Logo Search packages:      
Sourcecode: aubio version File versions  Download package

phasevoc.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 "fft.h"
#include "mathutils.h"
#include "phasevoc.h"

/** phasevocoder internal object */
00027 struct _aubio_pvoc_t {
      /** grain length */
00029       uint_t win_s;
      /** overlap step */
00031       uint_t hop_s;
      /** number of channels */
00033       uint_t channels;
      /** spectral data */
00035       aubio_mfft_t * fft;
      /**cur output grain           [win_s] */
00037       fvec_t * synth;          
      /**last input frame           [win_s-hop_s] */
00039       fvec_t * synthold; 
      /**current input grain        [win_s] */
00041       fvec_t * data;           
      /**last input frame           [win_s-hop_s] */
00043       fvec_t * dataold;  
      /** grain window        [win_s] */
00045       float * w;
};


/** returns data and dataold slided by hop_s */
static void aubio_pvoc_swapbuffers(
            smpl_t * data,
            smpl_t * dataold,
            const smpl_t * datanew,
            uint_t win_s, uint_t hop_s);
/** do additive synthesis from 'old' and 'cur' */
static void aubio_pvoc_addsynth(
            const smpl_t * synth,
            smpl_t * synthold,
            smpl_t * synthnew, 
            uint_t win_s, uint_t hop_s);


00063 void aubio_pvoc_do(aubio_pvoc_t *pv, fvec_t * datanew, cvec_t *fftgrain) {
      uint_t i,j;
      for (i=0; i<pv->channels; i++) {
            /* slide  */
            aubio_pvoc_swapbuffers(pv->data->data[i],pv->dataold->data[i],
                        datanew->data[i],pv->win_s,pv->hop_s);
            /* windowing */
            for (j=0; j<pv->win_s; j++) pv->data->data[i][j] *= pv->w[j];
        }
        /* shift */
        vec_shift(pv->data);
      /* calculate fft */
        aubio_mfft_do (pv->fft,pv->data,fftgrain);
}

00078 void aubio_pvoc_rdo(aubio_pvoc_t *pv,cvec_t * fftgrain, fvec_t * synthnew) {
      uint_t i,j;
      /* calculate rfft */
        aubio_mfft_rdo(pv->fft,fftgrain,pv->synth);
        /* unshift */
        vec_shift(pv->synth);
      for (i=0; i<pv->channels; i++) {
            for (j=0; j<pv->win_s; j++) pv->synth->data[i][j] *= pv->w[j];
            aubio_pvoc_addsynth(pv->synth->data[i],pv->synthold->data[i],
                        synthnew->data[i],pv->win_s,pv->hop_s);
      }
}

00091 aubio_pvoc_t * new_aubio_pvoc (uint_t win_s, uint_t hop_s, uint_t channels) {
      aubio_pvoc_t * pv = AUBIO_NEW(aubio_pvoc_t);

      if (win_s < 2*hop_s) {
            AUBIO_ERR("Hop size bigger than half the window size!\n");
            AUBIO_ERR("Resetting hop size to half the window size.\n");
                hop_s = win_s / 2;
      }

      if (hop_s < 1) {
            AUBIO_ERR("Hop size is smaller than 1!\n");
            AUBIO_ERR("Resetting hop size to half the window size.\n");
                hop_s = win_s / 2;
      }
      
      pv->fft      = new_aubio_mfft(win_s,channels);

      /* remember old */
      pv->data     = new_fvec (win_s, channels);
      pv->synth    = new_fvec (win_s, channels);

      /* new input output */
      pv->dataold  = new_fvec  (win_s-hop_s, channels);
      pv->synthold = new_fvec (win_s-hop_s, channels);
      pv->w        = AUBIO_ARRAY(smpl_t,win_s);
      aubio_window(pv->w,win_s,aubio_win_hanningz);

      pv->channels = channels;
      pv->hop_s    = hop_s;
      pv->win_s    = win_s;

      return pv;
}

00125 void del_aubio_pvoc(aubio_pvoc_t *pv) {
      del_fvec(pv->data);
      del_fvec(pv->synth);
      del_fvec(pv->dataold);
      del_fvec(pv->synthold);
      del_aubio_mfft(pv->fft);
      AUBIO_FREE(pv->w);
      AUBIO_FREE(pv);
}

static void aubio_pvoc_swapbuffers(smpl_t * data, smpl_t * dataold, 
                const smpl_t * datanew, uint_t win_s, uint_t hop_s)
{
      uint_t i;
      for (i=0;i<win_s-hop_s;i++)
            data[i] = dataold[i];
      for (i=0;i<hop_s;i++)
            data[win_s-hop_s+i] = datanew[i];
      for (i=0;i<win_s-hop_s;i++)
            dataold[i] = data[i+hop_s];
}

static void aubio_pvoc_addsynth(const smpl_t * synth, smpl_t * synthold, 
                smpl_t * synthnew, uint_t win_s, uint_t hop_s)
{
      uint_t i;
      smpl_t scale = 2*hop_s/(win_s+.0);
      /* add new synth to old one and put result in synthnew */
      for (i=0;i<hop_s;i++)                                 
            synthnew[i] = synthold[i]+synth[i]*scale;
      /* shift synthold */
      for (i=0;i<win_s-2*hop_s;i++) 
            synthold[i] = synthold[i+hop_s];
      /* erase last frame in synthold */
      for (i=win_s-hop_s;i<win_s;i++)     
            synthold[i-hop_s]=0.;
      /* additive synth */
      for (i=0;i<win_s-hop_s;i++)   
            synthold[i] += synth[i+hop_s]*scale;
}


Generated by  Doxygen 1.6.0   Back to index