refactor: split Audio out of MainViewModel — Commit 6/12

MainViewModel.Audio.cs: mic bar (AudioLevel/MeterFillWidth/MeterBrush,
MicVolume/MicMuted, ToggleMicMute, PickMicrophone), mic status dot
(MicStatus/MicStatusBrush/MicStatusToolTip), game bar
(GameAudioLevel/GameMeterFillWidth/GameMeterBrush, GameAudioVolume,
GameMuted, ToggleGameMute), PushSystemVolume, mixer event handlers
(OnMicLevelChanged/OnLoopbackLevelChanged/OnMicConnected/OnMicFailed),
StartMicCaptureAsync, command properties, 18 fields.

Kept in core: TraxIdleBrush, TRAX code block, ctor wiring
(mixer init + event hookup), timer construction.

Verify: 0 warnings, 246 passed, 2 known failures only.

ViewModels/MainViewModel.Audio.cs

@@ -0,0 +1,408 @@
+using System.Windows;
+using System.Windows.Input;
+using System.Windows.Media;
+using System.Windows.Threading;
+using NAudio.CoreAudioApi;
+using ytLive;
+using ytLive.Helpers;
+using ytLive.Models;
+using ytLive.Services;
+using ytLive.Services.Audio;
+
+namespace ytLive.ViewModels;
+
+public partial class MainViewModel
+{
+    private readonly DispatcherTimer _volumeFlashTimer;
+    private readonly DispatcherTimer _gameVolumeFlashTimer;
+    private double _audioLevel;
+    private bool _volumeAdjusting;
+    private bool _volumeFlash;
+    private double _micVolume = 0.8;
+    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 AudioGainProvider? _gainProvider;
+    private readonly IMicrophoneEnumerator _microphoneEnumerator;
+    private readonly AudioMixer _audioMixer;
+
+    public ICommand ToggleMicMuteCommand { get; }
+    public ICommand ToggleGameMuteCommand { get; }
+    public ICommand OpenMicPickerCommand { get; }
+
+    // ─── 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>
+    public double AudioLevel
+    {
+        get => _audioLevel;
+        set
+        {
+            if (SetProperty(ref _audioLevel, Math.Clamp(value, 0, 1)))
+            {
+                OnPropertyChanged(nameof(MeterFillWidth));
+                OnPropertyChanged(nameof(MeterBrush));
+            }
+        }
+    }
+
+    /// <summary>Displayed meter level: 0 while muted; the volume position while
+    /// the slider is being dragged (or briefly after an unmute, so the restored
+    /// 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, AudioLevelMeter.ToDisplay((float)AudioLevel) * 1.2 * MicVolume);
+
+    public double MeterFillWidth => MeterLevel * 288;
+
+    public string MeterBrush => MeterLevel switch
+    {
+        < 0.6 => "#22c55e",
+        < 0.8 => "#eab308",
+        _ => "#ef4444",
+    };
+
+    /// <summary>Previewes the volume position while the slider is dragged; the
+    /// bar returns to the live level on release (empty when there is no input).
+    /// Starting a drag cancels any pending unmute flash.</summary>
+    public void SetVolumeAdjusting(bool adjusting)
+    {
+        if (adjusting)
+            CancelVolumeFlash();
+        if (SetProperty(ref _volumeAdjusting, adjusting))
+        {
+            OnPropertyChanged(nameof(MeterFillWidth));
+            OnPropertyChanged(nameof(MeterBrush));
+        }
+    }
+
+    private void BeginVolumeFlash()
+    {
+        _volumeFlash = true;
+        OnPropertyChanged(nameof(MeterFillWidth));
+        OnPropertyChanged(nameof(MeterBrush));
+        _volumeFlashTimer.Stop();
+        _volumeFlashTimer.Start();
+    }
+
+    private void EndVolumeFlash()
+    {
+        _volumeFlashTimer.Stop();
+        if (_volumeFlash)
+        {
+            _volumeFlash = false;
+            OnPropertyChanged(nameof(MeterFillWidth));
+            OnPropertyChanged(nameof(MeterBrush));
+        }
+    }
+
+    private void CancelVolumeFlash()
+    {
+        _volumeFlashTimer.Stop();
+        _volumeFlash = false;
+    }
+
+    /// <summary>Mic gain (0..1). Running to 0 mutes (the speaker flips to muted);
+    /// moving up from 0 unmutes (the mute indicator clears). The level being left
+    /// is remembered so the speaker button can restore it.</summary>
+    public double MicVolume
+    {
+        get => _micVolume;
+        set
+        {
+            var clamped = Math.Clamp(value, 0, 1);
+            if (clamped == 0 && !_micMuted)
+                _volumeBeforeMute ??= _micVolume;
+            if (SetProperty(ref _micVolume, clamped))
+            {
+                var muted = clamped == 0;
+                if (_micMuted != muted)
+                {
+                    _micMuted = muted;
+                    OnPropertyChanged(nameof(MicMuted));
+                    OnPropertyChanged(nameof(MicMuteText));
+                }
+                if (!muted)
+                    _volumeBeforeMute = null;
+                OnPropertyChanged(nameof(MeterFillWidth));
+                OnPropertyChanged(nameof(MeterBrush));
+            }
+        }
+    }
+
+    /// <summary>Read-only: true whenever the volume is 0. Only MicVolume may
+    /// change it, so the slider and the speaker can never disagree.</summary>
+    public bool MicMuted => _micMuted;
+
+    public string MicMuteText => MicMuted ? "Unmute" : "Mute";
+
+    /// <summary>Name of the picked voice source, shown left-justified INSIDE the meter
+    /// bar (FontSize 10, ellipsized to the bar) — ai.md is the authority here.</summary>
+    public string? MicSourceName
+    {
+        get => _micSourceName;
+        private set => SetProperty(ref _micSourceName, value);
+    }
+
+    private void ToggleMicMute()
+    {
+        if (MicMuted)
+        {
+            MicVolume = _volumeBeforeMute ?? 0.8;
+            BeginVolumeFlash();
+        }
+        else
+        {
+            _volumeBeforeMute = MicVolume;
+            MicVolume = 0;
+        }
+    }
+
+    private void PickMicrophone()
+    {
+        var dialog = new MicPickerDialog(new MicPickerViewModel(_microphoneEnumerator))
+        {
+            Owner = System.Windows.Application.Current?.MainWindow
+        };
+        if (dialog.ShowDialog() == true && dialog.PickedDevice != null)
+        {
+            MicSourceName = dialog.PickedDevice.DisplayName;
+            _layoutStore.SaveMicSourceName(MicSourceName); // persist across restarts
+            _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): always visible — a mirror of the mic bar
+    // ─── (meter + mute + volume). Desktop/game audio is automatic (WASAPI loopback). ───
+    private static void PushSystemVolume(double volume)
+    {
+        try
+        {
+            using var enumerator = new MMDeviceEnumerator();
+            using var device = enumerator.GetDefaultAudioEndpoint(DataFlow.Render, Role.Multimedia);
+            device.AudioEndpointVolume.MasterVolumeLevelScalar = (float)volume;
+        }
+        catch { }
+    }
+
+    /// <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));
+
+    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));
+                UpdateTraxLocalGain();
+                PushSystemVolume(clamped);
+            }
+        }
+    }
+
+    /// <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;
+        }
+    }
+    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");
+                _notifications.Warning("No microphone found",
+                    "Mic capture wasn't started — plug one in and pick it from the mixer.");
+                return;
+            }
+            _audioMixer.Start();
+        }
+        catch (Exception ex)
+        {
+            AppLog.Write($"Mic: device check failed: {ex.Message}");
+        }
+    }
+}

