martin@0: /*
martin@0:  *  Decoder.cpp
martin@0:  *  SoundField
martin@0:  *
martin@0:  *  Created by Martin Morrell on 14/06/2012.
martin@0:  *  Copyright 2012 Queen Mary University of London. All rights reserved.
martin@0:  *
martin@0:  */
martin@0: 
martin@0: 
martin@0: #include "Decoder.h"
martin@0: #define _USE_MATH_DEFINES
martin@0: #include <cmath>
martin@0: #include <stdlib.h>
martin@0: #define RearVerbWidth 55
martin@0: #define RearVerbPattern 0.5
martin@0: #define HiVerbWidth 30
martin@0: #define HiVerbPattern 0.5
martin@0: 
martin@0: 
martin@0: double Decoder::degRad(double angle)
martin@0: {
martin@0: 	return (angle/180*M_PI);
martin@0: };
martin@0: 
martin@0: 
martin@0: double Decoder::radDeg(double angle)
martin@0: {
martin@0: 	return (angle/M_PI*180);
martin@0: };
martin@0: 
martin@0: 
martin@0: //Overall Functions
martin@0: void Decoder::monoDecoder(double &w, double &x, double &y, double &z)
martin@0: {
martin@0: 	//Sound field rotations. Only called if the value is not 0 
martin@0: 	if (Rotate!=0.0f)
martin@0: 		rotateField(x, y);
martin@0: 	
martin@0: 	if (Tilt!=0.0f)
martin@0: 		tiltField(y, z);
martin@0: 	
martin@0: 	if (Tumble!=0.0f)
martin@0: 		tumbleField(x, z);
martin@0: 	
martin@0: 	
martin@0: 	//Zoom function. Only called if the value is not 0 
martin@0: 	if (Zoom!=0.0f) {
martin@0: 		switch (ZoomMethod) {
martin@0: 			case 0:
martin@0: 				dominanceZoom(w, x, y, z);
martin@0: 				break;
martin@0: 			case 1:
martin@0: 				pressZoom(w, x, y, z);
martin@0: 				break;
martin@0: 			case 2:
martin@0: 				pushZoom(w, x, y, z);
martin@0: 				break;
martin@0: 			case 3:
martin@0: 				focusZoom(w, x, y, z);
martin@0: 				break;
martin@0: 				
martin@0: 			default:
martin@0: 				break;
martin@0: 		}
martin@0: 	}
martin@0: 	
martin@0: 	
martin@0: 	//Centre virtual mic
martin@0:     centreMic(w, x);
martin@0: 	
martin@0: };
martin@0: 
martin@0: 
martin@0: void Decoder::stereoDecoder(double &w, double &x, double &y, double &z)
martin@0: {
martin@0: 	//Sound field rotations. Only called if the value is not 0 
martin@0: 	if (Rotate!=0.0f)
martin@0: 		rotateField(x, y);
martin@0: 	
martin@0: 	if (Tilt!=0.0f)
martin@0: 		tiltField(y, z);
martin@0: 	
martin@0: 	if (Tumble!=0.0f)
martin@0: 		tumbleField(x, z);
martin@0: 	
martin@0: 	
martin@0: 	//Zoom function. Only called if the value is not 0 
martin@0: 	if (Zoom!=0.0f) {
martin@0: 		switch (ZoomMethod) {
martin@0: 			case 0:
martin@0: 				dominanceZoom(w, x, y, z);
martin@0: 				break;
martin@0: 			case 1:
martin@0: 				pressZoom(w, x, y, z);
martin@0: 				break;
martin@0: 			case 2:
martin@0: 				pushZoom(w, x, y, z);
martin@0: 				break;
martin@0: 			case 3:
martin@0: 				focusZoom(w, x, y, z);
martin@0: 				break;
martin@0: 				
martin@0: 			default:
martin@0: 				break;
martin@0: 		}
martin@0: 	}
martin@0: 	
martin@0: 	
martin@0: 	switch (Mode) {
