Nsound::FilterBandPassIIR Class Reference

#include <Nsound/FilterBandPassIIR.h>

Inheritance diagram for Nsound::FilterBandPassIIR:

Public Member Functions
	FilterBandPassIIR (const float64 &sample_rate, uint32 kernel_size, const float64 &frequency_Hz_low, const float64 &frequency_Hz_high, const float64 &percent_ripple=0.0)
virtual	~FilterBandPassIIR ()
float64	getFrequencyLow () const
float64	getFrequencyHigh () const
AudioStream	filter (const AudioStream &x)
AudioStream	filter (const AudioStream &x, const float64 &f)
AudioStream	filter (const AudioStream &x, const Buffer &frequencies)
AudioStream	filter (const AudioStream &x, const float64 &f_low, const float64 &f_high)
AudioStream	filter (const AudioStream &x, const Buffer &low_frequencies, const Buffer &high_frequencies)
Buffer	filter (const Buffer &x)
Buffer	filter (const Buffer &x, const float64 &f)
Buffer	filter (const Buffer &x, const Buffer &frequencies)
Buffer	filter (const Buffer &x, const float64 &f_low, const float64 &f_high)
Buffer	filter (const Buffer &x, const Buffer &frequencies_Hz_low, const Buffer &frequencies_Hz_high)
virtual float64	filter (const float64 &x)
virtual float64	filter (const float64 &x, const float64 &frequency_Hz)
virtual float64	filter (const float64 &x, const float64 &frequency_Hz_low, const float64 &frequency_Hz_high)
void	plot (boolean show_fc=true, boolean show_phase=false)
void	reset ()
void	setRealtime (bool flag)
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)

Protected Attributes
FilterLowPassIIR *	low_
FilterHighPassIIR *	high_
float64	gain_
float64	sample_rate_
float64	two_pi_over_sample_rate_
float64	sample_time_
uint32	kernel_size_
bool	is_realtime_

Private Member Functions
	FilterBandPassIIR (const FilterBandPassIIR &copy)
FilterBandPassIIR &	operator= (const FilterBandPassIIR &rhs)

Detailed Description

Definition at line 49 of file FilterBandPassIIR.h.

Constructor & Destructor Documentation

FilterBandPassIIR::FilterBandPassIIR	(	const float64 &	sample_rate,
		uint32	kernel_size,
		const float64 &	frequency_Hz_low,
		const float64 &	frequency_Hz_high,
		const float64 &	percent_ripple = 0.0
	)

Definition at line 50 of file FilterBandPassIIR.cc.

References gain_, Nsound::Filter::getFrequencyResponse(), Nsound::Filter::getKernelSize(), Nsound::Buffer::getMax(), Nsound::Filter::kernel_size_, low_, and reset().

    :
    Filter(sample_rate),
    low_(new  FilterLowPassIIR(
        sample_rate,
        n_poles,
        frequency_Hz_high,
        percent_ripple)),
    high_(new FilterHighPassIIR(
        sample_rate,
        n_poles,
        frequency_Hz_low,
        percent_ripple)),
    gain_(1.0)
{
    reset();

    kernel_size_ = low_->getKernelSize() * 2;

    Buffer response = Filter::getFrequencyResponse();

    gain_ = 1.0 / response.getMax();
}

FilterBandPassIIR::~FilterBandPassIIR ( )

virtual

Definition at line 81 of file FilterBandPassIIR.cc.

References high_, and low_.

{
    delete low_;
    delete high_;
}

Nsound::FilterBandPassIIR::FilterBandPassIIR ( const FilterBandPassIIR &  copy )

private

Member Function Documentation

float64 FilterBandPassIIR::getFrequencyLow

(

)

const

Definition at line 89 of file FilterBandPassIIR.cc.

References Nsound::FilterHighPassIIR::getFrequency(), and high_.

{
    return high_->getFrequency();
}

float64 FilterBandPassIIR::getFrequencyHigh

(

)

const

Definition at line 96 of file FilterBandPassIIR.cc.

References Nsound::FilterLowPassIIR::getFrequency(), and low_.

