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