Executes FFT using audio data privded by write() and/or an inverse FFT where the samples are made available via readBytes(). The Driver which is passed in the constructor selects a specifc FFT implementation. More...

#include <AudioFFT.h>

Inheritance diagram for AudioFFTBase:

Classes
struct	MelFilter
	One triangular mel filter: weights for bins [start_bin, start_bin+count). More...

Public Member Functions
	AudioFFTBase (const AudioFFTBase &)=delete
	AudioFFTBase (FFTDriver *driver)
	~AudioFFTBase ()
virtual void	addNotifyAudioChange (AudioInfoSupport &bi)
	Adds target to be notified about audio changes.
virtual void	addNotifyAudioChange (AudioInfoSupport &bi)
	Adds target to be notified about audio changes.
virtual AudioInfo	audioInfo () override
	provides the actual input AudioInfo
virtual AudioInfo	audioInfo () override
	provides the actual input AudioInfo
virtual AudioInfo	audioInfoOut ()
virtual AudioInfo	audioInfoOut ()
int	available () override
	Data available for reverse fft.
int	availableForWrite () override
	We try to fill the buffer at once.
bool	begin () override
	starts the processing
bool	begin (AudioFFTConfig info)
	starts the processing
void	clearBins ()
	clears the fft data
virtual void	clearNotifyAudioChange ()
	Deletes all change notify subscriptions.
virtual void	clearNotifyAudioChange ()
	Deletes all change notify subscriptions.
AudioFFTConfig &	config ()
	Provides the actual configuration.
AudioFFTConfig	defaultConfig (RxTxMode mode=TX_MODE)
	Provides the default configuration.
FFTDriver *	driver ()
void	end () override
	Release the allocated memory.
virtual void	flush () override
virtual void	flush () override
float	frequency (int bin)
	Determines the frequency of the indicated bin.
int	frequencyToBin (int freq)
	Determine the bin number from the frequency.
bool	fromMEL (float *values, int n_bins, float min_freq=0.0f, float max_freq=0.0f)
	Convert MEL spectrum back to linear frequency spectrum, using the same (cached) filterbank as toMEL().
bool	getBin (int pos, FFTBin &bin)
	gets the value of a bin
bool	isNotifyActive ()
	Checks if the automatic AudioInfo update is active.
bool	isNotifyActive ()
	Checks if the automatic AudioInfo update is active.
int	length ()
	The number of samples.
float	magnitude (int bin)
float	magnitudeFast (int bin)
float *	magnitudes ()
float *	magnitudesFast ()
	operator bool () override
AudioFFTBase &	operator= (const AudioFFTBase &)=delete
float	phase (int bin)
	calculates the phase
size_t	readBytes (uint8_t *data, size_t len) override
	Provides the result of a reverse FFT.
virtual size_t	readSilence (uint8_t *buffer, size_t length)
	Source to generate silence: just sets the buffer to 0.
virtual size_t	readSilence (uint8_t *buffer, size_t length)
	Source to generate silence: just sets the buffer to 0.
template<typename T>
T &	reference ()
	Provides the reference pointer.
virtual bool	removeNotifyAudioChange (AudioInfoSupport &bi)
	Removes a target in order not to be notified about audio changes.
virtual bool	removeNotifyAudioChange (AudioInfoSupport &bi)
	Removes a target in order not to be notified about audio changes.
void	reset ()
	Just resets the current_pos e.g. to start a new cycle.
AudioFFTResult	result ()
	Determines the result values in the max magnitude bin.
template<int N>
void	resultArray (AudioFFTResult(&result)[N])
	Determines the N biggest result values.
unsigned long	resultTime ()
unsigned long	resultTimeBegin ()
	time before the fft
virtual void	setAudioInfo (AudioInfo newInfo) override
	Defines the input AudioInfo.
void	setAudioInfo (AudioInfo info) override
	Notify change of audio information.
bool	setBin (int idx, float real, float img)
	sets the value of a bin
bool	setBin (int pos, FFTBin &bin)
	sets the value of a bin
void	setNotifyActive (bool flag)
	Deactivate/Reactivate automatic AudioInfo updates: (default is active).
void	setNotifyActive (bool flag)
	Deactivate/Reactivate automatic AudioInfo updates: (default is active).
void	setWriteBufferSize (int size)
void	setWriteBufferSize (int size)
int	size ()
	The number of bins used by the FFT which are relevant for the result.
float *	toMEL (int n_bins, float min_freq=0.0f, float max_freq=0.0f, bool power=false)
virtual size_t	write (uint8_t ch) override
size_t	write (const uint8_t *data, size_t len) override
	Provide the audio data as FFT input.
virtual void	writeSilence (size_t len)
	Writes len bytes of silence (=0).
virtual void	writeSilence (size_t len)
	Writes len bytes of silence (=0).