martin@0: 		case 0:
martin@0: 			xyDecode(w, x, y, z);
martin@0: 			break;
martin@0: 		case 1:
martin@0: 			msDecode(w, x, y, z);
martin@0: 			break;	
martin@0: 		default:
martin@0: 			break;
martin@0: 	}
martin@0: 	
martin@0: 
martin@0: 	if (RearVerb > -40) {
martin@0: 		rearVerb(w, x, y, z);
martin@0: 	}
martin@0: 	
martin@0: 	if (HiVerb >-40) {
martin@0: 		hiVerb(w, x, y, z);
martin@0: 	}
martin@0: };
martin@0: 
martin@0: 
martin@0: void Decoder::twoOneDecoder(double &w, double &x, double &y, double &z)
martin@0: {
martin@0: 	//Sound field rotations. Only called if the value is not 0 
martin@0: 	if (Rotate!=0.0f)
martin@0: 		rotateField(x, y);
martin@0: 	
martin@0: 	if (Tilt!=0.0f)
martin@0: 		tiltField(y, z);
martin@0: 	
martin@0: 	if (Tumble!=0.0f)
martin@0: 		tumbleField(x, z);
martin@0: 	
martin@0: 	
martin@0: 	//Zoom function. Only called if the value is not 0 
martin@0: 	if (Zoom!=0.0f) {
martin@0: 		switch (ZoomMethod) {
martin@0: 			case 0:
martin@0: 				dominanceZoom(w, x, y, z);
martin@0: 				break;
martin@0: 			case 1:
martin@0: 				pressZoom(w, x, y, z);
martin@0: 				break;
martin@0: 			case 2:
martin@0: 				pushZoom(w, x, y, z);
martin@0: 				break;
martin@0: 			case 3:
martin@0: 				focusZoom(w, x, y, z);
martin@0: 				break;
martin@0: 				
martin@0: 			default:
martin@0: 				break;
martin@0: 		}
martin@0: 	}
martin@0: 	
martin@0:     //Subwoofer signal and filtering
martin@0:     subSignal(w);
martin@0:     filterLF();
martin@0:     if (Fc>0) {
martin@0:         filterHF(w, x, y, z);
martin@0:     }
martin@0:     
martin@0:     
martin@0:     
martin@0:     //Front virtual mics
martin@0:  	switch (Mode) {
martin@0: 		case 0:
martin@0: 			xyDecode(w, x, y, z);
martin@0: 			break;
martin@0: 		case 1:
martin@0: 			msDecode(w, x, y, z);
martin@0: 			break;	
martin@0: 		default:
martin@0: 			break;
martin@0: 	}   
martin@0:     
martin@0:     
martin@0:     //Reverbs
martin@0:     if (RearVerb > -40) {
martin@0: 		rearVerb(w, x, y, z);
martin@0: 	}
martin@0: 	
martin@0: 	if (HiVerb >-40) {
martin@0: 		hiVerb(w, x, y, z);
martin@0: 	}
martin@0: 	
martin@0: };
martin@0: 
martin@0: 
martin@0: 
martin@0: void Decoder::lrcsDecoder(double &w, double &x, double &y, double &z)
martin@0: {
martin@0: 	//Sound field rotations. Only called if the value is not 0 
martin@0: 	if (Rotate!=0.0f)
martin@0: 		rotateField(x, y);
martin@0: 	
martin@0: 	if (Tilt!=0.0f)
martin@0: 		tiltField(y, z);
martin@0: 	
martin@0: 	if (Tumble!=0.0f)
martin@0: 		tumbleField(x, z);
martin@0: 	
martin@0: 	
martin@0: 	//Zoom function. Only called if the value is not 0 
martin@0: 	if (Zoom!=0.0f) {
martin@0: 		switch (ZoomMethod) {
martin@0: 			case 0:
martin@0: 				dominanceZoom(w, x, y, z);
martin@0: 				break;
martin@0: 			case 1:
martin@0: 				pressZoom(w, x, y, z);
martin@0: 				break;
martin@0: 			case 2:
martin@0: 				pushZoom(w, x, y, z);
