* GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *
* IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING. *
* *
- * THE OggVorbis SOURCE CODE IS (C) COPYRIGHT 1994-2002 *
- * by the XIPHOPHORUS Company http://www.xiph.org/ *
+ * THE OggVorbis SOURCE CODE IS (C) COPYRIGHT 1994-2009 *
+ * by the Xiph.Org Foundation http://www.xiph.org/ *
* *
********************************************************************
function: lookup based functions
- last mod: $Id: lookup.c,v 1.9 2002/01/22 08:06:07 xiphmont Exp $
********************************************************************/
#ifdef INT_LOOKUP
/* interpolated 1./sqrt(p) where .5 <= a < 1. (.100000... to .111111...) in
- 16.16 format
+ 16.16 format
returns in m.8 format */
long vorbis_invsqlook_i(long a,long e){
- long i=(a&0x7fff)>>(INVSQ_LOOKUP_I_SHIFT-1);
+ long i=(a&0x7fff)>>(INVSQ_LOOKUP_I_SHIFT-1);
long d=(a&INVSQ_LOOKUP_I_MASK)<<(16-INVSQ_LOOKUP_I_SHIFT); /* 0.16 */
long val=INVSQ_LOOKUP_I[i]- /* 1.16 */
(((INVSQ_LOOKUP_I[i]-INVSQ_LOOKUP_I[i+1])* /* 0.16 */
d)>>16); /* result 1.16 */
-
+
e+=32;
if(e&1)val=(val*5792)>>13; /* multiply val by 1/sqrt(2) */
e=(e>>1)-8;
int i=a>>COS_LOOKUP_I_SHIFT;
int d=a&COS_LOOKUP_I_MASK;
return COS_LOOKUP_I[i]- ((d*(COS_LOOKUP_I[i]-COS_LOOKUP_I[i+1]))>>
- COS_LOOKUP_I_SHIFT);
+ COS_LOOKUP_I_SHIFT);
}
#endif