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More flexible energy quantisation with nearly no penalty.

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This commit is contained in:
Jean-Marc Valin 2008-02-11 10:53:11 +11:00
parent c35883d74b
commit 66fa639c53
1 changed files with 75 additions and 33 deletions
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108
libcelt/quant_bands.c
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@ -35,38 +35,106 @@
#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] = {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, ec_enc *enc)
{
int i;
float prev = 0;
float coef = m->ePredCoef;
float error[m->nbEBands];
/* The .7 is a heuristic */
float beta = .7*coef;
for (i=0;i<m->nbEBands;i++)
{
int qi;
float q;
float res;
float x;
float pred = m->ePredCoef*oldEBands[i]+m->eMeans[i];
float f;
float mean = (1-coef)*eMeans[i];
x = 20*log10(.3+eBands[i]);
res = .25f*(i+3.f);
res = 6.;
//res = 1;
qi = (int)floor(.5+(x-pred-prev)/res);
ec_laplace_encode(enc, qi, m->eDecay[i]);
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);
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] = pred+prev+q;
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 = (error[i]+.5)*frac[i];
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);
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, ec_dec *dec)
{
int i;
float prev = 0;
float coef = m->ePredCoef;
float error[m->nbEBands];
/* The .7 is a heuristic */
float beta = .7*coef;
for (i=0;i<m->nbEBands;i++)
{
int qi;
float q;
float res;
float mean = (1-coef)*eMeans[i];
res = 6.;
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;
q2 = ec_dec_uint(dec, frac[i]);
offset = ((q2+.5)/frac[i])-.5;
oldEBands[i] += 6.*offset;
//printf ("%f ", error[i] - offset);
eBands[i] = pow(10, .05*oldEBands[i])-.3;
if (eBands[i] < 0)
eBands[i] = 0;
prev = (prev + .5*q);
}
//printf ("\n");
}
void quant_energy(const CELTMode *m, float *eBands, float *oldEBands, ec_enc *enc)
{
int C;
@ -127,32 +195,6 @@ void quant_energy(const CELTMode *m, float *eBands, float *oldEBands, ec_enc *en
}
static void unquant_energy_mono(const CELTMode *m, float *eBands, float *oldEBands, ec_dec *dec)
{
int i;
float prev = 0;
for (i=0;i<m->nbEBands;i++)
{
int qi;
float q;
float res;
float pred = m->ePredCoef*oldEBands[i]+m->eMeans[i];
res = .25f*(i+3.f);
qi = ec_laplace_decode(dec, m->eDecay[i]);
q = qi*res;
//printf("%f %f ", pred+prev+q, x);
//printf("%d ", qi);
//printf("%f ", x-pred-prev);
oldEBands[i] = pred+prev+q;
eBands[i] = pow(10, .05*oldEBands[i])-.3;
if (eBands[i] < 0)
eBands[i] = 0;
prev = (prev + .5*q);
}
//printf ("\n");
}
void unquant_energy(const CELTMode *m, float *eBands, float *oldEBands, ec_dec *dec)
{