ResonantFilter< FILTER_TYPE, su > Class Template Reference

A generic resonant filter for audio signals. More...

#include <ResonantFilter.h>

Detailed Description

template<int8_t FILTER_TYPE, typename su = uint8_t>
class ResonantFilter< FILTER_TYPE, su >

A generic resonant filter for audio signals.

Definition at line 75 of file ResonantFilter.h.

Public Member Functions
	ResonantFilter ()
	Constructor.
void	setCutoffFreq (su cutoff)
	deprecated. More...
void	setResonance (su resonance)
	deprecated. More...
void	setCutoffFreqAndResonance (su cutoff, su resonance)
	Set the cut off frequency and resonance. More...
AudioOutputStorage_t	next (AudioOutputStorage_t in)
	Calculate the next sample, given an input signal. 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(su)+sizeof(su)>::unsigned_type	ucfxmul (su a, typename IntegerType< sizeof(su)+sizeof(su)>::unsigned_type b)
IntegerType< sizeof(AudioOutputStorage_t)+sizeof(su) -1 >::signed_type	ifxmul (typename IntegerType< sizeof(AudioOutputStorage_t)+sizeof(su) -1 >::signed_type a, su 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(su) -1 >::signed_type b)

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

Member Function Documentation

next()

template<int8_t FILTER_TYPE, typename su = uint8_t>

AudioOutputStorage_t ResonantFilter< FILTER_TYPE, su >::next ( AudioOutputStorage_t  in )

inline

Calculate the next sample, 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.

Returns

the signal output.

Note

Timing: about 11us.

Definition at line 128 of file ResonantFilter.h.

setCutoffFreq()

template<int8_t FILTER_TYPE, typename su = uint8_t>

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

inline

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()

template<int8_t FILTER_TYPE, typename su = uint8_t>

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

inline

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()

template<int8_t FILTER_TYPE, typename su = uint8_t>

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

inline

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.