sound api changes. added a new ISyncSoundProvider, which works similarly to ISoundProvider except the source (not the sink) determines the number of samples to process. Added facilities to metaspu, dcfilter, speexresampler to work with ISyncSoundProvider. Add ISyncSoundProvider to IEmulator. All IEmulators must provide sync sound, but they need not provide async sound. When async is needed and an IEmulator doesn't provide it, the frontend will wrap it in a vecna metaspu. SNES, GB changed to provide sync sound only. All other emulator cores mostly unchanged; they just provide stub fakesync alongside async, for now. For the moment, the only use of the sync sound is for realtime audio throttling, where it works and sounds quite nice. In the future, sync sound will be supported for AV dumping as well.

BizHawk.Emulation/BizHawk.Emulation.csproj

@@ -353,6 +353,7 @@
     <Compile Include="Interfaces\Base Implementations\NullController.cs" />
     <Compile Include="Interfaces\Base Implementations\NullEmulator.cs" />
     <Compile Include="Interfaces\CoreComms.cs" />
+    <Compile Include="Interfaces\ISyncSoundProvider.cs" />
     <Compile Include="Properties\svnrev.cs" />
     <Compile Include="QuickCollections.cs" />
     <Compile Include="Sound\CDAudio.cs" />

BizHawk.Emulation/Consoles/Atari/2600/Atari2600.cs

@@ -13,6 +13,9 @@ namespace BizHawk
 		public CoreOutputComm CoreOutputComm { get; private set; }
 		public IVideoProvider VideoProvider { get { return tia; } }
 		public ISoundProvider SoundProvider { get { return dcfilter; } }
+		public ISyncSoundProvider SyncSoundProvider { get { return new FakeSyncSound(dcfilter, 735); } }
+		public bool StartAsyncSound() { return true; }
+		public void EndAsyncSound() { }
 
 		public Atari2600(GameInfo game, byte[] rom)
 		{

BizHawk.Emulation/Consoles/Calculator/TI83.cs

@@ -393,6 +393,9 @@ namespace BizHawk.Emulation.Consoles.Calculator
 			get { return new MyVideoProvider(this); } }
 
 		public ISoundProvider SoundProvider { get { return NullSound.SilenceProvider; } }
+		public ISyncSoundProvider SyncSoundProvider { get { return new FakeSyncSound(NullSound.SilenceProvider, 735); } }
+		public bool StartAsyncSound() { return true; }
+		public void EndAsyncSound() { }
 
 		public static readonly ControllerDefinition TI83Controller =
 			new ControllerDefinition

BizHawk.Emulation/Consoles/Coleco/ColecoVision.cs

@@ -18,6 +18,9 @@ namespace BizHawk.Emulation.Consoles.Coleco
 		public CoreOutputComm CoreOutputComm { get; private set; }
 		public IVideoProvider VideoProvider { get { return this; } }
 		public ISoundProvider SoundProvider { get { return this; } }
+		public ISyncSoundProvider SyncSoundProvider { get { return new FakeSyncSound(this, 735); } }
+		public bool StartAsyncSound() { return true; }
+		public void EndAsyncSound() { }
 		public byte[] ram = new byte[2048];
 
 		public DisplayType DisplayType { get; set; } //TOOD: delete me

BizHawk.Emulation/Consoles/Intellivision/Intellivision.cs

@@ -85,6 +85,9 @@ namespace BizHawk.Emulation.Consoles.Intellivision
 
 		public IVideoProvider VideoProvider { get { return Stic; } }
 		public ISoundProvider SoundProvider { get { return NullSound.SilenceProvider; } }
+		public ISyncSoundProvider SyncSoundProvider { get { return new FakeSyncSound(NullSound.SilenceProvider, 735); } }
+		public bool StartAsyncSound() { return true; }
+		public void EndAsyncSound() { }
 
 		public static readonly ControllerDefinition IntellivisionController =
 			new ControllerDefinition

BizHawk.Emulation/Consoles/Nintendo/Gameboy/Gambatte.cs

@@ -9,7 +9,7 @@ namespace BizHawk.Emulation.Consoles.GB
 	/// <summary>
 	/// a gameboy/gameboy color emulator wrapped around native C++ libgambatte
 	/// </summary>
-	public class Gameboy : IEmulator, IVideoProvider, ISoundProvider
+	public class Gameboy : IEmulator, IVideoProvider, ISyncSoundProvider
 	{
 		/// <summary>
 		/// internal gambatte state
@@ -572,8 +572,11 @@ namespace BizHawk.Emulation.Consoles.GB
 
 		public ISoundProvider SoundProvider
 		{
-			get { return this; }
+			get { return null; }
 		}
+		public ISyncSoundProvider SyncSoundProvider { get { return dcfilter; } }
+		public bool StartAsyncSound() { return false; }
+		public void EndAsyncSound() { }
 
