onset/onset.h File Reference

Onset detection object. More...

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Typedefs
typedef struct _aubio_onset_t	aubio_onset_t
	onset detection object
Functions
aubio_onset_t *	new_aubio_onset (char_t *method, uint_t buf_size, uint_t hop_size, uint_t samplerate)
	create onset detection object
void	aubio_onset_do (aubio_onset_t *o, fvec_t *input, fvec_t *onset)
	execute onset detection
uint_t	aubio_onset_get_last (aubio_onset_t *o)
	get the time of the latest onset detected, in samples
smpl_t	aubio_onset_get_last_s (aubio_onset_t *o)
	get the time of the latest onset detected, in seconds
smpl_t	aubio_onset_get_last_ms (aubio_onset_t *o)
	get the time of the latest onset detected, in milliseconds
uint_t	aubio_onset_set_silence (aubio_onset_t *o, smpl_t silence)
	set onset detection silence threshold
smpl_t	aubio_onset_get_silence (aubio_onset_t *o)
	get onset detection silence threshold
smpl_t	aubio_onset_get_descriptor (aubio_onset_t *o)
	get onset detection function
smpl_t	aubio_onset_get_thresholded_descriptor (aubio_onset_t *o)
	get thresholded onset detection function
uint_t	aubio_onset_set_threshold (aubio_onset_t *o, smpl_t threshold)
	set onset detection peak picking threshold
uint_t	aubio_onset_set_minioi (aubio_onset_t *o, uint_t minioi)
	set minimum inter onset interval in samples
uint_t	aubio_onset_set_minioi_s (aubio_onset_t *o, smpl_t minioi)
	set minimum inter onset interval in seconds
uint_t	aubio_onset_set_minioi_ms (aubio_onset_t *o, smpl_t minioi)
	set minimum inter onset interval in milliseconds
uint_t	aubio_onset_set_delay (aubio_onset_t *o, uint_t delay)
	set delay in samples
uint_t	aubio_onset_set_delay_s (aubio_onset_t *o, smpl_t delay)
	set delay in seconds
uint_t	aubio_onset_set_delay_ms (aubio_onset_t *o, smpl_t delay)
	set delay in milliseconds
uint_t	aubio_onset_get_minioi (aubio_onset_t *o)
	get minimum inter onset interval in samples
smpl_t	aubio_onset_get_minioi_s (aubio_onset_t *o)
	get minimum inter onset interval in seconds
smpl_t	aubio_onset_get_minioi_ms (aubio_onset_t *o)
	get minimum inter onset interval in milliseconds
uint_t	aubio_onset_get_delay (aubio_onset_t *o)
	get delay in samples
smpl_t	aubio_onset_get_delay_s (aubio_onset_t *o)
	get delay in seconds
smpl_t	aubio_onset_get_delay_ms (aubio_onset_t *o)
	get delay in milliseconds
smpl_t	aubio_onset_get_threshold (aubio_onset_t *o)
	get onset peak picking threshold
void	del_aubio_onset (aubio_onset_t *o)
	delete onset detection object

---

Detailed Description

Onset detection object.

The following routines compute the onset detection function and detect peaks in these functions. When onsets are found above a given silence threshold, and after a minimum inter-onset interval, the output vector returned by aubio_onset_do() is filled with `1`. Otherwise, the output vector remains `0`.

The peak-picking threshold, the silence threshold, and the minimum inter-onset interval can be adjusted during the execution of the aubio_onset_do routine using the corresponding functions.

Definition in file onset.h.

---

Function Documentation

void aubio_onset_do	(	aubio_onset_t *	o,
		fvec_t *	input,
		fvec_t *	onset
	)

execute onset detection

Parameters:

	o	onset detection object as returned by new_aubio_onset()
	input	new audio vector of length hop_size
	onset	output vector of length 1, containing 0 if no onset was found, and a value equal or greater than 1 otherwise

When no onset was detected, the first element of the output vector `onset` is set to 0.

When an onset is found, the first element of the output vector `onset` is set to `offset = 1 + a` where `a` is a number in the range`[0, 1]`.

The final onset detection time, in samples, can be obtained with aubio_onset_get_last(). It can also be derived from `offset` as follows:

    t = total_frames + offset * hop_size - delay

where `total_frames` is the total number of frames processed so far, and `delay` is the current delay of the onset object, as returned by aubio_onset_get_delay().

Examples:

examples/aubionotes.c, examples/aubioonset.c, and onset/test-onset.c.

uint_t aubio_onset_get_delay

(

aubio_onset_t *

o

)

get delay in samples

Parameters:

o

onset detection object as returned by new_aubio_onset()

Returns:

constant system delay to take back from detection time (in samples)

smpl_t aubio_onset_get_delay_ms

(

aubio_onset_t *

o

)

get delay in milliseconds

Parameters:

o

onset detection object as returned by new_aubio_onset()

Returns:

constant system delay to take back from detection time (in milliseconds)

smpl_t aubio_onset_get_delay_s

(

aubio_onset_t *

o

)

get delay in seconds

Parameters:

o

onset detection object as returned by new_aubio_onset()

Returns:

constant system delay to take back from detection time (in seconds)

smpl_t aubio_onset_get_descriptor

(

aubio_onset_t *

o

)

get onset detection function

Parameters:

o

onset detection object as returned by new_aubio_onset()