{
    return low_->getFrequency();
}

AudioStream FilterBandPassIIR::filter

(

const AudioStream &

x

)

Definition at line 103 of file FilterBandPassIIR.cc.

References Nsound::Filter::filter().

Referenced by main(), my_main(), and Nsound::GuitarBass::play().

{
    return Filter::filter(x);
}

AudioStream FilterBandPassIIR::filter	(	const AudioStream &	x,
		const float64 &	f
	)

Definition at line 110 of file FilterBandPassIIR.cc.

References Nsound::Filter::filter().

{
    return Filter::filter(x);
}

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

Definition at line 117 of file FilterBandPassIIR.cc.

References Nsound::Filter::filter().

{
    return Filter::filter(x);
}

AudioStream FilterBandPassIIR::filter	(	const AudioStream &	x,
		const float64 &	f_low,
		const float64 &	f_high
	)

Definition at line 124 of file FilterBandPassIIR.cc.

References Nsound::FilterHighPassIIR::filter(), Nsound::FilterLowPassIIR::filter(), high_, and low_.

{
    return low_->filter(high_->filter(x, f_low), f_high);
}

AudioStream FilterBandPassIIR::filter	(	const AudioStream &	x,
		const Buffer &	low_frequencies,
		const Buffer &	high_frequencies
	)

Definition at line 131 of file FilterBandPassIIR.cc.

References Nsound::FilterHighPassIIR::filter(), Nsound::FilterLowPassIIR::filter(), high_, and low_.

{
    return low_->filter(high_->filter(x, f_low), f_high);
}

Buffer FilterBandPassIIR::filter

(

const Buffer &

x

)

Definition at line 141 of file FilterBandPassIIR.cc.

References Nsound::Filter::filter().

{
    return Filter::filter(x);
}

Buffer FilterBandPassIIR::filter	(	const Buffer &	x,
		const float64 &	f
	)

Definition at line 148 of file FilterBandPassIIR.cc.

References Nsound::Filter::filter().

{
    return Filter::filter(x);
}

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

Definition at line 155 of file FilterBandPassIIR.cc.

References Nsound::Filter::filter().

{
    return Filter::filter(x);
}

Buffer FilterBandPassIIR::filter	(	const Buffer &	x,
		const float64 &	f_low,
		const float64 &	f_high
	)

Definition at line 162 of file FilterBandPassIIR.cc.

References Nsound::FilterHighPassIIR::filter(), Nsound::FilterLowPassIIR::filter(), high_, and low_.

{
    return low_->filter(high_->filter(x,f_low), f_high);
}

Buffer FilterBandPassIIR::filter	(	const Buffer &	x,
		const Buffer &	frequencies_Hz_low,
		const Buffer &	frequencies_Hz_high
	)

Definition at line 169 of file FilterBandPassIIR.cc.

References Nsound::FilterHighPassIIR::filter(), Nsound::FilterLowPassIIR::filter(), high_, and low_.

{
    return low_->filter(high_->filter(x, f_low), f_high);
}

float64 FilterBandPassIIR::filter ( const float64 &  x )

virtual

Implements Nsound::Filter.

Definition at line 179 of file FilterBandPassIIR.cc.

References Nsound::FilterHighPassIIR::filter(), Nsound::FilterLowPassIIR::filter(), gain_, high_, and low_.

{
    return gain_ * low_->filter(high_->filter(x));
};

float64 FilterBandPassIIR::filter ( const float64 &  x, const float64 &  frequency_Hz  )

virtual

Implements Nsound::Filter.

Definition at line 186 of file FilterBandPassIIR.cc.

References Nsound::FilterHighPassIIR::filter(), Nsound::FilterLowPassIIR::filter(), gain_, high_, and low_.

{
    return gain_ * low_->filter(high_->filter(x));
}

float64 FilterBandPassIIR::filter ( const float64 &  x, const float64 &  frequency_Hz_low, const float64 &  frequency_Hz_high  )

virtual

Definition at line 193 of file FilterBandPassIIR.cc.

