timestretch.h File Reference

time stretching object More...

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Typedefs
typedef struct _aubio_timestretch_t	aubio_timestretch_t
	time stretching object

Functions
void	aubio_timestretch_do (aubio_timestretch_t *o, fvec_t *out, uint_t *read)
	execute time stretching on an input signal frame
void	del_aubio_timestretch (aubio_timestretch_t *o)
	deletion of the time stretching object
aubio_timestretch_t *	new_aubio_timestretch (const char_t *method, smpl_t stretch, uint_t hop_size, uint_t samplerate)
	creation of the time stretching object
sint_t	aubio_timestretch_push (aubio_timestretch_t *o, fvec_t *in, uint_t length)
	push length samples from in to time stretching object
sint_t	aubio_timestretch_get_available (aubio_timestretch_t *o)
	get number of currently available samples from time stretching object
uint_t	aubio_timestretch_get_latency (aubio_timestretch_t *o)
	get the latency of the time stretching object, in samples
uint_t	aubio_timestretch_get_samplerate (aubio_timestretch_t *o)
	get the samplerate of the time stretching object
uint_t	aubio_timestretch_set_stretch (aubio_timestretch_t *o, smpl_t stretch)
	set the stretching ratio of the time stretching object
smpl_t	aubio_timestretch_get_stretch (aubio_timestretch_t *o)
	get the transposition of the time stretching object, in semitones
uint_t	aubio_timestretch_set_pitchscale (aubio_timestretch_t *o, smpl_t pitchscale)
	set the pitch scale of the time stretching object
smpl_t	aubio_timestretch_get_pitchscale (aubio_timestretch_t *o)
	get the pitchscale of the time stretching object
uint_t	aubio_timestretch_set_transpose (aubio_timestretch_t *o, smpl_t transpose)
	set the transposition of the time stretching object, in semitones
smpl_t	aubio_timestretch_get_transpose (aubio_timestretch_t *o)
	get the transposition of the time stretching object, in semitones
uint_t	aubio_timestretch_reset (aubio_timestretch_t *o)
	reset the time stretching object

Detailed Description

time stretching object

aubio_timestretch_t can be used to open a source file, read samples from it, time-stretch them, and write out the modified samples.

The time-stretching factor can be changed at any time using aubio_timestretch_set_stretch().

A transposition can also be applied and changed at any time with aubio_timestretch_set_transpose().

Definition in file timestretch.h.

Typedef Documentation

aubio_timestretch_t

typedef struct _aubio_timestretch_t aubio_timestretch_t

time stretching object

Examples

effects/test-timestretch.c.

Definition at line 46 of file timestretch.h.

Function Documentation

aubio_timestretch_do()

void aubio_timestretch_do	(	aubio_timestretch_t *	o,
		fvec_t *	out,
		uint_t *	read )

execute time stretching on an input signal frame

Parameters

o	time stretching object as returned by new_aubio_timestretch()
out	timestretched output of size [hop_size]
read	number of frames actually wrote out

Examples

effects/test-timestretch.c.

aubio_timestretch_get_available()

sint_t aubio_timestretch_get_available

(

aubio_timestretch_t *

o

)

get number of currently available samples from time stretching object

Parameters

o	time stretching object as returned by new_aubio_timestretch()

Returns

number of currently available samples

Examples

effects/test-timestretch.c.

aubio_timestretch_get_latency()

uint_t aubio_timestretch_get_latency

(

aubio_timestretch_t *

o

)

get the latency of the time stretching object, in samples

Parameters

o	time stretching object as returned by new_aubio_timestretch()

Returns

latency of the time stretching object in samples

Examples

effects/test-timestretch.c.

aubio_timestretch_get_pitchscale()

smpl_t aubio_timestretch_get_pitchscale

(

aubio_timestretch_t *

o

)

get the pitchscale of the time stretching object

Parameters

o	time stretching object as returned by new_aubio_timestretch()

Returns

pitchscale of the time stretching object

Examples

effects/test-timestretch.c.

aubio_timestretch_get_samplerate()

uint_t aubio_timestretch_get_samplerate

(

aubio_timestretch_t *

o

)

get the samplerate of the time stretching object

Call after new_aubio_timestretch() was called with 0 to match the original samplerate of the input file.

