ref: 23a44c142a08aeedde8c358f9e116ccaf86db4d2
dir: /src/filter.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. */ /* Requires lsmp_t to be long or double. float will NOT give reliable * results */ #include "aubio_priv.h" #include "sample.h" #include "mathutils.h" #include "filter.h" struct _aubio_filter_t { uint_t order; lsmp_t * a; lsmp_t * b; lsmp_t * y; lsmp_t * x; }; /* bug: mono only */ void aubio_filter_do(aubio_filter_t * f, fvec_t * in) { uint_t i,j,l, order = f->order; lsmp_t *x = f->x; lsmp_t *y = f->y; lsmp_t *a = f->a; lsmp_t *b = f->b; i=0;//for (i=0;i<in->channels;i++) { for (j = 0; j < in->length; j++) { /* new input */ //AUBIO_DBG("befor %f\t", in->data[i][j]); x[0] = in->data[i][j]; y[0] = b[0] * x[0]; for (l=1;l<order; l++) { y[0] += b[l] * x[l]; y[0] -= a[l] * y[l]; } /* + 1e-37; for denormal ? */ /* new output */ in->data[i][j] = y[0]; //AUBIO_DBG("after %f\n", in->data[i][j]); /* store states for next sample */ for (l=order-1; l>0; l--){ x[l] = x[l-1]; y[l] = y[l-1]; } } /* store states for next buffer */ f->x = x; f->y = y; //} } void aubio_filter_do_outplace(aubio_filter_t * f, fvec_t * in, fvec_t * out) { uint_t i,j,l, order = f->order; lsmp_t *x = f->x; lsmp_t *y = f->y; lsmp_t *a = f->a; lsmp_t *b = f->b; i=0; // works in mono only !!! //for (i=0;i<in->channels;i++) { for (j = 0; j < in->length; j++) { /* new input */ x[0] = in->data[i][j]; y[0] = b[0] * x[0]; for (l=1;l<order; l++) { y[0] += b[l] * x[l]; y[0] -= a[l] * y[l]; } // + 1e-37; /* new output */ out->data[i][j] = y[0]; /* store for next sample */ for (l=order-1; l>0; l--){ x[l] = x[l-1]; y[l] = y[l-1]; } } /* store for next run */ f->x = x; f->y = y; //} } /* * * despite mirroring, end effects destroy both phse and amplitude. the longer * the buffer, the less affected they are. * * replacing with zeros clicks. * * seems broken for order > 4 (see biquad_do_filtfilt for audible one) */ void aubio_filter_do_filtfilt(aubio_filter_t * f, fvec_t * in, fvec_t * tmp) { uint_t j,i=0; uint_t length = in->length; //uint_t order = f->order; //lsmp_t mir; /* mirroring */ //mir = 2*in->data[i][0]; //for (j=1;j<order;j++) //f->x[j] = 0.;//mir - in->data[i][order-j]; /* apply filtering */ aubio_filter_do(f,in); /* invert */ for (j = 0; j < length; j++) tmp->data[i][length-j-1] = in->data[i][j]; /* mirror inverted */ //mir = 2*tmp->data[i][0]; //for (j=1;j<order;j++) //f->x[j] = 0.;//mir - tmp->data[i][order-j]; /* apply filtering on inverted */ aubio_filter_do(f,tmp); /* invert back */ for (j = 0; j < length; j++) in->data[i][j] = tmp->data[i][length-j-1]; } aubio_filter_t * new_aubio_adsgn_filter(uint_t samplerate) { aubio_filter_t * f = new_aubio_filter(samplerate, 7); lsmp_t * a = f->a; lsmp_t * b = f->b; /* uint_t l; */ /* for now, 44100, adsgn */ a[0] = 1.00000000000000000000000000000000000000000000000000000; a[1] = -4.01957618111583236952810693765059113502502441406250000; a[2] = 6.18940644292069386267485242569819092750549316406250000; a[3] = -4.45319890354411640487342083360999822616577148437500000; a[4] = 1.42084294962187751565352300531230866909027099609375000; a[5] = -0.14182547383030480458998567883099894970655441284179688; a[6] = 0.00435117723349511334451911181986361043527722358703613; b[0] = 0.25574112520425740235907596797915175557136535644531250; b[1] = -0.51148225040851391653973223583307117223739624023437500; b[2] = -0.25574112520426162120656954357400536537170410156250000; b[3] = 1.02296450081703405032840237254276871681213378906250000; b[4] = -0.25574112520426051098354491841746494174003601074218750; b[5] = -0.51148225040851369449512731080176308751106262207031250; b[6] = 0.25574112520425729133677350546349771320819854736328125; /* DBG: filter coeffs at creation time */ /* for (l=0; l<f->order; l++){ AUBIO_DBG("a[%d]=\t%1.16f\tb[%d]=\t%1.16f\n",l,a[l],l,b[l]); } */ f->a = a; f->b = b; return f; } aubio_filter_t * new_aubio_cdsgn_filter(uint_t samplerate) { aubio_filter_t * f = new_aubio_filter(samplerate, 5); lsmp_t * a = f->a; lsmp_t * b = f->b; /* uint_t l; */ /* for now, 44100, cdsgn */ a[0] = 1.000000000000000000000000000000000000000000000000000000000000; a[1] = -2.134674963687040794013682898366823792457580566406250000000000; a[2] = 1.279333533236063358273781886964570730924606323242187500000000; a[3] = -0.149559846089396208945743182994192466139793395996093750000000; a[4] = 0.004908700174624848651394604104325480875559151172637939453125; b[0] = 0.217008561949218803377448239189106971025466918945312500000000; b[1] = -0.000000000000000222044604925031308084726333618164062500000000; b[2] = -0.434017123898438272888711253472138196229934692382812500000000; b[3] = 0.000000000000000402455846426619245903566479682922363281250000; b[4] = 0.217008561949218969910901932962588034570217132568359375000000; /* DBG: filter coeffs at creation time */ /* for (l=0; l<f->order; l++){ AUBIO_DBG("a[%d]=\t%1.16f\tb[%d]=\t%1.16f\n",l,a[l],l,b[l]); } */ f->a = a; f->b = b; return f; } aubio_filter_t * new_aubio_filter(uint_t samplerate, uint_t order) { aubio_filter_t * f = AUBIO_NEW(aubio_filter_t); lsmp_t * x = f->x; lsmp_t * y = f->y; lsmp_t * a = f->a; lsmp_t * b = f->b; uint_t l; f->order = order; a = AUBIO_ARRAY(lsmp_t,f->order); b = AUBIO_ARRAY(lsmp_t,f->order); x = AUBIO_ARRAY(lsmp_t,f->order); y = AUBIO_ARRAY(lsmp_t,f->order); /* initial states to zeros */ for (l=0; l<f->order; l++){ x[l] = 0.; y[l] = 0.; } f->x = x; f->y = y; f->a = a; f->b = b; return f; }