 		/// <summary>
 		/// sample pairs before resampling
@@ -585,15 +588,12 @@ namespace BizHawk.Emulation.Consoles.GB
 		int soundbuffcontains = 0;
 
 		Sound.Utilities.SpeexResampler resampler;
-		Sound.MetaspuSoundProvider metaspu;
-
 		Sound.Utilities.DCFilter dcfilter;
 
 		void InitSound()
 		{
-			dcfilter = new Sound.Utilities.DCFilter();
+			resampler = new Sound.Utilities.SpeexResampler(2, 2097152, 44100, 2097152, 44100, null, this);
-			metaspu = new Sound.MetaspuSoundProvider(Sound.ESynchMethod.ESynchMethod_V);
+			dcfilter = new Sound.Utilities.DCFilter(resampler, 65536);
-			resampler = new Sound.Utilities.SpeexResampler(2, 2097152, 44100, 2097152, 44100, LoadThroughSamples);
 		}
 
 		void DisposeSound()
@@ -602,29 +602,16 @@ namespace BizHawk.Emulation.Consoles.GB
 			resampler = null;
 		}
 
-		void LoadThroughSamples(short[] buff, int length)
-		{
-			dcfilter.PushThroughSamples(buff, length * 2);
-			metaspu.buffer.enqueue_samples(buff, length);
-		}
-
-		public void GetSamples(short[] samples)
-		{
-			if (soundbuffcontains > 0)
-			{
-				resampler.EnqueueSamples(soundbuff, soundbuffcontains);
-				soundbuffcontains = 0;
-				resampler.Flush();
-				metaspu.GetSamples(samples);
-			}
-		}
-
 		public void DiscardSamples()
 		{
-			metaspu.DiscardSamples();
+			soundbuffcontains = 0;
 		}
 
-		public int MaxVolume { get; set; }
+		public void GetSamples(out short[] samples, out int nsamp)
+		{
+			samples = soundbuff;
+			nsamp = soundbuffcontains;
+		}
 		#endregion
 
 	}

BizHawk.Emulation/Consoles/Nintendo/NES/NES.cs

@@ -207,6 +207,9 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 		MyVideoProvider videoProvider;
 		public IVideoProvider VideoProvider { get { return videoProvider; } }
 		public ISoundProvider SoundProvider { get { return magicSoundProvider; } }
+		public ISyncSoundProvider SyncSoundProvider { get { return new FakeSyncSound(magicSoundProvider, 734); } }
+		public bool StartAsyncSound() { return true; }
+		public void EndAsyncSound() { }
 
 		public static readonly ControllerDefinition NESController =
 			new ControllerDefinition

BizHawk.Emulation/Consoles/Nintendo/SNES/LibsnesCore.cs

@@ -282,7 +282,7 @@ namespace BizHawk.Emulation.Consoles.Nintendo.SNES
 		}
 	}
 
-	public unsafe class LibsnesCore : IEmulator, IVideoProvider, ISoundProvider
+	public unsafe class LibsnesCore : IEmulator, IVideoProvider
 	{
 		public bool IsSGB { get; private set; }
 
@@ -643,7 +643,6 @@ namespace BizHawk.Emulation.Consoles.Nintendo.SNES
 		int vidWidth = 256, vidHeight = 224;
 
 		public IVideoProvider VideoProvider { get { return this; } }
-		public ISoundProvider SoundProvider { get { return this; } }
 
 		public ControllerDefinition ControllerDefinition { get { return SNESController; } }
 		IController controller;
@@ -992,39 +991,23 @@ namespace BizHawk.Emulation.Consoles.Nintendo.SNES
 
 		#region audio stuff
 
-		void InitAudio()
-		{
-			metaspu = new Sound.MetaspuSoundProvider(Sound.ESynchMethod.ESynchMethod_V);
-			resampler = new Sound.Utilities.SpeexResampler(6, 64081, 88200, 32041, 44100, new Action<short[], int>(metaspu.buffer.enqueue_samples));
-
-		}
-
 		Sound.Utilities.SpeexResampler resampler;
 
-		Sound.MetaspuSoundProvider metaspu;
+		void InitAudio()
+		{
+			resampler = new Sound.Utilities.SpeexResampler(6, 64081, 88200, 32041, 44100);
+		}
 
 		void snes_audio_sample(ushort left, ushort right)
 		{
 			resampler.EnqueueSample((short)left, (short)right);
 		}
 
