Audio: Added cubic interpolation option

Core/SPC_DSP.cpp

@@ -20,6 +20,7 @@ Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */
 
 #include "blargg_source.h"
 #include "Spc.h"
+#include "EmuSettings.h"
 
 #ifdef BLARGG_ENABLE_OPTIMIZER
 	#include BLARGG_ENABLE_OPTIMIZER
@@ -131,6 +132,25 @@ static short const gauss [512] =
 1299,1300,1300,1301,1302,1302,1303,1303,1303,1304,1304,1304,1304,1304,1305,1305,
 };
 
+inline int SPC_DSP::interpolate_cubic(voice_t const* v)
+{
+	int const* in = &v->buf[(v->interp_pos >> 12) + v->buf_pos];
+
+	float v0 = in[0] / 32768.0;
+	float v1 = in[1] / 32768.0;
+	float v2 = in[2] / 32768.0;
+	float v3 = in[3] / 32768.0;
+
+	float a = (v3 - v2) - (v0 - v1);
+	float b = (v0 - v1) - a;
+	float c = v2 - v0;
+	float d = v1;
+	
+	float ratio = (double)(v->interp_pos & 0xFFF) / 0x1000;
+
+	return (int)((d + ratio * (c + ratio * (b + ratio * a))) * 32768);
+}
+
 inline int SPC_DSP::interpolate( voice_t const* v )
 {
 	// Make pointers into gaussian based on fractional position between samples
@@ -451,7 +471,7 @@ VOICE_CLOCK( V3c )
 	
 	// Gaussian interpolation
 	{
-		int output = interpolate( v );
+		int output = _settings->GetAudioConfig().EnableCubicInterpolation ? interpolate_cubic(v) : interpolate( v );
 		
 		// Noise
 		if ( m.t_non & v->vbit )
@@ -812,9 +832,10 @@ inline void SPC_DSP::writeRam(uint16_t addr, uint8_t value) { _spc->DspWriteRam(
 
 //// Setup
 
-void SPC_DSP::init( Spc *spc, void* ram_64k )
+void SPC_DSP::init( Spc *spc, EmuSettings *settings, void* ram_64k )
 {
 	_spc = spc;
+	_settings = settings;
 	m.ram = (uint8_t*) ram_64k;
 	mute_voices( 0 );
 	disable_surround( false );

Core/SPC_DSP.h

@@ -8,6 +8,7 @@
 extern "C" { typedef void (*dsp_copy_func_t)( unsigned char** io, void* state, size_t ); }
 
 class Spc;
+class EmuSettings;
 class SPC_DSP {
 public:
 	typedef BOOST::uint8_t uint8_t;
@@ -15,7 +16,7 @@ public:
 // Setup
 
 	// Initializes DSP and has it use the 64K RAM provided
-	void init( Spc* spc, void* ram_64k );
+	void init( Spc* spc, EmuSettings* settings, void* ram_64k );
 
 	// Sets destination for output samples. If out is NULL or out_size is 0,
 	// doesn't generate any.
@@ -191,11 +192,13 @@ private:
 	};
 	state_t m;
 	Spc* _spc;
+	EmuSettings* _settings;
 	
 	void init_counter();
 	void run_counters();
 	unsigned read_counter( int rate );
 	
+	int interpolate_cubic(voice_t const* v);
 	int  interpolate( voice_t const* v );
 	void run_envelope( voice_t* const v );
 	void decode_brr( voice_t* v );

Core/SettingTypes.h

@@ -119,6 +119,8 @@ struct AudioConfig
 	uint32_t SampleRate = 48000;
 	uint32_t AudioLatency = 60;
 
+	bool EnableCubicInterpolation  = true;
+
 	bool MuteSoundInBackground = false;
 	bool ReduceSoundInBackground = true;
 	bool ReduceSoundInFastForward = false;

Core/Spc.cpp

@@ -25,7 +25,7 @@ Spc::Spc(Console* console)
 
