Graphic Equalizer implemented as an FFT effect: boosts or cuts logarithmically spaced frequency bands (20Hz .. Nyquist) by scaling the magnitude of the bins that fall into each band while leaving their phase untouched. Since this operates directly on the frequency-domain bins rather than an FIR/IIR approximation, band edges are exact and there is no filter ripple. More...

#include <FFTEffects.h>

Inheritance diagram for FFTEqualizer:

Public Member Functions
	FFTEqualizer (AudioOutput &out)

	FFTEqualizer (AudioOutput &out, AudioFFTBase &fft)

	FFTEqualizer (AudioStream &out)

	FFTEqualizer (AudioStream &out, AudioFFTBase &fft)

	FFTEqualizer (Print &out)

	FFTEqualizer (Print &out, AudioFFTBase &fft)

virtual void	addNotifyAudioChange (AudioInfoSupport &bi)
	Adds target to be notified about audio changes.

virtual AudioInfo	audioInfo () override
	provides the actual input AudioInfo

virtual AudioInfo	audioInfoOut ()

virtual int	availableForWrite () override

bool	begin () override

virtual bool	begin (AudioInfo info)

bool	begin (FFTEffectConfig info)

bool	begin (FFTEqualizerConfig cfg)

virtual void	clearNotifyAudioChange ()
	Deletes all change notify subscriptions.

FFTEqualizerConfig	defaultConfig ()

virtual void	end ()

virtual void	flush ()

int	getBandCount ()
	Number of active bands.

float	getBandDB (int band)
	Gets the currently defined gain for a band in dB.

float	getBandFrequency (int band)
	Gets the center frequency of a band in Hz (only valid after begin())

virtual bool	isDeletable ()
	If true we need to release the related memory in the destructor.

bool	isNotifyActive ()
	Checks if the automatic AudioInfo update is active.

virtual	operator bool ()

virtual bool	removeNotifyAudioChange (AudioInfoSupport &bi)
	Removes a target in order not to be notified about audio changes.

virtual void	setAudioInfo (AudioInfo newInfo) override
	Defines the input AudioInfo.

void	setBandCount (int bands)

bool	setBandDB (int band, float gain_db)

bool	setBandGain (int band, float volume)

bool	setBandGains (float volume)
	Sets the same gain for all bands.

void	setNotifyActive (bool flag)
	Deactivate/Reactivate automatic AudioInfo updates: (default is active)

size_t	write (const uint8_t *data, size_t len) override

virtual size_t	write (uint8_t ch) override

virtual void	writeSilence (size_t len)

Protected Member Functions
void	effect (AudioFFTBase &fft) override

void	notifyAudioChange (AudioInfo info)

void	processOutput ()

void	setupBands ()

Static Protected Member Functions
static void	effect_callback (AudioFFTBase &fft)

Protected Attributes
int	_timeout = 10

Vector< int >	band_bin_from

Vector< int >	band_bin_to

Vector< float >	band_center_freq

int	band_count = 10

BufferedWindow	buffered {&hann}

AudioInfo	cfg

StreamCopy	copier

AudioRealFFT	default_fft

AudioFFTConfig	fft_cfg {default_fft.defaultConfig(RXTX_MODE)}

Vector< float >	gains_db

Vector< float >	gains_linear

Hann	hann

bool	is_active = false

bool	is_notify_active = true

Vector< AudioInfoSupport * >	notify_vector

AudioFFTBase *	p_fft = nullptr

Print *	p_out = nullptr

SingleBuffer< uint8_t >	tmp {MAX_SINGLE_CHARS}

int	tmpPos = 0

Detailed Description

Graphic Equalizer implemented as an FFT effect: boosts or cuts logarithmically spaced frequency bands (20Hz .. Nyquist) by scaling the magnitude of the bins that fall into each band while leaving their phase untouched. Since this operates directly on the frequency-domain bins rather than an FIR/IIR approximation, band edges are exact and there is no filter ripple.

Author: phil schatzmann

Constructor & Destructor Documentation

◆ FFTEqualizer() [1/6]

FFTEqualizer ( AudioStream & out )

inline

◆ FFTEqualizer() [2/6]

FFTEqualizer	(	AudioStream &	out,
		AudioFFTBase &	fft
	)

inline

◆ FFTEqualizer() [3/6]

FFTEqualizer ( AudioOutput & out )

inline

◆ FFTEqualizer() [4/6]

FFTEqualizer	(	AudioOutput &	out,
		AudioFFTBase &	fft
	)

inline

◆ FFTEqualizer() [5/6]

FFTEqualizer ( Print & out )

inline

◆ FFTEqualizer() [6/6]

FFTEqualizer	(	Print &	out,
		AudioFFTBase &	fft
	)

inline

Member Function Documentation

◆ addNotifyAudioChange()

virtual void addNotifyAudioChange ( AudioInfoSupport & bi )

inlinevirtualinherited

Adds target to be notified about audio changes.