-
+		public ISoundProvider SoundProvider { get { return null; } }
-		//BinaryWriter dbgs = new BinaryWriter(File.Open("dbgwav.raw", FileMode.Create, FileAccess.Write));
+		public ISyncSoundProvider SyncSoundProvider { get { return resampler; } }
-
+		public bool StartAsyncSound() { return false; }
-		public void GetSamples(short[] samples)
+		public void EndAsyncSound() { }
-		{
-			resampler.Flush();
-			metaspu.GetSamples(samples);
-		}
-
-		public void DiscardSamples()
-		{
-			metaspu.DiscardSamples();
-		}
-
-		public int MaxVolume { get; set; }
 
 		#endregion audio stuff
-
 	}
 }

BizHawk.Emulation/Consoles/PC Engine/PCEngine.cs

@@ -277,6 +277,9 @@ namespace BizHawk.Emulation.Consoles.TurboGrafx
 		{
 			get { return soundProvider; }
 		}
+		public ISyncSoundProvider SyncSoundProvider { get { return new FakeSyncSound(soundProvider, 735); } }
+		public bool StartAsyncSound() { return true; }
+		public void EndAsyncSound() { }
 
 		public string SystemId { get { return systemid; } }
 		public string Region { get; set; }

BizHawk.Emulation/Consoles/Sega/Genesis/Genesis.cs

@@ -260,6 +260,9 @@ namespace BizHawk.Emulation.Consoles.Sega
 		{
 			get { return SoundMixer; }
 		}
+		public ISyncSoundProvider SyncSoundProvider { get { return new FakeSyncSound(SoundMixer, 735); } }
+		public bool StartAsyncSound() { return true; }
+		public void EndAsyncSound() { }
 
 		public int Frame { get; set; }
 		public int LagCount { get { return _lagcount; } set { _lagcount = value; } }

BizHawk.Emulation/Consoles/Sega/SMS/SMS.cs

@@ -353,6 +353,9 @@ namespace BizHawk.Emulation.Consoles.Sega
 
 		ISoundProvider ActiveSoundProvider;
 		public ISoundProvider SoundProvider { get { return ActiveSoundProvider; } }
+		public ISyncSoundProvider SyncSoundProvider { get { return new FakeSyncSound(ActiveSoundProvider, 735); } }
+		public bool StartAsyncSound() { return true; }
+		public void EndAsyncSound() { }
 
 		public string SystemId { get { return "SMS"; } }
 

BizHawk.Emulation/Interfaces/Base Implementations/NullEmulator.cs

@@ -15,6 +15,10 @@ namespace BizHawk
 		public CoreOutputComm CoreOutputComm { get; private set; }
 		public IVideoProvider VideoProvider { get { return this; } }
 		public ISoundProvider SoundProvider { get { return this; } }
+		public ISyncSoundProvider SyncSoundProvider { get { return new FakeSyncSound(this, 735); } }
+		public bool StartAsyncSound() { return true; }
+		public void EndAsyncSound() { }
+		
 		public NullEmulator()
 		{
 			var domains = new List<MemoryDomain>(1);

BizHawk.Emulation/Interfaces/IEmulator.cs

@@ -8,6 +8,11 @@ namespace BizHawk
 	{
 		IVideoProvider VideoProvider { get; }
 		ISoundProvider SoundProvider { get; }
+		ISyncSoundProvider SyncSoundProvider { get; }
+		/// <summary></summary>
+		/// <returns>false if core doesn't support async sound</returns>
+		bool StartAsyncSound();
+		void EndAsyncSound();
 
 		ControllerDefinition ControllerDefinition { get; }
 		IController Controller { get; set; }

BizHawk.Emulation/Interfaces/ISyncSoundProvider.cs

@@ -0,0 +1,45 @@
+namespace BizHawk
+{
+	public interface ISyncSoundProvider
+	{
+		/// <summary>
+		/// 
+		/// </summary>
+		/// <param name="samples"></param>
+		/// <param name="nsamp">number of sample PAIRS available</param>
+		void GetSamples(out short[] samples, out int nsamp);
+		/// <summary>
+		/// 
+		/// </summary>
+		void DiscardSamples();
+	}
+
+	public class FakeSyncSound : ISyncSoundProvider
+	{
+		ISoundProvider source;
+		int spf;
+		/// <summary>
+		/// 
+		/// </summary>
+		/// <param name="source"></param>
+		/// <param name="spf">number of sample pairs to request for each call</param>
+		public FakeSyncSound(ISoundProvider source, int spf)
+		{
+			this.source = source;
+			this.spf = spf;
+		}
+
+		public void GetSamples(out short[] samples, out int nsamp)
+		{
+			short[] ret = new short[spf * 2];
+			source.GetSamples(ret);
+			samples = ret;
+			nsamp = spf;
+		}
+
+		public void DiscardSamples()
+		{
+			source.DiscardSamples();
+		}
+	}
+}

