96 lines
3.7 KiB
C
96 lines
3.7 KiB
C
/*
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* Copyright (c) Michael Hipp and other authors of the mpglib project.
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* This library 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 GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
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*/
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#include <stdlib.h>
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#include "mpg123.h"
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real decwin[512+32];
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static real cos64[16],cos32[8],cos16[4],cos8[2],cos4[1];
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real *pnts[] = { cos64,cos32,cos16,cos8,cos4 };
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#if 0
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static unsigned char *conv16to8_buf = NULL;
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unsigned char *conv16to8;
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#endif
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static const 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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void make_decode_tables(long scaleval)
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{
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int i,j,k,kr,divv;
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real *table,*costab;
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for(i=0;i<5;i++)
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{
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kr=0x10>>i; 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] = 1.0 / (2.0 * cos(M_PI * ((double) k * 2.0 + 1.0) / (double) divv));
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}
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table = decwin;
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scaleval = -scaleval;
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for(i=0,j=0;i<256;i++,j++,table+=32)
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{
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if(table < decwin+512+16)
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table[16] = table[0] = (double) intwinbase[j] / 65536.0 * (double) scaleval;
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if(i % 32 == 31)
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table -= 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=256 */ ;i<512;i++,j--,table+=32)
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{
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if(table < decwin+512+16)
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table[16] = table[0] = (double) intwinbase[j] / 65536.0 * (double) scaleval;
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if(i % 32 == 31)
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table -= 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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