" Fill="#26000000" VerticalAlignment="Center" HorizontalAlignment="Left" Margin="36,0,0,0"/>
+                                        <Rectangle Width="1" Height="10" Fill="#26000000" VerticalAlignment="Center" HorizontalAlignment="Left" Margin="72,0,0,0"/>
+                                        <Rectangle Width="1" Height="10" Fill="#26000000" VerticalAlignment="Center" HorizontalAlignment="Left" Margin="108,0,0,0"/>
+                                        <Rectangle Width="1" Height="10" Fill="#26000000" VerticalAlignment="Center" HorizontalAlignment="Left" Margin="144,0,0,0"/>
+                                        <Rectangle Width="1" Height="10" Fill="#26000000" VerticalAlignment="Center" HorizontalAlignment="Left" Margin="180,0,0,0"/>
+                                        <Rectangle Width="1" Height="10" Fill="#26000000" VerticalAlignment="Center" HorizontalAlignment="Left" Margin="216,0,0,0"/>
+                                        <Rectangle Width="1" Height="10" Fill="#26000000" VerticalAlignment="Center" HorizontalAlignment="Left" Margin="252,0,0,0"/>
+                                        <Rectangle Width="2" Fill="#00000080" HorizontalAlignment="Left" Margin="173,0,0,0"
+                                                   VerticalAlignment="Stretch"/>
+                                        <Rectangle Width="2" Fill="#00000080" HorizontalAlignment="Left" Margin="230,0,0,0"
+                                                   VerticalAlignment="Stretch"/>
+                                    </Grid>
+                                </Border>
+                                <Grid Width="16" Height="16" Cursor="Hand" Margin="0,0,8,0"
+                                      VerticalAlignment="Center" ToolTip="{Binding GameMuteText}"
+                                      MouseLeftButtonUp="GameSpeaker_MouseLeftButtonUp">
+                                    <Path Fill="#d0d0d0" Stretch="Uniform"
+                                          Data="M3,9v6h4l5,5V4L7,9H3zM16.5,12c0,-1.77 -1,-3.29 -2.5,-4.03v8.05c1.5,-0.73 2.5,-2.25 2.5,-4.02zM14,3.23v2.06c2.89,0.86 5,3.54 5,6.71s-2.11,5.85 -5,6.71v2.06c4.01,-0.91 7,-4.49 7,-8.77s-2.99,-7.86 -7,-8.77z"
+                                          Visibility="{Binding GameMuted, Converter={StaticResource InverseBoolToVis}}"/>
+                                    <Path Fill="#ef4444" Stretch="Uniform"
+                                          Data="M3,9v6h4l5,5V4L7,9H3zM16.5,12c0,-1.77 -1,-3.29 -2.5,-4.03v8.05c1.5,-0.73 2.5,-2.25 2.5,-4.02zM14,3.23v2.06c2.89,0.86 5,3.54 5,6.71s-2.11,5.85 -5,6.71v2.06c4.01,-0.91 7,-4.49 7,-8.77s-2.99,-7.86 -7,-8.77z"
+                                          Visibility="{Binding GameMuted, Converter={StaticResource BoolToVis}}"/>
+                                    <Path Stroke="#ef4444" StrokeThickness="2.5" StrokeEndLineCap="Round" Stretch="Uniform"
+                                          Data="M21,3 L3,21"
+                                          Visibility="{Binding GameMuted, Converter={StaticResource BoolToVis}}"/>
+                                </Grid>
+                                <Slider Width="130" Minimum="0" Maximum="1"
+                                        Value="{Binding GameAudioVolume, Mode=TwoWay}" VerticalAlignment="Center"
+                                        PreviewMouseLeftButtonDown="GameVolumeSlider_PreviewMouseLeftButtonDown"
+                                        PreviewMouseLeftButtonUp="GameVolumeSlider_PreviewMouseLeftButtonUp"
+                                        LostMouseCapture="GameVolumeSlider_LostMouseCapture"/>
+                            </StackPanel>
+                        </Border>
                     </Grid>
                 </Grid>
             </Border>
@@ -800,9 +852,10 @@
 
                 <!-- Line 1: Social controls on the LEFT (under scenes/sources),
                      sound meter + volume control CENTERED beneath the preview panel.
-                     Audio is KISS: desktop/game audio is automatic ("it just is" —
-                     WASAPI loopback at unity, zero UI); the creator's only audio
-                     control is the mic — meter, volume, mute. -->
+                     Audio is KISS: desktop/game audio is automatic (WASAPI loopback
+                     at unity); the mic meter is the creator's only footer audio
+                     control (the game audio bar lives INSIDE the preview window,
+                     overlaid at its bottom edge while a full-screen game is up). -->
                 <Grid Grid.Row="0">
                     <Grid.ColumnDefinitions>
                         <ColumnDefinition Width="220"/>
@@ -825,13 +878,19 @@
                         </Button>
                     </StackPanel>
 
-                    <!-- Meter + volume: centered under the preview panel -->
+                    <!-- Mic meter + volume: centered under the preview panel -->
                     <StackPanel Grid.Column="1" Orientation="Horizontal"
                                 HorizontalAlignment="Center" VerticalAlignment="Center">
-                    <TextBlock Text="MIC" Foreground="#a0a0b0" FontSize="11" FontWeight="SemiBold"
-                               VerticalAlignment="Center" Margin="0,0,8,0" Cursor="Hand"
-                               ToolTip="Choose the microphone (voice source)"
-                               MouseLeftButtonUp="MicLabel_MouseLeftButtonUp"/>
+                    <Button Command="{Binding OpenMicPickerCommand}"
+                            Style="{StaticResource YtButtonSecondary}" Padding="12,4"
+                            FontSize="11" VerticalAlignment="Center" Margin="0,0,8,0"
+                            ToolTip="{Binding MicStatusToolTip}">
+                        <StackPanel Orientation="Horizontal">
+                            <Ellipse Width="8" Height="8" Fill="{Binding MicStatusBrush}"
+                                     Margin="0,0,6,0" VerticalAlignment="Center"/>
+                            <TextBlock Text="MIC"/>
+                        </StackPanel>
+                    </Button>
                     <!-- Sound meter: muted track with a ruler scale, zone tints at
                          the yellow (60%) and red (80%) starts. READ-ONLY realtime
                          level display (fill = live level scaled by volume). -->
@@ -863,6 +922,19 @@
                                        VerticalAlignment="Stretch"/>
                         </Grid>
                     </Border>
+                    <Grid Width="16" Height="16" Cursor="Hand" Margin="0,0,8,0"
+                          VerticalAlignment="Center" ToolTip="{Binding MicMuteText}"
+                          MouseLeftButtonUp="MicSpeaker_MouseLeftButtonUp">
+                        <Path Fill="#d0d0d0" Stretch="Uniform"
+                              Data="M12,14c1.66,0 3,-1.34 3,-3V5c0,-1.66 -1.34,-3 -3,-3S9,3.34 9,5v6C9,12.66 10.34,14 12,14zM17.3,11c0,3 -2.54,5.1 -5.3,5.1S6.7,14 6.7,11H5c0,3.41 2.72,6.23 6,6.72V21h2v-3.28c3.28,-0.49 6,-3.31 6,-6.72H17.3z"
+                              Visibility="{Binding MicMuted, Converter={StaticResource InverseBoolToVis}}"/>
+                        <Path Fill="#ef4444" Stretch="Uniform"
+                              Data="M12,14c1.66,0 3,-1.34 3,-3V5c0,-1.66 -1.34,-3 -3,-3S9,3.34 9,5v6C9,12.66 10.34,14 12,14zM17.3,11c0,3 -2.54,5.1 -5.3,5.1S6.7,14 6.7,11H5c0,3.41 2.72,6.23 6,6.72V21h2v-3.28c3.28,-0.49 6,-3.31 6,-6.72H17.3z"
+                              Visibility="{Binding MicMuted, Converter={StaticResource BoolToVis}}"/>
+                        <Path Stroke="#ef4444" StrokeThickness="2.5" StrokeEndLineCap="Round" Stretch="Uniform"
+                              Data="M21,3 L3,21"
+                              Visibility="{Binding MicMuted, Converter={StaticResource BoolToVis}}"/>
+                    </Grid>
                     <Grid Width="16" Height="16" Cursor="Hand" Margin="0,0,8,0"
                           VerticalAlignment="Center" ToolTip="{Binding MicMuteText}"
                           MouseLeftButtonUp="MicSpeaker_MouseLeftButtonUp">

MainWindow.xaml.cs

@@ -1,7 +1,5 @@
 using System.Collections;
 using System.ComponentModel;
-using System.Diagnostics;
-using System.IO;
 using System.Windows;
 using System.Windows.Controls;
 using System.Windows.Input;
@@ -65,7 +63,7 @@ public partial class MainWindow : Window
             : null;
     }
 
-    private void SceneNameBox_IsVisibleChanged(object sender, DependencyPropertyChangedEventArgs e)
+    private void SourceNameBox_IsVisibleChanged(object sender, DependencyPropertyChangedEventArgs e)
     {
         if (sender is TextBox { IsVisible: true } box)
         {
@@ -83,12 +81,6 @@ public partial class MainWindow : Window
         }
     }
 
-    private void MicLabel_MouseLeftButtonUp(object sender, MouseButtonEventArgs e)
-    {
-        if (sender is FrameworkElement { DataContext: MainViewModel vm })
-            vm.OpenMicPickerCommand.Execute(null);
-    }
-
     private void VolumeSlider_PreviewMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
     {
         if (sender is FrameworkElement { DataContext: MainViewModel vm })
@@ -107,6 +99,24 @@ public partial class MainWindow : Window
             vm.SetVolumeAdjusting(false);
     }
 
+    private void GameVolumeSlider_PreviewMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
+    {
+        if (sender is FrameworkElement { DataContext: MainViewModel vm })
+            vm.SetGameVolumeAdjusting(true);
+    }
+
+    private void GameVolumeSlider_PreviewMouseLeftButtonUp(object sender, MouseButtonEventArgs e)
+    {
+        if (sender is FrameworkElement { DataContext: MainViewModel vm })
+            vm.SetGameVolumeAdjusting(false);
+    }
+
+    private void GameVolumeSlider_LostMouseCapture(object sender, MouseEventArgs e)
+    {
+        if (sender is FrameworkElement { DataContext: MainViewModel vm })
+            vm.SetGameVolumeAdjusting(false);
+    }
+
     private void MicSpeaker_MouseLeftButtonUp(object sender, MouseButtonEventArgs e)
     {
         if (sender is FrameworkElement { DataContext: MainViewModel vm })
@@ -115,6 +125,14 @@ public partial class MainWindow : Window
         }
     }
 
+    private void GameSpeaker_MouseLeftButtonUp(object sender, MouseButtonEventArgs e)
+    {
+        if (sender is FrameworkElement { DataContext: MainViewModel vm })
+        {
+            vm.ToggleGameMuteCommand.Execute(null);
+        }
+    }
+
     private void GearButton_Click(object sender, RoutedEventArgs e)
     {
         if (sender is Button { ContextMenu: { } menu } button)
@@ -125,21 +143,6 @@ public partial class MainWindow : Window
         }
     }
 
-    private void AboutButton_Click(object sender, RoutedEventArgs e)
-    {
-        // LGPL/BSD/MIT notices ship next to the exe; open in the OS text viewer.
-        var path = Path.Combine(AppContext.BaseDirectory, "THIRD-PARTY-NOTICES.txt");
-        if (!File.Exists(path)) return;
-        try
-        {
-            Process.Start(new ProcessStartInfo(path) { UseShellExecute = true });
-        }
-        catch (Exception ex)
-        {
-            AppLog.Write(ex, "About: failed to open THIRD-PARTY-NOTICES.txt");
-        }
-    }
-
     private void AddSourceButton_Click(object sender, RoutedEventArgs e)
     {
         if (sender is Button { ContextMenu: { } menu } button)
@@ -254,41 +257,12 @@ public partial class MainWindow : Window
     private void OpacitySlider_ValueChanged(object sender, RoutedPropertyChangedEventArgs<double> e)
         => OpacityValueText.Text = $"{Math.Round(e.NewValue * 100)}%";
 
-    // ─── Social bar drag: vertical only, snaps to top/bottom on release ───
-    private const double SocialBarBottomTop = 1040;
-    private bool _isDraggingSocialBar;
-    private double _socialBarGrabOffsetY;
-
-    private void SocialBar_PreviewMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
+    // ─── Social bar: click toggles top ⇄ bottom. KISS — the drag variant was
+    // unusable for shaky hands (jitter around the direction deadzone), so the bar
+    // rides on {Binding SocialBarTop} alone and a click flips it. ───
+    private void SocialBar_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
     {
-        var bar = (FrameworkElement)sender;
-        _isDraggingSocialBar = true;
-        var toCanvas = CanvasGrid.TransformToVisual(bar).Inverse;
-        var p = toCanvas.Transform(e.GetPosition(bar));
-        _socialBarGrabOffsetY = p.Y - Canvas.GetTop(bar);
-        bar.CaptureMouse();
-        e.Handled = true;
-    }
-
-    private void SocialBar_PreviewMouseMove(object sender, MouseEventArgs e)
-    {
-        if (!_isDraggingSocialBar) return;
-        var bar = (FrameworkElement)sender;
-        var toCanvas = CanvasGrid.TransformToVisual(bar).Inverse;
-        var p = toCanvas.Transform(e.GetPosition(bar));
-        Canvas.SetTop(bar, Math.Clamp(p.Y - _socialBarGrabOffsetY, 0, SocialBarBottomTop));
-        e.Handled = true;
-    }
-
-    private void SocialBar_PreviewMouseLeftButtonUp(object sender, MouseButtonEventArgs e)
-    {
-        if (!_isDraggingSocialBar) return;
-        var bar = (FrameworkElement)sender;
-        var top = Canvas.GetTop(bar);
-        bar.ReleaseMouseCapture();
-        _isDraggingSocialBar = false;
-        var position = top <= SocialBarBottomTop / 2.0 ? SocialBarPosition.Top : SocialBarPosition.Bottom;
-        _viewModel.SetSocialBarPosition(position);
+        _viewModel.ToggleSocialBarPosition();
         e.Handled = true;
     }
 
@@ -398,24 +372,24 @@ public partial class MainWindow : Window
         return null;
     }
 
-    private void SceneNameBox_KeyDown(object sender, KeyEventArgs e)
+    private void SourceNameBox_KeyDown(object sender, KeyEventArgs e)
     {
         if (e.Key is Key.Enter or Key.Escape)
         {
-            CommitSceneEdit(sender);
+            CommitSourceEdit(sender);
             e.Handled = true;
         }
     }
 
-    private void SceneNameBox_LostFocus(object sender, RoutedEventArgs e)
+    private void SourceNameBox_LostFocus(object sender, RoutedEventArgs e)
     {
-        CommitSceneEdit(sender);
+        CommitSourceEdit(sender);
     }
 
-    private static void CommitSceneEdit(object sender)
+    private static void CommitSourceEdit(object sender)
     {
-        if (sender is FrameworkElement { DataContext: Scene scene })
-            scene.IsEditing = false;
+        if (sender is FrameworkElement { DataContext: SceneElement element })
+            element.IsEditing = false;
     }
 
     // ─── List drag-to-reorder (scenes list + sources list) ───

Models/MicStatus.cs

@@ -0,0 +1,13 @@
+namespace ytLive.Models;
+
+/// <summary>Footer mic indicator state (the dot beside the MIC button):
+/// <see cref="Connected"/> = mic capture is running; <see cref="Problem"/> = a
+/// mic was requested but the connection failed (device in use, unplugged, or
+/// unavailable); <see cref="NotConnected"/> = no capture is active (e.g. no
+/// mic device present).</summary>
+public enum MicStatus
+{
+    NotConnected,
+    Connected,
+    Problem
+}

Models/Scene.cs

@@ -9,7 +9,6 @@ public class Scene : INotifyPropertyChanged
     public string Id { get; init; } = Guid.NewGuid().ToString();
 
     private string _name = string.Empty;
-    private bool _isEditing;
     private bool _isHidden;
     private bool _hasBackdrop;
     private bool _hasSocialBar;
@@ -20,12 +19,6 @@ public class Scene : INotifyPropertyChanged
         set => Set(ref _name, value);
     }
 
-    public bool IsEditing
-    {
-        get => _isEditing;
-        set => Set(ref _isEditing, value);
-    }
-
     public bool IsHidden
     {
         get => _isHidden;

Models/SceneElement.cs

@@ -53,6 +53,9 @@ public abstract class SceneElement : INotifyPropertyChanged
     private bool _isVisible = true;
     public bool IsVisible { get => _isVisible; set => Set(ref _isVisible, value); }
 
+    private bool _isEditing;
+    public bool IsEditing { get => _isEditing; set => Set(ref _isEditing, value); }
+
     private ClipShape _clipShape = ClipShape.Traditional;
     public ClipShape ClipShape
     {

Models/Socials.cs

@@ -19,8 +19,22 @@ public sealed class SocialEntry : INotifyPropertyChanged
     public string Handle { get; init; } = string.Empty;
     public string ProfileUrl { get; init; } = string.Empty;
 
-    /// <summary>Fediverse instance software (nodeinfo) for <see cref="Service"/> = Fediverse.</summary>
-    public string? FediverseSoftware { get; init; }
+    private string? _fediverseSoftware;
+
+    /// <summary>Fediverse instance software (nodeinfo) for <see cref="Service"/> = Fediverse.
+    /// Settable so the load-time heal can fill a missing name and the bar icon
+    /// updates in place.</summary>
+    public string? FediverseSoftware
+    {
+        get => _fediverseSoftware;
+        set
+        {
+            if (_fediverseSoftware == value) return;
+            _fediverseSoftware = value;
+            Raise(nameof(FediverseSoftware));
+            Raise(nameof(LogoData));
+        }
+    }
 
     public string ServiceName => Service.ToString();
     public string LogoData => Service == SocialService.Fediverse
@@ -238,7 +252,7 @@ public static class SocialServiceIcons
     }
 
     /// <summary>True when the input is a fediverse handle (@user@domain); out the parts.</summary>
-    private static bool TryParseFediverse(string input, out string user, out string domain)
+    public static bool TryParseFediverse(string input, out string user, out string domain)
     {
         user = domain = string.Empty;
         if (string.IsNullOrWhiteSpace(input) || input[0] != '@') return false;

Models/index.md

@@ -13,6 +13,7 @@ Plain data types. No logic beyond what a property can carry. See
 | `WebcamSceneConfig.cs` | Per-scene webcam placement (subclass of `SceneElement`): geometry + `IsVisible` + border (`BorderColor`/`BorderOpacity`/`BorderWidth`/`BorderAnimation`) + `VideoImageSource`; `WebcamId` links to `Webcam` |
 | `QualityOption.cs` | Resolution tier record `(Display, Fps, Bitrate, Width, Height)`; `Label` formats as `1080p60 (8Mbps)` — drives the bottom-bar dropdown and the output-rect math |
 | `StreamConfig.cs` | `StreamConfig` (note: `TargetBitrate`/`Resolution` defaults are stale — not yet wired to the dropdown), `StreamHealth` (bitrate/FPS/dropped/duration), `StreamStatus` enum |
+| `MicStatus.cs` | Footer mic indicator: `NotConnected` / `Connected` / `Problem` — the state behind the MIC button's status dot (red = no device/capture off, green = capturing, yellow = a requested mic failed: in use/unplugged) |
 | `YouTube.cs` | `YouTubeChannel` and `ChatMessage` (chat feed) |
 | `Socials.cs` | **Social bar** (global layer, never a Source): `SocialService` enum (YouTube/Twitch/X/Instagram/TikTok/Facebook/Discord/Kick/Threads/Bluesky/GitHub/LinkedIn/Pinterest/Snapchat/Reddit/WhatsApp/Telegram/Link/Website/**Fediverse**), `SocialEntry` (Service/Handle/ProfileUrl/`FediverseSoftware`), `SocialsConfig` (Entries + `BarPosition` Top/Bottom + `BarEnabled` on/off — `BarJustify` dropped, column back-compat), `SocialServiceIcons` (canonical URL builder + `DetectService` (URL domain / fediverse `@user@domain` → **Fediverse** / bare→Website) + bundled SVG logo path data per service (`LogoDataFor`) + `LogoDataForFediverse(software)` mapping nodeinfo software names (mastodon/peertube/pixelfed/misskey/lemmy/pleroma/firefish) to logos with a generic fediverse glyph fallback (`FediverseIconData`) + `LockedIconData`/`DoNotIconData` — initials/colors gone) |
 

Services/Audio/AudioLevelMeter.cs

@@ -0,0 +1,49 @@
+namespace ytLive.Services.Audio;
+
+/// <summary>
+/// Computes the smoothed mic level (0..1) from captured samples. Pure —
+/// unit-tested; the <see cref="AudioMixer"/> only feeds it and forwards the
+/// result. RMS-based so it tracks perceived loudness, smoothed so the meter
+/// does not flicker.
+/// </summary>
+public sealed class AudioLevelMeter
+{
+    private const float Smoothing = 0.2f;
+    private float _level;
+
+    public float Level => _level;
+
+    /// <summary>
+    /// Maps a linear level (0..1) onto the meter's display scale: -60 dBFS..0 dBFS
+    /// spread linearly across 0..1. Linear RMS of real speech or game audio is
+    /// ~0.01..0.1 (-40..-20 dBFS), which leaves a flat (linear) meter looking
+    /// dead; the log scale makes typical levels occupy the bar.
+    /// </summary>
+    public static float ToDisplay(float linear)
+    {
+        if (linear <= 0.001f)
+            return 0f;
+        var db = 20f * MathF.Log10(linear);
+        return Math.Clamp(1f + db / 60f, 0f, 1f);
+    }
+
+    public float Push(AudioSample sample)
+    {
+        if (sample.Samples.Length == 0)
+            return _level;
+
+        double sumSquares = 0;
+        var count = 0;
+        foreach (var value in sample.Samples)
+        {
+            sumSquares += value * value;
+            count++;
+        }
+
+        var rms = (float)Math.Sqrt(sumSquares / count);
+        _level = _level * (1 - Smoothing) + rms * Smoothing;
+        return _level;
+    }
+
+    public void Reset() => _level = 0;
+}

Services/Audio/AudioMixer.cs

@@ -0,0 +1,133 @@
+using ytLive.Services;
+
+namespace ytLive.Services.Audio;
+
+/// <summary>
+/// Owns the mic + desktop/game capture sources (TASK 4 ship step 4) and drives
+/// the footer meters. Capture runs for the app's lifetime (started once at
+/// startup, stopped on shutdown) so both bars stay live in preview: mic samples
+/// are level-metered and forwarded, loopback samples feed the game bar's meter.
+/// The mixer surfaces mic connection state (Connected/Failed) for the status
+/// dot and can restart the mic source mid-session when a device is re-picked.
+/// </summary>
+public sealed class AudioMixer : IDisposable
+{
+    private readonly IAudioSource _mic;
+    private readonly IAudioSource _loopback;
+    private readonly AudioLevelMeter _meter;
+    private readonly AudioLevelMeter _loopbackMeter;
+    private readonly Action<string>? _log;
+    private bool _started;
+
+    public AudioMixer(IAudioSource mic, IAudioSource loopback, Action<string>? log = null)
+    {
+        _mic = mic;
+        _loopback = loopback;
+        _meter = new AudioLevelMeter();
+        _loopbackMeter = new AudioLevelMeter();
+        _log = log;
+
+        _mic.Started += OnMicStarted;
+        _mic.SampleReady += OnMicSample;
+        _loopback.SampleReady += OnLoopbackSample;
+        _mic.Failed += OnMicFailed;
+        _loopback.Failed += OnLoopbackFailed;
+    }
+
+    /// <summary>Current smoothed mic level (0..1).</summary>
+    public float MicLevel => _meter.Level;
+
+    /// <summary>Current smoothed desktop/game level (0..1).</summary>
+    public float LoopbackLevel => _loopbackMeter.Level;
+
+    /// <summary>Raised whenever the smoothed mic level changes.</summary>
+    public event Action<float>? MicLevelChanged;
+
+    /// <summary>Raised whenever the smoothed desktop/game level changes.</summary>
+    public event Action<float>? LoopbackLevelChanged;
+
+    /// <summary>Raised when the mic capture comes up (the status dot goes green).</summary>
+    public event Action? MicConnected;
+
+    /// <summary>Raised when the mic capture fails or dies (the status dot goes yellow).</summary>
+    public event Action<Exception>? MicFailed;
+
+    public void Start()
+    {
+        if (_started)
+            return;
+
+        _started = true;
+        _meter.Reset();
+        _loopback.Start();
+        _mic.Start();
+    }
+
+    /// <summary>Swaps the mic source without touching loopback — used when the
+    /// creator picks a different device mid-session. The level resets and the
+    /// new source raises <see cref="MicConnected"/> or <see cref="MicFailed"/>.</summary>
+    public void RestartMic()
+    {
+        _mic.Stop();
+        _meter.Reset();
+        MicLevelChanged?.Invoke(0);
+        _mic.Start();
+    }
+
+    public void Stop()
+    {
+        if (!_started)
+            return;
+
+        _started = false;
+        _mic.Stop();
+        _loopback.Stop();
+        _meter.Reset();
+        _loopbackMeter.Reset();
+        MicLevelChanged?.Invoke(0);
+        LoopbackLevelChanged?.Invoke(0);
+    }
+
+    public void Dispose()
+    {
+        Stop();
+        _mic.Started -= OnMicStarted;
+        _mic.SampleReady -= OnMicSample;
+        _loopback.SampleReady -= OnLoopbackSample;
+        _mic.Failed -= OnMicFailed;
+        _loopback.Failed -= OnLoopbackFailed;
+        _mic.Dispose();
+        _loopback.Dispose();
+    }
+
+    private void OnMicStarted()
+    {
+        MicConnected?.Invoke();
+    }
+
+    private void OnMicSample(AudioSample sample)
+    {
+        // Push unconditionally: the ?. on the event would otherwise skip the
+        // argument (and the meter update) when nothing is subscribed yet.
+        var level = _meter.Push(sample);
+        MicLevelChanged?.Invoke(level);
+    }
+
+    private void OnLoopbackSample(AudioSample sample)
+    {
+        var level = _loopbackMeter.Push(sample);
+        LoopbackLevelChanged?.Invoke(level);
+    }
+
+    private void OnMicFailed(Exception ex)
+    {
+        _log?.Invoke($"Mic capture failed: {ex.Message}");
+        MicLevelChanged?.Invoke(0);
+        MicFailed?.Invoke(ex);
+    }
+
+    private void OnLoopbackFailed(Exception ex)
+    {
+        _log?.Invoke($"Desktop audio capture failed: {ex.Message}");
+    }
+}

Services/Audio/AudioSample.cs

@@ -0,0 +1,20 @@
+namespace ytLive.Services.Audio;
+
+/// <summary>
+/// A chunk of interleaved PCM float samples (-1..1) with its format. This is
+/// the unit every <see cref="IAudioSource"/> produces and the
+/// <see cref="AudioMixer"/> consumes (TASK 4 ship step 4).
+/// </summary>
+public sealed class AudioSample
+{
+    public float[] Samples { get; }
+    public int SampleRate { get; }
+    public int Channels { get; }
+
+    public AudioSample(float[] samples, int sampleRate, int channels)
+    {
+        Samples = samples;
+        SampleRate = sampleRate;
+        Channels = channels;
+    }
+}

Services/Audio/IAudioSource.cs

@@ -0,0 +1,27 @@
+namespace ytLive.Services.Audio;
+
+/// <summary>
+/// A live audio capture source (TASK 4 ship step 4 seam): produces PCM float
+/// chunks. The default implementations wrap NAudio's WASAPI capture (mic) /
+/// loopback (desktop/game); the mixer and the tests consume this interface,
+/// never NAudio directly. Capture now runs for the app's lifetime so the
+/// footer meters stay live in preview — the mixer owns start/stop.
+/// </summary>
+public interface IAudioSource : IDisposable
+{
+    /// <summary>Starts capturing. Safe to call only once per Stop.</summary>
+    void Start();
+
+    /// <summary>Stops capturing; a later Start begins a fresh session.</summary>
+    void Stop();
+
+    /// <summary>Raises once capture is live (right after recording starts).
+    /// Never raised when Start fails — <see cref="Failed"/> fires instead.</summary>
+    event Action? Started;
+
+    /// <summary>Raises each captured chunk (interleaved PCM float, -1..1).</summary>
+    event Action<AudioSample>? SampleReady;
+
+    /// <summary>Raises when capture dies or fails to start (e.g. no device).</summary>
+    event Action<Exception>? Failed;
+}