BizHawk.Emulation/Sound/Utilities/DCFilter.cs

@@ -8,7 +8,7 @@ namespace BizHawk.Emulation.Sound.Utilities
 	/// <summary>
 	/// implements a DC block filter on top of an ISoundProvider.  rather simple.
 	/// </summary>
-	public class DCFilter : ISoundProvider
+	public class DCFilter : ISoundProvider, ISyncSoundProvider
 	{
 		/*
 		 * A note about accuracy:
@@ -18,6 +18,7 @@ namespace BizHawk.Emulation.Sound.Utilities
 		 */
 
 		ISoundProvider input;
+		ISyncSoundProvider syncinput;
 
 		int sumL = 0;
 		int sumR = 0;
@@ -35,35 +36,41 @@ namespace BizHawk.Emulation.Sound.Utilities
 			if (filterwidth < 1 || filterwidth > 65536)
 				throw new ArgumentOutOfRangeException();
 			this.input = input;
+			this.syncinput = null;
+			this.depth = filterwidth;
+			this.buffer = new Queue<short>(depth * 2);
+			for (int i = 0; i < depth * 2; i++)
+				buffer.Enqueue(0);			
+		}
+
+		public DCFilter(ISyncSoundProvider input, int filterwidth)
+		{
+			if (filterwidth < 1 || filterwidth > 65536)
+				throw new ArgumentOutOfRangeException();
+			this.input = null;
+			this.syncinput = input;
 			this.depth = filterwidth;
 			this.buffer = new Queue<short>(depth * 2);
 			for (int i = 0; i < depth * 2; i++)
 				buffer.Enqueue(0);
 		}
-
-		/// <summary>
-		/// returns the original sound provider (in case you lost it).
-		/// after calling, the DCFilter is no longer valid
-		/// </summary>
-		/// <returns></returns>
-		public ISoundProvider Detatch()
-		{
-			var ret = input;
-			input = null;
-			return ret;
-		}
 		
 		/// <summary>
-		/// pass a set of samples through the filter.  should not be mixed with pull (ISoundProvider) mode
+		/// pass a set of samples through the filter.  should not be mixed with pull (ISoundProvider) mode or sync mode
 		/// </summary>
 		public void PushThroughSamples(short[] samples, int length)
+		{
+			PushThroughSamples(samples, samples, length);
+		}
+
+		void PushThroughSamples(short[] samplesin, short[] samplesout, int length)
 		{
 			for (int i = 0; i < length; i += 2)
 			{
 				sumL -= buffer.Dequeue();
 				sumR -= buffer.Dequeue();
-				short L = samples[i];
+				short L = samplesin[i];
-				short R = samples[i + 1];
+				short R = samplesin[i + 1];
 				sumL += L;
 				sumR += R;
 				buffer.Enqueue(L);
@@ -72,19 +79,19 @@ namespace BizHawk.Emulation.Sound.Utilities
 				int bigR = R - sumR / depth;
 				// check for clipping
 				if (bigL > 32767)
-					samples[i] = 32767;
+					samplesout[i] = 32767;
 				else if (bigL < -32768)
-					samples[i] = -32768;
+					samplesout[i] = -32768;
 				else
-					samples[i] = (short)bigL;
+					samplesout[i] = (short)bigL;
 				if (bigR > 32767)
-					samples[i + 1] = 32767;
+					samplesout[i + 1] = 32767;
 				else if (bigR < -32768)
-					samples[i + 1] = -32768;
+					samplesout[i + 1] = -32768;
 				else
-					samples[i + 1] = (short)bigR;
+					samplesout[i + 1] = (short)bigR;
-
 			}
+
 		}
 
 		public void GetSamples(short[] samples)
@@ -95,7 +102,10 @@ namespace BizHawk.Emulation.Sound.Utilities
 
 		public void DiscardSamples()
 		{
-			input.DiscardSamples();
+			if (input != null)
+				input.DiscardSamples();
+			if (syncinput != null)
+				syncinput.DiscardSamples();
 		}
 
 		public int MaxVolume
@@ -109,5 +119,16 @@ namespace BizHawk.Emulation.Sound.Utilities
 				input.MaxVolume = value;
 			}
 		}
+
+		public void GetSamples(out short[] samples, out int nsamp)
+		{
+			short[] sampin;
+			int nsampin;
+			syncinput.GetSamples(out sampin, out nsampin);
+			short[] ret = new short[nsampin * 2];
+			PushThroughSamples(sampin, ret, nsampin * 2);
+			samples = ret;
+			nsamp = nsampin;
+		}
 	}
 }

