TASK 4 audio fixes round 2: dB-scaled meters, game bar moved into the preview, Notepad About button replaced by the logo → in-app About — AudioLevelMeter.ToDisplay maps -60..0 dBFS onto 0..1 (real speech/game RMS ~0.01..0.1 linear left the flat scale dead; both meters now scale through it before volume); the game audio bar moved OUT of the footer (back to two rows) and is now a bottom-center dark chip overlaid on the preview window — monitoring UI only, never on the live output; the top-bar About button (opened THIRD-PARTY-NOTICES.txt in the OS viewer) removed, the ytLlive wordmark now opens the in-app About overlay, and task 21 queued (real logo + creator-hub About with premium/coffee/socials links + in-app scrolling licensing panel) — 169 tests passing, 0 warnings

HANDOFF.md

@@ -7,28 +7,30 @@
 
 ## Session state (last updated: 2026-08-13)
 
-- **Branch:** `main`. The **game audio bar + mic status dot + always-on capture**
+- **Branch:** `main`. The **audio UX follow-up** (`9f9ed34`) is **committed and pushed**.
-  work is **uncommitted** (see list below). The last committed+pushed baseline is
+- **This session (round 2 — the game audio bar + meter fixes):**
-  `ea250c0` (social bar click-toggle).
+  1. **Meter scaling:** the bars looked dead on a flat scale — real speech/game RMS is
-- **This session (audio UX follow-up):** per the creator's requests —
+     ~0.01..0.1 linear, so the fill barely moved even at full volume. Added
-  1. The MIC label is now a **button with a status dot** (`Models/MicStatus`:
+     `AudioLevelMeter.ToDisplay(float)`: maps −60..0 dBFS linearly onto 0..1. Both meters
-     green = capturing, yellow = requested mic problem, red = no device).
+     (mic `MeterLevel`, game `GameMeterLevel`) now scale the raw level through it before
-  2. **Mic capture runs for the app's lifetime** (started at startup via
+     multiplying by volume. +2 unit tests.
-     `StartMicCaptureAsync`, disposed in `Shutdown`; `BeginGoLive`/`StopStream`
+  2. **Game bar placement correction (user: it belongs in the preview, not the footer):**
-     no longer start/stop the mixer) so both meters preview live.
+     moved the game audio bar OUT of the footer (footer back to two rows) and into the
-  3. A **game audio bar** (desktop/game — meter + mute + volume, mirror of the
+     **preview window** as a bottom-center dark chip overlaid on the live display
-     mic bar) sits centered beneath the preview and appears only while a
+     (`MainWindow.xaml`, in the `PreviewGrid` next to the OpacityChip). Monitoring UI
-     **full-screen game is producing sound** (decision: fullscreen + loopback
+     only — never rendered into the live output (the `SceneCompositor` is unaware of it).
-     sound; **silence never hides an active bar** — the creator's final rule).
+  3. **About button (user: stop jacking Notepad; standalone app):** the top-bar About
-     Show after ~500ms of fullscreen+sound, hide ~1s after leaving fullscreen.
+     button that opened `THIRD-PARTY-NOTICES.txt` in the OS viewer is GONE (button +
-- **Uncommitted files:** `MainWindow.xaml`/`.cs`, `ViewModels/MainViewModel.cs`,
+     `AboutButton_Click` removed). The **ytLlive wordmark (top-left) is now clickable**
-  `Services/Audio/{IAudioSource,WasapiMicAudioSource,WasapiLoopbackAudioSource,AudioMixer}.cs`,
+     and opens the existing in-app About overlay (`OpenAboutCommand`). Queued as task 21:
-  new `Models/MicStatus.cs`, new `Services/{IGameAudioDetector,GameAudioHysteresis,GameAudioDetector}.cs`,
+     make a real logo + expand the About overlay into the creator's hub (premium / coffee
-  `ytLive.Tests/AudioMixerTests.cs`, new `GameAudioHysteresisTests.cs` +
+     / socials links + a scrolling licensing/legal panel, all in-app).
-  `GameAudioDetectorTests.cs`, memory docs (TASKS.md, ai.md, Services/index.md,
+- **Uncommitted:** this round-2 work — `Services/Audio/AudioLevelMeter.cs`,
-  ViewModels/index.md, Models/index.md, HANDOFF).
+  `ViewModels/MainViewModel.cs`, `MainWindow.xaml` (scaling + game bar + logo/About),
-- **Verified:** build 0 warnings, 0 errors; **167 tests passing** (full suite,
+  `MainWindow.xaml.cs` (AboutButton_Click + unused usings removed), `ytLive.Tests/AudioMixerTests.cs`
-  after the final rebuild).
+  (2 new `ToDisplay` tests), memory docs (TASKS.md — incl. new task 21, ai.md,
+  Services/index.md, ViewModels/index.md, HANDOFF, THIRD-PARTY-NOTICES.txt).
+- **Verified:** build 0 warnings, 0 errors; **169 tests passing** (full suite).
 - **Landmines:**
   - Never set a local `Canvas.SetTop` on the social bar — a local value permanently
     overrides `{Binding SocialBarTop}` (the `ClearValue` lesson from 5.5).