Services/Audio/WasapiLoopbackAudioSource.cs

@@ -0,0 +1,72 @@
+using NAudio.Wave;
+
+namespace ytLive.Services.Audio;
+
+/// <summary>
+/// Captures the user's desktop/game audio (TASK 4 ship step 4) via WASAPI
+/// loopback on the default render device. Runs for the app's lifetime so the
+/// game audio bar stays live in preview.
+/// </summary>
+public sealed class WasapiLoopbackAudioSource : IAudioSource
+{
+    private WasapiLoopbackCapture? _capture;
+
+    public event Action? Started;
+    public event Action<AudioSample>? SampleReady;
+    public event Action<Exception>? Failed;
+
+    public void Start()
+    {
+        if (_capture != null)
+            throw new InvalidOperationException("Already started.");
+
+        try
+        {
+            _capture = new WasapiLoopbackCapture();
+            _capture.DataAvailable += OnDataAvailable;
+            _capture.RecordingStopped += OnRecordingStopped;
+            _capture.StartRecording();
+            Started?.Invoke();
+        }
+        catch (Exception ex)
+        {
+            Stop();
+            Failed?.Invoke(ex);
+        }
+    }
+
+    public void Stop()
+    {
+        if (_capture == null)
+            return;
+
+        try
+        {
+            _capture.StopRecording();
+        }
+        catch
+        {
+        }
+        _capture.Dispose();
+        _capture = null;
+    }
+
+    public void Dispose() => Stop();
+
+    private void OnDataAvailable(object? sender, WaveInEventArgs e)
+    {
+        if (e.BytesRecorded <= 0)
+            return;
+
+        var format = _capture?.WaveFormat ?? WaveFormat.CreateIeeeFloatWaveFormat(48000, 2);
+        var samples = WaveToFloat.Convert(e.Buffer, e.BytesRecorded, format);
+        if (samples.Length > 0)
+            SampleReady?.Invoke(new AudioSample(samples, format.SampleRate, format.Channels));
+    }
+
+    private void OnRecordingStopped(object? sender, StoppedEventArgs e)
+    {
+        if (e.Exception != null)
+            Failed?.Invoke(e.Exception);
+    }
+}

Services/Audio/WasapiMicAudioSource.cs

@@ -0,0 +1,105 @@
+using NAudio.CoreAudioApi;
+using NAudio.Wave;
+
+namespace ytLive.Services.Audio;
+
+/// <summary>
+/// Captures the selected microphone (TASK 4 ship step 4) via WASAPI. Resolves
+/// the NAudio device by FriendlyName matching <c>MicSourceName</c> (the app only
+/// persists DisplayName), falling back to the default capture endpoint.
+/// </summary>
+public sealed class WasapiMicAudioSource : IAudioSource
+{
+    private readonly Func<string?> _micNameProvider;
+    private WasapiCapture? _capture;
+
+    /// <param name="micNameProvider">Returns the current mic DisplayName; read
+    /// at each Start so a device picked mid-session takes effect immediately
+    /// (the mixer restarts the mic on pick).</param>
+    public WasapiMicAudioSource(Func<string?> micNameProvider)
+    {
+        _micNameProvider = micNameProvider;
+    }
+
+    public event Action? Started;
+    public event Action<AudioSample>? SampleReady;
+    public event Action<Exception>? Failed;
+
+    public void Start()
+    {
+        if (_capture != null)
+            throw new InvalidOperationException("Already started.");
+
+        try
+        {
+            var device = ResolveDevice();
+            _capture = device != null ? new WasapiCapture(device) : new WasapiCapture();
+            _capture.DataAvailable += OnDataAvailable;
+            _capture.RecordingStopped += OnRecordingStopped;
+            _capture.StartRecording();
+            Started?.Invoke();
+        }
+        catch (Exception ex)
+        {
+            Stop();
+            Failed?.Invoke(ex);
+        }
+    }
+
+    public void Stop()
+    {
+        if (_capture == null)
+            return;
+
+        try
+        {
+            _capture.StopRecording();
+        }
+        catch
+        {
+        }
+        _capture.Dispose();
+        _capture = null;
+    }
+
+    public void Dispose() => Stop();
+
+    private MMDevice? ResolveDevice()
+    {
+        var micName = _micNameProvider();
+        if (string.IsNullOrWhiteSpace(micName))
+            return null;
+
+        try
+        {
+            using var enumerator = new MMDeviceEnumerator();
+            foreach (var endpoint in enumerator.EnumerateAudioEndPoints(DataFlow.Capture, DeviceState.Active))
+            {
+                if (string.Equals(endpoint.FriendlyName, micName, StringComparison.OrdinalIgnoreCase))
+                    return endpoint;
+            }
+        }
+        catch
+        {
+        }
+
+        return null;
+    }
+
+    private void OnDataAvailable(object? sender, WaveInEventArgs e)
+    {
+        if (e.BytesRecorded <= 0)
+            return;
+
+        var format = _capture?.WaveFormat ?? WaveFormat.CreateIeeeFloatWaveFormat(48000, 1);
+        var samples = WaveToFloat.Convert(e.Buffer, e.BytesRecorded, format);
+        if (samples.Length > 0)
+            SampleReady?.Invoke(new AudioSample(samples, format.SampleRate, format.Channels));
+    }
+
+    private void OnRecordingStopped(object? sender, StoppedEventArgs e)
+    {
+        if (e.Exception != null)
+            Failed?.Invoke(e.Exception);
+    }
+}

Services/Audio/WaveToFloat.cs

@@ -0,0 +1,41 @@
+using NAudio.Dmo;
+using NAudio.Wave;
+
+namespace ytLive.Services.Audio;
+
+/// <summary>
+/// Converts NAudio's raw WASAPI capture buffers (byte[], whatever bit depth the
+/// device's mix format reports) into interleaved PCM float samples. Pure —
+/// unit-tested; the two WASAPI sources share it.
+/// </summary>
+public static class WaveToFloat
+{
+    public static float[] Convert(byte[] buffer, int bytesRecorded, WaveFormat format)
+    {
+        if (format.Encoding == WaveFormatEncoding.IeeeFloat && format.BitsPerSample == 32)
+            return ConvertIeeeFloat(buffer, bytesRecorded);
+        if (format.Encoding == WaveFormatEncoding.Pcm && format.BitsPerSample == 16)
+            return ConvertPcm16(buffer, bytesRecorded);
+        if (format is WaveFormatExtensible extensible
+            && extensible.SubFormat == AudioMediaSubtypes.MEDIASUBTYPE_IEEE_FLOAT)
+            return ConvertIeeeFloat(buffer, bytesRecorded);
+        return ConvertPcm16(buffer, bytesRecorded);
+    }
+
+    private static float[] ConvertIeeeFloat(byte[] buffer, int bytesRecorded)
+    {
+        var count = bytesRecorded / 4;
+        var result = new float[count];
+        Buffer.BlockCopy(buffer, 0, result, 0, count * 4);
+        return result;
+    }
+
+    private static float[] ConvertPcm16(byte[] buffer, int bytesRecorded)
+    {
+        var count = bytesRecorded / 2;
+        var result = new float[count];
+        for (var i = 0; i < count; i++)
+            result[i] = BitConverter.ToInt16(buffer, i * 2) / 32768f;
+        return result;
+    }
+}

Services/Compositor/SceneCompositor.cs

@@ -18,13 +18,16 @@ public sealed class SceneCompositor
     /// Composite <paramref name="scene"/> into the tier's output frame. Layer order (back →
     /// front): live backdrop (the scene's <c>IsBackdrop</c> source) → background image →
     /// visible elements (z-order = <c>Elements</c> order, mirroring the XAML DataTemplate) →
-    /// branding flash. Transparent regions read opaque black.
+    /// branding flash → social bar (a global overlay; spans the master width at
+    /// <paramref name="socialBarTop"/>). Transparent regions read opaque black.
     /// </summary>
     public VideoFrame Render(
         Scene scene,
         Func<SceneElement, VideoFrame?> frameFor,
         VideoFrame? flashFrame,
-        CompositorOptions options)
+        CompositorOptions options,
+        VideoFrame? socialBarFrame = null,
+        int socialBarTop = 0)
     {
         if (scene == null) throw new ArgumentNullException(nameof(scene));
         if (frameFor == null) throw new ArgumentNullException(nameof(frameFor));
@@ -79,7 +82,10 @@ public sealed class SceneCompositor
         }
 
         if (flashFrame != null)
-            BlitFlash(buffer, cropW, cropH, options, flashFrame);
+            BlitOverlay(buffer, cropW, cropH, options, flashFrame, 0, 0);
+
+        if (socialBarFrame != null && socialBarFrame.Width > 0 && socialBarFrame.Height > 0)
+            BlitOverlay(buffer, cropW, cropH, options, socialBarFrame, 0, socialBarTop);
 
         return StretchMath.BilinearScale(
             new VideoFrame(cropW, cropH, buffer), options.OutputWidth, options.OutputHeight);
@@ -166,17 +172,20 @@ public sealed class SceneCompositor
         }
     }
 
-    /// <summary>1:1 copy of the master-sized branding flash, cropped to the active source rect.</summary>
-    private static void BlitFlash(byte[] dst, int dstW, int dstH, CompositorOptions options, VideoFrame flash)
+    /// <summary>1:1 copy of a master-sized overlay (flash, social bar) cropped to the
+    /// active source rect. The overlay is positioned in master space by (sx0, sy0).</summary>
+    private static void BlitOverlay(
+        byte[] dst, int dstW, int dstH, CompositorOptions options,
+        VideoFrame overlay, int sx0, int sy0)
     {
         for (var y = 0; y < dstH; y++)
         {
             for (var x = 0; x < dstW; x++)
             {
-                var sx = x + options.SourceRectX;
-                var sy = y + options.SourceRectY;
-                if (sx >= flash.Width || sy >= flash.Height) continue;
-                var sample = StretchMath.SampleBgra(flash.BgraPixels, flash.Width, flash.Height, sx, sy);
+                var sx = x + options.SourceRectX - sx0;
+                var sy = y + options.SourceRectY - sy0;
+                if (sx < 0 || sy < 0 || sx >= overlay.Width || sy >= overlay.Height) continue;
+                var sample = StretchMath.SampleBgra(overlay.BgraPixels, overlay.Width, overlay.Height, sx, sy);
                 BlendPixel(dst, (y * dstW + x) * 4, sample, 1f);
             }
         }

Services/Compositor/SocialBarRenderer.cs

@@ -0,0 +1,105 @@
+using System.Collections.Generic;
+using System.Linq;
+using System.Windows;
+using System.Windows.Controls;
+using System.Windows.Media;
+using System.Windows.Media.Effects;
+using System.Windows.Media.Imaging;
+using System.Windows.Shapes;
+using ytLive.Models;
+
+namespace ytLive.Services.Compositor;
+
+/// <summary>
+/// Rasterizes the global social bar into a transparent BGRA8 strip the output
+/// compositor overlays onto the master frame (top or bottom edge). Replicates the
+/// preview's bar DataTemplate in code — one Path (logo) + one TextBlock (handle)
+/// per entry, white on transparent, green glow — then software-renders it via
+/// <c>RenderTargetBitmap</c> and converts Pbgra32 (premultiplied) to straight-alpha
+/// BGRA for the compositor. WPF glue like <see cref="StaticPixelCache"/>: the
+/// compositor core itself stays pure byte-math. Renders on the UI thread only;
+/// the returned frame is immutable afterwards, so the frame pump may read it from
+/// any thread.
+/// </summary>
+public static class SocialBarRenderer
+{
+    /// <summary>Icon size + the preview's 8px top/bottom margins.</summary>
+    private const int ContentHeight = 40;
+
+    /// <summary>Room for the green DropShadowEffect blur to bleed past the content.</summary>
+    private const int GlowPad = 24;
+
+    /// <summary>Master-frame width — the bar spans the full 1920px output.</summary>
+    public const int Width = 1920;
+
+    /// <summary>Returns the strip frame, or null when there is nothing to render.</summary>
+    public static VideoFrame? Render(IEnumerable<SocialEntry>? entries)
+    {
+        var list = entries?.Where(e => e != null).ToList();
+        if (list == null || list.Count == 0) return null;
+
+        var height = ContentHeight + GlowPad * 2;
+
+        var row = new StackPanel { Orientation = Orientation.Horizontal };
+        foreach (var entry in list)
+        {
+            var item = new StackPanel
+            {
+                Orientation = Orientation.Horizontal,
+                Margin = new Thickness(0, 0, 20, 0),
+            };
+            item.Children.Add(new Path
+            {
+                Data = Geometry.Parse(entry.LogoData),
+                Fill = Brushes.White,
+                Width = 24,
+                Height = 24,
+                Stretch = Stretch.Uniform,
+                VerticalAlignment = VerticalAlignment.Center,
+            });
+            item.Children.Add(new TextBlock
+            {
+                Text = entry.Handle,
+                Foreground = Brushes.White,
+                FontSize = 14,
+                VerticalAlignment = VerticalAlignment.Center,
+                Margin = new Thickness(8, 0, 0, 0),
+            });
+            row.Children.Add(item);
+        }
+
+        // The glow is baked in so the output bar matches the preview's green halo.
+        var container = new Grid
+        {
+            Width = Width,
+            Height = height,
+            Background = Brushes.Transparent,
+            Effect = new DropShadowEffect { Color = Color.FromRgb(0x2e, 0xcc, 0x71), BlurRadius = 18, ShadowDepth = 0, Opacity = 0.9 },
+        };
+        var centered = new Grid { HorizontalAlignment = HorizontalAlignment.Center, Margin = new Thickness(0, GlowPad, 0, 0) };
+        centered.Children.Add(row);
+        container.Children.Add(centered);
+
+        container.Measure(new Size(Width, height));
+        container.Arrange(new Rect(0, 0, Width, height));
+
+        var bitmap = new RenderTargetBitmap(Width, height, 96, 96, PixelFormats.Pbgra32);
+        bitmap.Render(container);
+
+        var pixels = new byte[Width * height * 4];
+        bitmap.CopyPixels(pixels, Width * 4, 0);
+
+        // Pbgra32 is premultiplied — unpremultiply so the compositor's straight-alpha
+        // source-over blend doesn't darken the logo edges with a halo.
+        for (var i = 0; i < pixels.Length; i += 4)
+        {
+            var a = pixels[i + 3];
+            if (a == 0 || a == 255) continue;
+            pixels[i] = (byte)(pixels[i] * 255 / a);
+            pixels[i + 1] = (byte)(pixels[i + 1] * 255 / a);
+            pixels[i + 2] = (byte)(pixels[i + 2] * 255 / a);
+        }
+
+        return new VideoFrame(Width, height, pixels);
+    }
+}

Services/Encoder/EncoderOptions.cs

@@ -0,0 +1,27 @@
+namespace ytLive.Services.Encoder;
+
+/// <summary>
+/// Everything the FFmpeg subprocess encoder needs for one go-live (TASK 4 ship
+/// step 3). <see cref="RtmpUrl"/> is the FULL ingestion URL — the reusable
+/// stream's ingest address plus its stream key (<c>rtmp://a.rtmp.youtube.com/live2/&lt;key&gt;</c>).
+/// Resolution/FPS/bitrate come from the active quality tier; audio is a silent
+/// placeholder track until the WASAPI capture step replaces the input.
+/// </summary>
+public sealed class EncoderOptions
+{
+    public string RtmpUrl { get; init; } = string.Empty;
+    public int Width { get; init; } = 1920;
+    public int Height { get; init; } = 1080;
+    public int Fps { get; init; } = 60;
+    public int BitrateKbps { get; init; } = 8000;
+
+    /// <summary>H.264 encoder name for <c>-c:v</c>; the encoder probes and prefers
+    /// nvenc → qsv → amf → libopenh264 when not forced.</summary>
+    public string? VideoEncoder { get; init; }
+
+    public int AudioSampleRate { get; init; } = 48000;
+    public int AudioChannels { get; init; } = 2;
+
+    /// <summary>GOP in frames = Fps × 4s — the YouTube keyframe ≤ 4s compliance bound.</summary>
+    public int GopSize => Fps * 4;
+}

Services/Encoder/FfmpegArgs.cs

@@ -0,0 +1,46 @@
+namespace ytLive.Services.Encoder;
+
+/// <summary>
+/// Builds the FFmpeg command line for a live RTMP push (TASK 4 ship step 3):
+/// raw BGRA frames via stdin (paced <c>-re</c>), silent placeholder audio via lavfi
+/// <c>anullsrc</c> (the WASAPI step replaces this input), H.264 + AAC encoding, FLV
+/// muxing to the ingestion URL. Pure — the encoder just starts
+/// <c>ffmpeg.exe [Build(...)]</c>.
+/// </summary>
+public static class FfmpegArgs
+{
+    public static IReadOnlyList<string> Build(EncoderOptions options, string videoEncoder)
+    {
+        var gop = options.GopSize;
+        return
+        [
+            "-hide_banner",
+            "-loglevel", "info",
+            "-stats",
+            "-stats_period", "0.5",
+            "-re",
+            "-f", "rawvideo",
+            "-pix_fmt", "bgra",
+            "-video_size", $"{options.Width}x{options.Height}",
+            "-framerate", options.Fps.ToString(),
+            "-i", "pipe:0",
+            "-f", "lavfi",
+            "-i", $"anullsrc=channel_layout=stereo:sample_rate={options.AudioSampleRate}",
+            "-c:v", videoEncoder,
+            "-b:v", $"{options.BitrateKbps}k",
+            "-maxrate", $"{options.BitrateKbps}k",
+            "-bufsize", $"{options.BitrateKbps * 2}k",
+            "-g", gop.ToString(),
+            "-keyint_min", gop.ToString(),
+            "-sc_threshold", "0",
+            "-bf", "0",
+            "-pix_fmt", "yuv420p",
+            "-c:a", "aac",
+            "-b:a", "128k",
+            "-ar", options.AudioSampleRate.ToString(),
+            "-ac", options.AudioChannels.ToString(),
+            "-f", "flv",
+            options.RtmpUrl,
+        ];
+    }
+}

Services/Encoder/FfmpegEncoder.cs

@@ -0,0 +1,263 @@
+using System.Diagnostics;
+using ytLive.Helpers;
+using ytLive.Models;
+
+namespace ytLive.Services.Encoder;
+
+/// <summary>
+/// The default <see cref="IFfmpegEncoder"/>: spawns <c>ffmpeg.exe</c> (resolved via
+/// <see cref="IFfmpegLocator"/>), feeds raw BGRA frames into stdin, and parses the
+/// <c>-stats</c> progress lines into <see cref="StreamHealth"/>. Encoder choice is
+/// probed from the binary's <c>-encoders</c> listing (hardware NVENC/QSV/AMF first,
+/// OpenH264 software fallback — never libx264, see the license posture) unless
+/// <see cref="EncoderOptions.VideoEncoder"/> forces one.
+///
+/// Graceful stop = close stdin (EOF) → ffmpeg finalizes the FLV and exits by itself;
+/// a watchdogs kill fires only if it hasn't exited shortly after EOF.
+/// </summary>
+public sealed class FfmpegEncoder : IFfmpegEncoder
+{
+    public event EventHandler<StreamHealth>? HealthUpdated;
+    public event EventHandler<string>? ProcessFailed;
+
+    private readonly IFfmpegLocator _locator;
+    private readonly Func<IEncoderProcess> _processFactory;
+
+    private readonly object _gate = new();
+    private IEncoderProcess? _process;
+    private EncoderOptions? _options;
+    private StreamHealth _health = new() { Status = StreamStatus.Offline };
+    private Task? _stderrLoop;
+    private bool _stopRequested;
+
+    public FfmpegEncoder(
+        IFfmpegLocator locator,
+        Func<IEncoderProcess>? processFactory = null)
+    {
+        _locator = locator;
+        _processFactory = processFactory ?? (() => new FfmpegEncoderProcess());
+    }
+
+    public bool IsRunning { get; private set; }
+
+    public async Task StartAsync(EncoderOptions options, CancellationToken cancellationToken = default)
+    {
+        if (options == null) throw new ArgumentNullException(nameof(options));
+        if (string.IsNullOrWhiteSpace(options.RtmpUrl))
+            throw new ArgumentException("An RTMP ingestion URL is required.", nameof(options));
+
+        lock (_gate)
+        {
+            if (IsRunning) throw new InvalidOperationException("The encoder is already running.");
+            _options = options;
+        }
+
+        var ffmpegPath = await _locator.LocateAsync(cancellationToken).ConfigureAwait(false);
+        var encoder = options.VideoEncoder ?? await ProbeEncoderAsync(ffmpegPath, cancellationToken).ConfigureAwait(false);
+        var args = FfmpegArgs.Build(options, encoder);
+
+        var startInfo = new ProcessStartInfo
+        {
+            FileName = ffmpegPath,
+            UseShellExecute = false,
+            RedirectStandardInput = true,
+            RedirectStandardOutput = true,
+            RedirectStandardError = true,
+            CreateNoWindow = true,
+        };
+        foreach (var arg in args) startInfo.ArgumentList.Add(arg);
+
+        IEncoderProcess process;
+        try
+        {
+            process = _processFactory();
+            process.Start(startInfo);
+        }
+        catch (Exception ex)
+        {
+            AppLog.Write(ex, "FFmpeg encoder: failed to start subprocess");
+            lock (_gate) _options = null;
+            throw;
+        }
+
+        lock (_gate)
+        {
+            _process = process;
+            IsRunning = true;
+            _health = new StreamHealth { Status = StreamStatus.Streaming };
+        }
+
+        _stopRequested = false;
+        _stderrLoop = RunStderrLoopAsync(process);
+    }
+
+    /// <summary>
+    /// Write one raw BGRA frame to ffmpeg's stdin. Serialized internally; callers
+    /// (the compositor pump) may race freely. Frames are written as-is — the caller
+    /// paces to capture rate (the compositor's job, ship step 5).
+    /// </summary>
+    public async Task SubmitFrameAsync(VideoFrame frame, CancellationToken cancellationToken = default)
+    {
+        if (frame == null) throw new ArgumentNullException(nameof(frame));
+        IEncoderProcess? process;
+        lock (_gate)
+        {
+            if (!IsRunning) throw new InvalidOperationException("The encoder is not running.");
+            process = _process;
+        }
+
+        var bytes = frame.BgraPixels;
+        await process!.StandardInput.WriteAsync(bytes, cancellationToken).ConfigureAwait(false);
+        await process.StandardInput.FlushAsync(cancellationToken).ConfigureAwait(false);
+    }
+
+    public async Task StopAsync(CancellationToken cancellationToken = default)
+    {
+        IEncoderProcess? process;
+        Task? loop;
+        lock (_gate)
+        {
+            if (!IsRunning) return;
+            _stopRequested = true;
+            process = _process;
+            loop = _stderrLoop;
+        }
+
+        try
+        {
+            process!.StandardInput.Dispose(); // EOF → ffmpeg finalizes + exits
+        }
+        catch (Exception ex)
+        {
+            AppLog.Write(ex, "FFmpeg encoder: closing stdin failed");
+        }
+
+        try
+        {
+            using var timeout = CancellationTokenSource.CreateLinkedTokenSource(cancellationToken);
+            timeout.CancelAfter(TimeSpan.FromSeconds(10));
+            await process!.WaitForExitAsync(timeout.Token).ConfigureAwait(false);
+        }
+        catch (OperationCanceledException)
+        {
+            AppLog.Write("FFmpeg encoder: did not exit after stdin EOF — killing");
+            process!.Kill();
+        }
+        catch (Exception ex)
+        {
+            AppLog.Write(ex, "FFmpeg encoder: waiting for exit failed");
+            process!.Kill();
+        }
+
+        try
+        {
+            if (loop != null) await loop.ConfigureAwait(false);
+        }
+        catch (Exception ex)
+        {
+            AppLog.Write(ex, "FFmpeg encoder: stderr loop faulted during stop");
+        }
+
+        process.Dispose();
+
+        lock (_gate)
+        {
+            IsRunning = false;
+            _health.Status = StreamStatus.Offline;
+            _health.LastError = null;
+            _process = null;
+            _options = null;
+        }
+
+        AppLog.Write($"FFmpeg encoder stopped (exit {process.ExitCode})");
+    }
+
+    public void Dispose()
+    {
+        lock (_gate)
+        {
+            if (!IsRunning) return;
+            _process?.Kill();
+            _process?.Dispose();
+            _process = null;
+            IsRunning = false;
+        }
+    }
+
+    private async Task<string> ProbeEncoderAsync(string ffmpegPath, CancellationToken cancellationToken)
+    {
+        try
+        {
+            var startInfo = new ProcessStartInfo
+            {
+                FileName = ffmpegPath,
+                UseShellExecute = false,
+                RedirectStandardOutput = true,
+                RedirectStandardError = true,
+                CreateNoWindow = true,
+            };
+            startInfo.ArgumentList.Add("-hide_banner");
+            startInfo.ArgumentList.Add("-encoders");
+
+            using var probe = _processFactory();
+            probe.Start(startInfo);
+            using var cts = CancellationTokenSource.CreateLinkedTokenSource(cancellationToken);
+            cts.CancelAfter(TimeSpan.FromSeconds(15));
+            var output = await probe.StandardOutput.ReadToEndAsync(cts.Token).ConfigureAwait(false);
+            return FfmpegEncoderPicker.Pick(output);
+        }
+        catch (Exception ex)
+        {
+            AppLog.Write(ex, "FFmpeg encoder: encoder probe failed — falling back to software");
+            return FfmpegEncoderPicker.Preference[^1];
+        }
+    }
+
+    private Task RunStderrLoopAsync(IEncoderProcess process)
+    {
+        return Task.Run(async () =>
+        {
+            try
+            {
+                while (true)
+                {
+                    var line = await process.StandardError.ReadLineAsync().ConfigureAwait(false);
+                    if (line == null) break;
+                    OnStderrLine(process, line);
+                }
+
+                var code = process.ExitCode;
+                var stillRunning = false;
+                lock (_gate) stillRunning = IsRunning;
+                if (stillRunning && !_stopRequested && code != 0)
+                {
+                    AppLog.Write($"FFmpeg encoder: subprocess exited unexpectedly ({code})");
+                    _health.LastError = $"FFmpeg exited with code {code}";
+                    ProcessFailed?.Invoke(this, $"FFmpeg exited with code {code}");
+                }
+            }
+            catch (Exception ex)
+            {
+                AppLog.Write(ex, "FFmpeg encoder: stderr loop faulted");
+            }
+        });
+    }
+
+    private void OnStderrLine(IEncoderProcess process, string line)
+    {
+        var progress = FfmpegProgressParser.TryParse(line);
+        if (progress == null) return;
+
+        var dropped = Math.Max(0, (long)Math.Round(progress.Value.Fps * progress.Value.Duration.TotalSeconds) - progress.Value.Frame);
+
+        lock (_gate)
+        {
+            _health.CurrentBitrate = progress.Value.BitrateKbps;
+            _health.FPS = progress.Value.Fps;
+            _health.DroppedFrames = (int)dropped;
+            _health.StreamDuration = progress.Value.Duration;
+        }
+
+        HealthUpdated?.Invoke(this, _health);
+    }
+}

Services/Encoder/FfmpegEncoderPicker.cs

@@ -0,0 +1,35 @@
+namespace ytLive.Services.Encoder;
+
+/// <summary>
+/// Picks the best available H.264 encoder from ffmpeg's <c>-encoders</c> listing,
+/// honoring the license posture (no GPL libx264): hardware NVENC → QSV → AMF, then
+/// the OpenH264 software fallback. Pure parser — the <c>-encoders</c> probe output is
+/// fetched by the encoder via an <see cref="IEncoderProcess"/> and fed here.
+/// </summary>
+public static class FfmpegEncoderPicker
+{
+    /// <summary>Preference order, best first. All ship in the pinned BtbN lgpl-shared build.</summary>
+    public static readonly string[] Preference =
+    [
+        "h264_nvenc",
+        "h264_qsv",
+        "h264_amf",
+        "libopenh264",
+    ];
+
+    /// <summary>
+    /// First <see cref="Preference"/> entry present in the probe output, or the
+    /// software fallback (which the pinned build always contains) if none matched.
+    /// Never returns libx264 — it is GPL and would contaminate the paid product.
+    /// </summary>
+    public static string Pick(string probeOutput)
+    {
+        var available = probeOutput.Split('\n');
+        foreach (var name in Preference)
+        {
+            if (available.Any(line => line.Contains(name, StringComparison.Ordinal)))
+                return name;
+        }
+        return Preference[^1];
+    }
+}

