aubio  0.4.9
Functions
filterbank_mel.h File Reference

Filterbank object coefficients initialization. More...

Go to the source code of this file.

Functions

uint_t aubio_filterbank_set_triangle_bands (aubio_filterbank_t *fb, const fvec_t *freqs, smpl_t samplerate)
 filterbank initialization with triangular and overlapping bands More...
 
uint_t aubio_filterbank_set_mel_coeffs_slaney (aubio_filterbank_t *fb, smpl_t samplerate)
 filterbank initialization for Mel filters using Slaney's coefficients More...
 
uint_t aubio_filterbank_set_mel_coeffs (aubio_filterbank_t *fb, smpl_t samplerate, smpl_t fmin, smpl_t fmax)
 Mel filterbank initialization. More...
 
uint_t aubio_filterbank_set_mel_coeffs_htk (aubio_filterbank_t *fb, smpl_t samplerate, smpl_t fmin, smpl_t fmax)
 Mel filterbank initialization. More...
 

Detailed Description

Filterbank object coefficients initialization.

Functions to create set the aubio_filterbank_t coefficients to

Definition in file filterbank_mel.h.

Function Documentation

◆ aubio_filterbank_set_mel_coeffs()

uint_t aubio_filterbank_set_mel_coeffs ( aubio_filterbank_t fb,
smpl_t  samplerate,
smpl_t  fmin,
smpl_t  fmax 
)

Mel filterbank initialization.

Parameters
fbfilterbank object
samplerateaudio sampling rate
fminstart frequency, in Hz
fmaxend frequency, in Hz

The filterbank will be initialized with bands linearly spaced in the mel scale, from fmin to fmax.

References

Malcolm Slaney, Auditory Toolbox Version 2, Technical Report #1998-010 https://engineering.purdue.edu/~malcolm/interval/1998-010/

◆ aubio_filterbank_set_mel_coeffs_htk()

uint_t aubio_filterbank_set_mel_coeffs_htk ( aubio_filterbank_t fb,
smpl_t  samplerate,
smpl_t  fmin,
smpl_t  fmax 
)

Mel filterbank initialization.

Parameters
fbfilterbank object
samplerateaudio sampling rate
fminstart frequency, in Hz
fmaxend frequency, in Hz

The bank of filters will be initalized to to cover linearly spaced bands in the Htk mel scale, from fmin to fmax.

References

Douglas O'Shaughnessy (1987). Speech communication: human and machine. Addison-Wesley. p. 150. ISBN 978-0-201-16520-3.

HTK Speech Recognition Toolkit: http://htk.eng.cam.ac.uk/

◆ aubio_filterbank_set_mel_coeffs_slaney()

uint_t aubio_filterbank_set_mel_coeffs_slaney ( aubio_filterbank_t fb,
smpl_t  samplerate 
)

filterbank initialization for Mel filters using Slaney's coefficients

Parameters
fbfilterbank object
samplerateaudio sampling rate, in Hz

The filter coefficients are built to match exactly Malcolm Slaney's Auditory Toolbox implementation (see file mfcc.m). The number of filters should be 40.

References

Malcolm Slaney, Auditory Toolbox Version 2, Technical Report #1998-010 https://engineering.purdue.edu/~malcolm/interval/1998-010/

Examples:
spectral/test-filterbank_mel.c.

◆ aubio_filterbank_set_triangle_bands()

uint_t aubio_filterbank_set_triangle_bands ( aubio_filterbank_t fb,
const fvec_t freqs,
smpl_t  samplerate 
)

filterbank initialization with triangular and overlapping bands

Parameters
fbfilterbank object
freqsarbitrary array of boundary frequencies
samplerateaudio sampling rate

This function computes the coefficients of the filterbank based on the boundaries found in freqs, in Hz, and using triangular overlapping bands.