source: src/temporal/c_weighting.c @ 1cc007c

/*
  Copyright (C) 2003-2009 Paul Brossier <piem@aubio.org>

  This file is part of aubio.

  aubio 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 3 of the License, or
  (at your option) any later version.

  aubio 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 aubio.  If not, see <http://www.gnu.org/licenses/>.

*/

#include "aubio_priv.h"
#include "types.h"
#include "fvec.h"
#include "lvec.h"
#include "temporal/filter.h"
#include "temporal/c_weighting.h"

void aubio_filter_set_c_weighting (aubio_filter_t * f) {

  uint_t samplerate = aubio_filter_get_samplerate (f);
  lvec_t * bs = aubio_filter_get_feedforward (f);
  lvec_t * as = aubio_filter_get_feedback (f);
  lsmp_t *b = bs->data[0], *a = as->data[0];
  uint_t order = aubio_filter_get_order (f);

  if ( order != 5 ) {
    AUBIO_ERROR ( "order of C-weighting filter must be 5, not %d\n", order );
    return;
  }

  /* select coefficients according to sampling frequency */
  switch ( samplerate ) {

    case 8000:
      b[0] =  6.782173932405135552414776611840352416038513183593750000e-01;
      b[1] =  0.000000000000000000000000000000000000000000000000000000e+00;
      b[2] = -1.356434786481027110482955322368070483207702636718750000e+00;
      b[3] =  0.000000000000000000000000000000000000000000000000000000e+00;
      b[4] =  6.782173932405135552414776611840352416038513183593750000e-01;
      a[0] =  1.000000000000000000000000000000000000000000000000000000e+00;
      a[1] = -6.589092811505605773447769024642184376716613769531250000e-01;
      a[2] = -1.179445664897062595599663836765103042125701904296875000e+00;
      a[3] =  4.243329729632123736848825501510873436927795410156250000e-01;
      a[4] =  4.147270002091348328754349950031610205769538879394531250e-01;
      break;

    case 16000:
      b[0] =  4.971057193673903418229542694461997598409652709960937500e-01;
      b[1] =  0.000000000000000000000000000000000000000000000000000000e+00;
      b[2] = -9.942114387347806836459085388923995196819305419921875000e-01;
      b[3] =  0.000000000000000000000000000000000000000000000000000000e+00;
      b[4] =  4.971057193673903418229542694461997598409652709960937500e-01;
      a[0] =  1.000000000000000000000000000000000000000000000000000000e+00;
      a[1] = -1.162322939286873690889478893950581550598144531250000000e+00;
      a[2] = -4.771961355734982701548574368644040077924728393554687500e-01;
      a[3] =  4.736145114694704227886745684372726827859878540039062500e-01;
      a[4] =  1.660337524309875301131711466950946487486362457275390625e-01;
      break;

    case 22050:
      b[0] =  4.033381299002754549754001800465630367398262023925781250e-01;
      b[1] =  0.000000000000000000000000000000000000000000000000000000e+00;
      b[2] = -8.066762598005509099508003600931260734796524047851562500e-01;
      b[3] =  0.000000000000000000000000000000000000000000000000000000e+00;
      b[4] =  4.033381299002754549754001800465630367398262023925781250e-01;
      a[0] =  1.000000000000000000000000000000000000000000000000000000e+00;
      a[1] = -1.449545371157945350404361306573264300823211669921875000e+00;
      a[2] = -1.030104190885922088583015465701464563608169555664062500e-02;
      a[3] =  3.881857047554073680828423675848171114921569824218750000e-01;
      a[4] =  7.171589940116777917022972133054281584918498992919921875e-02;
      break;

    case 44100:
      b[0] =  2.170085619492190254220531642204150557518005371093750000e-01;
      b[1] =  0.000000000000000000000000000000000000000000000000000000e+00;
      b[2] = -4.340171238984380508441063284408301115036010742187500000e-01;
      b[3] =  0.000000000000000000000000000000000000000000000000000000e+00;
      b[4] =  2.170085619492190254220531642204150557518005371093750000e-01;
      a[0] =  1.000000000000000000000000000000000000000000000000000000e+00;
      a[1] = -2.134674963687040794013682898366823792457580566406250000e+00;
      a[2] =  1.279333533236062692139967111870646476745605468750000000e+00;
      a[3] = -1.495598460893957093453821016737492755055427551269531250e-01;
      a[4] =  4.908700174624683852664386307651511742733418941497802734e-03;
      break;

    case 96000:
      b[0] =  8.182864044979756834585771230194950476288795471191406250e-02;
      b[1] =  0.000000000000000000000000000000000000000000000000000000e+00;
      b[2] = -1.636572808995951366917154246038990095257759094238281250e-01;
      b[3] =  0.000000000000000000000000000000000000000000000000000000e+00;
      b[4] =  8.182864044979756834585771230194950476288795471191406250e-02;
      a[0] =  1.000000000000000000000000000000000000000000000000000000e+00;
      a[1] = -2.856378516857566829401093855267390608787536621093750000e+00;
      a[2] =  2.897640237559524045707348705036565661430358886718750000e+00;
      a[3] = -1.225265958339703198376469117647502571344375610351562500e+00;
      a[4] =  1.840048283551226071530493300087982788681983947753906250e-01;
      break;

    case 192000:
      b[0] =  2.784755468532278815940728122768632601946592330932617188e-02;
      b[1] =  0.000000000000000000000000000000000000000000000000000000e+00;
      b[2] = -5.569510937064557631881456245537265203893184661865234375e-02;
      b[3] =  0.000000000000000000000000000000000000000000000000000000e+00;
      b[4] =  2.784755468532278815940728122768632601946592330932617188e-02;
      a[0] =  1.000000000000000000000000000000000000000000000000000000e+00;
      a[1] = -3.333298856144166322224009491037577390670776367187500000e+00;
      a[2] =  4.111467536240339448738723149290308356285095214843750000e+00;
      a[3] = -2.222889041651291641699117462849244475364685058593750000e+00;
      a[4] =  4.447204118126878991112960193277103826403617858886718750e-01;
      break;

    default:
      AUBIO_ERROR ( "sampling rate of C-weighting filter is %d, should be one of\
 8000, 16000, 22050, 44100, 96000, 192000.\n",  samplerate );
      break;

  }

}

aubio_filter_t * new_aubio_filter_c_weighting (uint_t samplerate, uint_t channels) {
  aubio_filter_t * f = new_aubio_filter(samplerate, 5, channels);
  aubio_filter_set_c_weighting (f);
  return f;
}