sydney/EqualizerAPO
1
0 Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Improved: Parametric filter calculations (command "Filter") are now fully using double precision. This yields a great improvement in signal-to-noise ratio for practically no performance penalty.

Browse Source 
Fixed: The method BiQuad::gainAt was returning wrong values. As this method was only used for testing purposes, this change is not user-visible.
This commit is contained in:
jthedering committed 2015-08-17 20:05:25 +00:00
1 parent 7ae9879f55
commit d68b958bc8
7 files changed
+157 -116
Download Patch File Download Diff File Expand all files Collapse all files

No files matched your search

filters/BiQuad.cpp
+57 -60
View File
@@ -17,23 +17,20 @@
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/ */
#define _USE_MATH_DEFINES
#include <cmath>
#include <string>
#include "BiQuad.h" #include "BiQuad.h"
using namespace std; using namespace std;
BiQuad::BiQuad(Type type, double dbGain, double freq, double srate, double bandwidthOrQOrS, bool isBandwidth) BiQuad::BiQuad(Type type, double dbGain, double freq, double srate, double bandwidthOrQOrS, bool isBandwidth)
{ {
double A; double A;
if(type == PEAKING || type == LOW_SHELF || type == HIGH_SHELF) if(type == PEAKING || type == LOW_SHELF || type == HIGH_SHELF)
A = pow(10, dbGain / 40); A = pow(10, dbGain / 40);
else else
A = pow(10, dbGain / 20); A = pow(10, dbGain / 20);
double omega = 2 * M_PI * freq / srate; double omega = 2 * M_PI * freq / srate;
double sn = sin(omega); double sn = sin(omega);
double cs = cos(omega); double cs = cos(omega);
double alpha; double alpha;
double beta = -1; double beta = -1;
@@ -52,36 +49,36 @@ BiQuad::BiQuad(Type type, double dbGain, double freq, double srate, double bandw
switch(type) switch(type)
{ {
case LOW_PASS: case LOW_PASS:
b0 = (1 - cs) /2; b0 = (1 - cs) /2;
b1 = 1 - cs; b1 = 1 - cs;
b2 = (1 - cs) /2; b2 = (1 - cs) /2;
a0 = 1 + alpha; a0 = 1 + alpha;
a1 = -2 * cs; a1 = -2 * cs;
a2 = 1 - alpha; a2 = 1 - alpha;
break; break;
case HIGH_PASS: case HIGH_PASS:
b0 = (1 + cs) /2; b0 = (1 + cs) /2;
b1 = -(1 + cs); b1 = -(1 + cs);
b2 = (1 + cs) /2; b2 = (1 + cs) /2;
a0 = 1 + alpha; a0 = 1 + alpha;
a1 = -2 * cs; a1 = -2 * cs;
a2 = 1 - alpha; a2 = 1 - alpha;
break; break;
case BAND_PASS: case BAND_PASS:
b0 = alpha; b0 = alpha;
b1 = 0; b1 = 0;
b2 = -alpha; b2 = -alpha;
a0 = 1 + alpha; a0 = 1 + alpha;
a1 = -2 * cs; a1 = -2 * cs;
a2 = 1 - alpha; a2 = 1 - alpha;
break; break;
case NOTCH: case NOTCH:
b0 = 1; b0 = 1;
b1 = -2 * cs; b1 = -2 * cs;
b2 = 1; b2 = 1;
a0 = 1 + alpha; a0 = 1 + alpha;
a1 = -2 * cs; a1 = -2 * cs;
a2 = 1 - alpha; a2 = 1 - alpha;
break; break;
case ALL_PASS: case ALL_PASS:
b0 = 1 - alpha; b0 = 1 - alpha;
@@ -92,12 +89,12 @@ BiQuad::BiQuad(Type type, double dbGain, double freq, double srate, double bandw
a2 = 1 - alpha; a2 = 1 - alpha;
break; break;
case PEAKING: case PEAKING:
b0 = 1 + (alpha * A); b0 = 1 + (alpha * A);
b1 = -2 * cs; b1 = -2 * cs;
b2 = 1 - (alpha * A); b2 = 1 - (alpha * A);
a0 = 1 + (alpha / A); a0 = 1 + (alpha / A);
a1 = -2 * cs; a1 = -2 * cs;
a2 = 1 - (alpha / A); a2 = 1 - (alpha / A);
break; break;
