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worked on fir/iir filters

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This commit is contained in:
FrankE
2018-08-06 18:33:17 +02:00
parent 327b580b69
commit d6ac8a72ca
5 changed files with 216 additions and 442 deletions
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12
math/dsp/fir/Complex.h
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@@ -181,8 +181,16 @@ private:
}
// https://dsp.stackexchange.com/questions/4693/fir-filter-gain
static void normalizeAC(std::vector<std::complex<float>>& kernel, const float freq) {
throw std::runtime_error("TODO");
static void normalizeAC(std::vector<std::complex<float>>& kernel, const float freq, const float sRate) {
// std::complex<float> sum;
// for (size_t i = 0; i < kernel.size(); ++i) {
// const float t = (float) i / sRate;
// const float v = std::sin(t*freq);
// }
// for (auto f : kernel) {sum += f * sin;}
// for (auto& f : kernel) {f /= sum;}
throw std::runtime_error("todo");
}
/** build a lowpass filter kernel */

15
math/dsp/fir/Real.h
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@@ -35,6 +35,16 @@ namespace FIR {
this->kernel = kernel;
}
const Kernel& getKernel() const {
return this->kernel;
}
void prefill(float val) {
for (size_t i = 0; i < (kernel.size()-1)/2; ++i) {
append(val);
}
}
/** filter the given incoming real data */
DataVec append(const DataVec& newData) {
// append to local buffer (as we need some history)
@@ -56,10 +66,11 @@ namespace FIR {
DataVec processLocalBuffer() {
// sanity check
Assert::isNot0(kernel.size(), "FIRComplex:: kernel not yet configured!");
Assert::isNot0(kernel.size(), "FIR::Real::Filter kernel not yet configured!");
// number of processable elements (due to filter size)
const int processable = data.size() - kernel.size() + 1 - kernel.size()/2;
//const int processable = data.size() - kernel.size() + 1 - kernel.size()/2;
const int processable = data.size() - kernel.size();
// nothing to-do?
if (processable <= 0) {return DataVec();}

274
math/dsp/iir/BiQuad.h
View File

@@ -46,6 +46,14 @@ namespace IIR {
}
float getA0() {return 1;}
float getA1() {return a1a0;}
float getA2() {return a2a0;}
float getB0() {return b0a0;}
float getB1() {return b1a0;}
float getB2() {return b2a0;}
void preFill(const Scalar s) {
for (int i = 0; i < 100; ++i) {
filter(s);
@@ -67,12 +75,14 @@ namespace IIR {
}
/** configure the filter as low-pass. freqFact between ]0;0.5[ */
void setLowPass( double freqFact, const float octaves ) {
//void setLowPass( double freqFact, const float octaves ) {
void setLowPass( double freqFact, const float Q ) {
sanityCheck(freqFact);
double w0 = 2.0 * M_PI * freqFact;
double alpha = sin(w0)*sinh( log(2)/2 * octaves * w0/sin(w0) );
//double alpha = sin(w0)*sinh( log(2)/2 * octaves * w0/sin(w0) );
double alpha = sin(w0)/(2*Q);
double b0 = (1.0 - cos(w0))/2.0;
double b1 = 1.0 - cos(w0);
@@ -94,46 +104,48 @@ namespace IIR {
//http://dspwiki.com/index.php?title=Lowpass_Resonant_Biquad_Filter
//http://www.opensource.apple.com/source/WebCore/WebCore-7536.26.14/platform/audio/Biquad.cpp
/**
* configure as low-pass filter with resonance