BizHawk.Emulation/Sound/Utilities/Metaspu.cs

@@ -3,6 +3,39 @@ using System.Collections.Generic;
 
 namespace BizHawk.Emulation.Sound
 {
+	/// <summary>
+	/// uses Metaspu to have an ISyncSoundProvider input to a ISoundProvider
+	/// </summary>
+	public class MetaspuAsync : ISoundProvider
+	{
+		ISynchronizingAudioBuffer buffer;
+		ISyncSoundProvider input;
+		public MetaspuAsync(ISyncSoundProvider input, ESynchMethod method)
+		{
+			buffer = Metaspu.metaspu_construct(method);
+			this.input = input;
+		}
+
+		public void GetSamples(short[] samples)
+		{
+			short[] sampin;
+			int numsamp;
+			input.GetSamples(out sampin, out numsamp);
+			buffer.enqueue_samples(sampin, numsamp);
+			buffer.output_samples(samples, samples.Length / 2);
+		}
+
+		public void DiscardSamples()
+		{
+			input.DiscardSamples();
+			buffer.clear();
+		}
+
+		public int MaxVolume { get; set; }
+	}
+
+
+
 	public class MetaspuSoundProvider : ISoundProvider
 	{
 		public ISynchronizingAudioBuffer buffer;

BizHawk.Emulation/Sound/Utilities/SpeexResampler.cs

@@ -9,7 +9,7 @@ namespace BizHawk.Emulation.Sound.Utilities
 	/// <summary>
 	/// junk wrapper around LibSpeexDSP.  quite inefficient.  will be replaced
 	/// </summary>
-	public class SpeexResampler : IDisposable
+	public class SpeexResampler : IDisposable, ISyncSoundProvider
 	{
 		static class LibSpeexDSP
 		{
@@ -269,6 +269,13 @@ namespace BizHawk.Emulation.Sound.Utilities
 
 		short[] outbuf;
 
+		// for ISyncSoundProvider
+		short[] outbuf2 = new short[16];
+		int outbuf2pos = 0;
+
+		// to accept an ISyncSoundProvder input
+		ISyncSoundProvider input;
+
 		/// <summary>
 		/// in buffer position in samples (not sample pairs)
 		/// </summary>
@@ -303,8 +310,9 @@ namespace BizHawk.Emulation.Sound.Utilities
 		/// <param name="ratioden">demonenator of srate change ratio (inrate / outrate)</param>
 		/// <param name="sratein">sampling rate in, rounded to nearest hz</param>
 		/// <param name="srateout">sampling rate out, rounded to nearest hz</param>
-		/// <param name="drainer">function which accepts output as produced</param>
+		/// <param name="drainer">function which accepts output as produced. if null, act as an ISyncSoundProvider</param>
-		public SpeexResampler(int quality, uint rationum, uint ratioden, uint sratein, uint srateout, Action<short[], int> drainer)
+		/// <param name="input">source to take input from when output is requested. if null, no autofetching</param>
+		public SpeexResampler(int quality, uint rationum, uint ratioden, uint sratein, uint srateout, Action<short[], int> drainer = null, ISyncSoundProvider input = null)
 		{
 			LibSpeexDSP.RESAMPLER_ERR err = LibSpeexDSP.RESAMPLER_ERR.SUCCESS;
 			st = LibSpeexDSP.speex_resampler_init_frac(2, rationum, ratioden, sratein, srateout, quality, ref err);
@@ -314,13 +322,16 @@ namespace BizHawk.Emulation.Sound.Utilities
 
 			CheckError(err);
 
-			//System.Windows.Forms.MessageBox.Show(string.Format("inlat: {0} outlat: {1}", LibSpeexDSP.speex_resampler_get_input_latency(st), LibSpeexDSP.speex_resampler_get_output_latency(st)));
+			if (drainer != null && input != null)
-			this.drainer = drainer;
+				throw new ArgumentException("Can't autofetch without being an ISyncSoundProvider?");
+
+			if (drainer != null)
+				this.drainer = drainer;
+			else
+				this.drainer = InternalDrain;
+			this.input = input;
 
 			outbuf = new short[inbuf.Length * ratioden / rationum / 2 * 2 + 128];
-
-			//System.Windows.Forms.MessageBox.Show(string.Format("inbuf: {0} outbuf: {1}", inbuf.Length, outbuf.Length));
-
 		}
 
