ref: c4711e4e11b0672e2b6466ae5df2209938d7aca3
parent: bbc010c4f3e63661442d35af8877ff5a5cce3903
author: Jean-Marc Valin <[email protected]>
date: Fri Oct 15 19:31:06 EDT 2010
More VQ search simplifications
--- a/libcelt/vq.c
+++ b/libcelt/vq.c
@@ -171,8 +171,8 @@
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 @@
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);
@@ -290,21 +289,18 @@
#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) */
Rxy = MULT16_16_Q15(Rxy,Rxy);
@@ -319,17 +315,15 @@
}
} 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 */