martin@0: 				break;
martin@0: 			case 3:
martin@0: 				focusZoom(w, x, y, z);
martin@0: 				break;
martin@0: 				
martin@0: 			default:
martin@0: 				break;
martin@0: 		}
martin@0: 	}
martin@0: 	
martin@0:     
martin@0:     //Front virtual mics
martin@0:  	switch (Mode) {
martin@0: 		case 0:
martin@0: 			xyDecode(w, x, y, z);
martin@0: 			break;
martin@0: 		case 1:
martin@0: 			msDecode(w, x, y, z);
martin@0: 			break;	
martin@0: 		default:
martin@0: 			break;
martin@0: 	}   
martin@0:     
martin@0: 	//Rear virtual mics
martin@0: 	switch (surMode) {
martin@0: 		case 0:
martin@0: 			xySurDecode(w, x, y, z);
martin@0: 			break;
martin@0: 		case 1:
martin@0: 			msSurDecode(w, x, y, z);
martin@0: 			break;	
martin@0: 		default:
martin@0: 			break;
martin@0: 	}
martin@0: 	
martin@0:     
martin@0: };
martin@0: 
martin@0: 
martin@0: 
martin@0: void Decoder::fiveDecoder(double &w, double &x, double &y, double &z)
martin@0: {
martin@0: 	//Sound field rotations. Only called if the value is not 0 
martin@0: 	if (Rotate!=0.0f)
martin@0: 		rotateField(x, y);
martin@0: 	
martin@0: 	if (Tilt!=0.0f)
martin@0: 		tiltField(y, z);
martin@0: 	
martin@0: 	if (Tumble!=0.0f)
martin@0: 		tumbleField(x, z);
martin@0: 	
martin@0: 	
martin@0: 	//Zoom function. Only called if the value is not 0 
martin@0: 	if (Zoom!=0.0f) {
martin@0: 		switch (ZoomMethod) {
martin@0: 			case 0:
martin@0: 				dominanceZoom(w, x, y, z);
martin@0: 				break;
martin@0: 			case 1:
martin@0: 				pressZoom(w, x, y, z);
martin@0: 				break;
martin@0: 			case 2:
martin@0: 				pushZoom(w, x, y, z);
martin@0: 				break;
martin@0: 			case 3:
martin@0: 				focusZoom(w, x, y, z);
martin@0: 				break;
martin@0: 				
martin@0: 			default:
martin@0: 				break;
martin@0: 		}
martin@0: 	}
martin@0: 	
martin@0:     
martin@0:     //Centre virtual mic
martin@0:     centreMic(w, x);
martin@0:     
martin@0:     //Front virtual mics
martin@0:  	switch (Mode) {
martin@0: 		case 0:
martin@0: 			xyDecode(w, x, y, z);
martin@0: 			break;
martin@0: 		case 1:
martin@0: 			msDecode(w, x, y, z);
martin@0: 			break;	
martin@0: 		default:
martin@0: 			break;
martin@0: 	}   
martin@0:     
martin@0: 	//Rear virtual mics
martin@0: 	switch (surMode) {
martin@0: 		case 0:
martin@0: 			xySurDecode(w, x, y, z);
martin@0: 			break;
martin@0: 		case 1:
martin@0: 			msSurDecode(w, x, y, z);
martin@0: 			break;	
martin@0: 		default:
martin@0: 			break;
martin@0: 	}
martin@0: 	
martin@0:     
martin@0: };
martin@0: 
martin@0: 
martin@0: 
martin@0: void Decoder::fiveOneDecoder(double &w, double &x, double &y, double &z)
martin@0: {
martin@0: 	//Sound field rotations. Only called if the value is not 0 
martin@0: 	if (Rotate!=0.0f)
martin@0: 		rotateField(x, y);
martin@0: 	
martin@0: 	if (Tilt!=0.0f)
martin@0: 		tiltField(y, z);
martin@0: 	
martin@0: 	if (Tumble!=0.0f)
martin@0: 		tumbleField(x, z);
martin@0: 	
