AudioRealFFT Class Reference

AudioFFT using RealFFT. More...

#include <AudioRealFFT.h>

Inheritance diagram for AudioRealFFT:

Public Member Functions
virtual AudioInfo	audioInfo () override
int	availableForWrite () override
	We try to fill the buffer at once.
virtual bool	begin ()
bool	begin (AudioFFTConfig info)
	starts the processing
virtual bool	begin (AudioInfo info)
AudioFFTConfig &	config ()
	Provides the actual configuration.
AudioFFTConfig	defaultConfig ()
	Provides the default configuration.
FFTDriver *	driver ()
	provides access to the FFTDriver which implements the basic FFT functionality
FFTDriverRealFFT *	driverEx ()
void	end () override
	Release the allocated memory.
virtual void	flush () override
float	frequency (int bin)
	Determines the frequency of the indicated bin.
float *	ifft (float *real, float *complex)
	Inverse fft - convert fft result back to time domain (samples)
float *	imgArray ()
	Provides the complex array returned by the FFT
virtual bool	isDeletable ()
	If true we need to release the related memory in the destructor.
int	length ()
	The number of samples.
float	magnitude (int bin)
	Calculates the magnitude of the fft result to determine the max value (bin is 0 to size())
float	magnitudeFast (int bin)
float *	magnitudes ()
	Provides the magnitudes as array of size size(). Please note that this method is allocating additinal memory!
float *	magnitudesFast ()
	Provides the magnitudes w/o calling the square root function as array of size size(). Please note that this method is allocating additinal memory!
	operator bool ()
float *	realArray ()
	Provides the real array returned by the FFT.
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 ()
	time after the fft: time when the last result was provided - you can poll this to check if we have a new result
unsigned long	resultTimeBegin ()
	time before the fft
void	setAudioInfo (AudioInfo info) override
	Notify change of audio information.
virtual void	setNotifyAudioChange (AudioInfoSupport &bi) override
int	size ()
	The number of bins used by the FFT which are relevant for the result.
virtual bool	validate (AudioInfo &info)
size_t	write (const uint8_t *data, size_t len) override
	Provide the audio data as FFT input.
virtual size_t	write (uint8_t ch) override
virtual void	writeSilence (size_t len)

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)
template<typename T >
void	processSamples (const void *data, size_t samples)
template<typename T >
T	windowedSample (T sample)
void	writeStrideBuffer (uint8_t *buffer, size_t len)

Protected Attributes
int	bins = 0
AudioFFTConfig	cfg
int	current_pos = 0
bool	is_active = false
FFTDriver *	p_driver =nullptr
float *	p_magnitudes = nullptr
AudioInfoSupport *	p_notify = nullptr
RingBuffer< uint8_t >	stride_buffer {0}
unsigned long	timestamp =0l
unsigned long	timestamp_begin =0l
SingleBuffer< uint8_t >	tmp {MAX_SINGLE_CHARS}
int	tmpPos = 0

Detailed Description

AudioFFT using RealFFT.

Author

Phil Schatzmann

Copyright

GPLv3

Member Function Documentation

writeSilence()

virtual void writeSilence ( size_t  len )

inlinevirtualinherited

Writes n 0 values (= silence)

Parameters

len

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

• src/AudioLibs/AudioRealFFT.h