release/src/router/libvorbis/lib/mdct.h

   1 /********************************************************************
   2  *                                                                  *
   3  * THIS FILE IS PART OF THE OggVorbis SOFTWARE CODEC SOURCE CODE.   *
   4  * USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS     *
   5  * GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *
   6  * IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING.       *
   7  *                                                                  *
   8  * THE OggVorbis SOURCE CODE IS (C) COPYRIGHT 1994-2009             *
   9  * by the Xiph.Org Foundation http://www.xiph.org/                  *
  10  *                                                                  *
  11  ********************************************************************
  12
  13  function: modified discrete cosine transform prototypes
  14  last mod: $Id: mdct.h 16227 2009-07-08 06:58:46Z xiphmont $
  15
  16  ********************************************************************/
  17
  18 #ifndef _OGG_mdct_H_
  19 #define _OGG_mdct_H_
  20
  21 #include "vorbis/codec.h"
  22
  23
  24
  25
  26
  27 /*#define MDCT_INTEGERIZED  <- be warned there could be some hurt left here*/
  28 #ifdef MDCT_INTEGERIZED
  29
  30 #define DATA_TYPE int
  31 #define REG_TYPE  register int
  32 #define TRIGBITS 14
  33 #define cPI3_8 6270
  34 #define cPI2_8 11585
  35 #define cPI1_8 15137
  36
  37 #define FLOAT_CONV(x) ((int)((x)*(1<<TRIGBITS)+.5))
  38 #define MULT_NORM(x) ((x)>>TRIGBITS)
  39 #define HALVE(x) ((x)>>1)
  40
  41 #else
  42
  43 #define DATA_TYPE float
  44 #define REG_TYPE  float
  45 #define cPI3_8 .38268343236508977175F
  46 #define cPI2_8 .70710678118654752441F
  47 #define cPI1_8 .92387953251128675613F
  48
  49 #define FLOAT_CONV(x) (x)
  50 #define MULT_NORM(x) (x)
  51 #define HALVE(x) ((x)*.5f)
  52
  53 #endif
  54
  55
  56 typedef struct {
  57   int n;
  58   int log2n;
  59
  60   DATA_TYPE *trig;
  61   int       *bitrev;
  62
  63   DATA_TYPE scale;
  64 } mdct_lookup;
  65
  66 extern void mdct_init(mdct_lookup *lookup,int n);
  67 extern void mdct_clear(mdct_lookup *l);
  68 extern void mdct_forward(mdct_lookup *init, DATA_TYPE *in, DATA_TYPE *out);
  69 extern void mdct_backward(mdct_lookup *init, DATA_TYPE *in, DATA_TYPE *out);
  70
  71 #endif