Coleco: Fix audio quality

BizHawk.Emulation.Cores/Consoles/Coleco/AY_3_8910_SGM.cs

@@ -8,7 +8,6 @@ namespace BizHawk.Emulation.Cores.ColecoVision
 {
 	public sealed class AY_3_8910_SGM
 	{
-		public short[] _sampleBuffer = new short[4096];
 		private short current_sample;
 
 		public AY_3_8910_SGM()
@@ -31,18 +30,11 @@ namespace BizHawk.Emulation.Cores.ColecoVision
 				Register[i] = 0x0000;
 			}
 			sync_psg_state();
-			DiscardSamples();
 		}
 
-		public void DiscardSamples()
+		public short Sample()
 		{
-			_sampleClock = 0;
+			return current_sample;
-		}
-
-		public void Sample()
-		{
-			_sampleBuffer[_sampleClock] = current_sample;
-			_sampleClock++;
 		}
 
 		private static readonly int[] VolumeTable =
@@ -51,10 +43,6 @@ namespace BizHawk.Emulation.Cores.ColecoVision
 			0x03C5, 0x0555, 0x078B, 0x0AAB, 0x0F16, 0x1555, 0x1E2B, 0x2AAA
 		};
 
-		private int _sampleClock;
-
-		private int TotalExecutedCycles;
-		private int PendingCycles;
 		private int psg_clock;
 		private int sq_per_A, sq_per_B, sq_per_C;
 		private int clock_A, clock_B, clock_C;
@@ -79,8 +67,6 @@ namespace BizHawk.Emulation.Cores.ColecoVision
 			ser.BeginSection("PSG");
 
 			ser.Sync("Register", ref Register, false);
-			ser.Sync("Toal_executed_cycles", ref TotalExecutedCycles);
-			ser.Sync("Pending_Cycles", ref PendingCycles);
 
 			ser.Sync("psg_clock", ref psg_clock);
 			ser.Sync("clock_A", ref clock_A);
@@ -296,9 +282,9 @@ namespace BizHawk.Emulation.Cores.ColecoVision
 					}
 					else
 					{
-						v = (short)(sound_out_A ? VolumeTable[env_E] : 0);
+						v = (short)(sound_out_A ? VolumeTable[vol_A] : 0);
 					}
-
+					
 					if (env_vol_B == 0)
 					{
 						v += (short)(sound_out_B ? VolumeTable[vol_B] : 0);
@@ -317,7 +303,7 @@ namespace BizHawk.Emulation.Cores.ColecoVision
 					{
 						v += (short)(sound_out_C ? VolumeTable[env_E] : 0);
 					}
-
+					
 					current_sample = (short)v;
 				}
 			}

BizHawk.Emulation.Cores/Consoles/Coleco/ColecoVision.IEmulator.cs

@@ -73,6 +73,8 @@ namespace BizHawk.Emulation.Cores.ColecoVision
 			int changes_1 = change1 > 0 ? (int)Math.Floor(change1) : (int)Math.Ceiling(change1);
 			int changes_2 = change2 > 0 ? (int)Math.Floor(change2) : (int)Math.Ceiling(change2);
 
+			
+
 			for (int scanLine = 0; scanLine < 262; scanLine++)
 			{
 				_vdp.RenderScanline(scanLine);
@@ -92,11 +94,20 @@ namespace BizHawk.Emulation.Cores.ColecoVision
 					_cpu.ExecuteOne();
 
 					// pick out sound samples from the sound devies twice per scanline
-					if ((i==76) || (i==152))
+					int v = PSG.Sample();
+
+					if (use_SGM)
 					{
-						PSG.Sample();
+						v += SGM_sound.Sample();
-						if (use_SGM) { SGM_sound.Sample(); }
 					}
+
+					if (v != _latchedSample)
+					{
+						_blip.AddDelta((uint)_sampleClock, v - _latchedSample);
+						_latchedSample = v;
+					}
+
+					_sampleClock++;	
 				}
 
 				// starting from scanline 20, changes to the wheel are added once per scanline (up to 144)
@@ -163,6 +174,8 @@ namespace BizHawk.Emulation.Cores.ColecoVision
 		public bool enable_SGM_low = false;
 		public byte port_0x53, port_0x7F;
 
