ref: a4bd8d656612f7dff56090aabf6f3f26daed36c2
dir: /src/spectral/phasevoc.c/
/*
Copyright (C) 2003-2014 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 "fvec.h"
#include "cvec.h"
#include "mathutils.h"
#include "spectral/fft.h"
#include "spectral/phasevoc.h"
/** phasevocoder internal object */
struct _aubio_pvoc_t {
uint_t win_s; /** grain length */
uint_t hop_s; /** overlap step */
aubio_fft_t * fft; /** fft object */
fvec_t * data; /** current input grain, [win_s] frames */
fvec_t * dataold; /** memory of past grain, [win_s-hop_s] frames */
fvec_t * synth; /** current output grain, [win_s] frames */
fvec_t * synthold; /** memory of past grain, [win_s-hop_s] frames */
fvec_t * w; /** grain window [win_s] */
uint_t start; /** where to start additive synthesis */
uint_t end; /** where to end it */
smpl_t scale; /** scaling factor for synthesis */
uint_t end_datasize; /** size of memory to end */
uint_t hop_datasize; /** size of memory to hop_s */
};
/** returns data and dataold slided by hop_s */
static void aubio_pvoc_swapbuffers(aubio_pvoc_t *pv, const fvec_t *new);
/** do additive synthesis from 'old' and 'cur' */
static void aubio_pvoc_addsynth(aubio_pvoc_t *pv, fvec_t * synthnew);
void aubio_pvoc_do(aubio_pvoc_t *pv, const fvec_t * datanew, cvec_t *fftgrain) {
/* slide */
aubio_pvoc_swapbuffers(pv, datanew);
/* windowing */
fvec_weight(pv->data, pv->w);
/* shift */
fvec_shift(pv->data);
/* calculate fft */
aubio_fft_do (pv->fft,pv->data,fftgrain);
}
void aubio_pvoc_rdo(aubio_pvoc_t *pv,cvec_t * fftgrain, fvec_t * synthnew) {
/* calculate rfft */
aubio_fft_rdo(pv->fft,fftgrain,pv->synth);
/* unshift */
fvec_ishift(pv->synth);
/* windowing */
// if overlap = 50%, do not apply window (identity)
if (pv->hop_s * 2 < pv->win_s) {
fvec_weight(pv->synth, pv->w);
}
/* additive synthesis */
aubio_pvoc_addsynth(pv, synthnew);
}
aubio_pvoc_t * new_aubio_pvoc (uint_t win_s, uint_t hop_s) {
aubio_pvoc_t * pv = AUBIO_NEW(aubio_pvoc_t);
/* if (win_s < 2*hop_s) {
AUBIO_WRN("Hop size bigger than half the window size!\n");
} */
if ((sint_t)hop_s < 1) {
AUBIO_ERR("pvoc: got hop_size %d, but can not be < 1\n", hop_s);
goto beach;
} else if ((sint_t)win_s < 2) {
AUBIO_ERR("pvoc: got buffer_size %d, but can not be < 2\n", win_s);
goto beach;
} else if (win_s < hop_s) {
AUBIO_ERR("pvoc: hop size (%d) is larger than win size (%d)\n", hop_s, win_s);
goto beach;
}
pv->fft = new_aubio_fft (win_s);
if (pv->fft == NULL) {
goto beach;
}
/* remember old */
pv->data = new_fvec (win_s);
pv->synth = new_fvec (win_s);
/* new input output */
if (win_s > hop_s) {
pv->dataold = new_fvec (win_s-hop_s);
pv->synthold = new_fvec (win_s-hop_s);
} else {
pv->dataold = new_fvec (1);
pv->synthold = new_fvec (1);
}
pv->w = new_aubio_window ("hanningz", win_s);
pv->hop_s = hop_s;
pv->win_s = win_s;
/* more than 50% overlap, overlap anyway */
if (win_s < 2 * hop_s) pv->start = 0;
/* less than 50% overlap, reset latest grain trail */
else pv->start = win_s - hop_s - hop_s;
if (win_s > hop_s) pv->end = win_s - hop_s;
else pv->end = 0;
pv->end_datasize = pv->end * sizeof(smpl_t);
pv->hop_datasize = pv->hop_s * sizeof(smpl_t);
// for reconstruction with 75% overlap
if (win_s == hop_s * 4) {
pv->scale = 2./3.;
} else if (win_s == hop_s * 8) {
pv->scale = 1./3.;
} else if (win_s == hop_s * 2) {
pv->scale = 1.;
} else {
pv->scale = .5;
}
return pv;
beach:
AUBIO_FREE (pv);
return NULL;
}
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_fvec(pv->w);
del_aubio_fft(pv->fft);
AUBIO_FREE(pv);
}
static void aubio_pvoc_swapbuffers(aubio_pvoc_t *pv, const fvec_t *new)
{
/* some convenience pointers */
smpl_t * data = pv->data->data;
smpl_t * dataold = pv->dataold->data;
smpl_t * datanew = new->data;
#ifndef HAVE_MEMCPY_HACKS
uint_t i;
for (i = 0; i < pv->end; i++)
data[i] = dataold[i];
for (i = 0; i < pv->hop_s; i++)
data[pv->end + i] = datanew[i];
for (i = 0; i < pv->end; i++)
dataold[i] = data[i + pv->hop_s];
#else
memcpy(data, dataold, pv->end_datasize);
data += pv->end;
memcpy(data, datanew, pv->hop_datasize);
data -= pv->end;
data += pv->hop_s;
memcpy(dataold, data, pv->end_datasize);
#endif
}
static void aubio_pvoc_addsynth(aubio_pvoc_t *pv, fvec_t *synth_new)
{
uint_t i;
/* some convenience pointers */
smpl_t * synth = pv->synth->data;
smpl_t * synthold = pv->synthold->data;
smpl_t * synthnew = synth_new->data;
/* put new result in synthnew */
for (i = 0; i < pv->hop_s; i++)
synthnew[i] = synth[i] * pv->scale;
/* no overlap, nothing else to do */
if (pv->end == 0) return;
/* add new synth to old one */
for (i = 0; i < pv->hop_s; i++)
synthnew[i] += synthold[i];
/* shift synthold */
for (i = 0; i < pv->start; i++)
synthold[i] = synthold[i + pv->hop_s];
/* erase last frame in synthold */
for (i = pv->start; i < pv->end; i++)
synthold[i] = 0.;
/* additive synth */
for (i = 0; i < pv->end; i++)
synthold[i] += synth[i + pv->hop_s] * pv->scale;
}