ref: 134492afd3efee0f4259ff4a00c4c6a101ed1f8d
dir: /libcelt/quant_bands.c/
/* (C) 2007 Jean-Marc Valin, CSIRO
*/
/*
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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
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*/
#include "quant_bands.h"
#include "laplace.h"
#include <math.h>
#include "os_support.h"
const float eMeans[24] = {45.f, -8.f, -12.f, -2.5f, 1.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f};
//const int frac[24] = {4, 3, 3, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2};
const int frac[24] = {8, 6, 5, 4, 3, 3, 3, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2};
static void quant_energy_mono(const CELTMode *m, float *eBands, float *oldEBands, int budget, ec_enc *enc)
{
int i;
int bits;
float prev = 0;
float coef = m->ePredCoef;
float error[m->nbEBands];
/* The .7 is a heuristic */
float beta = .7*coef;
bits = ec_enc_tell(enc, 0);
for (i=0;i<m->nbEBands;i++)
{
int qi;
float q;
float res;
float x;
float f;
float mean = (1-coef)*eMeans[i];
x = 20*log10(.3+eBands[i]);
res = 6.;
//res = 1;
f = (x-mean-coef*oldEBands[i]-prev)/res;
qi = (int)floor(.5+f);
//if (i> 4 && qi<-2)
// qi = -2;
//ec_laplace_encode(enc, qi, i==0?11192:6192);
//ec_laplace_encode(enc, qi, 8500-i*200);
/* If we don't have enough bits to encode all the energy, just assume something safe. */
if (ec_enc_tell(enc, 0) - bits > budget)
qi = -1;
else
ec_laplace_encode(enc, qi, 6000-i*200);
q = qi*res;
error[i] = f - qi;
//printf("%d ", qi);
//printf("%f %f ", pred+prev+q, x);
//printf("%f ", x-pred);
oldEBands[i] = mean+coef*oldEBands[i]+prev+q;
prev = mean+prev+(1-beta)*q;
}
//bits = ec_enc_tell(enc, 0) - bits;
//printf ("%d\n", bits);
for (i=0;i<m->nbEBands;i++)
{
int q2;
float offset = (error[i]+.5)*frac[i];
/* FIXME: Instead of giving up without warning, we should degrade everything gracefully */
if (ec_enc_tell(enc, 0) - bits +ec_ilog(frac[i])> budget)
break;
q2 = (int)floor(offset);
if (q2 > frac[i]-1)
q2 = frac[i]-1;
ec_enc_uint(enc, q2, frac[i]);
offset = ((q2+.5)/frac[i])-.5;
oldEBands[i] += 6.*offset;
//printf ("%f ", error[i] - offset);
}
for (i=0;i<m->nbEBands;i++)
{
eBands[i] = pow(10, .05*oldEBands[i])-.3;
if (eBands[i] < 0)
eBands[i] = 0;
}
//printf ("%d\n", ec_enc_tell(enc, 0)-9);
//printf ("\n");
}
static void unquant_energy_mono(const CELTMode *m, float *eBands, float *oldEBands, int budget, ec_dec *dec)
{
int i;
int bits;
float prev = 0;
float coef = m->ePredCoef;
/* The .7 is a heuristic */
float beta = .7*coef;
bits = ec_dec_tell(dec, 0);
for (i=0;i<m->nbEBands;i++)
{
int qi;
float q;
float res;
float mean = (1-coef)*eMeans[i];
res = 6.;
/* If we didn't have enough bits to encode all the energy, just assume something safe. */
if (ec_dec_tell(dec, 0) - bits > budget)
qi = -1;
else
qi = ec_laplace_decode(dec, 6000-i*200);
q = qi*res;
oldEBands[i] = mean+coef*oldEBands[i]+prev+q;
prev = mean+prev+(1-beta)*q;
}
for (i=0;i<m->nbEBands;i++)
{
int q2;
float offset;
if (ec_dec_tell(dec, 0) - bits +ec_ilog(frac[i])> budget)
break;
q2 = ec_dec_uint(dec, frac[i]);
offset = ((q2+.5)/frac[i])-.5;
oldEBands[i] += 6.*offset;
}
for (i=0;i<m->nbEBands;i++)
{
//printf ("%f ", error[i] - offset);
eBands[i] = pow(10, .05*oldEBands[i])-.3;
if (eBands[i] < 0)
eBands[i] = 0;
}
//printf ("\n");
}
void quant_energy(const CELTMode *m, float *eBands, float *oldEBands, int budget, ec_enc *enc)
{
int C;
C = m->nbChannels;
if (C==1)
quant_energy_mono(m, eBands, oldEBands, budget, enc);
else
#if 1
{
int c;
for (c=0;c<C;c++)
{
int i;
float E[m->nbEBands];
for (i=0;i<m->nbEBands;i++)
E[i] = eBands[C*i+c];
quant_energy_mono(m, E, oldEBands+c*m->nbEBands, budget/C, enc);
for (i=0;i<m->nbEBands;i++)
eBands[C*i+c] = E[i];
}
}
#else
if (C==2)
{
int i;
int NB = m->nbEBands;
float mid[NB];
float side[NB];
float left;
float right;
for (i=0;i<NB;i++)
{
//left = eBands[C*i];
//right = eBands[C*i+1];
mid[i] = sqrt(eBands[C*i]*eBands[C*i] + eBands[C*i+1]*eBands[C*i+1]);
side[i] = 20*log10((eBands[2*i]+.3)/(eBands[2*i+1]+.3));
//printf ("%f %f ", mid[i], side[i]);
}
//printf ("\n");
quant_energy_mono(m, mid, oldEBands, enc);
for (i=0;i<NB;i++)
side[i] = pow(10.f,floor(.5f+side[i])/10.f);
//quant_energy_side(m, side, oldEBands+NB, enc);
for (i=0;i<NB;i++)
{
eBands[C*i] = mid[i]*sqrt(side[i]/(1.f+side[i]));
eBands[C*i+1] = mid[i]*sqrt(1.f/(1.f+side[i]));
//printf ("%f %f ", mid[i], side[i]);
}
} else {
celt_fatal("more than 2 channels not supported");
}
#endif
}
void unquant_energy(const CELTMode *m, float *eBands, float *oldEBands, int budget, ec_dec *dec)
{
int C;
C = m->nbChannels;
if (C==1)
unquant_energy_mono(m, eBands, oldEBands, budget, dec);
else {
int c;
for (c=0;c<C;c++)
{
int i;
float E[m->nbEBands];
unquant_energy_mono(m, E, oldEBands+c*m->nbEBands, budget/C, dec);
for (i=0;i<m->nbEBands;i++)
eBands[C*i+c] = E[i];
}
}
}