Parameters

o	time stretching object as returned by new_aubio_timestretch()

Returns

samplerate of the time stretching object

Examples

effects/test-timestretch.c.

aubio_timestretch_get_stretch()

smpl_t aubio_timestretch_get_stretch

(

aubio_timestretch_t *

o

)

get the transposition of the time stretching object, in semitones

Parameters

o	time stretching object as returned by new_aubio_timestretch()

Returns

time stretching ratio of the time stretching object, in the range [0.025; 10.]

Examples

effects/test-timestretch.c.

aubio_timestretch_get_transpose()

smpl_t aubio_timestretch_get_transpose

(

aubio_timestretch_t *

o

)

get the transposition of the time stretching object, in semitones

Parameters

o	time stretching object as returned by new_aubio_timestretch()

Returns

transposition of the time stretching object, in semitones

Examples

effects/test-timestretch.c.

aubio_timestretch_push()

sint_t aubio_timestretch_push	(	aubio_timestretch_t *	o,
		fvec_t *	in,
		uint_t	length )

push length samples from in to time stretching object

Parameters

o	time stretching object as returned by new_aubio_timestretch()
in	input vector of new samples to push to time stretching object
length	number of new samples to push from input vector

Returns

number of currently available samples

Examples

effects/test-timestretch.c.

aubio_timestretch_reset()

uint_t aubio_timestretch_reset

(

aubio_timestretch_t *

o

)

reset the time stretching object

Parameters

o	time stretching object as returned by new_aubio_timestretch()

Returns

0 on success, non-zero otherwise

Examples

effects/test-timestretch.c.

aubio_timestretch_set_pitchscale()

uint_t aubio_timestretch_set_pitchscale	(	aubio_timestretch_t *	o,
		smpl_t	pitchscale )

set the pitch scale of the time stretching object

Parameters

o	time stretching object as returned by new_aubio_timestretch()
pitchscale	new pitch scale of the time stretching object

pitchscale is a frequency ratio. It should be in the range [0.25, 4].

Returns

0 if successfull, non-zero otherwise

Examples

effects/test-timestretch.c.

aubio_timestretch_set_stretch()

uint_t aubio_timestretch_set_stretch	(	aubio_timestretch_t *	o,
		smpl_t	stretch )

set the stretching ratio of the time stretching object

Parameters

o	time stretching object as returned by new_aubio_timestretch()
stretch	new time stretching ratio of the time stretching object (should be in the range [0.025; 10.])

Returns

0 if successfull, non-zero otherwise

Examples

effects/test-timestretch.c.

aubio_timestretch_set_transpose()

uint_t aubio_timestretch_set_transpose	(	aubio_timestretch_t *	o,
		smpl_t	transpose )

set the transposition of the time stretching object, in semitones

Parameters

o	time stretching object as returned by new_aubio_timestretch()
transpose	new pitch transposition of the time stretching object, expressed in semitones (should be in the range [-24;+24])

Returns

0 if successfull, non-zero otherwise

Examples

effects/test-timestretch.c.

del_aubio_timestretch()

void del_aubio_timestretch

(

aubio_timestretch_t *

o

)

deletion of the time stretching object

Parameters

o	time stretching object as returned by new_aubio_timestretch()

Examples

effects/test-timestretch.c.

new_aubio_timestretch()

aubio_timestretch_t * new_aubio_timestretch	(	const char_t *	method,
		smpl_t	stretch,
		uint_t	hop_size,
		uint_t	samplerate )

creation of the time stretching object

Parameters

method	time stretching algorithm ("default")
stretch	initial time stretching factor
hop_size	block size at which the frames should be produced
samplerate	sampling rate of the signal

Returns

newly created aubio_timestretch_t

Examples

effects/test-timestretch.c.