Nsound::Filter Class Reference

#include <Nsound/Filter.h>

Inheritance diagram for Nsound::Filter:
Inheritance graph
[legend]

List of all members.

Public Member Functions

 Filter (const float64 &sample_rate)
virtual ~Filter ()
AudioStream filter (const AudioStream &x)
AudioStream filter (const AudioStream &x, const float64 &frequency)
AudioStream filter (const AudioStream &x, const Buffer &frequencies)
Buffer filter (const Buffer &x)
Buffer filter (const Buffer &x, const float64 &frequency)
Buffer filter (const Buffer &x, const Buffer &frequencies)
virtual float64 filter (const float64 &x)=0
virtual float64 filter (const float64 &x, const float64 &frequency)=0
Buffer getFrequencyAxis (const uint32 n_fft=8192)
Buffer getFrequencyResponse (const uint32 n_fft=8192)
Buffer getImpulseResponse (const uint32 n_samples=8192)
virtual uint32 getKernelSize () const
Buffer getPhaseResponse ()
float64 getSampleRate () const
void plot (boolean show_phase=false)
virtual void reset ()=0

Protected Attributes

float64 sample_rate_
float64 two_pi_over_sample_rate_
uint32 kernel_size_

Detailed Description

Base class for IIR Filters, defines the interface.

Definition at line 49 of file Filter.h.

Constructor & Destructor Documentation

Filter::Filter ( const float64 &  sample_rate  ) 

Definition at line 42 of file Filter.cc.

00044     :
00045     sample_rate_(sample_rate),
00046     two_pi_over_sample_rate_(2.0 * M_PI / sample_rate),
00047     kernel_size_(0)
00048 {
}

virtual Nsound::Filter::~Filter (  )  [inline, virtual]

Definition at line 58 of file Filter.h.

00058 {};

Member Function Documentation

AudioStream Filter::filter ( const AudioStream &  x  ) 

Reimplemented in Nsound::FilterAllPass, Nsound::FilterBandPassFIR, Nsound::FilterBandPassIIR, Nsound::FilterBandPassVocoder, Nsound::FilterBandRejectFIR, Nsound::FilterBandRejectIIR, Nsound::FilterCombLowPassFeedback, Nsound::FilterDelay, Nsound::FilterFlanger, Nsound::FilterHighPassFIR, Nsound::FilterHighPassIIR, Nsound::FilterIIR, Nsound::FilterLeastSquaresFIR, Nsound::FilterLowPassFIR, Nsound::FilterLowPassIIR, Nsound::FilterMovingAverage, Nsound::FilterParametricEqualizer, Nsound::FilterPhaser, Nsound::FilterSlinky, Nsound::FilterStageIIR, and Nsound::FilterTone.

Definition at line 53 of file Filter.cc.

References Nsound::AudioStream::getNChannels(), Nsound::AudioStream::getSampleRate(), and reset().

Referenced by filter(), and getImpulseResponse().

00054 {
00055     reset();
00056 
00057     uint32 n_channels = x.getNChannels();
00058 
00059     AudioStream y(x.getSampleRate(), n_channels);
00060 
00061     for(uint32 channel = 0; channel < n_channels; ++channel)
00062     {
00063         y[channel] = filter(x[channel]);
00064     }
00065 
00066     return y;
00067 }

AudioStream Filter::filter ( const AudioStream &  x,
const float64 &  frequency 
)

Reimplemented in Nsound::FilterAllPass, Nsound::FilterBandPassIIR, Nsound::FilterBandRejectIIR, Nsound::FilterDelay, Nsound::FilterFlanger, Nsound::FilterHighPassFIR, Nsound::FilterHighPassIIR, Nsound::FilterLeastSquaresFIR, Nsound::FilterLowPassFIR, Nsound::FilterLowPassIIR, and Nsound::FilterStageIIR.

Definition at line 72 of file Filter.cc.

References filter(), Nsound::AudioStream::getNChannels(), Nsound::AudioStream::getSampleRate(), and reset().