case LOW_SHELF: case LOW_SHELF:
b0 = A * ((A + 1) - (A - 1) * cs + beta); b0 = A * ((A + 1) - (A - 1) * cs + beta);
@@ -108,20 +105,20 @@ BiQuad::BiQuad(Type type, double dbGain, double freq, double srate, double bandw
a2 = (A + 1) + (A - 1) * cs - beta; a2 = (A + 1) + (A - 1) * cs - beta;
break; break;
case HIGH_SHELF: case HIGH_SHELF:
b0 = A * ((A + 1) + (A - 1) * cs + beta); b0 = A * ((A + 1) + (A - 1) * cs + beta);
b1 = -2 * A * ((A - 1) + (A + 1) * cs); b1 = -2 * A * ((A - 1) + (A + 1) * cs);
b2 = A * ((A + 1) + (A - 1) * cs - beta); b2 = A * ((A + 1) + (A - 1) * cs - beta);
a0 = (A + 1) - (A - 1) * cs + beta; a0 = (A + 1) - (A - 1) * cs + beta;
a1 = 2 * ((A - 1) - (A + 1) * cs); a1 = 2 * ((A - 1) - (A + 1) * cs);
a2 = (A + 1) - (A - 1) * cs - beta; a2 = (A + 1) - (A - 1) * cs - beta;
break; break;
} }
this->a0 = float(b0 / a0); this->a0 = b0 / a0;
this->a[0] = float(b1 / a0); this->a[0] = b1 / a0;
this->a[1] = float(b2 / a0); this->a[1] = b2 / a0;
this->a[2] = float(a1 / a0); this->a[2] = a1 / a0;
this->a[3] = float(a2 / a0); this->a[3] = a2 / a0;
x1 = 0; x1 = 0;
x2 = 0; x2 = 0;
@@ -129,20 +126,20 @@ BiQuad::BiQuad(Type type, double dbGain, double freq, double srate, double bandw
y2 = 0; y2 = 0;
} }
float BiQuad::gainAt(float freq, float srate) double BiQuad::gainAt(double freq, double srate)
{ {
float omega = 2 * (float)M_PI * freq / srate; double omega = 2 * M_PI * freq / srate;
float sn = sin(omega/2.0f); double sn = sin(omega/2.0);
float phi = sn * sn; double phi = sn * sn;
float b0 = this->a0; double b0 = this->a0;
float b1 = this->a[0]; double b1 = this->a[0];
float b2 = this->a[1]; double b2 = this->a[1];
float a0 = 1.0f; double a0 = 1.0;
float a1 = -this->a[2]; double a1 = this->a[2];
float a2 = -this->a[3]; double a2 = this->a[3];
float dbGain = 10*log10( pow(b0+b1+b2, 2) - 4*(b0*b1 + 4*b0*b2 + b1*b2)*phi + 16*b0*b2*phi*phi ) double dbGain = 10*log10( pow(b0+b1+b2, 2) - 4*(b0*b1 + 4*b0*b2 + b1*b2)*phi + 16*b0*b2*phi*phi )
-10*log10( pow(a0+a1+a2, 2) - 4*(a0*a1 + 4*a0*a2 + a1*a2)*phi + 16*a0*a2*phi*phi ); -10*log10( pow(a0+a1+a2, 2) - 4*(a0*a1 + 4*a0*a2 + a1*a2)*phi + 16*a0*a2*phi*phi );
return dbGain; return dbGain;
} }
filters/BiQuad.h
+15 -12
View File
@@ -19,9 +19,12 @@
#pragma once #pragma once
#define _USE_MATH_DEFINES
#include <cmath>
#include <climits>
#include <string> #include <string>
#define IS_DENORMAL(f) (((*(unsigned int *)&(f))&0x7f800000) == 0) #define IS_DENORMAL(d) (abs(d) < DBL_MIN)
class BiQuad class BiQuad
{ {
@@ -38,20 +41,20 @@ public:
void removeDenormals() void removeDenormals()
{ {
if(IS_DENORMAL(x1)) if(IS_DENORMAL(x1))
x1 = 0.0f; x1 = 0.0;
if(IS_DENORMAL(x2)) if(IS_DENORMAL(x2))
x2 = 0.0f; x2 = 0.0;
if(IS_DENORMAL(y1)) if(IS_DENORMAL(y1))
y1 = 0.0f; y1 = 0.0;
if(IS_DENORMAL(y2)) if(IS_DENORMAL(y2))
y2 = 0.0f; y2 = 0.0;
} }
__forceinline __forceinline
float process(float sample) double process(double sample)
{ {
// changed order of additions leads to better pipelining // changed order of additions leads to better pipelining
float result = a0 * sample + a[1] * x2 + a[0] * x1 - a[3] * y2 - a[2] * y1; double result = a0 * sample + a[1] * x2 + a[0] * x1 - a[3] * y2 - a[2] * y1;
