gambatte now has sound! output from the core is original 2MEGAHURTZ audio, but libspeexdsp handles it fine.

seems to be a lot of DC offset at times; not sure if there's a good way to remove it

BizHawk.Emulation/Consoles/Gambatte/Gambatte.cs

@@ -9,7 +9,7 @@ namespace BizHawk.Emulation.Consoles.Gambatte
 	/// <summary>
 	/// a gameboy/gameboy color emulator wrapped around native C++ libgambatte
 	/// </summary>
-	public class Gambatte : IEmulator, IVideoProvider
+	public class Gambatte : IEmulator, IVideoProvider, ISoundProvider
 	{
 		/// <summary>
 		/// internal gambatte state
@@ -34,6 +34,8 @@ namespace BizHawk.Emulation.Consoles.Gambatte
 			if (LibGambatte.gambatte_load(GambatteState, "gambattetmp.gb", 0) != 0)
 				throw new Exception("gambatte_load() returned non-zero (is this not a gb or gbc rom?)");
 
+
+			InitSound();
 		}
 
 		public IVideoProvider VideoProvider
@@ -43,7 +45,7 @@ namespace BizHawk.Emulation.Consoles.Gambatte
 
 		public ISoundProvider SoundProvider
 		{
-			get { return new NullSound(); }
+			get { return this; }
 		}
 
 
@@ -65,13 +67,15 @@ namespace BizHawk.Emulation.Consoles.Gambatte
 		public IController Controller { get; set; }
 
 
-		short[] soundscratch = new short[(35112 + 2064) * 2];
+		
 		uint[] videoscratch = new uint[160 * 144];
 		public void FrameAdvance(bool render)
 		{
 			uint nsamp = 35112;
 
-			LibGambatte.gambatte_runfor(GambatteState, videoscratch, 160, soundscratch, ref nsamp);
+			LibGambatte.gambatte_runfor(GambatteState, videoscratch, 160, soundbuff, ref nsamp);
+
+			soundbuffcontains = (int)nsamp;
 
 			// can't convert uint[] to int[], so we do this instead
 			// TODO: lie in the p/invoke layer and claim unsigned* is really int*
@@ -144,8 +148,8 @@ namespace BizHawk.Emulation.Consoles.Gambatte
 
 		CoreOutputComm GbOutputComm = new CoreOutputComm
 		{
-			VsyncNum = 60,
-			VsyncDen = 1,
+			VsyncNum = 262144,
+			VsyncDen = 4389,
 			RomStatusAnnotation = "Bizwhackin it up",
 			RomStatusDetails = "LEVAR BURTON"
 		};
@@ -205,5 +209,47 @@ namespace BizHawk.Emulation.Consoles.Gambatte
 		}
 
 		#endregion
+
+		#region ISoundProvider
+
+		/// <summary>
+		/// sample pairs before resampling
+		/// </summary>
+		short[] soundbuff = new short[(35112 + 2064) * 2];
+		/// <summary>
+		/// how many sample pairs are in soundbuff
+		/// </summary>
+		int soundbuffcontains = 0;
+
+		Sound.Utilities.SpeexResampler resampler;
+		Sound.MetaspuSoundProvider metaspu; 
+
+		void InitSound()
+		{
+			metaspu = new Sound.MetaspuSoundProvider(Sound.ESynchMethod.ESynchMethod_V);
+			resampler = new Sound.Utilities.SpeexResampler(5, 2097152, 44100, 2097152, 44100, metaspu.buffer.enqueue_samples);
+		}
+
+		public void GetSamples(short[] samples)
+		{
+			resampler.EnqueueSamples(soundbuff, soundbuffcontains);
+			//for (int i = 0; soundbuffcontains >= 0; soundbuffcontains--)
+			//{
+			//	resampler.EnqueueSample(soundbuff[i], soundbuff[i + 1]);
+			//	i += 2;
+			//}
+
+			soundbuffcontains = 0;
+			resampler.Flush();
+			metaspu.GetSamples(samples);
+		}
+
+		public void DiscardSamples()
+		{
+			metaspu.DiscardSamples();
+		}
+
+		public int MaxVolume { get; set; }
+		#endregion
 	}
 }

BizHawk.Emulation/Sound/Utilities/SpeexResampler.cs

@@ -264,7 +264,8 @@ namespace BizHawk.Emulation.Sound.Utilities
 		/// </summary>
 		Action<short[], int> drainer;
 
-		short[] inbuf = new short[512];
+		// TODO: this size is roughly based on how big you can make the buffer before the snes resampling (32040.5 -> 44100) gets screwed up
+		short[] inbuf = new short[512]; //[8192]; // [512];
 
 		short[] outbuf;
 
@@ -336,6 +337,27 @@ namespace BizHawk.Emulation.Sound.Utilities
 				Flush();
 		}
 
+		/// <summary>
+		/// add multiple samples to the queue
+		/// </summary>
+		/// <param name="userbuf">interleaved stereo samples</param>
+		/// <param name="nsamp">number of sample pairs</param>
+		public void EnqueueSamples(short[] userbuf, int nsamp)
+		{
+			int numused = 0;
+			while (numused < nsamp)
+			{
+				int shortstocopy = Math.Min(inbuf.Length - inbufpos, (nsamp - numused) * 2);
+
+				Buffer.BlockCopy(userbuf, numused * 2 * sizeof(short), inbuf, inbufpos * sizeof(short), shortstocopy * sizeof(short));
+				inbufpos += shortstocopy;
+				numused += shortstocopy / 2;
+
+				if (inbufpos == inbuf.Length)
+					Flush();
+			}
+		}
+
 
 		/// <summary>
 		/// flush as many input samples as possible, generating output samples right now