00073 {
00074     reset();
00075 
00076     uint32 n_channels = x.getNChannels();
00077 
00078     AudioStream y(x.getSampleRate(), n_channels);
00079 
00080     for(uint32 channel = 0; channel < n_channels; ++channel)
00081     {
00082         y[channel] = filter(x[channel], frequency);
00083     }
00084 
00085     return y;
00086 }

AudioStream Filter::filter ( const AudioStream &  x,
const Buffer &  frequencies 
)

Reimplemented in Nsound::FilterAllPass, Nsound::FilterBandPassIIR, Nsound::FilterBandPassVocoder, Nsound::FilterBandRejectIIR, Nsound::FilterCombLowPassFeedback, Nsound::FilterDelay, Nsound::FilterHighPassFIR, Nsound::FilterHighPassIIR, Nsound::FilterIIR, Nsound::FilterLeastSquaresFIR, Nsound::FilterLowPassFIR, Nsound::FilterLowPassIIR, Nsound::FilterMovingAverage, Nsound::FilterParametricEqualizer, Nsound::FilterSlinky, Nsound::FilterStageIIR, and Nsound::FilterTone.

Definition at line 91 of file Filter.cc.

References filter(), Nsound::AudioStream::getNChannels(), Nsound::AudioStream::getSampleRate(), and reset().

00092 {
00093     reset();
00094 
00095     uint32 n_channels = x.getNChannels();
00096 
00097     AudioStream y(x.getSampleRate(), n_channels);
00098 
00099     for(uint32 channel = 0; channel < n_channels; ++channel)
00100     {
00101         y[channel] = filter(x[channel], frequency);
00102     }
00103 
00104     return y;
00105 }

Buffer Filter::filter ( const Buffer &  x  ) 

Reimplemented in Nsound::FilterAllPass, Nsound::FilterBandPassFIR, Nsound::FilterBandPassIIR, Nsound::FilterBandPassVocoder, Nsound::FilterBandRejectFIR, Nsound::FilterBandRejectIIR, Nsound::FilterCombLowPassFeedback, Nsound::FilterDelay, Nsound::FilterFlanger, Nsound::FilterHighPassFIR, Nsound::FilterHighPassIIR, Nsound::FilterIIR, Nsound::FilterLeastSquaresFIR, Nsound::FilterLowPassFIR, Nsound::FilterLowPassIIR, Nsound::FilterMovingAverage, Nsound::FilterParametricEqualizer, Nsound::FilterPhaser, Nsound::FilterSlinky, Nsound::FilterStageIIR, and Nsound::FilterTone.

Definition at line 110 of file Filter.cc.

References filter(), Nsound::Buffer::getLength(), and reset().

00111 {
00112     reset();
00113 
00114     Buffer y(x.getLength());
00115 
00116     uint32 x_samples = x.getLength();
00117 
00118     for(uint32 i = 0; i < x_samples; ++i)
00119     {
00120         y << filter(x[i]);
00121     }
00122 
00123     return y;
00124 }

Buffer Filter::filter ( const Buffer &  x,
const float64 &  frequency 
)

Reimplemented in Nsound::FilterAllPass, Nsound::FilterBandPassIIR, Nsound::FilterBandRejectIIR, Nsound::FilterDelay, Nsound::FilterFlanger, Nsound::FilterHighPassFIR, Nsound::FilterHighPassIIR, Nsound::FilterLeastSquaresFIR, Nsound::FilterLowPassFIR, Nsound::FilterLowPassIIR, and Nsound::FilterStageIIR.

Definition at line 129 of file Filter.cc.

References Nsound::Buffer::begin(), Nsound::Buffer::end(), filter(), Nsound::Buffer::getLength(), and reset().

00130 {
00131     reset();
00132 
00133     Buffer::const_iterator itor = x.begin();
00134     Buffer::const_iterator end = x.end();
00135 
00136     Buffer y(x.getLength());
00137 
00138     while(itor != end)
00139     {
00140         y << filter(*itor, frequency);
00141 
00142         ++itor;
00143     }
00144 
00145     return y;
00146 }

Buffer Filter::filter ( const Buffer &  x,
const Buffer &  frequencies 
)

Reimplemented in Nsound::FilterAllPass, Nsound::FilterBandPassIIR, Nsound::FilterBandPassVocoder, Nsound::FilterBandRejectIIR, Nsound::FilterCombLowPassFeedback, Nsound::FilterDelay, Nsound::FilterHighPassFIR, Nsound::FilterHighPassIIR, Nsound::FilterIIR, Nsound::FilterLeastSquaresFIR, Nsound::FilterLowPassFIR, Nsound::FilterLowPassIIR, Nsound::FilterMovingAverage, Nsound::FilterParametricEqualizer, Nsound::FilterSlinky, Nsound::FilterStageIIR, and Nsound::FilterTone.