x2 = x1; x2 = x1;
x1 = sample; x1 = sample;
@@ -62,12 +65,12 @@ public:
return result; return result;
} }
float gainAt(float freq, float srate); double gainAt(double freq, double srate);
private: private:
__declspec(align(16)) float a[4]; __declspec(align(16)) double a[4];
float a0; double a0;
float x1, x2; double x1, x2;
float y1, y2; double y1, y2;
}; };
filters/BiQuadFilter.cpp
+48 -5
View File
@@ -22,9 +22,11 @@
using namespace std; using namespace std;
BiQuadFilter::BiQuadFilter(BiQuad::Type type, double dbGain, double freq, double bandwidthOrQOrS, bool isBandwidth) BiQuadFilter::BiQuadFilter(BiQuad::Type type, double dbGain, double freq, double bandwidthOrQOrS, bool isBandwidth, bool isCornerFreq)
:type(type), dbGain(dbGain), freq(freq), bandwidthOrQOrS(bandwidthOrQOrS), isBandwidth(isBandwidth) :type(type), dbGain(dbGain), freq(freq), bandwidthOrQOrS(bandwidthOrQOrS), isBandwidth(isBandwidth), isCornerFreq(isCornerFreq)
{ {
channelCount = 0;
biquads = NULL;
} }
BiQuadFilter::~BiQuadFilter() BiQuadFilter::~BiQuadFilter()
@@ -40,10 +42,20 @@ vector<wstring> BiQuadFilter::initialize(float sampleRate, unsigned maxFrameCoun
{ {
this->channelCount = channelNames.size(); this->channelCount = channelNames.size();
biquads = (BiQuad*)MemoryHelper::alloc(channelCount * sizeof(BiQuad)); biquads = (BiQuad*)MemoryHelper::alloc(channelCount * sizeof(BiQuad));
double biquadFreq = freq;
if(isCornerFreq && (type == BiQuad::LOW_SHELF || type == BiQuad::HIGH_SHELF))
{
// frequency adjustment for DCX2496
double centerFreqFactor = pow(10.0, abs(dbGain) / 80.0 / bandwidthOrQOrS);
if(type == BiQuad::LOW_SHELF)
biquadFreq *= centerFreqFactor;
else
biquadFreq /= centerFreqFactor;
}
for(unsigned i=0; i<channelCount; i++) for(unsigned i=0; i<channelCount; i++)
{ {
new (biquads + i) BiQuad(type, dbGain, freq, sampleRate, bandwidthOrQOrS, isBandwidth); new (biquads + i) BiQuad(type, dbGain, biquadFreq, sampleRate, bandwidthOrQOrS, isBandwidth);
} }
return channelNames; return channelNames;
@@ -60,10 +72,41 @@ void BiQuadFilter::process(float** output, float** input, unsigned frameCount)
float* outputChannel = output[i]; float* outputChannel = output[i];
for(unsigned j=0; j<frameCount; j++) for(unsigned j=0; j<frameCount; j++)
outputChannel[j] = bq.process(inputChannel[j]); outputChannel[j] = (float)bq.process(inputChannel[j]);
bq.removeDenormals(); bq.removeDenormals();
biquads[i] = bq; biquads[i] = bq;
} }
} }
#pragma AVRT_CODE_END
BiQuad::Type BiQuadFilter::getType() const
{
return type;
}
double BiQuadFilter::getDbGain() const
{
return dbGain;
}
double BiQuadFilter::getFreq() const
{
return freq;
}
double BiQuadFilter::getBandwidthOrQOrS() const
{
return bandwidthOrQOrS;
}
bool BiQuadFilter::getIsBandwidth() const
{
return isBandwidth;
}
bool BiQuadFilter::getIsCornerFreq() const
{
return isCornerFreq;
}
#pragma AVRT_CODE_END
filters/BiQuadFilter.h
+9 -1
View File
@@ -26,18 +26,26 @@
class BiQuadFilter : public IFilter class BiQuadFilter : public IFilter
{ {
public: public:
BiQuadFilter(BiQuad::Type type, double dbGain, double freq, double bandwidthOrQOrS, bool isBandwidth); BiQuadFilter(BiQuad::Type type, double dbGain, double freq, double bandwidthOrQOrS, bool isBandwidth, bool isCornerFreq);