martin@0: 	
martin@0: 	//Zoom function. Only called if the value is not 0 
martin@0: 	if (Zoom!=0.0f) {
martin@0: 		switch (ZoomMethod) {
martin@0: 			case 0:
martin@0: 				dominanceZoom(w, x, y, z);
martin@0: 				break;
martin@0: 			case 1:
martin@0: 				pressZoom(w, x, y, z);
martin@0: 				break;
martin@0: 			case 2:
martin@0: 				pushZoom(w, x, y, z);
martin@0: 				break;
martin@0: 			case 3:
martin@0: 				focusZoom(w, x, y, z);
martin@0: 				break;
martin@0: 				
martin@0: 			default:
martin@0: 				break;
martin@0: 		}
martin@0: 	}
martin@0: 	
martin@0:     //Subwoofer signal and filtering
martin@0:     subSignal(w);
martin@0:     filterLF();
martin@0:     if (Fc>0) {
martin@0:         filterHF(w, x, y, z);
martin@0:     }
martin@0:     
martin@0:     //Centre virtual mic
martin@0:     centreMic(w, x);
martin@0:     
martin@0:     //Front virtual mics
martin@0:  	switch (Mode) {
martin@0: 		case 0:
martin@0: 			xyDecode(w, x, y, z);
martin@0: 			break;
martin@0: 		case 1:
martin@0: 			msDecode(w, x, y, z);
martin@0: 			break;	
martin@0: 		default:
martin@0: 			break;
martin@0: 	}   
martin@0:     
martin@0: 	//Rear virtual mics
martin@0: 	switch (surMode) {
martin@0: 		case 0:
martin@0: 			xySurDecode(w, x, y, z);
martin@0: 			break;
martin@0: 		case 1:
martin@0: 			msSurDecode(w, x, y, z);
martin@0: 			break;	
martin@0: 		default:
martin@0: 			break;
martin@0: 	}
martin@0: 	
martin@0:     
martin@0: };
martin@0: 
martin@0: 
martin@0: 
martin@0: 
martin@0: 
martin@0: 
martin@0: //SoundField Rotations
martin@0: void Decoder::rotateField(double &x, double &y)
martin@0: {	
martin@1: 	double temp = x;
martin@0: 	x = cos(degRad(Rotate))*temp - sin(degRad(Rotate))*y;
martin@0: 	y = cos(degRad(Rotate))*y + sin(degRad(Rotate))*temp;
martin@0: 	
martin@0: };
martin@0: 
martin@0: 
martin@0: void Decoder::tiltField(double &y, double &z)
martin@0: {
martin@1: 	double temp = y;
martin@0: 	y = cos(degRad(Tilt))*temp - sin(degRad(Tilt))*z;
martin@0: 	z = cos(degRad(Tilt))*z + sin(degRad(Tilt))*temp;	
martin@0: };
martin@0: 
martin@0: 
martin@0: void Decoder::tumbleField(double &x, double &z)
martin@0: {
martin@1: 	double temp = x;
martin@0: 	x = cos(degRad(Tumble))*temp - sin(degRad(Tumble))*z;
martin@0: 	z = cos(degRad(Tumble))*z + sin(degRad(Tumble))*temp;
martin@0: };
martin@0: 
martin@0: 
martin@0: 
martin@0: 
martin@0: //Zoom Methods
martin@0: void Decoder::dominanceZoom(double &w, double &x, double &y, double &z)
martin@0: {
martin@0: 	double lambda = pow(10,(Zoom*0.24/20));
martin@1:     double temp[4];
martin@1: 	temp[0]=w;
martin@1: 	temp[1]=x;
martin@1: 	temp[2]=y;
martin@1: 	temp[3]=z;
martin@0: 	
martin@1: 	w = 0.5*(lambda+pow(lambda,-1))*temp[0] + pow(8,-0.5)*(lambda-pow(lambda,-1))*temp[1];
martin@1: 	x = 0.5*(lambda+pow(lambda,-1))*temp[1] + pow(2,-0.5)*(lambda-pow(lambda,-1))*temp[0];
martin@0: };
martin@0: 
martin@0: 