* @param freqFact the frequency factor between ]0;0.5[
* @param res
*/
void setLowPassResonance( double freqFact, float res ) {
// //http://dspwiki.com/index.php?title=Lowpass_Resonant_Biquad_Filter
// //http://www.opensource.apple.com/source/WebCore/WebCore-7536.26.14/platform/audio/Biquad.cpp
// /**
// * configure as low-pass filter with resonance
// * @param freqFact the frequency factor between ]0;0.5[
// * @param res
// */
// void setLowPassResonance( double freqFact, float res ) {
sanityCheck(freqFact);
// sanityCheck(freqFact);
res *= 10;
// res *= 10;
double g = pow(10.0, 0.05 * res);
double d = sqrt((4 - sqrt(16 - 16 / (g * g))) / 2);
// double g = pow(10.0, 0.05 * res);
// double d = sqrt((4 - sqrt(16 - 16 / (g * g))) / 2);
double theta = M_PI * freqFact;
double sn = 0.5 * d * sin(theta);
double beta = 0.5 * (1 - sn) / (1 + sn);
double gamma = (0.5 + beta) * cos(theta);
double alpha = 0.25 * (0.5 + beta - gamma);
// double theta = M_PI * freqFact;
// double sn = 0.5 * d * sin(theta);
// double beta = 0.5 * (1 - sn) / (1 + sn);
// double gamma = (0.5 + beta) * cos(theta);
// double alpha = 0.25 * (0.5 + beta - gamma);
double a0 = 1.0;
double b0 = 2.0 * alpha;
double b1 = 2.0 * 2.0 * alpha;
double b2 = 2.0 * alpha;
double a1 = 2.0 * -gamma;
double a2 = 2.0 * beta;
// double a0 = 1.0;
// double b0 = 2.0 * alpha;
// double b1 = 2.0 * 2.0 * alpha;
// double b2 = 2.0 * alpha;
// double a1 = 2.0 * -gamma;
// double a2 = 2.0 * beta;
setValues(a0, a1, a2, b0, b1, b2);
// setValues(a0, a1, a2, b0, b1, b2);
}
// }
/** configure the filter as high-pass. freqFact between ]0;0.5[ */
void setHighPass( double freqFact, const float octaves ) {
//void setHighPass( double freqFact, const float octaves ) {
void setHighPass( double freqFact, const float Q ) {
sanityCheck(freqFact);
double w0 = 2.0 * M_PI * freqFact;
double alpha = sin(w0)*sinh( log(2)/2 * octaves * w0/sin(w0) );
//double alpha = sin(w0)*sinh( log(2)/2 * octaves * w0/sin(w0) );
double alpha = sin(w0)/(2*Q);
double b0 = (1.0 + cos(w0))/2.0;
double b1 = -(1.0 + cos(w0));
@@ -153,17 +165,21 @@ namespace IIR {
}
/** configure the filter as band-pass. freqFact between ]0;0.5[ */
void setBandPass( double freqFact, const float octaves ) {
//void setBandPass( double freqFact, const float octaves ) {
void setBandPass( double freqFact, const float Q ) {
sanityCheck(freqFact);
//double w0 = 2 * K_PI * / 2 / freqFact;
double w0 = 2.0 * M_PI * freqFact;
double alpha = sin(w0)*sinh( log(2)/2 * octaves * w0/sin(w0) );
//double alpha = sin(w0)*sinh( log(2)/2 * octaves * w0/sin(w0) );
double alpha = sin(w0)/(2*Q);
double b0 = sin(w0)/2.0;
// constant 0dB peak gain
double b0 = alpha;
double b1 = 0.0;
double b2 = -sin(w0)/2.0;
double b2 = -alpha;
double a0 = 1.0 + alpha;
double a1 = -2.0*cos(w0);
double a2 = 1.0 - alpha;
@@ -179,108 +195,112 @@ namespace IIR {
}
/** configure the filter as all-pass. freqFact between ]0;0.5[ */
void setAllPass( double freqFact, const float octaves ) {
// /** configure the filter as all-pass. freqFact between ]0;0.5[ */
// void setAllPass( double freqFact, const float octaves ) {
sanityCheck(freqFact);
// sanityCheck(freqFact);
double w0 = 2.0 * M_PI * freqFact;
