Sound cleanup.

BizHawk.Client.EmuHawk/BizHawk.Client.EmuHawk.csproj

@@ -717,6 +717,7 @@
     <Compile Include="RomStatusPicker.Designer.cs">
       <DependentUpon>RomStatusPicker.cs</DependentUpon>
     </Compile>
+    <Compile Include="Sound\Interfaces\ISoundOutput.cs" />
     <Compile Include="Sound\Output\DirectSoundSoundOutput.cs" />
     <Compile Include="Sound\Output\DummySoundOutput.cs" />
     <Compile Include="Sound\Output\OpenALSoundOutput.cs" />

BizHawk.Client.EmuHawk/Sound/Interfaces/ISoundOutput.cs

@@ -0,0 +1,14 @@
+using System;
+
+namespace BizHawk.Client.EmuHawk
+{
+	public interface ISoundOutput : IDisposable
+	{
+		void StartSound();
+		void StopSound();
+		void ApplyVolumeSettings(double volume);
+		int MaxSamplesDeficit { get; }
+		int CalculateSamplesNeeded();
+		void WriteSamples(short[] samples, int sampleCount);
+	}
+}

BizHawk.Client.EmuHawk/Sound/Sound.cs

@@ -15,10 +15,9 @@ namespace BizHawk.Client.EmuHawk
 
 		private bool _disposed;
 		private readonly ISoundOutput _outputDevice;
-		private readonly SoundOutputProvider _outputProvider = new SoundOutputProvider();
+		private readonly SoundOutputProvider _outputProvider = new SoundOutputProvider(); // Buffer for Sync sources
-		private readonly BufferedAsync _bufferedAsync = new BufferedAsync();
+		private readonly BufferedAsync _bufferedAsync = new BufferedAsync(); // Buffer for Async sources
-		private ISoundProvider _sourceProvider;
+		private IBufferedSoundProvider _bufferedProvider; // One of the preceding buffers, or null if no source is set
-		private SyncSoundMode _syncMode;
 
 		public Sound(IntPtr mainWindowHandle)
 		{
@@ -71,8 +70,7 @@ namespace BizHawk.Client.EmuHawk
 
 			_outputDevice.StopSound();
 
-			_outputProvider.DiscardSamples();
+			if (_bufferedProvider != null) _bufferedProvider.DiscardSamples();
-			_bufferedAsync.DiscardSamples();
 
 			Global.SoundMaxBufferDeficitMs = 0;
 
@@ -86,28 +84,27 @@ namespace BizHawk.Client.EmuHawk
 		/// </summary>
 		public void SetInputPin(ISoundProvider source)
 		{
-			_outputProvider.DiscardSamples();
+			if (_bufferedProvider != null)
-			_outputProvider.BaseSoundProvider = null;
-
-			_bufferedAsync.DiscardSamples();
-			_bufferedAsync.BaseSoundProvider = null;
-
-			_sourceProvider = source;
-			if (_sourceProvider == null)
 			{
-				return;
+				_bufferedProvider.BaseSoundProvider = null;
+				_bufferedProvider.DiscardSamples();
+				_bufferedProvider = null;
 			}
 
-			_syncMode = _sourceProvider.SyncMode;
+			if (source == null) return;
-			if (_syncMode == SyncSoundMode.Sync)
+
+			if (source.SyncMode == SyncSoundMode.Sync)
 			{
-				_outputProvider.BaseSoundProvider = _sourceProvider;
+				_bufferedProvider = _outputProvider;
 			}
-			else
+			else if (source.SyncMode == SyncSoundMode.Async)
 			{
-				_bufferedAsync.BaseSoundProvider = _sourceProvider;
 				_bufferedAsync.RecalculateMagic(Global.Emulator.CoreComm.VsyncRate);
+				_bufferedProvider = _bufferedAsync;
 			}
+			else throw new InvalidOperationException("Unsupported sync mode.");
+
+			_bufferedProvider.BaseSoundProvider = source;
 		}
 
 		public bool LogUnderruns { get; set; }
@@ -148,18 +145,12 @@ namespace BizHawk.Client.EmuHawk
 
 		public void UpdateSound(float atten)
 		{
-			if (!Global.Config.SoundEnabled || !IsStarted || _sourceProvider == null || _disposed)
+			if (!Global.Config.SoundEnabled || !IsStarted || _bufferedProvider == null || _disposed)
 			{
-				if (_sourceProvider != null) _sourceProvider.DiscardSamples();
+				if (_bufferedProvider != null) _bufferedProvider.DiscardSamples();
-				_outputProvider.DiscardSamples();
 				return;
 			}
 