Definition at line 151 of file Filter.cc.

References Nsound::Buffer::begin(), Nsound::Buffer::cbegin(), Nsound::Buffer::end(), filter(), Nsound::Buffer::getLength(), and reset().

00152 {
00153     reset();
00154 
00155     Buffer::circular_iterator freq = frequencies.cbegin();
00156 
00157     Buffer::const_iterator itor = x.begin();
00158     Buffer::const_iterator end = x.end();
00159 
00160     Buffer y(x.getLength());
00161 
00162     while(itor != end)
00163     {
00164         y << filter(*itor, *freq);
00165 
00166         ++itor;
00167         ++freq;
00168     }
00169 
00170     return y;
00171 }

virtual float64 Nsound::Filter::filter ( const float64 &  x  )  [pure virtual]

Implemented in Nsound::FilterAllPass, Nsound::FilterBandPassFIR, Nsound::FilterBandPassIIR, Nsound::FilterBandPassVocoder, Nsound::FilterBandRejectFIR, Nsound::FilterBandRejectIIR, Nsound::FilterCombLowPassFeedback, Nsound::FilterDelay, Nsound::FilterFlanger, Nsound::FilterHighPassFIR, Nsound::FilterHighPassIIR, Nsound::FilterIIR, Nsound::FilterLeastSquaresFIR, Nsound::FilterLowPassFIR, Nsound::FilterLowPassIIR, Nsound::FilterMovingAverage, Nsound::FilterParametricEqualizer, Nsound::FilterPhaser, Nsound::FilterSlinky, Nsound::FilterStageIIR, and Nsound::FilterTone.

virtual float64 Nsound::Filter::filter ( const float64 &  x,
const float64 &  frequency 
) [pure virtual]

Implemented in Nsound::FilterAllPass, Nsound::FilterBandPassFIR, Nsound::FilterBandPassIIR, Nsound::FilterBandPassVocoder, Nsound::FilterBandRejectFIR, Nsound::FilterBandRejectIIR, Nsound::FilterCombLowPassFeedback, Nsound::FilterDelay, Nsound::FilterFlanger, Nsound::FilterHighPassFIR, Nsound::FilterHighPassIIR, Nsound::FilterIIR, Nsound::FilterLeastSquaresFIR, Nsound::FilterLowPassFIR, Nsound::FilterLowPassIIR, Nsound::FilterMovingAverage, Nsound::FilterParametricEqualizer, Nsound::FilterPhaser, Nsound::FilterSlinky, Nsound::FilterStageIIR, and Nsound::FilterTone.

Buffer Filter::getFrequencyAxis ( const uint32  n_fft = 8192  ) 

Definition at line 176 of file Filter.cc.

References Nsound::FFTransform::roundUp2(), and sample_rate_.

Referenced by main(), plot(), and Nsound::FilterIIR::savePlot().

00177 {
00178     uint32 fft_chunk_size = FFTransform::roundUp2(
00179         static_cast<int32>(n_fft));
00180 
00181     uint32 n_samples = fft_chunk_size / 2 + 1;
00182 
00183     float64 f_step = (1.0 / (static_cast<float64>(fft_chunk_size) / 2.0))
00184                    * (sample_rate_ / 2.0);
00185 
00186     Buffer f_axis;
00187 
00188     float64 f = 0.0;
00189 
00190     for(uint32 i = 0; i < n_samples; ++i)
00191     {
00192         f_axis << f;
00193         f += f_step;
00194     }
00195 
00196     return f_axis;
00197 };

Buffer Filter::getFrequencyResponse ( const uint32  n_fft = 8192  ) 

Definition at line 202 of file Filter.cc.

References Nsound::FFTransform::fft(), getImpulseResponse(), and sample_rate_.

Referenced by Nsound::FilterBandPassIIR::FilterBandPassIIR(), FilterLeastSquaresFIR_UnitTest(), Nsound::FilterIIR::getRMS(), main(), plot(), and Nsound::FilterIIR::savePlot().

00203 {
00204     FFTransform fft(sample_rate_);
00205 
00206 //~    fft.setWindow(HANNING);
00207 
00208     FFTChunkVector vec;
00209 
00210     vec = fft.fft(getImpulseResponse(), n_fft);
00211 
00212     return vec[0].getMagnitude();
00213 }

Buffer Filter::getImpulseResponse ( const uint32  n_samples = 8192  ) 

Reimplemented in Nsound::FilterIIR.