 		/// <summary>
@@ -372,62 +383,54 @@ namespace BizHawk.Emulation.Sound.Utilities
 
 			// reset inbuf
 
-			Buffer.BlockCopy(inbuf, (int)inal * 2 * sizeof(short), inbuf, 0, inbufpos - (int)inal * 2);
+			if (inal != inbufpos / 2)
-			inbufpos -= (int)inal * 2;
+				throw new Exception("Speexresampler didn't eat the whole array?");
+			inbufpos = 0;
+
+			//Buffer.BlockCopy(inbuf, (int)inal * 2 * sizeof(short), inbuf, 0, inbufpos - (int)inal * 2);
+			//inbufpos -= (int)inal * 2;
 
 			// dispatch outbuf
 			drainer(outbuf, (int)outal);
 		}
 
-
-		/*
-		public void ResampleChunk(Queue<short> input, Queue<short> output, bool finish)
-		{
-			while (input.Count > 0)
-			{
-				short[] ina = input.ToArray();
-
-				short[] outa = new short[8192];
-
-				uint inal = (uint)ina.Length / 2;
-				uint outal = (uint)outa.Length / 2;
-
-				// very important: feeding too big a buffer at once causes garbage to come back
-				// don't know what "too big a buffer" is in general
-				if (inal > 512) inal = 512;
-
-
-				LibSpeexDSP.speex_resampler_process_interleaved_int(st, ina, ref inal, outa, ref outal);
-
-
-				while (inal > 0)
-				{
-					input.Dequeue();
-					input.Dequeue();
-					inal--;
-				}
-
-				int i = 0;
-				if (outal == 0)
-				{
-					// resampler refuses to make more data; bail
-					return;
-				}
-				while (outal > 0)
-				{
-					output.Enqueue(outa[i++]);
-					output.Enqueue(outa[i++]);
-					outal--;
-				}
-			}
-		}
-		*/
-
 		public void Dispose()
 		{
 			LibSpeexDSP.speex_resampler_destroy(st);
 			st = IntPtr.Zero;
 		}
+
+		void InternalDrain(short[] buf, int nsamp)
+		{
+			if (outbuf2pos + nsamp * 2 > outbuf2.Length)
+			{
+				short[] newbuf = new short[outbuf2pos + nsamp * 2];
+				Buffer.BlockCopy(outbuf2, 0, newbuf, 0, outbuf2pos * sizeof(short));
+				outbuf2 = newbuf;
+			}
+			Buffer.BlockCopy(buf, 0, outbuf2, outbuf2pos * sizeof(short), nsamp * 2 * sizeof(short));
+			outbuf2pos += nsamp * 2;
+		}
+
+		public void GetSamples(out short[] samples, out int nsamp)
+		{
+			if (input != null)
+			{
+				short[] sampin;
+				int nsampin;
+				input.GetSamples(out sampin, out nsampin);
+				EnqueueSamples(sampin, nsampin);
+			}
+			Flush();
+			nsamp = outbuf2pos / 2;
+			samples = outbuf2;
+			outbuf2pos = 0;
+		}
+
+		public void DiscardSamples()
+		{
+			outbuf2pos = 0;
+		}
 	}
 }
 

BizHawk.MultiClient/MainForm.MenuItems.cs

@@ -140,7 +140,9 @@ namespace BizHawk.MultiClient
 		private void soundToolStripMenuItem_Click(object sender, EventArgs e)
 		{
 			SoundConfig s = new SoundConfig();
-			s.ShowDialog();
+			var result = s.ShowDialog();
+			if (result == System.Windows.Forms.DialogResult.OK)
+				RewireSound();
 		}
 
 		private void zoomMenuItem_Click(object sender, EventArgs e)

BizHawk.MultiClient/MainForm.cs

@@ -40,6 +40,7 @@ namespace BizHawk.MultiClient
 		public bool NeedsReboot = false;
 		//avi/wav state
 		IVideoWriter CurrAviWriter = null;
+		ISoundProvider AviSoundInput = null;
 		/// <summary>
 		/// an audio proxy used for dumping
 		/// </summary>
@@ -1645,10 +1646,41 @@ namespace BizHawk.MultiClient
 				Global.StickyXORAdapter.ClearStickies();
 				Global.AutofireStickyXORAdapter.ClearStickies();
 
