AudioCmsisFFT Class Reference

AudioFFT for ARM processors that provided Cmsis DSP. More...

#include <AudioCmsisFFT.h>

Inheritance diagram for AudioCmsisFFT:

Public Member Functions
	AudioCmsisFFT ()
virtual void	addNotifyAudioChange (AudioInfoSupport &bi)
	Adds target to be notified about audio changes.
float *	array ()
	Provides the result array returned by CMSIS FFT.
virtual AudioInfo	audioInfo () override
	provides the actual input AudioInfo
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.
AudioFFTConfig &	config ()
	Provides the actual configuration.
AudioFFTConfig	defaultConfig (RxTxMode mode=TX_MODE)
	Provides the default configuration.
FFTDriver *	driver ()
FFTDriverCmsisFFT *	driverEx ()
void	end () override
	Release the allocated memory.
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.
bool	getBin (int pos, FFTBin &bin)
	gets the value of a bin
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
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.
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.
void	reset ()
	Just resets the current_pos e.g. to start a new cycle.
AudioFFTResult	result ()
template<int N>
void	resultArray (AudioFFTResult(&result)[N])
	Determines the N biggest result values.
unsigned long	resultTime ()
unsigned long	resultTimeBegin ()
	time before the fft
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	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)
	Convert the FFT result to MEL spectrum.
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)
	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="")
void	notifyAudioChange (AudioInfo info)
template<typename T >
void	processSamples (const void *data, size_t count)
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
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)

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< 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 = MAX_SINGLE_CHARS

Detailed Description

AudioFFT for ARM processors that provided Cmsis DSP.

Author

Phil Schatzmann

Copyright

GPLv3

Constructor & Destructor Documentation

AudioCmsisFFT()

AudioCmsisFFT ( )

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.

array()

float * array ( )

inline

Provides the result array returned by CMSIS FFT.

audioInfo()

virtual AudioInfo audioInfo ( )

inlineoverridevirtualinherited

provides the actual input AudioInfo

Implements AudioInfoSupport.

Reimplemented in JupyterAudioT< T >, MozziStream, TimerCallbackAudioStream, EncodedAudioStream, PureDataStream, AdapterAudioOutputToAudioStream, GeneratedSoundStream< T >, GeneratedSoundStream< int16_t >, and InputMerge< T >.

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 >.

available()

int available ( )

inlineoverridevirtualinherited

Data available for reverse fft.

Reimplemented from BaseStream.

availableForWrite()

int availableForWrite ( )

inlineoverridevirtualinherited

We try to fill the buffer at once.

Reimplemented from BaseStream.

begin() [1/2]

bool begin ( )

inlineoverridevirtualinherited

starts the processing

Reimplemented from BaseStream.

begin() [2/2]

bool begin ( AudioFFTConfig  info )

inlineinherited

starts the processing

bytesPerSample()

int bytesPerSample ( )

inlineprotectedinherited

clearBins()

void clearBins ( )

inlineinherited

clears the fft data

clearNotifyAudioChange()

virtual void clearNotifyAudioChange ( )

inlinevirtualinherited

Deletes all change notify subscriptions.

Reimplemented in RTSPClient< TcpClient, UdpSocket >.

config()

AudioFFTConfig & config ( )

inlineinherited

Provides the actual configuration.

defaultConfig()

AudioFFTConfig defaultConfig ( RxTxMode  mode = TX_MODE )

inlineinherited

Provides the default configuration.

driver()

FFTDriver * driver ( )

inlineinherited

provides access to the FFTDriver which implements the basic FFT functionality

driverEx()

FFTDriverCmsisFFT * driverEx ( )

inline

end()

void end ( )

inlineoverridevirtualinherited

Release the allocated memory.

Reimplemented from BaseStream.

fft()

template<typename T >

void fft ( )

inlineprotectedinherited

flush()

virtual void flush ( )

inlineoverridevirtualinherited

Reimplemented from Print.

Reimplemented in PureDataStream, URLStreamBufferedT< T >, URLStreamBufferedT< ICYStream >, ReformatBaseStream, AudioStreamWrapper, ResampleStream, EncodedAudioStream, URLStream, BufferedTaskStream, I2SStream, MemoryStream, RingBufferStream, GeneratedSoundStream< T >, GeneratedSoundStream< int16_t >, and BufferedStream.

frequency()

float frequency ( int  bin )

inlineinherited

Determines the frequency of the indicated bin.

frequencyToBin()

int frequencyToBin ( int  freq )

inlineinherited

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  )

inlineinherited

Convert MEL spectrum back to linear frequency spectrum.