virtual ~BiQuadFilter(); virtual ~BiQuadFilter();
virtual bool getInPlace() {return true;} virtual bool getInPlace() {return true;}
virtual std::vector<std::wstring> initialize(float sampleRate, unsigned maxFrameCount, std::vector<std::wstring> channelNames); virtual std::vector<std::wstring> initialize(float sampleRate, unsigned maxFrameCount, std::vector<std::wstring> channelNames);
virtual void process(float** output, float** input, unsigned frameCount); virtual void process(float** output, float** input, unsigned frameCount);
BiQuad::Type getType() const;
double getDbGain() const;
double getFreq() const;
double getBandwidthOrQOrS() const;
bool getIsBandwidth() const;
bool getIsCornerFreq() const;
private: private:
BiQuad::Type type; BiQuad::Type type;
double dbGain; double dbGain;
double freq; double freq;
double bandwidthOrQOrS; double bandwidthOrQOrS;
bool isBandwidth; bool isBandwidth;
bool isCornerFreq;
size_t channelCount; size_t channelCount;
BiQuad* biquads; BiQuad* biquads;
filters/BiQuadFilterFactory.cpp
+4 -10
View File
@@ -93,6 +93,7 @@ vector<IFilter*> BiQuadFilterFactory::createFilter(const wstring& configPath, ws
double gain = 0; double gain = 0;
double bandwidthOrQOrS = 0; double bandwidthOrQOrS = 0;
bool isBandwidth = false; bool isBandwidth = false;
bool isCornerFreq = false;
bool error = false; bool error = false;
found = regex_search(parameters, match, regexFreq); found = regex_search(parameters, match, regexFreq);
@@ -194,14 +195,7 @@ vector<IFilter*> BiQuadFilterFactory::createFilter(const wstring& configPath, ws
// Maximum S is 1 for 12 dB // Maximum S is 1 for 12 dB
bandwidthOrQOrS /= 12.0; bandwidthOrQOrS /= 12.0;
if(typeString[typeString.length()-1] != L'C') if(typeString[typeString.length()-1] != L'C')
{ isCornerFreq = true;
// frequency adjustment for DCX2496
double centerFreqFactor = pow(10.0, abs(gain) / 80.0 / bandwidthOrQOrS);
if(type == BiQuad::LOW_SHELF)
freq *= centerFreqFactor;
else
freq /= centerFreqFactor;
}
} }
if(!error) if(!error)
@@ -209,7 +203,7 @@ vector<IFilter*> BiQuadFilterFactory::createFilter(const wstring& configPath, ws
TraceF(L"%s", stream.str().c_str()); TraceF(L"%s", stream.str().c_str());
void* mem = MemoryHelper::alloc(sizeof(BiQuadFilter)); void* mem = MemoryHelper::alloc(sizeof(BiQuadFilter));
filter = new(mem) BiQuadFilter(type, gain, freq, bandwidthOrQOrS, isBandwidth); filter = new(mem) BiQuadFilter(type, gain, freq, bandwidthOrQOrS, isBandwidth, isCornerFreq);
} }
} }
else if(typeString != L"None") else if(typeString != L"None")
@@ -245,4 +239,4 @@ double BiQuadFilterFactory::getFreq(const wstring& freqString)
} }
else else
return -1.0; return -1.0;
} }
filters/IIRFilter.cpp
+19 -23
View File
@@ -22,22 +22,22 @@
using namespace std; using namespace std;
#define IS_DENORMAL(f) (((*(unsigned int *)&(f))&0x7f800000) == 0) #define IS_DENORMAL(d) (abs(d) < DBL_MIN)
IIRFilter::IIRFilter(const vector<double>& coefficients) IIRFilter::IIRFilter(const vector<double>& coefficients)
{ {
order = (unsigned)coefficients.size() / 2 - 1; order = (unsigned)coefficients.size() / 2 - 1;
