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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
Download patch file Download diff file Expand all files Collapse all files

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");
}

2
libcelt/bands.h
View file

@ -51,4 +51,6 @@ void quant_bands(const CELTMode *m, float *X, float *P, ec_enc *enc);
void unquant_bands(const CELTMode *m, float *X, float *P, ec_dec *dec);
void band_rotation(const CELTMode *m, float *X, int dir);
#endif /* BANDS_H */

8
libcelt/celt.c
View file

@ -266,6 +266,9 @@ int celt_encode(CELTEncoder *st, short *pcm)
normalise_bands(st->mode, P, bandEp);
}
band_rotation(st->mode, X, -1);
band_rotation(st->mode, P, -1);
quant_energy(st->mode, bandE, st->oldBandE, &st->enc);
/* Pitch prediction */
@ -295,6 +298,8 @@ int celt_encode(CELTEncoder *st, short *pcm)
//printf ("\n");
}
band_rotation(st->mode, X, 1);
/* Synthesis */
denormalise_bands(st->mode, X, bandE);
@ -495,6 +500,7 @@ int celt_decode(CELTDecoder *st, char *data, int len, short *pcm)
compute_band_energies(st->mode, P, bandEp);
normalise_bands(st->mode, P, bandEp);
}
band_rotation(st->mode, P, -1);
/* Get the pitch gains */
unquant_pitch(gains, st->mode->nbPBands, &dec);
@ -505,6 +511,8 @@ int celt_decode(CELTDecoder *st, char *data, int len, short *pcm)
/* Decode fixed codebook and merge with pitch */
unquant_bands(st->mode, X, P, &dec);
band_rotation(st->mode, X, 1);
/* Synthesis */
denormalise_bands(st->mode, X, bandE);

6
libcelt/modes.c
View file

@ -39,7 +39,7 @@ const int qbank1[NBANDS128+2] = {0, 2, 4, 6, 8, 12, 16, 20, 24, 28, 36, 44, 52
const int qpulses1[NBANDS128] = {7, 5, 5, 5, 4, 5, 4, 5, 5, 4, -2, 0, 0, 0, 0};
const int qpulses2[NBANDS128] = {28,24,20,16,24,20, 18, 12, 10, 10,-7, -4, 0, 0, 0};
const int qpulses2b[NBANDS128] = {32,28,24,20,28,24, 22, 18, 16, 15,-12, -12, 12, 12, 0};
const int qpulses2s[NBANDS128] = {38,30,24,20,24,20, 18, 16, 14, 20,-20,-14, -8, -8, -5};
const int pbank1[PBANDS128+2] = {0, 4, 8, 12, 20, PITCH_END128, 128};
@ -94,7 +94,7 @@ const CELTMode mode3 = {
qpulses2 /**< nbPulses */
};
/* Stereo mode (doesn't work yet) */
/* Stereo mode around 120 kbps */
const CELTMode mode4 = {
256, /**< frameSize */
128, /**< mdctSize */
@ -107,7 +107,7 @@ const CELTMode mode4 = {
qbank1, /**< eBands */
pbank1, /**< pBands*/
qpulses1 /**< nbPulses */
qpulses2s /**< nbPulses */
};
const CELTMode const *celt_mode1 = &mode1;

45
libcelt/vq.c
View file

@ -38,9 +38,9 @@
/* Improved algebraic pulse-base quantiser. The signal x is replaced by the sum of the pitch
a combination of pulses such that its norm is still equal to 1. The only difference with
the quantiser above is that the search is more complete. */
void alg_quant(float *x, int N, int K, float *p, ec_enc *enc)
void alg_quant(float *x, int N, int K, float *p, float alpha, ec_enc *enc)
{
int L = 5;
int L = 3;
//float tata[200];
float y[L][N];
int iy[L][N];
@ -55,7 +55,6 @@ void alg_quant(float *x, int N, int K, float *p, ec_enc *enc)
float Rpp=0, Rxp=0;
float gain[L];
int maxL = 1;
float alpha = .9;
for (j=0;j<N;j++)
Rpp += p[j]*p[j];
@ -188,9 +187,40 @@ void alg_quant(float *x, int N, int K, float *p, ec_enc *enc)
// printf ("%d ", iy[0][i]);
pulse2comb(N, K, comb, signs, iy[0]);
ec_enc_uint64(enc,icwrs64(N, K, comb, signs),ncwrs64(N, K));
/* Recompute the gain in one pass (to reduce errors) */
if (0) {
float Ryp=0;
float Rpp=0;
float Ryy=0;
float g=0;
for (i=0;i<N;i++)
Rpp += p[i]*p[i];
for (i=0;i<N;i++)
Ryp += iy[0][i]*p[i];
for (i=0;i<N;i++)
y[0][i] = iy[0][i] - alpha*Ryp*p[i];
/* Recompute after the projection (I think it's right) */
Ryp = 0;
for (i=0;i<N;i++)
Ryp += y[0][i]*p[i];
for (i=0;i<N;i++)
Ryy += y[0][i]*y[0][i];
g = (sqrt(Ryp*Ryp + Ryy - Ryy*Rpp) - Ryp)/Ryy;
for (i=0;i<N;i++)
x[i] = p[i] + g*y[0][i];
}
static const float pg[5] = {1.f, .82f, .75f, 0.7f, 0.6f};
}
static const float pg[5] = {1.f, .6f, .45f, 0.35f, 0.25f};
/* Finds the right offset into Y and copy it */
void copy_quant(float *x, int N, int K, float *Y, int B, int N0, ec_enc *enc)
@ -257,11 +287,11 @@ void copy_quant(float *x, int N, int K, float *Y, int B, int N0, ec_enc *enc)
E = .8/sqrt(E);
for (j=0;j<N;j++)
P[j] *= E;
alg_quant(x, N, K, P, enc);
alg_quant(x, N, K, P, 0, enc);
}
}
void alg_unquant(float *x, int N, int K, float *p, ec_dec *dec)
void alg_unquant(float *x, int N, int K, float *p, float alpha, ec_dec *dec)
{
int i;
celt_uint64_t id;
@ -269,7 +299,6 @@ void alg_unquant(float *x, int N, int K, float *p, ec_dec *dec)
int signs[K];
int iy[N];
float y[N];
float alpha = .9;
float Rpp=0, Ryp=0, Ryy=0;
float g;
@ -344,6 +373,6 @@ void copy_unquant(float *x, int N, int K, float *Y, int B, int N0, ec_dec *dec)
E = .8/sqrt(E);
for (j=0;j<N;j++)
P[j] *= E;
alg_unquant(x, N, K, P, dec);
alg_unquant(x, N, K, P, 0, dec);
}
}

4
libcelt/vq.h
View file

@ -39,9 +39,9 @@
/* Algebraic pulse-base quantiser. The signal x is replaced by the sum of the pitch
a combination of pulses such that its norm is still equal to 1. The only difference with
the quantiser above is that the search is more complete. */
void alg_quant(float *x, int N, int K, float *p, ec_enc *enc);
void alg_quant(float *x, int N, int K, float *p, float alpha, ec_enc *enc);
void alg_unquant(float *x, int N, int K, float *p, ec_dec *dec);
void alg_unquant(float *x, int N, int K, float *p, float alpha, ec_dec *dec);
/* Finds the right offset into Y and copy it */
void copy_quant(float *x, int N, int K, float *Y, int B, int N0, ec_enc *enc);