ViewModels/MainViewModel.cs

@@ -27,25 +27,9 @@ public partial class MainViewModel : ViewModelBase
     private readonly YouTubeStreamService _youtubeStream;
     private readonly YouTubeChatService _youtubeChat;
     private readonly DispatcherTimer _liveTimer;
-    private readonly DispatcherTimer _volumeFlashTimer;
-    private readonly DispatcherTimer _gameVolumeFlashTimer;
     private readonly DispatcherTimer _healthPollTimer;
 
     private SceneElement? _selectedElement;
-    private double _audioLevel;
-    private bool _volumeAdjusting;
-    private bool _volumeFlash;
-    private double _micVolume = 0.8;
-    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;
 
     // TRAX (TASK 9): free background music at a fixed quiet volume, playing to
     // the default device so it rides the loopback into the stream. The dot is
@@ -53,7 +37,6 @@ public partial class MainViewModel : ViewModelBase
     private readonly MusicPlayer _musicPlayer = new();
     private Music? _music;
     private bool _musicPlaying;
-    private AudioGainProvider? _gainProvider;
     private StreamStatus _streamStatus = StreamStatus.Offline;
     private StreamHealth _currentHealth = new();
     private string _streamTitle = string.Empty;
@@ -108,15 +91,6 @@ public partial class MainViewModel : ViewModelBase
 
     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
@@ -260,190 +234,7 @@ public partial class MainViewModel : ViewModelBase
         }
     }
 
