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Public Member Functions | Public Attributes | Protected Member Functions | Static Protected Member Functions | Protected Attributes | Static Protected Attributes | List of all members
SimpleChorus< effectsuite_t > Class Template Reference

Simple Chorus effect with a single delay voice and mono output Chorus is effective between 15 and 20 miliseconds delay of original audio. Requires the sample rate when initialising. More...

#include <AudioEffectsSuite.h>

Inheritance diagram for SimpleChorus< effectsuite_t >:
DelayEffectBase< effectsuite_t > ModulationBaseClass< effectsuite_t > SimpleLPF< effectsuite_t > FilterEffectBase< effectsuite_t > EffectSuiteBase< effectsuite_t > AudioEffect

Public Member Functions

 SimpleChorus (int extSampleRate=44100)
 
 SimpleChorus (SimpleChorus &copy)=default
 
 ~SimpleChorus ()=default
 
virtual bool active ()
 determines if the effect is active
 
virtual effectsuite_t applyFilter (effectsuite_t sampVal)
 
void clipWave (effectsuite_t amp)
 
SimpleChorusclone () override
 
effectsuite_t envelope (effectsuite_t sample)
 
int id ()
 Allows to identify an effect.
 
bool isNoise ()
 
void printInterpTable ()
 
virtual effect_t process (effect_t inputSample) override
 see applyFilter
 
virtual effectsuite_t processFloat (effectsuite_t inputSample) override
 
effectsuite_t readNoise ()
 
effectsuite_t readTable (effectsuite_t freq)
 
virtual void setActive (bool value)
 sets the effect active/inactive
 
void setBase (effectsuite_t baseAmount)
 
bool setChebyICoefficients (effectsuite_t cutFreqIn, bool shelfType, effectsuite_t rippleIn)
 
void setDC ()
 
void setId (int id)
 Allows to identify an effect.
 
bool setInterpTable ()
 
void setNoise ()
 
void setOffSine ()
 
void setRamp ()
 
void setSawtooth ()
 
void setSine ()
 
void setSquare ()
 
void setSwing (effectsuite_t swingAmount)
 
void setTriangle ()
 
void setupChorus (effectsuite_t extSampleRate)
 
void setupDelayEffectBase (const int bufferSizeSamples)
 
void setupModulationBaseClass (effectsuite_t extSampRate)
 setup the class with a given sample rate. Basically reperforming the constructor
 

Public Attributes

int sampleRate
 
effectsuite_t tableIndex = 0
 
effectsuite_t timeStep
 
effectsuite_t * waveTable = nullptr
 

Protected Member Functions

void allocateBufferMemory ()
 
bool allocateMemory ()
 
bool changeChebyICoefficients (effectsuite_t cutFreq, bool shelfType, effectsuite_t ripple, int poles)
 
void clearMemory ()
 
int16_t clip (int32_t in, int16_t clipLimit=32767, int16_t resultLimit=32767)
 generic clipping method
 
void copyParent (AudioEffect *copy)
 
void delaySample (effectsuite_t inputSample)
 
effectsuite_t getInterpolatedOut (effectsuite_t bufferIndex)
 
effectsuite_t getInterpOut (effectsuite_t bufferIndex)
 
effectsuite_t getModSignal ()
 
effectsuite_t getSplineOut (effectsuite_t bufferIndex, int freq)
 
void incBufferIndex ()
 
void incDelayBuffReadIndex (effectsuite_t indexInc)
 
void incDelayBuffWriteIndex ()
 
effectsuite_t rms (effectsuite_t sample)
 
bool setDelayBuffer (int bufferSizeSamples)
 
void setDelayBuffReadIndex (effectsuite_t index)
 
void setRandLfo ()
 
bool setSimpleLpf (int order)
 
void storeSample (effectsuite_t inputSample)
 

Static Protected Member Functions

static effectsuite_t ** setInterpolationTable ()
 