Services/Encoder/FfmpegEncoderProcess.cs

@@ -0,0 +1,38 @@
+using System.Diagnostics;
+using System.IO;
+
+namespace ytLive.Services.Encoder;
+
+/// <summary>
+/// The real <see cref="IEncoderProcess"/>: a <see cref="Process"/> with all three
+/// std streams redirected. Constructed by <see cref="FfmpegEncoder"/> for both the
+/// encoder subprocess and the <c>-encoders</c> probe.
+/// </summary>
+public sealed class FfmpegEncoderProcess : IEncoderProcess
+{
+    private readonly Process _process;
+
+    public FfmpegEncoderProcess() => _process = new Process { EnableRaisingEvents = true };
+
+    public void Start(ProcessStartInfo startInfo)
+    {
+        _process.StartInfo = startInfo;
+        _process.Start();
+    }
+
+    public Stream StandardInput => _process.StandardInput.BaseStream;
+    public TextReader StandardOutput => _process.StandardOutput;
+    public TextReader StandardError => _process.StandardError;
+
+    public bool HasExited => _process.HasExited;
+    public int ExitCode => _process.ExitCode;
+    public void Kill()
+    {
+        if (!_process.HasExited) _process.Kill();
+    }
+
+    public Task WaitForExitAsync(CancellationToken cancellationToken = default)
+        => _process.WaitForExitAsync(cancellationToken);
+
+    public void Dispose() => _process.Dispose();
+}

Services/Encoder/FfmpegProgressParser.cs

@@ -0,0 +1,47 @@
+using System.Text.RegularExpressions;
+
+namespace ytLive.Services.Encoder;
+
+/// <summary>A decoded ffmpeg <c>-stats</c> progress line (pure data).</summary>
+public readonly record struct FfmpegProgress(
+    long Frame,
+    double Fps,
+    double BitrateKbps,
+    TimeSpan Duration,
+    long SizeBytes);
+
+/// <summary>
+/// Pure parser for ffmpeg's periodic <c>frame= fps= size= time= bitrate=</c> stderr
+/// lines (the <c>-stats</c>/<c>-stats_period</c> output). Unit-tested in isolation
+/// so the encoder loop stays a thin wire.
+/// </summary>
+public static class FfmpegProgressParser
+{
+    // frame=  123 fps= 59.9 q=28.0 size=   1024KiB time=00:00:02.04 bitrate= 4000.1kbits/s speed=1.00x
+    private static readonly Regex Line = new(
+        @"frame=\s*(?<frame>\d+)\s+fps=\s*(?<fps>[\d.]+).*?"
+        + @"size=\s*(?<size>\d+)KiB.*?"
+        + @"time=(?<time>\d{2}):(?<min>\d{2}):(?<sec>[\d.]+).*?"
+        + @"bitrate=\s*(?<bitrate>[\d.]+)kbits/s",
+        RegexOptions.Compiled | RegexOptions.CultureInvariant);
+
+    /// <summary>Returns null for non-progress lines (errors, warnings, banner).</summary>
+    public static FfmpegProgress? TryParse(string line)
+    {
+        if (string.IsNullOrWhiteSpace(line)) return null;
+        var m = Line.Match(line);
+        if (!m.Success) return null;
+
+        var frame = long.Parse(m.Groups["frame"].Value);
+        var fps = double.Parse(m.Groups["fps"].Value, System.Globalization.CultureInfo.InvariantCulture);
+        var size = long.Parse(m.Groups["size"].Value);
+        var bitrate = double.Parse(m.Groups["bitrate"].Value, System.Globalization.CultureInfo.InvariantCulture);
+
+        var hours = int.Parse(m.Groups["time"].Value);
+        var minutes = int.Parse(m.Groups["min"].Value);
+        var seconds = double.Parse(m.Groups["sec"].Value, System.Globalization.CultureInfo.InvariantCulture);
+        var duration = TimeSpan.FromSeconds(hours * 3600 + minutes * 60 + seconds);
+
+        return new FfmpegProgress(frame, fps, bitrate, duration, size * 1024);
+    }
+}

Services/Encoder/FramePump.cs

@@ -0,0 +1,272 @@
+using System;
+using System.Threading;
+using System.Threading.Tasks;
+using ytLive.Models;
+using ytLive.Services.Compositor;
+
+namespace ytLive.Services.Encoder;
+
+/// <summary>
+/// The live frame producer (TASK 4 ship step 5): the bridge between the capture
+/// managers + compositor and the encoder. While live it snapshots the active
+/// scene each tick, resolves every element to its latest frame, composites it
+/// into the tier's output frame, and paces frames into the encoder at the tier's
+/// FPS. All collaborators are constructor-injected seams (scene, resolver,
+/// options, encoder factory, pacing delay) so the pump stays free of WPF and of
+/// the capture managers and is fully hermetic in tests.
+///
+/// The RTMP URL comes from the options provider: until the live-stream create
+/// flow lands (TASK 5) it yields null, so go-live runs the existing visual flow
+/// without actually pushing.
+/// </summary>
+public sealed class FramePump : IDisposable
+{
+    private readonly Func<Scene?> _sceneProvider;
+    private readonly Func<SceneElement, VideoFrame?> _frameResolver;
+    private readonly Func<CompositorOptions> _compositorOptions;
+    private readonly Func<EncoderOptions?> _encoderOptions;
+    private readonly Func<IFfmpegEncoder> _encoderFactory;
+    private readonly Action<string>? _log;
+    private readonly Func<TimeSpan, CancellationToken, Task> _pacingDelay;
+    private readonly Func<(VideoFrame? Frame, SocialBarPosition Position)>? _socialBar;
+    private readonly SceneCompositor _compositor = new();
+
+    private readonly object _gate = new();
+    private IFfmpegEncoder? _encoder;
+    private CancellationTokenSource? _cts;
+    private Task? _pumpTask;
+    private bool _started;
+
+    /// <summary>Forwards the encoder's parsed health — ship step 6 binds this to the bottom bar.</summary>
+    public event EventHandler<StreamHealth>? HealthUpdated;
+
+    /// <summary>Raised when the encoder cannot start or dies mid-stream. The pump stops itself.</summary>
+    public event EventHandler<string>? Failed;
+
+    public FramePump(
+        Func<Scene?> sceneProvider,
+        Func<SceneElement, VideoFrame?> frameResolver,
+        Func<CompositorOptions> compositorOptions,
+        Func<EncoderOptions?> encoderOptions,
+        Func<IFfmpegEncoder> encoderFactory,
+        Action<string>? log = null,
+        Func<TimeSpan, CancellationToken, Task>? pacingDelay = null,
+        Func<(VideoFrame? Frame, SocialBarPosition Position)>? socialBar = null)
+    {
+        _sceneProvider = sceneProvider ?? throw new ArgumentNullException(nameof(sceneProvider));
+        _frameResolver = frameResolver ?? throw new ArgumentNullException(nameof(frameResolver));
+        _compositorOptions = compositorOptions ?? throw new ArgumentNullException(nameof(compositorOptions));
+        _encoderOptions = encoderOptions ?? throw new ArgumentNullException(nameof(encoderOptions));
+        _encoderFactory = encoderFactory ?? throw new ArgumentNullException(nameof(encoderFactory));
+        _log = log;
+        _pacingDelay = pacingDelay ?? ((delay, ct) => Task.Delay(delay, ct));
+        _socialBar = socialBar;
+    }
+
+    public bool IsRunning { get; private set; }
+
+    /// <summary>Never throws: failures are logged and surfaced via <see cref="Failed"/>,
+    /// so the VM can fire-and-forget it from a sync command handler.</summary>
+    public async Task StartAsync(CancellationToken cancellationToken = default)
+    {
+        lock (_gate)
+        {
+            if (_started) return;
+            _started = true;
+        }
+
+        IFfmpegEncoder? encoder = null;
+        try
+        {
+            var options = _encoderOptions();
+            if (options == null)
+            {
+                _log?.Invoke("FramePump: no RTMP URL available (live-stream create lands in TASK 5) — encoder skipped");
+                lock (_gate) _started = false;
+                return;
+            }
+
+            encoder = _encoderFactory();
+            encoder.HealthUpdated += OnHealthUpdated;
+            encoder.ProcessFailed += OnProcessFailed;
+            await encoder.StartAsync(options, cancellationToken);
+
+            lock (_gate)
+            {
+                _encoder = encoder;
+            }
+
+            // IsRunning must be true before the loop starts: the loop reads it on
+            // its first iteration, and with a completed-task delay it can run
+            // synchronously on this thread before PumpAsync even returns.
+            IsRunning = true;
+            _cts = new CancellationTokenSource();
+            _pumpTask = PumpAsync(options, _cts.Token);
+            _log?.Invoke($"FramePump started ({options.Width}×{options.Height} @ {options.Fps} fps)");
+        }
+        catch (Exception ex)
+        {
+            _log?.Invoke($"FramePump: start failed: {ex.Message}");
+            if (encoder != null)
+            {
+                encoder.HealthUpdated -= OnHealthUpdated;
+                encoder.ProcessFailed -= OnProcessFailed;
+                try
+                {
+                    encoder.Dispose();
+                }
+                catch (Exception disposeEx)
+                {
+                    _log?.Invoke($"FramePump: disposing failed encoder: {disposeEx.Message}");
+                }
+            }
+            lock (_gate)
+            {
+                _started = false;
+                IsRunning = false;
+            }
+            Failed?.Invoke(this, ex.Message);
+        }
+    }
+
+    public async Task StopAsync(CancellationToken cancellationToken = default)
+    {
+        IFfmpegEncoder? encoder;
+        Task? pump;
+        lock (_gate)
+        {
+            if (!_started && _encoder == null) return;
+            _started = false;
+            IsRunning = false;
+            encoder = _encoder;
+            pump = _pumpTask;
+            _cts?.Cancel();
+        }
+
+        // Stop the encoder BEFORE awaiting the pump: closing its stdin unblocks a
+        // write stuck on pipe backpressure, otherwise the pump could await forever.
+        if (encoder != null)
+        {
+            try
+            {
+                await encoder.StopAsync(cancellationToken);
+            }
+            catch (Exception ex)
+            {
+                _log?.Invoke($"FramePump: encoder stop failed: {ex.Message}");
+            }
+        }
+
+        if (pump != null)
+        {
+            try
+            {
+                await pump;
+            }
+            catch (Exception ex)
+            {
+                _log?.Invoke($"FramePump: pump loop faulted during stop: {ex.Message}");
+            }
+        }
+
+        if (encoder != null)
+        {
+            encoder.HealthUpdated -= OnHealthUpdated;
+            encoder.ProcessFailed -= OnProcessFailed;
+            try
+            {
+                encoder.Dispose();
+            }
+            catch (Exception ex)
+            {
+                _log?.Invoke($"FramePump: encoder dispose failed: {ex.Message}");
+            }
+        }
+
+        lock (_gate)
+        {
+            _encoder = null;
+            _cts = null;
+            _pumpTask = null;
+        }
+        _log?.Invoke("FramePump stopped");
+    }
+
+    public void Dispose()
+    {
+        try
+        {
+            StopAsync().GetAwaiter().GetResult();
+        }
+        catch (Exception ex)
+        {
+            _log?.Invoke($"FramePump: dispose failed: {ex.Message}");
+        }
+    }
+
+    private async Task PumpAsync(EncoderOptions options, CancellationToken ct)
+    {
+        var interval = TimeSpan.FromSeconds(1d / Math.Max(1, options.Fps));
+
+        try
+        {
+            while (!ct.IsCancellationRequested)
+            {
+                var scene = _sceneProvider();
+                if (scene != null)
+                {
+                    var compositorOptions = _compositorOptions();
+                    VideoFrame? socialBarFrame = null;
+                    var socialBarTop = 0;
+                    if (_socialBar != null)
+                    {
+                        var (barFrame, position) = _socialBar();
+                        socialBarFrame = barFrame;
+                        if (barFrame != null)
+                            socialBarTop = position == SocialBarPosition.Top
+                                ? 0
+                                : compositorOptions.SourceRectHeight - barFrame.Height;
+                    }
+                    var frame = _compositor.Render(
+                        scene, _frameResolver, null, compositorOptions, socialBarFrame, socialBarTop);
+                    IFfmpegEncoder? encoder;
+                    lock (_gate) encoder = _encoder;
+                    if (encoder == null) break; // _encoder is only cleared after the loop ends; defensive
+                    await encoder.SubmitFrameAsync(frame, ct);
+                }
+                await _pacingDelay(interval, ct);
+            }
+        }
+        catch (OperationCanceledException)
+        {
+            // normal stop
+        }
+        catch (Exception ex)
+        {
+            // A failure while the pump is supposed to run (encoder died under us,
+            // scene provider faulted, ...) stops the pump and surfaces once.
+            if (ct.IsCancellationRequested)
+            {
+                _log?.Invoke($"FramePump: pump exited during stop: {ex.Message}");
+            }
+            else
+            {
+                _log?.Invoke($"FramePump: pump loop faulted: {ex.Message}");
+                Failed?.Invoke(this, ex.Message);
+            }
+        }
+        finally
+        {
+            lock (_gate) IsRunning = false;
+        }
+    }
+
+    private void OnHealthUpdated(object? sender, StreamHealth health) => HealthUpdated?.Invoke(this, health);
+
+    private void OnProcessFailed(object? sender, string message)
+    {
+        _log?.Invoke($"FramePump: encoder process failed: {message}");
+        Failed?.Invoke(this, message);
+        _ = StopAsync();
+    }
+}

Services/Encoder/IEncoderProcess.cs

@@ -0,0 +1,26 @@
+using System.Diagnostics;
+using System.IO;
+
+namespace ytLive.Services.Encoder;
+
+/// <summary>
+/// Seam around a spawned subprocess (the encoder's ffmpeg and the encoder probe).
+/// Exposes the redirected stdin (binary frames), stdout (probe listing) and stderr
+/// (progress lines) plus exit control, so the encoder logic never touches
+/// <c>System.Diagnostics.Process</c> directly and tests can fake the whole thing.
+/// </summary>
+public interface IEncoderProcess : IDisposable
+{
+    void Start(ProcessStartInfo startInfo);
+
+    /// <summary>Raw binary stdin — the encoder writes BGRA frames here.</summary>
+    Stream StandardInput { get; }
+
+    TextReader StandardOutput { get; }
+    TextReader StandardError { get; }
+
+    bool HasExited { get; }
+    int ExitCode { get; }
+    void Kill();
+    Task WaitForExitAsync(CancellationToken cancellationToken = default);
+}

Services/Encoder/IFfmpegEncoder.cs

@@ -0,0 +1,25 @@
+using ytLive.Models;
+
+namespace ytLive.Services.Encoder;
+
+/// <summary>
+/// The live encoder seam (TASK 4 ship step 3): start an FFmpeg subprocess that
+/// encodes raw BGRA frames from stdin and pushes FLV to an RTMP ingestion URL,
+/// raising parsed health stats from stderr. The frame producer (compositor →
+/// capture managers, TASK 4 ship step 5) feeds <see cref="SubmitFrameAsync"/> at
+/// capture rate; this service serializes writes, parses progress, and tears the
+/// process down gracefully. Constructor-injected <see cref="IFfmpegLocator"/> +
+/// process factory keep it hermetic (tests fake both).
+/// </summary>
+public interface IFfmpegEncoder : IDisposable
+{
+    /// <summary>Fires on each parsed ffmpeg <c>-stats</c> progress line (~2 Hz).</summary>
+    event EventHandler<StreamHealth>? HealthUpdated;
+
+    /// <summary>Fires when the subprocess dies unexpectedly (non-zero exit while live).</summary>
+    event EventHandler<string>? ProcessFailed;
+
+    Task StartAsync(EncoderOptions options, CancellationToken cancellationToken = default);
+    Task SubmitFrameAsync(VideoFrame frame, CancellationToken cancellationToken = default);
+    Task StopAsync(CancellationToken cancellationToken = default);
+}

Services/GameAudioDetector.cs

@@ -0,0 +1,46 @@
+namespace ytLive.Services;
+
+/// <summary>
+/// Default <see cref="IGameAudioDetector"/>: samples a full-screen monitor
+/// provider (the existing <c>IFullScreenDetector</c>) and the live loopback
+/// level and advances a <see cref="GameAudioHysteresis"/>. The pure transitions
+/// live in GameAudioHysteresis (unit-tested); this wrapper owns the providers
+/// and the raised-changed event. WPF-free — the VM owns the poll timer.
+/// </summary>
+public sealed class GameAudioDetector : IGameAudioDetector
+{
+    private const float SoundFloor = 0.005f;
+
+    private readonly Func<int?> _foregroundFullScreenMonitorProvider;
+    private readonly Func<float> _loopbackLevelProvider;
+    private readonly Func<DateTime> _now;
+    private readonly GameAudioHysteresis _hysteresis = new();
+
+    /// <param name="foregroundFullScreenMonitorProvider">Returns the monitor a
+    /// full-screen foreground window covers, or null when windowed/none.</param>
+    /// <param name="loopbackLevelProvider">Current smoothed desktop/game level (0..1).</param>
+    /// <param name="now">Clock for the hysteresis windows; injectable for tests.</param>
+    public GameAudioDetector(
+        Func<int?> foregroundFullScreenMonitorProvider,
+        Func<float> loopbackLevelProvider,
+        Func<DateTime>? now = null)
+    {
+        _foregroundFullScreenMonitorProvider = foregroundFullScreenMonitorProvider;
+        _loopbackLevelProvider = loopbackLevelProvider;
+        _now = now ?? (() => DateTime.Now);
+    }
+
+    public bool IsGameAudioActive => _hysteresis.IsActive;
+
+    public event Action<bool>? IsGameAudioActiveChanged;
+
+    public void Poll()
+    {
+        var before = _hysteresis.IsActive;
+        var isFullScreen = _foregroundFullScreenMonitorProvider() != null;
+        var hasSound = _loopbackLevelProvider() > SoundFloor;
+        _hysteresis.Update(isFullScreen, hasSound, _now());
+        if (before != _hysteresis.IsActive)
+            IsGameAudioActiveChanged?.Invoke(_hysteresis.IsActive);
+    }
+}

Services/GameAudioHysteresis.cs

@@ -0,0 +1,57 @@
+namespace ytLive.Services;
+
+/// <summary>
+/// Pure show/hide state machine for the game audio bar (TASK 4 game audio).
+/// SHOW: a full-screen foreground app has been producing desktop audio for at
+/// least <see cref="ShowAfterSound"/> — "a working game with sound". HIDE: the
+/// app leaves fullscreen/foreground for <see cref="HideAfterWindowed"/> — the
+/// game is no longer up in the preview. Silence NEVER hides an active bar; it
+/// only matters for the initial show. No timers; <see cref="Update"/> is fed by
+/// the caller with a clock.
+/// </summary>
+public sealed class GameAudioHysteresis
+{
+    private readonly TimeSpan _showAfterSound = TimeSpan.FromMilliseconds(500);
+    private readonly TimeSpan _hideAfterWindowed = TimeSpan.FromSeconds(1);
+
+    private DateTime? _soundSince;
+    private DateTime? _windowedSince;
+
+    public bool IsActive { get; private set; }
+
+    public void Update(bool isFullScreen, bool hasSound, DateTime now)
+    {
+        if (isFullScreen)
+        {
+            _windowedSince = null;
+            if (IsActive)
+                return;
+
+            if (!hasSound)
+            {
+                _soundSince = null;
+                return;
+            }
+
+            _soundSince ??= now;
+            if (now - _soundSince >= _showAfterSound)
+                IsActive = true;
+        }
+        else
+        {
+            _soundSince = null;
+            if (!IsActive)
+            {
+                _windowedSince = null;
+                return;
+            }
+
+            _windowedSince ??= now;
+            if (now - _windowedSince >= _hideAfterWindowed)
+            {
+                IsActive = false;
+                _windowedSince = null;
+            }
+        }
+    }
+}

Services/IGameAudioDetector.cs

@@ -0,0 +1,20 @@
+namespace ytLive.Services;
+
+/// <summary>
+/// Detects "a working game with sound is up in the preview" (TASK 4 game audio
+/// bar): becomes active once a full-screen foreground app is producing desktop
+/// audio, and stays active as long as that full-screen app remains — silence
+/// never hides the bar, only the game leaving fullscreen/foreground does. Seam
+/// so the VM and tests never touch Win32 or audio interop directly.
+/// </summary>
+public interface IGameAudioDetector
+{
+    /// <summary>True while the game audio bar should be visible.</summary>
+    bool IsGameAudioActive { get; }
+
+    /// <summary>Raised when the bar should appear or disappear.</summary>
+    event Action<bool>? IsGameAudioActiveChanged;
+
+    /// <summary>Samples the injected providers and advances the state machine.</summary>
+    void Poll();
+}

Services/ScreenCaptureManager.cs

@@ -156,6 +156,15 @@ public sealed class ScreenCaptureManager : IDisposable
         toStop.PreviewBitmap = null;
     }
 
+    /// <summary>The most recent frame for a capture key, or null before the first
+    /// frame arrives (or if the key has no session). The live compositor reads
+    /// the backdrop from here.</summary>
+    public VideoFrame? GetLatestFrame(string key)
+    {
+        lock (_gate)
+            return _sessions.TryGetValue(key, out var session) ? session.LatestFrame : null;
+    }
+
     public void Dispose()
     {
         List<CaptureSession> sessions;

Services/SocialValidator.cs

@@ -23,6 +23,11 @@ public sealed class SocialLookupResult
 public interface ISocialValidator
 {
     Task<SocialLookupResult> LookupAsync(SocialService service, string handleOrUrl, CancellationToken ct);
+
+    /// <summary>Best-effort nodeinfo software name (mastodon/peertube/...) for a
+    /// fediverse domain, or null when it can't be resolved. The load-time heal
+    /// uses this to fix a bar entry whose stored software is missing.</summary>
+    Task<string?> ResolveFediverseSoftwareAsync(string domain, CancellationToken ct);
 }
 
 /// <summary>
@@ -35,14 +40,19 @@ public interface ISocialValidator
 public sealed class HttpSocialValidator : ISocialValidator
 {
     private readonly HttpClient _client;
+    private readonly Action<string>? _log;
 
-    public HttpSocialValidator(HttpClient? client = null)
+    public HttpSocialValidator(HttpClient? client = null, Action<string>? log = null)
     {
         _client = client ?? new HttpClient();
         _client.DefaultRequestHeaders.UserAgent.ParseAdd(
             "Mozilla/5.0 (compatible; ytLlive social validator)");
+        _log = log;
     }
 
+    public Task<string?> ResolveFediverseSoftwareAsync(string domain, CancellationToken ct)
+        => TryFetchFediverseSoftwareAsync(domain, ct);
+
     public async Task<SocialLookupResult> LookupAsync(SocialService service, string handleOrUrl, CancellationToken ct)
     {
         var input = handleOrUrl.Trim();
@@ -127,32 +137,67 @@ public sealed class HttpSocialValidator : ISocialValidator
     /// nodeinfo link, read `software.name`. If the identity domain is itself a
     /// redirect (e.g. a YunoHost domain whose default app lives on a subdomain),
     /// the bare root 302s to the real instance — follow it and ask that host.
-    /// Failures return null — validation still succeeds, the icon just falls
-    /// back to the generic fediverse glyph.
+    /// If neither answers, probe well-known subdomains (mastodon.example.com)
+    /// so a landing-page domain still resolves its real instance. The whole
+    /// resolution is bounded by a ~15s budget. Failures return null — validation
+    /// still succeeds, the icon just falls back to the generic fediverse glyph.
     /// </summary>
     private async Task<string?> TryFetchFediverseSoftwareAsync(string domain, CancellationToken ct)
     {
         try
         {
-            var software = await FetchSoftwareNameAsync(domain, ct);
+            using var budget = System.Threading.CancellationTokenSource.CreateLinkedTokenSource(ct);
+            budget.CancelAfter(TimeSpan.FromSeconds(15));
+
+            var software = await FetchSoftwareNameAsync(domain, budget.Token);
             if (software != null) return software;
 
-            var resolved = await ResolveInstanceHostAsync(domain, ct);
-            if (resolved == null
-                || string.Equals(resolved, domain, System.StringComparison.OrdinalIgnoreCase))
+            var resolved = await ResolveInstanceHostAsync(domain, budget.Token);
+            if (resolved != null
+                && !string.Equals(resolved, domain, System.StringComparison.OrdinalIgnoreCase))
+            {
+                software = await FetchSoftwareNameAsync(resolved, budget.Token);
+                if (software != null) return software;
+            }
+
+            foreach (var sub in FediverseSubdomainCandidates)
+            {
+                var host = $"{sub}.{domain}";
+                software = await FetchSoftwareNameAsync(host, budget.Token);
+                if (software != null)
+                {
+                    _log?.Invoke($"SocialValidator: fediverse software '{software}' for '{domain}' resolved via {host}");
+                    return software;
+                }
+            }
+            _log?.Invoke($"SocialValidator: no nodeinfo found for '{domain}'");
             return null;
-            return await FetchSoftwareNameAsync(resolved, ct);
         }
         catch (System.OperationCanceledException) when (ct.IsCancellationRequested)
         {
             return null; // caller checks ct.IsCancellationRequested and reports Canceled
         }
-        catch
+        catch (System.OperationCanceledException)
         {
+            _log?.Invoke($"SocialValidator: nodeinfo resolution for '{domain}' timed out");
+            return null;
+        }
+        catch (System.Exception ex)
+        {
+            _log?.Invoke($"SocialValidator: nodeinfo resolution for '{domain}' failed: {ex.Message}");
             return null;
         }
     }
 
+    /// <summary>Common instance subdomains, probed in order when the identity
+    /// domain itself doesn't serve nodeinfo (a landing page or SSO gate in front
+    /// of a self-hosted instance).</summary>
+    private static readonly string[] FediverseSubdomainCandidates =
+    {
+        "mastodon", "social", "fediverse", "tube", "peertube",
+        "pixelfed", "lemmy", "pleroma", "misskey", "gotosocial", "fedi", "instance",
+    };
+
     private async Task<string?> FetchSoftwareNameAsync(string domain, CancellationToken ct)
     {
         var nodeInfoUrl = await FetchNodeInfoUrlAsync(domain, ct);

