102 lines
3.6 KiB
102 lines
3.6 KiB
/* |
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tabinit.c - compact version of famous library mpg123 |
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Copyright (C) 2017 Uncle Mike |
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This program is free software: you can redistribute it and/or modify |
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it under the terms of the GNU General Public License as published by |
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the Free Software Foundation, either version 3 of the License, or |
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(at your option) any later version. |
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This program is distributed in the hope that it will be useful, |
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but WITHOUT ANY WARRANTY; without even the implied warranty of |
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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GNU General Public License for more details. |
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*/ |
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#include "mpg123.h" |
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#include <math.h> |
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static float cos64[16]; |
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static float cos32[8]; |
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static float cos16[4]; |
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static float cos8[2]; |
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static float cos4[1]; |
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static long intwinbase[] = { |
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0, -1, -1, -1, -1, -1, -1, -2, -2, -2, |
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-2, -3, -3, -4, -4, -5, -5, -6, -7, -7, |
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-8, -9, -10, -11, -13, -14, -16, -17, -19, -21, |
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-24, -26, -29, -31, -35, -38, -41, -45, -49, -53, |
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-58, -63, -68, -73, -79, -85, -91, -97, -104, -111, |
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-117, -125, -132, -139, -147, -154, -161, -169, -176, -183, |
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-190, -196, -202, -208, -213, -218, -222, -225, -227, -228, |
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-228, -227, -224, -221, -215, -208, -200, -189, -177, -163, |
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-146, -127, -106, -83, -57, -29, 2, 36, 72, 111, |
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153, 197, 244, 294, 347, 401, 459, 519, 581, 645, |
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711, 779, 848, 919, 991, 1064, 1137, 1210, 1283, 1356, |
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1428, 1498, 1567, 1634, 1698, 1759, 1817, 1870, 1919, 1962, |
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2001, 2032, 2057, 2075, 2085, 2087, 2080, 2063, 2037, 2000, |
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1952, 1893, 1822, 1739, 1644, 1535, 1414, 1280, 1131, 970, |
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794, 605, 402, 185, -45, -288, -545, -814, -1095, -1388, |
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-1692, -2006, -2330, -2663, -3004, -3351, -3705, -4063, -4425, -4788, |
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-5153, -5517, -5879, -6237, -6589, -6935, -7271, -7597, -7910, -8209, |
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-8491, -8755, -8998, -9219, -9416, -9585, -9727, -9838, -9916, -9959, |
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-9966, -9935, -9863, -9750, -9592, -9389, -9139, -8840, -8492, -8092, |
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-7640, -7134, -6574, -5959, -5288, -4561, -3776, -2935, -2037, -1082, |
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-70, 998, 2122, 3300, 4533, 5818, 7154, 8540, 9975, 11455, |
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12980, 14548, 16155, 17799, 19478, 21189, 22929, 24694, 26482, 28289, |
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30112, 31947, 33791, 35640, 37489, 39336, 41176, 43006, 44821, 46617, |
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48390, 50137, 51853, 53534, 55178, 56778, 58333, 59838, 61289, 62684, |
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64019, 65290, 66494, 67629, 68692, 69679, 70590, 71420, 72169, 72835, |
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73415, 73908, 74313, 74630, 74856, 74992, 75038 }; |
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float *pnts[] = { cos64, cos32, cos16, cos8, cos4 }; |
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void prepare_decode_tables( void ) |
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{ |
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int i, k, kr, divv; |
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float *costab; |
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for( i = 0; i < 5; i++ ) |
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{ |
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kr = 0x10 >> i; |
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divv = 0x40 >> i; |
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costab = pnts[i]; |
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for( k = 0; k < kr; k++) |
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costab[k] = DOUBLE_TO_REAL( 1.0 / ( 2.0 * cos( M_PI * ((double)k * 2.0 + 1.0 ) / (double)divv ))); |
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} |
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} |
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void make_decode_tables( mpg123_handle_t *fr ) |
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{ |
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int i, j; |
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int idx = 0; |
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double scaleval; |
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// scale is always based on 1.0. |
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scaleval = -0.5 * (fr->lastscale < 0 ? fr->p.outscale : fr->lastscale); |
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for( i = 0, j = 0; i < 256; i++, j++, idx += 32 ) |
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{ |
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if( idx < 512 + 16 ) |
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fr->decwin[idx+16] = fr->decwin[idx] = DOUBLE_TO_REAL( (double)intwinbase[j] * scaleval ); |
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if( i % 32 == 31 ) |
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idx -= 1023; |
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if( i % 64 == 63 ) |
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scaleval = -scaleval; |
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} |
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for( ; i < 512; i++, j--, idx += 32 ) |
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{ |
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if( idx < 512 + 16 ) |
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fr->decwin[idx+16] = fr->decwin[idx] = DOUBLE_TO_REAL( (double)intwinbase[j] * scaleval ); |
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if( i % 32 == 31 ) |
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idx -= 1023; |
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if( i % 64 == 63 ) |
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scaleval = -scaleval; |
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} |
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}
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