MultiResonantFilter< su > Class Template Reference

A generic filter for audio signals that can produce lowpass, highpass, bandpass and notch outputs at runtime. More...

#include <ResonantFilter.h>

Inheritance diagram for MultiResonantFilter< su >:

Detailed Description

template<typename su = uint8_t>
class MultiResonantFilter< su >

A generic filter for audio signals that can produce lowpass, highpass, bandpass and notch outputs at runtime.

Behaves like ResonantFilter for setting the resonance and cutoff frequency. Like ResonantFilter, it can be used on different sample sizes: MultiResonantFilter<uint8_t> and MultiResonantFilter<uint16_t> have been tested. For the former, both cutoff and resonance are uint8_t, hence between 0-255. For the later, both cutoff and resonance are uint16_t, hence between 0-65535.

Definition at line 184 of file ResonantFilter.h.

Public Member Functions
void	next (AudioOutputStorage_t in)
	Compute the filters, given an input signal. More...
AudioOutputStorage_t	low ()
	Return the input filtered with a lowpass filter. More...
AudioOutputStorage_t	high ()
	Return the input filtered with a highpass filter. More...
AudioOutputStorage_t	band ()
	Return the input filtered with a bandpass filter. More...
AudioOutputStorage_t	notch ()
	Return the input filtered with a notch filter. More...
void	setCutoffFreq (uint8_t cutoff)
	deprecated. More...
void	setResonance (uint8_t resonance)
	deprecated. More...
void	setCutoffFreqAndResonance (uint8_t cutoff, uint8_t resonance)
	Set the cut off frequency and resonance. More...

Protected Member Functions
void	advanceBuffers (AudioOutputStorage_t in)
AudioOutputStorage_t	current (AudioOutputStorage_t in, Int2Type< LOWPASS >)
AudioOutputStorage_t	current (AudioOutputStorage_t in, Int2Type< HIGHPASS >)
AudioOutputStorage_t	current (AudioOutputStorage_t in, Int2Type< BANDPASS >)
AudioOutputStorage_t	current (AudioOutputStorage_t in, Int2Type< NOTCH >)
IntegerType< sizeof(uint8_t)+sizeof(uint8_t)>::unsigned_type	ucfxmul (uint8_t a, typename IntegerType< sizeof(uint8_t)+sizeof(uint8_t)>::unsigned_type b)
IntegerType< sizeof(AudioOutputStorage_t)+sizeof(uint8_t) -1 >::signed_type	ifxmul (typename IntegerType< sizeof(AudioOutputStorage_t)+sizeof(uint8_t) -1 >::signed_type a, uint8_t b)
IntegerType< sizeof(AudioOutputStorage_t)+sizeof(AudioOutputStorage_t)>::signed_type	fxmul (typename IntegerType< sizeof(AudioOutputStorage_t)+sizeof(AudioOutputStorage_t)>::signed_type a, typename IntegerType< sizeof(AudioOutputStorage_t)+sizeof(uint8_t) -1 >::signed_type b)

Protected Attributes
uint8_t	q
uint8_t	f
IntegerType< sizeof(uint8_t)+sizeof(uint8_t)>::unsigned_type	fb
AudioOutputStorage_t	buf0
AudioOutputStorage_t	buf1
const uint8_t	FX_SHIFT
const uint8_t	FX_SHIFT_M_1
const uint8_t	SHIFTED_1

Member Function Documentation

band()

template<typename su = uint8_t>

AudioOutputStorage_t MultiResonantFilter< su >::band ( )

inline

Return the input filtered with a bandpass filter.

Returns

the filtered signal output.

Definition at line 206 of file ResonantFilter.h.

high()

template<typename su = uint8_t>

AudioOutputStorage_t MultiResonantFilter< su >::high ( )

inline

Return the input filtered with a highpass filter.

Returns

the filtered signal output.

Definition at line 202 of file ResonantFilter.h.

low()

template<typename su = uint8_t>

AudioOutputStorage_t MultiResonantFilter< su >::low ( )

inline

Return the input filtered with a lowpass filter.

Returns

the filtered signal output.

Definition at line 198 of file ResonantFilter.h.

next()

template<typename su = uint8_t>

void MultiResonantFilter< su >::next ( AudioOutputStorage_t  in )

inline

Compute the filters, given an input signal.

Parameters

in	the signal input. Should not be more than 8bits on 8bits platforms (Arduino) if using the 8bits version and not 16bits version.

Definition at line 190 of file ResonantFilter.h.

notch()

template<typename su = uint8_t>

AudioOutputStorage_t MultiResonantFilter< su >::notch ( )

inline

Return the input filtered with a notch filter.

Returns

the filtered signal output.

Definition at line 210 of file ResonantFilter.h.

setCutoffFreq()

void ResonantFilter< FILTER_TYPE, uint8_t >::setCutoffFreq ( uint8_t  cutoff )

inlineinherited

deprecated.

Use setCutoffFreqAndResonance(su cutoff, su resonance).

Set the cut off frequency,

Parameters

cutoff

use the range 0-255 to represent 0-8191 Hz (MOZZI_AUDIO_RATE/2) for ResonantFilter, cutoff use the range 0-65535 to represent 0-MOZZI_AUDIO_RATE/2. Be careful of distortion at the lower end, especially with high resonance.

Definition at line 91 of file ResonantFilter.h.

setCutoffFreqAndResonance()

void ResonantFilter< FILTER_TYPE, uint8_t >::setCutoffFreqAndResonance ( uint8_t  cutoff, uint8_t  resonance  )

inlineinherited

Set the cut off frequency and resonance.

Replaces setCutoffFreq() and setResonance(). (Because the internal calculations need to be done whenever either parameter changes.)

Parameters

cutoff	range 0-255 represents 0-8191 Hz (MOZZI_AUDIO_RATE/2) for ResonantFilter, range 0-65535 for ResonantFilter16 Be careful of distortion at the lower end, especially with high resonance.
resonance	range 0-255 for ResonantFilter, 0-65535 for ResonantFilter<FILTER_TYPE, uint16_t>, 255/65535 is most resonant.

Definition at line 114 of file ResonantFilter.h.

setResonance()

void ResonantFilter< FILTER_TYPE, uint8_t >::setResonance ( uint8_t  resonance )

inlineinherited

deprecated.

Use setCutoffFreqAndResonance(su cutoff, su resonance).

Set the resonance. If you hear unwanted distortion, back off the resonance. After setting resonance, you need to call setCuttoffFreq() to hear the change!

Parameters

resonance

in the range 0-255 for ResonantFilter, 0-65535 for ResonantFilter<FILTER_TYPE, uint16_t>, with 255/65535 being most resonant

Note

Remember to call setCuttoffFreq() after resonance is changed!

Definition at line 105 of file ResonantFilter.h.