eden-emu/opus
19
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

More VQ search simplifications

Browse source
This commit is contained in:
Jean-Marc Valin 2010-10-15 23:31:06 -04:00
parent bbc010c4f3
commit c4711e4e11
1 changed files with 10 additions and 16 deletions
Download patch file Download diff file Expand all files Collapse all files

24
libcelt/vq.c
View file

@ -171,8 +171,8 @@ void alg_quant(celt_norm *X, int N, int K, int spread, int B, celt_norm *lowband
celt_word16 s;
int pulsesLeft;
celt_word32 sum;
celt_word32 xy, yy;
int N_1; /* Inverse of N, in Q14 format (even for float) */
celt_word32 xy;
celt_word16 yy;
SAVE_STACK;
/* When there's no pulse, fill with noise or folded spectrum */
@ -204,7 +204,6 @@ void alg_quant(celt_norm *X, int N, int K, int spread, int B, celt_norm *lowband
ALLOC(y, N, celt_norm);
ALLOC(iy, N, int);
ALLOC(signx, N, celt_word16);
N_1 = 512/N;
exp_rotation(X, N, 1, B, K, spread);
@ -290,20 +289,17 @@ void alg_quant(celt_norm *X, int N, int K, int spread, int B, celt_norm *lowband
#ifdef FIXED_POINT
rshift = 1+celt_ilog2(K-pulsesLeft+i+1);
#endif
best_id = 0;
/* The squared magnitude term gets added anyway, so we might as well
add it outside the loop */
yy = MAC16_16(yy, s,s);
/* Choose between fast and accurate strategy depending on where we are in the search */
/* This should ensure that anything we can process will have a better score */
yy = ADD32(yy, 1);
j=0;
do {
celt_word16 Rxy, Ryy;
/* Temporary sums of the new pulse(s) */
Rxy = EXTRACT16(SHR32(MAC16_16(xy, s,X[j]),rshift));
Rxy = EXTRACT16(SHR32(ADD32(xy, EXTEND32(X[j])),rshift));
/* We're multiplying y[j] by two so we don't have to do it here */
Ryy = MAC16_16(yy, s,y[j]);
Ryy = ADD16(yy, y[j]);
/* Approximate score: we maximise Rxy/sqrt(Ryy) (we're guaranteed that
Rxy is positive because the sign is pre-computed) */
@ -319,17 +315,15 @@ void alg_quant(celt_norm *X, int N, int K, int spread, int B, celt_norm *lowband
}
} while (++j<N);
j = best_id;
/* Updating the sums of the new pulse(s) */
xy = xy + MULT16_16(s,X[j]);
xy = ADD32(xy, EXTEND32(X[best_id]));
/* We're multiplying y[j] by two so we don't have to do it here */
yy = yy + MULT16_16(s,y[j]);
yy = ADD16(yy, y[best_id]);
/* Only now that we've made the final choice, update y/iy */
/* Multiplying y[j] by 2 so we don't have to do it everywhere else */
y[j] += 2*s;
iy[j]++;
y[best_id] += 2*s;
iy[best_id]++;
}
/* Put the original sign back */