fft.h File Reference

Fast Fourier Transform. More...

Go to the source code of this file.

Typedefs
typedef struct _aubio_fft_t	aubio_fft_t
	FFT object. More...

Functions
aubio_fft_t *	new_aubio_fft (uint_t size)
	create new FFT computation object More...
void	del_aubio_fft (aubio_fft_t *s)
	delete FFT object More...
void	aubio_fft_do (aubio_fft_t *s, const fvec_t *input, cvec_t *spectrum)
	compute forward FFT More...
void	aubio_fft_rdo (aubio_fft_t *s, const cvec_t *spectrum, fvec_t *output)
	compute backward (inverse) FFT More...
void	aubio_fft_do_complex (aubio_fft_t *s, const fvec_t *input, fvec_t *compspec)
	compute forward FFT More...
void	aubio_fft_rdo_complex (aubio_fft_t *s, const fvec_t *compspec, fvec_t *output)
	compute backward (inverse) FFT from real/imag More...
void	aubio_fft_get_spectrum (const fvec_t *compspec, cvec_t *spectrum)
	convert real/imag spectrum to norm/phas spectrum More...
void	aubio_fft_get_realimag (const cvec_t *spectrum, fvec_t *compspec)
	convert real/imag spectrum to norm/phas spectrum More...
void	aubio_fft_get_phas (const fvec_t *compspec, cvec_t *spectrum)
	compute phas spectrum from real/imag parts More...
void	aubio_fft_get_imag (const cvec_t *spectrum, fvec_t *compspec)
	compute imaginary part from the norm/phas cvec More...
void	aubio_fft_get_norm (const fvec_t *compspec, cvec_t *spectrum)
	compute norm component from real/imag parts More...
void	aubio_fft_get_real (const cvec_t *spectrum, fvec_t *compspec)
	compute real part from norm/phas components More...

Detailed Description

Fast Fourier Transform.

Depending on how aubio was compiled, FFT are computed using one of:

• Ooura
• FFTW3
• vDSP

Definition in file fft.h.

Typedef Documentation

aubio_fft_t

typedef struct _aubio_fft_t aubio_fft_t

FFT object.

This object computes forward and backward FFTs.

Definition at line 46 of file fft.h.

Function Documentation

aubio_fft_do()

void aubio_fft_do	(	aubio_fft_t *	s,
		const fvec_t *	input,
		cvec_t *	spectrum
	)

compute forward FFT

Parameters

s	fft object as returned by new_aubio_fft
input	input signal
spectrum	output spectrum

Examples:

spectral/test-fft.c.

aubio_fft_do_complex()

void aubio_fft_do_complex	(	aubio_fft_t *	s,
		const fvec_t *	input,
		fvec_t *	compspec
	)

compute forward FFT

Parameters

s	fft object as returned by new_aubio_fft
input	real input signal
compspec	complex output fft real/imag

aubio_fft_get_imag()

void aubio_fft_get_imag	(	const cvec_t *	spectrum,
		fvec_t *	compspec
	)

compute imaginary part from the norm/phas cvec

Parameters

spectrum	norm/phas input array
compspec	real/imag output fft array

aubio_fft_get_norm()

void aubio_fft_get_norm	(	const fvec_t *	compspec,
		cvec_t *	spectrum
	)

compute norm component from real/imag parts

Parameters

compspec	real/imag input fft array
spectrum	cvec norm/phas output array

aubio_fft_get_phas()

void aubio_fft_get_phas	(	const fvec_t *	compspec,
		cvec_t *	spectrum
	)

compute phas spectrum from real/imag parts

Parameters

compspec	real/imag input fft array
spectrum	cvec norm/phas output array

aubio_fft_get_real()

void aubio_fft_get_real	(	const cvec_t *	spectrum,
		fvec_t *	compspec
	)

compute real part from norm/phas components

Parameters

spectrum	norm/phas input array
compspec	real/imag output fft array

aubio_fft_get_realimag()

void aubio_fft_get_realimag	(	const cvec_t *	spectrum,
		fvec_t *	compspec
	)

convert real/imag spectrum to norm/phas spectrum

Parameters

compspec	real/imag input fft array
spectrum	cvec norm/phas output array

aubio_fft_get_spectrum()

void aubio_fft_get_spectrum	(	const fvec_t *	compspec,
		cvec_t *	spectrum
	)

convert real/imag spectrum to norm/phas spectrum

Parameters

compspec	real/imag input fft array
spectrum	cvec norm/phas output array

aubio_fft_rdo()

void aubio_fft_rdo	(	aubio_fft_t *	s,
		const cvec_t *	spectrum,
		fvec_t *	output
	)

compute backward (inverse) FFT

Parameters

s	fft object as returned by new_aubio_fft
spectrum	input spectrum
output	output signal

Examples:

spectral/test-fft.c.

aubio_fft_rdo_complex()

void aubio_fft_rdo_complex	(	aubio_fft_t *	s,
		const fvec_t *	compspec,
		fvec_t *	output
	)

compute backward (inverse) FFT from real/imag

Parameters

s	fft object as returned by new_aubio_fft
compspec	real/imag input fft array
output	real output array

del_aubio_fft()

void del_aubio_fft

(

aubio_fft_t *

s

)

delete FFT object

Parameters

s	fft object as returned by new_aubio_fft

Examples:

spectral/test-fft.c.

new_aubio_fft()

aubio_fft_t* new_aubio_fft

(

uint_t

size

)

create new FFT computation object

Parameters

size	length of the FFT

Examples:

spectral/test-fft.c.