ref: 32669d979d3b61b852591e63f7ea818e6a7e286b
dir: /src/biquad.c/
/* Copyright (C) 2003 Paul Brossier 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 "mathutils.h" #include "biquad.h" /** \note this file needs to be in double or more less precision would lead to large * errors in the output */ struct _aubio_biquad_t { lsmp_t a2; lsmp_t a3; lsmp_t b1; lsmp_t b2; lsmp_t b3; lsmp_t o1; lsmp_t o2; lsmp_t i1; lsmp_t i2; }; void aubio_biquad_do(aubio_biquad_t * b, fvec_t * in) { uint_t i,j; lsmp_t i1 = b->i1; lsmp_t i2 = b->i2; lsmp_t o1 = b->o1; lsmp_t o2 = b->o2; lsmp_t a2 = b->a2; lsmp_t a3 = b->a3; lsmp_t b1 = b->b1; lsmp_t b2 = b->b2; lsmp_t b3 = b->b3; i=0; // works in mono only !!! //for (i=0;i<in->channels;i++) { for (j = 0; j < in->length; j++) { lsmp_t i0 = in->data[i][j]; lsmp_t o0 = b1 * i0 + b2 * i1 + b3 * i2 - a2 * o1 - a3 * o2;// + 1e-37; in->data[i][j] = o0; i2 = i1; i1 = i0; o2 = o1; o1 = o0; } b->i2 = i2; b->i1 = i1; b->o2 = o2; b->o1 = o1; //} } void aubio_biquad_do_filtfilt(aubio_biquad_t * b, fvec_t * in, fvec_t * tmp) { uint_t j,i=0; uint_t length = in->length; lsmp_t mir; /* mirroring */ mir = 2*in->data[i][0]; b->i1 = mir - in->data[i][2]; b->i2 = mir - in->data[i][1]; /* apply filtering */ aubio_biquad_do(b,in); /* invert */ for (j = 0; j < length; j++) tmp->data[i][length-j-1] = in->data[i][j]; /* mirror again */ mir = 2*tmp->data[i][0]; b->i1 = mir - tmp->data[i][2]; b->i2 = mir - tmp->data[i][1]; /* apply filtering */ aubio_biquad_do(b,tmp); /* invert back */ for (j = 0; j < length; j++) in->data[i][j] = tmp->data[i][length-j-1]; } aubio_biquad_t * new_aubio_biquad( lsmp_t b1, lsmp_t b2, lsmp_t b3, lsmp_t a2, lsmp_t a3) { aubio_biquad_t * b = AUBIO_NEW(aubio_biquad_t); b->a2 = a2; b->a3 = a3; b->b1 = b1; b->b2 = b2; b->b3 = b3; b->i1 = 0.; b->i2 = 0.; b->o1 = 0.; b->o2 = 0.; return b; }