onsetdetection.h File Reference

Onset detection functions. More...

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Typedefs

typedef _aubio_onsetdetection_t aubio_onsetdetection_t
 onsetdetection structure

Enumerations

enum  aubio_onsetdetection_type {
  aubio_onset_energy, aubio_onset_specdiff, aubio_onset_hfc, aubio_onset_complex,
  aubio_onset_phase, aubio_onset_kl, aubio_onset_mkl
}
 onsetdetection types More...

Functions

void aubio_onsetdetection_energy (aubio_onsetdetection_t *o, cvec_t *fftgrain, fvec_t *onset)
 Energy based onset detection function.
void aubio_onsetdetection_hfc (aubio_onsetdetection_t *o, cvec_t *fftgrain, fvec_t *onset)
 High Frequency Content onset detection function.
void aubio_onsetdetection_complex (aubio_onsetdetection_t *o, cvec_t *fftgrain, fvec_t *onset)
 Complex Domain Method onset detection function.
void aubio_onsetdetection_phase (aubio_onsetdetection_t *o, cvec_t *fftgrain, fvec_t *onset)
 Phase Based Method onset detection function.
void aubio_onsetdetection_specdiff (aubio_onsetdetection_t *o, cvec_t *fftgrain, fvec_t *onset)
 Spectral difference method onset detection function.
void aubio_onsetdetection_kl (aubio_onsetdetection_t *o, cvec_t *fftgrain, fvec_t *onset)
 Kullback-Liebler onset detection function.
void aubio_onsetdetection_mkl (aubio_onsetdetection_t *o, cvec_t *fftgrain, fvec_t *onset)
 Modified Kullback-Liebler onset detection function.
void aubio_onsetdetection (aubio_onsetdetection_t *o, cvec_t *fftgrain, fvec_t *onset)
 execute onset detection function on a spectral frame
aubio_onsetdetection_t * new_aubio_onsetdetection (aubio_onsetdetection_type type, uint_t size, uint_t channels)
 creation of an onset detection object
void del_aubio_onsetdetection (aubio_onsetdetection_t *o)
 deletion of an onset detection object
void aubio_onsetdetection_free (aubio_onsetdetection_t *o)
 deletion of an onset detection object (obsolete)

Detailed Description

Onset detection functions.

All of the following onset detection function take as arguments the FFT of a windowed signal (as created with aubio_pvoc). They output one smpl_t per buffer and per channel (stored in a vector of size [channels]x[1]).

These functions were first adapted from Juan Pablo Bello's code, and now include further improvements and modifications made within aubio.

Enumeration Type Documentation

enum aubio_onsetdetection_type

onsetdetection types

Enumerator:
aubio_onset_energy  energy based
aubio_onset_specdiff  spectral diff
aubio_onset_hfc  high frequency content
aubio_onset_complex  complex domain
aubio_onset_phase  phase fast
aubio_onset_kl  Kullback Liebler.
aubio_onset_mkl  modified Kullback Liebler

Function Documentation

void aubio_onsetdetection ( aubio_onsetdetection_t *  o,
cvec_t *  fftgrain,
fvec_t *  onset 
)

execute onset detection function on a spectral frame

Generic function to compute onset detection.

Parameters:
o onset detection object as returned by new_aubio_onsetdetection()
fftgrain input signal spectrum as computed by aubio_pvoc_do
onset output vector (one sample long, to send to the peak picking)

void aubio_onsetdetection_complex ( aubio_onsetdetection_t *  o,
cvec_t *  fftgrain,
fvec_t *  onset 
)

Complex Domain Method onset detection function.

Christopher Duxbury, Mike E. Davies, and Mark B. Sandler. Complex domain onset detection for musical signals. In Proceedings of the Digital Audio Effects Conference, DAFx-03, pages 90-93, London, UK, 2003.

Parameters:
o onset detection object as returned by new_aubio_onsetdetection()
fftgrain input spectral frame
onset output onset detection function

void aubio_onsetdetection_energy ( aubio_onsetdetection_t *  o,
cvec_t *  fftgrain,
fvec_t *  onset 
)

Energy based onset detection function.

This function calculates the local energy of the input spectral frame.

Parameters:
o onset detection object as returned by new_aubio_onsetdetection()
fftgrain input spectral frame
onset output onset detection function

void aubio_onsetdetection_free ( aubio_onsetdetection_t *  o  ) 

deletion of an onset detection object (obsolete)

Parameters:
o onset detection object as returned by new_aubio_onsetdetection()

void aubio_onsetdetection_hfc ( aubio_onsetdetection_t *  o,
cvec_t *  fftgrain,
fvec_t *  onset 
)

High Frequency Content onset detection function.

This method computes the High Frequency Content (HFC) of the input spectral frame. The resulting function is efficient at detecting percussive onsets.

Paul Masri. Computer modeling of Sound for Transformation and Synthesis of Musical Signal. PhD dissertation, University of Bristol, UK, 1996.

Parameters:
o onset detection object as returned by new_aubio_onsetdetection()
fftgrain input spectral frame
onset output onset detection function

void aubio_onsetdetection_kl ( aubio_onsetdetection_t *  o,
cvec_t *  fftgrain,
fvec_t *  onset 
)

Kullback-Liebler onset detection function.

Stephen Hainsworth and Malcom Macleod. Onset detection in music audio signals. In Proceedings of the International Computer Music Conference (ICMC), Singapore, 2003.

Parameters:
o onset detection object as returned by new_aubio_onsetdetection()
fftgrain input spectral frame
onset output onset detection function

void aubio_onsetdetection_mkl ( aubio_onsetdetection_t *  o,
cvec_t *  fftgrain,
fvec_t *  onset 
)

Modified Kullback-Liebler onset detection function.

Paul Brossier, ``Automatic annotation of musical audio for interactive systems'', Chapter 2, Temporal segmentation, PhD thesis, Centre for Digital music, Queen Mary University of London, London, UK, 2006.

Parameters:
o onset detection object as returned by new_aubio_onsetdetection()
fftgrain input spectral frame
onset output onset detection function

void aubio_onsetdetection_phase ( aubio_onsetdetection_t *  o,
cvec_t *  fftgrain,
fvec_t *  onset 
)

Phase Based Method onset detection function.

Juan-Pablo Bello, Mike P. Davies, and Mark B. Sandler. Phase-based note onset detection for music signals. In Proceedings of the IEEE International Conference on Acoustics Speech and Signal Processing, pages 441­444, Hong-Kong, 2003.

Parameters:
o onset detection object as returned by new_aubio_onsetdetection()
fftgrain input spectral frame
onset output onset detection function

void aubio_onsetdetection_specdiff ( aubio_onsetdetection_t *  o,
cvec_t *  fftgrain,
fvec_t *  onset 
)

Spectral difference method onset detection function.

Jonhatan Foote and Shingo Uchihashi. The beat spectrum: a new approach to rhythm analysis. In IEEE International Conference on Multimedia and Expo (ICME 2001), pages 881­884, Tokyo, Japan, August 2001.

Parameters:
o onset detection object as returned by new_aubio_onsetdetection()
fftgrain input spectral frame
onset output onset detection function

void del_aubio_onsetdetection ( aubio_onsetdetection_t *  o  ) 

deletion of an onset detection object

Parameters:
o onset detection object as returned by new_aubio_onsetdetection()

aubio_onsetdetection_t* new_aubio_onsetdetection ( aubio_onsetdetection_type  type,
uint_t  size,
uint_t  channels 
)

creation of an onset detection object

Parameters:
type onset detection mode
size length of the input spectrum frame
channels number of input channels

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