+				RewireSound();
+
 				return true;
 			}
 		}
 
+		void RewireSound()
+		{
+			if (DumpProxy != null)
+			{
+				// we're video dumping, so async mode only and use the DumpProxy.
+				// note that the avi dumper has already rewired the emulator itself in this case.
+				Global.Sound.SetAsyncInputPin(DumpProxy);
+			}
+			else if (Global.Config.SoundThrottle)
+			{
+				// for sound throttle, use sync mode
+				Global.Emulator.EndAsyncSound();
+				Global.Sound.SetSyncInputPin(Global.Emulator.SyncSoundProvider);
+			}
+			else
+			{
+				// for vsync\clock throttle modes, use async
+				if (!Global.Emulator.StartAsyncSound())
+				{
+					// if the core doesn't support async mode, use a standard vecna wrapper
+					Global.Sound.SetAsyncInputPin(new Emulation.Sound.MetaspuAsync(Global.Emulator.SyncSoundProvider, Emulation.Sound.ESynchMethod.ESynchMethod_V));
+				}
+				else
+				{
+					Global.Sound.SetAsyncInputPin(Global.Emulator.SoundProvider);
+				}
+			}
+		}
+
 		private void UpdateDumpIcon()
 		{
 			DumpStatus.Image = BizHawk.MultiClient.Properties.Resources.Blank;
@@ -2259,10 +2291,8 @@ namespace BizHawk.MultiClient
 					SoundRemainder = nsampnum % Global.Emulator.CoreOutputComm.VsyncNum;
 
 					short[] temp = new short[nsamp * 2];
-					Global.Emulator.SoundProvider.GetSamples(temp);
+					AviSoundInput.GetSamples(temp);
 					DumpProxy.buffer.enqueue_samples(temp, (int)nsamp);
-					//DumpProxy.GetSamples(temp);
-					//genSound = false;
 
 					if (Global.Config.AVI_CaptureOSD)
 					{
@@ -2314,14 +2344,10 @@ namespace BizHawk.MultiClient
 
 			if (genSound)
 			{
-				// change audio path if dumping is occuring
+				Global.Sound.UpdateSound();
-				if (DumpProxy != null)
-					Global.Sound.UpdateSound(DumpProxy);
-				else
-					Global.Sound.UpdateSound(Global.Emulator.SoundProvider);
 			}
 			else
-				Global.Sound.UpdateSound(NullSound.SilenceProvider);
+				Global.Sound.UpdateSilence();
 		}
 
 		
@@ -3377,6 +3403,7 @@ namespace BizHawk.MultiClient
 				AVIStatusLabel.Image = BizHawk.MultiClient.Properties.Resources.AVI;
 				AVIStatusLabel.ToolTipText = "A/V capture in progress";
 				AVIStatusLabel.Visible = true;
+				
 			}
 			catch
 			{
@@ -3385,9 +3412,14 @@ namespace BizHawk.MultiClient
 				throw;
 			}
 
-			// buffersize here is entirely guess
+			// do sound rewire.  the plan is to eventually have AVI writing support syncsound input, but it doesn't for the moment
+			if (!Global.Emulator.StartAsyncSound())
+				AviSoundInput = new Emulation.Sound.MetaspuAsync(Global.Emulator.SyncSoundProvider, Emulation.Sound.ESynchMethod.ESynchMethod_V);
+			else
+				AviSoundInput = Global.Emulator.SoundProvider;
 			DumpProxy = new Emulation.Sound.MetaspuSoundProvider(Emulation.Sound.ESynchMethod.ESynchMethod_V);
 			SoundRemainder = 0;
+			RewireSound();
 		}
 
 		public void StopAVI()
@@ -3395,6 +3427,7 @@ namespace BizHawk.MultiClient
 			if (CurrAviWriter == null)
 			{
 				DumpProxy = null;
+				RewireSound();
 				return;
 			}
 			CurrAviWriter.CloseFile();
@@ -3404,8 +3437,10 @@ namespace BizHawk.MultiClient
 			AVIStatusLabel.Image = BizHawk.MultiClient.Properties.Resources.Blank;
 			AVIStatusLabel.ToolTipText = "";
 			AVIStatusLabel.Visible = false;
+			AviSoundInput = null;
 			DumpProxy = null; // return to normal sound output
 			SoundRemainder = 0;
+			RewireSound();
 		}
 
 		private void SwapBackupSavestate(string path)

BizHawk.MultiClient/Sound.cs

@@ -12,7 +12,7 @@ namespace BizHawk.MultiClient
 #if WINDOWS
 	public class Sound : IDisposable
 	{
-		public bool Muted = false;
+		private bool Muted = false;
 		private bool disposed = false;
 
 		private SecondarySoundBuffer DSoundBuffer;
@@ -23,6 +23,9 @@ namespace BizHawk.MultiClient
 
 		private BufferedAsync semisync = new BufferedAsync();
 
+		private ISoundProvider asyncsoundProvider;
+		private ISyncSoundProvider syncsoundProvider;
+
 		public Sound(IntPtr handle, DirectSound device)
 		{
 			if (device != null)
@@ -94,6 +97,20 @@ namespace BizHawk.MultiClient
 			}
 		}
 
