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| Rev | Author | Line No. | Line |
|---|---|---|---|
| 2 | pj | 1 | |
| 2 | #include "mpg123.h" |
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| 3 | |||
| 4 | real decwin[512+32]; |
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| 5 | static real cos64[16],cos32[8],cos16[4],cos8[2],cos4[1]; |
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| 6 | real *pnts[] = { cos64,cos32,cos16,cos8,cos4 }; |
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| 7 | |||
| 8 | static unsigned char conv16to8_buf[4096]; |
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| 9 | unsigned char *conv16to8 = conv16to8_buf + 2048; |
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| 10 | |||
| 11 | static long intwinbase[] = { |
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| 12 | 0, -1, -1, -1, -1, -1, -1, -2, -2, -2, |
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| 13 | -2, -3, -3, -4, -4, -5, -5, -6, -7, -7, |
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| 14 | -8, -9, -10, -11, -13, -14, -16, -17, -19, -21, |
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| 15 | -24, -26, -29, -31, -35, -38, -41, -45, -49, -53, |
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| 16 | -58, -63, -68, -73, -79, -85, -91, -97, -104, -111, |
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| 17 | -117, -125, -132, -139, -147, -154, -161, -169, -176, -183, |
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| 18 | -190, -196, -202, -208, -213, -218, -222, -225, -227, -228, |
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| 19 | -228, -227, -224, -221, -215, -208, -200, -189, -177, -163, |
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| 20 | -146, -127, -106, -83, -57, -29, 2, 36, 72, 111, |
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| 21 | 153, 197, 244, 294, 347, 401, 459, 519, 581, 645, |
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| 22 | 711, 779, 848, 919, 991, 1064, 1137, 1210, 1283, 1356, |
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| 23 | 1428, 1498, 1567, 1634, 1698, 1759, 1817, 1870, 1919, 1962, |
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| 24 | 2001, 2032, 2057, 2075, 2085, 2087, 2080, 2063, 2037, 2000, |
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| 25 | 1952, 1893, 1822, 1739, 1644, 1535, 1414, 1280, 1131, 970, |
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| 26 | 794, 605, 402, 185, -45, -288, -545, -814, -1095, -1388, |
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| 27 | -1692, -2006, -2330, -2663, -3004, -3351, -3705, -4063, -4425, -4788, |
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| 28 | -5153, -5517, -5879, -6237, -6589, -6935, -7271, -7597, -7910, -8209, |
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| 29 | -8491, -8755, -8998, -9219, -9416, -9585, -9727, -9838, -9916, -9959, |
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| 30 | -9966, -9935, -9863, -9750, -9592, -9389, -9139, -8840, -8492, -8092, |
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| 31 | -7640, -7134, -6574, -5959, -5288, -4561, -3776, -2935, -2037, -1082, |
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| 32 | -70, 998, 2122, 3300, 4533, 5818, 7154, 8540, 9975, 11455, |
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| 33 | 12980, 14548, 16155, 17799, 19478, 21189, 22929, 24694, 26482, 28289, |
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| 34 | 30112, 31947, 33791, 35640, 37489, 39336, 41176, 43006, 44821, 46617, |
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| 35 | 48390, 50137, 51853, 53534, 55178, 56778, 58333, 59838, 61289, 62684, |
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| 36 | 64019, 65290, 66494, 67629, 68692, 69679, 70590, 71420, 72169, 72835, |
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| 37 | 73415, 73908, 74313, 74630, 74856, 74992, 75038 }; |
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| 38 | |||
| 39 | void make_decode_tables(long scaleval) |
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| 40 | { |
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| 41 | int i,j,k,kr,divv; |
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| 42 | real *table,*costab; |
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| 43 | |||
| 44 | for(i=0;i<5;i++) |
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| 45 | { |
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| 46 | kr=0x10>>i; divv=0x40>>i; |
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| 47 | costab = pnts[i]; |
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| 48 | for(k=0;k<kr;k++) |
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| 49 | costab[k] = 1.0 / (2.0 * cos(M_PI * ((double) k * 2.0 + 1.0) / (double) divv)); |
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| 50 | } |
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| 51 | |||
| 52 | table = decwin; |
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| 53 | scaleval = -scaleval; |
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| 54 | for(i=0,j=0;i<256;i++,j++,table+=32) |
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| 55 | { |
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| 56 | if(table < decwin+512+16) |
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| 57 | table[16] = table[0] = (double) intwinbase[j] / 65536.0 * (double) scaleval; |
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| 58 | if(i % 32 == 31) |
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| 59 | table -= 1023; |
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| 60 | if(i % 64 == 63) |
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| 61 | scaleval = - scaleval; |
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| 62 | } |
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| 63 | |||
| 64 | for( /* i=256 */ ;i<512;i++,j--,table+=32) |
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| 65 | { |
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| 66 | if(table < decwin+512+16) |
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| 67 | table[16] = table[0] = (double) intwinbase[j] / 65536.0 * (double) scaleval; |
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| 68 | if(i % 32 == 31) |
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| 69 | table -= 1023; |
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| 70 | if(i % 64 == 63) |
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| 71 | scaleval = - scaleval; |
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| 72 | } |
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| 73 | } |
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| 74 | |||
| 75 | void make_conv16to8_table(int mode) |
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| 76 | { |
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| 77 | int i; |
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| 78 | unsigned char c; |
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| 79 | if(mode == AUDIO_FORMAT_ULAW_8) { |
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| 80 | double m=127.0 / log(256.0); |
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| 81 | for(i=-2048;i<2048;i++) { |
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| 82 | /* dunno whether this is a valid transformation rule ?!?!? */ |
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| 83 | if(i < 0) |
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| 84 | c = 127 - (int) (log( 1.0 - 255.0 * (double) i*16.0 / 32767.0 ) * m); |
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| 85 | else |
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| 86 | c = 255 - (int) (log( 1.0 + 255.0 * (double) i*16.0 / 32767.0 ) * m); |
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| 87 | conv16to8[i] = c; |
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| 88 | } |
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| 89 | } |
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| 90 | else if(mode == AUDIO_FORMAT_SIGNED_8) { |
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| 91 | for(i=-2048;i<2048;i++) { |
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| 92 | conv16to8[i] = i>>4; |
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| 93 | } |
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| 94 | } |
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| 95 | else if(mode == AUDIO_FORMAT_UNSIGNED_8) { |
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| 96 | for(i=-2048;i<2048;i++) { |
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| 97 | conv16to8[i] = (i>>4)+128; |
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| 98 | } |
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| 99 | } |
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| 100 | else { |
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| 101 | for(i=-2048;i<2048;i++) { |
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| 102 | conv16to8[i] = 0; |
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| 103 | } |
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| 104 | } |
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| 105 | } |
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| 106 |