martin@0: void Decoder::pressZoom(double &w, double &x, double &y, double &z)
martin@0: {
martin@1:     double temp[4];
martin@1: 	temp[0]=w;
martin@1: 	temp[1]=x;
martin@1: 	temp[2]=y;
martin@1: 	temp[3]=z;
martin@0: 	
martin@1: 	x = (sqrt(2.0)*std::abs(sin(degRad(Zoom*0.9)))*sin(degRad(Zoom*0.9))*temp[0]) + (pow(cos(degRad(Zoom*0.9)),2)*temp[1]);
martin@1: 	y = cos(degRad(Zoom*0.9))*temp[2];
martin@1: 	z = cos(degRad(Zoom*0.9))*temp[3];
martin@0: };
martin@0: 
martin@0: 
martin@0: void Decoder::pushZoom(double &w, double &x, double &y, double &z)
martin@0: {
martin@1:     double temp[4];
martin@1: 	temp[0]=w;
martin@1: 	temp[1]=x;
martin@1: 	temp[2]=y;
martin@1: 	temp[3]=z;
martin@0:     
martin@1: 	x = (sqrt(2.0)*std::abs(sin(degRad(Zoom*0.9)))*sin(degRad(Zoom*0.9))*temp[0]) + (pow(cos(degRad(Zoom*0.9)),2)*temp[1]);
martin@1: 	y = pow(cos(degRad(Zoom*0.9)),2)*temp[2];
martin@1: 	z = pow(cos(degRad(Zoom*0.9)),2)*temp[3];
martin@0: };
martin@0: 
martin@0: 
martin@0: void Decoder::focusZoom(double &w, double &x, double &y, double &z)
martin@0: {
martin@1:     double temp[4];
martin@1: 	temp[0]=w;
martin@1: 	temp[1]=x;
martin@1: 	temp[2]=y;
martin@1: 	temp[3]=z;
martin@0: 	
martin@1: 	w = ((1/(1+std::abs(sin(degRad(Zoom*0.9)))))*temp[0]) + ((1/sqrt(2.0))*(sin(degRad(Zoom*0.9))/(1+std::abs(sin(degRad(Zoom*0.9))))))* temp[1];
martin@1: 	x = sqrt(2.0)*(sin(degRad(Zoom*0.9))/(1+std::abs(sin(degRad(Zoom*0.9)))))*temp[0] + (1/(1+std::abs(sin(degRad(Zoom*0.9)))))*temp[1];
martin@1: 	y = sqrt((1-std::abs(sin(degRad(Zoom*0.9))))/(1+std::abs(sin(degRad(Zoom*0.9)))))*temp[2];
martin@1: 	z = sqrt((1-std::abs(sin(degRad(Zoom*0.9))))/(1+std::abs(sin(degRad(Zoom*0.9)))))*temp[3];
martin@0: };
martin@0: 
martin@0: 
martin@0: 
martin@0: //Stereo Decoders
martin@0: void Decoder::xyDecode(double &w, double &x, double &y, double &z)
martin@0: {	
martin@0:     outputL = Pattern*sqrt(2.0)*w + (1-Pattern)*(cos(degRad(Width))*x + sin(degRad(Width))*y);
martin@0:     outputR = Pattern*sqrt(2.0)*w + (1-Pattern)*(cos(degRad(Width))*x - sin(degRad(Width))*y);
martin@0: };
martin@0: 
martin@0: 
martin@0: void Decoder::msDecode(double &w, double &x, double &y, double &z)
martin@0: {
martin@0: 	outputL = (cos(degRad(Width))*(Pattern*w*sqrt(2.0) + (1-Pattern)*x)) + (sin(degRad(Width))*y);
martin@0: 	outputR = (cos(degRad(Width))*(Pattern*w*sqrt(2.0) + (1-Pattern)*x)) - (sin(degRad(Width))*y);
martin@0: };
martin@0: 
martin@0: 
martin@0: //Stereo Reverbs
martin@0: void Decoder::rearVerb(double &w, double &x, double &y, double &z)
martin@0: {
martin@0: 	switch (Mode) {
martin@0: 		case 0:
martin@0: 			outputL += (RearVerbPattern*sqrt(2.0)*w + (1-RearVerbPattern)*(cos(degRad(RearVerbWidth))*-x + sin(degRad(RearVerbWidth))*y))*pow(10, RearVerb/20);
martin@0:             outputR += (RearVerbPattern*sqrt(2.0)*w + (1-RearVerbPattern)*(cos(degRad(RearVerbWidth))*-x - sin(degRad(RearVerbWidth))*y))*pow(10, RearVerb/20);
