Detailed Description

SpectralEqualizer applies frequency-dependent gain correction to address mid-frequency dominance and provide perceptual weighting of audio spectra.

Common use cases:

A-weighting: Emphasize frequencies where human hearing is most sensitive (1-6 kHz)
Mid-scoop: Reduce mid frequencies to balance bass/treble in visual effects
Custom EQ: User-defined per-band gain adjustments

The equalizer operates on frequency bins produced by FrequencyBinMapper and applies configurable gain curves to reshape the spectrum before beat detection and visual processing.

Usage:

SpectralEqualizer eq;
SpectralEqualizerConfig config;
config.curve = EqualizationCurve::AWeighting;
config.numBands = 16;
eq.configure(config);
 
// Process frequency bins from FrequencyBinMapper
vector<float> frequencyBins = ...;  // From mapper.mapBins()
vector<float> equalizedBins(16);
eq.apply(frequencyBins, equalizedBins);

Definition at line 76 of file spectral_equalizer.h.

#include <spectral_equalizer.h>

Collaboration diagram for fl::audio::SpectralEqualizer:

Classes
struct	Stats
	Get statistics (for debugging/monitoring) More...

Public Member Functions
	SpectralEqualizer () FL_NOEXCEPT

	SpectralEqualizer (const SpectralEqualizerConfig &config)

	~SpectralEqualizer () FL_NOEXCEPT

void	apply (span< const float > inputBins, span< float > outputBins) const
	Apply equalization to frequency bins.

void	configure (const SpectralEqualizerConfig &config)
	Configure the spectral equalizer This calculates per-band gain multipliers based on the selected curve.

const SpectralEqualizerConfig &	getConfig () const
	Get current configuration.

span< const float >	getGains () const
	Get current per-band gains.

const Stats &	getStats () const

void	resetStats ()
	Reset statistics.

void	setCustomGains (span< const float > gains)
	Set custom per-band gains (switches to Custom curve)

Private Member Functions
float	applyCompression (float value) const
	Apply dynamic range compression per band.

void	calculateAWeightingGains ()
	Calculate A-weighting gains.

void	calculateFlatGains ()
	Calculate flat gains (all 1.0)

void	calculateGains ()
	Calculate gains based on current curve.

float	calculateMakeupGain (span< const float > inputBins, span< const float > outputBins) const
	Calculate makeup gain to maintain target level.

Private Attributes
SpectralEqualizerConfig	mConfig

vector< float >	mGains
	Per-band gain multipliers.

Stats	mStats

Static Private Attributes
static constexpr float	A_WEIGHTING_16BAND [16]
	A-weighting coefficients for 16-band frequency analysis These approximate the A-weighting curve across logarithmic frequency bins Values emphasize 1-6 kHz range where human hearing is most sensitive.

static constexpr float	A_WEIGHTING_32BAND [32]
	A-weighting coefficients for 32-band frequency analysis.

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

fl/audio/spectral_equalizer.h
fl/audio/spectral_equalizer.cpp.hpp

Detailed Description

Classes

Public Member Functions

Private Member Functions

Private Attributes

Static Private Attributes