Returns:

the current value of the descriptor

uint_t aubio_onset_get_last

(

aubio_onset_t *

o

)

get the time of the latest onset detected, in samples

Parameters:

o

onset detection object as returned by new_aubio_onset()

Returns:

onset detection timestamps (in samples)

Examples:

onset/test-onset.c.

smpl_t aubio_onset_get_last_ms

(

aubio_onset_t *

o

)

get the time of the latest onset detected, in milliseconds

Parameters:

o

onset detection object as returned by new_aubio_onset()

Returns:

onset detection timestamps (in milliseconds)

Examples:

onset/test-onset.c.

smpl_t aubio_onset_get_last_s

(

aubio_onset_t *

o

)

get the time of the latest onset detected, in seconds

Parameters:

o

onset detection object as returned by new_aubio_onset()

Returns:

onset detection timestamps (in seconds)

Examples:

examples/aubioonset.c, and onset/test-onset.c.

uint_t aubio_onset_get_minioi

(

aubio_onset_t *

o

)

get minimum inter onset interval in samples

Parameters:

o

onset detection object as returned by new_aubio_onset()

Returns:

minimum interval between two consecutive onsets (in samples)

smpl_t aubio_onset_get_minioi_ms

(

aubio_onset_t *

o

)

get minimum inter onset interval in milliseconds

Parameters:

o

onset detection object as returned by new_aubio_onset()

Returns:

minimum interval between two consecutive onsets (in milliseconds)

smpl_t aubio_onset_get_minioi_s

(

aubio_onset_t *

o

)

get minimum inter onset interval in seconds

Parameters:

o

onset detection object as returned by new_aubio_onset()

Returns:

minimum interval between two consecutive onsets (in seconds)

smpl_t aubio_onset_get_silence

(

aubio_onset_t *

o

)

get onset detection silence threshold

Parameters:

o

onset detection object as returned by new_aubio_onset()

Returns:

current silence threshold

smpl_t aubio_onset_get_threshold

(

aubio_onset_t *

o

)

get onset peak picking threshold

Parameters:

o

onset detection object as returned by new_aubio_onset()

Returns:

current onset detection threshold

smpl_t aubio_onset_get_thresholded_descriptor

(

aubio_onset_t *

o

)

get thresholded onset detection function

Parameters:

o

onset detection object as returned by new_aubio_onset()

Returns:

the value of the thresholded descriptor

uint_t aubio_onset_set_delay	(	aubio_onset_t *	o,
		uint_t	delay
	)

set delay in samples

Parameters:

	o	onset detection object as returned by new_aubio_onset()
	delay	constant system delay to take back from detection time (in samples)

uint_t aubio_onset_set_delay_ms	(	aubio_onset_t *	o,
		smpl_t	delay
	)

set delay in milliseconds

Parameters:

	o	onset detection object as returned by new_aubio_onset()
	delay	constant system delay to take back from detection time (in milliseconds)

uint_t aubio_onset_set_delay_s	(	aubio_onset_t *	o,
		smpl_t	delay
	)

set delay in seconds

Parameters:

	o	onset detection object as returned by new_aubio_onset()
	delay	constant system delay to take back from detection time (in seconds)

uint_t aubio_onset_set_minioi	(	aubio_onset_t *	o,
		uint_t	minioi
	)

set minimum inter onset interval in samples

Parameters:

	o	onset detection object as returned by new_aubio_onset()
	minioi	minimum interval between two consecutive onsets (in samples)

uint_t aubio_onset_set_minioi_ms	(	aubio_onset_t *	o,
		smpl_t	minioi
	)

set minimum inter onset interval in milliseconds

Parameters:

	o	onset detection object as returned by new_aubio_onset()
	minioi	minimum interval between two consecutive onsets (in milliseconds)

uint_t aubio_onset_set_minioi_s	(	aubio_onset_t *	o,
		smpl_t	minioi
	)

set minimum inter onset interval in seconds

Parameters:

	o	onset detection object as returned by new_aubio_onset()
	minioi	minimum interval between two consecutive onsets (in seconds)

uint_t aubio_onset_set_silence	(	aubio_onset_t *	o,
		smpl_t	silence
	)

set onset detection silence threshold

Parameters:

	o	onset detection object as returned by new_aubio_onset()
	silence	new silence detection threshold

Examples:

examples/aubioonset.c.

uint_t aubio_onset_set_threshold	(	aubio_onset_t *	o,
		smpl_t	threshold
	)

set onset detection peak picking threshold

Parameters:

	o	onset detection object as returned by new_aubio_onset()
	threshold	new peak-picking threshold

Examples:

examples/aubionotes.c, and examples/aubioonset.c.

void del_aubio_onset

(

aubio_onset_t *

o

)

delete onset detection object

Parameters:

o

onset detection object to delete

Examples:

examples/aubioonset.c, and onset/test-onset.c.

aubio_onset_t* new_aubio_onset	(	char_t *	method,
		uint_t	buf_size,
		uint_t	hop_size,
		uint_t	samplerate
	)

create onset detection object

Parameters:

	method	onset detection type as specified in specdesc.h
	buf_size	buffer size for phase vocoder
	hop_size	hop size for phase vocoder
	samplerate	sampling rate of the input signal

Returns:

newly created aubio_onset_t

Examples:

examples/aubionotes.c, examples/aubioonset.c, and onset/test-onset.c.