/********************************************************************
* *
* THIS FILE IS PART OF THE OggVorbis SOFTWARE CODEC SOURCE CODE. *
- * USE, DISTRIBUTION AND REPRODUCTION OF THIS SOURCE IS GOVERNED BY *
- * THE GNU LESSER/LIBRARY PUBLIC LICENSE, WHICH IS INCLUDED WITH *
- * THIS SOURCE. PLEASE READ THESE TERMS BEFORE DISTRIBUTING. *
+ * USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS *
+ * 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 1994-2000 *
- * by Monty <monty@xiph.org> and the XIPHOPHORUS Company *
- * http://www.xiph.org/ *
+ * THE OggVorbis SOURCE CODE IS (C) COPYRIGHT 1994-2009 *
+ * by the Xiph.Org Foundation https://xiph.org/ *
* *
********************************************************************
function: lookup based functions
- last mod: $Id: lookup.c,v 1.4 2000/12/21 21:04:39 xiphmont Exp $
********************************************************************/
#include "lookup.h"
#include "lookup_data.h"
#include "os.h"
+#include "misc.h"
#ifdef FLOAT_LOOKUP
#include <stdio.h>
/* interpolated lookup based fromdB function, domain -140dB to 0dB only */
float vorbis_fromdBlook(float a){
- int i=vorbis_ftoi(a*((float)(-(1<<FROMdB2_SHIFT)))-5.f);
+ int i=vorbis_ftoi(a*((float)(-(1<<FROMdB2_SHIFT)))-.5f);
return (i<0)?1.f:
((i>=(FROMdB_LOOKUP_SZ<<FROMdB_SHIFT))?0.f:
FROMdB_LOOKUP[i>>FROMdB_SHIFT]*FROMdB2_LOOKUP[i&FROMdB2_MASK]);
#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