Per-channel peak and RMS envelope follower with lock-free readout. More...

#include <LevelFollower.h>

Public Member Functions
void	prepare (const AudioSpec &spec) noexcept
	Prepares the follower for the given audio environment.

void	setAttackMs (float ms) noexcept
	Sets the attack time for peak metering.

void	setReleaseMs (float ms) noexcept
	Sets the release time for peak metering.

void	setRmsWindowMs (float ms) noexcept
	Sets the integration time constant for RMS metering.

T	getAttackMs () const noexcept
	Returns the peak attack time in milliseconds.

T	getReleaseMs () const noexcept
	Returns the peak release time in milliseconds.

T	getRmsWindowMs () const noexcept
	Returns the RMS integration time constant in milliseconds.

void	reset () noexcept
	Resets all envelope states to zero safely.

void	process (AudioBufferView< const T > buffer) noexcept
	Processes a block of audio and updates level tracking.

T	getPeakLevel (int channel) const noexcept
	Returns the current peak level for the given channel safely.

T	getRmsLevel (int channel) const noexcept
	Returns the current RMS level for the given channel safely.

T	getPeakLevelDb (int channel) const noexcept
	Returns the current peak level in decibels.

T	getRmsLevelDb (int channel) const noexcept
	Returns the current RMS level in decibels (optimized).

Detailed Description

template<FloatType T, int MaxChannels = 16>
class dspark::LevelFollower< T, MaxChannels >

Per-channel peak and RMS envelope follower with lock-free readout.

One-pole envelope followers with a branchless attack/release selector in the hot loop (avoids branch mispredictions on noisy program material; the per-sample recursion itself is inherently serial). Channels beyond the prepared count (or beyond MaxChannels) are not metered. A non-finite input sample would stick in the recursions forever, so the published state is sanitized once per block: the meter recovers on the next block instead of reporting NaN until reset().

Template Parameters

T	Sample type (float or double).
MaxChannels	Maximum number of channels supported.

Definition at line 74 of file LevelFollower.h.

Member Function Documentation

◆ getAttackMs()

template<FloatType T, int MaxChannels = 16>

T dspark::LevelFollower< T, MaxChannels >::getAttackMs ( ) const

inlinenoexcept

Returns the peak attack time in milliseconds.

Definition at line 142 of file LevelFollower.h.

◆ getPeakLevel()

template<FloatType T, int MaxChannels = 16>

T dspark::LevelFollower< T, MaxChannels >::getPeakLevel ( int channel ) const

inlinenoexcept

Returns the current peak level for the given channel safely.

Parameters

channel Channel index (0-based; out-of-range returns 0).

Returns: Peak level (linear, >= 0).

Definition at line 235 of file LevelFollower.h.

◆ getPeakLevelDb()

template<FloatType T, int MaxChannels = 16>

T dspark::LevelFollower< T, MaxChannels >::getPeakLevelDb ( int channel ) const

inlinenoexcept

Returns the current peak level in decibels.

Parameters

channel Channel index (0-based).

Returns: Peak level in dB (floored at -100).

Definition at line 258 of file LevelFollower.h.

◆ getReleaseMs()

template<FloatType T, int MaxChannels = 16>

T dspark::LevelFollower< T, MaxChannels >::getReleaseMs ( ) const

inlinenoexcept

Returns the peak release time in milliseconds.

Definition at line 148 of file LevelFollower.h.

◆ getRmsLevel()

template<FloatType T, int MaxChannels = 16>

T dspark::LevelFollower< T, MaxChannels >::getRmsLevel ( int channel ) const

inlinenoexcept

Returns the current RMS level for the given channel safely.

Parameters

channel Channel index (0-based; out-of-range returns 0).

Returns: RMS level (linear, >= 0).

Definition at line 246 of file LevelFollower.h.

◆ getRmsLevelDb()

template<FloatType T, int MaxChannels = 16>

T dspark::LevelFollower< T, MaxChannels >::getRmsLevelDb ( int channel ) const

inlinenoexcept

Returns the current RMS level in decibels (optimized).

Parameters

channel Channel index (0-based).

Returns: RMS level in dB (floored at -100).

Definition at line 268 of file LevelFollower.h.

◆ getRmsWindowMs()

template<FloatType T, int MaxChannels = 16>

T dspark::LevelFollower< T, MaxChannels >::getRmsWindowMs ( ) const

inlinenoexcept

Returns the RMS integration time constant in milliseconds.

Definition at line 154 of file LevelFollower.h.

◆ prepare()

template<FloatType T, int MaxChannels = 16>

void dspark::LevelFollower< T, MaxChannels >::prepare ( const AudioSpec & spec )

inlinenoexcept

Prepares the follower for the given audio environment.

Recomputes coefficients for the new sample rate and resets all envelope states. An invalid spec (non-positive or non-finite fields) is ignored, keeping the previous state.

Parameters

spec	Audio specification (sample rate, block size, channels).

Definition at line 86 of file LevelFollower.h.

◆ process()

template<FloatType T, int MaxChannels = 16>

void dspark::LevelFollower< T, MaxChannels >::process ( AudioBufferView< const T > buffer )

inlinenoexcept

Processes a block of audio and updates level tracking.

No-op before prepare(). Channels beyond the prepared count are not metered.

Parameters

buffer Read-only audio buffer view.

Definition at line 177 of file LevelFollower.h.

◆ reset()

template<FloatType T, int MaxChannels = 16>

void dspark::LevelFollower< T, MaxChannels >::reset ( )

inlinenoexcept

Resets all envelope states to zero safely.

Definition at line 160 of file LevelFollower.h.

◆ setAttackMs()

template<FloatType T, int MaxChannels = 16>

void dspark::LevelFollower< T, MaxChannels >::setAttackMs ( float ms )

inlinenoexcept

Sets the attack time for peak metering.

Parameters

ms	Attack time in milliseconds (floored to 0.001; non-finite values are ignored).

Definition at line 102 of file LevelFollower.h.

◆ setReleaseMs()

template<FloatType T, int MaxChannels = 16>

void dspark::LevelFollower< T, MaxChannels >::setReleaseMs ( float ms )

inlinenoexcept

Sets the release time for peak metering.

Parameters

ms	Release time in milliseconds (floored to 0.001; non-finite values are ignored).

Definition at line 115 of file LevelFollower.h.

◆ setRmsWindowMs()

template<FloatType T, int MaxChannels = 16>

void dspark::LevelFollower< T, MaxChannels >::setRmsWindowMs ( float ms )

inlinenoexcept

Sets the integration time constant for RMS metering.

The RMS detector is a one-pole exponential integrator over the squared signal; this is its time constant (63% settling on a level step), not the length of a rectangular window.

Parameters

ms	Time constant in milliseconds (floored to 0.001; non-finite values are ignored).

Definition at line 133 of file LevelFollower.h.

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

Analysis/LevelFollower.h

Public Member Functions

Detailed Description

Member Function Documentation

◆ getAttackMs()

◆ getPeakLevel()

◆ getPeakLevelDb()

◆ getReleaseMs()

◆ getRmsLevel()

◆ getRmsLevelDb()

◆ getRmsWindowMs()

◆ prepare()

◆ process()

◆ reset()

◆ setAttackMs()

◆ setReleaseMs()

◆ setRmsWindowMs()