Definition at line 218 of file Filter.cc.

References filter(), and reset().

Referenced by getFrequencyResponse(), and getPhaseResponse().

00219 {
00220     reset();
00221 
00222     Buffer response(n_samples);
00223 
00224     response << filter(1.0);
00225 
00226     for(uint32 i = 1; i < n_samples; ++i)
00227     {
00228         response << filter(0.0);
00229     }
00230 
00231     reset();
00232 
00233     return response;
00234 }

virtual uint32 Nsound::Filter::getKernelSize (  )  const [inline, virtual]

Reimplemented in Nsound::FilterIIR, and Nsound::FilterTone.

Definition at line 109 of file Filter.h.

References kernel_size_.

Referenced by Nsound::FilterBandPassIIR::FilterBandPassIIR(), Nsound::FilterBandRejectIIR::plot(), Nsound::FilterBandPassIIR::plot(), and Nsound::FilterBandPassFIR::plot().

00109 {return kernel_size_;};

Buffer Filter::getPhaseResponse (  ) 

Definition at line 239 of file Filter.cc.

References Nsound::FFTransform::fft(), getImpulseResponse(), Nsound::Buffer::getLength(), sample_rate_, and Nsound::Buffer::subbuffer().

Referenced by plot().

00240 {
00241     uint32 n_samples = static_cast<uint32>(sample_rate_ * 2);
00242 
00243     FFTransform fft(n_samples);
00244 
00245     FFTChunkVector vec;
00246 
00247     vec = fft.fft(getImpulseResponse(), n_samples);
00248 
00249     Buffer phase = vec[0].getPhase();
00250 
00251     return phase.subbuffer(0, phase.getLength() / 2 + 1);
00252 }

float64 Nsound::Filter::getSampleRate (  )  const [inline]

Definition at line 117 of file Filter.h.

References sample_rate_.

00117 { return sample_rate_; };

void Filter::plot ( boolean  show_phase = false  ) 

Definition at line 257 of file Filter.cc.

References Nsound::Plotter::figure(), Nsound::Buffer::getdB(), getFrequencyAxis(), getFrequencyResponse(), Nsound::Buffer::getMax(), getPhaseResponse(), Nsound::Plotter::plot(), Nsound::Plotter::subplot(), Nsound::Plotter::xlabel(), Nsound::Plotter::ylabel(), and Nsound::Plotter::ylim().

Referenced by main().

00258 {
00259     Buffer x = getFrequencyAxis();
00260     Buffer fr = getFrequencyResponse().getdB();
00261 
00262     Plotter pylab;
00263 
00264     pylab.figure();
00265 
00266     int subplot_int = 111;
00267 
00268     if(show_phase)
00269     {
00270         subplot_int = 211;
00271     }
00272 
00273     pylab.subplot(subplot_int);
00274 
00275     // Frequency response
00276     pylab.plot(x,fr, "blue");
00277 
00278     pylab.xlabel("Frequency (Hz)");
00279     pylab.ylabel("Frequency Response (dB)");
00280 
00281     // Phase response
00282     if(show_phase)
00283     {
00284         pylab.subplot(subplot_int + 1);
00285 
00286         Buffer pr = getPhaseResponse().getdB();
00287 
00288         pylab.plot(x,pr);
00289 
00290         pylab.xlabel("Frequency (Hz)");
00291         pylab.ylabel("Phase Response (dB)");
00292     }
00293 
00294     float64 ymax = fr.getMax();
00295     float64 height = ymax - -60.0;
00296 
00297     pylab.ylim(-60.0, ymax + 0.05 * height);
00298 
00299 }

virtual void Nsound::Filter::reset (  )  [pure virtual]

Implemented in Nsound::FilterAllPass, Nsound::FilterBandPassFIR, Nsound::FilterBandPassIIR, Nsound::FilterBandPassVocoder, Nsound::FilterBandRejectFIR, Nsound::FilterBandRejectIIR, Nsound::FilterCombLowPassFeedback, Nsound::FilterDelay, Nsound::FilterFlanger, Nsound::FilterHighPassFIR, Nsound::FilterHighPassIIR, Nsound::FilterIIR, Nsound::FilterLeastSquaresFIR, Nsound::FilterLowPassFIR, Nsound::FilterLowPassIIR, Nsound::FilterMovingAverage, Nsound::FilterParametricEqualizer, Nsound::FilterPhaser, Nsound::FilterSlinky, Nsound::FilterStageIIR, and Nsound::FilterTone.

