Nsound::FilterHighPassFIR Class Reference

#include <Nsound/FilterHighPassFIR.h>

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

List of all members.

Public Member Functions

 FilterHighPassFIR (const float64 &sample_rate, uint32 kernel_size, const float64 &cutoff_frequency_Hz)
virtual ~FilterHighPassFIR ()
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)
virtual float64 filter (const float64 &x, const float64 &frequency_Hz)
float64 getFrequency () const
Buffer getImpulseResponse ()
void makeKernel (const float64 &frequency)
void plot (boolean show_fc=true, boolean show_phase=false)
virtual void reset ()
Buffer getImpulseResponse (const uint32 n_samples=8192)
void plot (boolean show_phase=false)
void setCutoff (const float64 &fc)
Buffer getFrequencyAxis (const uint32 n_fft=8192)
Buffer getFrequencyResponse (const uint32 n_fft=8192)
virtual uint32 getKernelSize () const
Buffer getPhaseResponse ()
float64 getSampleRate () const

Protected Types

typedef std::set< KernelKernelCache

Protected Member Functions

void spectraReversal_ ()

Protected Attributes

FilterLowPassFIR::KernelCache hp_cache_
float64b_
float64window_
float64x_history_
float64x_ptr_
float64x_end_ptr_
float64 frequency_1_Hz_
KernelCache lp_cache_
float64 sample_rate_
float64 two_pi_over_sample_rate_
uint32 kernel_size_

Detailed Description

Definition at line 42 of file FilterHighPassFIR.h.


Member Typedef Documentation

typedef std::set<Kernel> Nsound::FilterLowPassFIR::KernelCache [protected, inherited]

Reimplemented in Nsound::FilterBandRejectFIR.

Definition at line 143 of file FilterLowPassFIR.h.


Constructor & Destructor Documentation

FilterHighPassFIR::FilterHighPassFIR ( const float64 sample_rate,
uint32  kernel_size,
const float64 cutoff_frequency_Hz 
)

Definition at line 46 of file FilterHighPassFIR.cc.

References Nsound::FilterLowPassFIR::frequency_1_Hz_, and reset().

00051     :
00052     FilterLowPassFIR(sample_rate, kernel_size, cutoff_frequency_Hz),
00053     hp_cache_()
00054 {
00055     frequency_1_Hz_ = cutoff_frequency_Hz;
00056     FilterHighPassFIR::reset();
}

FilterHighPassFIR::~FilterHighPassFIR (  )  [virtual]

Definition at line 60 of file FilterHighPassFIR.cc.

References hp_cache_.

00061 {
00062     KernelCache::iterator itor = hp_cache_.begin();
00063     KernelCache::iterator  end = hp_cache_.end();
00064 
00065     while(itor != end)
00066     {
00067         delete [] itor->b_;
00068         ++itor;
00069     }
00070 }


Member Function Documentation

AudioStream FilterHighPassFIR::filter ( const AudioStream x  ) 

Reimplemented from Nsound::FilterLowPassFIR.

Reimplemented in Nsound::FilterBandRejectFIR.

Definition at line 75 of file FilterHighPassFIR.cc.

Referenced by filter(), Nsound::FilterBandPassFIR::filter(), FilterHighPassFIR_UnitTest(), and main().

00076 {
00077     return Filter::filter(x);
00078 }

AudioStream FilterHighPassFIR::filter ( const AudioStream x,
const float64 frequency 
)

Reimplemented from Nsound::FilterLowPassFIR.

Definition at line 83 of file FilterHighPassFIR.cc.

References filter().

00084 {
00085     return Filter::filter(x, f);
00086 }

AudioStream FilterHighPassFIR::filter ( const AudioStream x,
const Buffer frequencies 
)

Reimplemented from Nsound::FilterLowPassFIR.

Definition at line 91 of file FilterHighPassFIR.cc.

References filter().

00092 {
00093     return Filter::filter(x, frequencies);
00094 }

Buffer FilterHighPassFIR::filter ( const Buffer x  ) 

Reimplemented from Nsound::FilterLowPassFIR.

Reimplemented in Nsound::FilterBandRejectFIR.

Definition at line 99 of file FilterHighPassFIR.cc.

References filter().

00100 {
00101     return Filter::filter(x);
00102 }

Buffer FilterHighPassFIR::filter ( const Buffer x,
const float64 frequency 
)

Reimplemented from Nsound::FilterLowPassFIR.

Definition at line 107 of file FilterHighPassFIR.cc.

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

00108 {
00109     // Instead of calling Filter::filter(x,f), we implement this function here
00110     // to avoid calling makeKernel(f) for each sample.
00111 
00112     FilterHighPassFIR::reset();
00113     FilterHighPassFIR::makeKernel(f);
00114 
00115     Buffer::const_iterator itor = x.begin();
00116     Buffer::const_iterator end = x.end();
00117 
00118     Buffer y;
00119     while(itor != end)
00120     {
00121         y << FilterLowPassFIR::filter(*itor);
00122         ++itor;
00123     }
00124 
00125     return y;
00126 }

Buffer FilterHighPassFIR::filter ( const Buffer x,
const Buffer frequencies 
)

Reimplemented from Nsound::FilterLowPassFIR.