Protected Member Functions
int	bytesPerSample ()
template<typename T>
void	fft ()
template<int N>
void	insertSorted (AudioFFTResult(&result)[N], AudioFFTResult tmp)
	make sure that we do not reuse already found results
bool	isPowerOfTwo (uint16_t x)
virtual int	not_supported (int out, const char *msg="")
virtual int	not_supported (int out, const char *msg="")
void	notifyAudioChange (AudioInfo info)
void	notifyAudioChange (AudioInfo info)
template<typename T>
void	processSamples (const void *data, size_t count)
template<typename T>
void	processStrideBuffer ()
	FFT of the full stride buffer, then drop stride samples.
void	refillReadBuffer ()
	Refill small read buffer (e.g. 8 bytes) to avoid single byte reads when calling read().
void	refillReadBuffer ()
	Refill small read buffer (e.g. 8 bytes) to avoid single byte reads when calling read().
void	rfft ()
	reverse fft
void	rfftWriteData (BaseBuffer< uint8_t > &data)
	write reverse fft result to buffer to make it available for readBytes
bool	updateMelFilterbank (int n_bins, float min_freq, float max_freq)
	(Re)builds the cached sparse filterbank if any parameter changed
template<typename T>
T	windowedSample (T sample, int pos)
template<typename T>
void	writeIFFT (float *data, int len)
bool	writeStrideBuffer (uint8_t *buffer, size_t len)

Static Protected Member Functions
static float	hzToMel (float hz)
static float	melToHz (float mel)

Protected Attributes
int	_timeout = 10
int	bins = 0
AudioFFTConfig	cfg
int	current_pos = 0
bool	has_rfft_data = false
AudioInfo	info
bool	is_notify_active = true
Vector< float >	l_magnitudes {0}
Vector< float >	mel_bins {0}
Vector< MelFilter >	mel_filters {0}
int	mel_length = 0
float	mel_max_freq = -1.0f
float	mel_min_freq = -1.0f
int	mel_n_bins = 0
int	mel_sample_rate = 0
Vector< float >	mel_weights {0}
Vector< AudioInfoSupport * >	notify_vector
FFTDriver *	p_driver = nullptr
FFTInverseOverlapAdder	rfft_add {0}
RingBuffer< uint8_t >	rfft_data {0}
Vector< float >	step_data {0}
SingleBuffer< uint8_t >	stride_buffer {0}
unsigned long	timestamp = 0l
unsigned long	timestamp_begin = 0l
RingBuffer< uint8_t >	tmp_in {0}
RingBuffer< uint8_t >	tmp_out {0}
int	write_buffer_size = 8

Detailed Description

Executes FFT using audio data privded by write() and/or an inverse FFT where the samples are made available via readBytes(). The Driver which is passed in the constructor selects a specifc FFT implementation.

Author: Phil Schatzmann

Copyright: GPLv3

Constructor & Destructor Documentation

◆ AudioFFTBase() [1/2]

AudioFFTBase ( FFTDriver * driver )

inline

Default Constructor. The len needs to be of the power of 2 (e.g. 512, 1024, 2048, 4096, 8192) Takes ownership of the driver (allocated with new), which is deleted together with this object

◆ AudioFFTBase() [2/2]

AudioFFTBase ( const AudioFFTBase & )

delete

◆ ~AudioFFTBase()

~AudioFFTBase ( )

inline

Member Function Documentation

◆ addNotifyAudioChange() [1/2]

virtual void addNotifyAudioChange ( AudioInfoSupport & bi )

inlinevirtualinherited

Adds target to be notified about audio changes.