Referenced by filter(), and getImpulseResponse().

Member Data Documentation

float64 Nsound::Filter::sample_rate_ [protected]

Definition at line 131 of file Filter.h.

Referenced by Nsound::FilterPhaser::filter(), Nsound::FilterDelay::filter(), Nsound::FilterCombLowPassFeedback::filter(), Nsound::FilterAllPass::FilterAllPass(), Nsound::FilterCombLowPassFeedback::FilterCombLowPassFeedback(), Nsound::FilterDelay::FilterDelay(), Nsound::FilterFlanger::FilterFlanger(), Nsound::FilterPhaser::FilterPhaser(), Nsound::FilterSlinky::FilterSlinky(), getFrequencyAxis(), getFrequencyResponse(), getPhaseResponse(), getSampleRate(), Nsound::FilterStageIIR::makeIIRKernelHelper(), Nsound::FilterStageIIR::makeKernel(), Nsound::FilterParametricEqualizer::makeKernel(), Nsound::FilterLeastSquaresFIR::makeKernel(), Nsound::FilterHighPassFIR::makeKernel(), Nsound::FilterBandPassVocoder::makeKernel(), Nsound::FilterPhaser::operator=(), Nsound::FilterLeastSquaresFIR::operator=(), Nsound::FilterIIR::operator=(), Nsound::FilterFlanger::operator=(), Nsound::FilterTone::plot(), Nsound::FilterPhaser::plot(), Nsound::FilterParametricEqualizer::plot(), Nsound::FilterLowPassIIR::plot(), Nsound::FilterLowPassFIR::plot(), Nsound::FilterLeastSquaresFIR::plot(), Nsound::FilterHighPassIIR::plot(), Nsound::FilterHighPassFIR::plot(), Nsound::FilterFlanger::plot(), Nsound::FilterCombLowPassFeedback::plot(), Nsound::FilterBandRejectIIR::plot(), Nsound::FilterBandRejectFIR::plot(), Nsound::FilterBandPassIIR::plot(), Nsound::FilterBandPassFIR::plot(), Nsound::FilterAllPass::plot(), Nsound::FilterLowPassIIR::setCutoff(), and Nsound::FilterLeastSquaresFIR::setWindow().

float64 Nsound::Filter::two_pi_over_sample_rate_ [protected]

Definition at line 132 of file Filter.h.

Referenced by Nsound::FilterTone::makeKernel(), Nsound::FilterParametricEqualizer::makeKernel(), and Nsound::FilterLowPassFIR::makeKernel().

uint32 Nsound::Filter::kernel_size_ [protected]

Definition at line 133 of file Filter.h.

Referenced by Nsound::FilterLowPassFIR::filter(), Nsound::FilterLeastSquaresFIR::filter(), Nsound::FilterBandPassFIR::FilterBandPassFIR(), Nsound::FilterBandPassIIR::FilterBandPassIIR(), Nsound::FilterBandRejectIIR::FilterBandRejectIIR(), Nsound::FilterHighPassIIR::FilterHighPassIIR(), Nsound::FilterLeastSquaresFIR::FilterLeastSquaresFIR(), Nsound::FilterLowPassFIR::FilterLowPassFIR(), Nsound::FilterLowPassIIR::FilterLowPassIIR(), Nsound::FilterLeastSquaresFIR::getKernel(), getKernelSize(), Nsound::FilterLowPassFIR::makeKernel(), Nsound::FilterLeastSquaresFIR::makeKernel(), Nsound::FilterHighPassFIR::makeKernel(), Nsound::FilterBandRejectFIR::makeKernel(), Nsound::FilterLeastSquaresFIR::operator=(), Nsound::FilterLowPassFIR::plot(), Nsound::FilterLeastSquaresFIR::plot(), Nsound::FilterHighPassFIR::plot(), Nsound::FilterBandRejectFIR::plot(), Nsound::FilterLowPassFIR::reset(), Nsound::FilterLeastSquaresFIR::reset(), Nsound::FilterHighPassFIR::reset(), Nsound::FilterLeastSquaresFIR::setKernel(), Nsound::FilterLeastSquaresFIR::setWindow(), and Nsound::FilterHighPassFIR::spectraReversal_().

The documentation for this class was generated from the following files:
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