1 | /******************************************************************** |
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2 | * * |
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3 | * THIS FILE IS PART OF THE OggVorbis SOFTWARE CODEC SOURCE CODE. * |
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4 | * USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS * |
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5 | * GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE * |
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6 | * IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING. * |
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7 | * * |
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8 | * THE OggVorbis SOURCE CODE IS (C) COPYRIGHT 1994-2007 * |
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9 | * by the Xiph.Org Foundation http://www.xiph.org/ * |
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10 | * * |
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11 | ******************************************************************** |
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12 | |
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13 | function: modified discrete cosine transform prototypes |
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14 | last mod: $Id: mdct.h 13293 2007-07-24 00:09:47Z xiphmont $ |
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15 | |
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16 | ********************************************************************/ |
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17 | |
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18 | #ifndef _OGG_mdct_H_ |
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19 | #define _OGG_mdct_H_ |
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20 | |
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21 | #include "vorbis/codec.h" |
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22 | |
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23 | |
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24 | |
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25 | |
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26 | |
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27 | /*#define MDCT_INTEGERIZED <- be warned there could be some hurt left here*/ |
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28 | #ifdef MDCT_INTEGERIZED |
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29 | |
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30 | #define DATA_TYPE int |
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31 | #define REG_TYPE register int |
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32 | #define TRIGBITS 14 |
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33 | #define cPI3_8 6270 |
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34 | #define cPI2_8 11585 |
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35 | #define cPI1_8 15137 |
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36 | |
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37 | #define FLOAT_CONV(x) ((int)((x)*(1<<TRIGBITS)+.5)) |
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38 | #define MULT_NORM(x) ((x)>>TRIGBITS) |
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39 | #define HALVE(x) ((x)>>1) |
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40 | |
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41 | #else |
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42 | |
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43 | #define DATA_TYPE float |
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44 | #define REG_TYPE float |
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45 | #define cPI3_8 .38268343236508977175F |
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46 | #define cPI2_8 .70710678118654752441F |
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47 | #define cPI1_8 .92387953251128675613F |
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48 | |
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49 | #define FLOAT_CONV(x) (x) |
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50 | #define MULT_NORM(x) (x) |
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51 | #define HALVE(x) ((x)*.5f) |
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52 | |
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53 | #endif |
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54 | |
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55 | |
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56 | typedef struct { |
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57 | int n; |
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58 | int log2n; |
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59 | |
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60 | DATA_TYPE *trig; |
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61 | int *bitrev; |
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62 | |
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63 | DATA_TYPE scale; |
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64 | } mdct_lookup; |
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65 | |
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66 | extern void mdct_init(mdct_lookup *lookup,int n); |
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67 | extern void mdct_clear(mdct_lookup *l); |
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68 | extern void mdct_forward(mdct_lookup *init, DATA_TYPE *in, DATA_TYPE *out); |
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69 | extern void mdct_backward(mdct_lookup *init, DATA_TYPE *in, DATA_TYPE *out); |
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70 | |
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71 | #endif |
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72 | |
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83 | |
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