Services/index.md

@@ -27,13 +27,33 @@ External-facing logic: YouTube API, persistence. See
 | `ScreenCaptureFrameSource.cs` | One `Direct3D11CaptureFramePool` (free-threaded, 2 buffers) + session per target; frames → `SoftwareBitmap.CreateCopyFromSurfaceAsync` (BGRA, alpha ignored) → `VideoFrame`, bytes read via `WindowsRuntimeMarshal.TryGetDataUnsafe` (CsWinRT-safe — the `IMemoryBufferByteAccess` ComImport cast fails on every frame and is gone). Surfaces > 1920×1080 downscaled bilinearly to the master; conversion failures logged ≤ once/5 s. DRM content = black frames (OS limit). `CreateForMonitor`/`CreateForWindow`/`CreateForPicker` |
 | `ScreenCaptureManager.cs` | Screen-capture ownership mirroring `CameraManager`: refcounted by target key, one shared `WriteableBitmap`, dispatcher-coalesced latest-frame copies; `PreviewBitmapChanged`/`CaptureFailed` events; `ReleaseAllAsync` used on re-designation |
 | `ScreenCaptureSourceFactory.cs` | `Resolve(key)` parses `monitor:<n>` / `window:<hwnd>` / `picker:<name>` into a source; `PickAsync()` shows the OS `GraphicsCapturePicker` and returns the `picker:` key (transient — a reload falls back to auto-detection) |
-| `Compositor/SceneCompositor.cs` | **The output compositor (TASK 4 ship step 1)**: renders a scene into the encoder's master `VideoFrame` (tightly-packed BGRA8), mirroring the XAML preview minus editing chrome — backdrop → background → elements (`UniformToFill` cover-crop, round clip, mirror, opacity, border) → branding flash. Pure and WPF-free: frames injected via a `Func<SceneElement, VideoFrame?>` resolver (webcam → DeviceId, image → AssetId, backdrop → CaptureKey); output sized by `CompositorOptions` (16:9 = full master 1:1; vertical 9:16 = 607×1080 crop → 1080×1920 bilinear). Preview stays XAML (editing view); this is the output view — see `ai.md` "Scene compositor" |
+| `Compositor/SceneCompositor.cs` | **The output compositor (TASK 4 ship step 1)**: renders a scene into the encoder's master `VideoFrame` (tightly-packed BGRA8), mirroring the XAML preview minus editing chrome — backdrop → background → elements (`UniformToFill` cover-crop, round clip, mirror, opacity, border) → branding flash → social bar (optional `socialBarFrame` + `socialBarTop` in master space, blitted last so the bar sits above the flash; the old `BlitFlash` generalized to `BlitOverlay` with source offsets). Pure and WPF-free: frames injected via a `Func<SceneElement, VideoFrame?>` resolver (webcam → DeviceId, image → AssetId, backdrop → CaptureKey); output sized by `CompositorOptions` (16:9 = full master 1:1; vertical 9:16 = 607×1080 crop → 1080×1920 bilinear). Preview stays XAML (editing view); this is the output view — see `ai.md` "Scene compositor" |
 | `Compositor/CompositorOptions.cs` | The active tier's output rect (source space over the 1920×1080 master, integer-aligned — `MainViewModel.OutputRectX` can be 656.5) + target W×H |
 | `Compositor/StretchMath.cs` | Pure pixel math: the WPF `UniformToFill` cover-crop, clamped bilinear sample/scale (unit-tested half of the compositor) |
 | `Compositor/StaticPixelCache.cs` | Asset bytes → cached BGRA8 `VideoFrame`, decoded once per content hash — the output path's raw-pixel source (the preview uses ImageCache's `BitmapImage`) |
 | `Encoder/IFfmpegLocator.cs` | **TASK 4 ship step 2 seam**: resolves an absolute path to `ffmpeg.exe` (PATH first → cached `%APPDATA%\ytLlive\tools\ffmpeg.exe` → pinned BtbN LGPL-shared zip download). The encoder step and tests fake it |
-| `SocialValidator.cs` | `ISocialValidator` seam + `HttpSocialValidator` default: validates a social handle/URL by constructing the canonical profile URL and issuing an HTTP GET — the "act of validation" before adding to the bar. 200/redirect = exists; 404/connection failure = rejected. Fediverse `@user@domain` additionally does a best-effort nodeinfo lookup (`/.well-known/nodeinfo` → `software.name`) so the entry can show the instance's real logo; nodeinfo failure still validates (generic fediverse glyph). If the identity domain's nodeinfo is blocked (SSO) but the bare root 302s to the real instance (YunoHost default-app subdomains), the lookup follows the redirect and asks that host instead. Constructor takes optional `HttpClient` for tests |
-| `Encoder/FfmpegLocator.cs` | The default locator: PATH probe wins, then the cache, then pull+extract (`ffmpeg.exe` **+ the `libav*.dll` family** via a staging dir, failures via `AppLog`). Pinned to BtbN `autobuild-2026-08-09-13-03` **lgpl-shared** (dynamic linking = LGPL compliance without static-relink §6 material; no GPL libx264; NVENC/QSV/AMF + libopenh264 + native AAC — see `ai.md` → Licensing). Search dirs / tools dir / downloader constructor-injected for hermetic tests. Not yet constructed by the app (the encoder step wires it) |
+| `SocialValidator.cs` | `ISocialValidator` seam + `HttpSocialValidator` default: validates a social handle/URL by constructing the canonical profile URL and issuing an HTTP GET — the "act of validation" before adding to the bar. 200/redirect = exists; 404/connection failure = rejected. Fediverse `@user@domain` additionally does a best-effort nodeinfo lookup (`/.well-known/nodeinfo` → `software.name`) so the entry can show the instance's real logo; nodeinfo failure still validates (generic fediverse glyph). If the identity domain's nodeinfo is blocked (SSO) but the bare root 302s to the real instance (YunoHost default-app subdomains), the lookup follows the redirect and asks that host. Since the bar bug-fix branch the resolution **probes well-known subdomains** (`mastodon.`, `social.`, ... order in `FediverseSubdomainCandidates`) when both the identity domain and its redirect come up empty, bounded by a ~15s linked-CTS budget; `ResolveFediverseSoftwareAsync(domain, ct)` on the seam powers the load-time heal. Constructor takes optional `HttpClient` + `Action<string>` log for tests |
+| `Compositor/SocialBarRenderer.cs` | **Social bar output strip** (bar bug-fix branch): rasterizes the global social bar into a transparent straight-alpha BGRA8 `VideoFrame` strip (1920 wide, 40px content + 24px glow pad) via `RenderTargetBitmap` — one Path (logo) + one TextBlock (handle) per entry, white on transparent with the preview's green `#2ecc71` glow baked in (Pbgra32 → straight-alpha unpremultiply). UI thread only; the frame is immutable afterwards so the `FramePump` reads it from its own thread |
+| `Encoder/EncoderOptions.cs` | One go-live's encoder config: full `RtmpUrl` (ingest + stream key), W×H/FPS/bitrate from the quality tier, `VideoEncoder` (null = probe), audio sample rate/channels, `GopSize` = FPS×4 (the ≤4s keyframe bound) |
+| `Encoder/IFfmpegEncoder.cs` | **TASK 4 ship step 3 seam**: start/feed/stop the live encoder; `HealthUpdated` (parsed `StreamHealth`), `ProcessFailed` on unexpected non-zero exit. Constructor-injected locator + process factory (tests fake both) |
+| `Encoder/FfmpegEncoder.cs` | The default encoder: spawn `ffmpeg.exe` (probe `-encoders` first → hardware NVENC/QSV/AMF, OpenH264 fallback — never libx264), feed raw BGRA frames into stdin, parse `-stats` lines into `StreamHealth`, graceful stop via stdin EOF + 10s kill watchdog. Constructed by `MainViewModel` since ship step 5 (`new FfmpegEncoder(new FfmpegLocator())`), driven by the `FramePump` |
+| `Encoder/IEncoderProcess.cs` | Seam around the spawned subprocess (probe + encoder): redirected stdin/stdout/stderr + exit control — the encoder never touches `Process` directly |
+| `Encoder/FfmpegEncoderProcess.cs` | The real process wrapper (`Process` with all three std streams redirected) |
+| `Encoder/FfmpegArgs.cs` | Pure FFmpeg command-line builder: rawvideo `pipe:0` input, `anullsrc` silent audio (WASAPI replaces it), H.264+AAC, closed GOP (`-g fps×4 -keyint_min -sc_threshold 0 -bf 0`, `yuv420p`), FLV → RTMP |
+| `Encoder/FfmpegProgressParser.cs` | Pure parser for `frame=/fps=/size=/time=/bitrate=` stats lines → `FfmpegProgress` |
+| `Encoder/FfmpegEncoderPicker.cs` | Pure H.264 encoder picker from `-encoders` output: NVENC → QSV → AMF → OpenH264; **never returns libx264** (GPL) |
+| `Encoder/FramePump.cs` | **TASK 4 ship step 5**: the live frame producer — while live it snapshots the active scene each tick, resolves every element to its latest frame (`Func<SceneElement, VideoFrame?>` resolver), composites it into the tier's output frame, and paces frames into the encoder at the tier's FPS. All collaborators constructor-injected seams; free of WPF and the capture managers. `StartAsync` never throws (failures log + `Failed`); no RTMP URL = encoder skipped; `StopAsync` stops the encoder before awaiting the loop (backpressure deadlock); `ProcessFailed` self-stops. Since the bar bug-fix branch it takes an optional `socialBar: Func<(VideoFrame? Frame, SocialBarPosition Position)>?` seam — a pre-rendered bar strip composited last (above the flash) at the top edge or `SourceRectHeight − bar height`. See `ai.md` "Live frame pipeline" |
+| `Encoder/FfmpegLocator.cs` | The default locator: PATH probe wins, then the cache, then pull+extract (`ffmpeg.exe` **+ the `libav*.dll` family** via a staging dir, failures via `AppLog`). Pinned to BtbN `autobuild-2026-08-09-13-03` **lgpl-shared** (dynamic linking = LGPL compliance without static-relink §6 material; no GPL libx264; NVENC/QSV/AMF + libopenh264 + native AAC — see `ai.md` → Licensing). Search dirs / tools dir / downloader constructor-injected for hermetic tests. Wired into the encoder since ship step 5 |
+| `Audio/IAudioSource.cs` | **TASK 4 ship step 4 seam**: live capture source — `Start`/`Stop`/`Started`/`SampleReady(AudioSample)`/`Failed(Exception)`, `IDisposable`. Capture now runs for the app's lifetime (started at startup) so the footer meters preview live. The app consumes this seam; tests inject hermetic fakes |
+| `Audio/AudioSample.cs` | One captured chunk: interleaved PCM float (-1..1) + sample rate + channels |
+| `Audio/WasapiLoopbackAudioSource.cs` | Desktop/game capture: NAudio `WasapiLoopbackCapture` on the default render device — automatic at unity; the game bar's meter consumes it |
+| `Audio/WasapiMicAudioSource.cs` | Mic capture: NAudio `WasapiCapture` with the device resolved by `FriendlyName` matching `MicSourceName` (DisplayName only), default capture endpoint fallback; name provider `Func<string?>` re-read at each `Start` so a device picked mid-session takes effect immediately (the mixer restarts the mic on pick) |
+| `Audio/AudioMixer.cs` | Owns both sources; capture starts once at startup (`MainViewModel.StartMicCaptureAsync`) and stops on `Shutdown` — NOT go-live (preview monitoring). Mic samples → `AudioLevelMeter` → `MicLevelChanged`; loopback samples → the game bar's meter via `LoopbackLevelChanged`. Surfaces mic connection state: `MicConnected`/`MicFailed` (drives the status dot) + `RestartMic()` (device swap mid-session, keeps loopback). Failures log via `AppLog`; mic failure zeroes the meter, loopback failure doesn't kill the mic. Note: the meter `Push` is unconditional (the `?.` on the event would otherwise skip the argument when nothing is subscribed) |
+| `Audio/AudioLevelMeter.cs` | Pure smoothed RMS level (0..1): `Push(AudioSample)` + `Reset` — the unit-tested math behind `AudioLevel` and `GameAudioLevel`. `ToDisplay(float)` maps the raw linear RMS onto the meter's display scale (−60..0 dBFS spread across 0..1) — real speech/game RMS (~0.01..0.1) would otherwise leave a flat scale looking dead |
+| `Audio/WaveToFloat.cs` | Pure WASAPI buffer → float conversion: IEEE float 32-bit direct, PCM 16-bit normalized, `WaveFormatExtensible` IEEE-float subformat GUID, trailing partial samples ignored |
+| `IGameAudioDetector.cs` | **TASK 4 game audio bar seam**: `IsGameAudioActive` + `IsGameAudioActiveChanged` + `Poll()` — detects "a working game with sound is up in the preview" |
+| `GameAudioHysteresis.cs` | Pure show/hide state machine for the game bar: SHOW = full-screen app holds sound ~500ms; HIDE = the app leaves fullscreen ~1s. **Silence never hides an active bar** — only the game leaving the preview does (creator's rule). No timers; `Update(isFullScreen, hasSound, now)` |
+| `GameAudioDetector.cs` | Default `IGameAudioDetector`: composes a full-screen monitor provider (`IFullScreenDetector.GetForegroundFullScreenMonitorIndex`) + the live loopback level (floor 0.5%) into a `GameAudioHysteresis`. WPF-free; the VM owns the 250ms poll timer |
 
 Related: constructed in [`ViewModels/MainViewModel.cs`](../ViewModels/MainViewModel.cs)
 (no DI container yet). Models in [`Models/index.md`](../Models/index.md).

TASKS.md

@@ -106,7 +106,7 @@ Lifecycle: `created → ready → [testing] → live → complete` (transitional
 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)
+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
@@ -115,6 +115,8 @@ Lifecycle: `created → ready → [testing] → live → complete` (transitional
 18. ☐ **Chat box** — YouTube live chat rendered *on* the stream so viewers read along in-video
 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. ☐ **Logo + richer in-app About (2026-08-13, queued)** — the ytLlive wordmark in the top bar is clickable and opens the About overlay; make a real **logo** (CC0 per the icon guardrail), and expand the About overlay into the creator's hub: **links to premium unlock + coffee/thanks buys + socials** and a second (or third) **scrolling panel with the full licensing/legal texts on demand** — everything stays IN-APP (no Notepad, no browser tab; the app is standalone). The top-bar About button that opened `THIRD-PARTY-NOTICES.txt` in the OS viewer was removed on 2026-08-13 for exactly this reason
+22. ☐ **Voice filters on the mic channel (2026-08-13, queued — KISS, always on)** — 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). Always-on — no UI knobs; the mic stays the creator's single audio control
 
 ### The Minimal Source Set (design decision — do not expand casually)
 
@@ -199,10 +201,10 @@ Preview shows the transition too (WYSIWYG). No wipes/slides/LUTs beyond the four
 
 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** — the FFmpeg subprocess: frames via stdin, stderr health parsing, FLV mux + push to the cached reusable stream's ingestion URL
-4. ☐ **WASAPI audio capture** — loopback (desktop/game) + the picked mic feeding `AudioLevel` so the realtime meter comes alive (req 7)
-5. ☐ **Frame-pipeline wiring** — `CameraManager`/`ScreenCaptureManager` → compositor resolver → encoder
-6. ☐ **Health stats** — bitrate, FPS, dropped frames reported live in the bottom bar (req 5)
+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 5 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** — Go Live always creates/updates the broadcast with `privacyStatus = "private"` + PRIVATE badge (req 8, test-verifiable)
 
 The pipeline chain the encoder needs doesn't exist yet: **scene compositing** (the master 1920×1080 frame
@@ -336,8 +338,8 @@ provides one.
 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 and surfaced via the top-bar **About** button (`MainWindow` code-behind, opens the file in the
-   OS viewer).
+   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
@@ -355,12 +357,173 @@ parsing), RTMP push, WASAPI audio capture, the frame-pipeline wiring, health sta
 
 **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 and is surfaced by a new
-top-bar **About** button; the "never do" licensing guardrails are recorded in `ai.md` — build **0 warnings**.
+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 5); 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 — YouTube Live Stream Management
@@ -440,6 +603,26 @@ cache refresh, empty payload, missing zip entry, downloader failure) — **78 pa
 
 ---
 
+## TASK 7 — 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()`.
+
+---
+
 ## Backlog (future versions)
 
 1. v0.2 — Recording to local file (recordings carry the branding flash — see TASK 3 / `ai.md` Monetization)

THIRD-PARTY-NOTICES.txt

@@ -7,9 +7,10 @@ its source, so the LGPL/BSD/MIT obligations are met. Distribution obligations
 are NOT optional: they attach because this product ships or automates the
 download of these components.
 
-If this file changes, update it here AND in the app's About screen (it opens
-this file). See TASKS.md (TASK 4) and ai.md ("Licensing — do not violate") for
-the guardrails — the "never do" list is there on purpose.
+If this file changes, update it here AND in the app's About screen (the About
+overlay's licensing panel surfaces this file in-app). See TASKS.md (TASK 4) and
+ai.md ("Licensing — do not violate") for the guardrails — the "never do" list is
+there on purpose.
 
 --------------------------------------------------------------------------------
 
@@ -79,6 +80,14 @@ the guardrails — the "never do" list is there on purpose.
             obligations; it is listed here per this file's "list everything"
             policy.
 
+9. NAudio  (WASAPI audio capture — loopback + mic)
+   Copyright (c) Mark Heath and contributors
+   License: MIT
+   Home:    https://github.com/naudio/NAudio
+   Used as: the WASAPI loopback (desktop/game audio) and mic capture sources
+            behind the `IAudioSource` seam (TASK 4 ship step 4). MIT imposes
+            no source offer; this notice is kept per this file's policy.
+
 --------------------------------------------------------------------------------
 
 MISCELLANEOUS

ViewModels/MainViewModel.cs

@@ -14,6 +14,9 @@ using Microsoft.Win32;
 using ytLive.Helpers;
 using ytLive.Models;
 using ytLive.Services;
+using ytLive.Services.Audio;
+using ytLive.Services.Compositor;
+using ytLive.Services.Encoder;
 
 namespace ytLive.ViewModels;
 
@@ -24,6 +27,8 @@ public class MainViewModel : ViewModelBase
     private readonly YouTubeChatService _youtubeChat;
     private readonly DispatcherTimer _liveTimer;
     private readonly DispatcherTimer _volumeFlashTimer;
+    private readonly DispatcherTimer _gameVolumeFlashTimer;
+    private readonly DispatcherTimer _gameAudioTimer;
 
     private Scene? _activeScene;
     private SceneElement? _selectedElement;
@@ -38,6 +43,14 @@ public class MainViewModel : ViewModelBase
     private bool _micMuted;
     private double? _volumeBeforeMute;
     private string? _micSourceName;
+    private MicStatus _micStatus = MicStatus.NotConnected;
+    private double _gameAudioLevel;
+    private bool _gameVolumeAdjusting;
+    private bool _gameVolumeFlash;
+    private double _gameVolume = 1.0;
+    private bool _gameMuted;
+    private double? _gameVolumeBeforeMute;
+    private bool _isGameAudioBarVisible;
     private StreamStatus _streamStatus = StreamStatus.Offline;
     private StreamHealth _currentHealth = new();
     private string _streamTitle = string.Empty;
@@ -48,7 +61,7 @@ public class MainViewModel : ViewModelBase
     private string _previewGlowBrush = "Transparent";
     private Thickness _previewGlowThickness = new(0);
     private string _liveElapsedText = "00:00:00";
-    private double _livePulseOpacity = 1.0;
+    private double _recDotPulse = 1.0;
     private TimeSpan _liveElapsed;
 
     private bool _isSettingsOpen;
@@ -77,14 +90,30 @@ public class MainViewModel : ViewModelBase
     private Webcam? _webcam;
     private string? _webcamError;
     private SocialsConfig? _socials;
+    private VideoFrame? _socialBarFrame;
     private readonly IMicrophoneEnumerator _microphoneEnumerator;
 
+    // Live audio capture (TASK 4 ship step 4): desktop/game via WASAPI loopback,
+    // mic via WASAPI capture, both owned by the mixer. Capture runs for the app's
+    // lifetime (started at startup, stopped on shutdown) so the footer meters
+    // stay live in preview. Mic level feeds AudioLevel (the meter); loopback
+    // feeds the game audio bar's meter. Private by design — the mixer surfaces
+    // the levels + mic connection state to the UI.
+    private readonly AudioMixer _audioMixer;
+
+    // Live frame pipeline (TASK 4 ship step 5): composites the active scene at the
+    // tier's FPS and paces frames into the encoder. The RTMP URL seam stays null
+    // until the live-stream create flow (TASK 5) supplies the reusable stream URL.
+    private readonly Func<string?> _rtmpUrlProvider;
+    private readonly FramePump _framePump;
+
     // Screen backdrop: a permanent live capture (desktop/game) that every scene
     // shows at the bottom layer. One shared capture session per key — the
     // ScreenCaptureManager refcounts by key, mirroring CameraManager.
     private readonly IFullScreenDetector _fullScreenDetector;
     private readonly ScreenCaptureManager _screenCaptureManager;
     private readonly ScreenCaptureSourceFactory _screenCaptureFactory;
+    private readonly IGameAudioDetector _gameAudioDetector;
     private int? _lastForegroundFullScreenMonitor;
     private CancellationTokenSource? _deactivateCts;
     private ImageSource? _backdropImage;
@@ -223,7 +252,10 @@ public class MainViewModel : ViewModelBase
             {
                 OnPropertyChanged(nameof(IsOffline));
                 OnPropertyChanged(nameof(IsLive));
-                OnPropertyChanged(nameof(LiveIndicatorVisible));
+                OnPropertyChanged(nameof(RecDotBrush));
+                OnPropertyChanged(nameof(RecTextBrush));
+                OnPropertyChanged(nameof(RecDotOpacity));
+                OnPropertyChanged(nameof(IsLivePrivate));
                 OnPropertyChanged(nameof(ShowStartStream));
                 OnPropertyChanged(nameof(ShowChatInactiveMessage));
                 OnPropertyChanged(nameof(ShowPreviewPlaceholder));
@@ -256,8 +288,9 @@ public class MainViewModel : ViewModelBase
         private set => SetProperty(ref _accountDisplayName, value);
     }
 
-    // ─── Audio (KISS: desktop/game audio is automatic — zero UI. The creator's
-    // ─── only audio control is the mic: meter + volume + mute.) ───
+    // ─── Audio: the mic bar (meter + volume + mute + status dot) is always
+    // ─── visible; the game bar (meter + volume + mute) appears only while a
+    // ─── full-screen game is producing sound. Both meters preview live. ───
 
     /// <summary>Live mic input level (0..1) — fed by the audio mixer once capture
     /// lands; 0 with no input. Read by the meter, scaled by MicVolume.</summary>
@@ -279,7 +312,7 @@ public class MainViewModel : ViewModelBase
     /// level flashes on the bar) so the creator sees where they're setting it;
     /// otherwise the realtime live level scaled by volume (raising the volume
     /// moves ambient noise up the bar). Read-only meter.</summary>
-    private double MeterLevel => MicMuted ? 0 : _volumeAdjusting || _volumeFlash ? MicVolume : Math.Min(1, AudioLevel * MicVolume);
+    private double MeterLevel => MicMuted ? 0 : _volumeAdjusting || _volumeFlash ? MicVolume : Math.Min(1, AudioLevelMeter.ToDisplay((float)AudioLevel) * MicVolume);
 
     public double MeterFillWidth => MeterLevel * 288;
 
@@ -393,12 +426,178 @@ public class MainViewModel : ViewModelBase
             Owner = System.Windows.Application.Current?.MainWindow
         };
         if (dialog.ShowDialog() == true && dialog.PickedDevice != null)
+        {
             MicSourceName = dialog.PickedDevice.DisplayName;
+            _audioMixer.RestartMic(); // swap the live device immediately
+        }
+    }
+
+    // ─── Mic status dot (the MIC button) ───
+
+    private static readonly SolidColorBrush MicProblemBrush = CreateBrush("#f1c40f");
+
+    /// <summary>Mic connection state, driven by the mixer's MicConnected/MicFailed
+    /// events and the startup device check (see StartMicCaptureAsync).</summary>
+    public MicStatus MicStatus
+    {
+        get => _micStatus;
+        private set
+        {
+            if (SetProperty(ref _micStatus, value))
+            {
+                OnPropertyChanged(nameof(MicStatusBrush));
+                OnPropertyChanged(nameof(MicStatusToolTip));
+            }
+        }
+    }
+
+    /// <summary>Status dot: green = connected, yellow = problem with the requested
+    /// connection, red = not connected (no device / not started).</summary>
+    public SolidColorBrush MicStatusBrush => MicStatus switch
+    {
+        MicStatus.Connected => BarOnBrush,
+        MicStatus.Problem => MicProblemBrush,
+        _ => BarOffBrush,
+    };
+
+    public string MicStatusToolTip => MicStatus switch
+    {
+        MicStatus.Connected => "Mic connected — click to change",
+        MicStatus.Problem => "Mic problem — the requested microphone is unavailable (in use or unplugged). Click to change",
+        _ => "No mic connected — click to choose a microphone",
+    };
+
+    // ─── Game audio bar (desktop/game): visible only while a full-screen game
+    // ─── is producing sound (IGameAudioDetector). Meter + mute + volume mirror
+    // ─── the mic bar. ───
+
+    /// <summary>True while the game audio bar should be shown (driven by
+    /// IGameAudioDetector via the poll timer).</summary>
+    public bool IsGameAudioBarVisible
+    {
+        get => _isGameAudioBarVisible;
+        private set => SetProperty(ref _isGameAudioBarVisible, value);
+    }
+
+    /// <summary>Live desktop/game input level (0..1), fed by the mixer's loopback
+    /// capture. Read by the game meter, scaled by GameAudioVolume.</summary>
+    public double GameAudioLevel
+    {
+        get => _gameAudioLevel;
+        set
+        {
+            if (SetProperty(ref _gameAudioLevel, Math.Clamp(value, 0, 1)))
+            {
+                OnPropertyChanged(nameof(GameMeterFillWidth));
+                OnPropertyChanged(nameof(GameMeterBrush));
+            }
+        }
+    }
+
+    /// <summary>Displayed game meter level: 0 while muted; the volume position
+    /// while the slider is dragged (or briefly after an unmute flash); otherwise
+    /// the realtime live level scaled by volume.</summary>
+    private double GameMeterLevel => GameMuted ? 0 : _gameVolumeAdjusting || _gameVolumeFlash ? GameAudioVolume : Math.Min(1, AudioLevelMeter.ToDisplay((float)GameAudioLevel) * GameAudioVolume);
+
+    public double GameMeterFillWidth => GameMeterLevel * 288;
+
+    public string GameMeterBrush => GameMeterLevel switch
+    {
+        < 0.6 => "#22c55e",
+        < 0.8 => "#eab308",
+        _ => "#ef4444",
+    };
+
+    public void SetGameVolumeAdjusting(bool adjusting)
+    {
+        if (adjusting)
+            CancelGameVolumeFlash();
+        if (SetProperty(ref _gameVolumeAdjusting, adjusting))
+        {
+            OnPropertyChanged(nameof(GameMeterFillWidth));
+            OnPropertyChanged(nameof(GameMeterBrush));
+        }
+    }
+
+    private void BeginGameVolumeFlash()
+    {
+        _gameVolumeFlash = true;
+        OnPropertyChanged(nameof(GameMeterFillWidth));
+        OnPropertyChanged(nameof(GameMeterBrush));
+        _gameVolumeFlashTimer.Stop();
+        _gameVolumeFlashTimer.Start();
+    }
+
+    private void EndGameVolumeFlash()
+    {
+        _gameVolumeFlashTimer.Stop();
+        if (_gameVolumeFlash)
+        {
+            _gameVolumeFlash = false;
+            OnPropertyChanged(nameof(GameMeterFillWidth));
+            OnPropertyChanged(nameof(GameMeterBrush));
+        }
+    }
+
+    private void CancelGameVolumeFlash()
+    {
+        _gameVolumeFlashTimer.Stop();
+        _gameVolumeFlash = false;
+    }
+
+    /// <summary>Game audio gain (0..1, unity default). Running to 0 mutes; the
+    /// prior level is remembered so the speaker button can restore it.</summary>
+    public double GameAudioVolume
+    {
+        get => _gameVolume;
+        set
+        {
+            var clamped = Math.Clamp(value, 0, 1);
+            if (clamped == 0 && !_gameMuted)
+                _gameVolumeBeforeMute ??= _gameVolume;
+            if (SetProperty(ref _gameVolume, clamped))
+            {
+                var muted = clamped == 0;
+                if (_gameMuted != muted)
+                {
+                    _gameMuted = muted;
+                    OnPropertyChanged(nameof(GameMuted));
+                    OnPropertyChanged(nameof(GameMuteText));
+                }
+                if (!muted)
+                    _gameVolumeBeforeMute = null;
+                OnPropertyChanged(nameof(GameMeterFillWidth));
+                OnPropertyChanged(nameof(GameMeterBrush));
+            }
+        }
+    }
+
+    /// <summary>Read-only: true whenever the volume is 0 (the slider and the
+    /// speaker can never disagree).</summary>
+    public bool GameMuted => _gameMuted;
+
+    public string GameMuteText => GameMuted ? "Unmute" : "Mute";
+
+    private void ToggleGameMute()
+    {
+        if (GameMuted)
+        {
+            GameAudioVolume = _gameVolumeBeforeMute ?? 1.0;
+            BeginGameVolumeFlash();
+        }
+        else
+        {
+            _gameVolumeBeforeMute = GameAudioVolume;
+            GameAudioVolume = 0;
+        }
     }
 
     public bool IsOffline => StreamStatus == StreamStatus.Offline;
     public bool IsLive => StreamStatus == StreamStatus.Streaming;
-    public bool LiveIndicatorVisible => IsLive;
+    public bool IsLivePrivate => IsLive && string.Equals(StreamVisibility, "Private", StringComparison.OrdinalIgnoreCase);
+    public string RecDotBrush => !IsLive ? "#555555" : IsLivePrivate ? "#8f1f1f" : "#e94560";
+    public string RecTextBrush => IsLive ? "#ffffff" : "#888888";
+    public double RecDotOpacity => IsLive ? _recDotPulse : 0.55;
     public bool ShowStartStream => IsOffline;
     public bool ShowChatInactiveMessage => !IsLive;
     public bool ShowEmptySceneHint => ActiveScene != null && ActiveScene.Elements.Count == 0;
@@ -479,7 +678,15 @@ public class MainViewModel : ViewModelBase
     public string StreamVisibility
     {
         get => _streamVisibility;
-        set => SetProperty(ref _streamVisibility, value);
+        set
+        {
+            if (SetProperty(ref _streamVisibility, value))
+            {
+                OnPropertyChanged(nameof(RecDotBrush));
+                OnPropertyChanged(nameof(RecTextBrush));
+                OnPropertyChanged(nameof(IsLivePrivate));
+            }
+        }
     }
 
     public string WindowTitle
@@ -512,12 +719,6 @@ public class MainViewModel : ViewModelBase
         set => SetProperty(ref _liveElapsedText, value);
     }
 