+		public int _sampleClock = 0;
+		public int _latchedSample = 0;
 
 		public int Frame => _frame;
 

BizHawk.Emulation.Cores/Consoles/Coleco/ColecoVision.ISoundProvider.cs

@@ -11,12 +11,12 @@ namespace BizHawk.Emulation.Cores.ColecoVision
 		private SN76489col PSG;
 		private AY_3_8910_SGM SGM_sound;
 
-		private short[] _sampleBuffer = new short[0];
+		private readonly BlipBuffer _blip = new BlipBuffer(4096);
 
 		public void DiscardSamples()
 		{
-			SGM_sound.DiscardSamples();
+			_blip.Clear();
-			PSG.DiscardSamples();
+			_sampleClock = 0;
 		}
 
 		public void GetSamplesAsync(short[] samples)
@@ -38,26 +38,18 @@ namespace BizHawk.Emulation.Cores.ColecoVision
 
 		public void GetSamplesSync(out short[] samples, out int nsamp)
 		{
-			nsamp = 524;
+			_blip.EndFrame((uint)_sampleClock);
+			_sampleClock = 0;
 
+			nsamp = _blip.SamplesAvailable();
 			samples = new short[nsamp * 2];
 
-			for (int i = 0; i < nsamp; i++)
+			_blip.ReadSamples(samples, nsamp, true);
-			{
-				samples[i * 2] = PSG._sampleBuffer[i];
-				samples[i * 2 + 1] = PSG._sampleBuffer[i];
-			}
 
-			if (use_SGM)
+			for (int i = 0; i < nsamp * 2; i += 2)
 			{
-				for (int i = 0; i < nsamp; i++)
+				samples[i + 1] = samples[i];
-				{
+			}				
-					samples[i * 2] += SGM_sound._sampleBuffer[i];
-					samples[i * 2 + 1] += SGM_sound._sampleBuffer[i];
-				}
-			}
-
-			DiscardSamples();
 		}
 
 		public void GetSamples(short[] samples)

BizHawk.Emulation.Cores/Consoles/Coleco/ColecoVision.cs

@@ -35,6 +35,7 @@ namespace BizHawk.Emulation.Cores.ColecoVision
 
 			PSG = new SN76489col();
 			SGM_sound = new AY_3_8910_SGM();
+			_blip.SetRates(3579545, 44100);
 
 			ControllerDeck = new ColecoVisionControllerDeck(_syncSettings.Port1, _syncSettings.Port2);
 

BizHawk.Emulation.Cores/Consoles/Coleco/SN76489col.cs

@@ -9,7 +9,6 @@ namespace BizHawk.Emulation.Cores.ColecoVision
 {
 	public sealed class SN76489col
 	{
-		public short[] _sampleBuffer = new short[4096];
 		private short current_sample;
 
 		public SN76489col()
@@ -26,8 +25,6 @@ namespace BizHawk.Emulation.Cores.ColecoVision
 		public int noise_rate;
 		public bool noise_bit;
 
-		private int _sampleClock;
-
 		private int psg_clock;
 
 		private int clock_A, clock_B, clock_C;
@@ -47,19 +44,11 @@ namespace BizHawk.Emulation.Cores.ColecoVision
 
 			// reset the shift register
 			noise = 0x40000;
-
-			DiscardSamples();
 		}
 
-		public void DiscardSamples()
+		public int Sample()
 		{
-			_sampleClock = 0;
+			return current_sample;
-		}
-
-		public void Sample()
-		{
-			_sampleBuffer[_sampleClock] = current_sample;
-			_sampleClock++;
 		}
 
 		public void SyncState(Serializer ser)
@@ -81,7 +70,6 @@ namespace BizHawk.Emulation.Cores.ColecoVision
 			ser.Sync("noise_bit", ref noise_bit);
 
 			ser.Sync("psg_clock", ref psg_clock);
-			ser.Sync("sample_clock", ref _sampleClock);
 
 			ser.Sync("A_up", ref A_up);
 			ser.Sync("B_up", ref B_up);