Definition at line 131 of file FilterHighPassFIR.cc.

References filter().

00132 {
00133     return Filter::filter(x, frequencies);
00134 }

float64 FilterHighPassFIR::filter ( const float64 x  )  [virtual]

Reimplemented from Nsound::FilterLowPassFIR.

Reimplemented in Nsound::FilterBandRejectFIR.

Definition at line 139 of file FilterHighPassFIR.cc.

References filter().

00140 {
00141     return FilterLowPassFIR::filter(x);
00142 }

float64 FilterHighPassFIR::filter ( const float64 x,
const float64 frequency_Hz 
) [virtual]

Reimplemented from Nsound::FilterLowPassFIR.

Reimplemented in Nsound::FilterBandRejectFIR.

Definition at line 147 of file FilterHighPassFIR.cc.

References filter(), and makeKernel().

00148 {
00149     FilterHighPassFIR::makeKernel(frequency_Hz);
00150     return FilterLowPassFIR::filter(x);
00151 }

float64 Nsound::FilterHighPassFIR::getFrequency (  )  const [inline]
Buffer FilterHighPassFIR::getImpulseResponse (  ) 

Reimplemented from Nsound::FilterLowPassFIR.

Definition at line 156 of file FilterHighPassFIR.cc.

00157 {
00158     return Filter::getImpulseResponse();
00159 }

void FilterHighPassFIR::makeKernel ( const float64 frequency  ) 

Reimplemented from Nsound::FilterLowPassFIR.

Definition at line 164 of file FilterHighPassFIR.cc.

References Nsound::FilterLowPassFIR::Kernel::b_, Nsound::FilterLowPassFIR::b_, hp_cache_, Nsound::Filter::kernel_size_, Nsound::Filter::sample_rate_, and spectraReversal_().

Referenced by filter(), and reset().

00165 {
00166     // Here we create a key into the kernel cache.  I'm only storing kernels
00167     // with freqs chopped off to the 10th Hz.  So filtering with a kernel
00168     // designed at 440.1567 Hz will get stored as 440.1.  Any other frequency
00169     // that starts at 440.1 will not get a kernel calculated and just use the
00170     // one in the cache.
00171 
00172     FilterLowPassFIR::Kernel new_kernel(
00173         static_cast<uint32>(cutoff_frequency_Hz));
00174 
00175     // See if the kernel is in the cache.
00176 
00177     FilterLowPassFIR::
00178     KernelCache::
00179     const_iterator itor = hp_cache_.find(new_kernel);
00180 
00181     if(itor != hp_cache_.end())
00182     {
00183         // The kernel was found in the cache.
00184         b_ = itor->b_;
00185         return;
00186     }
00187 
00188     // The filter wasn't in the cache, need to make it.
00189     new_kernel.b_ = new float64[kernel_size_];
00190 
00191     if(cutoff_frequency_Hz < 0.10)
00192     {
00193         // Create All pass filter.
00194         new_kernel.b_[0] = 1.0;
00195 
00196         b_ = new_kernel.b_;
00197     }
00198     else
00199     {
00200         float64 fc = sample_rate_ / 2.0 - cutoff_frequency_Hz;
00201 
00202         FilterLowPassFIR::makeKernel(fc);
00203 
00204         // Now b_ is pointing to a low pass kernel, copy it into new_kernel.
00205         memcpy(new_kernel.b_, b_, sizeof(float64) * kernel_size_);
00206 
00207         // Point to new kernel.
00208         b_ = new_kernel.b_;
00209 
00210         // Perform the spectra inversion on the kernel to turn it into a high
00211         // pass filter.
00212         spectraReversal_();
00213     }
00214 
00215     // Add the new kernel to the cache.
00216     hp_cache_.insert(new_kernel);
00217 }

void FilterHighPassFIR::plot ( boolean  show_fc = true,
boolean  show_phase = false 
)

Reimplemented from Nsound::FilterLowPassFIR.

Reimplemented in Nsound::FilterBandRejectFIR.

Definition at line 222 of file FilterHighPassFIR.cc.

References Nsound::Plotter::axvline(), Nsound::FilterLowPassFIR::frequency_1_Hz_, Nsound::Filter::kernel_size_, Nsound::Filter::sample_rate_, Nsound::Plotter::subplot(), and Nsound::Plotter::title().

Referenced by main().