References Nsound::FilterHighPassIIR::filter(), Nsound::FilterLowPassIIR::filter(), gain_, high_, and low_.

{
    return gain_ * low_->filter(
        high_->filter(x,frequencies_Hz_low), frequencies_Hz_high);
}

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

Definition at line 204 of file FilterBandPassIIR.cc.

References Nsound::FilterHighPassIIR::getFrequency(), Nsound::FilterLowPassIIR::getFrequency(), Nsound::Filter::getKernelSize(), high_, low_, Nsound::Filter::plot(), and Nsound::Filter::sample_rate_.

Referenced by main().

{
    char title[256];
    sprintf(title,
        "Band Pass IIR Frequency Response\n"
        "order = %d, fl = %0.1f Hz, fh = %0.1f Hz, sr = %0.1f Hz",
        low_->getKernelSize() * 2,
        high_->getFrequency(),
        low_->getFrequency(),
        sample_rate_);

    Plotter pylab;

    uint32  n_rows = 1;

    if(show_phase)
    {
        n_rows = 2;
    }

    Filter::plot(show_phase);

    if(show_fc)
    {
        pylab.subplot(n_rows, 1, 1);

        pylab.axvline(low_->getFrequency(),"color='red'");
        pylab.axvline(high_->getFrequency(),"color='red'");

        pylab.title(title);
    }
}

void FilterBandPassIIR::reset ( )

virtual

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

Implements Nsound::Filter.

Definition at line 239 of file FilterBandPassIIR.cc.

References high_, low_, Nsound::FilterHighPassIIR::reset(), and Nsound::FilterLowPassIIR::reset().

Referenced by FilterBandPassIIR().

{
    low_->reset();
    high_->reset();
}

FilterBandPassIIR& Nsound::FilterBandPassIIR::operator= ( const FilterBandPassIIR &  rhs )

private

void Nsound::Filter::setRealtime ( bool  flag )

inlineinherited

Definition at line 57 of file Filter.h.

References Nsound::Filter::is_realtime_.

{is_realtime_ = flag;}

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

inherited

Definition at line 185 of file Filter.cc.

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

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

{
    uint32 fft_chunk_size = FFTransform::roundUp2(
        static_cast<int32>(n_fft));

    uint32 n_samples = fft_chunk_size / 2 + 1;

    float64 f_step = (1.0 / (static_cast<float64>(fft_chunk_size) / 2.0))
                   * (sample_rate_ / 2.0);

    Buffer f_axis;

    float64 f = 0.0;

    for(uint32 i = 0; i < n_samples; ++i)
    {
        f_axis << f;
        f += f_step;
    }

    return f_axis;
};

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

inherited

Definition at line 210 of file Filter.cc.

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

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

{
    FFTransform fft(sample_rate_);

//~    fft.setWindow(HANNING);

    FFTChunkVector vec;

    vec = fft.fft(getImpulseResponse(), n_fft);

    return vec[0].getMagnitude();
}

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

inherited

Definition at line 225 of file Filter.cc.

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

Referenced by Nsound::Filter::getFrequencyResponse(), Nsound::FilterHighPassFIR::getImpulseResponse(), Nsound::FilterLowPassFIR::getImpulseResponse(), Nsound::FilterLeastSquaresFIR::getImpulseResponse(), Nsound::FilterIIR::getImpulseResponse(), and Nsound::Filter::getPhaseResponse().

{
    if(!is_realtime_) reset();

    Buffer response(n_samples);

    response << filter(1.0);

    for(uint32 i = 1; i < n_samples; ++i)
    {
        response << filter(0.0);
    }

    if(!is_realtime_) reset();

    return response;
}

virtual uint32 Nsound::Filter::getKernelSize ( ) const

inlinevirtualinherited

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

Definition at line 96 of file Filter.h.

References Nsound::Filter::kernel_size_.

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

{return kernel_size_;};

Buffer Filter::getPhaseResponse ( )

inherited

Definition at line 245 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().