 	_dsp.reset(new SPC_DSP());
 	#ifndef DUMMYSPC
-	_dsp->init(this, _ram);
+	_dsp->init(this, _console->GetSettings().get(), _ram);
 	#endif
 	_dsp->reset();
 	_dsp->set_output(_soundBuffer, Spc::SampleBufferSize >> 1);

Libretro/libretro.cpp

@@ -42,6 +42,7 @@ static constexpr const char* MesenNtscFilter = "mesen-s_ntsc_filter";
 static constexpr const char* MesenRegion = "mesen-s_region";
 static constexpr const char* MesenAspectRatio = "mesen-s_aspect_ratio";
 static constexpr const char* MesenBlendHighRes = "mesen-s_blend_high_res";
+static constexpr const char* MesenCubicInterpolation = "mesen-s_cubic_interpolation";
 static constexpr const char* MesenOverscanVertical = "mesen-s_overscan_vertical";
 static constexpr const char* MesenOverscanHorizontal = "mesen-s_overscan_horizontal";
 static constexpr const char* MesenRamState = "mesen-s_ramstate";
@@ -114,6 +115,7 @@ extern "C" {
 			{ MesenOverscanHorizontal, "Horizontal Overscan; None|8px|16px" },
 			{ MesenAspectRatio, "Aspect Ratio; Auto|No Stretching|NTSC|PAL|4:3|16:9" },
 			{ MesenBlendHighRes, "Blend Hi-Res Modes; disabled|enabled" },
+			{ MesenCubicInterpolation, "Cubic Interpolation (Audio); disabled|enabled" },
 			{ MesenOverclock, "Overclock; None|Low|Medium|High|Very High" },
 			{ MesenOverclockType, "Overclock Type; Before NMI|After NMI" },
 			{ MesenSuperFxOverclock, "Super FX Clock Speed; 100%|200%|300%|400%|500%|1000%" },
@@ -208,6 +210,7 @@ extern "C" {
 	{
 		struct retro_variable var = { };
 		VideoConfig video = _console->GetSettings()->GetVideoConfig();
+		AudioConfig audio = _console->GetSettings()->GetAudioConfig();
 		EmulationConfig emulation = _console->GetSettings()->GetEmulationConfig();
 		InputConfig input = _console->GetSettings()->GetInputConfig();
 		video.Brightness = 0;
@@ -378,6 +381,11 @@ extern "C" {
 			string value = string(var.value);
 			video.BlendHighResolutionModes = (value == "enabled");
 		}
+		
+		if(readVariable(MesenCubicInterpolation, var)) {
+			string value = string(var.value);
+			audio.EnableCubicInterpolation = (value == "enabled");
+		}
 
 		auto getKeyCode = [=](int port, int retroKey) {
 			return (port << 8) | (retroKey + 1);
@@ -412,6 +420,7 @@ extern "C" {
 		_console->GetSettings()->SetVideoConfig(video);
 		_console->GetSettings()->SetEmulationConfig(emulation);
 		_console->GetSettings()->SetInputConfig(input);
+		_console->GetSettings()->SetAudioConfig(audio);
 
 		retro_system_av_info avInfo = {};
 		_renderer->GetSystemAudioVideoInfo(avInfo);

UI/Config/AudioConfig.cs

@@ -18,6 +18,8 @@ namespace Mesen.GUI.Config
 		[ValidValues(11025, 22050, 32000, 44100, 48000, 96000)] public UInt32 SampleRate = 48000;
 		[MinMax(15, 300)] public UInt32 AudioLatency = 60;
 
+		[MarshalAs(UnmanagedType.I1)] public bool EnableCubicInterpolation = true;
+
 		[MarshalAs(UnmanagedType.I1)] public bool MuteSoundInBackground = false;
 		[MarshalAs(UnmanagedType.I1)] public bool ReduceSoundInBackground = true;
 		[MarshalAs(UnmanagedType.I1)] public bool ReduceSoundInFastForward = false;