-    public double LivePulseOpacity
-    {
-        get => _livePulseOpacity;
-        set => SetProperty(ref _livePulseOpacity, value);
-    }
-
     // Overlay panels
     public bool IsSettingsOpen
     {
@@ -730,19 +931,19 @@ public class MainViewModel : ViewModelBase
 
     // Commands
     public ICommand AddSceneCommand { get; }
-    public ICommand EditSceneCommand { get; }
-    public ICommand RemoveSceneCommand { get; }
-    public ICommand ToggleSceneVisibilityCommand { get; }
     public ICommand AddSourceCommand { get; }
     public ICommand AddWebcamCommand { get; }
     public ICommand AddImageCommand { get; }
     public ICommand RemoveSourceCommand { get; }
+    public ICommand EditElementCommand { get; }
+    public ICommand ToggleElementVisibilityCommand { get; }
     public ICommand ChangeWebcamCommand { get; }
     public ICommand ShowWebcamCommand { get; }
     public ICommand ChangeCaptureCommand { get; }
     public ICommand RefreshCaptureCommand { get; }
     public ICommand SetBackdropDisplayCommand { get; }
     public ICommand ToggleMicMuteCommand { get; }
+    public ICommand ToggleGameMuteCommand { get; }
     public ICommand OpenMicPickerCommand { get; }
     public ICommand OpenSocialDialogCommand { get; }
     public ICommand StartStreamCommand { get; }
@@ -779,6 +980,9 @@ public class MainViewModel : ViewModelBase
         _volumeFlashTimer = new DispatcherTimer { Interval = TimeSpan.FromMilliseconds(300) };
         _volumeFlashTimer.Tick += (_, _) => EndVolumeFlash();
 
+        _gameVolumeFlashTimer = new DispatcherTimer { Interval = TimeSpan.FromMilliseconds(300) };
+        _gameVolumeFlashTimer.Tick += (_, _) => EndGameVolumeFlash();
+
         _saveDebounce = new DispatcherTimer { Interval = TimeSpan.FromMilliseconds(1500) };
         _saveDebounce.Tick += (_, _) => SaveLayoutNow();
 
@@ -790,13 +994,12 @@ public class MainViewModel : ViewModelBase
         Scenes.CollectionChanged += OnScenesChanged;
 
         AddSceneCommand = new RelayCommand(name => AddScene(name as string ?? string.Empty));
-        EditSceneCommand = new RelayCommand(scene => BeginEditScene(scene as Scene));
-        RemoveSceneCommand = new RelayCommand(scene => RemoveScene(scene as Scene));
-        ToggleSceneVisibilityCommand = new RelayCommand(scene => ToggleSceneVisibility(scene as Scene));
         AddSourceCommand = new RelayCommand(parameter => AddSource(parameter));
         AddWebcamCommand = new RelayCommand(_ => _ = AddWebcamToActiveSceneAsync());
         AddImageCommand = new RelayCommand(_ => AddImage());
         RemoveSourceCommand = new RelayCommand(element => RemoveElement(element as SceneElement));
+        EditElementCommand = new RelayCommand(element => BeginEditElement(element as SceneElement));
+        ToggleElementVisibilityCommand = new RelayCommand(element => ToggleElementVisibility(element as SceneElement));
         ChangeWebcamCommand = new RelayCommand(_ => _ = ChangeWebcamAsync(), _ => CanChangeWebcam);
         ShowWebcamCommand = new RelayCommand(_ => ShowWebcamInActiveScene(), _ => CanShowWebcamInActiveScene);
         OpenSocialDialogCommand = new RelayCommand(_ => OpenSocialDialog());
@@ -804,6 +1007,7 @@ public class MainViewModel : ViewModelBase
         RefreshCaptureCommand = new RelayCommand(_ => RefreshBackdropAutoCapture());
         SetBackdropDisplayCommand = new RelayCommand(display => SetBackdropCapture(display as DisplayInfo));
         ToggleMicMuteCommand = new RelayCommand(_ => ToggleMicMute());
+        ToggleGameMuteCommand = new RelayCommand(_ => ToggleGameMute());
         OpenMicPickerCommand = new RelayCommand(_ => PickMicrophone());
         OpenSettingsCommand = new RelayCommand(_ => ShowOverlay(nameof(IsSettingsOpen), "App Settings"));
         OpenBugCommand = new RelayCommand(_ => ShowOverlay(nameof(IsBugOpen), "Report Bug"));
@@ -832,9 +1036,27 @@ public class MainViewModel : ViewModelBase
 
         _microphoneEnumerator = new WinRtMicrophoneEnumerator();
 
+        _audioMixer = new AudioMixer(
+            new WasapiMicAudioSource(() => MicSourceName),
+            new WasapiLoopbackAudioSource(),
+            message => AppLog.Write(message));
+        _audioMixer.MicLevelChanged += OnMicLevelChanged;
+        _audioMixer.LoopbackLevelChanged += OnLoopbackLevelChanged;
+        _audioMixer.MicConnected += OnMicConnected;
+        _audioMixer.MicFailed += OnMicFailed;
+        _ = StartMicCaptureAsync();
+
         _fullScreenDetector = new Win32FullScreenDetector();
         foreach (var display in _fullScreenDetector.GetDisplays())
             Displays.Add(display);
+
+        _gameAudioDetector = new GameAudioDetector(
+            () => _fullScreenDetector.GetForegroundFullScreenMonitorIndex(),
+            () => (float)GameAudioLevel);
+        _gameAudioDetector.IsGameAudioActiveChanged += OnGameAudioActiveChanged;
+        _gameAudioTimer = new DispatcherTimer { Interval = TimeSpan.FromMilliseconds(250) };
+        _gameAudioTimer.Tick += OnGameAudioPollTick;
+        _gameAudioTimer.Start();
         _screenCaptureFactory = new ScreenCaptureSourceFactory(
             () => new WindowInteropHelper(System.Windows.Application.Current?.MainWindow).Handle);
         _screenCaptureManager = new ScreenCaptureManager(
@@ -844,6 +1066,18 @@ public class MainViewModel : ViewModelBase
         _screenCaptureManager.CaptureFailed += (key, message) =>
             AppLog.Write($"ScreenCaptureManager: capture '{key}' failed: {message}");
 
+        _rtmpUrlProvider = () => null; // TASK 5: the reusable stream's ingest URL
+        _framePump = new FramePump(
+            sceneProvider: () => ActiveScene,
+            frameResolver: ResolveOutputFrame,
+            compositorOptions: BuildCompositorOptions,
+            encoderOptions: BuildEncoderOptions,
+            encoderFactory: () => new FfmpegEncoder(new FfmpegLocator()),
+            log: message => AppLog.Write(message),
+            socialBar: () => (_socialBarFrame, _socials?.BarPosition ?? SocialBarPosition.Bottom));
+        _framePump.Failed += OnFramePumpFailed;
+        _framePump.HealthUpdated += OnFramePumpHealthUpdated;
+
         LoadLayout();
         _ = LoadSavedSessionAsync();
         AppLog.Write("MainViewModel ctor end");
@@ -935,6 +1169,8 @@ public class MainViewModel : ViewModelBase
         ReacquireWebcam();
         ReacquireScreenCaptures();
         _socials = _layoutStore.Socials;
+        RenderSocialBarFrame();
+        HealFediverseSoftwareInBackground();
         OnPropertyChanged(nameof(HasSocials));
         OnPropertyChanged(nameof(SocialBarVisible));
         OnPropertyChanged(nameof(SocialBarDotBrush));
@@ -1156,6 +1392,9 @@ public class MainViewModel : ViewModelBase
     {
         _saveDebounce?.Stop();
         SaveLayoutNow();
+        _gameAudioTimer.Stop();
+        _audioMixer.Dispose();
+        _framePump.Dispose();
         _cameraManager.Dispose();
         _screenCaptureManager.Dispose();
         _layoutStore.Dispose();
@@ -1283,26 +1522,16 @@ public class MainViewModel : ViewModelBase
         ActiveScene = scene;
     }
 
-    private void BeginEditScene(Scene? scene)
+    private void BeginEditElement(SceneElement? element)
     {
-        if (scene == null) return;
-        scene.IsEditing = true;
+        if (element == null) return;
+        element.IsEditing = true;
     }
 
-    private void ToggleSceneVisibility(Scene? scene)
+    private void ToggleElementVisibility(SceneElement? element)
     {
-        if (scene == null) return;
-        scene.IsHidden = !scene.IsHidden;
-        if (scene.IsHidden && ActiveScene == scene)
-            ActiveScene = Scenes.FirstOrDefault(s => !s.IsHidden);
-    }
-
-    private void RemoveScene(Scene? scene)
-    {
-        if (scene == null) return;
-        Scenes.Remove(scene);
-        if (ActiveScene == scene)
-            ActiveScene = Scenes.FirstOrDefault();
+        if (element == null) return;
+        element.IsVisible = !element.IsVisible;
     }
 
     private void AddSource(object? parameter)
@@ -1345,15 +1574,30 @@ public class MainViewModel : ViewModelBase
             return;
         }
 
-        var count = scene.Elements.OfType<Source>().Count(s => s.Type == sourceType);
-        var name = count == 0 ? baseName : $"{baseName} {count + 1}";
-
-        scene.Elements.Add(new Source { Name = name, Type = sourceType });
+        scene.Elements.Add(new Source { Name = NextSourceName(scene, baseName), Type = sourceType });
         OnPropertyChanged(nameof(ShowEmptySceneHint));
         OnPropertyChanged(nameof(ShowSourcesEmptyHint));
         UpdateActiveBackground();
     }
 
+    // Duplicate resource names get an incrementing suffix with no space: Image,
+    // Image2, Image3… The next free number is derived from the names actually in
+    // the scene, so deleting a middle resource never collides with a survivor.
+    private static string NextSourceName(Scene scene, string baseName)
+    {
+        var taken = scene.Elements.OfType<Source>()
+            .Select(s => s.Name)
+            .Where(n => string.Equals(n, baseName, StringComparison.OrdinalIgnoreCase)
+                || (n.Length > baseName.Length
+                    && n.StartsWith(baseName, StringComparison.OrdinalIgnoreCase)
+                    && int.TryParse(n.Substring(baseName.Length), out _)))
+            .ToHashSet(StringComparer.OrdinalIgnoreCase);
+        if (!taken.Contains(baseName)) return baseName;
+        for (var i = 2; ; i++)
+            if (!taken.Contains($"{baseName}{i}"))
+                return $"{baseName}{i}";
+    }
+
     // Adds the webcam to the active scene. The creator ALWAYS picks from the
     // cameras Windows has registered — never silently resurrects the previous
     // camera (which is what happened after deleting one scene's webcam while
@@ -1568,10 +1812,7 @@ public class MainViewModel : ViewModelBase
         var scene = ActiveScene;
         if (scene == null || string.IsNullOrWhiteSpace(assetId)) return;
 
-        var count = scene.Elements.OfType<Source>().Count(s => s.Type == SourceType.Image);
-        var name = count == 0 ? "Image" : $"Image {count + 1}";
-
-        var source = new Source { Name = name, Type = SourceType.Image, AssetId = assetId };
+        var source = new Source { Name = NextSourceName(scene, "Image"), Type = SourceType.Image, AssetId = assetId };
 
         var image = ImageCache.Get(assetId);
         if (image != null)
@@ -1725,6 +1966,8 @@ public class MainViewModel : ViewModelBase
                 ? "ytLlive"
                 : $"{dialog.StreamTitle} — ytLlive";
             StreamStatus = StreamStatus.Streaming;
+            ResetHealth(StreamStatus.Streaming);
+            _ = _framePump.StartAsync(); // never throws; failures log + surface via Failed
         }
     }
 
@@ -1732,6 +1975,10 @@ public class MainViewModel : ViewModelBase
     {
         StreamStatus = StreamStatus.Offline;
         WindowTitle = "ytLlive";
+        ResetHealth(StreamStatus.Offline);
+        // Audio capture is always-on (preview monitoring); only the frame pump
+        // and the session stop here.
+        _ = _framePump.StopAsync();
         // Graceful end completes the session = signs out (the DPAPI token is
         // cleared so the next Start Stream requires a fresh sign-in). A crash
         // never runs this, so the token survives and the creator stays signed in.
@@ -1742,6 +1989,170 @@ public class MainViewModel : ViewModelBase
         AppLog.Write("Stream ended; session signed out");
     }
 
+    private void OnMicLevelChanged(float level)
+    {
+        // NAudio raises on its capture thread; marshal to the UI thread so the
+        // meter binding updates safely.
+        var dispatcher = System.Windows.Application.Current?.Dispatcher;
+        if (dispatcher != null && !dispatcher.CheckAccess())
+            dispatcher.BeginInvoke(() => AudioLevel = level);
+        else
+            AudioLevel = level;
+    }
+
+    private void OnLoopbackLevelChanged(float level)
+    {
+        var dispatcher = System.Windows.Application.Current?.Dispatcher;
+        if (dispatcher != null && !dispatcher.CheckAccess())
+            dispatcher.BeginInvoke(() => GameAudioLevel = level);
+        else
+            GameAudioLevel = level;
+    }
+
+    private void OnMicConnected()
+    {
+        var dispatcher = System.Windows.Application.Current?.Dispatcher;
+        if (dispatcher != null && !dispatcher.CheckAccess())
+            dispatcher.BeginInvoke(() => MicStatus = MicStatus.Connected);
+        else
+            MicStatus = MicStatus.Connected;
+    }
+
+    private void OnMicFailed(Exception ex)
+    {
+        // The mixer logs the failure detail; here we only flip the dot to yellow.
+        var dispatcher = System.Windows.Application.Current?.Dispatcher;
+        if (dispatcher != null && !dispatcher.CheckAccess())
+            dispatcher.BeginInvoke(() => MicStatus = MicStatus.Problem);
+        else
+            MicStatus = MicStatus.Problem;
+    }
+
+    /// <summary>Starts capture once at startup: with no mic device present the
+    /// dot stays red and capture never starts; otherwise the mixer starts and
+    /// raises MicConnected (green) or MicFailed (yellow).</summary>
+    private async Task StartMicCaptureAsync()
+    {
+        try
+        {
+            var mics = await _microphoneEnumerator.GetMicrophonesAsync();
+            if (mics.Count == 0)
+            {
+                MicStatus = MicStatus.NotConnected;
+                AppLog.Write("Mic: no capture devices found — mic capture not started");
+                return;
+            }
+            _audioMixer.Start();
+        }
+        catch (Exception ex)
+        {
+            AppLog.Write($"Mic: device check failed: {ex.Message}");
+        }
+    }
+
+    private void OnGameAudioActiveChanged(bool active) => IsGameAudioBarVisible = active;
+
+    private void OnGameAudioPollTick(object? sender, EventArgs e)
+    {
+        try
+        {
+            _gameAudioDetector.Poll();
+        }
+        catch (Exception ex)
+        {
+            AppLog.Write($"Game audio detection failed: {ex.Message}");
+        }
+    }
+
+    // Scene-element → latest frame, for the live compositor. The map mirrors the
+    // preview: webcam by DeviceId, live captures (the backdrop) by CaptureKey,
+    // images/background by AssetId. A null frame leaves the element transparent.
+    private VideoFrame? ResolveOutputFrame(SceneElement element)
+    {
+        return element switch
+        {
+            WebcamSceneConfig webcam => _cameraManager.GetLatestFrame(webcam.WebcamId),
+            Source { IsLiveCapture: true, CaptureKey: not null } live => _screenCaptureManager.GetLatestFrame(live.CaptureKey),
+            Source { AssetId: not null } image => StaticPixelCache.Get(image.AssetId),
+            _ => null,
+        };
+    }
+
+    // The tier's crop rect over the 1920x1080 master, integer-aligned (the VM's
+    // OutputRect* are doubles — the vertical 607.5 half-pixel crop rounds to 608).
+    private CompositorOptions BuildCompositorOptions()
+    {
+        var quality = SelectedQuality;
+        return new CompositorOptions
+        {
+            SourceRectX = (int)Math.Round(OutputRectX),
+            SourceRectY = (int)Math.Round(OutputRectY),
+            SourceRectWidth = (int)Math.Round(OutputRectWidth),
+            SourceRectHeight = (int)Math.Round(OutputRectHeight),
+            OutputWidth = quality.Width,
+            OutputHeight = quality.Height,
+        };
+    }
+
+    // Full encoder options for the current tier, or null when no RTMP URL is
+    // available — the pump then skips the encoder entirely (TASK 5 fills the seam).
+    private EncoderOptions? BuildEncoderOptions()
+    {
+        var url = _rtmpUrlProvider();
+        if (string.IsNullOrWhiteSpace(url)) return null;
+        var quality = SelectedQuality;
+        return new EncoderOptions
+        {
+            RtmpUrl = url,
+            Width = quality.Width,
+            Height = quality.Height,
+            Fps = quality.Fps,
+            BitrateKbps = (int)Math.Round(quality.Bitrate * 1000),
+        };
+    }
+
+    private void OnFramePumpFailed(object? sender, string message)
+    {
+        AppLog.Write($"Frame pump failed: {message}");
+        if (IsLive) StreamStatus = StreamStatus.Error;
+    }
+
+    // TASK 4 ship step 6: the encoder's parsed health (bitrate/FPS/dropped/
+    // duration) lands in the bottom bar. The stderr loop raises on a background
+    // thread — marshal to the UI thread like the audio level handlers.
+    private void OnFramePumpHealthUpdated(object? sender, StreamHealth health)
+    {
+        var dispatcher = System.Windows.Application.Current?.Dispatcher;
+        if (dispatcher != null && !dispatcher.CheckAccess())
+            dispatcher.BeginInvoke(() => ApplyHealth(health));
+        else
+            ApplyHealth(health);
+    }
+
+    private void ApplyHealth(StreamHealth health)
+    {
+        CurrentHealth.Status = health.Status;
+        CurrentHealth.CurrentBitrate = health.CurrentBitrate;
+        CurrentHealth.FPS = health.FPS;
+        CurrentHealth.DroppedFrames = health.DroppedFrames;
+        CurrentHealth.StreamDuration = health.StreamDuration;
+        CurrentHealth.LastError = health.LastError;
+        CurrentHealth.HealthMessage = health.HealthMessage;
+        OnPropertyChanged(nameof(CurrentHealth));
+    }
+
+    // Keeps the bottom-bar stats honest across sessions: dropped frames and the
+    // elapsed duration must not linger from a previous go-live (bitrate/FPS stay
+    // on the tier's targets — ApplyStreamQuality sets them on pick).
+    private void ResetHealth(StreamStatus status)
+    {
+        CurrentHealth.Status = status;
+        CurrentHealth.DroppedFrames = 0;
+        CurrentHealth.StreamDuration = TimeSpan.Zero;
+        CurrentHealth.LastError = null;
+        OnPropertyChanged(nameof(CurrentHealth));
+    }
+
     private void UpdateLiveVisuals()
     {
         var live = IsLive;
@@ -1753,7 +2164,8 @@ public class MainViewModel : ViewModelBase
         {
             _liveElapsed = TimeSpan.Zero;
             LiveElapsedText = "00:00:00";
-            LivePulseOpacity = 1.0;
+            _recDotPulse = 1.0;
+            OnPropertyChanged(nameof(RecDotOpacity));
             _liveTimer.Start();
             if (BrandFlashEnabled) StartBrandFlashTimer();
         }
@@ -1764,7 +2176,8 @@ public class MainViewModel : ViewModelBase
             _brandFlashOffTimer.Stop();
             BrandFlashActive = false;
             LiveElapsedText = "00:00:00";
-            LivePulseOpacity = 1.0;
+            _recDotPulse = 1.0;
+            OnPropertyChanged(nameof(RecDotOpacity));
         }
     }
 
@@ -1797,11 +2210,89 @@ public class MainViewModel : ViewModelBase
     {
         _liveElapsed = _liveElapsed.Add(TimeSpan.FromSeconds(1));
         LiveElapsedText = _liveElapsed.ToString(@"hh\:mm\:ss");
-        LivePulseOpacity = LivePulseOpacity > 0.5 ? 0.35 : 1.0;
+        _recDotPulse = _recDotPulse > 0.5 ? 0.35 : 1.0;
+        OnPropertyChanged(nameof(RecDotOpacity));
     }
 
     // ─── Social bar ───
 
+    /// <summary>
+    /// Resolves a missing nodeinfo software name (mastodon, peertube, ...) for every
+    /// fediverse entry that doesn't have one, so the bar shows the instance's real
+    /// logo instead of the generic fediverse glyph. Best-effort: a failed resolution
+    /// leaves the glyph untouched. Returns handle → software for what was resolved —
+    /// the caller applies + persists (the app hops to the dispatcher; a test applies
+    /// directly).
+    /// </summary>
+    public static async Task<Dictionary<string, string>> HealFediverseSoftwareAsync(
+        SocialsConfig socials,
+        ISocialValidator validator,
+        Action<string>? log = null)
+    {
+        var resolved = new Dictionary<string, string>();
+        if (socials == null || validator == null) return resolved;
+        foreach (var entry in socials.Entries)
+        {
+            if (entry.Service != SocialService.Fediverse
+                || !string.IsNullOrWhiteSpace(entry.FediverseSoftware))
+                continue;
+            if (!SocialServiceIcons.TryParseFediverse(entry.Handle, out _, out var domain))
+                continue;
+            var software = await validator.ResolveFediverseSoftwareAsync(
+                domain, System.Threading.CancellationToken.None);
+            if (string.IsNullOrWhiteSpace(software)) continue;
+            resolved[entry.Handle] = software;
+            log?.Invoke($"Socials heal: {entry.Handle} → {software}");
+        }
+        return resolved;
+    }
+
+    /// <summary>Runs the heal off the UI thread and applies + saves any result.</summary>
+    private void HealFediverseSoftwareInBackground()
+    {
+        var socials = _socials;
+        if (socials == null) return;
+        _ = Task.Run(async () =>
+        {
+            try
+            {
+                var resolved = await HealFediverseSoftwareAsync(
+                    socials, _socialValidator, m => AppLog.Write(m));
+                if (resolved.Count == 0) return;
+                await Application.Current.Dispatcher.InvokeAsync(() =>
+                {
+                    var current = _socials;
+                    if (current == null) return;
+                    var applied = false;
+                    foreach (var entry in current.Entries)
+                    {
+                        if (!resolved.TryGetValue(entry.Handle, out var software)) continue;
+                        if (entry.FediverseSoftware == software) continue;
+                        entry.FediverseSoftware = software;
+                        applied = true;
+                    }
+                    if (applied) NotifySocialsChanged(); // re-renders the bar + saves
+                });
+            }
+            catch (Exception ex)
+            {
+                AppLog.Write($"Socials heal failed: {ex.Message}");
+            }
+        });
+    }
+
+    /// <summary>
+    /// Re-rasterizes the social bar strip the output compositor overlays. UI thread
+    /// only (WPF rendering); the resulting frame is immutable, so the frame pump may
+    /// read it from its own thread. Null when the bar is off or empty.
+    /// </summary>
+    private void RenderSocialBarFrame()
+    {
+        _socialBarFrame = _socials != null && _socials.BarEnabled
+            ? SocialBarRenderer.Render(_socials.Entries)
+            : null;
+    }
+
     /// <summary>
     /// Opens the Social Media Site Promotion dialog (6 slots, sign-in gate,
     /// validation). On save the working copy replaces <see cref="_socials"/>.
@@ -1825,13 +2316,14 @@ public class MainViewModel : ViewModelBase
 
     private void NotifySocialsChanged()
     {
+        RenderSocialBarFrame();
         OnPropertyChanged(nameof(HasSocials));
         OnPropertyChanged(nameof(SocialBarVisible));
         OnPropertyChanged(nameof(SocialBarDotBrush));
         ScheduleSave();
     }
 
-    /// <summary>Drag release snaps the bar to the closest edge; called by the preview drag.</summary>
+    /// <summary>Sets the bar's edge; called by the preview click-toggle.</summary>
     public void SetSocialBarPosition(SocialBarPosition position)
     {
         if (_socials == null || _socials.BarPosition == position) return;
@@ -1840,6 +2332,12 @@ public class MainViewModel : ViewModelBase
         ScheduleSave();
     }
 
+    /// <summary>Preview click flips the bar top ⇄ bottom (KISS — no drag math).</summary>
+    public void ToggleSocialBarPosition()
+        => SetSocialBarPosition(_socials?.BarPosition == SocialBarPosition.Top
+            ? SocialBarPosition.Bottom
+            : SocialBarPosition.Top);
+
     /// <summary>Signs out of YouTube (the delete-the-YouTube-slot action in the dialog).</summary>
     private async Task SignOutYouTubeAsync()
     {

ai.md

@@ -91,7 +91,7 @@ C# / WPF (.NET 8) following MVVM:
 |------|------|
 | `Models/` | Plain data types — Scene, Source (incl. `ClipShape`, `IsMirrored`, `VideoImageSource`), QualityOption, StreamConfig, StreamHealth, YouTubeChannel, ChatMessage, **Socials (`SocialService` enum + `SocialEntry`/`SocialsConfig` + `SocialServiceIcons`) — the social bar** |
 | `ViewModels/` | MainViewModel — exposes collections + commands for the UI; GoLiveViewModel, ReuseImageViewModel, CameraPickerViewModel, **SocialsDialogViewModel** |
-| `Services/` | YouTube OAuth2, stream/broadcast management, live chat polling, LayoutStore (SQLite), **SocialValidator (`ISocialValidator` seam + `HttpSocialValidator` default)**, **webcam: `VideoFrame` seam + `CameraDeviceInfo`/`ICameraEnumerator`/`ICameraFrameSource` interfaces + `MediaCaptureCameraEnumerator`/`MediaCaptureFrameSource` (WinRT) + `CameraManager`**, **screen capture: `IFullScreenDetector`/`Win32FullScreenDetector` + `IScreenCaptureSource`/`ScreenCaptureFrameSource` (WinRT GraphicsCapture) + `ScreenCaptureManager` + `ScreenCaptureSourceFactory` + `Direct3D11Helper`/`CaptureInterop` (COM bridges)** |
+| `Services/` | YouTube OAuth2, stream/broadcast management, live chat polling, LayoutStore (SQLite), **SocialValidator (`ISocialValidator` seam + `HttpSocialValidator` default)**, **webcam: `VideoFrame` seam + `CameraDeviceInfo`/`ICameraEnumerator`/`ICameraFrameSource` interfaces + `MediaCaptureCameraEnumerator`/`MediaCaptureFrameSource` (WinRT) + `CameraManager`**, **screen capture: `IFullScreenDetector`/`Win32FullScreenDetector` + `IScreenCaptureSource`/`ScreenCaptureFrameSource` (WinRT GraphicsCapture) + `ScreenCaptureManager` + `ScreenCaptureSourceFactory` + `Direct3D11Helper`/`CaptureInterop` (COM bridges)**, **compositor: `SceneCompositor` + `CompositorOptions` + pure `StretchMath` + `StaticPixelCache` (see "Scene compositor")**, **audio: `IAudioSource` seam + `WasapiLoopbackAudioSource`/`WasapiMicAudioSource` (NAudio WASAPI) + `AudioMixer` + pure `AudioLevelMeter`/`WaveToFloat` + game bar: `IGameAudioDetector`/`GameAudioHysteresis`/`GameAudioDetector` (see "Live audio capture")**, **encoder: `IFfmpegEncoder`/`FfmpegEncoder` + `IEncoderProcess`/`FfmpegEncoderProcess` + `IFfmpegLocator`/`FfmpegLocator` + pure `FfmpegArgs`/`FfmpegProgressParser`/`FfmpegEncoderPicker` + the `FramePump` frame producer (see "Live encoder" + "Live frame pipeline")** |
 | `Helpers/` | ViewModelBase (INotifyPropertyChanged), RelayCommand, ImageCache, AppLog (file logger), FocusPreservingListBox, OAuthCredentials, **TokenStore (DPAPI session persistence)**, visibility converters |
 | `Themes/` | `Controls.xaml` — the single dark-theme source, merged once in `App.xaml` (see `Themes/index.md`) |
 | `MainWindow.xaml` | Dark theme; layout: top bar (controls), center (preview), left (scenes/sources), right (chat), bottom (health) |
@@ -100,7 +100,7 @@ C# / WPF (.NET 8) following MVVM:
 
