ref: 4c27552b090ad686d078a1006186865d7eb27947
parent: cae30df09ade8ea53b0722024d627c0a12fc7f1a
author: Jean-Marc Valin <[email protected]>
date: Fri May 21 03:54:59 EDT 2010
Tuning/cleanup of angle quantization
--- a/libcelt/bands.c
+++ b/libcelt/bands.c
@@ -454,11 +454,14 @@
int qalloc;
celt_word16 mid, side;
if (N>1)
- qb = (b-2*(N-1)*(QTHETA_OFFSET-m->logN[i]-(LM<<BITRES)))/(32*(N-1));
- else
- qb = b-2;
- if (qb > (b>>BITRES)-1)
- qb = (b>>BITRES)-1;
+ {+ qb = (b-2*(N-1)*(QTHETA_OFFSET-m->logN[i]-(LM<<BITRES)))/(2*(N-1)<<BITRES);
+ if (qb > (b>>(BITRES+1))-1)
+ qb = (b>>(BITRES+1))-1;
+ } else {+ /* For N==1, allocate two bits for the signs and the rest goes to qb */
+ qb = b-(2<<BITRES);
+ }
if (qb<0)
qb = 0;
if (qb>14)
@@ -480,15 +483,13 @@
#endif
}
- qalloc = log2_frac((1<<qb)+1,BITRES);
+ qalloc = 0;
if (qb==0)
{itheta=0;
} else {int shift;
- int fs=1, ft;
shift = 14-qb;
- ft = ((1<<qb>>1)+1)*((1<<qb>>1)+1);
/* Entropy coding of the angle. We use a uniform pdf for the
first stereo split but a triangular one for the rest. */
@@ -500,7 +501,10 @@
ec_enc_uint(ec, itheta, (1<<qb)+1);
else
itheta = ec_dec_uint((ec_dec*)ec, (1<<qb)+1);
+ qalloc = log2_frac((1<<qb)+1,BITRES);
} else {+ int fs=1, ft;
+ ft = ((1<<qb>>1)+1)*((1<<qb>>1)+1);
if (encode)
{int j;