martin@0: 			break;
martin@0: 		case 1:
martin@0:             outputL += ((cos(degRad(RearVerbWidth))*(RearVerbPattern*w*sqrt(2.0) + (1-RearVerbPattern)*-x)) + (sin(degRad(RearVerbWidth))*y))*pow(10, RearVerb/20);
martin@0:             outputR += ((cos(degRad(RearVerbWidth))*(RearVerbPattern*w*sqrt(2.0) + (1-RearVerbPattern)*-x)) - (sin(degRad(RearVerbWidth))*y))*pow(10, RearVerb/20);
martin@0: 			break;
martin@0: 	}
martin@0: };
martin@0: 
martin@0: void Decoder::hiVerb(double &w, double &x, double &y, double &z)
martin@0: {
martin@0: 	switch (Mode) {
martin@0: 		case 0:
martin@0: 			outputL += (HiVerbPattern*sqrt(2.0)*w + (1-HiVerbPattern)*(cos(degRad(HiVerbWidth))*z + sin(degRad(HiVerbWidth))*y))*pow(10, HiVerb/20);
martin@0:             outputR += (HiVerbPattern*sqrt(2.0)*w + (1-HiVerbPattern)*(cos(degRad(HiVerbWidth))*z - sin(degRad(HiVerbWidth))*y))*pow(10, HiVerb/20);
martin@0: 			break;
martin@0: 		case 1:
martin@0:             outputL += ((cos(degRad(HiVerbWidth))*(HiVerbPattern*w*sqrt(2.0) + (1-HiVerbPattern)*z)) + (sin(degRad(HiVerbWidth))*y))*pow(10, HiVerb/20);
martin@0:             outputR += ((cos(degRad(HiVerbWidth))*(HiVerbPattern*w*sqrt(2.0) + (1-HiVerbPattern)*z)) - (sin(degRad(HiVerbWidth))*y))*pow(10, HiVerb/20);
martin@0: 			break;
martin@0: 	}
martin@0: };
martin@0: 
martin@0: 
martin@0: //Surround Decoders
martin@0: void Decoder::xySurDecode(double &w, double &x, double &y, double &z)
martin@0: {	
martin@0:     outputSL = (surPattern*sqrt(2.0)*w + (1-surPattern)*(cos(degRad(surWidth))*-x + sin(degRad(surWidth))*y))*surGain;
martin@0:     outputSR = (surPattern*sqrt(2.0)*w + (1-surPattern)*(cos(degRad(surWidth))*-x - sin(degRad(surWidth))*y))*surGain;
martin@0: };
martin@0: 
martin@0: 
martin@0: void Decoder::msSurDecode(double &w, double &x, double &y, double &z)
martin@0: {
martin@0: 	outputSL = ((cos(degRad(surWidth))*(surPattern*w*sqrt(2.0) + (1-surPattern)*-x)) + (sin(degRad(surWidth))*y))*surGain;
martin@0: 	outputSR = ((cos(degRad(surWidth))*(surPattern*w*sqrt(2.0) + (1-surPattern)*-x)) - (sin(degRad(surWidth))*y))*surGain;
martin@0: };
martin@0: 
martin@0: 
martin@0: void Decoder::centreMic(double &w, double &x)
martin@0: {
martin@1:     outputC = (centrePattern*sqrt(2.0)*w + (1-centrePattern)*x) * centreGain;
martin@0: };
martin@0: 
martin@0: 
martin@0: void Decoder::subSignal(double &w)
martin@0: {
martin@0:     outputS = sqrt(2.0)*w*subGain;
martin@0: };
martin@0: 
martin@0: 
martin@0: void Decoder::filterCoefs(){
martin@0:     int k = tan((M_PI*abs(Fc))/Fs);
martin@0:     double denominator = pow(k, 2) + 2*k + 1;
martin@0:     
martin@0:     //a values
martin@0:     a[0] = 1;
martin@0:     a[1] = (2*(pow(k,2)-1))/denominator;
martin@0:     a[2] = (pow(k, 2) - 2*k + 1)/denominator;
martin@0:     
martin@0:     //b LF value