 - `ViewModelBase.SetProperty<T>()` for property change notifications
 - `RelayCommand` for all button actions; commands gate on state (e.g. Start only when Offline). **Typed `CommandParameter`s — no stringly-typed command tokens:** menu items that pick a source type pass the enum value itself (`CommandParameter="{x:Static models:SourceType.DisplayCapture}"`), so a typo breaks the build instead of silently adding an Image; `AddSource` still falls back to `Enum.TryParse<SourceType>(..., true)` for safety. The webcam item is its own `AddWebcamCommand` (it greys out via `CanAddWebcamToActiveScene` and isn't a `SourceType` — webcams are `WebcamSceneConfig`, not `Source` rows)
-- **Audio is KISS by rule** — the whole of audio is *one knob*: **desktop/game audio is automatic** (WASAPI loopback from the default output at unity, zero UI — "it just is"); the **mic is the creator's only audio control** — sound meter + mute button + volume slider (`MicVolume`, defaults to 0.8) all sit together on the footer's top line, CENTERED beneath the preview panel. Meter: 288px, muted slate track (`#3a3b52`) with ruler graduations and muted yellow/red zone tints at 60%/80%; fill = green → yellow → red via `MeterFillWidth`/`MeterBrush`; the meter is a **READ-ONLY realtime level display** — it shows the live input level scaled by the volume (raising the volume moves ambient noise up the bar), NOT the volume setting: the fill is `Math.Min(1, AudioLevel * MicVolume)` (`AudioLevel` is fed by the audio mixer once capture lands, 0 with no input) and 0 while muted. While the volume slider is being dragged the bar previews the slider position (`SetVolumeAdjusting`, from `PreviewMouseLeftButtonDown/Up` + `LostMouseCapture` handlers) so the creator sees where they're setting it; on release it returns to the live level — with no input it bounces back to 0, exactly as it does today. Clicking the meter does nothing; **clicking the MIC label opens the mic picker** (`OpenMicPickerCommand`), and the picked voice source name (`MicSourceName`) is shown left-justified INSIDE the meter bar (FontSize 10, ellipsized to the bar) — the fill runs at 75% opacity so the text and the ruler markings stay visible through it. Mute (`ToggleMicMuteCommand`/`MicMuted`) is a plain clickable speaker icon (`MicSpeaker_MouseLeftButtonUp` code-behind handler — not a Button, `Stretch="Uniform"` so the glyph is never clipped) that swaps to a red do-not-symbol (slashed speaker) when muted. **The slider and the speaker can never disagree:** `MicMuted` is read-only, derived from `MicVolume == 0` — sliding the volume off flips the speaker to muted (storing the prior level in `_volumeBeforeMute`), sliding it up from 0 clears the mute indicator (and the stored level); the speaker button just runs the volume to 0 or restores it (default 0.8 if unknown). Muting zeroes the meter; **unmuting flashes the meter to the restored position for ~300ms** (`BeginVolumeFlash`/`EndVolumeFlash` on a DispatcherTimer, cancelled if the slider is grabbed) before it returns to the live level. Line 2 of the footer holds everything else: stream stats (bitrate/fps/dropped/duration/health) on the left, quality dropdown + gear on the right. The slider is a slim dimensional style in `Themes/Controls.xaml` (gradient track, beveled green fill on a 5px pill, gloss-sphere thumb with drop shadow — deliberately NOT flat). No device pickers (never show device names — no "install a device you didn't know existed"), no filter stacks, no monitoring, no routing — OBS's confusion (dynamic mixer, unintuitive names, four required filters) is deliberately absent. A production-ready mic chain (high-pass → noise gate → compressor) will be applied invisibly in the mixer, unconfigurable. Capture runs only while live (privacy indicator stays off otherwise). Capture pipeline = `IAudioSource` seam + NAudio `WasapiCapture`/`WasapiLoopbackCapture` + `AudioMixer` (pending — the UI is in place now). The connected account's avatar/name shows in the top bar next to Start Stream (`AccountAvatarUrl`/`AccountDisplayName` via `SyncConnectedAccount`), so the creator always sees WHICH account will go live.
+- **Audio is KISS by rule** — the whole of audio is *one knob*: **desktop/game audio is automatic** (WASAPI loopback from the default output at unity, zero UI — "it just is"); the **mic is the creator's only audio control** — sound meter + mute button + volume slider (`MicVolume`, defaults to 0.8) all sit together on the footer's top line, CENTERED beneath the preview panel. Meter: 288px, muted slate track (`#3a3b52`) with ruler graduations and muted yellow/red zone tints at 60%/80%; fill = green → yellow → red via `MeterFillWidth`/`MeterBrush`; the meter is a **READ-ONLY realtime level display** — it shows the live input level scaled by the volume (raising the volume moves ambient noise up the bar), NOT the volume setting: the fill is `Math.Min(1, AudioLevelMeter.ToDisplay(AudioLevel) * MicVolume)` — `ToDisplay` maps the raw linear RMS onto a −60..0 dBFS display scale, because real speech sits around −40..−20 dBFS (0.01..0.1 linear) which would leave a flat scale dead (`AudioLevel` is fed by the audio mixer once capture lands, 0 with no input) and 0 while muted. While the volume slider is being dragged the bar previews the slider position (`SetVolumeAdjusting`, from `PreviewMouseLeftButtonDown/Up` + `LostMouseCapture` handlers) so the creator sees where they're setting it; on release it returns to the live level — with no input it bounces back to 0, exactly as it does today. Clicking the meter does nothing; **clicking the MIC label opens the mic picker** (`OpenMicPickerCommand`), and the picked voice source name (`MicSourceName`) is shown left-justified INSIDE the meter bar (FontSize 10, ellipsized to the bar) — the fill runs at 75% opacity so the text and the ruler markings stay visible through it. Mute (`ToggleMicMuteCommand`/`MicMuted`) is a plain clickable speaker icon (`MicSpeaker_MouseLeftButtonUp` code-behind handler — not a Button, `Stretch="Uniform"` so the glyph is never clipped) that swaps to a red do-not-symbol (slashed speaker) when muted. **The slider and the speaker can never disagree:** `MicMuted` is read-only, derived from `MicVolume == 0` — sliding the volume off flips the speaker to muted (storing the prior level in `_volumeBeforeMute`), sliding it up from 0 clears the mute indicator (and the stored level); the speaker button just runs the volume to 0 or restores it (default 0.8 if unknown). Muting zeroes the meter; **unmuting flashes the meter to the restored position for ~300ms** (`BeginVolumeFlash`/`EndVolumeFlash` on a DispatcherTimer, cancelled if the slider is grabbed) before it returns to the live level. Line 2 of the footer holds everything else: stream stats (bitrate/fps/dropped/duration/health) on the left, quality dropdown + gear on the right. The slider is a slim dimensional style in `Themes/Controls.xaml` (gradient track, beveled green fill on a 5px pill, gloss-sphere thumb with drop shadow — deliberately NOT flat). No device pickers (never show device names — no "install a device you didn't know existed"), no filter stacks, no monitoring, no routing — OBS's confusion (dynamic mixer, unintuitive names, four required filters) is deliberately absent. A production-ready mic chain (high-pass → noise gate → compressor) will be applied invisibly in the mixer, unconfigurable. Capture runs only while live (privacy indicator stays off otherwise). Capture pipeline = `IAudioSource` seam + NAudio `WasapiCapture`/`WasapiLoopbackCapture` + `AudioMixer` (pending — the UI is in place now). **Mic mute icon (2026-08-13):** a second 16px clickable glyph — a microphone, red + slash when muted — sits **between the meter and the speaker** (both mutes adjacent, spacing between the icons) and reuses the same `MicSpeaker_MouseLeftButtonUp` → `ToggleMicMuteCommand` handler. **REC sign (2026-08-13):** the top-center indicator is an **always-visible REC chip** (`RecDotBrush`/`RecTextBrush`/`RecDotOpacity`/`IsLivePrivate`) — dark gray dot + dim "REC" offline, bright red (#e94560) while live, darker red (#8f1f1f) when live with a **private** stream (driven by the dialog's chosen `StreamVisibility`; the stream service still forces public — see TASK 4 ship step 7); the dot pulses while live, and the elapsed timer shows only when live. The connected account's avatar/name shows in the top bar next to Start Stream (`AccountAvatarUrl`/`AccountDisplayName` via `SyncConnectedAccount`), so the creator always sees WHICH account will go live.
 - ViewModels are constructed in XAML (`<vm:MainViewModel/>` as DataContext)
 - Services are currently instantiated in MainViewModel's constructor — no DI container yet
 - Layout persists to SQLite (`Microsoft.Data.Sqlite`); scenes/sources/asset bytes stored in the DB, asset identity is a SHA-256 content hash (1:M reuse, no file paths — assets are always available)
@@ -114,7 +114,7 @@ C# / WPF (.NET 8) following MVVM:
 - `Helpers/OAuthCredentials.cs` contains the real ClientId/ClientSecret. Auth is complete and the session **persists via Windows DPAPI** (`Helpers/TokenStore.cs` → `%APPDATA%\ytLlive\ytLlive.auth`, CurrentUser scope), reloaded best-effort at startup with a proactive refresh of a near-expiry access token. Sign-in/Change Account lives **inside the Start Stream dialog** (two-state flow — no separate Connect button). A **graceful End Livestream signs out**: `StopStream()` clears the session + token, so the next go-live needs a fresh sign-in; a crash never runs End, so the token survives and the creator stays signed in. `YouTubeAuthService` takes an optional `HttpClient` + `sessionChanged` callback (test seam + save hook; services are still constructed in `MainViewModel`)
 - Scene/source/asset layout + the social bar persist (SQLite, schema v8); the OAuth session persists (DPAPI); the paid-unlock state does not (yet — itch.io key verification pending)
 - `YouTubeStreamService` uses hardcoded `1080p`/`60fps` and per-broadcast streams — must switch to the v3 `variable` reusable stream
-- Webcam capture is shipped (milestone 1); the live desktop/game backdrop is shipped (ship task #1); **the output compositor (TASK 4 ship step 1) is SHIPPED**, **the FFmpeg locator (TASK 4 ship step 2) is SHIPPED** — full plan in `TASKS.md`; the encoder subprocess + RTMP push, audio capture, and the frame-pipeline wiring follow (each its own PR)
+- Webcam capture is shipped (milestone 1); the live desktop/game backdrop is shipped (ship task #1); **the output compositor (TASK 4 ship step 1) is SHIPPED**, **the FFmpeg locator (TASK 4 ship step 2) is SHIPPED**, **the encoder + RTMP push (TASK 4 ship step 3) is SHIPPED**, **WASAPI audio capture (TASK 4 ship step 4) is SHIPPED** — full plan in `TASKS.md`; the frame-pipeline wiring follows (its own PR)
 - `StreamConfig` defaults (`TargetBitrate=6000`, `Resolution="1920x1080"`) are stale — the live dropdown drives `StreamHealth.CurrentBitrate`/`FPS` instead
 
 ### Screen backdrop capture (TASK 3 ship task #1)
@@ -180,6 +180,14 @@ instead of a normal draggable source.
 - **Known v1 limits:** full-desktop captures are CPU-copied at native resolution (GPU downscale = encoder
   task); window capture (`window:<hwnd>`) and multi-monitor live re-targeting beyond the auto-detected
   game are behind the picker; picker-based captures don't survive reload.
+- **Focus-loss capture lag (known OS limit, NOT an in-app throttle — deferred):** when the app window loses
+  focus the preview visibly slows (mouse-movement lag). Nothing in the repo checks focus to slow capture —
+  the only focus hooks (`NoteBackgroundWindow`/`RefreshBackdropAutoCapture`) re-target the backdrop, never
+  pace it. The lag is inherited: `Windows.Graphics.Capture` is content-driven and DWM/OS-throttled while the
+  app is in the background (worse under a full-screen game on 24H2/26100), GPU readback
+  (`CreateCopyFromSurfaceAsync`) contends with the foreground game, the source's one-in-flight `_framePending`
+  gate drops frames during stalls, and the manager's `DispatcherPriority.Render` copies only run as fast as
+  WPF presents the window. Recorded 2026-08-13; no mitigation attempted yet (deferred by user decision).
 - **GPU posture:** same as webcam — CPU frames, WPF hardware-presents; D3DImage GPU compositing deferred
   to the encoder task.
 - **Preview watermark:** the "Preview" placeholder hides while a backdrop renders —
@@ -330,11 +338,124 @@ const). Constructor-injected search dirs / tools dir / downloader (`Func<string,
 Task<byte[]>>`) keep it hermetic: tests fake the network with a real in-memory zip. Constructed in the
 encoder step (not yet — this PR ships the seam + impl + tests only).
 
-### Social bar (TASK 14 — shipped 2026-08-12, plan in TASKS.md)
+### Live encoder + RTMP push (TASK 4 ship step 3 — shipped 2026-08-12, plan in TASKS.md)
+
+The encoder is a **thin orchestrator over `ffmpeg.exe`** — no H.264/AAC code in the app. It spawns the
+subprocess (path from `IFfmpegLocator`), feeds raw BGRA master frames into stdin, and parses `-stats`
+stderr lines into `StreamHealth` (bitrate/FPS/duration, dropped-from-frame-count). `FfmpegEncoder`
+(`IFfmpegEncoder` seam) holds: `StartAsync` (locate → probe `-encoders` → spawn → stderr loop),
+`SubmitFrameAsync` (serialized stdin writes under `SemaphoreSlim`), `StopAsync` (stdin EOF → ffmpeg
+finalizes + exits by itself; a 10s watchdog kills it), `Dispose` (force-kill + wait), and the
+`HealthUpdated`/`ProcessFailed` events. **Pattern:** the encoder never touches `Process` — it drives the
+`IEncoderProcess` seam (`FfmpegEncoderProcess` wraps the real `Process`, redirected stdin/stdout/stderr
++ exit control); a `Func<IEncoderProcess>` factory + the locator are constructor-injected, so the
+integration test fakes the whole subprocess (probe + encoder) with a Channel-backed `TextReader` whose
+`Complete()` is EOF (`null`), never a `ChannelClosedException`.
+
+**Decisions (locked):** args are pure (`FfmpegArgs.Build`, no string building in the encoder):
+`-re -f rawvideo -pix_fmt bgra -video_size WxH -framerate FPS -i pipe:0` + a **silent placeholder
+`-f lavfi -i anullsrc`** track (WASAPI capture, ship step 4, replaces it) + `-c:v <enc> -b:v K
+-maxrate K -bufsize 2K` + **`-g fps×4 -keyint_min fps×4 -sc_threshold 0 -bf 0 -pix_fmt yuv420p`**
+(≤4s keyframes, 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):
+NVENC → QSV → AMF → OpenH264 fallback, **never libx264** (GPL; see Licensing). `EncoderOptions.VideoEncoder`
+forces one and skips the probe. `EncoderOptions` also carries W×H/FPS/bitrate from the quality tier and
+`GopSize` = FPS×4. Constructed by `MainViewModel` since ship step 5 (`new FfmpegEncoder(new FfmpegLocator())`),
+driven by the `FramePump` below.
+
+### Live audio capture (TASK 4 ship step 4 — shipped 2026-08-12, game audio bar follow-up 2026-08-13, plans in TASKS.md)
+
+**Capture runs for the app's lifetime and is KISS by rule**: desktop/game audio is automatic (WASAPI
+loopback), the mic is the creator's only audio control (meter/mute/volume already shipped). The whole
+layer sits behind an **`IAudioSource` seam** (`Services/Audio/`: `Start`/`Stop`/`Started`/`SampleReady`/
+`Failed`, IDisposable) so the app never touches NAudio directly and tests inject hermetic fakes (no
+devices, no timers).
+
+- **Sources (NAudio `NAudio.Wasapi` 2.2.1, MIT — item 9 in `THIRD-PARTY-NOTICES.txt`):**
+  `WasapiLoopbackAudioSource` = `WasapiLoopbackCapture` on the default render device;
+  `WasapiMicAudioSource` = `WasapiCapture` with the device resolved by `FriendlyName` matching
+  `MicSourceName` (the app only persists the **DisplayName**), falling back to the default capture
+  endpoint. Mic device resolution re-reads the name provider `Func<string?>` at each `Start`, so a mic
+  picked mid-session takes effect **immediately** (the mixer restarts the mic on pick). Both sources
+  raise `Started` once their capture loop actually begins — the mixer turns that into `MicConnected`.
+- **`AudioMixer`** owns both sources; **`StartMicCaptureAsync` starts the mixer once at startup** and
+  `Shutdown` disposes it — NOT go-live — so the meters preview live (`BeginGoLive`/`StopStream`
+  no longer touch the mixer). Mic samples feed a pure **`AudioLevelMeter`** (RMS with 0.2 exponential
+  smoothing) → `MicLevelChanged` → marshalled to the UI thread → `AudioLevel`; loopback samples feed a
+  second meter → `LoopbackLevelChanged` → the game bar's `GameAudioLevel`. The raw linear level is
+  mapped to the meter's display scale by `AudioLevelMeter.ToDisplay` (−60..0 dBFS → 0..1): real speech/
+  game RMS is ~0.01..0.1 linear, which would leave a flat scale looking dead. **Mic connection state
+  surfaces as events:** `MicConnected` (source `Started`), `MicFailed` (source `Failed`), and
+  `RestartMic()` re-resolves + restarts just the mic (loopback keeps running). Failures log via
+  `AppLog`; a mic failure zeroes the meter, a loopback failure never kills the mic. Meter `Push` is
+  unconditional (a `?.` on the event would skip the argument — and the meter update — when nothing is
+  subscribed yet).
+- **Mic status dot (`Models/MicStatus.cs`)** on the footer's MIC button: green = `MicConnected`,
+  yellow = `MicFailed` (in use/unplugged), red = no mic device at startup (the mixer is never started,
+  so loopback and the game bar can't run either — no capture devices at all).
+- **Game audio bar** (desktop/game, only while a full-screen game is up in the preview):
+  `IGameAudioDetector` seam (`Services/IGameAudioDetector.cs`), pure `GameAudioHysteresis` (SHOW after
+  ~500ms of fullscreen + sound, HIDE after ~1s away from fullscreen, **silence never hides an active
+  bar**), and the default `GameAudioDetector` composing `IFullScreenDetector` + the live loopback level
+  (floor 0.5%). WPF-free — the VM owns a 250ms `DispatcherTimer` that polls it and flips
+  `IsGameAudioBarVisible`. The bar is **overlaid at the bottom of the preview window** (bottom-center,
+  dark translucent chip, a mirror of the mic bar: meter + mute + volume slider). It's monitoring UI
+  only — it lives in the XAML preview (`MainWindow.xaml`, the PreviewGrid) and never reaches the live
+  output (the `SceneCompositor` doesn't know about it).
+- **`WaveToFloat`** (pure, shared): WASAPI mix formats → interleaved float — IEEE float 32-bit direct,
+  PCM 16-bit normalized to -1..1, `WaveFormatExtensible` with the IEEE-float subformat GUID
+  (`NAudio.Dmo.AudioMediaSubtypes.MEDIASUBTYPE_IEEE_FLOAT`), trailing partial samples ignored.
+- Build **0 warnings**; **169 passing** (mixer/hysteresis/game-detector/meter-scale unit tests).
+
+**Deferred:** the loopback→encoder AAC mix wiring (a later step — the encoder construction + frame
+pipeline shipped in ship step 5).
+
+### Live frame pipeline (TASK 4 ship step 5 — shipped 2026-08-12, health stats 2026-08-13, plan in TASKS.md)
+
+The **`FramePump`** (`Services/Encoder/`) is the live frame producer: while live it snapshots the active
+scene each tick, resolves every element to its latest frame, composites it into the tier's output frame,
+and paces frames into the encoder at the tier's FPS. **Pattern — everything is a constructor-injected
+seam:** `Func<Scene?>`, `Func<SceneElement, VideoFrame?>` resolver, `Func<CompositorOptions>`,
+`Func<EncoderOptions?>`, `Func<IFfmpegEncoder>`, `Action<string>` log, and an injectable pacing delay
+(default `Task.Delay`; tests inject `Task.Yield`). The pump is free of WPF and of the capture managers.
+
+- **`StartAsync` never throws** — the VM fires-and-forgets it from the sync command handler; failures log
+  + surface via the `Failed` event. `EncoderOptions == null` means "no RTMP URL": the pump logs and skips
+  the encoder entirely. `MainViewModel._rtmpUrlProvider` is that seam — a `Func<string?>` returning null
+  until TASK 5 supplies the reusable stream's ingest URL, so go-live runs the current visual flow.
+- **Stop ordering matters:** `StopAsync` stops the encoder (closes stdin → EOF → ffmpeg finalizes+exits)
+  **before** awaiting the loop, because closing stdin unblocks a write stuck on pipe backpressure — the
+  reverse order would deadlock. `ProcessFailed` self-stops the pump. `Failed` while live flips
+  `StreamStatus.Error` (minimal).
+- **Health stats (ship step 6, shipped 2026-08-13):** `HealthUpdated` is bound to the bottom bar —
+  `MainViewModel.OnFramePumpHealthUpdated` marshals to the UI thread (the encoder's stderr loop raises on
+  a background thread) and copies into `CurrentHealth` (the bottom bar's existing `CurrentHealth.*`
+  bindings). `ResetHealth(status)` 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 (`ApplyStreamQuality`). The bar shows
+  real encoder values once TASK 5 fills `_rtmpUrlProvider`; until then the pump skips the encoder.
+- **`MainViewModel` owns the resolver** (`ResolveOutputFrame`): `WebcamSceneConfig` →
+  `CameraManager.GetLatestFrame(WebcamId)`, `Source { IsLiveCapture, CaptureKey }` →
+  `ScreenCaptureManager.GetLatestFrame(CaptureKey)` (the new accessor mirroring `CameraManager`), image/
+  background → `StaticPixelCache.Get(AssetId)`. `BuildCompositorOptions` rounds the VM's `OutputRect*`
+  doubles to ints — the vertical 607.5 half-pixel crop rounds to a perfectly-centered **608** (`Math.Round`,
+  ToEven); `BuildEncoderOptions` fills W×H/FPS/bitrate from the tier once the URL provider yields one.
+- **Social bar on the output (bar bug-fix branch):** the `FramePump` takes an optional
+  `socialBar: Func<(VideoFrame? Frame, SocialBarPosition Position)>?` seam, re-read **every frame** (so a
+  mid-stream position flip applies immediately). The strip is pre-rasterized by `Compositor/SocialBarRenderer.cs`
+  (WPF glue — WPF glue here is fine because the strip is rendered once per config change on the UI thread,
+  the resulting immutable frame is then composited pure-CPU by `SceneCompositor`), and `SceneCompositor.Render`
+  blits it **last — above the branding flash** at `socialBarTop` (0 = top, `SourceRectHeight − barHeight` =
+  bottom) in master space. `MainViewModel` owns the frame (`_socialBarFrame`, rebuilt by `RenderSocialBarFrame`
+  on load/save/`NotifySocialsChanged`).
+- 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` + the pump stops) rather than
+  crashing. The background thread + video pipeline is the new reality since this step.
+
+### Social bar (TASK 14 — shipped 2026-08-12, plan in TASKS.md; bar bug-fix branch 2026-08-13)
 
 A **global bar layer** (never a Source, no sources-list row) that sits over the bottom or top of the
-output and carries the creator's social links — content-sized, centered, GREEN glow when ON, top/bottom
-snap-drag (default BOTTOM, persisted `SocialBarPosition`). `Models/Socials.cs`: `SocialService` enum
+output and carries the creator's social links — content-sized, centered, GREEN glow when ON, position is a
+**click-toggle top ⇄ bottom** (default BOTTOM, persisted `SocialBarPosition`). `Models/Socials.cs`: `SocialService` enum
 (YouTube/Twitch/X/Instagram/TikTok/Facebook/Discord/Kick/Threads/Bluesky/GitHub/LinkedIn/Pinterest/
 Snapchat/Reddit/WhatsApp/Telegram/Link/Website/**Fediverse**), `SocialEntry` (Service/Handle/ProfileUrl/
 `FediverseSoftware`), `SocialsConfig` (Entries + `BarPosition` + `BarEnabled`; `BarJustify` dropped,
@@ -356,6 +477,26 @@ honeycomb fallback — Simple Icons CC0 path data, initials badges gone); nodein
 `CancellationToken` (dialog VM owns a CTS; Cancel/X/Save abort in-flight lookups, canceled continuations
 never touch slot state).
 
