ref: 3a4a463f0a1e17dad8adce1fa846743426e025c8
parent: 70bdf9bf39680d8ff808bd580cb2664db9d00f97
author: Jean-Marc Valin <[email protected]>
date: Mon Mar 15 18:55:51 EDT 2010
fixed-point: Further reduction in mismatch
--- a/libcelt/vq.c
+++ b/libcelt/vq.c
@@ -311,7 +311,6 @@
{int i;
celt_word32 E = EPSILON;
- celt_word16 rE;
celt_word16 g;
celt_norm *xptr = X;
for (i=0;i<N;i++)
@@ -319,21 +318,19 @@
E = MAC16_16(E, *xptr, *xptr);
xptr += stride;
}
-
- rE = celt_sqrt(E);
#ifdef FIXED_POINT
- if (rE <= 128)
- g = Q15ONE;
- else
+ int k = celt_ilog2(E)>>1;
#endif
- g = MULT16_16_Q15(value,celt_rcp(SHL32(rE,9)));
+ celt_word32 t = VSHR32(E, (k-7)<<1);
+ g = MULT16_16_Q15(value, celt_rsqrt_norm(t));
+
xptr = X;
for (i=0;i<N;i++)
{- *xptr = PSHR32(MULT16_16(g, *xptr),8);
+ *xptr = EXTRACT16(PSHR32(MULT16_16(g, *xptr), k+1));
xptr += stride;
}
- return rE;
+ return celt_sqrt(E);
}
static void fold(const CELTMode *m, int start, int N, const celt_norm * restrict Y, celt_norm * restrict P, int N0, int B)