Protected Attributes

bool active_flag = true
 
effectsuite_t base
 
int bufferIndex = 0
 
effectsuite_t currentDelayReadIndex = 0
 
int currentDelayWriteIndex = 0
 
effectsuite_t * delayBuffer = 0
 
int delayTimeSamples = 44100
 
bool error
 
int filterOrder = 0
 
float * firBuffer = 0
 
float * firCoefficients = 0
 
float * firTemp = 0
 
int id_value = -1
 
float * iirBuffer = 0
 
float * iirCoefficients = 0
 
float * iirTemp = 0
 
effectsuite_t interpTable [order][res]
 
bool is_noise = false
 
int maxDelayBufferSize = 441000
 
effectsuite_t modMax = .5
 
effectsuite_t modMin = .5
 
effectsuite_t modNorm = 1 / (modMax - modMin)
 
const effectsuite_t readSpeed = ((this->readNoise() + 1) * .5) * .0005
 
effectsuite_t * rmsBuffer = new effectsuite_t[rmsWindowSize]
 
int rmsBufferIndex = 0
 
const int rmsWindowSize = 128
 
int samplingRate = 0
 
effectsuite_t swing
 

Static Protected Attributes

static effectsuite_t ** interpolationTable = nullptr
 Table of interpolation values as a 2D array indexed by interpolationTable[pointIndex][alphaIndex]. One instance per DelayEffectBase<effectsuite_t> instantiation (previously a single namespace-scope global shared – and type-mismatched – across every effectsuite_t choice).
 
static const int interpOrder = 4
 
static const int interpResolution = 1000
 
static const int order = 4
 
static const int res = 100
 

Detailed Description

template<typename effectsuite_t = effectsuite_t_default>
class audio_tools::SimpleChorus< effectsuite_t >

Simple Chorus effect with a single delay voice and mono output Chorus is effective between 15 and 20 miliseconds delay of original audio. Requires the sample rate when initialising.

Author
Matthew Hamilton

Constructor & Destructor Documentation

◆ SimpleChorus() [1/2]

template<typename effectsuite_t = effectsuite_t_default>
SimpleChorus ( int  extSampleRate = 44100)
inline

Constructor: initialises the effect parameters Since the class inherits DelayEffectBase it must set a delay buffer size when initialisi.

◆ SimpleChorus() [2/2]

template<typename effectsuite_t = effectsuite_t_default>
SimpleChorus ( SimpleChorus< effectsuite_t > &  copy)
default

◆ ~SimpleChorus()

template<typename effectsuite_t = effectsuite_t_default>
~SimpleChorus ( )
default

Member Function Documentation

◆ active()

virtual bool active ( )
inlinevirtualinherited

determines if the effect is active

◆ allocateBufferMemory()

template<typename effectsuite_t = effectsuite_t_default>
void allocateBufferMemory ( )
inlineprotectedinherited

will allocate memory to a buffer given the current filter order and set all values == 0.00

◆ allocateMemory()

template<typename effectsuite_t = effectsuite_t_default>
bool allocateMemory ( )
inlineprotectedinherited

allocate memory to internal wave table based on sample rate

Returns
returns true on success or false on failure

◆ applyFilter()

template<typename effectsuite_t = effectsuite_t_default>
virtual effectsuite_t applyFilter ( effectsuite_t  sampVal)
inlinevirtualinherited

with the current filter coefficients this method filters a sample then stores it the sample Buffer and increments the index

Parameters
sampValis the sample to be processed
Returns
filtered audio sample

◆ changeChebyICoefficients()

template<typename effectsuite_t = effectsuite_t_default>
bool changeChebyICoefficients ( effectsuite_t  cutFreq,
bool  shelfType,
effectsuite_t  ripple,
int  poles 
)
inlineprotectedinherited

set firCoefficients and iirCoefficients for required chebyshev type I filter sampleBuffer memory is also set @params cutFreq normalised cutoff frequency (0 < x < .5) @params shelfType bool filter shelf type, false = low pass, true = high pass @params ripple percentage ripple (<.2929) @params poles number of poles

Returns
boolean false on error and true on success

◆ clearMemory()

template<typename effectsuite_t = effectsuite_t_default>
void clearMemory ( )
inlineprotectedinherited

checks internal memory storage of filter coeffcients and deletes if required

◆ clip()

int16_t clip ( int32_t  in,
int16_t  clipLimit = 32767,
int16_t  resultLimit = 32767 
)
inlineprotectedinherited

generic clipping method

◆ clipWave()

template<typename effectsuite_t = effectsuite_t_default>
void clipWave ( effectsuite_t  amp)
inlineinherited

clip wave table values with a tanh function. Effect change with a variable amp to control intensity.