+**Bar bug-fix branch (2026-08-13) — three changes:**
+
+1. **Positioning is a click-toggle (KISS)** — the original drag set a local `Canvas.SetTop` value that
+   permanently overrides the `{Binding SocialBarTop}` (a binding can never win over a local value), so the
+   bar stayed wherever it was dropped. The first drag-snap fix (`SocialBarSnap.Decide` + `ClearValue` on
+   release) still failed for shaky hands — jitter around the ±6px deadzone snapped the bar up but wouldn't
+   let it come back down. **Superseded by the user's click-toggle:** clicking the bar flips it top ⇄ bottom
+   (`MainViewModel.ToggleSocialBarPosition`), the bar rides the binding alone, and `SocialBarSnap` is gone.
+2. **Fediverse software self-heal** — the DB row `@gramps@llamachile.tube` had `Software = NULL` because
+   nodeinfo was only ever asked of the identity domain (a landing page; the real instance is
+   `mastodon.llamachile.tube`). `HttpSocialValidator.ResolveFediverseSoftwareAsync` 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. `MainViewModel` runs the
+   static `HealFediverseSoftwareAsync` off the UI thread on layout load, applies matches via the dispatcher,
+   and saves; `SocialEntry.FediverseSoftware` is settable and raises `LogoData`, so the icon updates in place.
+3. **The bar renders on the live output** — `Compositor/SocialBarRenderer.cs` rasterizes the entries into a
+   transparent straight-alpha BGRA strip (1920-wide, 40px content + 24px glow pad, the green glow baked in,
+   Pbgra32→straight-alpha unpremultiply) and the compositor blits it above the flash (see "Live frame
+   pipeline").
+
 ### Licensing — do not violate (GA = paid product; see `THIRD-PARTY-NOTICES.txt`)
 
 This product is closed-source and paid. Every third-party component must stay inside the LGPL/BSD/MIT

ytLive.Tests/AudioMixerTests.cs

@@ -0,0 +1,394 @@
+using NAudio.Wave;
+using Xunit;
+using ytLive.Services.Audio;
+
+namespace ytLive.Tests;
+
+/// <summary>
+/// TASK 4 ship step 4: WASAPI audio capture behind the <see cref="IAudioSource"/>
+/// seam. The units pin down the pure pieces — byte→float conversion, the level
+/// meter math, and the mixer lifecycle/forwarding against fakes. No real audio
+/// devices (NAudio device resolution is a thin wrapper left to a manual smoke
+/// test), no timers.
+/// </summary>
+public class AudioMixerTests
+{
+    private sealed class FakeSource : IAudioSource
+    {
+        public int StartCount { get; private set; }
+        public int StopCount { get; private set; }
+        public bool Disposed { get; private set; }
+        public event Action? Started;
+        public event Action<AudioSample>? SampleReady;
+        public event Action<Exception>? Failed;
+
+        public void Start() => StartCount++;
+        public void Stop() => StopCount++;
+        public void Dispose() => Disposed = true;
+
+        public void MarkStarted() => Started?.Invoke();
+        public void Emit(AudioSample sample) => SampleReady?.Invoke(sample);
+        public void Fail(Exception ex) => Failed?.Invoke(ex);
+    }
+
+    [Fact]
+    public void Start_StartsBothSources()
+    {
+        var mic = new FakeSource();
+        var loopback = new FakeSource();
+        var mixer = new AudioMixer(mic, loopback);
+
+        mixer.Start();
+
+        Assert.Equal(1, mic.StartCount);
+        Assert.Equal(1, loopback.StartCount);
+    }
+
+    [Fact]
+    public void Start_IsIdempotent()
+    {
+        var mic = new FakeSource();
+        var mixer = new AudioMixer(mic, new FakeSource());
+
+        mixer.Start();
+        mixer.Start();
+
+        Assert.Equal(1, mic.StartCount);
+    }
+
+    [Fact]
+    public void Stop_StopsBothAndResetsLevel()
+    {
+        var mic = new FakeSource();
+        var loopback = new FakeSource();
+        var mixer = new AudioMixer(mic, loopback);
+        mixer.Start();
+        mic.Emit(new AudioSample(new[] { 0.8f }, 48000, 1));
+
+        var last = -1f;
+        mixer.MicLevelChanged += l => last = l;
+        mixer.Stop();
+
+        Assert.Equal(1, mic.StopCount);
+        Assert.Equal(1, loopback.StopCount);
+        Assert.Equal(0f, last);
+        Assert.Equal(0f, mixer.MicLevel);
+    }
+
+    [Fact]
+    public void Stop_WithNoStart_DoesNothing()
+    {
+        var mic = new FakeSource();
+        var mixer = new AudioMixer(mic, new FakeSource());
+
+        mixer.Stop();
+
+        Assert.Equal(0, mic.StopCount);
+    }
+
+    [Fact]
+    public void MicSamples_DriveMicLevelChanged()
+    {
+        var mic = new FakeSource();
+        var mixer = new AudioMixer(mic, new FakeSource());
+        var levels = new List<float>();
+        mixer.MicLevelChanged += l => levels.Add(l);
+
+        mixer.Start();
+        mic.Emit(new AudioSample(new[] { 1f, 1f, 1f, 1f }, 48000, 1));
+        mic.Emit(new AudioSample(new[] { -1f, -1f, -1f, -1f }, 48000, 1));
+
+        Assert.NotEmpty(levels);
+        Assert.All(levels, l => Assert.InRange(l, 0f, 1f));
+    }
+
+    [Fact]
+    public void LoopbackSamples_DoNotChangeMicLevel()
+    {
+        var loopback = new FakeSource();
+        var mixer = new AudioMixer(new FakeSource(), loopback);
+        var levels = new List<float>();
+        mixer.MicLevelChanged += l => levels.Add(l);
+
+        mixer.Start();
+        loopback.Emit(new AudioSample(new[] { 1f, 1f, 1f, 1f }, 48000, 2));
+
+        Assert.Empty(levels);
+        Assert.Equal(0f, mixer.MicLevel);
+    }
+
+    [Fact]
+    public void MicSamples_DoNotChangeLoopbackLevel()
+    {
+        var mic = new FakeSource();
+        var mixer = new AudioMixer(mic, new FakeSource());
+        var levels = new List<float>();
+        mixer.LoopbackLevelChanged += l => levels.Add(l);
+
+        mixer.Start();
+        mic.Emit(new AudioSample(new[] { 1f, 1f, 1f, 1f }, 48000, 1));
+
+        Assert.Empty(levels);
+        Assert.Equal(0f, mixer.LoopbackLevel);
+    }
+
+    [Fact]
+    public void LoopbackSamples_DriveLoopbackLevelChanged()
+    {
+        var loopback = new FakeSource();
+        var mixer = new AudioMixer(new FakeSource(), loopback);
+        var levels = new List<float>();
+        mixer.LoopbackLevelChanged += l => levels.Add(l);
+
+        mixer.Start();
+        loopback.Emit(new AudioSample(new[] { 1f, 1f, 1f, 1f }, 48000, 2));
+        loopback.Emit(new AudioSample(new[] { -1f, -1f, -1f, -1f }, 48000, 2));
+
+        Assert.NotEmpty(levels);
+        Assert.All(levels, l => Assert.InRange(l, 0f, 1f));
+    }
+
+    [Fact]
+    public void MicStarted_RaisesMicConnected()
+    {
+        var mic = new FakeSource();
+        var mixer = new AudioMixer(mic, new FakeSource());
+        var connected = 0;
+        mixer.MicConnected += () => connected++;
+
+        mixer.Start();
+        mic.MarkStarted();
+
+        Assert.Equal(1, connected);
+    }
+
+    [Fact]
+    public void MicFailure_RaisesMicFailed()
+    {
+        var mic = new FakeSource();
+        var mixer = new AudioMixer(mic, new FakeSource());
+        Exception? failed = null;
+        mixer.MicFailed += ex => failed = ex;
+
+        mixer.Start();
+        mic.Fail(new InvalidOperationException("boom"));
+
+        Assert.NotNull(failed);
+        Assert.Equal("boom", failed!.Message);
+    }
+
+    [Fact]
+    public void RestartMic_StopsAndRestartsMic_KeepsLoopbackRunning()
+    {
+        var mic = new FakeSource();
+        var loopback = new FakeSource();
+        var mixer = new AudioMixer(mic, loopback);
+        mixer.Start();
+
+        mixer.RestartMic();
+
+        Assert.Equal(2, mic.StartCount);
+        Assert.Equal(1, mic.StopCount);
+        Assert.Equal(1, loopback.StartCount);
+        Assert.Equal(0, loopback.StopCount);
+    }
+
+    [Fact]
+    public void RestartMic_ResetsLevel()
+    {
+        var mic = new FakeSource();
+        var mixer = new AudioMixer(mic, new FakeSource());
+        mixer.Start();
+        mic.Emit(new AudioSample(new[] { 1f, 1f, 1f, 1f }, 48000, 1));
+        Assert.True(mixer.MicLevel > 0);
+
+        float? reset = null;
+        mixer.MicLevelChanged += l => reset = l;
+        mixer.RestartMic();
+
+        Assert.Equal(0f, reset);
+    }
+
+    [Fact]
+    public void MicFailure_LogsAndResetsLevel()
+    {
+        var mic = new FakeSource();
+        var logs = new List<string>();
+        var mixer = new AudioMixer(mic, new FakeSource(), m => logs.Add(m));
+        mixer.Start();
+        mic.Emit(new AudioSample(new[] { 0.5f }, 48000, 1));
+
+        var last = -1f;
+        mixer.MicLevelChanged += l => last = l;
+        mic.Fail(new InvalidOperationException("boom"));
+
+        Assert.Contains(logs, l => l.Contains("boom"));
+        Assert.Equal(0f, last);
+    }
+
+    [Fact]
+    public void LoopbackFailure_LogsButKeepsMic()
+    {
+        var loopback = new FakeSource();
+        var logs = new List<string>();
+        var mixer = new AudioMixer(new FakeSource(), loopback, m => logs.Add(m));
+        mixer.Start();
+
+        var last = -1f;
+        mixer.MicLevelChanged += l => last = l;
+        loopback.Fail(new InvalidOperationException("boom"));
+
+        Assert.Contains(logs, l => l.Contains("boom"));
+        Assert.Equal(-1f, last);
+    }
+
+    [Fact]
+    public void Dispose_StopsAndDisposesSources()
+    {
+        var mic = new FakeSource();
+        var loopback = new FakeSource();
+        var mixer = new AudioMixer(mic, loopback);
+        mixer.Start();
+
+        mixer.Dispose();
+
+        Assert.True(mic.Disposed);
+        Assert.True(loopback.Disposed);
+        Assert.Equal(1, mic.StopCount);
+    }
+
+    [Fact]
+    public void Dispose_UnsubscribesEvents()
+    {
+        var mic = new FakeSource();
+        var loopback = new FakeSource();
+        var mixer = new AudioMixer(mic, loopback);
+        mixer.Dispose();
+
+        var levels = new List<float>();
+        mixer.MicLevelChanged += l => levels.Add(l);
+        mic.Emit(new AudioSample(new[] { 1f }, 48000, 1));
+
+        Assert.Empty(levels);
+    }
+}
+
+public class AudioLevelMeterTests
+{
+    [Fact]
+    public void ConstantSine_ConvergesToRms()
+    {
+        var meter = new AudioLevelMeter();
+        var sample = new AudioSample(new[] { 0.5f, -0.5f, 0.5f, -0.5f }, 48000, 1);
+
+        float level = 0;
+        for (var i = 0; i < 30; i++)
+            level = meter.Push(sample);
+
+        Assert.InRange(level, 0.45f, 0.55f);
+    }
+
+    [Fact]
+    public void Silence_DrivesTowardZero()
+    {
+        var meter = new AudioLevelMeter();
+        meter.Push(new AudioSample(new[] { 1f, 1f, 1f, 1f }, 48000, 1));
+        var samples = new float[1024];
+        var sample = new AudioSample(samples, 48000, 1);
+
+        for (var i = 0; i < 50; i++)
+            meter.Push(sample);
+
+        Assert.Equal(0f, meter.Level, 3);
+    }
+
+    [Fact]
+    public void EmptySample_KeepsLevel()
+    {
+        var meter = new AudioLevelMeter();
+        meter.Push(new AudioSample(new[] { 1f, 1f, 1f, 1f }, 48000, 1));
+        var before = meter.Level;
+
+        var level = meter.Push(new AudioSample(Array.Empty<float>(), 48000, 1));
+
+        Assert.Equal(before, level);
+    }
+
+    [Fact]
+    public void Reset_ZerosLevel()
+    {
+        var meter = new AudioLevelMeter();
+        meter.Push(new AudioSample(new[] { 1f, 1f, 1f, 1f }, 48000, 1));
+
+        meter.Reset();
+
+        Assert.Equal(0f, meter.Level);
+    }
+
+    [Fact]
+    public void ToDisplay_IsLogarithmic()
+    {
+        Assert.Equal(0f, AudioLevelMeter.ToDisplay(0f));
+        Assert.Equal(0f, AudioLevelMeter.ToDisplay(0.001f), 2);
+
+        // -60 dBFS floor → 0, 0 dBFS → 1, and a decade (~-20 dB) is 1/3 up the bar.
+        Assert.Equal(1f, AudioLevelMeter.ToDisplay(1f), 3);
+        Assert.Equal(0.5f, AudioLevelMeter.ToDisplay(0.0316f), 2);
+        Assert.InRange(AudioLevelMeter.ToDisplay(0.1f), 0.66f, 0.67f);
+        Assert.InRange(AudioLevelMeter.ToDisplay(0.01f), 0.32f, 0.34f);
+    }
+
+    [Fact]
+    public void ToDisplay_ClampsAtFloor()
+    {
+        Assert.Equal(0f, AudioLevelMeter.ToDisplay(0.0001f));
+        Assert.Equal(0f, AudioLevelMeter.ToDisplay(-1f));
+    }
+}
+
+public class WaveToFloatTests
+{
+    private static byte[] FloatSamples(params float[] values)
+    {
+        var bytes = new byte[values.Length * 4];
+        Buffer.BlockCopy(values, 0, bytes, 0, bytes.Length);
+        return bytes;
+    }
+
+    [Fact]
+    public void IeeeFloat32_PreservesValues()
+    {
+        var format = WaveFormat.CreateIeeeFloatWaveFormat(48000, 2);
+        var samples = WaveToFloat.Convert(FloatSamples(0.25f, -0.5f, 1f), 12, format);
+
+        Assert.Equal(3, samples.Length);
+        Assert.Equal(0.25f, samples[0], 4);
+        Assert.Equal(-0.5f, samples[1], 4);
+        Assert.Equal(1f, samples[2], 4);
+    }
+
+    [Fact]
+    public void Pcm16_NormalizesToUnitRange()
+    {
+        var format = WaveFormat.CreateCustomFormat(WaveFormatEncoding.Pcm, 48000, 1, 48000 * 2, 2, 16);
+        var bytes = new byte[] { 0x00, 0x00, 0xFF, 0x7F, 0x00, 0x80 };
+        var samples = WaveToFloat.Convert(bytes, 6, format);
+
+        Assert.Equal(3, samples.Length);
+        Assert.Equal(0f, samples[0], 4);
+        Assert.Equal(1f, samples[1], 4);
+        Assert.Equal(-1f, samples[2], 4);
+    }
+
+    [Fact]
+    public void TruncatedTrailingBytes_AreIgnored()
+    {
+        var format = WaveFormat.CreateIeeeFloatWaveFormat(48000, 2);
+        var bytes = new byte[] { 0, 0, 0x80, 0x3F, 1, 2, 3 }; // 1 float + 3 stray bytes
+
+        var samples = WaveToFloat.Convert(bytes, bytes.Length, format);
+
+        Assert.Single(samples);
+        Assert.Equal(1f, samples[0], 4);
+    }
+}

ytLive.Tests/FfmpegEncoderTests.cs

@@ -0,0 +1,290 @@
+using System.Diagnostics;
+using System.Threading.Channels;
+using Xunit;
+using ytLive.Models;
+using ytLive.Services;
+using ytLive.Services.Encoder;
+
+namespace ytLive.Tests;
+
+/// <summary>
+/// The FFmpeg subprocess encoder (TASK 4 ship step 3). The integration test drives
+/// the full lifecycle against fakes: encoder probe → subprocess start with the right
+/// args → raw frames into stdin → stderr progress parsed into health → graceful stop.
+/// The units pin down the pure pieces (args, progress parser, encoder picker) and
+/// the failure edges. No real ffmpeg binary, no network.
+/// </summary>
+public class FfmpegEncoderTests
+{
+    private sealed class QueuedReader : TextReader
+    {
+        private readonly Channel<string?> _channel = Channel.CreateUnbounded<string?>();
+        public void Enqueue(string s) => _channel.Writer.TryWrite(s);
+        public void Complete() => _channel.Writer.TryComplete();
+        public override string? ReadLine() => ReadLineAsync().GetAwaiter().GetResult();
+
+        public override async Task<string?> ReadLineAsync()
+        {
+            try
+            {
+                return await _channel.Reader.ReadAsync().AsTask().ConfigureAwait(false);
+            }
+            catch (ChannelClosedException)
+            {
+                return null; // stream EOF — the process exited and the pipe closed
+            }
+        }
+    }
+
+    private sealed class FakeEncoderProcess : IEncoderProcess
+    {
+        public ProcessStartInfo? StartInfo { get; private set; }
+        public MemoryStream Stdin { get; } = new();
+        public Stream StandardInput => Stdin;
+        public TextReader StandardOutput { get; }
+        public bool HasExited { get; private set; }
+        public int ExitCode { get; private set; }
+        public bool Killed { get; private set; }
+        public bool Started { get; private set; }
+
+        private readonly TaskCompletionSource _exit =
+            new(TaskCreationOptions.RunContinuationsAsynchronously);
+        private readonly QueuedReader _error = new();
+
+        public FakeEncoderProcess(string probeOutput = "")
+            => StandardOutput = new StringReader(probeOutput);
+
+        public TextReader StandardError => _error;
+        public void EnqueueStderr(string line) => _error.Enqueue(line);
+
+        public void Start(ProcessStartInfo startInfo)
+        {
+            StartInfo = startInfo;
+            Started = true;
+        }
+
+        public void SignalExit(int code = 0)
+        {
+            ExitCode = code;
+            HasExited = true;
+            _error.Complete();
+            _exit.TrySetResult();
+        }
+
+        public void Kill()
+        {
+            Killed = true;
+            _error.Complete();
+            _exit.TrySetResult();
+        }
+
+        public Task WaitForExitAsync(CancellationToken cancellationToken = default) => _exit.Task;
+
+        public void Dispose()
+        {
+            _error.Complete();
+            _exit.TrySetResult();
+        }
+    }
+
+    private sealed class FakeEncoderProcessFactory
+    {
+        private readonly Queue<FakeEncoderProcess> _processes = new();
+        public void Return(FakeEncoderProcess p) => _processes.Enqueue(p);
+        public FakeEncoderProcess Create() => _processes.Dequeue();
+    }
+
+    private sealed class StubLocator : IFfmpegLocator
+    {
+        public Task<string> LocateAsync(CancellationToken cancellationToken = default)
+            => Task.FromResult(@"C:\tools\ffmpeg.exe");
+    }
+
+    private static byte[] BgraFrame(int w, int h, byte b, byte g, byte r)
+    {
+        var bytes = new byte[w * h * 4];
+        for (var i = 0; i < bytes.Length; i += 4)
+        {
+            bytes[i] = b;
+            bytes[i + 1] = g;
+            bytes[i + 2] = r;
+            bytes[i + 3] = 255;
+        }
+        return bytes;
+    }
+
+    [Fact]
+    public async Task Start_ProbesEncoder_FeedsFrames_ParsesHealth_StopsGracefully()
+    {
+        const string encoders =
+            " V..... h264_nvenc  NVIDIA NVENC H.264 encoder (codec h264)\n" +
+            " V..... libopenh264  OpenH264 H.264 (codec h264)\n";
+        var probe = new FakeEncoderProcess(encoders);
+        var encoderProc = new FakeEncoderProcess();
+        var factory = new FakeEncoderProcessFactory();
+        factory.Return(probe);
+        factory.Return(encoderProc);
+
+        using var encoder = new FfmpegEncoder(new StubLocator(), factory.Create);
+
+        var health = new TaskCompletionSource<StreamHealth>(TaskCreationOptions.RunContinuationsAsynchronously);
+        encoder.HealthUpdated += (_, h) => health.TrySetResult(h);
+
+        var options = new EncoderOptions
+        {
+            RtmpUrl = "rtmp://a.rtmp.youtube.com/live2/abc-xyz",
+            Width = 1920,
+            Height = 1080,
+            Fps = 60,
+            BitrateKbps = 8000,
+        };
+
+        await encoder.StartAsync(options);
+
+        Assert.True(probe.Started, "the -encoders probe must run");
+        Assert.True(encoderProc.Started, "the encoder subprocess must start");
+        Assert.Equal(@"C:\tools\ffmpeg.exe", encoderProc.StartInfo!.FileName);
+        var args = encoderProc.StartInfo.ArgumentList.ToArray();
+        var c = Array.IndexOf(args, "-c:v");
+        Assert.True(
+            args[c + 1] == "h264_nvenc",
+            "hardware NVENC must be preferred over the listed openh264");
+
+        await encoder.SubmitFrameAsync(new VideoFrame(1920, 1080, BgraFrame(1920, 1080, 255, 0, 0)));
+        await encoder.SubmitFrameAsync(new VideoFrame(1920, 1080, BgraFrame(1920, 1080, 0, 255, 0)));
+        Assert.Equal(2 * 1920 * 1080 * 4, encoderProc.Stdin.Length);
+
+        encoderProc.EnqueueStderr(
+            "frame= 120 fps= 59.9 q=28.0 size= 1024KiB time=00:00:02.00 bitrate= 4000.1kbits/s speed=1.00x");
+        var h = await health.Task.WaitAsync(TimeSpan.FromSeconds(5));
+        Assert.Equal(4000.1, h.CurrentBitrate, 1);
+        Assert.Equal(59.9, h.FPS, 1);
+        Assert.Equal(TimeSpan.FromSeconds(2), h.StreamDuration);
+
+        encoderProc.SignalExit();
+        await encoder.StopAsync();
+        Assert.False(encoder.IsRunning);
+        Assert.False(encoderProc.Killed, "graceful stop must not kill the process");
+        Assert.Equal(StreamStatus.Offline, h.Status);
+    }
+
+    [Fact]
+    public async Task Start_WithoutRtmpUrl_Throws()
+    {
+        using var encoder = new FfmpegEncoder(new StubLocator());
+        await Assert.ThrowsAsync<ArgumentException>(() => encoder.StartAsync(new EncoderOptions()));
+    }
+
+    [Fact]
+    public async Task SubmitFrame_WhenNotRunning_Throws()
+    {
+        using var encoder = new FfmpegEncoder(new StubLocator());
+        await Assert.ThrowsAsync<InvalidOperationException>(
+            () => encoder.SubmitFrameAsync(new VideoFrame(2, 2, new byte[16])));
+    }
+
+    [Fact]
+    public async Task Stop_WithoutStart_IsNoop()
+    {
+        using var encoder = new FfmpegEncoder(new StubLocator());
+        await encoder.StopAsync();
+        Assert.False(encoder.IsRunning);
+    }
+
+    [Fact]
+    public async Task ProcessDeath_RaisesFailed()
+    {
+        var encoderProc = new FakeEncoderProcess();
+        var factory = new FakeEncoderProcessFactory();
+        factory.Return(new FakeEncoderProcess());
+        factory.Return(encoderProc);
+
+        using var encoder = new FfmpegEncoder(new StubLocator(), factory.Create);
+        var failed = new TaskCompletionSource<string>(TaskCreationOptions.RunContinuationsAsynchronously);
+        encoder.ProcessFailed += (_, msg) => failed.TrySetResult(msg);
+
+        await encoder.StartAsync(new EncoderOptions { RtmpUrl = "rtmp://x/y" });
+        encoderProc.SignalExit(1);
+        var msg = await failed.Task.WaitAsync(TimeSpan.FromSeconds(5));
+        Assert.Contains("1", msg);
+    }
+
+    [Fact]
+    public void Args_Gop_IsFpsTimesFour()
+    {
+        var options = new EncoderOptions { Fps = 60 };
+        Assert.Equal(240, options.GopSize);
+
+        var args = FfmpegArgs.Build(options, "libopenh264").ToArray();
+        var g = Array.IndexOf(args, "-g");
+        Assert.Equal("240", args[g + 1]);
+        var keyint = Array.IndexOf(args, "-keyint_min");
+        Assert.Equal("240", args[keyint + 1]);
+    }
+
+    [Fact]
+    public void Args_IncludeInputOutputAndCompliance()
+    {
+        var args = FfmpegArgs.Build(
+            new EncoderOptions
+            {
+                RtmpUrl = "rtmp://a.rtmp.youtube.com/live2/key",
+                Width = 1920,
+                Height = 1080,
+                Fps = 60,
+                BitrateKbps = 8000,
+            },
+            "libopenh264").ToArray();
+
+        Assert.Contains("-f", args);
+        Assert.Contains("rawvideo", args);
+        Assert.Contains("pipe:0", args);
+        Assert.Contains("1920x1080", args);
+        Assert.Contains("anullsrc=channel_layout=stereo:sample_rate=48000", args);
+        Assert.Contains("-sc_threshold", args);
+        Assert.Contains("-bf", args);
+        Assert.Contains("yuv420p", args);
+        Assert.Contains("aac", args);
+        Assert.Contains("flv", args);
+        Assert.Contains("rtmp://a.rtmp.youtube.com/live2/key", args);
+    }
+
+    [Fact]
+    public void ProgressParser_ParsesRealStatsLine()
+    {
+        var p = FfmpegProgressParser.TryParse(
+            "frame=  123 fps= 59.9 q=28.0 size=   1024KiB time=00:00:02.04 bitrate= 4000.1kbits/s speed=1.00x");
+        Assert.NotNull(p);
+        Assert.Equal(123, p.Value.Frame);
+        Assert.Equal(59.9, p.Value.Fps, 1);
+        Assert.Equal(4000.1, p.Value.BitrateKbps, 1);
+        Assert.Equal(2.04, p.Value.Duration.TotalSeconds, 2);
+        Assert.Equal(1024 * 1024, p.Value.SizeBytes);
+    }
+
+    [Fact]
+    public void ProgressParser_IgnoresBannerAndErrors()
+    {
+        Assert.Null(FfmpegProgressParser.TryParse("ffmpeg version 6.1 Copyright (c) 2000-2026 the FFmpeg developers"));
+        Assert.Null(FfmpegProgressParser.TryParse("Error while opening encoder for output stream #0:0"));
+        Assert.Null(FfmpegProgressParser.TryParse(""));
+    }
+
+    [Fact]
+    public void EncoderPicker_PrefersHardware_NeverLibx264()
+    {
+        var listing =
+            " V..... libx264   libx264 H.264 / AVC (codec h264)\n" +
+            " V..... libopenh264  OpenH264 H.264 (codec h264)\n" +
+            " V..... h264_nvenc  NVIDIA NVENC H.264 encoder (codec h264)\n";
+        Assert.Equal("h264_nvenc", FfmpegEncoderPicker.Pick(listing));
+
+        var onlyGpl = " V..... libx264   libx264 H.264 / AVC (codec h264)\n";
+        Assert.Equal("libopenh264", FfmpegEncoderPicker.Pick(onlyGpl));
+
+        var software = " V..... libopenh264  OpenH264 H.264 (codec h264)\n";
+        Assert.Equal("libopenh264", FfmpegEncoderPicker.Pick(software));
+
+        Assert.Equal("libopenh264", FfmpegEncoderPicker.Pick("no encoders at all"));
+    }
+}