{
    uint32 n_samples = static_cast<uint32>(sample_rate_ * 2);

    FFTransform fft(n_samples);

    FFTChunkVector vec;

    vec = fft.fft(getImpulseResponse(), n_samples);

    Buffer phase = vec[0].getPhase();

    return phase.subbuffer(0, phase.getLength() / 2 + 1);
}

float64 Nsound::Filter::getSampleRate ( ) const

inlineinherited

Definition at line 102 of file Filter.h.

References Nsound::Filter::sample_rate_.

{ return sample_rate_; };

void Filter::plot ( boolean  show_phase = false )

inherited

Definition at line 262 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(), Nsound::FilterLowPassMoogVcf::plot(), Nsound::FilterPhaser::plot(), Nsound::FilterTone::plot(), Nsound::FilterHighPassIIR::plot(), Nsound::FilterCombLowPassFeedback::plot(), Nsound::FilterLowPassIIR::plot(), Nsound::FilterLowPassFIR::plot(), Nsound::FilterHighPassFIR::plot(), Nsound::FilterAllPass::plot(), Nsound::FilterBandPassVocoder::plot(), Nsound::FilterBandPassFIR::plot(), Nsound::FilterLeastSquaresFIR::plot(), Nsound::FilterFlanger::plot(), Nsound::FilterBandRejectFIR::plot(), Nsound::FilterBandRejectIIR::plot(), plot(), and Nsound::FilterParametricEqualizer::plot().

{
    Buffer x = getFrequencyAxis();
    Buffer fr = getFrequencyResponse().getdB();

    Plotter pylab;

    pylab.figure();

    uint32 n_rows = 1;
    uint32 n_cols = 1;

    if(show_phase)
    {
        n_rows = 2;
    }

    pylab.subplot(n_rows, n_cols, 1);

    // Frequency response
    pylab.plot(x,fr, "blue");

    pylab.xlabel("Frequency (Hz)");
    pylab.ylabel("Frequency Response (dB)");

    // Phase response
    if(show_phase)
    {
        pylab.subplot(n_rows, n_cols, 2);

        Buffer pr = getPhaseResponse().getdB();

        pylab.plot(x,pr);

        pylab.xlabel("Frequency (Hz)");
        pylab.ylabel("Phase Response (dB)");
    }

    float64 ymax = fr.getMax();
    float64 height = ymax - -60.0;

    pylab.ylim(-60.0, ymax + 0.05 * height);
}

Member Data Documentation

FilterLowPassIIR* Nsound::FilterBandPassIIR::low_

protected

Definition at line 135 of file FilterBandPassIIR.h.

Referenced by filter(), FilterBandPassIIR(), getFrequencyHigh(), plot(), reset(), and ~FilterBandPassIIR().

FilterHighPassIIR* Nsound::FilterBandPassIIR::high_

protected

Definition at line 136 of file FilterBandPassIIR.h.

Referenced by filter(), getFrequencyLow(), plot(), reset(), and ~FilterBandPassIIR().

float64 Nsound::FilterBandPassIIR::gain_

protected

Definition at line 137 of file FilterBandPassIIR.h.

Referenced by filter(), and FilterBandPassIIR().

float64 Nsound::Filter::sample_rate_

protectedinherited

Definition at line 113 of file Filter.h.

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

float64 Nsound::Filter::two_pi_over_sample_rate_

protectedinherited

Definition at line 114 of file Filter.h.

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

float64 Nsound::Filter::sample_time_

protectedinherited

Definition at line 115 of file Filter.h.

Referenced by Nsound::FilterLowPassMoogVcf::_make_filter().

uint32 Nsound::Filter::kernel_size_

protectedinherited

Definition at line 116 of file Filter.h.

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

bool Nsound::Filter::is_realtime_

protectedinherited

Definition at line 118 of file Filter.h.

Referenced by Nsound::Filter::filter(), Nsound::FilterBandRejectIIR::filter(), Nsound::FilterBandRejectFIR::filter(), Nsound::Filter::getImpulseResponse(), and Nsound::Filter::setRealtime().

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

• Nsound/FilterBandPassIIR.h
• Nsound/FilterBandPassIIR.cc