Parameters
ampamount to multiply signal before being fed through a tanh function

◆ clone()

template<typename effectsuite_t = effectsuite_t_default>
SimpleChorus * clone ( )
inlineoverridevirtual

Implements AudioEffect.

◆ copyParent()

void copyParent ( AudioEffect copy)
inlineprotectedinherited

◆ delaySample()

template<typename effectsuite_t = effectsuite_t_default>
void delaySample ( effectsuite_t  inputSample)
inlineprotectedinherited

store input sample into the delay buffer and increment currentDelayWriteIndex for tracking when to loop back to start of buffer

Parameters
inputSamplesample to be stored for delay (effectsuite_t)

◆ envelope()

template<typename effectsuite_t = effectsuite_t_default>
effectsuite_t envelope ( effectsuite_t  sample)
inlineinherited

detect the envelop of an incoming signal

Parameters
samplethe incoming signal sample value
Returns
returns envelope dection signal sample value

◆ getInterpolatedOut()

template<typename effectsuite_t = effectsuite_t_default>
effectsuite_t getInterpolatedOut ( effectsuite_t  bufferIndex)
inlineprotectedinherited

get the value of the requested buffer index by interpolating other points

Parameters
bufferIndexThe required buffer index
Returns
interpolated output

◆ getInterpOut()

template<typename effectsuite_t = effectsuite_t_default>
effectsuite_t getInterpOut ( effectsuite_t  bufferIndex)
inlineprotectedinherited

get the interpolated output of the waveTable from the given buffer index

Parameters
bufferIndexbuffer index as effectsuite_t
Returns
returns interpolated value from surrounding wavtable indices

◆ getModSignal()

template<typename effectsuite_t = effectsuite_t_default>
effectsuite_t getModSignal ( )
inlineprotected

modulation signal scaling equation: ((n - modMin)*modNorm*swing) + base modulates a random white noise signal by lowpass filtering then scaling to a range between 15 to 25 miliseconds of delay.

◆ getSplineOut()

template<typename effectsuite_t = effectsuite_t_default>
effectsuite_t getSplineOut ( effectsuite_t  bufferIndex,
int  freq 
)
inlineprotectedinherited

get a cubic spline interpolated out from the wave table

Derived from code by Alec Wright at repository: https://github.com/Alec-Wright/Chorus

Authors
Matthew Hamilton, Alec Wright
Parameters
bufferIndexthe required buffer index
freq(speed) that the table is being read through
Returns
returns interpolated value as effectsuite_t

◆ id()

int id ( )
inlineinherited

Allows to identify an effect.

◆ incBufferIndex()

template<typename effectsuite_t = effectsuite_t_default>
void incBufferIndex ( )
inlineprotectedinherited

increment the buffer index and wrap it to the filter order

◆ incDelayBuffReadIndex()

template<typename effectsuite_t = effectsuite_t_default>
void incDelayBuffReadIndex ( effectsuite_t  indexInc)
inlineprotectedinherited

Increments the currentDelayBufferReadIndex by indexInc

Parameters
indexIncThe amount to increment the delay buffer index

◆ incDelayBuffWriteIndex()

template<typename effectsuite_t = effectsuite_t_default>
void incDelayBuffWriteIndex ( )
inlineprotectedinherited

Increments the currentDelayWriteBufferIndex by 1

◆ isNoise()

template<typename effectsuite_t = effectsuite_t_default>
bool isNoise ( )
inlineinherited

◆ printInterpTable()

template<typename effectsuite_t = effectsuite_t_default>
void printInterpTable ( )
inlineinherited

◆ process()

template<typename effectsuite_t = effectsuite_t_default>
virtual effect_t process ( effect_t  inputSample)
inlineoverridevirtualinherited

see applyFilter

Reimplemented from EffectSuiteBase< effectsuite_t >.

Reimplemented in FilteredDelay< effectsuite_t >.