UI/Dependencies/resources.en.xml

@@ -119,32 +119,13 @@
 			<Control ID="tpgGeneral">General</Control>
 			<Control ID="tpgAdvanced">Advanced</Control>
 			<Control ID="chkDisableDynamicSampleRate">Disable dynamic sample rate</Control>
-			<Control ID="chkSwapDutyCycles">Swap square channels duty cycles (Mimics old clones)</Control>
-			<Control ID="chkSilenceTriangleHighFreq">Mute ultrasonic frequencies on triangle channel (reduces popping)</Control>
-			<Control ID="chkReduceDmcPopping">Reduce popping sounds on the DMC channel</Control>
-			<Control ID="chkDisableNoiseModeFlag">Disable noise channel mode flag</Control>
-			<Control ID="tpgEffects">Effects</Control>
-			<Control ID="grpStereo">Stereo</Control>
-			<Control ID="radStereoDisabled">Disabled</Control>
-			<Control ID="radStereoDelay">Delay</Control>
-			<Control ID="radStereoPanning">Panning</Control>
-			<Control ID="lblStereoDelayMs">ms</Control>
-			<Control ID="lblStereoPanningAngle">(Angle in degrees)</Control>
-			<Control ID="radStereoCombFilter">Comb Filter</Control>
-			<Control ID="lblStereoCombFilterMs">ms</Control>
-			<Control ID="lblStereoCombFilterDelay">Delay:</Control>
-			<Control ID="lblStereoCombFilterStrength">Strength:</Control>
-			<Control ID="chkCrossFeedEnabled">Enable Crossfeed:</Control>
-			<Control ID="grpReverb">Reverb</Control>
-			<Control ID="chkReverbEnabled">Enable Reverb</Control>
-			<Control ID="lblReverbDelay">Delay:</Control>
-			<Control ID="lblReverbStrength">Strength:</Control>
 			<Control ID="chkMuteSoundInBackground">Mute sound when in background</Control>
 			<Control ID="chkReduceSoundInBackground">Reduce volume when in background</Control>
 			<Control ID="chkReduceSoundInFastForward">Reduce volume during fast forward/rewind</Control>
 			<Control ID="trkVolumeReduction">Volume Reduction (%)</Control>
 			<Control ID="lblVolumeReductionSettings">Volume Reduction Settings</Control>
 			<Control ID="chkEnableAudio">Enable Audio</Control>
+			<Control ID="chkEnableCubicInterpolation">Enable cubic interpolation</Control>
 			<Control ID="lblSampleRate">Sample Rate:</Control>
 			<Control ID="lblLatencyMs">ms</Control>
 			<Control ID="lblLatencyWarning">Low values may cause sound problems</Control>