double alpha = sin(w0)*sinh( log(2)/2 * octaves * w0/sin(w0) );
// double w0 = 2.0 * M_PI * freqFact;
// double alpha = sin(w0)*sinh( log(2)/2 * octaves * w0/sin(w0) );
double b0 = 1 - alpha;
double b1 = -2*cos(w0);
double b2 = 1 + alpha;
double a0 = 1 + alpha;
double a1 = -2*cos(w0);
double a2 = 1 - alpha;
// double b0 = 1 - alpha;
// double b1 = -2*cos(w0);
// double b2 = 1 + alpha;
// double a0 = 1 + alpha;
// double a1 = -2*cos(w0);
// double a2 = 1 - alpha;
setValues(a0, a1, a2, b0, b1, b2);
// setValues(a0, a1, a2, b0, b1, b2);
}
// }
/** configure the filter as all-pass */
void setAllPass( const float freq, const float octaves, const float sRate ) {
double freqFact = double(freq) / double(sRate);
setAllPass(freqFact, octaves);
}
/** configure as notch filter. freqFact between ]0;0.5[ */
void setNotch( double freqFact, const float octaves ) {
sanityCheck(freqFact);
double w0 = 2.0 * M_PI * freqFact;
double alpha = sin(w0)*sinh( log(2)/2 * octaves * w0/sin(w0) );
double b0 = 1.0;
double b1 = -2.0*cos(w0);
double b2 = 1.0;
double a0 = 1.0 + alpha;
double a1 = -2.0*cos(w0);
double a2 = 1.0 - alpha;
setValues(a0, a1, a2, b0, b1, b2);
}
/** configure as notch filter */
void setNotch( const float freq, const float octaves, const float sRate ) {
double freqFact = double(freq) / double(sRate);
setNotch(freqFact, octaves);
}
/** configure the filter as low-shelf. increase all aplitudes below freq? freqFact between ]0;0.5[ */
void setLowShelf( double freqFact, const float octaves, const float gain ) {
sanityCheck(freqFact);
double A = sqrt( pow(10, (gain/20.0)) );
double w0 = 2.0 * M_PI * freqFact;
double alpha = sin(w0)*sinh( log(2)/2 * octaves * w0/sin(w0) );
double b0 = A*( (A+1.0) - (A-1.0)*cos(w0) + 2.0*sqrt(A)*alpha );
double b1 = 2.0*A*( (A-1.0) - (A+1.0)*cos(w0) );
double b2 = A*( (A+1.0) - (A-1.0)*cos(w0) - 2.0*sqrt(A)*alpha );
double a0 = (A+1.0) + (A-1.0)*cos(w0) + 2.0*sqrt(A)*alpha;
double a1 = -2.0*( (A-1.0) + (A+1.0)*cos(w0) );
double a2 = (A+1.0) + (A-1.0)*cos(w0) - 2.0*sqrt(A)*alpha;
setValues(a0, a1, a2, b0, b1, b2);
}
/** configure the filter as low-shelf. increase all aplitudes below freq? */
void setLowShelf( const float freq, const float octaves, const float gain, const float sRate ) {
double freqFact = double(freq) / double(sRate);
setLowShelf(freqFact, octaves, gain);
}
/** configure the filter as high-shelf. increase all amplitues above freq? freqFact between ]0;0.5[ */
void setHighShelf( double freqFact, const float octaves, const float gain ) {
sanityCheck(freqFact);
double A = sqrt( pow(10, (gain/20.0)) );
double w0 = 2.0 * M_PI * freqFact;
double alpha = sin(w0)*sinh( log(2)/2 * octaves * w0/sin(w0) );
double b0 = A*( (A+1.0) + (A-1.0)*cos(w0) + 2.0*sqrt(A)*alpha );
double b1 = -2.0*A*( (A-1.0) + (A+1.0)*cos(w0) );
double b2 = A*( (A+1.0) + (A-1.0)*cos(w0) - 2.0*sqrt(A)*alpha );
double a0 = (A+1.0) - (A-1.0)*cos(w0) + 2.0*sqrt(A)*alpha;
double a1 = 2.0*( (A-1.0) - (A+1.0)*cos(w0) );
double a2 = (A+1.0) - (A-1.0)*cos(w0) - 2.0*sqrt(A)*alpha;
setValues(a0, a1, a2, b0, b1, b2);
}
// /** configure the filter as all-pass */
// void setAllPass( const float freq, const float octaves, const float sRate ) {