◆ processFloat()

template<typename effectsuite_t = effectsuite_t_default>
virtual effectsuite_t processFloat ( effectsuite_t  inputSample)
inlineoverridevirtual

apply chorus effect to audio sample

Parameters
inputSampleinput audio sample
Returns
processed audio sample

Reimplemented from FilterEffectBase< effectsuite_t >.

◆ readNoise()

template<typename effectsuite_t = effectsuite_t_default>
effectsuite_t readNoise ( )
inlineinherited

reads out white noise

Returns
random number between -1 and 1

◆ readTable()

template<typename effectsuite_t = effectsuite_t_default>
effectsuite_t readTable ( effectsuite_t  freq)
inlineinherited

Read through values in waveTable as a given frequency

Parameters
freqread speed in Hz: essentially the number of samples jumped between reads
Returns
value from table as effectsuite_t

◆ rms()

template<typename effectsuite_t = effectsuite_t_default>
effectsuite_t rms ( effectsuite_t  sample)
inlineprotectedinherited

root mean square of signal over a specific sample window

◆ setActive()

virtual void setActive ( bool  value)
inlinevirtualinherited

sets the effect active/inactive

◆ setBase()

template<typename effectsuite_t = effectsuite_t_default>
void setBase ( effectsuite_t  baseAmount)
inline

sets the 'base' of the chorus: the minimum delay in the signal.

Parameters
baseAmount<#baseAmount description#>

◆ setChebyICoefficients()

template<typename effectsuite_t = effectsuite_t_default>
bool setChebyICoefficients ( effectsuite_t  cutFreqIn,
bool  shelfType,
effectsuite_t  rippleIn 
)
inlineinherited

changes the current Chebyshev type 1 coefficients without altering the filter order. This allows for use in an audio process thread as it avoids dynamic allocation of memory. Filter sample and coefficient buffers are unaltered for initialising a chebyshev type 1 filter

See also
setChebyICoefficients @params cutFreq normalised cutoff frequency (0 < x < .5) @params shelfType bool Filters shelf type, false = low pass, true = high pass @params ripple percentage ripple (<.2929)
Returns
boolean false on error and true on success

◆ setDC()

template<typename effectsuite_t = effectsuite_t_default>
void setDC ( )
inlineinherited

sets wavetable to DC one

◆ setDelayBuffer()

template<typename effectsuite_t = effectsuite_t_default>
bool setDelayBuffer ( int  bufferSizeSamples)
inlineprotectedinherited

Allocates memory for delay buffer and initialises all elements to 0

Parameters
bufferSizeSamplesthe size of delay buffer to be used
Returns
false and error description if there's a problem, or sets the internal delay buffer and returns true

◆ setDelayBuffReadIndex()

template<typename effectsuite_t = effectsuite_t_default>
void setDelayBuffReadIndex ( effectsuite_t  index)
inlineprotectedinherited

sets the currentDelayBufferReadIndex by indexInc (Currently no wrapping)

Parameters
indexthe read index index required

◆ setId()

void setId ( int  id)
inlineinherited

Allows to identify an effect.

◆ setInterpolationTable()

template<typename effectsuite_t = effectsuite_t_default>
static effectsuite_t ** setInterpolationTable ( )
inlinestaticprotectedinherited

Sets the internal lagrange interpolation table. Ideally it should be shared amongst all

Returns
false and an error description if there's a problem, or sets the interpolation lookup table and returns true

◆ setInterpTable()

template<typename effectsuite_t = effectsuite_t_default>
bool setInterpTable ( )
inlineinherited

populates the internal interpolation table

Returns
return tru on success, else false

◆ setNoise()

template<typename effectsuite_t = effectsuite_t_default>
void setNoise ( )
inlineinherited

◆ setOffSine()

template<typename effectsuite_t = effectsuite_t_default>
void setOffSine ( )
inlineinherited

sets wavetable to one period of a sine wave oscillating between 0 and 1

◆ setRamp()

template<typename effectsuite_t = effectsuite_t_default>
void setRamp ( )
inlineinherited

set wave table to be a ramp from 0 to 1

◆ setRandLfo()

template<typename effectsuite_t = effectsuite_t_default>
void setRandLfo ( )
inlineprotected

