ref: 1bc8a2e4b17c840e806856a7b7f44c4d118d4662
dir: /libcelt/vq.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.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "mathops.h"
#include "cwrs.h"
#include "vq.h"
#include "arch.h"
#include "os_support.h"
/** Takes the pitch vector and the decoded residual vector (non-compressed),
applies the compression in the pitch direction, computes the gain that will
give ||p+g*y||=1 and mixes the residual with the pitch. */
static void mix_pitch_and_residual(int *iy, celt_norm_t *X, int N, int K, const celt_norm_t *P)
{
int i;
celt_word32_t Ryp, Ryy, Rpp;
celt_word32_t g;
VARDECL(celt_norm_t, y);
#ifdef FIXED_POINT
int yshift;
#endif
SAVE_STACK;
#ifdef FIXED_POINT
yshift = 14-EC_ILOG(K);
#endif
ALLOC(y, N, celt_norm_t);
/*for (i=0;i<N;i++)
printf ("%d ", iy[i]);*/
Rpp = 0;
for (i=0;i<N;i++)
Rpp = MAC16_16(Rpp,P[i],P[i]);
Ryp = 0;
for (i=0;i<N;i++)
Ryp = MAC16_16(Ryp,SHL16(iy[i],yshift),P[i]);
/* Remove part of the pitch component to compute the real residual from
the encoded (int) one */
for (i=0;i<N;i++)
y[i] = SHL16(iy[i],yshift);
/* Recompute after the projection (I think it's right) */
Ryp = 0;
for (i=0;i<N;i++)
Ryp = MAC16_16(Ryp,y[i],P[i]);
Ryy = 0;
for (i=0;i<N;i++)
Ryy = MAC16_16(Ryy, y[i],y[i]);
/* g = (sqrt(Ryp^2 + Ryy - Rpp*Ryy)-Ryp)/Ryy */
g = MULT16_32_Q15(
celt_sqrt(MULT16_16(ROUND16(Ryp,14),ROUND16(Ryp,14)) + Ryy -
MULT16_16(ROUND16(Ryy,14),ROUND16(Rpp,14)))
- ROUND16(Ryp,14),
celt_rcp(SHR32(Ryy,9)));
for (i=0;i<N;i++)
X[i] = P[i] + ROUND16(MULT16_16(y[i], g),11);
RESTORE_STACK;
}
void alg_quant(celt_norm_t *X, celt_mask_t *W, int N, int K, const celt_norm_t *P, ec_enc *enc)
{
VARDECL(celt_norm_t, y);
VARDECL(int, iy);
VARDECL(int, signx);
VARDECL(celt_word32_t, scores);
int i, j, is;
celt_word16_t s;
int pulsesLeft;
celt_word32_t sum;
celt_word32_t xy, yy, yp;
celt_word16_t Rpp;
#ifdef FIXED_POINT
int yshift;
#endif
SAVE_STACK;
#ifdef FIXED_POINT
yshift = 14-EC_ILOG(K);
#endif
ALLOC(y, N, celt_norm_t);
ALLOC(iy, N, int);
ALLOC(signx, N, int);
ALLOC(scores, N, celt_word32_t);
for (j=0;j<N;j++)
{
if (X[j]>0)
signx[j]=1;
else
signx[j]=-1;
}
sum = 0;
for (j=0;j<N;j++)
{
sum = MAC16_16(sum, P[j],P[j]);
}
Rpp = ROUND16(sum, NORM_SHIFT);
celt_assert2(Rpp<=NORM_SCALING, "Rpp should never have a norm greater than unity");
for (i=0;i<N;i++)
y[i] = 0;
for (i=0;i<N;i++)
iy[i] = 0;
xy = yy = yp = 0;
pulsesLeft = K;
while (pulsesLeft > 0)
{
int pulsesAtOnce=1;
int sign;
celt_word32_t Rxy, Ryy, Ryp;
celt_word32_t g;
/* Decide on how many pulses to find at once */
pulsesAtOnce = pulsesLeft/N;
if (pulsesAtOnce<1)
pulsesAtOnce = 1;
