juce::dsp::BallisticsFilter< SampleType > Class Template Reference

A processor to apply standard attack / release ballistics to an input signal. More...

#include <juce_BallisticsFilter.h>

Collaboration diagram for juce::dsp::BallisticsFilter< SampleType >:

Public Types
using	LevelCalculationType = BallisticsFilterLevelCalculationType

Public Member Functions
	BallisticsFilter ()
	Constructor. More...
void	prepare (const ProcessSpec &spec)
	Initialises the filter. More...
template<typename ProcessContext >
void	process (const ProcessContext &context) noexcept
	Processes the input and output samples supplied in the processing context. More...
SampleType	processSample (int channel, SampleType inputValue)
	Processes one sample at a time on a given channel. More...
void	reset ()
	Resets the internal state variables of the filter. More...
void	reset (SampleType initialValue)
	Resets the internal state variables of the filter to the given initial value. More...
void	setAttackTime (SampleType attackTimeMs)
	Sets the attack time in ms. More...
void	setLevelCalculationType (LevelCalculationType newCalculationType)
	Sets how the filter levels are calculated. More...
void	setReleaseTime (SampleType releaseTimeMs)
	Sets the release time in ms. More...
void	snapToZero () noexcept
	Ensure that the state variables are rounded to zero if the state variables are denormals. More...

Private Member Functions
SampleType	calculateLimitedCte (SampleType) const noexcept

Private Attributes
SampleType	attackTime = 1.0
SampleType	cteAT = 0.0
SampleType	cteRL = 0.0
double	expFactor = -0.142
LevelCalculationType	levelType = LevelCalculationType::peak
SampleType	releaseTime = 100.0
double	sampleRate = 44100.0
std::vector< SampleType >	yold

Detailed Description

template<typename SampleType>
class juce::dsp::BallisticsFilter< SampleType >

A processor to apply standard attack / release ballistics to an input signal.

This is useful in dynamics processors, envelope followers, modulated audio effects and for smoothing animation in data visualisation.

@tags{DSP}

Member Typedef Documentation

LevelCalculationType

template<typename SampleType >

using juce::dsp::BallisticsFilter< SampleType >::LevelCalculationType = BallisticsFilterLevelCalculationType

Constructor & Destructor Documentation

BallisticsFilter()

template<typename SampleType >

juce::dsp::BallisticsFilter< SampleType >::BallisticsFilter

(

)

Constructor.

Member Function Documentation

calculateLimitedCte()

template<typename SampleType >

SampleType juce::dsp::BallisticsFilter< SampleType >::calculateLimitedCte ( SampleType  ) const

privatenoexcept

prepare()

template<typename SampleType >

void juce::dsp::BallisticsFilter< SampleType >::prepare

(

const ProcessSpec &

spec

)

Initialises the filter.

process()

template<typename SampleType >

template<typename ProcessContext >

void juce::dsp::BallisticsFilter< SampleType >::process ( const ProcessContext &  context )

inlinenoexcept

Processes the input and output samples supplied in the processing context.

References jassert, juce::dsp::BallisticsFilter< SampleType >::processSample(), juce::dsp::BallisticsFilter< SampleType >::snapToZero(), and juce::dsp::BallisticsFilter< SampleType >::yold.

processSample()

template<typename SampleType >

SampleType juce::dsp::BallisticsFilter< SampleType >::processSample	(	int	channel,
		SampleType	inputValue
	)

Processes one sample at a time on a given channel.

Referenced by juce::dsp::BallisticsFilter< SampleType >::process().

reset() [1/2]

template<typename SampleType >

void juce::dsp::BallisticsFilter< SampleType >::reset

(

)

Resets the internal state variables of the filter.

reset() [2/2]

template<typename SampleType >

void juce::dsp::BallisticsFilter< SampleType >::reset

(

SampleType

initialValue

)

Resets the internal state variables of the filter to the given initial value.

setAttackTime()

template<typename SampleType >

void juce::dsp::BallisticsFilter< SampleType >::setAttackTime

(

SampleType

attackTimeMs

)

Sets the attack time in ms.

Attack times less than 0.001 ms will be snapped to zero and very long attack times will eventually saturate depending on the numerical precision used.

setLevelCalculationType()

template<typename SampleType >

void juce::dsp::BallisticsFilter< SampleType >::setLevelCalculationType

(

LevelCalculationType

newCalculationType

)

Sets how the filter levels are calculated.

Level calculation in digital envelope followers is usually performed using peak detection with a rectifier function (like std::abs) and filtering, which returns an envelope dependant on the peak or maximum values of the signal amplitude.

To perform an estimation of the average value of the signal you can use an RMS (root mean squared) implementation of the ballistics filter instead. This is useful in some compressor and noise-gate designs, or in specific types of volume meters.

setReleaseTime()

template<typename SampleType >

void juce::dsp::BallisticsFilter< SampleType >::setReleaseTime

(

SampleType

releaseTimeMs

)

Sets the release time in ms.

Release times less than 0.001 ms will be snapped to zero and very long release times will eventually saturate depending on the numerical precision used.

snapToZero()

template<typename SampleType >

void juce::dsp::BallisticsFilter< SampleType >::snapToZero ( )

noexcept

Ensure that the state variables are rounded to zero if the state variables are denormals.

This is only needed if you are doing sample by sample processing.

Referenced by juce::dsp::BallisticsFilter< SampleType >::process().

Member Data Documentation

attackTime

template<typename SampleType >

SampleType juce::dsp::BallisticsFilter< SampleType >::attackTime = 1.0

private

cteAT

template<typename SampleType >

SampleType juce::dsp::BallisticsFilter< SampleType >::cteAT = 0.0

private

cteRL

template<typename SampleType >

SampleType juce::dsp::BallisticsFilter< SampleType >::cteRL = 0.0

private

expFactor

template<typename SampleType >

double juce::dsp::BallisticsFilter< SampleType >::expFactor = -0.142

private

levelType

template<typename SampleType >

LevelCalculationType juce::dsp::BallisticsFilter< SampleType >::levelType = LevelCalculationType::peak

private

releaseTime

template<typename SampleType >

SampleType juce::dsp::BallisticsFilter< SampleType >::releaseTime = 100.0

private

sampleRate

template<typename SampleType >

double juce::dsp::BallisticsFilter< SampleType >::sampleRate = 44100.0

private

yold

template<typename SampleType >

std::vector<SampleType> juce::dsp::BallisticsFilter< SampleType >::yold

private

Referenced by juce::dsp::BallisticsFilter< SampleType >::process().

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

• juce_BallisticsFilter.h