◆ setSawtooth()

template<typename effectsuite_t = effectsuite_t_default>
void setSawtooth ( )
inlineinherited

sets wavetable to one period of a sawtooth wave

◆ setSimpleLpf()

template<typename effectsuite_t = effectsuite_t_default>
bool setSimpleLpf ( int  order)
inlineprotectedinherited

a simple normalised fir low pass filter @params order number of delay coefficients

◆ setSine()

template<typename effectsuite_t = effectsuite_t_default>
void setSine ( )
inlineinherited

sets wavetable to one period of a sine wave oscillating between -1 and 1

◆ setSquare()

template<typename effectsuite_t = effectsuite_t_default>
void setSquare ( )
inlineinherited

sets wavetable to one period of a square wave

◆ setSwing()

template<typename effectsuite_t = effectsuite_t_default>
void setSwing ( effectsuite_t  swingAmount)
inline

set the 'swing' of the chorus: The amount intensity of vibrato in the delay signal

Parameters
swingAmount<#swingAmount description#>

◆ setTriangle()

template<typename effectsuite_t = effectsuite_t_default>
void setTriangle ( )
inlineinherited

sets wavetable to one period of a triangle wave

◆ setupChorus()

template<typename effectsuite_t = effectsuite_t_default>
void setupChorus ( effectsuite_t  extSampleRate)
inline

set parameters and internal sample rate

Parameters
extSampleRateexternal sample rate

◆ setupDelayEffectBase()

template<typename effectsuite_t = effectsuite_t_default>
void setupDelayEffectBase ( const int  bufferSizeSamples)
inlineinherited

<Description#>

Parameters
bufferSizeSamples<#bufferSizeSamples description#>

◆ setupModulationBaseClass()

template<typename effectsuite_t = effectsuite_t_default>
void setupModulationBaseClass ( effectsuite_t  extSampRate)
inlineinherited

setup the class with a given sample rate. Basically reperforming the constructor

Parameters
extSampRateExternal sample rate

◆ storeSample()

template<typename effectsuite_t = effectsuite_t_default>
void storeSample ( effectsuite_t  inputSample)
inlineprotectedinherited

store input sample into the delay buffer

Parameters
inputSamplesample to be stored for delay (effectsuite_t)

Member Data Documentation

◆ active_flag

bool active_flag = true
protectedinherited

◆ base

template<typename effectsuite_t = effectsuite_t_default>
effectsuite_t base
protected

minimum delay in samples. Typically 10 milliseconds

◆ bufferIndex

template<typename effectsuite_t = effectsuite_t_default>
int bufferIndex = 0
protectedinherited

current buffer index

◆ currentDelayReadIndex

template<typename effectsuite_t = effectsuite_t_default>
effectsuite_t currentDelayReadIndex = 0
protectedinherited

◆ currentDelayWriteIndex

template<typename effectsuite_t = effectsuite_t_default>
int currentDelayWriteIndex = 0
protectedinherited

◆ delayBuffer

template<typename effectsuite_t = effectsuite_t_default>
effectsuite_t* delayBuffer = 0
protectedinherited

buffer to stored audio buffer for delay effects

◆ delayTimeSamples

template<typename effectsuite_t = effectsuite_t_default>
int delayTimeSamples = 44100
protectedinherited

the delay time of signal in samples

◆ error

template<typename effectsuite_t = effectsuite_t_default>
bool error
protectedinherited

internal class error boolean

◆ filterOrder

template<typename effectsuite_t = effectsuite_t_default>
int filterOrder = 0
protectedinherited

order of delay filter including the zero delay coefficients

◆ firBuffer

template<typename effectsuite_t = effectsuite_t_default>
float* firBuffer = 0
protectedinherited

buffer to hold forward delay sample data

◆ firCoefficients

template<typename effectsuite_t = effectsuite_t_default>
float* firCoefficients = 0
protectedinherited

Numerator coefficients in delay filter firCoefficients[0] z^0 coeffcieint firCoefficients[1] z^-1 coefficient

