Port managed client audio and Windows application

clients/windows/VoiceCat.App/Audio/InputDeviceCapture.cs

@@ -16,7 +16,7 @@ public sealed record InputDeviceInfo(string Id, string Name, bool IsDefault)
 /// the aux device is opened client-side and needs a WASAPI id, not a miniaudio one.</summary>
 public static class InputDeviceEnumerator
 {
-    public static IReadOnlyList<InputDeviceInfo> List()
+    public static IReadOnlyList<InputDeviceInfo> List(bool input = true)
     {
         var result = new List<InputDeviceInfo>();
         InputDeviceCapture.IMMDeviceEnumerator? enumerator = null;
@@ -29,7 +29,7 @@ public static class InputDeviceEnumerator
                 Type.GetTypeFromCLSID(new Guid("BCDE0395-E52F-467C-8E3D-C4579291692E"))!)!;
 
             // Resolve the default capture endpoint id so the picker can flag it.
-            if (enumerator.GetDefaultAudioEndpoint(1 /*eCapture*/, 0 /*eConsole*/,
+            if (enumerator.GetDefaultAudioEndpoint(input ? 1 : 0, 0 /*eConsole*/,
                     out var defDev) == 0 && defDev != null)
             {
                 try { if (defDev.GetId(out string id) == 0) defaultId = id; }
@@ -37,7 +37,7 @@ public static class InputDeviceEnumerator
             }
 
             // DEVICE_STATE_ACTIVE = 0x1 — only currently-usable endpoints.
-            if (enumerator.EnumAudioEndpoints(1 /*eCapture*/, 0x1, out collectionPtr) != 0
+            if (enumerator.EnumAudioEndpoints(input ? 1 : 0, 0x1, out collectionPtr) != 0
                 || collectionPtr == IntPtr.Zero)
                 return result;
 
@@ -107,6 +107,7 @@ public sealed class InputDeviceCapture : IDisposable
     private const int FrameSamples = 960;  // 20 ms
 
     private readonly string? _deviceId;  // null = system default capture endpoint
+    private readonly bool _loopback;
 
     private IAudioClient?        _audioClient;
     private IAudioCaptureClient? _captureClient;
@@ -123,8 +124,9 @@ public sealed class InputDeviceCapture : IDisposable
     // Init-done signal: Set() by the capture thread after activation completes.
     private readonly ManualResetEventSlim _initDone = new(false);
     private bool _initOk;
+    private int _disposed;
 
-    public InputDeviceCapture(string? deviceId) => _deviceId = deviceId;
+    public InputDeviceCapture(string? deviceId, bool loopback = false) { _deviceId = deviceId; _loopback = loopback; }
 
     /// <summary>Starts capture. Blocks until WASAPI activation completes (typically &lt;100 ms).
     /// Returns false if the device cannot be opened.</summary>
@@ -148,15 +150,13 @@ public sealed class InputDeviceCapture : IDisposable
     {
         _running = false;
         _bufferEvent?.Set();
-        _captureThread?.Join(500);
-        try { _audioClient?.Stop(); } catch { /* device already gone */ }
+        if (_captureThread is not null && !_captureThread.Join(5000)) throw new TimeoutException("Capture did not stop.");
     }
 
     public void Dispose()
     {
+        if (Interlocked.Exchange(ref _disposed, 1) != 0) return;
         Stop();
-        if (_captureClient != null) { Marshal.ReleaseComObject(_captureClient); _captureClient = null; }
-        if (_audioClient   != null) { Marshal.ReleaseComObject(_audioClient);   _audioClient   = null; }
         _bufferEvent?.Dispose();
         _initDone.Dispose();
     }
@@ -165,10 +165,19 @@ public sealed class InputDeviceCapture : IDisposable
 
     private void CaptureThreadProc()
     {
-        _initOk = ActivateAndStart();
-        _initDone.Set();
-        if (!_initOk) return;
-        CaptureLoop();
+        try
+        {
+            _initOk = ActivateAndStart();
+            _initDone.Set();
+            if (_initOk && _running) CaptureLoop();
+        }
+        catch { _initOk = false; _initDone.Set(); }
+        finally
+        {
+            try { _audioClient?.Stop(); } catch { }
+            if (_captureClient != null) { Marshal.ReleaseComObject(_captureClient); _captureClient = null; }
+            if (_audioClient != null) { Marshal.ReleaseComObject(_audioClient); _audioClient = null; }
+        }
     }
 
     private bool ActivateAndStart()
@@ -192,7 +201,7 @@ public sealed class InputDeviceCapture : IDisposable
                 Type.GetTypeFromCLSID(new Guid("BCDE0395-E52F-467C-8E3D-C4579291692E"))!)!;
 
             int hr = _deviceId is null
-                ? enumerator.GetDefaultAudioEndpoint(1 /*eCapture*/, 0 /*eConsole*/, out device)
+                ? enumerator.GetDefaultAudioEndpoint(_loopback ? 0 : 1, 0 /*eConsole*/, out device)
                 : enumerator.GetDevice(_deviceId, out device);
             if (hr != 0 || device == null) return false;
 
@@ -220,7 +229,7 @@ public sealed class InputDeviceCapture : IDisposable
         //   AUDCLNT_STREAMFLAGS_EVENTCALLBACK    = 0x00040000
         //   AUDCLNT_STREAMFLAGS_AUTOCONVERTPCM   = 0x80000000
         //   AUDCLNT_STREAMFLAGS_SRC_DEFAULT_QUALITY = 0x08000000
-        const uint streamFlags = 0x00040000u | 0x80000000u | 0x08000000u;
+        uint streamFlags = 0x00040000u | 0x80000000u | 0x08000000u | (_loopback ? 0x00020000u : 0u);
 
         foreach (int ch in new[] { 2, 1 })
         {
@@ -327,9 +336,7 @@ public sealed class InputDeviceCapture : IDisposable
 
     private void FlushFrame()
     {
-        var copy = new short[_accumBuf.Length];
-        _accumBuf.AsSpan().CopyTo(copy);
-        PcmFrameReady?.Invoke(copy, FrameSamples, _channels);
+        PcmFrameReady?.Invoke(_accumBuf, FrameSamples, _channels); // Borrowed until callback returns.
         _accumCount = 0;
     }