EnvelopeDetector Class Reference

Envelope follower for dynamics processing. More...

#include <gin_dynamics.h>

Public Types
enum	Mode { peak , ms , rms }
	Envelope detection modes. More...

Public Member Functions
	EnvelopeDetector ()=default
	~EnvelopeDetector ()=default
void	setSampleRate (double f)
void	setParams (float attackS, float holdS, float releaseS, bool analogTC, Mode detect, bool logDetector)
void	setRMSWindow (float seconds)
	Averaging window for the ms and rms modes, in seconds.
void	reset ()
float	process (float input)

Protected Member Functions
void	setAttackTime (float attackS)
void	setHoldTime (float holdS)
void	setReleaseTime (float releaseS)

Protected Attributes
double	sampleRate = 44100.0
Mode	mode = peak
float	attackTime = 0.0f
float	releaseTime = 0.0f
float	envelope = 0.0
float	holdTime = 0.0f
float	holdRemaining = 0.0f
bool	analogTC = false
bool	logDetector = false
float	rmsWindow = 0.010f
float	rmsA = 1.0f
float	rmsB = 0.0f
float	rmsState = 0.0f

Detailed Description

Envelope follower for dynamics processing.

EnvelopeDetector tracks the amplitude envelope of an audio signal using configurable attack, hold, and release times. It supports multiple detection modes (peak, mean-square, RMS) and can use analog-style or digital time constants for natural or precise envelope following.

Key Features:

• Three detection modes: peak, MS, RMS
• Attack, hold, and release time controls
• Analog or digital time constants
• Optional logarithmic detector for dB domain
• Sample-by-sample processing
• Used by compressors, gates, expanders, limiters

The envelope detector is the core component for gain reduction calculations in dynamics processors, providing a smooth representation of signal level over time.

See also

Dynamics, LevelTracker

Member Enumeration Documentation

Mode

enum EnvelopeDetector::Mode

Envelope detection modes.

Determines how the input signal is converted to an envelope value:

• peak: Track the absolute peak value
• ms: Mean square (squared values, more sensitive to transients)
• rms: Root mean square (true RMS level detection)

Enumerator
peak	Peak detection (absolute value).
ms	Mean square detection.
rms	RMS (root mean square) detection.

Constructor & Destructor Documentation

EnvelopeDetector()

EnvelopeDetector::EnvelopeDetector ( )

default

~EnvelopeDetector()

EnvelopeDetector::~EnvelopeDetector ( )

default

Member Function Documentation

setSampleRate()

void EnvelopeDetector::setSampleRate

(

double

f

)

References rmsWindow, sampleRate, and setRMSWindow().

setParams()

void EnvelopeDetector::setParams	(	float	attackS,
		float	holdS,
		float	releaseS,
		bool	analogTC,
		Mode	detect,
		bool	logDetector )

References analogTC, and logDetector.

setRMSWindow()

void EnvelopeDetector::setRMSWindow

(

float

seconds

)

Averaging window for the ms and rms modes, in seconds.

This is what makes RMS detection mean anything: the squared input is averaged over the window before the attack and release stages see it, so the detector responds to how much energy is in the signal rather than to individual samples. Short windows (1 ms) approach peak detection, long ones (50 ms+) ignore transients almost entirely, which is the loudness-following behaviour a bus compressor wants.

Has no effect in peak mode.

Referenced by setSampleRate().

reset()

void EnvelopeDetector::reset

(

)

process()

float EnvelopeDetector::process

(

float

input

)

setAttackTime()

void EnvelopeDetector::setAttackTime ( float attackS )

protected

setHoldTime()

void EnvelopeDetector::setHoldTime ( float holdS )

protected

setReleaseTime()

void EnvelopeDetector::setReleaseTime ( float releaseS )

protected

Member Data Documentation

sampleRate

double EnvelopeDetector::sampleRate = 44100.0

protected

Referenced by setSampleRate().

mode

Mode EnvelopeDetector::mode = peak

protected

attackTime

float EnvelopeDetector::attackTime = 0.0f

protected

releaseTime

float EnvelopeDetector::releaseTime = 0.0f

protected

envelope

float EnvelopeDetector::envelope = 0.0

protected

holdTime

float EnvelopeDetector::holdTime = 0.0f

protected

holdRemaining

float EnvelopeDetector::holdRemaining = 0.0f

protected

analogTC

bool EnvelopeDetector::analogTC = false

protected

Referenced by setParams().

logDetector

bool EnvelopeDetector::logDetector = false

protected

Referenced by setParams().

rmsWindow

float EnvelopeDetector::rmsWindow = 0.010f

protected

Referenced by setSampleRate().

rmsA

float EnvelopeDetector::rmsA = 1.0f

protected

rmsB

float EnvelopeDetector::rmsB = 0.0f

protected

rmsState

float EnvelopeDetector::rmsState = 0.0f

protected

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

• gin_dynamics.h