diff options
author | hairball <xhairball@gmail.com> | 2014-02-08 08:26:03 +0000 |
---|---|---|
committer | Tim Angus <tim@ngus.net> | 2014-06-17 17:43:39 +0100 |
commit | 62d2323b93713ec9605163c30e2663e35ce9904f (patch) | |
tree | 005cfc8b1bd334b6dfc5330fefba8ba60bc152eb /src/libvorbis-1.3.4/lib/lookup.c | |
parent | 4e2fbffaf61a5784d0e449916b63d0a9b5d493a3 (diff) |
Add vorbis 1.3.4 build support
Diffstat (limited to 'src/libvorbis-1.3.4/lib/lookup.c')
-rw-r--r-- | src/libvorbis-1.3.4/lib/lookup.c | 94 |
1 files changed, 94 insertions, 0 deletions
diff --git a/src/libvorbis-1.3.4/lib/lookup.c b/src/libvorbis-1.3.4/lib/lookup.c new file mode 100644 index 00000000..3321ed3d --- /dev/null +++ b/src/libvorbis-1.3.4/lib/lookup.c @@ -0,0 +1,94 @@ +/******************************************************************** + * * + * THIS FILE IS PART OF THE OggVorbis SOFTWARE CODEC SOURCE CODE. * + * 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 1994-2009 * + * by the Xiph.Org Foundation http://www.xiph.org/ * + * * + ******************************************************************** + + function: lookup based functions + last mod: $Id: lookup.c 16227 2009-07-08 06:58:46Z xiphmont $ + + ********************************************************************/ + +#include <math.h> +#include "lookup.h" +#include "lookup_data.h" +#include "os.h" +#include "misc.h" + +#ifdef FLOAT_LOOKUP + +/* interpolated lookup based cos function, domain 0 to PI only */ +float vorbis_coslook(float a){ + double d=a*(.31830989*(float)COS_LOOKUP_SZ); + int i=vorbis_ftoi(d-.5); + + return COS_LOOKUP[i]+ (d-i)*(COS_LOOKUP[i+1]-COS_LOOKUP[i]); +} + +/* interpolated 1./sqrt(p) where .5 <= p < 1. */ +float vorbis_invsqlook(float a){ + double d=a*(2.f*(float)INVSQ_LOOKUP_SZ)-(float)INVSQ_LOOKUP_SZ; + int i=vorbis_ftoi(d-.5f); + return INVSQ_LOOKUP[i]+ (d-i)*(INVSQ_LOOKUP[i+1]-INVSQ_LOOKUP[i]); +} + +/* interpolated 1./sqrt(p) where .5 <= p < 1. */ +float vorbis_invsq2explook(int a){ + return INVSQ2EXP_LOOKUP[a-INVSQ2EXP_LOOKUP_MIN]; +} + +#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)))-.5f); + return (i<0)?1.f: + ((i>=(FROMdB_LOOKUP_SZ<<FROMdB_SHIFT))?0.f: + FROMdB_LOOKUP[i>>FROMdB_SHIFT]*FROMdB2_LOOKUP[i&FROMdB2_MASK]); +} + +#endif + +#ifdef INT_LOOKUP +/* interpolated 1./sqrt(p) where .5 <= a < 1. (.100000... to .111111...) in + 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 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; + + return(val>>e); +} + +/* interpolated lookup based fromdB function, domain -140dB to 0dB only */ +/* a is in n.12 format */ +float vorbis_fromdBlook_i(long a){ + int i=(-a)>>(12-FROMdB2_SHIFT); + return (i<0)?1.f: + ((i>=(FROMdB_LOOKUP_SZ<<FROMdB_SHIFT))?0.f: + FROMdB_LOOKUP[i>>FROMdB_SHIFT]*FROMdB2_LOOKUP[i&FROMdB2_MASK]); +} + +/* interpolated lookup based cos function, domain 0 to PI only */ +/* a is in 0.16 format, where 0==0, 2^^16-1==PI, return 0.14 */ +long vorbis_coslook_i(long a){ + 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); +} + +#endif |