-			if (_sourceProvider.SyncMode != _syncMode)
-			{
-				throw new Exception("Sync mode changed unexpectedly.");
-			}
-
 			if (atten < 0) atten = 0;
 			if (atten > 1) atten = 1;
 			_outputDevice.ApplyVolumeSettings(atten);
@@ -173,14 +164,13 @@ namespace BizHawk.Client.EmuHawk
 				samples = new short[samplesNeeded * ChannelCount];
 				samplesProvided = samplesNeeded;
 
-				_sourceProvider.DiscardSamples();
+				_bufferedProvider.DiscardSamples();
-				_outputProvider.DiscardSamples();
 			}
-			else if (_syncMode == SyncSoundMode.Sync)
+			else if (_bufferedProvider == _outputProvider)
 			{
 				if (Global.Config.SoundThrottle)
 				{
-					_sourceProvider.GetSamplesSync(out samples, out samplesProvided);
+					_outputProvider.BaseSoundProvider.GetSamplesSync(out samples, out samplesProvided);
 
 					while (samplesNeeded < samplesProvided && !Global.DisableSecondaryThrottling)
 					{
@@ -197,7 +187,7 @@ namespace BizHawk.Client.EmuHawk
 					_outputProvider.GetSamples(samplesNeeded, out samples, out samplesProvided);
 				}
 			}
-			else if (_syncMode == SyncSoundMode.Async)
+			else if (_bufferedProvider == _bufferedAsync)
 			{
 				samples = new short[samplesNeeded * ChannelCount];
 
@@ -223,14 +213,4 @@ namespace BizHawk.Client.EmuHawk
 			return samples * 1000.0 / SampleRate;
 		}
 	}
-
-	public interface ISoundOutput : IDisposable
-	{
-		void StartSound();
-		void StopSound();
-		void ApplyVolumeSettings(double volume);
-		int MaxSamplesDeficit { get; }
-		int CalculateSamplesNeeded();
-		void WriteSamples(short[] samples, int sampleCount);
-	}
 }

BizHawk.Client.EmuHawk/Sound/Utilities/SoundOutputProvider.cs

@@ -16,7 +16,7 @@ namespace BizHawk.Client.EmuHawk
 	// perform a "soft" correction by resampling it to hopefully get back inside our
 	// window shortly. If it ends up going too low or too high, we will perform a
 	// "hard" correction by generating silence or discarding samples.
-	public class SoundOutputProvider
+	public class SoundOutputProvider : IBufferedSoundProvider
 	{
 		private const int SampleRate = 44100;
 		private const int ChannelCount = 2;

BizHawk.Emulation.Common/BizHawk.Emulation.Common.csproj

@@ -117,6 +117,7 @@
     <Compile Include="EmulationExceptions.cs" />
     <Compile Include="Enums.cs" />
     <Compile Include="Extensions.cs" />
+    <Compile Include="Interfaces\IBufferedSoundProvider.cs" />
     <Compile Include="Interfaces\IController.cs" />
     <Compile Include="Interfaces\ICoreFileProvider.cs" />
     <Compile Include="Interfaces\IEmulator.cs" />

BizHawk.Emulation.Common/Interfaces/IBufferedSoundProvider.cs

@@ -0,0 +1,15 @@
+namespace BizHawk.Emulation.Common
+{
+	public interface IBufferedSoundProvider
+	{
+		/// <summary>
+		/// The source audio provider.
+		/// </summary>
+		ISoundProvider BaseSoundProvider { get; set; }
+
+		/// <summary>
+		/// Clears any internally buffered samples, and discards samples from the base provider (if set).
+		/// </summary>
+		void DiscardSamples();
+	}
+}

BizHawk.Emulation.Common/Sound/Utilities/BufferedAsync.cs

@@ -28,7 +28,7 @@ namespace BizHawk.Emulation.Common
 	 * TODO: For systems that _really_ don't need BufferedAsync (pce not turbocd, sms), make a way to signal
 	 *       that and then bypass the BufferedAsync.
 	 */
-	public sealed class BufferedAsync : ISoundProvider
+	public sealed class BufferedAsync : ISoundProvider, IBufferedSoundProvider
 	{
 		public ISoundProvider BaseSoundProvider { get; set; }