pulp::signal::VcaT< SampleType > Class Template Reference

Voltage-controlled amplifier. More...

#include <vca.hpp>

Public Types
using	Response = VcaResponse

Public Member Functions
void	prepare (SampleType sample_rate)
void	set_response (Response r)
Response	response () const
void	set_range_db (double db)
double	range_db () const
void	set_lag_ms (double ms)
void	reset (SampleType control=SampleType{0})
SampleType	gain_for (SampleType control) const
	Static response curve, without the lag.
SampleType	next_gain (SampleType control)
	Advance the lag by one sample and return the gain that would be applied.
SampleType	process (SampleType input, SampleType control)
SampleType	control () const
	The lagged control value, for metering or for driving a second stage from the same conditioned control.

Static Public Attributes
static constexpr double	kMinRangeDb = 12.0
	Depth of the equal-dB exponential response.
static constexpr double	kMaxRangeDb = 120.0
static constexpr double	kDefaultRangeDb = 60.0
static constexpr double	kDefaultLagMs = 1.0
	Default control lag.

Detailed Description

template<typename SampleType = float>
class pulp::signal::VcaT< SampleType >

Voltage-controlled amplifier.

The exponential response is g = (e^(k*c) - 1) / (e^k - 1) with k = 4.6, which spans about 40 dB — enough that the bottom of the control range is perceptually silent without the numerical hazards of an actual log curve. Both responses are exactly 0 at control 0 and exactly 1 at control 1; unity at full is a series law, so a VCA left wide open is bit-transparent rather than approximately transparent.

Member Typedef Documentation

Response

template<typename SampleType = float>

using pulp::signal::VcaT< SampleType >::Response = VcaResponse

Member Function Documentation

control()

template<typename SampleType = float>

SampleType pulp::signal::VcaT< SampleType >::control ( ) const

inline

The lagged control value, for metering or for driving a second stage from the same conditioned control.

gain_for()

template<typename SampleType = float>

SampleType pulp::signal::VcaT< SampleType >::gain_for ( SampleType control ) const

inline

Static response curve, without the lag.

Exposed so a UI can draw the same curve the audio path uses.

next_gain()

template<typename SampleType = float>

SampleType pulp::signal::VcaT< SampleType >::next_gain ( SampleType control )

inline

Advance the lag by one sample and return the gain that would be applied.

prepare()

template<typename SampleType = float>

void pulp::signal::VcaT< SampleType >::prepare ( SampleType sample_rate )

inline

process()

template<typename SampleType = float>

SampleType pulp::signal::VcaT< SampleType >::process ( SampleType input, SampleType control )

inline

range_db()

template<typename SampleType = float>

double pulp::signal::VcaT< SampleType >::range_db ( ) const

inline

reset()

template<typename SampleType = float>

void pulp::signal::VcaT< SampleType >::reset ( SampleType control = SampleType{0} )

inline

response()

template<typename SampleType = float>

Response pulp::signal::VcaT< SampleType >::response ( ) const

inline

set_lag_ms()

template<typename SampleType = float>

void pulp::signal::VcaT< SampleType >::set_lag_ms ( double ms )

inline

set_range_db()

template<typename SampleType = float>

void pulp::signal::VcaT< SampleType >::set_range_db ( double db )

inline

set_response()

template<typename SampleType = float>

void pulp::signal::VcaT< SampleType >::set_response ( Response r )

inline

Member Data Documentation

kDefaultLagMs

template<typename SampleType = float>

double pulp::signal::VcaT< SampleType >::kDefaultLagMs = 1.0

staticconstexpr

Default control lag.

Long enough to kill the click from a hard-switched gate, short enough that a percussive envelope keeps its transient.

kDefaultRangeDb

template<typename SampleType = float>

double pulp::signal::VcaT< SampleType >::kDefaultRangeDb = 60.0

staticconstexpr

kMaxRangeDb

template<typename SampleType = float>

double pulp::signal::VcaT< SampleType >::kMaxRangeDb = 120.0

staticconstexpr

kMinRangeDb

template<typename SampleType = float>

double pulp::signal::VcaT< SampleType >::kMinRangeDb = 12.0

staticconstexpr

Depth of the equal-dB exponential response.

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

• /home/runner/work/pulp/pulp/core/signal/include/pulp/signal/vca.hpp