Reimplemented in CodecNOP, CodecNOP, EncodedAudioOutput, and EncodedAudioStream.

◆ addNotifyAudioChange() [2/2]

virtual void addNotifyAudioChange ( AudioInfoSupport & bi )

inlinevirtualinherited

Adds target to be notified about audio changes.

Reimplemented in CodecNOP, CodecNOP, EncodedAudioOutput, and EncodedAudioStream.

◆ audioInfo() [1/2]

virtual AudioInfo audioInfo ( )

inlineoverridevirtualinherited

◆ audioInfo() [2/2]

virtual AudioInfo audioInfo ( )

inlineoverridevirtualinherited

◆ audioInfoOut() [1/2]

virtual AudioInfo audioInfoOut ( )

inlinevirtualinherited

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

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

◆ audioInfoOut() [2/2]

virtual AudioInfo audioInfoOut ( )

inlinevirtualinherited

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

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

◆ available()

int available ( )

inlineoverridevirtual

Data available for reverse fft.

Reimplemented from BaseStream.

◆ availableForWrite()

int availableForWrite ( )

inlineoverridevirtual

We try to fill the buffer at once.

Reimplemented from BaseStream.

◆ begin() [1/2]

bool begin ( )

inlineoverridevirtual

starts the processing

Reimplemented from BaseStream.

◆ begin() [2/2]

bool begin ( AudioFFTConfig info )

inline

starts the processing

◆ bytesPerSample()

int bytesPerSample ( )

inlineprotected

bytes per sample in the audio data: 24 bit samples use the int24_t representation (4 bytes unless USE_3BYTE_INT24 is defined)

◆ clearBins()

void clearBins ( )

inline

clears the fft data

◆ clearNotifyAudioChange() [1/2]

virtual void clearNotifyAudioChange ( )

inlinevirtualinherited

Deletes all change notify subscriptions.

Reimplemented in RTSPClient< TcpClient, UdpSocket >, RTSPClient< EthernetClient, EthernetUDP >, and RTSPClient< WiFiClient, WiFiUDP >.

◆ clearNotifyAudioChange() [2/2]

virtual void clearNotifyAudioChange ( )

inlinevirtualinherited

Deletes all change notify subscriptions.

Reimplemented in RTSPClient< TcpClient, UdpSocket >, RTSPClient< EthernetClient, EthernetUDP >, and RTSPClient< WiFiClient, WiFiUDP >.

◆ config()

AudioFFTConfig & config ( )

inline

Provides the actual configuration.

◆ defaultConfig()

AudioFFTConfig defaultConfig ( RxTxMode mode = TX_MODE )

inline

Provides the default configuration.

◆ driver()

FFTDriver * driver ( )

inline

provides access to the FFTDriver which implements the basic FFT functionality

◆ end()

void end ( )

inlineoverridevirtual

Release the allocated memory.

Reimplemented from BaseStream.

◆ fft()

template<typename T>

void fft ( )

inlineprotected

◆ flush() [1/2]

virtual void flush ( )

inlineoverridevirtualinherited

Reimplemented from Print.

