aubio  0.4.9
Typedefs | Functions
pitch.h File Reference

Go to the source code of this file.

Typedefs

typedef struct _aubio_pitch_t aubio_pitch_t
 pitch detection object
 

Functions

void aubio_pitch_do (aubio_pitch_t *o, const fvec_t *in, fvec_t *out)
 execute pitch detection on an input signal frame More...
 
uint_t aubio_pitch_set_tolerance (aubio_pitch_t *o, smpl_t tol)
 change yin or yinfft tolerance threshold More...
 
smpl_t aubio_pitch_get_tolerance (aubio_pitch_t *o)
 get yin or yinfft tolerance threshold More...
 
void del_aubio_pitch (aubio_pitch_t *o)
 deletion of the pitch detection object More...
 
aubio_pitch_tnew_aubio_pitch (const char_t *method, uint_t buf_size, uint_t hop_size, uint_t samplerate)
 creation of the pitch detection object More...
 
uint_t aubio_pitch_set_unit (aubio_pitch_t *o, const char_t *mode)
 set the output unit of the pitch detection object More...
 
uint_t aubio_pitch_set_silence (aubio_pitch_t *o, smpl_t silence)
 set the silence threshold of the pitch detection object More...
 
smpl_t aubio_pitch_get_silence (aubio_pitch_t *o)
 set the silence threshold of the pitch detection object More...
 
smpl_t aubio_pitch_get_confidence (aubio_pitch_t *o)
 get the current confidence More...
 

Detailed Description

Pitch detection object

This file creates the objects required for the computation of the selected pitch detection algorithm and output the results, in midi note or Hz.

Pitch detection methods

A list of the pitch detection methods currently available follows.

default : use the default method

Currently, the default method is set to yinfft .

schmitt : Schmitt trigger

This pitch extraction method implements a Schmitt trigger to estimate the period of a signal.

This file was derived from the tuneit project, written by Mario Lang to detect the fundamental frequency of a sound.

See http://delysid.org/tuneit.html

fcomb : a fast harmonic comb filter

This pitch extraction method implements a fast harmonic comb filter to determine the fundamental frequency of a harmonic sound.

This file was derived from the tuneit project, written by Mario Lang to detect the fundamental frequency of a sound.

See http://delysid.org/tuneit.html

mcomb : multiple-comb filter

This fundamental frequency estimation algorithm implements spectral flattening, multi-comb filtering and peak histogramming.

This method was designed by Juan P. Bello and described in:

Juan-Pablo Bello. `‘Towards the Automated Analysis of Simple Polyphonic Music’'. PhD thesis, Centre for Digital Music, Queen Mary University of London, London, UK, 2003.

yin : YIN algorithm

This algorithm was developed by A. de Cheveigne and H. Kawahara and published in:

De Cheveigné, A., Kawahara, H. (2002) "YIN, a fundamental frequency estimator for speech and music", J. Acoust. Soc. Am. 111, 1917-1930.

see http://recherche.ircam.fr/equipes/pcm/pub/people/cheveign.html

yinfast : Yinfast algorithm

This algorithm is equivalent to the YIN algorithm, but computed in the spectral domain for efficiency. See also python/demos/demo_yin_compare.py.

yinfft : Yinfft algorithm

This algorithm was derived from the YIN algorithm. In this implementation, a Fourier transform is used to compute a tapered square difference function, which allows spectral weighting. Because the difference function is tapered, the selection of the period is simplified.

Paul Brossier, Automatic annotation of musical audio for interactive systems, Chapter 3, Pitch Analysis, PhD thesis, Centre for Digital music, Queen Mary University of London, London, UK, 2006.

Definition in file pitch.h.

Function Documentation

◆ aubio_pitch_do()

void aubio_pitch_do ( aubio_pitch_t o,
const fvec_t in,
fvec_t out 
)

execute pitch detection on an input signal frame

Parameters
opitch detection object as returned by new_aubio_pitch()
ininput signal of size [hop_size]
outoutput pitch candidates of size [1]
Examples
examples/aubiopitch.c, and pitch/test-pitch.c.

◆ aubio_pitch_get_confidence()

smpl_t aubio_pitch_get_confidence ( aubio_pitch_t o)

get the current confidence

Parameters
opitch detection object as returned by new_aubio_pitch()
Returns
the current confidence of the pitch algorithm

◆ aubio_pitch_get_silence()

smpl_t aubio_pitch_get_silence ( aubio_pitch_t o)

set the silence threshold of the pitch detection object

Parameters
opitch detection object as returned by new_aubio_pitch()
Returns
level threshold under which pitch should be ignored, in dB

◆ aubio_pitch_get_tolerance()

smpl_t aubio_pitch_get_tolerance ( aubio_pitch_t o)

get yin or yinfft tolerance threshold

Parameters
opitch detection object as returned by new_aubio_pitch()
Returns
tolerance (default is 0.15 for yin and 0.85 for yinfft)

◆ aubio_pitch_set_silence()

uint_t aubio_pitch_set_silence ( aubio_pitch_t o,
smpl_t  silence 
)

set the silence threshold of the pitch detection object

Parameters
opitch detection object as returned by new_aubio_pitch()
silencelevel threshold under which pitch should be ignored, in dB
Returns
0 if successfull, non-zero otherwise
Examples
examples/aubiopitch.c, and pitch/test-pitch.c.

◆ aubio_pitch_set_tolerance()

uint_t aubio_pitch_set_tolerance ( aubio_pitch_t o,
smpl_t  tol 
)

change yin or yinfft tolerance threshold

Parameters
opitch detection object as returned by new_aubio_pitch()
toltolerance default is 0.15 for yin and 0.85 for yinfft
Examples
examples/aubiopitch.c, and pitch/test-pitch.c.

◆ aubio_pitch_set_unit()

uint_t aubio_pitch_set_unit ( aubio_pitch_t o,
const char_t mode 
)

set the output unit of the pitch detection object

Parameters
opitch detection object as returned by new_aubio_pitch()
modeset pitch units for output

mode can be one of "Hz", "midi", "cent", or "bin". Defaults to "Hz".

Returns
0 if successfull, non-zero otherwise
Examples
examples/aubiopitch.c, and pitch/test-pitch.c.

◆ del_aubio_pitch()

void del_aubio_pitch ( aubio_pitch_t o)

deletion of the pitch detection object

Parameters
opitch detection object as returned by new_aubio_pitch()
Examples
examples/aubiopitch.c, and pitch/test-pitch.c.

◆ new_aubio_pitch()

aubio_pitch_t* new_aubio_pitch ( const char_t method,
uint_t  buf_size,
uint_t  hop_size,
uint_t  samplerate 
)

creation of the pitch detection object

Parameters
methodset pitch detection algorithm
buf_sizesize of the input buffer to analyse
hop_sizestep size between two consecutive analysis instant
sampleratesampling rate of the signal
Returns
newly created aubio_pitch_t
Examples
examples/aubiopitch.c, and pitch/test-pitch.c.