Reimplemented in CodecNOP, EncodedAudioOutput, EncodedAudioStream, AACDecoderFDK, DecoderBasic, CodecChain, MP3DecoderHelix, MP3DecoderMAD, OggContainerDecoder, RTSPClient< TcpClient, UdpSocket >, Pipeline, and Pipeline::ModifyingStreamAdapter.

◆ audioInfo()

virtual AudioInfo audioInfo ( )

inlineoverridevirtualinherited

provides the actual input AudioInfo

Implements AudioInfoSupport.

Reimplemented in AdapterPrintToAudioOutput, EncodedAudioOutput, and AdapterAudioStreamToAudioOutput.

◆ audioInfoOut()

virtual AudioInfo audioInfoOut ( )

inlinevirtualinherited

provides the actual output AudioInfo: this is usually the same as audioInfo() unless we use a transforming stream

Reimplemented in MP3EncoderShine, PureDataStream, PWMAudioOutput< PWMDriverT >, ChannelFormatConverterStreamT< T >, ChannelFormatConverterStream, NumberFormatConverterStreamT< TFrom, TTo >, NumberFormatConverterStream, FormatConverterStream, Pipeline, ResampleStream, and ResampleStreamT< TInterpolator >.

◆ availableForWrite()

virtual int availableForWrite ( )

inlineoverridevirtualinherited

Reimplemented from Print.

Reimplemented in AudioESP32ULP, RTSPOutput< Platform >, SPIAudioMaster, EncodedAudioOutput, AudioServerEx, AudioSyncWriter, AdapterAudioStreamToAudioOutput, CsvOutput< T >, MemoryOutput, and PWMAudioOutput< PWMDriverT >.

◆ begin() [1/4]

bool begin ( )

inlineoverridevirtual

Reimplemented from FFTEffect.

◆ begin() [2/4]

virtual bool begin ( AudioInfo info )

inlinevirtualinherited

Reimplemented in AudioESP32ULP, RTSPOutput< Platform >, RTTTLOutput< T >, ChannelsSelectOutput, CsvOutput< T >, and EncodedAudioOutput.

◆ begin() [3/4]

bool begin ( FFTEffectConfig info )

inlineinherited

◆ begin() [4/4]

bool begin ( FFTEqualizerConfig cfg )

inline

◆ clearNotifyAudioChange()

virtual void clearNotifyAudioChange ( )

inlinevirtualinherited

Deletes all change notify subscriptions.

Reimplemented in RTSPClient< TcpClient, UdpSocket >.

◆ defaultConfig()

FFTEqualizerConfig defaultConfig ( )

inline

◆ effect()

void effect ( AudioFFTBase & fft )

inlineoverrideprotectedvirtual

Scales the magnitude of the bins in each band by the configured gain, leaving the phase untouched

Implements FFTEffect.

◆ effect_callback()

static void effect_callback ( AudioFFTBase & fft )

inlinestaticprotectedinherited

◆ end()

virtual void end ( )

inlinevirtualinherited

Reimplemented in AudioESP32ULP, AudioServerEx, AudioSyncWriter, RTSPOutput< Platform >, SPIAudioMaster, PitchShiftOutput< T, BufferT >, MetaDataOutput, EncodedAudioOutput, OpusOggWriter, OggContainerOutput, AdapterAudioStreamToAudioOutput, MetaDataFilter, and PWMAudioOutput< PWMDriverT >.

◆ flush()

virtual void flush ( )

inlinevirtualinherited

Reimplemented from Print.

Reimplemented in MultiOutput, and HexDumpOutput.

◆ getBandCount()

int getBandCount ( )

inline

Number of active bands.

◆ getBandDB()

float getBandDB ( int band )

inline

Gets the currently defined gain for a band in dB.

◆ getBandFrequency()

float getBandFrequency ( int band )

inline

Gets the center frequency of a band in Hz (only valid after begin())

◆ isDeletable()

virtual bool isDeletable ( )

inlinevirtualinherited

If true we need to release the related memory in the destructor.

Reimplemented in AdapterPrintToAudioOutput, and AdapterAudioStreamToAudioOutput.