Reimplemented in AudioStreamWrapper, AudioStreamWrapper, BufferedStream, BufferedStream, EncodedAudioStream, FilteredStream< T, TF >, FilteredStream< T, TF >, FilteredStream< int16_t, int16_t >, GeneratedSoundStream< T >, GeneratedSoundStream< T >, GeneratedSoundStream< int16_t >, MemoryStream, MemoryStream, QueueStream< T >, QueueStream< T >, QueueStream< uint8_t >, ReformatBaseStream, RingBufferStream, RingBufferStream, TimedStream, AudioEffectStream, AudioEffectStreamT< T >, AudioStreamWrapper, AutomaticGainControlStream, BufferedStream, BufferedTaskStream, EncodedAudioStream, Equalizer3BandsPerChannelT< T >, Equalizer3BandsPerChannelT< float >, Equalizer3BandsT< T >, Equalizer3BandsT< float >, EqualizerNBands< SampleT, AccT, NUM_TAPS, NUM_BANDS >, FadeStream, FilteredStream< T, TF >, GeneratedSoundStream< T >, I2SStream, MeasuringStream, MemoryStream, Pipeline::ModifyingStreamAdapter, PureDataStream, QualityAnalysisStream, QueueStream< T >, ReformatBaseStream, ResampleStream, RingBufferStream, SupportedRatesStream, TimedStream, URLStream, URLStreamBufferedT< T >, URLStreamBufferedT< ICYStream >, URLStreamBufferedT< ICYStreamESP32 >, URLStreamBufferedT< URLStream >, URLStreamBufferedT< URLStreamESP32 >, and VolumeStream.

◆ flush() [2/2]

virtual void flush ( )

inlineoverridevirtualinherited

Reimplemented from Print.

Reimplemented in AudioStreamWrapper, AudioStreamWrapper, BufferedStream, BufferedStream, EncodedAudioStream, FilteredStream< T, TF >, FilteredStream< T, TF >, FilteredStream< int16_t, int16_t >, GeneratedSoundStream< T >, GeneratedSoundStream< T >, GeneratedSoundStream< int16_t >, MemoryStream, MemoryStream, QueueStream< T >, QueueStream< T >, QueueStream< uint8_t >, ReformatBaseStream, RingBufferStream, RingBufferStream, TimedStream, AudioEffectStream, AudioEffectStreamT< T >, AudioStreamWrapper, AutomaticGainControlStream, BufferedStream, BufferedTaskStream, EncodedAudioStream, Equalizer3BandsPerChannelT< T >, Equalizer3BandsPerChannelT< float >, Equalizer3BandsT< T >, Equalizer3BandsT< float >, EqualizerNBands< SampleT, AccT, NUM_TAPS, NUM_BANDS >, FadeStream, FilteredStream< T, TF >, GeneratedSoundStream< T >, I2SStream, MeasuringStream, MemoryStream, Pipeline::ModifyingStreamAdapter, PureDataStream, QualityAnalysisStream, QueueStream< T >, ReformatBaseStream, ResampleStream, RingBufferStream, SupportedRatesStream, TimedStream, URLStream, URLStreamBufferedT< T >, URLStreamBufferedT< ICYStream >, URLStreamBufferedT< ICYStreamESP32 >, URLStreamBufferedT< URLStream >, URLStreamBufferedT< URLStreamESP32 >, and VolumeStream.

◆ frequency()

float frequency ( int bin )

inline

Determines the frequency of the indicated bin.

◆ frequencyToBin()

int frequencyToBin ( int freq )

inline

Determine the bin number from the frequency.

◆ fromMEL()

bool fromMEL	(	float *	values,
		int	n_bins,
		float	min_freq = 0.0f,
		float	max_freq = 0.0f )

inline

Convert MEL spectrum back to linear frequency spectrum, using the same (cached) filterbank as toMEL().

Parameters

values	Pointer to MEL spectrum values
n_bins	Number of MEL bins

Returns: bool Success status

◆ getBin()

bool getBin	(	int	pos,
		FFTBin &	bin )

inline

gets the value of a bin

◆ hzToMel()

float hzToMel ( float hz )

inlinestaticprotected

◆ insertSorted()

template<int N>

void insertSorted	(	AudioFFTResult(&)	result[N],
		AudioFFTResult	tmp )

inlineprotected

make sure that we do not reuse already found results

◆ isNotifyActive() [1/2]

bool isNotifyActive ( )

inlineinherited

Checks if the automatic AudioInfo update is active.

◆ isNotifyActive() [2/2]

bool isNotifyActive ( )

inlineinherited

Checks if the automatic AudioInfo update is active.