UI/Forms/Config/frmAudioConfig.Designer.cs

@@ -76,6 +76,7 @@
 			this.tpgAdvanced = new System.Windows.Forms.TabPage();
 			this.tableLayoutPanel1 = new System.Windows.Forms.TableLayoutPanel();
 			this.chkDisableDynamicSampleRate = new Mesen.GUI.Controls.ctrlRiskyOption();
+			this.chkEnableCubicInterpolation = new System.Windows.Forms.CheckBox();
 			this.tabControl1.SuspendLayout();
 			this.tpgGeneral.SuspendLayout();
 			this.tableLayoutPanel2.SuspendLayout();
@@ -298,6 +299,7 @@
             0,
             0,
             0});
+			this.nudLatency.IsHex = false;
 			this.nudLatency.Location = new System.Drawing.Point(3, 3);
 			this.nudLatency.Maximum = new decimal(new int[] {
             300,
@@ -890,11 +892,13 @@
 			// 
 			this.tableLayoutPanel1.ColumnCount = 1;
 			this.tableLayoutPanel1.ColumnStyles.Add(new System.Windows.Forms.ColumnStyle(System.Windows.Forms.SizeType.Percent, 100F));
-			this.tableLayoutPanel1.Controls.Add(this.chkDisableDynamicSampleRate, 0, 0);
+			this.tableLayoutPanel1.Controls.Add(this.chkDisableDynamicSampleRate, 0, 1);
+			this.tableLayoutPanel1.Controls.Add(this.chkEnableCubicInterpolation, 0, 0);
 			this.tableLayoutPanel1.Dock = System.Windows.Forms.DockStyle.Fill;
 			this.tableLayoutPanel1.Location = new System.Drawing.Point(3, 3);
 			this.tableLayoutPanel1.Name = "tableLayoutPanel1";
-			this.tableLayoutPanel1.RowCount = 2;
+			this.tableLayoutPanel1.RowCount = 3;
+			this.tableLayoutPanel1.RowStyles.Add(new System.Windows.Forms.RowStyle());
 			this.tableLayoutPanel1.RowStyles.Add(new System.Windows.Forms.RowStyle());
 			this.tableLayoutPanel1.RowStyles.Add(new System.Windows.Forms.RowStyle(System.Windows.Forms.SizeType.Percent, 100F));
 			this.tableLayoutPanel1.Size = new System.Drawing.Size(478, 346);
@@ -903,12 +907,22 @@
 			// chkDisableDynamicSampleRate
 			// 
 			this.chkDisableDynamicSampleRate.Checked = false;
-			this.chkDisableDynamicSampleRate.Location = new System.Drawing.Point(0, 0);
+			this.chkDisableDynamicSampleRate.Location = new System.Drawing.Point(0, 23);
 			this.chkDisableDynamicSampleRate.Name = "chkDisableDynamicSampleRate";
 			this.chkDisableDynamicSampleRate.Size = new System.Drawing.Size(463, 24);
 			this.chkDisableDynamicSampleRate.TabIndex = 5;
 			this.chkDisableDynamicSampleRate.Text = "Disable dynamic sample rate";
 			// 
+			// chkEnableCubicInterpolation
+			// 
+			this.chkEnableCubicInterpolation.AutoSize = true;
+			this.chkEnableCubicInterpolation.Location = new System.Drawing.Point(3, 3);
+			this.chkEnableCubicInterpolation.Name = "chkEnableCubicInterpolation";
+			this.chkEnableCubicInterpolation.Size = new System.Drawing.Size(148, 17);
+			this.chkEnableCubicInterpolation.TabIndex = 6;
+			this.chkEnableCubicInterpolation.Text = "Enable cubic interpolation";
+			this.chkEnableCubicInterpolation.UseVisualStyleBackColor = true;
+			// 
 			// frmAudioConfig
 			// 
 			this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
@@ -938,6 +952,7 @@
 			this.tlpEqualizer.ResumeLayout(false);
 			this.tpgAdvanced.ResumeLayout(false);
 			this.tableLayoutPanel1.ResumeLayout(false);
+			this.tableLayoutPanel1.PerformLayout();
 			this.ResumeLayout(false);
 			this.PerformLayout();
 
@@ -994,5 +1009,6 @@
 		private System.Windows.Forms.TabPage tpgAdvanced;
 		private System.Windows.Forms.TableLayoutPanel tableLayoutPanel1;
 		private Controls.ctrlRiskyOption chkDisableDynamicSampleRate;
-	}
+	  private System.Windows.Forms.CheckBox chkEnableCubicInterpolation;
+   }
 }

UI/Forms/Config/frmAudioConfig.cs

@@ -30,6 +30,8 @@ namespace Mesen.GUI.Forms.Config
 			AddBinding(nameof(AudioConfig.SampleRate), cboSampleRate);
 			AddBinding(nameof(AudioConfig.AudioDevice), cboAudioDevice);
 			AddBinding(nameof(AudioConfig.DisableDynamicSampleRate), chkDisableDynamicSampleRate);
+			
+			AddBinding(nameof(AudioConfig.EnableCubicInterpolation), chkEnableCubicInterpolation);
 
 			AddBinding(nameof(AudioConfig.EnableEqualizer), chkEnableEqualizer);
 			AddBinding(nameof(AudioConfig.Band1Gain), trkBand1Gain);