-    // ─── 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>
-    public double AudioLevel
-    {
-        get => _audioLevel;
-        set
-        {
-            if (SetProperty(ref _audioLevel, Math.Clamp(value, 0, 1)))
-            {
-                OnPropertyChanged(nameof(MeterFillWidth));
-                OnPropertyChanged(nameof(MeterBrush));
-            }
-        }
-    }
-
-    /// <summary>Displayed meter level: 0 while muted; the volume position while
-    /// the slider is being dragged (or briefly after an unmute, so the restored
-    /// 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, AudioLevelMeter.ToDisplay((float)AudioLevel) * 1.2 * MicVolume);
-
-    public double MeterFillWidth => MeterLevel * 288;
-
-    public string MeterBrush => MeterLevel switch
-    {
-        < 0.6 => "#22c55e",
-        < 0.8 => "#eab308",
-        _ => "#ef4444",
-    };
-
-    /// <summary>Previewes the volume position while the slider is dragged; the
-    /// bar returns to the live level on release (empty when there is no input).
-    /// Starting a drag cancels any pending unmute flash.</summary>
-    public void SetVolumeAdjusting(bool adjusting)
-    {
-        if (adjusting)
-            CancelVolumeFlash();
-        if (SetProperty(ref _volumeAdjusting, adjusting))
-        {
-            OnPropertyChanged(nameof(MeterFillWidth));
-            OnPropertyChanged(nameof(MeterBrush));
-        }
-    }
-
-    private void BeginVolumeFlash()
-    {
-        _volumeFlash = true;
-        OnPropertyChanged(nameof(MeterFillWidth));
-        OnPropertyChanged(nameof(MeterBrush));
-        _volumeFlashTimer.Stop();
-        _volumeFlashTimer.Start();
-    }
-
-    private void EndVolumeFlash()
-    {
-        _volumeFlashTimer.Stop();
-        if (_volumeFlash)
-        {
-            _volumeFlash = false;
-            OnPropertyChanged(nameof(MeterFillWidth));
-            OnPropertyChanged(nameof(MeterBrush));
-        }
-    }
-
-    private void CancelVolumeFlash()
-    {
-        _volumeFlashTimer.Stop();
-        _volumeFlash = false;
-    }
-
-    /// <summary>Mic gain (0..1). Running to 0 mutes (the speaker flips to muted);
-    /// moving up from 0 unmutes (the mute indicator clears). The level being left
-    /// is remembered so the speaker button can restore it.</summary>
-    public double MicVolume
-    {
-        get => _micVolume;
-        set
-        {
-            var clamped = Math.Clamp(value, 0, 1);
-            if (clamped == 0 && !_micMuted)
-                _volumeBeforeMute ??= _micVolume;
-            if (SetProperty(ref _micVolume, clamped))
-            {
-                var muted = clamped == 0;
-                if (_micMuted != muted)
-                {
-                    _micMuted = muted;
-                    OnPropertyChanged(nameof(MicMuted));
-                    OnPropertyChanged(nameof(MicMuteText));
-                }
-                if (!muted)
-                    _volumeBeforeMute = null;
-                OnPropertyChanged(nameof(MeterFillWidth));
-                OnPropertyChanged(nameof(MeterBrush));
-            }
-        }
-    }
-
-    /// <summary>Read-only: true whenever the volume is 0. Only MicVolume may
-    /// change it, so the slider and the speaker can never disagree.</summary>
-    public bool MicMuted => _micMuted;
-
-    public string MicMuteText => MicMuted ? "Unmute" : "Mute";
-
-    /// <summary>Name of the picked voice source, shown left-justified INSIDE the meter
-    /// bar (FontSize 10, ellipsized to the bar) — ai.md is the authority here.</summary>
-    public string? MicSourceName
-    {
-        get => _micSourceName;
-        private set => SetProperty(ref _micSourceName, value);
-    }
-
-    private void ToggleMicMute()
-    {
-        if (MicMuted)
-        {
-            MicVolume = _volumeBeforeMute ?? 0.8;
-            BeginVolumeFlash();
-        }
-        else
-        {
-            _volumeBeforeMute = MicVolume;
-            MicVolume = 0;
-        }
-    }
-
-    private void PickMicrophone()
-    {
-        var dialog = new MicPickerDialog(new MicPickerViewModel(_microphoneEnumerator))
-        {
-            Owner = System.Windows.Application.Current?.MainWindow
-        };
-        if (dialog.ShowDialog() == true && dialog.PickedDevice != null)
-        {
-            MicSourceName = dialog.PickedDevice.DisplayName;
-            _layoutStore.SaveMicSourceName(MicSourceName); // persist across restarts
-            _audioMixer.RestartMic(); // swap the live device immediately
-        }
-    }
-
-    // ─── Mic status dot (the MIC button) ───
-
-    private static readonly SolidColorBrush MicProblemBrush = CreateBrush("#f1c40f");
     private static readonly SolidColorBrush TraxIdleBrush = CreateBrush("#555");
-
-    /// <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): always visible — a mirror of the mic bar
-    // ─── (meter + mute + volume). Desktop/game audio is automatic (WASAPI loopback). ───
-
     /// <summary>True while the TRAX background track is playing.</summary>
     public bool IsMusicPlaying
     {
@@ -557,131 +348,6 @@ public partial class MainViewModel : ViewModelBase
         _musicPlayer.LocalGain = GameMuted ? 0f : 1f;
     }
 
