STFT Class Reference

Short-time Fourier transform. More...

#include <DFT.h>

Inheritance diagram for STFT:

List of all members.

Public Member Functions
	STFT (uint32_t winSize=1024, uint32_t hopSize=256, uint32_t padSize=0, WindowType winType=RECTANGLE, SpectralType specType=COMPLEX, uint32_t numAux=0)
bool	operator() (float input)
	Input next time-domain sample.
void	forward (const float *src)
	Perform forward transform of an array of samples.
virtual void	inverse (float *dst)
	Get inverse transform using current spectral frame.
void	resize (uint32_t winSize, uint32_t padSize)
	Set window and zero-padding size, in samples.
STFT &	inverseWindowing (bool v)
	Whether to apply a triangular window to inverse transform samples.
STFT &	rotateForward (bool v)
	Whether to rotate input samples by half.
STFT &	sizeHop (uint32_t size)
	Set hop size, in samples.
STFT &	windowType (WindowType type)
	Set window type.
float *	phases ()
	Returns array of phases if the sample data type is MAG_FREQ.
DFT &	spectrumType (SpectralType v)
	Set format of spectrum data.
DFT &	precise (bool whether)
	Set whether to use precise (but slower) for converting to polar.
float	freqRes () const
	Get frequency resolution of analysis.
float	overlap () const
	Get transform overlap factor.
bool	overlapping () const
	Whether the transform is overlapping.
uint32_t	sizeHop () const
	Get size of hop.
uint32_t	sizePad () const
	Get size of zero-padding.
uint32_t	sizeWin () const
	Get size of window.
Sync &	syncHop ()
	Hop rate synchronizer.
float	operator() ()
	Returns next sample from inverse transform.
bool	inverseOnNext ()
	Returns true if next call to inverse() will perform the inverse transform.
void	zero ()
	Zeroes internal frequency bins.
void	zeroEnds ()
	Zeroes DC and Nyquist bins.
virtual void	onResync (double r)
	Called by my Sync reference after it changes its value.
float *	aux (uint32_t num)
	Get pointer to an auxiliary buffer.
Complex< float > *	bins () const
	Get pointer to bin data.
Complex< float > &	bin (uint32_t k)
	Get reference to bin value.
const Complex< float > &	bin (uint32_t k) const
	Get read-only reference to bin value.
double	binFreq () const
	Get width of frequency bins.
uint32_t	numBins () const
	Get number of frequency bins.
uint32_t	sizeDFT () const
	Get size of forward transform.
Sync &	syncFreq ()
	Get frequency domain synchronizer.
void	numAux (uint32_t num)
	Sets number of auxilliary buffers, each of size numBins()
double	scaleSPU () const
	Returns ratio of my SPU to my Sync's SPU.
void	scaleSPU (double v)
	Scales samples/unit by factor.
double	spu () const
	Returns local samples/unit.
void	spu (double v)
	Set local samples/unit.
double	ups () const
	Returns local units/sample.
void	ups (double v)
	Set local units/sample.
const Sync *	sync () const
	Returns reference to my Sync.
void	sync (Sync &src)
	Set absolute Sync source.
void	scaleUPS (double v)
	Scales units/sample by factor.
void	nodeInsertL (Synced &node)
	Insert myself to left of node.
void	nodeInsertR (Synced &node)
	Insert myself to right of node.
void	nodeRemove ()
	Remove myself from linked list.
Public Attributes
Synced *	nodeL
	Pointer to left node.
Synced *	nodeR
	Pointer to right node.
Protected Member Functions
void	initSynced ()
	To be called from the constructor(s) of derived classes.

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Detailed Description

Short-time Fourier transform.

The short-time Fourier transform uses a sliding window during analysis to obtain better time resolution between successive spectral frames. The resolution within each individual spectral frame is still determined by the window size.

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Constructor & Destructor Documentation

STFT	(	uint32_t	winSize = 1024,
		uint32_t	hopSize = 256,
		uint32_t	padSize = 0,
		WindowType	winType = RECTANGLE,
		SpectralType	specType = COMPLEX,
		uint32_t	numAux = 0
	)

Parameters:

[in]	winSize	Number of samples to window
[in]	hopSize	Number of samples between successive windows
[in]	padSize	Number of zeros to append to window
[in]	winType	Type of forward transform window
[in]	specType	Format of spectrum data
[in]	numAux	Number of auxiliary buffers to create

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Member Function Documentation

bool inverseOnNext

(

)

[inherited]

Returns true if next call to inverse() will perform the inverse transform.

This method is used for doing inverse-only transforms. Basically, it tells you when you should set the frequency samples.

void onResync

(

double

ratioSPU

)

[virtual, inherited]

Called by my Sync reference after it changes its value.

Any instance state that depends on the sampling length should be updated here.

Reimplemented from DFTBase< float >.

float operator()

(

)

[inherited]

Returns next sample from inverse transform.

The inverse transform is performed every sizeWin() samples.

bool operator()

(

float

input

)

Input next time-domain sample.

Returns:

whether a new spectral frame is available

Reimplemented from DFT.

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

• /Users/ljp/code/gamma/trunk/Gamma/DFT.h
• /Users/ljp/code/gamma/trunk/src/DFT.cpp