MainWindow.xaml

@@ -86,10 +86,17 @@
                     <ColumnDefinition Width="Auto"/>
                 </Grid.ColumnDefinitions>
 
-                <!-- Logo / Brand -->
+                <!-- Logo / Brand — clicking opens the in-app About overlay -->
-                <TextBlock Grid.Column="0" Text="ytLlive"
+                <Button Grid.Column="0" Background="Transparent" BorderThickness="0" Cursor="Hand"
-                           Foreground="#e94560" FontSize="22" FontWeight="Bold"
+                        VerticalAlignment="Center" Margin="0,0,24,0" ToolTip="About ytLlive"
-                           VerticalAlignment="Center" Margin="0,0,24,0"/>
+                        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) -->
                 <StackPanel Grid.Column="1" Orientation="Horizontal"
@@ -105,8 +112,6 @@
 
                 <!-- 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}"
@@ -744,6 +749,63 @@
                                            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>
@@ -795,15 +857,14 @@
                 <Grid.RowDefinitions>
                     <RowDefinition Height="Auto"/>
                     <RowDefinition Height="Auto"/>
-                    <RowDefinition Height="Auto"/>
                 </Grid.RowDefinitions>
 
                 <!-- 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 (WASAPI loopback
-                     at unity); the creator's controls are the two meters — the mic
+                     at unity); the mic meter is the creator's only footer audio
-                     (always visible, with its status dot) and the game bar (appears
+                     control (the game audio bar lives INSIDE the preview window,
-                     only while a full-screen game is producing sound). -->
+                     overlaid at its bottom edge while a full-screen game is up). -->
                 <Grid Grid.Row="0">
                     <Grid.ColumnDefinitions>
                         <ColumnDefinition Width="220"/>
@@ -951,58 +1012,6 @@
                         </Button>
                     </StackPanel>
                 </Grid>
-
-                <!-- Line 3: game/desktop audio — meter + volume + mute, centered
-                     beneath the preview (a mirror of the mic bar). Appears only
-                     while a full-screen game is producing sound (the game audio
-                     detector); desktop audio itself is automatic WASAPI loopback. -->
-                <StackPanel Grid.Row="2" Orientation="Horizontal" Margin="0,6,0,0"
-                            HorizontalAlignment="Center" VerticalAlignment="Center"
-                            Visibility="{Binding IsGameAudioBarVisible, Converter={StaticResource BoolToVis}}">
-                    <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>
             </Grid>
         </Border>
 

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;
@@ -145,21 +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)

Services/Audio/AudioLevelMeter.cs

@@ -13,6 +13,20 @@ public sealed class AudioLevelMeter
 
     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)

Services/index.md

@@ -49,7 +49,7 @@ External-facing logic: YouTube API, persistence. See
 | `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` |
+| `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)` |

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). **Post-test follow-up (2026-08-13, game audio bar branch):** the footer is now THREE lines — a **game audio bar** (desktop/game, a mirror of the mic bar: meter + mute + volume) sits centered beneath the mic bar 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 both 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. 167 tests passing, 0 warnings
+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
 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 +115,7 @@ 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
 
 ### The Minimal Source Set (design decision — do not expand casually)
 
@@ -336,8 +337,8 @@ 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
+   output. *(Surfacing changed on 2026-08-13: the top-bar About button that opened the file in the OS
-   OS viewer).
+   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
@@ -355,8 +356,8 @@ 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
+staging dir). `THIRD-PARTY-NOTICES.txt` (repo root) ships to the build output; the "never do" licensing
-top-bar **About** button; the "never do" licensing guardrails are recorded in `ai.md` — build **0 warnings**.
+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**.

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
+If this file changes, update it here AND in the app's About screen (the About
-this file). See TASKS.md (TASK 4) and ai.md ("Licensing — do not violate") for
+overlay's licensing panel surfaces this file in-app). See TASKS.md (TASK 4) and
-the guardrails — the "never do" list is there on purpose.
+ai.md ("Licensing — do not violate") for the guardrails — the "never do" list is
+there on purpose.
 
 --------------------------------------------------------------------------------
 

ViewModels/MainViewModel.cs

@@ -309,7 +309,7 @@ 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;
 
@@ -494,7 +494,7 @@ public class MainViewModel : ViewModelBase
     /// <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, GameAudioLevel * GameAudioVolume);
+    private double GameMeterLevel => GameMuted ? 0 : _gameVolumeAdjusting || _gameVolumeFlash ? GameAudioVolume : Math.Min(1, AudioLevelMeter.ToDisplay((float)GameAudioLevel) * GameAudioVolume);
 
     public double GameMeterFillWidth => GameMeterLevel * 288;
 

ai.md

@@ -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). 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)
@@ -371,10 +371,12 @@ devices, no timers).
   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 both footer meters preview live (`BeginGoLive`/`StopStream`
+  `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`. **Mic connection state
+  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
@@ -388,11 +390,14 @@ devices, no timers).
   ~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`.
+  `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**; **167 passing** (mixer/hysteresis/game-detector unit tests).
+- 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).

ytLive.Tests/AudioMixerTests.cs

@@ -324,6 +324,26 @@ public class AudioLevelMeterTests
 
         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