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Working on some stability issues (appears to be solved by making the pitch

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projection less aggressive). Also, fixed a 64-bit overflow in the stereo mode
and added a "band rotation" function.
This commit is contained in:
Jean-Marc Valin 2007-12-12 00:45:15 +11:00
parent f347dd3b3d
commit 4a897680e3
6 changed files with 140 additions and 17 deletions
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92
libcelt/bands.c
View file

@ -35,6 +35,74 @@
#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)
@ -159,16 +227,18 @@ void quant_bands(const CELTMode *m, float *X, float *P, ec_enc *enc)
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], enc);
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(ncwrs(B*(eBands[i+1]-eBands[i]), q))/(B*(eBands[i+1]-eBands[i])));
//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(ncwrs(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)))/(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");
@ -189,7 +259,7 @@ void unquant_bands(const CELTMode *m, float *X, float *P, ec_dec *dec)
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], dec);
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 {
@ -204,3 +274,17 @@ void unquant_bands(const CELTMode *m, float *X, float *P, ec_dec *dec)
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");
}