00225 {
00226     char title[128];
00227     sprintf(title,
00228         "High Pass FIR Frequency Response\n"
00229         "order = %d, fc = %0.1f Hz, sr = %0.1f Hz",
00230         kernel_size_ - 1, frequency_1_Hz_, sample_rate_);
00231 
00232     Filter::plot(show_phase);
00233 
00234     Plotter pylab;
00235 
00236     int32 topplot = 111;
00237 
00238     if(show_phase)
00239     {
00240         topplot = 211;
00241     }
00242 
00243     if(show_fc)
00244     {
00245         pylab.subplot(topplot);
00246 
00247         pylab.axvline(frequency_1_Hz_,"color='red'");
00248 
00249         pylab.title(title);
00250     }
00251 
00252 }

void FilterHighPassFIR::reset (  )  [virtual]

Resets interal history buffer and sets the cut off frequency to the one used at declaration.

Reimplemented from Nsound::FilterLowPassFIR.

Reimplemented in Nsound::FilterBandRejectFIR.

Definition at line 257 of file FilterHighPassFIR.cc.

References Nsound::FilterLowPassFIR::frequency_1_Hz_, Nsound::Filter::kernel_size_, makeKernel(), Nsound::FilterLowPassFIR::x_history_, and Nsound::FilterLowPassFIR::x_ptr_.

Referenced by filter(), FilterHighPassFIR(), and Nsound::FilterBandPassFIR::reset().

00258 {
00259     // Don't call FilterLowPassFIR::reset(), if we did, we would be creating
00260     // a kernel twice.
00261 
00262     memset(x_history_, 0, sizeof(float64) * (kernel_size_ + 1));
00263     x_ptr_ = x_history_;
00264 
00265     FilterHighPassFIR::makeKernel(frequency_1_Hz_);
00266 }

void FilterHighPassFIR::spectraReversal_ (  )  [protected]

Definition at line 271 of file FilterHighPassFIR.cc.

References Nsound::FilterLowPassFIR::b_, and Nsound::Filter::kernel_size_.

Referenced by makeKernel().

00272 {
00273     for(uint32 i = 0; i < kernel_size_; ++i)
00274     {
00275         if(i % 2)
00276         {
00277             b_[i] *= -1.00;
00278         }
00279     }
00280 }

Buffer Filter::getImpulseResponse ( const uint32  n_samples = 8192  )  [inherited]

Reimplemented in Nsound::FilterIIR.

Definition at line 218 of file Filter.cc.

References Nsound::Filter::filter(), and Nsound::Filter::reset().

Referenced by Nsound::Filter::getFrequencyResponse(), and Nsound::Filter::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 }

void Filter::plot ( boolean  show_phase = false  )  [inherited]

Definition at line 257 of file Filter.cc.

References Nsound::Plotter::figure(), Nsound::Buffer::getdB(), Nsound::Filter::getFrequencyAxis(), Nsound::Filter::getFrequencyResponse(), Nsound::Buffer::getMax(), Nsound::Filter::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 }

void FilterLowPassFIR::setCutoff ( const float64 fc  )  [inherited]

Sets the cut off frequency (Hz).

Definition at line 379 of file FilterLowPassFIR.cc.

References Nsound::FilterLowPassFIR::frequency_1_Hz_, and Nsound::FilterLowPassFIR::reset().

00380 {
00381     frequency_1_Hz_ = fc;
00382     reset();
00383 }

Buffer Filter::getFrequencyAxis ( const uint32  n_fft = 8192  )  [inherited]

Definition at line 176 of file Filter.cc.

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

Referenced by main(), Nsound::Filter::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  )  [inherited]

Definition at line 202 of file Filter.cc.

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

Referenced by Nsound::FilterBandPassIIR::FilterBandPassIIR(), FilterLeastSquaresFIR_UnitTest(), Nsound::FilterIIR::getRMS(), main(), Nsound::Filter::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 }

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

Definition at line 239 of file Filter.cc.

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

Referenced by Nsound::Filter::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, inherited]

Definition at line 117 of file Filter.h.

References Nsound::Filter::sample_rate_.

00117 { return sample_rate_; };


Member Data Documentation

Definition at line 116 of file FilterHighPassFIR.h.

Referenced by makeKernel(), and ~FilterHighPassFIR().

float64* Nsound::FilterLowPassFIR::b_ [protected, inherited]
float64* Nsound::FilterLowPassFIR::window_ [protected, inherited]
float64* Nsound::FilterLowPassFIR::x_ptr_ [protected, inherited]
float64 Nsound::Filter::sample_rate_ [protected, inherited]

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(), Nsound::Filter::getFrequencyAxis(), Nsound::Filter::getFrequencyResponse(), Nsound::Filter::getPhaseResponse(), Nsound::Filter::getSampleRate(), Nsound::FilterStageIIR::makeIIRKernelHelper(), Nsound::FilterStageIIR::makeKernel(), Nsound::FilterParametricEqualizer::makeKernel(), Nsound::FilterLeastSquaresFIR::makeKernel(), 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(), 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().

uint32 Nsound::Filter::kernel_size_ [protected, inherited]

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