Parameters

values	Pointer to MEL spectrum values
n_bins	Number of MEL bins

Returns

bool Success status

getBin()

bool getBin ( int  pos, FFTBin &  bin  )

inlineinherited

gets the value of a bin

insertSorted()

template<int N>

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

inlineprotectedinherited

make sure that we do not reuse already found results

isNotifyActive()

bool isNotifyActive ( )

inlineinherited

Checks if the automatic AudioInfo update is active.

isPowerOfTwo()

bool isPowerOfTwo ( uint16_t  x )

inlineprotectedinherited

length()

int length ( )

inlineinherited

The number of samples.

magnitude()

float magnitude ( int  bin )

inlineinherited

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

magnitudeFast()

float magnitudeFast ( int  bin )

inlineinherited

magnitudes()

float * magnitudes ( )

inline

magnitudesFast()

float * magnitudesFast ( )

inlineinherited

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

not_supported()

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

inlineprotectedvirtualinherited

notifyAudioChange()

void notifyAudioChange ( AudioInfo  info )

inlineprotectedinherited

operator bool()

operator bool ( )

inlineoverridevirtualinherited

Reimplemented from AudioStream.

phase()

float phase ( int  bin )

inlineinherited

calculates the phase

processSamples()

template<typename T >

void processSamples ( const void *  data, size_t  count  )

inlineprotectedinherited

readBytes()

size_t readBytes ( uint8_t *  data, size_t  len  )

inlineoverridevirtualinherited

Provides the result of a reverse FFT.

Reimplemented from AudioStream.

readSilence()

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 ( )

inlineinherited

Provides the reference pointer.

refillReadBuffer()

void refillReadBuffer ( )

inlineprotectedinherited

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

removeNotifyAudioChange()

virtual bool removeNotifyAudioChange ( AudioInfoSupport &  bi )

inlinevirtualinherited

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

Reimplemented in RTSPClient< TcpClient, UdpSocket >.

reset()

void reset ( )

inlineinherited

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

result()

AudioFFTResult result ( )

inline

resultArray()

template<int N>

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

inlineinherited

Determines the N biggest result values.

resultTime()

unsigned long resultTime ( )

inlineinherited

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 ( )

inlineinherited

time before the fft

rfft()

void rfft ( )

inlineprotectedinherited

reverse fft

rfftWriteData()

void rfftWriteData ( BaseBuffer< uint8_t > &  data )

inlineprotectedinherited

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

setAudioInfo()

void setAudioInfo ( AudioInfo  info )

inlineoverridevirtualinherited

Notify change of audio information.

Reimplemented from AudioStream.

setBin() [1/2]

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

inlineinherited

sets the value of a bin

setBin() [2/2]

bool setBin ( int  pos, FFTBin &  bin  )

inlineinherited

sets the value of a bin

setNotifyActive()

void setNotifyActive ( bool  flag )

inlineinherited

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

setWriteBufferSize()

void setWriteBufferSize ( int  size )

inlineinherited

size()

int size ( )

inlineinherited

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  )

inlineinherited

Convert the FFT result to MEL spectrum.

windowedSample()

template<typename T >

T windowedSample ( T  sample, int  pos  )

inlineprotectedinherited

write() [1/2]

size_t write ( const uint8_t *  data, size_t  len  )

inlineoverridevirtualinherited

Provide the audio data as FFT input.

Reimplemented from AudioStream.

write() [2/2]

virtual size_t write ( uint8_t  ch )

inlineoverridevirtualinherited

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

writeIFFT()

template<typename T >

void writeIFFT ( float *  data, int  len  )

inlineprotectedinherited

writeSilence()

virtual void writeSilence ( size_t  len )

inlinevirtualinherited

Writes len bytes of silence (=0).

writeStrideBuffer()

bool writeStrideBuffer ( uint8_t *  buffer, size_t  len  )

inlineprotectedinherited

Member Data Documentation

_timeout

int _timeout = 10

protectedinherited

bins

int bins = 0

protectedinherited

cfg

AudioFFTConfig cfg

protectedinherited

current_pos

int current_pos = 0

protectedinherited

has_rfft_data

bool has_rfft_data = false

protectedinherited

info

AudioInfo info

protectedinherited

is_notify_active

bool is_notify_active = true

protectedinherited

l_magnitudes

Vector<float> l_magnitudes {0}

protectedinherited

mel_bins

Vector<float> mel_bins {0}

protectedinherited

notify_vector

Vector<AudioInfoSupport*> notify_vector

protectedinherited

p_driver

FFTDriver* p_driver = nullptr

protectedinherited

rfft_add

FFTInverseOverlapAdder rfft_add {0}

protectedinherited

rfft_data

RingBuffer<uint8_t> rfft_data {0}

protectedinherited

step_data

Vector<float> step_data {0}

protectedinherited

stride_buffer

SingleBuffer<uint8_t> stride_buffer {0}

protectedinherited

timestamp

unsigned long timestamp = 0l

protectedinherited

timestamp_begin

unsigned long timestamp_begin = 0l

protectedinherited

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 = MAX_SINGLE_CHARS

protectedinherited

---

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

• src/AudioTools/FFT/AudioCmsisFFT.h