◆ isNotifyActive()

bool isNotifyActive ( )

inlineinherited

Checks if the automatic AudioInfo update is active.

◆ notifyAudioChange()

void notifyAudioChange ( AudioInfo info )

inlineprotectedinherited

◆ operator bool()

virtual operator bool ( )

inlinevirtualinherited

Reimplemented in RTSPOutput< Platform >, EncodedAudioOutput, and AdapterAudioStreamToAudioOutput.

◆ processOutput()

void processOutput ( )

inlineprotectedinherited

◆ removeNotifyAudioChange()

virtual bool removeNotifyAudioChange ( AudioInfoSupport & bi )

inlinevirtualinherited

Removes a target in order not to be notified about audio changes.

Reimplemented in RTSPClient< TcpClient, UdpSocket >.

◆ setAudioInfo()

virtual void setAudioInfo ( AudioInfo info )

inlineoverridevirtualinherited

Defines the input AudioInfo.

Implements AudioInfoSupport.

Reimplemented in ChannelsSelectOutput, AdapterPrintToAudioOutput, MultiOutput, SPIAudioMaster, AdapterAudioStreamToAudioOutput, CsvOutput< T >, PWMAudioOutput< PWMDriverT >, and EncodedAudioOutput.

◆ setBandCount()

void setBandCount ( int bands )

inline

Defines the number of logarithmically spaced bands; call before begin() or before defaultConfig() if you want a non-default band count.

◆ setBandDB()

bool setBandDB	(	int	band,
		float	gain_db
	)

inline

Sets the gain for a band directly in dB (-90 to +12 is a sane range; values are not clamped)

◆ setBandGain()

bool setBandGain	(	int	band,
		float	volume
	)

inline

Sets the gain for a band as a normalized volume (-1.0 to 1.0), mapped to -90dB..+12dB. For deeper cuts/boosts use setBandDB() directly.

◆ setBandGains()

bool setBandGains ( float volume )

inline

Sets the same gain for all bands.

◆ setNotifyActive()

void setNotifyActive ( bool flag )

inlineinherited

Deactivate/Reactivate automatic AudioInfo updates: (default is active)

◆ setupBands()

void setupBands ( )

inlineprotected

Determines the fft bin range and center frequency of each logarithmically spaced band between 20Hz and Nyquist

◆ write() [1/2]

size_t write	(	const uint8_t *	data,
		size_t	len
	)

inlineoverridevirtualinherited

Implements AudioOutput.

◆ write() [2/2]

virtual size_t write ( uint8_t ch )

inlineoverridevirtualinherited

Reimplemented in MetaDataOutput, and MultiOutput.

◆ writeSilence()

virtual void writeSilence ( size_t len )

inlinevirtualinherited

Writes n 0 values (= silence)

Parameters

int tmpPos = 0

protectedinherited

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

src/AudioTools/FFT/FFTEffects.h

Public Member Functions

Protected Member Functions

Static Protected Member Functions

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

◆ FFTEqualizer() [1/6]

◆ FFTEqualizer() [2/6]

◆ FFTEqualizer() [3/6]

◆ FFTEqualizer() [4/6]

◆ FFTEqualizer() [5/6]

◆ FFTEqualizer() [6/6]

Member Function Documentation

◆ addNotifyAudioChange()

◆ audioInfo()

◆ audioInfoOut()

◆ availableForWrite()

◆ begin() [1/4]

◆ begin() [2/4]

◆ begin() [3/4]

◆ begin() [4/4]

◆ clearNotifyAudioChange()

◆ defaultConfig()

◆ effect()

◆ effect_callback()

◆ end()

◆ flush()

◆ getBandCount()

◆ getBandDB()

◆ getBandFrequency()

◆ isDeletable()

◆ isNotifyActive()

◆ notifyAudioChange()

◆ operator bool()

◆ processOutput()

◆ removeNotifyAudioChange()

◆ setAudioInfo()

◆ setBandCount()

◆ setBandDB()

◆ setBandGain()

◆ setBandGains()

◆ setNotifyActive()

◆ setupBands()

◆ write() [1/2]

◆ write() [2/2]

◆ writeSilence()

Member Data Documentation

◆ _timeout

◆ band_bin_from

◆ band_bin_to

◆ band_center_freq

◆ band_count

◆ buffered

◆ cfg

◆ copier

◆ default_fft

◆ fft_cfg

◆ gains_db

◆ gains_linear

◆ hann

◆ is_active

◆ is_notify_active

◆ notify_vector

◆ p_fft

◆ p_out

◆ tmp

◆ tmpPos