dspark::AutoGain< T > Class Template Reference

Block-adaptive automatic gain compensation with SIMD-friendly linear interpolation. More...

#include <AutoGain.h>

Public Types
enum class	Weighting { KWeighted , Flat }
	Level measurement used for the match. More...

Public Member Functions
void	prepare (const AudioSpec &spec)
	Prepares the auto-gain processor.
void	pushReference (AudioBufferView< T > buffer) noexcept
	Snapshots the input level. Must be called BEFORE processing.
void	compensate (AudioBufferView< T > buffer) noexcept
	Measures output level and applies smoothed gain compensation. Must be called AFTER processing.
void	reset () noexcept
	Hard resets the internal state to avoid feedback loops or stale measurements.
void	setWeighting (Weighting w) noexcept
	Selects the level measurement (K-weighted loudness by default). RT-safe.
Weighting	getWeighting () const noexcept
T	getCompensationDb () const noexcept
	Returns the current internal compensation in dB. Useful for UI metering.
void	setMaxCompensation (T dB) noexcept
	Thread-safe assignment of the maximum allowed compensation limit.
void	setSmoothingTime (T ms) noexcept
	Sets the smoothing time constant.
T	getMaxCompensation () const noexcept
T	getSmoothingTime () const noexcept
std::vector< uint8_t >	getState () const
	Serializes the parameter state (setup/UI threads; allocates).
bool	setState (const uint8_t *data, size_t size)
	Restores parameters from a blob (tolerant; rejects foreign ids).

Detailed Description

template<FloatType T>
class dspark::AutoGain< T >

Block-adaptive automatic gain compensation with SIMD-friendly linear interpolation.

Levels are measured across the channels passed to prepare(); channels beyond those are neither measured nor compensated (pass-through), and both calls are no-ops before prepare().

Note on silence: when BOTH the reference and the output are below -90 dB the compensation target is held at 0 dB (nothing meaningful to match). If only the reference is silent while the effect produces output (e.g. a reverb tail), the match pulls the output down, bounded by the max compensation clamp.

Template Parameters

T	Sample type (float or double). Must be lock-free atomic compatible if modified concurrently.

Definition at line 78 of file AutoGain.h.

Member Enumeration Documentation

Weighting

template<FloatType T>

enum class dspark::AutoGain::Weighting

strong

Level measurement used for the match.

Enumerator
KWeighted	ITU-R BS.1770 K-weighting (loudness, LUFS filter). Default.
Flat	Unweighted mean square (plain RMS).

Definition at line 86 of file AutoGain.h.

Member Function Documentation

compensate()

template<FloatType T>

void dspark::AutoGain< T >::compensate ( AudioBufferView< T >  buffer )

inlinenoexcept

Measures output level and applies smoothed gain compensation. Must be called AFTER processing.

Parameters

buffer

Processed audio (modified in-place).

Definition at line 134 of file AutoGain.h.

getCompensationDb()

template<FloatType T>

T dspark::AutoGain< T >::getCompensationDb ( ) const

inlinenoexcept

Returns the current internal compensation in dB. Useful for UI metering.

Safe from any thread: it loads a published atomic word, not the audio thread's working state. The value is the one the last completed compensate() left, so it may be up to one block old.

Returns

Current gain offset in decibels.

Definition at line 221 of file AutoGain.h.

getMaxCompensation()

template<FloatType T>

T dspark::AutoGain< T >::getMaxCompensation ( ) const

inlinenoexcept

Returns

The maximum allowed compensation in dB (positive).

Definition at line 251 of file AutoGain.h.

getSmoothingTime()

template<FloatType T>

T dspark::AutoGain< T >::getSmoothingTime ( ) const

inlinenoexcept

Returns

The smoothing time constant in milliseconds.

Definition at line 257 of file AutoGain.h.

getState()

template<FloatType T>

std::vector< uint8_t > dspark::AutoGain< T >::getState ( ) const

inline

Serializes the parameter state (setup/UI threads; allocates).

Definition at line 263 of file AutoGain.h.

getWeighting()

template<FloatType T>

Weighting dspark::AutoGain< T >::getWeighting ( ) const

inlinenoexcept

Returns

The level measurement in use.

Definition at line 207 of file AutoGain.h.

prepare()

template<FloatType T>

void dspark::AutoGain< T >::prepare ( const AudioSpec &  spec )

inline

Prepares the auto-gain processor.

An invalid spec (non-positive or non-finite fields) is a no-op that keeps the previous state. Allocates the per-channel weighting state.

Parameters

spec	Audio environment specification containing sample rate and channels.

Definition at line 100 of file AutoGain.h.

pushReference()

template<FloatType T>

void dspark::AutoGain< T >::pushReference ( AudioBufferView< T >  buffer )

inlinenoexcept

Snapshots the input level. Must be called BEFORE processing.

An empty view (or one with no prepared channels) keeps the previous reference instead of degrading it.

Parameters

buffer

Input audio (read-only measurement).

Definition at line 121 of file AutoGain.h.

reset()

template<FloatType T>

void dspark::AutoGain< T >::reset ( )

inlinenoexcept

Hard resets the internal state to avoid feedback loops or stale measurements.

Definition at line 189 of file AutoGain.h.

setMaxCompensation()

template<FloatType T>

void dspark::AutoGain< T >::setMaxCompensation ( T  dB )

inlinenoexcept

Thread-safe assignment of the maximum allowed compensation limit.

Parameters

dB	Max gain change in decibels (absolute value used symmetrically). Non-finite values are ignored (a NaN would silently disable the clamp).

Definition at line 231 of file AutoGain.h.

setSmoothingTime()

template<FloatType T>

void dspark::AutoGain< T >::setSmoothingTime ( T  ms )

inlinenoexcept

Sets the smoothing time constant.

Parameters

ms	Smoothing time in milliseconds, floored at 1 ms. Non-finite values are ignored (a NaN would poison the compensation state permanently).

Definition at line 243 of file AutoGain.h.

setState()

template<FloatType T>

bool dspark::AutoGain< T >::setState ( const uint8_t *  data, size_t  size  )

inline

Restores parameters from a blob (tolerant; rejects foreign ids).

Definition at line 275 of file AutoGain.h.

setWeighting()

template<FloatType T>

void dspark::AutoGain< T >::setWeighting ( Weighting  w )

inlinenoexcept

Selects the level measurement (K-weighted loudness by default). RT-safe.

Definition at line 200 of file AutoGain.h.

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

• AutoGain.h