ref: 4a897680e34dc59aebc0dfa8076e38338fbe48e9
dir: /libcelt/bands.c/
/* (C) 2007 Jean-Marc Valin, CSIRO
*/
/*
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
- Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
- Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
- Neither the name of the Xiph.org Foundation nor the names of its
contributors may be used to endorse or promote products derived from
this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR
CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <math.h>
#include "bands.h"
#include "modes.h"
#include "vq.h"
#include "cwrs.h"
/* Applies a series of rotations so that pulses are spread like a two-sided expo
nential */
static void exp_rotation(float *X, int len, float theta, int dir)
{
int i;
float c, s;
c = cos(theta);
s = sin(theta);
if (dir > 0)
{
for (i=0;i<(len/2)-1;i++)
{
float x1, x2;
x1 = X[2*i];
x2 = X[2*i+2];
X[2*i] = c*x1 - s*x2;
X[2*i+2] = c*x2 + s*x1;
x1 = X[2*i+1];
x2 = X[2*i+3];
X[2*i+1] = c*x1 - s*x2;
X[2*i+3] = c*x2 + s*x1;
}
for (i=(len/2)-3;i>=0;i--)
{
float x1, x2;
x1 = X[2*i];
x2 = X[2*i+2];
X[2*i] = c*x1 - s*x2;
X[2*i+2] = c*x2 + s*x1;
x1 = X[2*i+1];
x2 = X[2*i+3];
X[2*i+1] = c*x1 - s*x2;
X[2*i+3] = c*x2 + s*x1;
}
} else {
for (i=0;i<(len/2)-2;i++)
{
float x1, x2;
x1 = X[2*i];
x2 = X[2*i+2];
X[2*i] = c*x1 + s*x2;
X[2*i+2] = c*x2 - s*x1;
x1 = X[2*i+1];
x2 = X[2*i+3];
X[2*i+1] = c*x1 + s*x2;
X[2*i+3] = c*x2 - s*x1;
}
for (i=(len/2)-2;i>=0;i--)
{
float x1, x2;
x1 = X[2*i];
x2 = X[2*i+2];
X[2*i] = c*x1 + s*x2;
X[2*i+2] = c*x2 - s*x1;
x1 = X[2*i+1];
x2 = X[2*i+3];
X[2*i+1] = c*x1 + s*x2;
X[2*i+3] = c*x2 - s*x1;
}
}
}
/* Compute the energy in each of the bands */
void compute_band_energies(const CELTMode *m, float *X, float *bank)
{
int i, B;
const int *eBands = m->eBands;
B = m->nbMdctBlocks*m->nbChannels;
for (i=0;i<m->nbEBands;i++)
{
int j;
bank[i] = 1e-10;
for (j=B*eBands[i];j<B*eBands[i+1];j++)
bank[i] += X[j]*X[j];
bank[i] = sqrt(bank[i]);
}
}
/* Normalise each band such that the energy is one. */
void normalise_bands(const CELTMode *m, float *X, float *bank)
{
int i, B;
const int *eBands = m->eBands;
B = m->nbMdctBlocks*m->nbChannels;
for (i=0;i<m->nbEBands;i++)
{
int j;
float x = 1.f/(1e-10+bank[i]);
for (j=B*eBands[i];j<B*eBands[i+1];j++)
X[j] *= x;
}
for (i=B*eBands[m->nbEBands];i<B*eBands[m->nbEBands+1];i++)
X[i] = 0;
}
/* De-normalise the energy to produce the synthesis from the unit-energy bands */
void denormalise_bands(const CELTMode *m, float *X, float *bank)
{
int i, B;
const int *eBands = m->eBands;
B = m->nbMdctBlocks*m->nbChannels;
for (i=0;i<m->nbEBands;i++)
{
int j;
float x = bank[i];
for (j=B*eBands[i];j<B*eBands[i+1];j++)
X[j] *= x;
}
for (i=B*eBands[m->nbEBands];i<B*eBands[m->nbEBands+1];i++)
X[i] = 0;
}
/* Compute the best gain for each "pitch band" */
void compute_pitch_gain(const CELTMode *m, float *X, float *P, float *gains, float *bank)
{
int i, B;
const int *eBands = m->eBands;
const int *pBands = m->pBands;
B = m->nbMdctBlocks*m->nbChannels;
float w[B*eBands[m->nbEBands]];
for (i=0;i<m->nbEBands;i++)
{
int j;