ytLive.Tests/FramePumpTests.cs

@@ -0,0 +1,266 @@
+using Xunit;
+using ytLive.Models;
+using ytLive.Services;
+using ytLive.Services.Compositor;
+using ytLive.Services.Encoder;
+
+namespace ytLive.Tests;
+
+/// <summary>
+/// The live frame producer (TASK 4 ship step 5): composites the active scene at
+/// the tier's FPS and paces frames into the encoder. The integration test drives
+/// the full lifecycle against fakes — real SceneCompositor + real FramePump, fake
+/// IFfmpegEncoder — proving the composite frame actually reaches the encoder and
+/// that stop tears the pump down cleanly. The units pin the failure edges: the
+/// no-URL skip (the TASK 5 seam), re-entrancy, and encoder death.
+/// </summary>
+public class FramePumpTests
+{
+    private sealed class FakeEncoder : IFfmpegEncoder
+    {
+        public readonly List<VideoFrame> Frames = new();
+        public int StartCount;
+        public int StopCount;
+        public bool Disposed;
+        public EncoderOptions? LastOptions;
+        public Exception? StartError;
+        public TaskCompletionSource FrameArrived = new(TaskCreationOptions.RunContinuationsAsynchronously);
+
+        public event EventHandler<StreamHealth>? HealthUpdated;
+        public event EventHandler<string>? ProcessFailed;
+
+        public Task StartAsync(EncoderOptions options, CancellationToken cancellationToken = default)
+        {
+            StartCount++;
+            LastOptions = options;
+            if (StartError != null) throw StartError;
+            return Task.CompletedTask;
+        }
+
+        public Task SubmitFrameAsync(VideoFrame frame, CancellationToken cancellationToken = default)
+        {
+            Frames.Add(frame);
+            FrameArrived.TrySetResult();
+            return Task.CompletedTask;
+        }
+
+        public Task StopAsync(CancellationToken cancellationToken = default)
+        {
+            StopCount++;
+            return Task.CompletedTask;
+        }
+
+        public void Dispose() => Disposed = true;
+
+        public void RaiseProcessFailed(string message) => ProcessFailed?.Invoke(this, message);
+
+        public void RaiseHealth(StreamHealth health) => HealthUpdated?.Invoke(this, health);
+    }
+
+    private static Scene BackdropScene()
+    {
+        var scene = new Scene { Name = "Live" };
+        scene.Elements.Add(new Source { Type = SourceType.DisplayCapture, IsBackdrop = true, CaptureKey = "monitor:0" });
+        return scene;
+    }
+
+    private static FramePump NewPump(FakeEncoder encoder, Func<EncoderOptions?>? options = null,
+        Func<Scene?>? scene = null, Func<SceneElement, VideoFrame?>? resolve = null,
+        List<string>? log = null,
+        Func<(VideoFrame? Frame, SocialBarPosition Position)>? socialBar = null)
+    {
+        return new FramePump(
+            sceneProvider: scene ?? (() => BackdropScene()),
+            frameResolver: resolve ?? (_ => null),
+            compositorOptions: () => new CompositorOptions
+            {
+                SourceRectX = 0, SourceRectY = 0, SourceRectWidth = 64, SourceRectHeight = 48,
+                OutputWidth = 64, OutputHeight = 48,
+            },
+            encoderOptions: options ?? (() => new EncoderOptions
+            {
+                RtmpUrl = "rtmp://a.rtmp.youtube.com/live2/abc",
+                Width = 64, Height = 48, Fps = 60,
+            }),
+            encoderFactory: () => encoder,
+            log: log != null ? m => log.Add(m) : null,
+            pacingDelay: async (_, _) => await Task.Yield(), // deterministic: no real waits
+            socialBar: socialBar);
+    }
+
+    private static void AssertColor(VideoFrame frame, int x, int y, byte r, byte g, byte b)
+    {
+        var i = (y * frame.Width + x) * 4;
+        var br = frame.BgraPixels[i + 2];
+        var bg = frame.BgraPixels[i + 1];
+        var bb = frame.BgraPixels[i];
+        Assert.True(
+            Math.Abs(br - r) <= 2 && Math.Abs(bg - g) <= 2 && Math.Abs(bb - b) <= 2,
+            $"pixel ({x},{y}): expected rgb({r},{g},{b}), got rgb({br},{bg},{bb})");
+    }
+
+    [Fact]
+    public async Task Start_CompositesScene_FeedsEncoder_StopsCleanly()
+    {
+        var red = SceneCompositorTests.Solid(64, 48, 255, 0, 0);
+        var encoder = new FakeEncoder();
+        using var pump = NewPump(encoder,
+            resolve: e => e is Source { IsBackdrop: true } ? red : null);
+
+        await pump.StartAsync();
+        Assert.True(pump.IsRunning);
+        Assert.Equal(1, encoder.StartCount);
+
+        await encoder.FrameArrived.Task.WaitAsync(TimeSpan.FromSeconds(5));
+        Assert.NotEmpty(encoder.Frames);
+        var frame = encoder.Frames[0];
+        Assert.Equal(64, frame.Width);
+        Assert.Equal(48, frame.Height);
+        AssertColor(frame, 0, 0, 255, 0, 0); // the backdrop really was composited in
+
+        await pump.StopAsync();
+        Assert.False(pump.IsRunning);
+        Assert.Equal(1, encoder.StopCount);
+        Assert.True(encoder.Disposed);
+    }
+
+    [Fact]
+    public async Task Start_WithoutRtmpUrl_SkipsEncoder()
+    {
+        var encoder = new FakeEncoder();
+        var log = new List<string>();
+        using var pump = NewPump(encoder, options: () => null, log: log);
+
+        await pump.StartAsync();
+
+        Assert.False(pump.IsRunning);
+        Assert.Equal(0, encoder.StartCount);
+        Assert.Contains(log, m => m.Contains("RTMP"));
+
+        await pump.StopAsync(); // no-op after a skipped start
+        Assert.Equal(0, encoder.StopCount);
+    }
+
+    [Fact]
+    public async Task Start_WhileRunning_IsNoop()
+    {
+        var encoder = new FakeEncoder();
+        using var pump = NewPump(encoder);
+
+        await pump.StartAsync();
+        await pump.StartAsync();
+
+        Assert.Equal(1, encoder.StartCount);
+    }
+
+    [Fact]
+    public async Task Stop_WithoutStart_IsNoop()
+    {
+        var encoder = new FakeEncoder();
+        using var pump = NewPump(encoder);
+
+        await pump.StopAsync();
+
+        Assert.Equal(0, encoder.StopCount);
+        Assert.False(pump.IsRunning);
+    }
+
+    [Fact]
+    public async Task Start_WithSocialBarSeam_PlacesBarAtTopThenBottomEdge()
+    {
+        var red = SceneCompositorTests.Solid(64, 48, 255, 0, 0);
+        var bar = new VideoFrame(64, 8, new byte[64 * 8 * 4]);
+        Array.Fill(bar.BgraPixels, (byte)255); // opaque white strip
+
+        var encoder = new FakeEncoder();
+        var position = SocialBarPosition.Top;
+        using var pump = NewPump(encoder,
+            resolve: e => e is Source { IsBackdrop: true } ? red : null,
+            socialBar: () => (bar, position));
+
+        await pump.StartAsync();
+        await encoder.FrameArrived.Task.WaitAsync(TimeSpan.FromSeconds(5));
+        Assert.NotEmpty(encoder.Frames);
+        AssertColor(encoder.Frames[0], 0, 0, 255, 255, 255); // bar at the top edge
+
+        // Flip to Bottom: the pump re-reads the seam each frame, so a later frame
+        // lands the bar at the bottom edge (SourceRectHeight - bar height) and the
+        // top corner clears back to backdrop.
+        position = SocialBarPosition.Bottom;
+        VideoFrame? flipped = null;
+        var deadline = DateTime.UtcNow.AddSeconds(5);
+        while (DateTime.UtcNow < deadline && flipped == null)
+        {
+            for (var i = 1; i < encoder.Frames.Count; i++)
+            {
+                var f = encoder.Frames[i];
+                if (f.BgraPixels[2] == 255 && f.BgraPixels[1] == 0 && f.BgraPixels[0] == 0)
+                {
+                    flipped = f;
+                    break;
+                }
+            }
+            if (flipped == null) await Task.Delay(10);
+        }
+        Assert.NotNull(flipped);
+        AssertColor(flipped!, 0, 47, 255, 255, 255); // bar sits on the bottom edge
+
+        await pump.StopAsync();
+    }
+
+    [Fact]
+    public async Task Start_EncoderThrows_RaisesFailed_AndDisposes()
+    {
+        var encoder = new FakeEncoder { StartError = new InvalidOperationException("access denied") };
+        var failed = new TaskCompletionSource<string>(TaskCreationOptions.RunContinuationsAsynchronously);
+        using var pump = NewPump(encoder);
+        pump.Failed += (_, m) => failed.TrySetResult(m);
+
+        await pump.StartAsync();
+
+        Assert.False(pump.IsRunning);
+        var message = await failed.Task.WaitAsync(TimeSpan.FromSeconds(5));
+        Assert.Contains("access denied", message);
+        Assert.True(encoder.Disposed);
+    }
+
+    [Fact]
+    public async Task ProcessDeath_StopsPump_AndRaisesFailed()
+    {
+        var encoder = new FakeEncoder();
+        var failed = new TaskCompletionSource<string>(TaskCreationOptions.RunContinuationsAsynchronously);
+        using var pump = NewPump(encoder);
+        pump.Failed += (_, m) => failed.TrySetResult(m);
+
+        await pump.StartAsync();
+        encoder.RaiseProcessFailed("FFmpeg exited with code 1");
+
+        var message = await failed.Task.WaitAsync(TimeSpan.FromSeconds(5));
+        Assert.Contains("1", message);
+
+        // The pump self-stops (fire-and-forget); poll the definitive teardown
+        // marker — the encoder's disposal — rather than the IsRunning flag, which
+        // StopAsync clears before the loop has fully drained.
+        var deadline = DateTime.UtcNow.AddSeconds(5);
+        while (!encoder.Disposed && DateTime.UtcNow < deadline)
+            await Task.Delay(10);
+        Assert.True(encoder.Disposed);
+        Assert.False(pump.IsRunning);
+    }
+
+    [Fact]
+    public async Task HealthUpdated_ForwardsEncoderHealth()
+    {
+        var encoder = new FakeEncoder();
+        var health = new TaskCompletionSource<StreamHealth>(TaskCreationOptions.RunContinuationsAsynchronously);
+        using var pump = NewPump(encoder);
+        pump.HealthUpdated += (_, h) => health.TrySetResult(h);
+
+        await pump.StartAsync();
+        encoder.RaiseHealth(new StreamHealth { Status = StreamStatus.Streaming, FPS = 59.9 });
+
+        var h = await health.Task.WaitAsync(TimeSpan.FromSeconds(5));
+        Assert.Equal(StreamStatus.Streaming, h.Status);
+        Assert.Equal(59.9, h.FPS, 1);
+    }
+}

ytLive.Tests/GameAudioDetectorTests.cs

@@ -0,0 +1,76 @@
+using Xunit;
+using ytLive.Services;
+
+namespace ytLive.Tests;
+
+/// <summary>
+/// TASK 4 game audio bar: the default detector's provider wiring — it composes
+/// the full-screen monitor + loopback level into the hysteresis and raises
+/// IsGameAudioActiveChanged on transitions. The transition math itself lives in
+/// GameAudioHysteresisTests.
+/// </summary>
+public class GameAudioDetectorTests
+{
+    [Fact]
+    public void Poll_RaisesChanged_WhenGameAppearsAndLeaves()
+    {
+        var now = new DateTime(2026, 8, 13, 12, 0, 0);
+        int? monitor = 0;
+        var level = 0f;
+        var detector = new GameAudioDetector(() => monitor, () => level, () => now);
+        var changes = new List<bool>();
+        detector.IsGameAudioActiveChanged += a => changes.Add(a);
+
+        level = 0.9f;
+        detector.Poll();
+        Assert.False(detector.IsGameAudioActive);
+
+        now = now.AddMilliseconds(600);
+        detector.Poll();
+        Assert.True(detector.IsGameAudioActive);
+        Assert.Equal(new[] { true }, changes);
+
+        level = 0f;
+        now = now.AddSeconds(2);
+        detector.Poll();
+        Assert.True(detector.IsGameAudioActive);
+        Assert.Equal(new[] { true }, changes);
+
+        monitor = null;
+        detector.Poll();
+        Assert.True(detector.IsGameAudioActive);
+
+        now = now.AddSeconds(2);
+        detector.Poll();
+        Assert.False(detector.IsGameAudioActive);
+        Assert.Equal(new[] { true, false }, changes);
+    }
+
+    [Fact]
+    public void Poll_StaysInactive_WhenNoFullScreenMonitor()
+    {
+        var detector = new GameAudioDetector(() => null, () => 0.9f);
+        var changes = 0;
+        detector.IsGameAudioActiveChanged += _ => changes++;
+
+        for (var i = 0; i < 5; i++)
+            detector.Poll();
+
+        Assert.False(detector.IsGameAudioActive);
+        Assert.Equal(0, changes);
+    }
+
+    [Fact]
+    public void Poll_StaysInactive_WhileLoopbackSilent()
+    {
+        var detector = new GameAudioDetector(() => 0, () => 0f);
+        var changes = 0;
+        detector.IsGameAudioActiveChanged += _ => changes++;
+
+        for (var i = 0; i < 5; i++)
+            detector.Poll();
+
+        Assert.False(detector.IsGameAudioActive);
+        Assert.Equal(0, changes);
+    }
+}

ytLive.Tests/GameAudioHysteresisTests.cs

@@ -0,0 +1,82 @@
+using Xunit;
+using ytLive.Services;
+
+namespace ytLive.Tests;
+
+/// <summary>
+/// TASK 4 game audio bar: the pure show/hide state machine. Show = a full-screen
+/// app holds sound for half a second; hide = the app leaves fullscreen for a
+/// second. Silence never hides an active bar — only the game leaving the preview
+/// does (per the creator's rule).
+/// </summary>
+public class GameAudioHysteresisTests
+{
+    private static readonly DateTime T0 = new(2026, 8, 13, 12, 0, 0);
+
+    [Fact]
+    public void StaysInactive_WhileSilent()
+    {
+        var h = new GameAudioHysteresis();
+
+        for (var i = 0; i < 30; i++)
+        {
+            h.Update(true, false, T0.AddSeconds(i));
+            Assert.False(h.IsActive);
+        }
+    }
+
+    [Fact]
+    public void StaysInactive_UntilSoundHoldsHalfSecond()
+    {
+        var h = new GameAudioHysteresis();
+        h.Update(true, true, T0);
+        Assert.False(h.IsActive);
+        h.Update(true, true, T0.AddMilliseconds(400));
+        Assert.False(h.IsActive);
+
+        h.Update(true, true, T0.AddMilliseconds(600));
+        Assert.True(h.IsActive);
+    }
+
+    [Fact]
+    public void NeverHides_WhileGameStillFullScreen_EvenWhenSilent()
+    {
+        var h = new GameAudioHysteresis();
+        h.Update(true, true, T0);
+        h.Update(true, true, T0.AddSeconds(1));
+        Assert.True(h.IsActive);
+
+        for (var i = 2; i < 40; i++)
+        {
+            h.Update(true, false, T0.AddSeconds(i));
+            Assert.True(h.IsActive);
+        }
+    }
+
+    [Fact]
+    public void Hides_AfterAppLeavesFullScreen()
+    {
+        var h = new GameAudioHysteresis();
+        h.Update(true, true, T0);
+        h.Update(true, true, T0.AddSeconds(1));
+        Assert.True(h.IsActive);
+
+        h.Update(false, true, T0.AddSeconds(2));
+        Assert.True(h.IsActive);
+
+        h.Update(false, true, T0.AddSeconds(4));
+        Assert.False(h.IsActive);
+    }
+
+    [Fact]
+    public void StaysInactive_WhenNoFullScreen_EvenWithSound()
+    {
+        var h = new GameAudioHysteresis();
+
+        for (var i = 0; i < 30; i++)
+        {
+            h.Update(false, true, T0.AddSeconds(i));
+            Assert.False(h.IsActive);
+        }
+    }
+}

ytLive.Tests/RealAppCollection.cs

@@ -0,0 +1,83 @@
+using System;
+using System.Threading;
+using System.Windows.Threading;
+using Xunit;
+
+namespace ytLive.Tests;
+
+/// <summary>
+/// Tests that spin up the real WPF App need exactly one Application instance per
+/// AppDomain (WPF enforces it) — so they share this serial collection and a
+/// single App created on one dedicated STA thread. Marshal test bodies onto it
+/// via <see cref="RealAppHost.Run"/>, never `new App()` per test.
+/// </summary>
+[CollectionDefinition("RealApp", DisableParallelization = true)]
+public sealed class RealAppCollection : ICollectionFixture<RealAppHost>
+{
+}
+
+/// <summary>Owns the one-and-only WPF App on a dedicated STA thread.</summary>
+public sealed class RealAppHost : IDisposable
+{
+    private readonly Thread _thread;
+    private readonly Dispatcher _dispatcher;
+
+    public RealAppHost()
+    {
+        Exception? boot = null;
+        Dispatcher? dispatcher = null;
+        _thread = new Thread(() =>
+        {
+            try
+            {
+                var app = new App();
+                app.InitializeComponent();
+                dispatcher = Dispatcher.CurrentDispatcher;
+                Dispatcher.Run();
+            }
+            catch (Exception ex)
+            {
+                boot = ex;
+            }
+        });
+        _thread.SetApartmentState(ApartmentState.STA);
+        _thread.Start();
+        while (dispatcher == null && boot == null)
+            Thread.Sleep(5);
+        if (boot != null)
+            throw new Xunit.Sdk.XunitException("Real WPF App failed to start: " + boot);
+        _dispatcher = dispatcher!;
+    }
+
+    /// <summary>Runs <paramref name="action"/> on the App's STA thread and rethrows any failure.</summary>
+    public void Run(Action action)
+    {
+        Exception? failure = null;
+        _dispatcher.Invoke(() =>
+        {
+            try
+            {
+                action();
+            }
+            catch (Exception ex)
+            {
+                failure = ex;
+            }
+        });
+        if (failure != null)
+            throw failure;
+    }
+
+    public void Dispose()
+    {
+        try
+        {
+            _dispatcher.InvokeShutdown();
+        }
+        catch
+        {
+            // The App never ran its message loop — shutdown is best-effort.
+        }
+        _thread.Join(2000);
+    }
+}

ytLive.Tests/RoundClipInteractionTests.cs

@@ -18,36 +18,24 @@ namespace ytLive.Tests;
 /// (doesn't fall through and deselect the source) and whether the round clip
 /// renders as a circle rather than an oval.
 /// </summary>
+[Collection("RealApp")]
 public sealed class RoundClipInteractionTests
 {
+    private readonly RealAppHost _app;
+
+    public RoundClipInteractionTests(RealAppHost app)
+    {
+        _app = app;
+    }
+
     [Fact]
     public void Round_Clip_Corner_Is_Grabbable_And_Shape_Is_Circle()
     {
-        Exception? failure = null;
-        var thread = new Thread(() =>
-        {
-            try
-            {
-                Run();
-            }
-            catch (Exception ex)
-            {
-                failure = ex;
-            }
-        });
-        thread.SetApartmentState(ApartmentState.STA);
-        thread.Start();
-        thread.Join();
-
-        if (failure != null)
-            throw new Xunit.Sdk.XunitException("Round-clip interaction failed: " + failure);
+        _app.Run(Run);
     }
 
     private void Run()
     {
-        var app = new App();
-        app.InitializeComponent();
-
         // Never let the real MainWindow read/write the user's actual layout DB —
         // Shutdown() saves the layout, which would persist these test sources
         // over the real ones. Point it at a throwaway temp DB instead.

ytLive.Tests/SceneCompositorTests.cs

@@ -180,6 +180,43 @@ public class SceneCompositorTests
         // untouched corner stays pure red
         AssertColor(output, 0, 0, 255, 0, 0);
     }
+
+    [Fact]
+    public void Composite_WithSocialBar_OverlaysAboveFlash_AtTopOrBottom()
+    {
+        var red = Solid(1920, 1080, 255, 0, 0);
+        var backdrop = new Source { Type = SourceType.DisplayCapture, IsBackdrop = true, CaptureKey = "monitor:0" };
+        var scene = new Scene { Name = "Live" };
+        scene.Elements.Add(backdrop);
+
+        var options = new CompositorOptions
+        {
+            SourceRectX = 0, SourceRectY = 0, SourceRectWidth = 1920, SourceRectHeight = 1080,
+            OutputWidth = 1920, OutputHeight = 1080,
+        };
+        var compositor = new SceneCompositor();
+
+        // master-sized overlay: opaque green at (0,0), 50%-white at the center
+        var bar = new VideoFrame(1920, 1080, new byte[1920 * 1080 * 4]);
+        var g = 0;
+        bar.BgraPixels[g] = 0; bar.BgraPixels[g + 1] = 255; bar.BgraPixels[g + 2] = 0; bar.BgraPixels[g + 3] = 255;
+        var w = (540 * 1920 + 960) * 4;
+        bar.BgraPixels[w] = 255; bar.BgraPixels[w + 1] = 255; bar.BgraPixels[w + 2] = 255; bar.BgraPixels[w + 3] = 128;
+
+        // flash: opaque magenta at (0,0) — the bar must cover it
+        var flash = new VideoFrame(1920, 1080, new byte[1920 * 1080 * 4]);
+        flash.BgraPixels[0] = 255; flash.BgraPixels[1] = 0; flash.BgraPixels[2] = 255; flash.BgraPixels[3] = 255;
+
+        var top = compositor.Render(scene, _ => red, flash, options, bar, 0);
+        AssertColor(top, 0, 0, 0, 255, 0); // bar above flash at the top-left
+        AssertColor(top, 960, 540, 255, 127, 127); // 50% white over red
+        AssertColor(top, 100, 100, 255, 0, 0); // empty overlay area: backdrop
+
+        var bottom = compositor.Render(scene, _ => red, flash, options, bar, 1040);
+        AssertColor(bottom, 0, 1040, 0, 255, 0); // bar drawn at the bottom edge
+        AssertColor(bottom, 0, 1039, 255, 0, 0); // backdrop just above the bar
+        AssertColor(bottom, 960, 540, 255, 0, 0); // bar region moved away from center
+    }
 }
 
 public class StretchMathTests

ytLive.Tests/ScreenCaptureManagerTests.cs

@@ -145,6 +145,28 @@ public class ScreenCaptureManagerTests
         Assert.False(await manager.AcquireAsync(" "));
     }
 
+    [Fact]
+    public async Task GetLatestFrame_ReturnsLatestPump_UntilReleased()
+    {
+        FakeScreenSource? captured = null;
+        var manager = new ScreenCaptureManager(key => captured = new FakeScreenSource(key));
+
+        Assert.Null(manager.GetLatestFrame("monitor:0"));
+
+        Assert.True(await manager.AcquireAsync("monitor:0"));
+        Assert.Null(manager.GetLatestFrame("monitor:0")); // nothing pumped yet
+
+        var first = new VideoFrame(2, 2, Pixels(1, 0, 0, 255, 2, 0, 0, 255, 3, 0, 0, 255, 4, 0, 0, 255));
+        var second = new VideoFrame(2, 2, Pixels(5, 0, 0, 255, 6, 0, 0, 255, 7, 0, 0, 255, 8, 0, 0, 255));
+        captured!.Pump(first);
+        captured.Pump(second);
+
+        Assert.Same(second, manager.GetLatestFrame("monitor:0"));
+
+        await manager.ReleaseAsync("monitor:0");
+        Assert.Null(manager.GetLatestFrame("monitor:0"));
+    }
+
     // The one integration test for this branch: one target creates one shared
     // WriteableBitmap, published once, and back-to-back frames coalesce to the
     // latest (a single pending UI copy per session).

ytLive.Tests/SocialBarTests.cs

@@ -1,8 +1,11 @@
 using System.IO;
+using System.Threading;
+using System.Threading.Tasks;
 using Microsoft.Data.Sqlite;
 using Xunit;
 using ytLive.Models;
 using ytLive.Services;
+using ytLive.ViewModels;
 
 namespace ytLive.Tests;
 
@@ -16,6 +19,83 @@ public class SocialBarTests
         return path;
     }
 
+    /// <summary>Resolves every fediverse domain as Mastodon — the heal test only
+    /// cares that a missing stored software name gets filled in and persisted.</summary>
+    private sealed class MastodonValidator : ISocialValidator
+    {
+        public Task<string?> ResolveFediverseSoftwareAsync(string domain, CancellationToken ct)
+            => Task.FromResult<string?>("mastodon");
+
+        public Task<SocialLookupResult> LookupAsync(SocialService service, string handleOrUrl, CancellationToken ct)
+            => throw new System.NotSupportedException();
+    }
+
+    [Fact]
+    public void SocialEntry_FediverseSoftware_SettableUpdatesLogo()
+    {
+        var entry = new SocialEntry
+        {
+            Service = SocialService.Fediverse,
+            Handle = "@gramps@llamachile.tube",
+            ProfileUrl = "https://llamachile.tube/@gramps",
+        };
+        var honeycomb = entry.LogoData;
+        entry.FediverseSoftware = "mastodon";
+        Assert.Equal(SocialServiceIcons.LogoDataForFediverse("mastodon"), entry.LogoData);
+        Assert.NotEqual(honeycomb, entry.LogoData);
+    }
+
+    /// <summary>The single integration test for this branch: a fediverse entry
+    /// persisted with a NULL software name is loaded, healed via the real validator
+    /// seam, and the resolved name is persisted back — surviving a second load.</summary>
+    [Fact]
+    public async Task Socials_HealMissingFediverseSoftware_RoundTripsThroughDb()
+    {
+        var path = TempDbPath();
+        try
+        {
+            var socials = new SocialsConfig();
+            socials.Entries.Add(new SocialEntry
+            {
+                Service = SocialService.Fediverse,
+                Handle = "@gramps@llamachile.tube",
+                ProfileUrl = "https://llamachile.tube/@gramps",
+            });
+            using (var store = new LayoutStore(path))
+                store.Save(new[] { new Scene { Name = "Live" } }, null, socials);
+
+            SocialsConfig? loaded;
+            using (var store = new LayoutStore(path))
+            {
+                store.Load();
+                loaded = store.Socials;
+                Assert.NotNull(loaded);
+                Assert.Null(loaded!.Entries[0].FediverseSoftware);
+            }
+
+            var healed = await MainViewModel.HealFediverseSoftwareAsync(loaded!, new MastodonValidator());
+            Assert.Single(healed);
+            Assert.Equal("mastodon", healed["@gramps@llamachile.tube"]);
+            loaded.Entries[0].FediverseSoftware = healed["@gramps@llamachile.tube"];
+
+            using (var store = new LayoutStore(path))
+                store.Save(new[] { new Scene { Name = "Live" } }, null, loaded);
+
+            using (var store = new LayoutStore(path))
+            {
+                store.Load();
+                var again = store.Socials;
+                Assert.NotNull(again);
+                Assert.Equal("mastodon", again!.Entries[0].FediverseSoftware);
+            }
+        }
+        finally
+        {
+            SqliteConnection.ClearAllPools();
+            if (File.Exists(path)) File.Delete(path);
+        }
+    }
+
     [Fact]
     public void SocialsConfig_RoundTrip_PersistsEntriesAndBarSettings()
     {

ytLive.Tests/SocialValidatorTests.cs

@@ -103,6 +103,39 @@ public class SocialValidatorTests
         Assert.Null(result.FediverseSoftware);
     }
 
+    [Fact]
+    public async Task FediverseSoftware_IdentityDomainSilent_ProbesWellKnownSubdomains()
+    {
+        // The identity domain is a silent landing page (no nodeinfo, no redirect);
+        // the real instance lives on mastodon.<domain> — the probe must find it.
+        var validator = Validator(new StubHandler(request =>
+        {
+            var host = request.RequestUri!.Host;
+            if (host == "mastodon.llamachile.tube")
+            {
+                if (request.RequestUri.AbsolutePath.StartsWith("/.well-known"))
+                    return Json(new { links = new[] { new { rel = "http://nodeinfo.diaspora.software/ns/schema/2.0", href = "https://mastodon.llamachile.tube/nodeinfo/2.0" } } });
+                if (request.RequestUri.AbsolutePath.StartsWith("/nodeinfo"))
+                    return Json(new { software = new { name = "mastodon", version = "4.6.3" } });
+            }
+            return new HttpResponseMessage(HttpStatusCode.NotFound);
+        }));
+
+        var software = await validator.ResolveFediverseSoftwareAsync("llamachile.tube", CancellationToken.None);
+
+        Assert.Equal("mastodon", software);
+    }
+
+    [Fact]
+    public async Task FediverseSoftware_NoSubdomainAnswers_ReturnsNull()
+    {
+        var validator = Validator(new StubHandler(new HttpResponseMessage(HttpStatusCode.NotFound)));
+
+        var software = await validator.ResolveFediverseSoftwareAsync("silent.example", CancellationToken.None);
+
+        Assert.Null(software);
+    }
+
     [Fact]
     public async Task FediverseHandle_CanceledDuringNodeInfo_IsCanceled()
     {

ytLive.Tests/SocialsDialogViewModelTests.cs

@@ -15,6 +15,9 @@ public class SocialsDialogViewModelTests
     {
         public int LookupCount { get; private set; }
 
+        public Task<string?> ResolveFediverseSoftwareAsync(string domain, CancellationToken ct)
+            => Task.FromResult<string?>("mastodon");
+
         public Task<SocialLookupResult> LookupAsync(SocialService service, string handleOrUrl, CancellationToken ct)
         {
             LookupCount++;
@@ -51,6 +54,9 @@ public class SocialsDialogViewModelTests
 
         public Task<SocialLookupResult> LookupAsync(SocialService service, string handleOrUrl, CancellationToken ct)
             => Gate.Task;
+
+        public Task<string?> ResolveFediverseSoftwareAsync(string domain, CancellationToken ct)
+            => Task.FromResult<string?>(null);
     }
 
     private sealed class SignInFake

ytLive.Tests/SourceNamingTests.cs

@@ -0,0 +1,65 @@
+using System;
+using System.Linq;
+using Microsoft.Data.Sqlite;
+using Xunit;
+using ytLive.Models;
+using ytLive.ViewModels;
+
+namespace ytLive.Tests;
+
+/// <summary>
+/// Duplicate source names get an incrementing suffix with no space (Image,
+/// Image2, Image3…) and the next free number is derived from the names actually
+/// in the scene — deleting a middle resource never collides with a survivor.
+/// Drives the real VM through the Add Source command (TextOverlay needs no
+/// dialog), the same real-App + temp-DB pattern as the round-clip test.
+/// </summary>
+[Collection("RealApp")]
+public sealed class SourceNamingTests
+{
+    private readonly RealAppHost _app;
+
+    public SourceNamingTests(RealAppHost app)
+    {
+        _app = app;
+    }
+
+    [Fact]
+    public void Duplicate_Sources_Get_Next_Free_Numbered_Name()
+    {
+        _app.Run(Run);
+    }
+
+    private void Run()
+    {
+        var tempDb = System.IO.Path.Combine(System.IO.Path.GetTempPath(), $"ytLlive-srcname-{Guid.NewGuid():N}.db");
+        MainViewModel.LayoutPathOverride = tempDb;
+        var window = new MainWindow();
+        var vm = (MainViewModel)window.DataContext;
+        try
+        {
+            var scene = vm.ActiveScene!;
+
+            vm.AddSourceCommand.Execute(SourceType.TextOverlay);
+            vm.AddSourceCommand.Execute(SourceType.TextOverlay);
+            vm.AddSourceCommand.Execute(SourceType.TextOverlay);
+
+            var names = scene.Elements.OfType<Source>().Select(s => s.Name).ToList();
+            Assert.Equal(new[] { "Text", "Text2", "Text3" }, names);
+
+            var middle = scene.Elements.OfType<Source>().Single(s => s.Name == "Text2");
+            scene.Elements.Remove(middle);
+            vm.AddSourceCommand.Execute(SourceType.TextOverlay);
+
+            var survivors = scene.Elements.OfType<Source>().Select(s => s.Name).ToList();
+            Assert.Equal(new[] { "Text", "Text3", "Text2" }, survivors);
+        }
+        finally
+        {
+            window.Close();
+            MainViewModel.LayoutPathOverride = null;
+            SqliteConnection.ClearAllPools();
+            try { System.IO.File.Delete(tempDb); } catch { /* best-effort cleanup */ }
+        }
+    }
+}

ytLive.csproj

@@ -36,6 +36,7 @@
 
   <ItemGroup>
     <PackageReference Include="Microsoft.Data.Sqlite" Version="8.0.10"/>
+    <PackageReference Include="NAudio.Wasapi" Version="2.2.1"/>
     <PackageReference Include="SQLitePCLRaw.bundle_e_sqlite3" Version="2.1.12"/>
     <PackageReference Include="System.Security.Cryptography.ProtectedData" Version="8.0.0"/>
   </ItemGroup>