/* Choose between fast and accurate strategy depending on where we are in the search */
if (pulsesLeft>1)
{
for (j=0;j<N;j++)
{
/* Select sign based on X[j] alone */
sign = signx[j];
s = SHL16(sign*pulsesAtOnce, yshift);
/* Temporary sums of the new pulse(s) */
Rxy = xy + MULT16_16(s,X[j]);
Ryy = yy + 2*MULT16_16(s,y[j]) + MULT16_16(s,s);
Ryp = yp + MULT16_16(s, P[j]);
scores[j] = MULT32_32_Q31(MULT16_16(ROUND16(Rxy,14),ABS16(ROUND16(Rxy,14))), celt_rcp(SHR32(Ryy,12)));
}
} else {
for (j=0;j<N;j++)
{
/* Select sign based on X[j] alone */
sign = signx[j];
s = SHL16(sign*pulsesAtOnce, yshift);
/* Temporary sums of the new pulse(s) */
Rxy = xy + MULT16_16(s,X[j]);
Ryy = yy + 2*MULT16_16(s,y[j]) + MULT16_16(s,s);
Ryp = yp + MULT16_16(s, P[j]);
/* Compute the gain such that ||p + g*y|| = 1 */
g = MULT16_32_Q15(
celt_sqrt(MULT16_16(ROUND16(Ryp,14),ROUND16(Ryp,14)) + Ryy -
MULT16_16(ROUND16(Ryy,14),Rpp))
- ROUND16(Ryp,14),
celt_rcp(SHR32(Ryy,12)));
/* Knowing that gain, what's the error: (x-g*y)^2
(result is negated and we discard x^2 because it's constant) */
/* score = 2.f*g*Rxy - 1.f*g*g*Ryy*NORM_SCALING_1;*/
scores[j] = 2*MULT16_32_Q14(ROUND16(Rxy,14),g)
- MULT16_32_Q14(EXTRACT16(MULT16_32_Q14(ROUND16(Ryy,14),g)),g);
}
}
j = find_max32(scores, N);
is = signx[j]*pulsesAtOnce;
s = SHL16(is, yshift);
/* Updating the sums of the new pulse(s) */
xy = xy + MULT16_16(s,X[j]);
yy = yy + 2*MULT16_16(s,y[j]) + MULT16_16(s,s);
yp = yp + MULT16_16(s, P[j]);
/* Only now that we've made the final choice, update y/iy */
y[j] += s;
iy[j] += is;
pulsesLeft -= pulsesAtOnce;
}
encode_pulses(iy, N, K, enc);
/* Recompute the gain in one pass to reduce the encoder-decoder mismatch
due to the recursive computation used in quantisation. */
mix_pitch_and_residual(iy, X, N, K, P);
RESTORE_STACK;
}
/** Decode pulse vector and combine the result with the pitch vector to produce
the final normalised signal in the current band. */
void alg_unquant(celt_norm_t *X, int N, int K, celt_norm_t *P, ec_dec *dec)
{
VARDECL(int, iy);
SAVE_STACK;
ALLOC(iy, N, int);
decode_pulses(iy, N, K, dec);
mix_pitch_and_residual(iy, X, N, K, P);
RESTORE_STACK;
}
#ifdef FIXED_POINT
static const celt_word16_t pg[11] = {32767, 24576, 21299, 19661, 19661, 19661, 18022, 18022, 16384, 16384, 16384};
#else
static const celt_word16_t pg[11] = {1.f, .75f, .65f, 0.6f, 0.6f, .6f, .55f, .55f, .5f, .5f, .5f};
#endif
#define MAX_INTRA 32
#define LOG_MAX_INTRA 5
void intra_prediction(celt_norm_t *x, celt_mask_t *W, int N, int K, celt_norm_t *Y, celt_norm_t *P, int B, int N0, ec_enc *enc)
{
int i,j;
int best=0;
celt_word32_t best_score=0;
celt_word16_t s = 1;
int sign;
celt_word32_t E;
celt_word16_t pred_gain;
int max_pos = N0-N/B;
