FastFourierTransform Class Reference

This class performs direct and inverse Fast Fourier Transform. More...

Public Member Functions
	FastFourierTransform ()
	Default constructor. More...
	FastFourierTransform (size_t aSize)
	Construct and initialize the instance. More...
void	fft (FloatArray input, ComplexFloatArray output)
	Perform the direct FFT. More...
size_t	getSize ()
	Get the size of the FFT. More...
void	ifft (ComplexFloatArray input, FloatArray output)
	Perform the inverse FFT. More...
void	init (size_t aSize)
	Initialize the instance. More...
	~FastFourierTransform ()

Static Public Member Functions
static FastFourierTransform *	create (size_t blocksize)
static void	destroy (FastFourierTransform *obj)

Detailed Description

This class performs direct and inverse Fast Fourier Transform.

Definition at line 14 of file FastFourierTransform.h.

Constructor & Destructor Documentation

FastFourierTransform() [1/2]

FastFourierTransform::FastFourierTransform

(

)

Default constructor.

Does not initialize the instance.

Remarks

You need to call init(size_t size) before calling any other method

Definition at line 42 of file FastFourierTransform.cpp.

Referenced by create().

FastFourierTransform() [2/2]

FastFourierTransform::FastFourierTransform

(

size_t

aSize

)

Construct and initialize the instance.

Parameters

[in]

aSize

The size of the FFT

Remarks

Only sizes of 32, 64, 128, 256, 512, 1024, 2048, 4096 are supported, due to limitations of the CMSIS library.

Note

When built for ARM Cortex-M processor series, this method uses the optimized CMSIS library

Definition at line 44 of file FastFourierTransform.cpp.

References init().

~FastFourierTransform()

FastFourierTransform::~FastFourierTransform

(

)

Definition at line 48 of file FastFourierTransform.cpp.

References ComplexFloatArray::destroy().

Member Function Documentation

create()

FastFourierTransform * FastFourierTransform::create ( size_t  blocksize )

static

Definition at line 87 of file FastFourierTransform.cpp.

References FastFourierTransform().

destroy()

void FastFourierTransform::destroy ( FastFourierTransform *  obj )

static

Definition at line 91 of file FastFourierTransform.cpp.

fft()

void FastFourierTransform::fft	(	FloatArray	input,
		ComplexFloatArray	output
	)

Perform the direct FFT.

Parameters

[in]	input	The real-valued input array
[out]	output	The complex-valued output array

Remarks

Calling this method will mess up the content of the input array.

Note

When built for ARM Cortex-M processor series, this method uses the optimized CMSIS library

Definition at line 61 of file FastFourierTransform.cpp.

References ASSERT, SimpleArray< T >::getData(), getSize(), SimpleArray< T >::getSize(), ComplexFloatArray::im(), and ComplexFloatArray::re().

Referenced by FourierPitchDetector::process().

getSize()

size_t FastFourierTransform::getSize

(

)

Get the size of the FFT.

Returns

The size of the FFT

Definition at line 81 of file FastFourierTransform.cpp.

References SimpleArray< T >::getSize().

Referenced by fft(), FourierPitchDetector::getSize(), ifft(), and FourierPitchDetector::process().

ifft()

void FastFourierTransform::ifft	(	ComplexFloatArray	input,
		FloatArray	output
	)

Perform the inverse FFT.

The output is rescaled by 1/fftSize.

Parameters

[in]	input	The complex-valued input array
[out]	output	The real-valued output array

Remarks

Calling this method will mess up the content of the input array.

Note

When built for ARM Cortex-M processor series, this method uses the optimized CMSIS library

Definition at line 71 of file FastFourierTransform.cpp.

References ASSERT, SimpleArray< T >::getData(), getSize(), SimpleArray< T >::getSize(), and ComplexFloatArray::re().

init()

void FastFourierTransform::init

(

size_t

aSize

)

Initialize the instance.

Parameters

aSize

The size of the FFT

Note

When built for ARM Cortex-M processor series, this method uses the optimized CMSIS library

Definition at line 54 of file FastFourierTransform.cpp.

References ASSERT, and ComplexFloatArray::create().

Referenced by FastFourierTransform(), and FourierPitchDetector::init().

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

• FastFourierTransform.h
• FastFourierTransform.cpp