edsp::envelope_follower< T > Class Template Reference

This class implements a basic envelope-follower. More...

#include <envelope_follower.hpp>

Public Types
using	value_type = T
using	size_type = std::size_t

Public Member Functions
constexpr	envelope_follower (value_type samplerate, value_type attackTime, value_type releaseTime, bool rectify=false) noexcept
	Creates an EnvelopeFollower object class. More...
constexpr value_type	samplerate () const noexcept
	Returns the sample rate in Hz. More...
constexpr void	set_samplerate (value_type samplerate) noexcept
	Sets the sample rate in Hz and resets the internal parameters. More...
constexpr value_type	attack_time () const noexcept
	Returns the attack time of the first order lowpass in the attack phase. More...
constexpr void	set_attack_time (value_type attackTime) noexcept
	Set the the attack time of the first order lowpass in the attack phase. More...
constexpr value_type	release_time () const noexcept
	Returns the release time of the first order lowpass in the release phase. More...
constexpr void	set_release_time (value_type releaseTime) noexcept
	Set the the release time of the first order lowpass in the attack phase. More...
constexpr bool	rectification () const noexcept
	Checks if the rectification is enabled. More...
constexpr void	set_rectification (bool enabled) noexcept
	Enables the rectification of the output signal. More...
constexpr void	reset () noexcept
	Resets the temporal an internal data. More...
template<typename InIterator , typename OutputIt >
constexpr void	apply (InIterator first, InIterator last, OutputIt d_first)
	Computes the envelope of the element's value in the range [first, last), and stores the result in another range, beginning at d_first. More...

Detailed Description

template<typename T>
class edsp::envelope_follower< T >

This class implements a basic envelope-follower.

The envelope follower takes an high-frequency signal as input and provides an output which is the envelope of the original signal. It is frequently used to detect the amplitude variations of an incoming signal to produce a control signal that resembles those variations.

This class implements a basic Envelope Follower based in a non-symmetric lowpass filter. The output of a low-pass filter can be viewed as a moving average of its input. A minimal envelope generator has an attack period, in which the level of the envelope rises from an initial zero level to a maximum level, followed by a release phase,in which the level falls back to zero. *

Member Typedef Documentation

size_type

template<typename T>

using edsp::envelope_follower< T >::size_type = std::size_t

value_type

template<typename T>

using edsp::envelope_follower< T >::value_type = T

Constructor & Destructor Documentation

envelope_follower()

template<typename T >

constexpr edsp::envelope_follower< T >::envelope_follower ( value_type  samplerate, value_type  attackTime, value_type  releaseTime, bool  rectify = false  )

noexcept

Creates an EnvelopeFollower object class.

Parameters

samplerate	The sample rate in Hz.
attackTime	The attack time of the first order lowpass in the attack phase in msecs.
releaseTime	The release time of the first order lowpass in the attack phase in msecs.
rectify	If true, enables the rectification of the output signal.

Member Function Documentation

apply()

template<typename T >

template<typename InIterator , typename OutputIt >

constexpr void edsp::envelope_follower< T >::apply	(	InIterator	first,
		InIterator	last,
		OutputIt	d_first
	)

Computes the envelope of the element's value in the range [first, last), and stores the result in another range, beginning at d_first.

Parameters

first	Input iterator defining the beginning of the input range.
last	Input iterator defining the ending of the input range.
d_first	Output iterator defining the beginning of the destination range.

attack_time()

template<typename T >

constexpr envelope_follower< T >::value_type edsp::envelope_follower< T >::attack_time ( ) const

noexcept

Returns the attack time of the first order lowpass in the attack phase.

Returns

Attack time in msecs.

rectification()

template<typename T >

constexpr bool edsp::envelope_follower< T >::rectification ( ) const

noexcept

Checks if the rectification is enabled.

Returns

true if the rectification is enabled, false otherwise.

release_time()

template<typename T >

constexpr envelope_follower< T >::value_type edsp::envelope_follower< T >::release_time ( ) const

noexcept

Returns the release time of the first order lowpass in the release phase.

Returns

Release time in msecs.

reset()

template<typename T >

constexpr void edsp::envelope_follower< T >::reset ( )

noexcept

Resets the temporal an internal data.

samplerate()

template<typename T >

constexpr envelope_follower< T >::value_type edsp::envelope_follower< T >::samplerate ( ) const

noexcept

Returns the sample rate in Hz.

Returns

Sample rate in Hz.

set_attack_time()

template<typename T >

constexpr void edsp::envelope_follower< T >::set_attack_time ( value_type  attackTime )

noexcept

Set the the attack time of the first order lowpass in the attack phase.

Parameters

attackTime

Attack time in msecs.

set_rectification()

template<typename T >

constexpr void edsp::envelope_follower< T >::set_rectification ( bool  enabled )

noexcept

Enables the rectification of the output signal.

If the rectification is enabled, the envelope-follower is based on the absolute value of signal

Parameters

enabled

State of the rectification.

set_release_time()

template<typename T >

constexpr void edsp::envelope_follower< T >::set_release_time ( value_type  releaseTime )

noexcept

Set the the release time of the first order lowpass in the attack phase.

Parameters

releaseTime

Release time in msecs.

set_samplerate()

template<typename T >

constexpr void edsp::envelope_follower< T >::set_samplerate ( value_type  samplerate )

noexcept

Sets the sample rate in Hz and resets the internal parameters.

Parameters

samplerate

Sample rate in Hz.

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

• effects/envelope_follower.hpp