ref: 73eaa2eac589b64976cca5673cdcea7f3c831e0f
dir: /src/mfcc.c/
/*
Copyright (C) 2006 Amaury Hazan
Ported to aubio from LibXtract
http://libxtract.sourceforge.net/
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include "aubio_priv.h"
#include "sample.h"
#include "fft.h"
#include "filterbank.h"
#include "mfcc.h"
#include "math.h"
/** Internal structure for mfcc object **/
struct aubio_mfcc_t_{
/** grain length */
uint_t win_s;
/** sample rate (needed?) */
uint_t samplerate;
/** number of channels */
uint_t channels;
/** filter bank */
aubio_filterbank_t * fb;
/** number of coefficients (= fb->n_filters/2 +1) */
uint_t n_coefs;
/** lowest frequency for filters */
smpl_t lowfreq;
/** highest frequency for filters */
smpl_t highfreq;
/** input buffer for dct * [fb->n_filters] */
fvec_t * in_dct;
/** fft object for dct */
aubio_mfft_t * fft_dct;
/** output buffer for dct */
cvec_t * fftgrain_dct;
};
aubio_mfcc_t * new_aubio_mfcc (uint_t win_s, uint_t samplerate ,uint_t n_coefs, smpl_t lowfreq, smpl_t highfreq, uint_t channels){
/** allocating space for mfcc object */
aubio_mfcc_t * mfcc = AUBIO_NEW(aubio_mfcc_t);
mfcc->win_s=win_s;
mfcc->samplerate=samplerate;
mfcc->channels=channels;
mfcc->n_coefs=n_coefs;
mfcc->lowfreq=lowfreq;
mfcc->highfreq=highfreq;
/** filterbank allocation */
//we need (n_coefs-1)*2 filters to obtain n_coefs coefficients after dct
mfcc->fb=new_aubio_filterbank((n_coefs-1)*2, mfcc->win_s);
/** allocating space for fft object (used for dct) */
mfcc->fft_dct=new_aubio_mfft(mfcc->win_s, 1);
/** allocating buffers */
mfcc->in_dct=new_fvec(mfcc->win_s, 1);
mfcc->fftgrain_dct=new_cvec(mfcc->fb->n_filters, 1);
/** populating the filterbank */
aubio_filterbank_mfcc_init(mfcc->fb, (mfcc->samplerate)/2, XTRACT_EQUAL_GAIN, mfcc->lowfreq, mfcc->highfreq);
return mfcc;
};
void del_aubio_mfcc(aubio_mfcc_t *mf){
/** deleting filterbank */
del_aubio_filterbank(mf->fb);
/** deleting mfft object */
del_aubio_mfft(mf->fft_dct);
/** deleting buffers */
del_fvec(mf->in_dct);
del_cvec(mf->fftgrain_dct);
/** deleting mfcc object */
AUBIO_FREE(mf);
}
// Computation
void aubio_mfcc_do(aubio_mfcc_t * mf, cvec_t *in, fvec_t *out){
aubio_filterbank_t *f = mf->fb;
uint_t n, filter_cnt;
for(filter_cnt = 0; filter_cnt < f->n_filters; filter_cnt++){
mf->in_dct->data[0][filter_cnt] = 0.f;
for(n = 0; n < mf->win_s; n++){
mf->in_dct->data[0][filter_cnt] += in->norm[0][n] * f->filters[filter_cnt]->data[0][n];
}
mf->in_dct->data[0][filter_cnt] = LOG(mf->in_dct->data[0][filter_cnt] < XTRACT_LOG_LIMIT ? XTRACT_LOG_LIMIT : mf->in_dct->data[0][filter_cnt]);
}
//TODO: check that zero padding
// the following line seems useless since the in_dct buffer has the correct size
//for(n = filter + 1; n < N; n++) result[n] = 0;
aubio_dct_do(mf, mf->in_dct, out);
//return XTRACT_SUCCESS;
}
void aubio_dct_do(aubio_mfcc_t * mf, fvec_t *in, fvec_t *out){
//fvec_t * momo = new_fvec(20, 1);
//momo->data = data;
//compute mag spectrum
aubio_mfft_do (mf->fft_dct, in, mf->fftgrain_dct);
int i;
//extract real part of fft grain
for(i=0; i<mf->n_coefs ;i++){
out->data[0][i]= mf->fftgrain_dct->norm[0][i]*COS(mf->fftgrain_dct->phas[0][i]);
}
//return XTRACT_SUCCESS;
}
///////// OLD CODE
// int aubio_mfcc_do(const float *data, const int N, const void *argv, float *result, aubio_mfft_t * fft_dct, cvec_t * fftgrain_dct){
//
// aubio_mel_filter *f;
// uint_t n, filter;
//
// f = (aubio_mel_filter *)argv;
// printf("%d",f->n_filters);
//
// for(filter = 0; filter < f->n_filters; filter++){
// result[filter] = 0.f;
// for(n = 0; n < N; n++){
// result[filter] += data[n] * f->filters[filter][n];
// }
// result[filter] = LOG(result[filter] < XTRACT_LOG_LIMIT ? XTRACT_LOG_LIMIT : result[filter]);
// }
//
// //TODO: check that zero padding
// for(n = filter + 1; n < N; n++) result[n] = 0;
//
// aubio_dct_do(result, f->n_filters, NULL, result, fft_dct, fftgrain_dct);
//
// return XTRACT_SUCCESS;
// }
// Added last two arguments to be able to pass from example
// int aubio_dct_do(const float *data, const int N, const void *argv, float *result, aubio_mfft_t * fft_dct, cvec_t * fftgrain_dct){
//
//
// //call aubio p_voc in dct setting
//
// //TODO: fvec as input? Remove data length, N?
//
// fvec_t * momo = new_fvec(20, 1);
// momo->data = data;
//
// //compute mag spectrum
// aubio_mfft_do (fft_dct, data, fftgrain_dct);
//
// int i;
// //extract real part of fft grain
// for(i=0; i<N ;i++){
// result[i]= fftgrain_dct->norm[0][i]*COS(fftgrain_dct->phas[0][i]);
// }
//
//
// return XTRACT_SUCCESS;
// }