IIRFilter< Type, Order > Class Template Reference

#include <iirfilter.h>

Public Member Functions
	IIRFilter (const Type *a, const Type *b)
	~IIRFilter ()
void	setCoeffs (const Type *a, const Type *b)
Type	run (const Type &sample)

Private Attributes
Type *	m_a
Type *	m_b
Type *	m_x
Type *	m_y

Detailed Description

template<typename Type, uint32_t Order>
class IIRFilter< Type, Order >

IIR filter See: https://cdn.mikroe.com/ebooks/img/8/2016/02/digital-filter-design-chapter-03-image-2-9.gif

Definition at line 31 of file iirfilter.h.

Constructor & Destructor Documentation

IIRFilter()

template<typename Type, uint32_t Order>

IIRFilter< Type, Order >::IIRFilter	(	const Type *	a,
		const Type *	b
	)

Definition at line 62 of file iirfilter.h.

{
    assert(Order > 1);

    m_a = new Type[Order+1];
    m_b = new Type[Order+1];
    m_x = new Type[Order];
    m_y = new Type[Order];

    setCoeffs(a, b);
}

~IIRFilter()

template<typename Type , uint32_t Order>

IIRFilter< Type, Order >::~IIRFilter

(

)

Definition at line 75 of file iirfilter.h.

{
    delete[] m_y;
    delete[] m_x;
    delete[] m_b;
    delete[] m_a;
}

Member Function Documentation

run()

template<typename Type, uint32_t Order>

Type IIRFilter< Type, Order >::run

(

const Type &

sample

)

Definition at line 98 of file iirfilter.h.

Referenced by AudioFilter::run(), MBEAudioInterpolatorFilter::run(), AudioFilter::runHP(), MBEAudioInterpolatorFilter::runHP(), AudioFilter::runLP(), and MBEAudioInterpolatorFilter::runLP().

{
    Type y = m_b[0] * sample;

    for (uint32_t i = Order; i > 0; i--)
    {
        y += m_b[i] * m_x[i-1] + m_a[i] * m_y[i-1];

        if (i > 1) // shift
        {
            m_x[i-1] = m_x[i-2];
            m_y[i-1] = m_y[i-2];
        }
    }

    // last shift
    m_x[0] = sample;
    m_y[0] = y;

    return y;
}

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setCoeffs()

template<typename Type, uint32_t Order>

void IIRFilter< Type, Order >::setCoeffs	(	const Type *	a,
		const Type *	b
	)

Definition at line 84 of file iirfilter.h.

Referenced by IIRFilter< float, 2 >::IIRFilter(), IIRFilter< Type, 2 >::IIRFilter(), and AudioFilter::setDecimFilters().

{
    memcpy(m_a, b, (Order+1)*sizeof(Type));
    memcpy(m_b, a, (Order+1)*sizeof(Type));

    for (uint32_t i = 0; i < Order; i++)
    {
        m_x[i] = 0;
        m_y[i] = 0;
    }
}

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Member Data Documentation

m_a

template<typename Type, uint32_t Order>

Type* IIRFilter< Type, Order >::m_a

private

Definition at line 40 of file iirfilter.h.

Referenced by IIRFilter< float, 2 >::IIRFilter(), IIRFilter< float, 2 >::run(), IIRFilter< Type, 2 >::run(), IIRFilter< float, 2 >::setCoeffs(), IIRFilter< Type, 2 >::setCoeffs(), and IIRFilter< float, 2 >::~IIRFilter().

m_b

template<typename Type, uint32_t Order>

Type* IIRFilter< Type, Order >::m_b

private

Definition at line 41 of file iirfilter.h.

Referenced by IIRFilter< float, 2 >::IIRFilter(), IIRFilter< float, 2 >::run(), IIRFilter< Type, 2 >::run(), IIRFilter< float, 2 >::setCoeffs(), IIRFilter< Type, 2 >::setCoeffs(), and IIRFilter< float, 2 >::~IIRFilter().

m_x

template<typename Type, uint32_t Order>

Type* IIRFilter< Type, Order >::m_x

private

Definition at line 42 of file iirfilter.h.

Referenced by IIRFilter< float, 2 >::IIRFilter(), IIRFilter< float, 2 >::run(), IIRFilter< Type, 2 >::run(), IIRFilter< float, 2 >::setCoeffs(), IIRFilter< Type, 2 >::setCoeffs(), and IIRFilter< float, 2 >::~IIRFilter().

m_y

template<typename Type, uint32_t Order>

Type* IIRFilter< Type, Order >::m_y

private

Definition at line 43 of file iirfilter.h.

Referenced by IIRFilter< float, 2 >::IIRFilter(), IIRFilter< float, 2 >::run(), IIRFilter< Type, 2 >::run(), IIRFilter< float, 2 >::setCoeffs(), IIRFilter< Type, 2 >::setCoeffs(), and IIRFilter< float, 2 >::~IIRFilter().

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

• sdrbase/dsp/iirfilter.h