// double freqFact = double(freq) / double(sRate);
// setAllPass(freqFact, octaves);
// }
/** configure the filter as high-shelf. increase all amplitues above freq? */
void setHighShelf( const float freq, const float octaves, const float gain, const float sRate ) {
double freqFact = double(freq) / double(sRate);
setHighShelf(freqFact, octaves, gain);
}
// /** configure as notch filter. freqFact between ]0;0.5[ */
// //void setNotch( double freqFact, const float octaves ) {
// void setNotch( double freqFact, const float Q ) {
// sanityCheck(freqFact);
// double w0 = 2.0 * M_PI * freqFact;
// double alpha = sin(w0)*sinh( log(2)/2 * octaves * w0/sin(w0) );
// double b0 = 1.0;
// double b1 = -2.0*cos(w0);
// double b2 = 1.0;
// double a0 = 1.0 + alpha;
// double a1 = -2.0*cos(w0);
// double a2 = 1.0 - alpha;
// setValues(a0, a1, a2, b0, b1, b2);
// }
// /** configure as notch filter */
// void setNotch( const float freq, const float octaves, const float sRate ) {
// double freqFact = double(freq) / double(sRate);
// setNotch(freqFact, octaves);
// }
// /** configure the filter as low-shelf. increase all aplitudes below freq? freqFact between ]0;0.5[ */
// void setLowShelf( double freqFact, const float octaves, const float gain ) {
// sanityCheck(freqFact);
// double A = sqrt( pow(10, (gain/20.0)) );
// double w0 = 2.0 * M_PI * freqFact;
// double alpha = sin(w0)*sinh( log(2)/2 * octaves * w0/sin(w0) );
// double b0 = A*( (A+1.0) - (A-1.0)*cos(w0) + 2.0*sqrt(A)*alpha );
// double b1 = 2.0*A*( (A-1.0) - (A+1.0)*cos(w0) );
// double b2 = A*( (A+1.0) - (A-1.0)*cos(w0) - 2.0*sqrt(A)*alpha );
// double a0 = (A+1.0) + (A-1.0)*cos(w0) + 2.0*sqrt(A)*alpha;
// double a1 = -2.0*( (A-1.0) + (A+1.0)*cos(w0) );
// double a2 = (A+1.0) + (A-1.0)*cos(w0) - 2.0*sqrt(A)*alpha;
// setValues(a0, a1, a2, b0, b1, b2);
// }
// /** configure the filter as low-shelf. increase all aplitudes below freq? */
// void setLowShelf( const float freq, const float octaves, const float gain, const float sRate ) {
// double freqFact = double(freq) / double(sRate);
// setLowShelf(freqFact, octaves, gain);
// }
// /** configure the filter as high-shelf. increase all amplitues above freq? freqFact between ]0;0.5[ */
// void setHighShelf( double freqFact, const float octaves, const float gain ) {
// sanityCheck(freqFact);
// double A = sqrt( pow(10, (gain/20.0)) );
// double w0 = 2.0 * M_PI * freqFact;
// double alpha = sin(w0)*sinh( log(2)/2 * octaves * w0/sin(w0) );
// double b0 = A*( (A+1.0) + (A-1.0)*cos(w0) + 2.0*sqrt(A)*alpha );
// double b1 = -2.0*A*( (A-1.0) + (A+1.0)*cos(w0) );
// double b2 = A*( (A+1.0) + (A-1.0)*cos(w0) - 2.0*sqrt(A)*alpha );
// double a0 = (A+1.0) - (A-1.0)*cos(w0) + 2.0*sqrt(A)*alpha;
// double a1 = 2.0*( (A-1.0) - (A+1.0)*cos(w0) );
// double a2 = (A+1.0) - (A-1.0)*cos(w0) - 2.0*sqrt(A)*alpha;
// setValues(a0, a1, a2, b0, b1, b2);
// }
// /** configure the filter as high-shelf. increase all amplitues above freq? */
// void setHighShelf( const float freq, const float octaves, const float gain, const float sRate ) {
// double freqFact = double(freq) / double(sRate);
// setHighShelf(freqFact, octaves, gain);
// }
protected: