SoundOutputProvider: Standalone mode to eliminate the need for an external buffer when used with SyncToAsyncProvider.

BizHawk.Client.EmuHawk/MainForm.cs

@@ -3142,7 +3142,7 @@ namespace BizHawk.Client.EmuHawk
 				else
 				{
 					_currentSoundProvider.SetSyncMode(SyncSoundMode.Sync);
-					_aviSoundInputAsync = new SyncToAsyncProvider(_currentSoundProvider, 10.0);
+					_aviSoundInputAsync = new SyncToAsyncProvider(_currentSoundProvider);
 				}
 			}
 			_dumpProxy = new SimpleSyncSoundProvider();

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

@@ -32,6 +32,9 @@ namespace BizHawk.Client.EmuHawk
 		private const int MinResamplingDistanceSamples = 3;
 
 		private Queue<short> _buffer = new Queue<short>();
+		private bool _standaloneMode;
+		private int _targetExtraSamples;
+		private int _maxSamplesDeficit;
 
 		private Queue<int> _extraCountHistory = new Queue<int>();
 		private Queue<int> _outputCountHistory = new Queue<int>();
@@ -48,17 +51,37 @@ namespace BizHawk.Client.EmuHawk
 		private short[] _resampleBuffer = new short[0];
 		private double _resampleLengthRoundingError;
 
-		public SoundOutputProvider()
+		public SoundOutputProvider(bool standaloneMode = false)
 		{
+			_standaloneMode = standaloneMode;
+			if (_standaloneMode)
+			{
+				const double targetExtraMs = 10.0;
+				_targetExtraSamples = (int)Math.Ceiling(targetExtraMs * SampleRate / 1000.0);
+			}
+			ResetBuffer();
 		}
 
-		public int MaxSamplesDeficit { get; set; }
+		public int MaxSamplesDeficit
+		{
+			get { return _maxSamplesDeficit; }
+			set
+			{
+				if (_standaloneMode) throw new InvalidOperationException();
+				_maxSamplesDeficit = value;
+			}
+		}
+
+		private int EffectiveMaxSamplesDeficit
+		{
+			get { return _maxSamplesDeficit + _targetExtraSamples; }
+		}
 
 		public ISoundProvider BaseSoundProvider { get; set; }
 
 		public void DiscardSamples()
 		{
-			_buffer.Clear();
+			ResetBuffer();
 			_extraCountHistory.Clear();
 			_outputCountHistory.Clear();
 			_hardCorrectionHistory.Clear();
@@ -76,6 +99,15 @@ namespace BizHawk.Client.EmuHawk
 			}
 		}
 
+		private void ResetBuffer()
+		{
+			_buffer.Clear();
+			for (int i = 0; i < _targetExtraSamples * ChannelCount; i++)
+			{
+				_buffer.Enqueue(0);
+			}
+		}
+
 		// To let us know about buffer underruns, rewinding, fast-forwarding, etc.
 		public void OnVolatility()
 		{
@@ -91,7 +123,23 @@ namespace BizHawk.Client.EmuHawk
 			get { return SampleRate / Global.Emulator.CoreComm.VsyncRate; }
 		}
 
+		public void GetSamples(short[] samples)
+		{
+			if (!_standaloneMode) throw new InvalidOperationException();
+			int returnSampleCount = samples.Length / ChannelCount;
+			GetSamples(returnSampleCount);
+			GetSamplesFromBuffer(samples, returnSampleCount);
+		}
+
 		public void GetSamples(int idealSampleCount, out short[] samples, out int sampleCount)
+		{
+			if (_standaloneMode) throw new InvalidOperationException();
+			sampleCount = GetSamples(idealSampleCount);
+			samples = GetOutputBuffer(sampleCount);
+			GetSamplesFromBuffer(samples, sampleCount);
+		}
+
+		private int GetSamples(int idealSampleCount)
 		{
 			double scaleFactor = 1.0;
 
@@ -108,9 +156,9 @@ namespace BizHawk.Client.EmuHawk
 			GetSamplesFromBase(ref scaleFactor);
 
 			int bufferSampleCount = _buffer.Count / ChannelCount;
-			int extraSampleCount = bufferSampleCount - idealSampleCount;
+			int extraSampleCount = bufferSampleCount - _targetExtraSamples - idealSampleCount;
 			int maxSamplesDeficit = _extraCountHistory.Count >= UsableHistoryLength ?
-				MaxSamplesDeficit : Math.Min(StartupMaxSamplesSurplusDeficit, MaxSamplesDeficit);
+				EffectiveMaxSamplesDeficit : Math.Min(StartupMaxSamplesSurplusDeficit, EffectiveMaxSamplesDeficit);
 			int maxSamplesSurplus = _extraCountHistory.Count >= UsableHistoryLength ?
 				MaxSamplesSurplus : Math.Min(StartupMaxSamplesSurplusDeficit, MaxSamplesSurplus);
 			bool hardCorrected = false;
@@ -137,7 +185,7 @@ namespace BizHawk.Client.EmuHawk
 			}
 
 			bufferSampleCount = _buffer.Count / ChannelCount;
-			extraSampleCount = bufferSampleCount - idealSampleCount;
+			extraSampleCount = bufferSampleCount - _targetExtraSamples - idealSampleCount;
 
 			int outputSampleCount = Math.Min(idealSampleCount, bufferSampleCount);
 
@@ -154,9 +202,7 @@ namespace BizHawk.Client.EmuHawk
 					scaleFactor);
 			}
 
-			sampleCount = outputSampleCount;
+			return outputSampleCount;
-			samples = GetOutputBuffer(sampleCount);
-			GetSamplesFromBuffer(samples, sampleCount);
 		}
 
 		private void GetSamplesFromBase(ref double scaleFactor)

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

@@ -1,5 +1,4 @@
 using System;
-using System.Collections.Generic;
 
 using BizHawk.Emulation.Common;
 
@@ -7,41 +6,16 @@ namespace BizHawk.Client.EmuHawk
 {
 	public class SyncToAsyncProvider : ISoundProvider
 	{
-		private const int SampleRate = 44100;
+		private readonly SoundOutputProvider _outputProvider = new SoundOutputProvider(standaloneMode: true);
-		private const int ChannelCount = 2;
-		private const double MinExpectedFrameRate = 50;
 
-		private readonly SoundOutputProvider _outputProvider = new SoundOutputProvider();
+		public SyncToAsyncProvider(ISoundProvider baseProvider)
-		private readonly int _bufferSizeSamples;
-		private readonly Queue<short> _buffer;
-
-		public SyncToAsyncProvider(ISoundProvider baseProvider, double bufferSizeMs)
 		{
 			_outputProvider.BaseSoundProvider = baseProvider;
-			_bufferSizeSamples = (int)Math.Ceiling(bufferSizeMs * SampleRate / 1000.0);
-			_buffer = new Queue<short>((_bufferSizeSamples + (int)Math.Ceiling(SampleRate / MinExpectedFrameRate)) * ChannelCount);
-
-			DiscardSamples();
 		}
 
 		public void DiscardSamples()
 		{
-			_buffer.Clear();
 			_outputProvider.DiscardSamples();
-
-			for (int i = 0; i < _bufferSizeSamples * ChannelCount; i++)
-			{
-				_buffer.Enqueue(0);
-			}
-		}
-
-		public void GetSamplesAsync(short[] samples)
-		{
-			GetSamplesFromBase(samples.Length / ChannelCount);
-			for (int i = 0; i < samples.Length; i++)
-			{
-				samples[i] = _buffer.Dequeue();
-			}
 		}
 
 		public bool CanProvideAsync
@@ -67,17 +41,9 @@ namespace BizHawk.Client.EmuHawk
 			throw new InvalidOperationException("Sync mode is not supported.");
 		}
 
-		private void GetSamplesFromBase(int minResultingSampleCount)
+		public void GetSamplesAsync(short[] samples)
 		{
-			int idealSampleCount = Math.Max(_bufferSizeSamples + minResultingSampleCount - (_buffer.Count / ChannelCount), 0);
+			_outputProvider.GetSamples(samples);
-			short[] samples;
-			int samplesProvided;
-			_outputProvider.MaxSamplesDeficit = _bufferSizeSamples;
-			_outputProvider.GetSamples(idealSampleCount, out samples, out samplesProvided);
-			for (int i = 0; i < samplesProvided * ChannelCount; i++)
-			{
-				_buffer.Enqueue(samples[i]);
-			}
 		}
 	}
 }