phasevoc.h File Reference

Phase vocoder object. More...

Go to the source code of this file.

Typedefs
typedef struct _aubio_pvoc_t	aubio_pvoc_t
	phasevocoder object

Functions
aubio_pvoc_t *	new_aubio_pvoc (uint_t win_s, uint_t hop_s)
	create phase vocoder object More...
void	del_aubio_pvoc (aubio_pvoc_t *pv)
	delete phase vocoder object More...
void	aubio_pvoc_do (aubio_pvoc_t *pv, const fvec_t *in, cvec_t *fftgrain)
	compute spectral frame More...
void	aubio_pvoc_rdo (aubio_pvoc_t *pv, cvec_t *fftgrain, fvec_t *out)
	compute signal from spectral frame More...
uint_t	aubio_pvoc_get_win (aubio_pvoc_t *pv)
	get window size More...
uint_t	aubio_pvoc_get_hop (aubio_pvoc_t *pv)
	get hop size More...
uint_t	aubio_pvoc_set_window (aubio_pvoc_t *pv, const char_t *window_type)
	set window type More...

Detailed Description

Phase vocoder object.

This object implements a phase vocoder. The spectral frames are computed using a HanningZ window and a swapped version of the signal to simplify the phase relationships across frames. The window sizes and overlap are specified at creation time.

Definition in file phasevoc.h.

Function Documentation

aubio_pvoc_do()

void aubio_pvoc_do	(	aubio_pvoc_t *	pv,
		const fvec_t *	in,
		cvec_t *	fftgrain
	)

compute spectral frame

This function accepts an input vector of size [hop_s]. The analysis buffer is rotated and filled with the new data. After windowing of this signal window, the Fourier transform is computed and returned in fftgrain as two vectors, magnitude and phase.

Parameters

pv	phase vocoder object as returned by new_aubio_pvoc
in	new input signal (hop_s long)
fftgrain	output spectral frame

Examples:

spectral/test-mfcc.c, spectral/test-phasevoc.c, and spectral/test-tss.c.

aubio_pvoc_get_hop()

uint_t aubio_pvoc_get_hop

(

aubio_pvoc_t *

pv

)

get hop size

Parameters

pv	phase vocoder to get the hop size from

Examples:

spectral/test-phasevoc.c.

aubio_pvoc_get_win()

uint_t aubio_pvoc_get_win

(

aubio_pvoc_t *

pv

)

get window size

Parameters

pv	phase vocoder to get the window size from

Examples:

spectral/test-phasevoc.c.

aubio_pvoc_rdo()

void aubio_pvoc_rdo	(	aubio_pvoc_t *	pv,
		cvec_t *	fftgrain,
		fvec_t *	out
	)

compute signal from spectral frame

This function takes an input spectral frame fftgrain of size [buf_s] and computes its inverse Fourier transform. Overlap-add synthesis is then computed using the previously synthetised frames, and the output stored in out.

Parameters

pv	phase vocoder object as returned by new_aubio_pvoc
fftgrain	input spectral frame
out	output signal (hop_s long)

Examples:

spectral/test-phasevoc.c, and spectral/test-tss.c.

aubio_pvoc_set_window()

uint_t aubio_pvoc_set_window	(	aubio_pvoc_t *	pv,
		const char_t *	window_type
	)

set window type

Parameters

pv	phase vocoder to set the window type
window_type	a string representing a window

Returns

0 if successful, non-zero otherwise

Examples:

spectral/test-phasevoc.c.

del_aubio_pvoc()

void del_aubio_pvoc

(

aubio_pvoc_t *

pv

)

delete phase vocoder object

Parameters

pv	phase vocoder object as returned by new_aubio_pvoc

Examples:

spectral/test-mfcc.c, spectral/test-phasevoc.c, and spectral/test-tss.c.

new_aubio_pvoc()

aubio_pvoc_t* new_aubio_pvoc	(	uint_t	win_s,
		uint_t	hop_s
	)

create phase vocoder object

Parameters

win_s	size of analysis buffer (and length the FFT transform)
hop_s	step size between two consecutive analysis

Examples:

spectral/test-mfcc.c, spectral/test-phasevoc.c, and spectral/test-tss.c.