martin@0:     bLF[0] = pow(k, 2) / denominator;
martin@0:     bLF[1] = 2 * bLF[0];
martin@0:     bLF[2] = bLF[0];
martin@0:     
martin@0:     //b HF values
martin@0:     bHF[0] = 1/denominator;
martin@0:     bHF[1] = -2 * bHF[0];
martin@0:     bHF[2] = bHF[0];
martin@0: };
martin@0: 
martin@0: 
martin@0: void Decoder::filterLF(){
martin@0:     double outLF;
martin@0:     
martin@1:     //LF Filtering
martin@1:     outLF = (double)outputS*bLF[0] + prevInS[0]*bLF[1] + prevInS[1]*bLF[2] + prevOutS[0]*a[1] + prevOutS[1]*a[2];
martin@0:     
martin@1:     //Previous Input and Output Samples
martin@1:     prevOutS[1] = prevOutS[0];
martin@1:     prevOutS[0] = outLF;
martin@1:     prevInS[1] = prevInS[0];
martin@1:     prevInS[0] = (double)outputS;
martin@0:     
martin@1:     //Final subwoofer Output
martin@0:     outputS = outLF;
martin@0: };
martin@0: 
martin@0: 
martin@0: void Decoder::filterHF(double &w, double &x, double &y, double &z){
martin@0:     double outHFw, outHFx, outHFy, outHFz;
martin@0:     
martin@0:     //w Filtering
martin@0:     outHFw = -((double)w*bHF[0] + prevInw[0]*bHF[1] + prevInw[1]*bHF[2] + prevOutw[0]*a[1] + prevOutw[1]*a[2]);
martin@0:     prevOutw[1] = prevOutw[0];
martin@0:     prevOutw[0] = outHFw;
martin@0:     prevInw[1] = prevInw[0];
martin@0:     prevInw[0] = (double)w;
martin@0:     w = outHFw;
martin@0:     
martin@0:     //x Filtering
martin@0:     outHFx = -((double)x*bHF[0] + prevInx[0]*bHF[1] + prevInx[1]*bHF[2] + prevOutx[0]*a[1] + prevOutx[1]*a[2]);
martin@0:     prevOutx[1] = prevOutx[0];
martin@0:     prevOutx[0] = outHFx;
martin@0:     prevInx[1] = prevInx[0];
martin@0:     prevInx[0] = (double)x;
martin@0:     x = outHFx;
martin@0:     
martin@0:     //y Filtering
martin@0:     outHFy = -((double)y*bHF[0] + prevIny[0]*bHF[1] + prevIny[1]*bHF[2] + prevOuty[0]*a[1] + prevOuty[1]*a[2]);
martin@0:     prevOuty[1] = prevOuty[0];
martin@0:     prevOuty[0] = outHFy;
martin@0:     prevIny[1] = prevIny[0];
martin@0:     prevIny[0] = (double)y;
martin@0:     y = outHFy;
martin@0:     
martin@0:     //z Filtering
martin@0:     outHFz = -((double)z*bHF[0] + prevInz[0]*bHF[1] + prevInz[1]*bHF[2] + prevOutz[0]*a[1] + prevOutz[1]*a[2]);
martin@0:     prevOutz[1] = prevOutz[0];
martin@0:     prevOutz[0] = outHFz;
martin@0:     prevInz[1] = prevInz[0];
martin@0:     prevInz[0] = (double)z;
martin@0:     z = outHFz;
martin@0: };
martin@0: 
martin@0: 
martin@0: void Decoder::clearFilter(){
martin@0:     for (int i=0; i<2; i++) {
martin@1:         prevInS[i] = 0;
martin@1:         prevOutS[i] = 0;
martin@0:         prevInw[i] = 0;
martin@0:         prevOutw[i] = 0;
martin@0:         prevInx[i] = 0;
martin@0:         prevOutx[i] = 0;
martin@0:         prevIny[i] = 0;
martin@0:         prevOuty[i] = 0;
martin@0:         prevInz[i] = 0;
martin@0:         prevOutz[i] = 0;
martin@0:     }
martin@0: };