◆ isPowerOfTwo()

bool isPowerOfTwo ( uint16_t x )

inlineprotected

◆ length()

int length ( )

inline

The number of samples.

◆ magnitude()

float magnitude ( int bin )

inline

Calculates the magnitude of the fft result to determine the max value (bin is 0 to size())

◆ magnitudeFast()

float magnitudeFast ( int bin )

inline

◆ magnitudes()

float * magnitudes ( )

inline

Provides the magnitudes as array of size size(). Please note that this method is allocating additinal memory!

◆ magnitudesFast()

float * magnitudesFast ( )

inline

Provides the magnitudes w/o calling the square root function as array of size size(). Please note that this method is allocating additinal memory!

◆ melToHz()

float melToHz ( float mel )

inlinestaticprotected

◆ not_supported() [1/2]

virtual int not_supported	(	int	out,
		const char *	msg = "" )

inlineprotectedvirtualinherited

◆ not_supported() [2/2]

virtual int not_supported	(	int	out,
		const char *	msg = "" )

inlineprotectedvirtualinherited

◆ notifyAudioChange() [1/2]

void notifyAudioChange ( AudioInfo info )

inlineprotectedinherited

◆ notifyAudioChange() [2/2]

void notifyAudioChange ( AudioInfo info )

inlineprotectedinherited

◆ operator bool()

operator bool ( )

inlineoverridevirtual

Reimplemented from AudioStream.

◆ operator=()

AudioFFTBase & operator= ( const AudioFFTBase & )

delete

◆ phase()

float phase ( int bin )

inline

calculates the phase

◆ processSamples()

template<typename T>

void processSamples	(	const void *	data,
		size_t	count )

inlineprotected

◆ processStrideBuffer()

template<typename T>

void processStrideBuffer ( )

inlineprotected

FFT of the full stride buffer, then drop stride samples.

◆ readBytes()

size_t readBytes	(	uint8_t *	data,
		size_t	len )

inlineoverridevirtual

Provides the result of a reverse FFT.

Reimplemented from AudioStream.

◆ readSilence() [1/2]

virtual size_t readSilence	(	uint8_t *	buffer,
		size_t	length )

inlinevirtualinherited

Source to generate silence: just sets the buffer to 0.

◆ readSilence() [2/2]

virtual size_t readSilence	(	uint8_t *	buffer,
		size_t	length )

inlinevirtualinherited

Source to generate silence: just sets the buffer to 0.

◆ reference()

template<typename T>

T & reference ( )

inline

Provides the reference pointer.

◆ refillReadBuffer() [1/2]

void refillReadBuffer ( )

inlineprotectedinherited

Refill small read buffer (e.g. 8 bytes) to avoid single byte reads when calling read().

◆ refillReadBuffer() [2/2]

void refillReadBuffer ( )

inlineprotectedinherited

Refill small read buffer (e.g. 8 bytes) to avoid single byte reads when calling read().

◆ removeNotifyAudioChange() [1/2]

virtual bool removeNotifyAudioChange ( AudioInfoSupport & bi )

inlinevirtualinherited

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

◆ removeNotifyAudioChange() [2/2]

virtual bool removeNotifyAudioChange ( AudioInfoSupport & bi )

inlinevirtualinherited

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

◆ reset()

void reset ( )

inline

Just resets the current_pos e.g. to start a new cycle.

◆ result()

AudioFFTResult result ( )

inline

Determines the result values in the max magnitude bin.

◆ resultArray()

template<int N>

void resultArray ( AudioFFTResult(&) result[N] )

inline

Determines the N biggest result values.

◆ resultTime()

unsigned long resultTime ( )

inline

time after the fft: time when the last result was provided - you can poll this to check if we have a new result

◆ resultTimeBegin()

unsigned long resultTimeBegin ( )

inline

time before the fft

◆ rfft()

void rfft ( )

inlineprotected

reverse fft

◆ rfftWriteData()

void rfftWriteData ( BaseBuffer< uint8_t > & data )

inlineprotected

write reverse fft result to buffer to make it available for readBytes

◆ setAudioInfo() [1/2]

virtual void setAudioInfo ( AudioInfo info )

inlineoverridevirtualinherited

Defines the input AudioInfo.