◆ firTemp

template<typename effectsuite_t = effectsuite_t_default>
float* firTemp = 0
protectedinherited

hold temporary values for fir coeffcient buffer

◆ id_value

int id_value = -1
protectedinherited

◆ iirBuffer

template<typename effectsuite_t = effectsuite_t_default>
float* iirBuffer = 0
protectedinherited

buffer to hold backward delay sample data

◆ iirCoefficients

template<typename effectsuite_t = effectsuite_t_default>
float* iirCoefficients = 0
protectedinherited

Denomiator coefficients in delay filter

See also
firCoefficients

◆ iirTemp

template<typename effectsuite_t = effectsuite_t_default>
float* iirTemp = 0
protectedinherited

hold temporary values for iir coeffcient buffer

◆ interpolationTable

template<typename effectsuite_t >
effectsuite_t ** interpolationTable = nullptr
staticprotectedinherited

Table of interpolation values as a 2D array indexed by interpolationTable[pointIndex][alphaIndex]. One instance per DelayEffectBase<effectsuite_t> instantiation (previously a single namespace-scope global shared – and type-mismatched – across every effectsuite_t choice).

◆ interpOrder

template<typename effectsuite_t = effectsuite_t_default>
const int interpOrder = 4
staticprotectedinherited

◆ interpResolution

template<typename effectsuite_t = effectsuite_t_default>
const int interpResolution = 1000
staticprotectedinherited

◆ interpTable

template<typename effectsuite_t = effectsuite_t_default>
effectsuite_t interpTable[order][res]
protectedinherited

◆ is_noise

template<typename effectsuite_t = effectsuite_t_default>
bool is_noise = false
protectedinherited

◆ maxDelayBufferSize

template<typename effectsuite_t = effectsuite_t_default>
int maxDelayBufferSize = 441000
protectedinherited

Maximum number of samples that can be stored in delayBuffer

◆ modMax

template<typename effectsuite_t = effectsuite_t_default>
effectsuite_t modMax = .5
protected

the maximum value of the lowpassed random modulation signal

◆ modMin

template<typename effectsuite_t = effectsuite_t_default>
effectsuite_t modMin = .5
protected

the minimum value of the lowpassed random modulation signal

◆ modNorm

template<typename effectsuite_t = effectsuite_t_default>
effectsuite_t modNorm = 1 / (modMax - modMin)
protected

the normalising factor of the random delay signal

◆ order

template<typename effectsuite_t = effectsuite_t_default>
const int order = 4
staticprotectedinherited

◆ readSpeed

template<typename effectsuite_t = effectsuite_t_default>
const effectsuite_t readSpeed = ((this->readNoise() + 1) * .5) * .0005
protected

◆ res

template<typename effectsuite_t = effectsuite_t_default>
const int res = 100
staticprotectedinherited

◆ rmsBuffer

template<typename effectsuite_t = effectsuite_t_default>
effectsuite_t* rmsBuffer = new effectsuite_t[rmsWindowSize]
protectedinherited

RMS window buffer

◆ rmsBufferIndex

template<typename effectsuite_t = effectsuite_t_default>
int rmsBufferIndex = 0
protectedinherited

current write index of rmsBuffer

◆ rmsWindowSize

template<typename effectsuite_t = effectsuite_t_default>
const int rmsWindowSize = 128
protectedinherited

window size in samples of rms window

◆ sampleRate

template<typename effectsuite_t = effectsuite_t_default>
int sampleRate
inherited

Internal Sample Rate

◆ samplingRate

template<typename effectsuite_t = effectsuite_t_default>
int samplingRate = 0
protectedinherited

◆ swing

template<typename effectsuite_t = effectsuite_t_default>
effectsuite_t swing
protected

swing range of delayed audio index in samples typical maximum swing would be 15 milliseconds (i.e. 0.015*sampleRate)

◆ tableIndex

template<typename effectsuite_t = effectsuite_t_default>
effectsuite_t tableIndex = 0
inherited

current table read index

◆ timeStep

template<typename effectsuite_t = effectsuite_t_default>
effectsuite_t timeStep
inherited

time between samples: 1/sampRate

◆ waveTable

template<typename effectsuite_t = effectsuite_t_default>
effectsuite_t* waveTable = nullptr
inherited

store modulation signal as


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