-    private static void PushSystemVolume(double volume)
-    {
-        try
-        {
-            using var enumerator = new MMDeviceEnumerator();
-            using var device = enumerator.GetDefaultAudioEndpoint(DataFlow.Render, Role.Multimedia);
-            device.AudioEndpointVolume.MasterVolumeLevelScalar = (float)volume;
-        }
-        catch { }
-    }
-
-    /// <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));
-
-    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));
-                UpdateTraxLocalGain();
-                PushSystemVolume(clamped);
-            }
-        }
-    }
-
-    /// <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;
@@ -1041,9 +707,6 @@ public partial class MainViewModel : ViewModelBase
     public ICommand RemoveSourceCommand { get; }
     public ICommand EditElementCommand { get; }
     public ICommand ToggleElementVisibilityCommand { get; }
-    public ICommand ToggleMicMuteCommand { get; }
-    public ICommand ToggleGameMuteCommand { get; }
-    public ICommand OpenMicPickerCommand { get; }
     public ICommand OpenSocialDialogCommand { get; }
     public ICommand StartStreamCommand { get; }
     public ICommand EndStreamCommand { get; }
@@ -2083,68 +1746,6 @@ public partial class MainViewModel : ViewModelBase
             : Environment.GetFolderPath(Environment.SpecialFolder.MyVideos);
     }
 
-    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");
-                _notifications.Warning("No microphone found",
-                    "Mic capture wasn't started — plug one in and pick it from the mixer.");
-                return;
-            }
-            _audioMixer.Start();
-        }
-        catch (Exception ex)
-        {
-            AppLog.Write($"Mic: device check failed: {ex.Message}");
-        }
-    }
 
     // Scene-element → latest frame, for the live compositor. The map mirrors the
     // preview: webcam by DeviceId, live captures (the background) by CaptureKey,

ViewModels/index.md

@@ -57,13 +57,24 @@ Progress (Commit N/12 · tag):
   `CanChangeWebcam`/`CanShowWebcamInStagedScene`/`IsWebcamSelected`/`WebcamError`,
   size safeguard `WebcamMax*`/`ClampWebcamToBounds`/`HealLegacySquareRect`,
   `AddWebcamCommand`/`ChangeWebcamCommand`/`ShowWebcamCommand`).
+- **Commit 6/12 · `refactor-commit-6`: Audio landed** → `MainViewModel.Audio.cs`
+  (mic bar `AudioLevel`/`MeterFillWidth`/`MeterBrush`/`MicVolume`/`MicMuted`/
+  `MicMuteText`/`MicSourceName`/`ToggleMicMute`/`PickMicrophone`, volume flash
+  `SetVolumeAdjusting`/`BeginVolumeFlash`/`EndVolumeFlash`/`CancelVolumeFlash`,
+  mic status dot `MicStatus`/`MicStatusBrush`/`MicStatusToolTip`/`MicProblemBrush`,
+  game bar `GameAudioLevel`/`GameMeterLevel`/`GameMeterFillWidth`/`GameMeterBrush`/
+  `SetGameVolumeAdjusting`/`GameAudioVolume`/`GameMuted`/`GameMuteText`/
+  `ToggleGameMute`, `PushSystemVolume`, mixer handlers `OnMicLevelChanged`/
+  `OnLoopbackLevelChanged`/`OnMicConnected`/`OnMicFailed`, `StartMicCaptureAsync`,
+  audio fields + `ToggleMicMuteCommand`/`ToggleGameMuteCommand`/`OpenMicPickerCommand`).
+  TRAX stays in core (next commit).
 
 - Core file keeps: fields, ctor, `Shutdown`/`SaveLayoutNow`/`ScheduleSave`/`LoadLayout`,
   `SetPanel`/`ShowOverlay`/`ShowLicenses`, `CreateBrush`, `OpenUrl`/`ComposeEmail`,
   `SubmitBug`/`SubmitFeature`, window-geometry pass-through.
 - Partials: `Account` ✔ (Commit 1), `License` ✔ (Commit 2), `Scenes` ✔ (Commit 3), `Background` ✔ (Commit 4),
-  `Webcam` ✔ (Commit 5),
+  `Webcam` ✔ (Commit 5), `Audio` ✔ (Commit 6),
-  `Audio` (mic + game bars + TRAX), `Trax` (music player), `Socials` (social bar + dialog),
+  `Trax` (music player), `Socials` (social bar + dialog),
   `Streaming` (go-live/record + health + quality tiers + media source pipeline),
   `Chat` (YouTube chat + mock preview + chatbox render), `Overlays` (settings/bug/feature/about
   panels + license entry).