Implements AudioInfoSupport.

Reimplemented in AdapterAudioOutputToAudioStream, AudioInputMonitor, AudioInputMonitor, CallbackStream, CallbackStream, EncodedAudioStream, GeneratedSoundStream< T >, GeneratedSoundStream< T >, GeneratedSoundStream< int16_t >, ProgressStream, ProgressStream, TimedStream, TimerCallbackAudioStream, TimerCallbackAudioStream, VolumeMeter, and VolumeMeter.

◆ setAudioInfo() [2/2]

void setAudioInfo ( AudioInfo info )

inlineoverride

Notify change of audio information.

◆ setBin() [1/2]

bool setBin	(	int	idx,
		float	real,
		float	img )

inline

sets the value of a bin

◆ setBin() [2/2]

bool setBin	(	int	pos,
		FFTBin &	bin )

inline

sets the value of a bin

◆ setNotifyActive() [1/2]

void setNotifyActive ( bool flag )

inlineinherited

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

◆ setNotifyActive() [2/2]

void setNotifyActive ( bool flag )

inlineinherited

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

◆ setWriteBufferSize() [1/2]

void setWriteBufferSize ( int size )

inlineinherited

◆ setWriteBufferSize() [2/2]

void setWriteBufferSize ( int size )

inlineinherited

◆ size()

int size ( )

inline

The number of bins used by the FFT which are relevant for the result.

◆ toMEL()

float * toMEL	(	int	n_bins,
		float	min_freq = 0.0f,
		float	max_freq = 0.0f,
		bool	power = false )

inline

Convert the FFT result to MEL spectrum. The triangular filterbank uses fractional (HTK style) weights, so no filter collapses to zero width, and it is computed once and cached until the parameters change.

Parameters

n_bins	number of mel bands (<= 0: size())
min_freq	lower edge in Hz (<= 0: frequency(0))
max_freq	upper edge in Hz (<= 0: frequency(size() - 1))
power	use the power spectrum \|X\|^2 instead of the magnitude \|X\|

◆ updateMelFilterbank()

bool updateMelFilterbank	(	int	n_bins,
		float	min_freq,
		float	max_freq )

inlineprotected

(Re)builds the cached sparse filterbank if any parameter changed

◆ windowedSample()

template<typename T>

T windowedSample	(	T	sample,
		int	pos )

inlineprotected

◆ write() [1/2]

virtual size_t write ( uint8_t ch )

inlineoverridevirtualinherited

Reimplemented in AudioStreamWrapper, AudioStreamWrapper, BufferedStream, BufferedStream, MemoryStream, MemoryStream, RingBufferStream, RingBufferStream, AudioStreamWrapper, BufferedStream, BufferedTaskStream, MemoryStream, RingBufferStream, and URLStream.

◆ write() [2/2]

size_t write	(	const uint8_t *	data,
		size_t	len )

inlineoverridevirtual

Provide the audio data as FFT input.

Reimplemented from AudioStream.

◆ writeIFFT()

template<typename T>

void writeIFFT	(	float *	data,
		int	len )

inlineprotected

◆ writeSilence() [1/2]

virtual void writeSilence ( size_t len )

inlinevirtualinherited

Writes len bytes of silence (=0).

◆ writeSilence() [2/2]

virtual void writeSilence ( size_t len )

inlinevirtualinherited

Writes len bytes of silence (=0).