a = (float*)MemoryHelper::alloc(order * sizeof(float)); a = (double*)MemoryHelper::alloc(order * sizeof(double));
b = (float*)MemoryHelper::alloc(order * sizeof(float)); b = (double*)MemoryHelper::alloc(order * sizeof(double));
x = NULL; x = NULL;
y = NULL; y = NULL;
double a0 = coefficients[order+1]; double a0 = coefficients[order+1];
b0 = float(coefficients[0] / a0); b0 = coefficients[0] / a0;
for(unsigned i=0; i<order; i++) for(unsigned i=0; i<order; i++)
{ {
b[i] = float(coefficients[i+1] / a0); b[i] = coefficients[i+1] / a0;
a[i] = float(-coefficients[i+order+2] / a0); a[i] = -coefficients[i+order+2] / a0;
} }
} }
@@ -61,10 +61,10 @@ vector<wstring> IIRFilter::initialize(float sampleRate, unsigned maxFrameCount,
if(y != NULL) if(y != NULL)
MemoryHelper::free(y); MemoryHelper::free(y);
x = (float*)MemoryHelper::alloc(order * channelCount * sizeof(float)); x = (double*)MemoryHelper::alloc(order * channelCount * sizeof(double));
y = (float*)MemoryHelper::alloc(order * channelCount * sizeof(float)); y = (double*)MemoryHelper::alloc(order * channelCount * sizeof(double));
memset(x, 0, order * channelCount * sizeof(float)); memset(x, 0, order * channelCount * sizeof(double));
memset(y, 0, order * channelCount * sizeof(float)); memset(y, 0, order * channelCount * sizeof(double));
return channelNames; return channelNames;
} }
@@ -78,16 +78,17 @@ void IIRFilter::process(float** output, float** input, unsigned frameCount)
float* outputChannel = output[i]; float* outputChannel = output[i];
unsigned channelOffset = i*order; unsigned channelOffset = i*order;
float* xo = x+channelOffset; double* xo = x+channelOffset;
float* yo = y+channelOffset; double* yo = y+channelOffset;
for(unsigned j=0; j<frameCount; j++) for(unsigned j=0; j<frameCount; j++)
{ {
float sample = inputChannel[j]; double sample = inputChannel[j];
float sum = b0 * sample; double sum = b0 * sample;
for(unsigned k=order-1; k>0; k--) for(unsigned k=order-1; k>0; k--)
{ {
sum += b[k] * xo[k]; sum += b[k] * xo[k];
xo[k] = xo[k-1];
} }
sum += b[0] * xo[0]; sum += b[0] * xo[0];
@@ -95,29 +96,24 @@ void IIRFilter::process(float** output, float** input, unsigned frameCount)
for(unsigned k=order-1; k>0; k--) for(unsigned k=order-1; k>0; k--)
{ {
sum += a[k] * yo[k]; sum += a[k] * yo[k];
yo[k] = yo[k-1];
} }
sum += a[0] * yo[0]; sum += a[0] * yo[0];
for(unsigned k=order-1; k>0; k--)
{
xo[k] = xo[k-1];
yo[k] = yo[k-1];
}
xo[0] = sample; xo[0] = sample;
yo[0] = sum; yo[0] = sum;
outputChannel[j] = sum; outputChannel[j] = (float)sum;
} }
} }
for(unsigned i=0; i<channelCount*order; i++) for(unsigned i=0; i<channelCount*order; i++)
{ {
if(IS_DENORMAL(x[i])) if(IS_DENORMAL(x[i]))
x[i] = 0.0f; x[i] = 0.0;
if(IS_DENORMAL(y[i])) if(IS_DENORMAL(y[i]))
y[i] = 0.0f; y[i] = 0.0;
} }
} }
#pragma AVRT_CODE_END #pragma AVRT_CODE_END
filters/IIRFilter.h
+5 -5
View File
@@ -33,11 +33,11 @@ public:
private: private:
unsigned order; unsigned order;
float b0; double b0;
float* a; double* a;
float* b; double* b;
unsigned channelCount; unsigned channelCount;
float* x; double* x;
float* y; double* y;
}; };
#pragma AVRT_VTABLES_END #pragma AVRT_VTABLES_END