if (max_pos > MAX_INTRA)
max_pos = MAX_INTRA;
for (i=0;i<max_pos*B;i+=B)
{
celt_word32_t xy=0, yy=0;
celt_word32_t score;
/* If this doesn't generate a double-MAC on supported architectures,
complain to your compilor vendor */
for (j=0;j<N;j++)
{
xy = MAC16_16(xy, x[j], Y[i+N-j-1]);
yy = MAC16_16(yy, Y[i+N-j-1], Y[i+N-j-1]);
}
/* If you're really desperate for speed, just use xy as the score */
score = celt_div(MULT16_16(ROUND16(xy,14),ROUND16(xy,14)), ROUND16(yy,14));
if (score > best_score)
{
best_score = score;
best = i;
/* Store xy as the sign. We'll normalise it to +/- 1 later. */
s = ROUND16(xy,14);
}
}
if (s<0)
{
s = -1;
sign = 1;
} else {
s = 1;
sign = 0;
}
/*printf ("%d %d ", sign, best);*/
ec_enc_bits(enc,sign,1);
if (max_pos == MAX_INTRA)
ec_enc_bits(enc,best/B,LOG_MAX_INTRA);
else
ec_enc_uint(enc,best/B,max_pos);
/*printf ("%d %f\n", best, best_score);*/
if (K>10)
pred_gain = pg[10];
else
pred_gain = pg[K];
E = EPSILON;
for (j=0;j<N;j++)
{
P[j] = s*Y[best+N-j-1];
E = MAC16_16(E, P[j],P[j]);
}
/*pred_gain = pred_gain/sqrt(E);*/
pred_gain = MULT16_16_Q15(pred_gain,celt_rcp(SHL32(celt_sqrt(E),9)));
for (j=0;j<N;j++)
P[j] = PSHR32(MULT16_16(pred_gain, P[j]),8);
if (K>0)
{
for (j=0;j<N;j++)
x[j] -= P[j];
} else {
for (j=0;j<N;j++)
x[j] = P[j];
}
/*printf ("quant ");*/
/*for (j=0;j<N;j++) printf ("%f ", P[j]);*/
}
void intra_unquant(celt_norm_t *x, int N, int K, celt_norm_t *Y, celt_norm_t *P, int B, int N0, ec_dec *dec)
{
int j;
int sign;
celt_word16_t s;
int best;
celt_word32_t E;
celt_word16_t pred_gain;
int max_pos = N0-N/B;
if (max_pos > MAX_INTRA)
max_pos = MAX_INTRA;
sign = ec_dec_bits(dec, 1);
if (sign == 0)
s = 1;
else
s = -1;
if (max_pos == MAX_INTRA)
best = B*ec_dec_bits(dec, LOG_MAX_INTRA);
else
best = B*ec_dec_uint(dec, max_pos);
/*printf ("%d %d ", sign, best);*/
if (K>10)
pred_gain = pg[10];
else
pred_gain = pg[K];
E = EPSILON;
for (j=0;j<N;j++)
{
P[j] = s*Y[best+N-j-1];
E = MAC16_16(E, P[j],P[j]);
}
/*pred_gain = pred_gain/sqrt(E);*/
pred_gain = MULT16_16_Q15(pred_gain,celt_rcp(SHL32(celt_sqrt(E),9)));
for (j=0;j<N;j++)
P[j] = PSHR32(MULT16_16(pred_gain, P[j]),8);
if (K==0)
{
for (j=0;j<N;j++)
x[j] = P[j];
}
}
void intra_fold(celt_norm_t *x, int N, celt_norm_t *Y, celt_norm_t *P, int B, int N0, int Nmax)
{
int i, j;
celt_word32_t E;
celt_word16_t g;
E = EPSILON;
if (N0 >= (Nmax>>1))
{
for (i=0;i<B;i++)
{
for (j=0;j<N/B;j++)
{
P[j*B+i] = Y[(Nmax-N0-j-1)*B+i];
E += P[j*B+i]*P[j*B+i];
}
}
} else {
for (j=0;j<N;j++)
{
P[j] = Y[j];
E = MAC16_16(E, P[j],P[j]);
}
}
g = celt_rcp(SHL32(celt_sqrt(E),9));
for (j=0;j<N;j++)
P[j] = PSHR32(MULT16_16(g, P[j]),8);
for (j=0;j<N;j++)
x[j] = P[j];
}