+		public void SetSyncInputPin(ISyncSoundProvider source)
+		{
+			syncsoundProvider = source;
+			asyncsoundProvider = null;
+			semisync.DiscardSamples();
+		}
+
+		public void SetAsyncInputPin(ISoundProvider source)
+		{
+			syncsoundProvider = null;
+			asyncsoundProvider = source;
+			semisync.BaseSoundProvider = source;
+		}
+
 		static int circularDist(int from, int to, int size)
 		{
 			if (size == 0)
@@ -121,53 +138,68 @@ namespace BizHawk.MultiClient
 			return curToPlay / 4;
 		}
 
-		public void UpdateSound(ISoundProvider soundProvider)
+		public void UpdateSilence()
+		{
+			Muted = true;
+			UpdateSound();
+			Muted = false;
+		}
+
+		public void UpdateSound()
 		{
 			if (Global.Config.SoundEnabled == false || disposed)
 			{
-				soundProvider.DiscardSamples();
+				if (asyncsoundProvider != null) asyncsoundProvider.DiscardSamples();
+				if (syncsoundProvider != null) syncsoundProvider.DiscardSamples();
 				return;
 			}
 
 			int samplesNeeded = SNDDXGetAudioSpace() * 2;
 			short[] samples;
 
-			if (Global.Config.SoundThrottle && !Global.ForceNoThrottle)
+			int samplesProvided = 0;
-			{
-				if (DSoundBuffer == null) return; // can cause SNDDXGetAudioSpace() = 0
-				int samplesWanted = 2 * (int) (0.8 + 44100.0 / Global.Emulator.CoreOutputComm.VsyncRate);
 
-				while (samplesNeeded < samplesWanted)
+
-				{
+			if (Muted)
-					System.Threading.Thread.Sleep((samplesWanted - samplesNeeded) / 88); // let audio clock control sleep time
-					samplesNeeded = SNDDXGetAudioSpace() * 2;
-				}
-				samplesNeeded = samplesWanted;
-				samples = new short[samplesNeeded];
-				// no semisync
-				if (!Muted)
-					soundProvider.GetSamples(samples);
-				else
-					soundProvider.DiscardSamples();
-			}
-			else
 			{
 				if (samplesNeeded == 0)
 					return;
 				samples = new short[samplesNeeded];
-				if (soundProvider != null && Muted == false)
+				samplesProvided = samplesNeeded;
-				{
-					semisync.BaseSoundProvider = soundProvider;
-					semisync.GetSamples(samples);
-				}
-				else soundProvider.DiscardSamples();
 			}
+			else if (syncsoundProvider != null)
+			{
+				if (DSoundBuffer == null) return; // can cause SNDDXGetAudioSpace() = 0
+				int nsampgot;
+
+				syncsoundProvider.GetSamples(out samples, out nsampgot);
+
+				samplesProvided = 2 * nsampgot;
+
+				while (samplesNeeded < samplesProvided)
+				{
+					System.Threading.Thread.Sleep((samplesProvided - samplesNeeded) / 88); // let audio clock control sleep time
+					samplesNeeded = SNDDXGetAudioSpace() * 2;
+				}
+			}
+			else if (asyncsoundProvider != null)
+			{
+				if (samplesNeeded == 0)
+					return;
+				samples = new short[samplesNeeded];
+				//if (asyncsoundProvider != null && Muted == false)
+				//{
+					semisync.BaseSoundProvider = asyncsoundProvider;
+					semisync.GetSamples(samples);
+				//}
+				//else asyncsoundProvider.DiscardSamples();
+				samplesProvided = samplesNeeded;
+			}
+			else
+				return;
 			
-			//Console.WriteLine(samplesNeeded/2);
-
-
 			int cursor = soundoffset;
-			for (int i = 0; i < samples.Length; i++)
+			for (int i = 0; i < samplesProvided; i++)
 			{
 				short s = samples[i];
 				SoundBuffer[cursor++] = (byte)(s & 0xFF);
@@ -179,7 +211,7 @@ namespace BizHawk.MultiClient
 
 			DSoundBuffer.Write(SoundBuffer, 0, LockFlags.EntireBuffer);
 
-			soundoffset += samplesNeeded * 2;
+			soundoffset += samplesProvided * 2;
 			soundoffset %= BufferSize;
 		}
 

BizHawk.MultiClient/config/SoundConfig.Designer.cs

@@ -56,6 +56,7 @@
 			// OK
 			// 
 			this.OK.Anchor = ((System.Windows.Forms.AnchorStyles)((System.Windows.Forms.AnchorStyles.Bottom | System.Windows.Forms.AnchorStyles.Right)));
+			this.OK.DialogResult = System.Windows.Forms.DialogResult.OK;
 			this.OK.Location = new System.Drawing.Point(119, 209);
 			this.OK.Name = "OK";
 			this.OK.Size = new System.Drawing.Size(75, 23);