for (j=B*eBands[i];j<B*eBands[i+1];j++)
w[j] = bank[i];
}
for (i=0;i<m->nbPBands;i++)
{
float Sxy=0;
float Sxx = 0;
int j;
float gain;
for (j=B*pBands[i];j<B*pBands[i+1];j++)
{
Sxy += X[j]*P[j]*w[j];
Sxx += X[j]*X[j]*w[j];
}
gain = Sxy/(1e-10+Sxx);
//gain = Sxy/(2*(pbank[i+1]-pbank[i]));
//if (i<3)
//gain *= 1+.02*gain;
if (gain > .90)
gain = .90;
if (gain < 0.0)
gain = 0.0;
gains[i] = gain;
}
for (i=B*pBands[m->nbPBands];i<B*pBands[m->nbPBands+1];i++)
P[i] = 0;
}
/* Apply the (quantised) gain to each "pitch band" */
void pitch_quant_bands(const CELTMode *m, float *X, float *P, float *gains)
{
int i, B;
const int *pBands = m->pBands;
B = m->nbMdctBlocks*m->nbChannels;
for (i=0;i<m->nbPBands;i++)
{
int j;
for (j=B*pBands[i];j<B*pBands[i+1];j++)
P[j] *= gains[i];
//printf ("%f ", gain);
}
for (i=B*pBands[m->nbPBands];i<B*pBands[m->nbPBands+1];i++)
P[i] = 0;
}
void quant_bands(const CELTMode *m, float *X, float *P, ec_enc *enc)
{
int i, j, B;
const int *eBands = m->eBands;
B = m->nbMdctBlocks*m->nbChannels;
float norm[B*eBands[m->nbEBands+1]];
for (i=0;i<m->nbEBands;i++)
{
int q;
q = m->nbPulses[i];
if (q>0) {
float n = sqrt(B*(eBands[i+1]-eBands[i]));
alg_quant(X+B*eBands[i], B*(eBands[i+1]-eBands[i]), q, P+B*eBands[i], 0.7, enc);
for (j=B*eBands[i];j<B*eBands[i+1];j++)
norm[j] = X[j] * n;
//printf ("%f ", log2(ncwrs64(B*(eBands[i+1]-eBands[i]), q))/(B*(eBands[i+1]-eBands[i])));
//printf ("%f ", log2(ncwrs64(B*(eBands[i+1]-eBands[i]), q)));
} else {
float n = sqrt(B*(eBands[i+1]-eBands[i]));
copy_quant(X+B*eBands[i], B*(eBands[i+1]-eBands[i]), -q, norm, B, eBands[i], enc);
for (j=B*eBands[i];j<B*eBands[i+1];j++)
norm[j] = X[j] * n;
//printf ("%f ", (1+log2(eBands[i]-(eBands[i+1]-eBands[i]))+log2(ncwrs64(B*(eBands[i+1]-eBands[i]), -q)))/(B*(eBands[i+1]-eBands[i])));
//printf ("%f ", (1+log2(eBands[i]-(eBands[i+1]-eBands[i]))+log2(ncwrs64(B*(eBands[i+1]-eBands[i]), -q))));
}
}
//printf ("\n");
for (i=B*eBands[m->nbEBands];i<B*eBands[m->nbEBands+1];i++)
X[i] = 0;
}
void unquant_bands(const CELTMode *m, float *X, float *P, ec_dec *dec)
{
int i, j, B;
const int *eBands = m->eBands;
B = m->nbMdctBlocks*m->nbChannels;
float norm[B*eBands[m->nbEBands+1]];
for (i=0;i<m->nbEBands;i++)
{
int q;
q = m->nbPulses[i];
if (q>0) {
float n = sqrt(B*(eBands[i+1]-eBands[i]));
alg_unquant(X+B*eBands[i], B*(eBands[i+1]-eBands[i]), q, P+B*eBands[i], 0.7, dec);
for (j=B*eBands[i];j<B*eBands[i+1];j++)
norm[j] = X[j] * n;
} else {
float n = sqrt(B*(eBands[i+1]-eBands[i]));
for (j=B*eBands[i];j<B*eBands[i+1];j++)
X[j] = 0;
copy_unquant(X+B*eBands[i], B*(eBands[i+1]-eBands[i]), -q, norm, B, eBands[i], dec);
for (j=B*eBands[i];j<B*eBands[i+1];j++)
norm[j] = X[j] * n;
}
}
for (i=B*eBands[m->nbEBands];i<B*eBands[m->nbEBands+1];i++)
X[i] = 0;
}
void band_rotation(const CELTMode *m, float *X, int dir)
{
int i, B;
const int *eBands = m->eBands;
B = m->nbMdctBlocks*m->nbChannels;
for (i=0;i<m->nbEBands;i++)
{
float theta;
theta = pow(.1f,1.f*abs(m->nbPulses[i])/(B*(eBands[i+1]-eBands[i])));
exp_rotation(X+B*eBands[i], B*(eBands[i+1]-eBands[i]), theta, dir);
}
//printf ("\n");
}