◆ writeStrideBuffer()

bool writeStrideBuffer	(	uint8_t *	buffer,
		size_t	len )

inlineprotected

Member Data Documentation

◆ _timeout

int _timeout = 10

protectedinherited

◆ bins

int bins = 0

protected

◆ cfg

AudioFFTConfig cfg

protected

◆ current_pos

int current_pos = 0

protected

◆ has_rfft_data

bool has_rfft_data = false

protected

◆ info

AudioInfo info

protectedinherited

◆ is_notify_active

bool is_notify_active = true

protectedinherited

◆ l_magnitudes

Vector<float> l_magnitudes {0}

protected

◆ mel_bins

Vector<float> mel_bins {0}

protected

◆ mel_filters

Vector<MelFilter> mel_filters {0}

protected

◆ mel_length

int mel_length = 0

protected

◆ mel_max_freq

float mel_max_freq = -1.0f

protected

◆ mel_min_freq

float mel_min_freq = -1.0f

protected

◆ mel_n_bins

int mel_n_bins = 0

protected

◆ mel_sample_rate

int mel_sample_rate = 0

protected

◆ mel_weights

Vector<float> mel_weights {0}

protected

◆ notify_vector

Vector< AudioInfoSupport * > notify_vector

protectedinherited

◆ p_driver

FFTDriver* p_driver = nullptr

protected

◆ rfft_add

FFTInverseOverlapAdder rfft_add {0}

protected

◆ rfft_data

RingBuffer<uint8_t> rfft_data {0}

protected

◆ step_data

Vector<float> step_data {0}

protected

◆ stride_buffer

SingleBuffer<uint8_t> stride_buffer {0}

protected

◆ timestamp

unsigned long timestamp = 0l

protected

◆ timestamp_begin

unsigned long timestamp_begin = 0l

protected

◆ tmp_in

RingBuffer< uint8_t > tmp_in {0}

protectedinherited

◆ tmp_out

RingBuffer< uint8_t > tmp_out {0}

protectedinherited

◆ write_buffer_size

int write_buffer_size = 8

protectedinherited

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

src/AudioTools/FFT/AudioFFT.h

Classes

Public Member Functions

Protected Member Functions

Static Protected Member Functions

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

◆ AudioFFTBase() [1/2]

◆ AudioFFTBase() [2/2]

◆ ~AudioFFTBase()

Member Function Documentation

◆ addNotifyAudioChange() [1/2]

◆ addNotifyAudioChange() [2/2]

◆ audioInfo() [1/2]

◆ audioInfo() [2/2]

◆ audioInfoOut() [1/2]

◆ audioInfoOut() [2/2]

◆ available()

◆ availableForWrite()

◆ begin() [1/2]

◆ begin() [2/2]

◆ bytesPerSample()

◆ clearBins()

◆ clearNotifyAudioChange() [1/2]

◆ clearNotifyAudioChange() [2/2]

◆ config()

◆ defaultConfig()

◆ driver()

◆ end()

◆ fft()

◆ flush() [1/2]

◆ flush() [2/2]

◆ frequency()

◆ frequencyToBin()

◆ fromMEL()

◆ getBin()

◆ hzToMel()

◆ insertSorted()

◆ isNotifyActive() [1/2]

◆ isNotifyActive() [2/2]

◆ isPowerOfTwo()

◆ length()

◆ magnitude()

◆ magnitudeFast()

◆ magnitudes()

◆ magnitudesFast()

◆ melToHz()

◆ not_supported() [1/2]

◆ not_supported() [2/2]

◆ notifyAudioChange() [1/2]

◆ notifyAudioChange() [2/2]

◆ operator bool()

◆ operator=()

◆ phase()

◆ processSamples()

◆ processStrideBuffer()

◆ readBytes()

◆ readSilence() [1/2]

◆ readSilence() [2/2]

◆ reference()

◆ refillReadBuffer() [1/2]

◆ refillReadBuffer() [2/2]

◆ removeNotifyAudioChange() [1/2]

◆ removeNotifyAudioChange() [2/2]

◆ reset()

◆ result()

◆ resultArray()

◆ resultTime()

◆ resultTimeBegin()

◆ rfft()

◆ rfftWriteData()

◆ setAudioInfo() [1/2]

◆ setAudioInfo() [2/2]

◆ setBin() [1/2]

◆ setBin() [2/2]

◆ setNotifyActive() [1/2]

◆ setNotifyActive() [2/2]

◆ setWriteBufferSize() [1/2]

◆ setWriteBufferSize() [2/2]

◆ size()