117 lines
3.1 KiB
C
117 lines
3.1 KiB
C
/*
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* SpanDSP - a series of DSP components for telephony
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*
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* make_fixed_point_math_tables.c - Generate lookup tables for some of the
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* fixed point maths functions.
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*
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* Written by Steve Underwood <steveu@coppice.org>
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*
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* Copyright (C) 2010 Steve Underwood
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*
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* All rights reserved.
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*
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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 version 2, as
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* published by the Free Software Foundation.
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*
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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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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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#if defined(HAVE_CONFIG_H)
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#include "config.h"
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#endif
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#include <inttypes.h>
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#include <stdlib.h>
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#include <stdio.h>
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#include <fcntl.h>
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#include <memory.h>
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#include <math.h>
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int main(int argc, char *argv[])
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{
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int i;
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double val;
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int ival;
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printf("static const uint16_t fixed_reciprocal_table[129] =\n");
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printf("{\n");
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for (i = 0; i < 129; i++)
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{
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val = 32768.0*128.0/(128 + i) + 0.5;
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ival = val;
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if (i < 128)
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printf(" %6d,\n", ival);
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else
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printf(" %6d\n", ival);
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}
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printf("};\n\n");
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printf("static const uint16_t fixed_sqrt_table[193] =\n");
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printf("{\n");
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for (i = 64; i <= 256; i++)
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{
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ival = sqrt(i/256.0)*65536.0 + 0.5;
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if (ival > 65535)
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ival = 65535;
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if (i < 256)
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printf(" %6d,\n", ival);
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else
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printf(" %6d\n", ival);
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}
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printf("};\n\n");
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printf("static const int16_t fixed_log10_table[129] =\n");
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printf("{\n");
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for (i = 128; i <= 256; i++)
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{
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ival = log10(i/256.0)*32768.0 - 0.5;
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if (i <= 255)
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printf(" %6d,\n", ival);
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else
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printf(" %6d\n", ival);
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}
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printf("};\n\n");
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printf("static const int16_t fixed_sine_table[257] =\n");
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printf("{\n");
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for (i = 0; i <= 256; i++)
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{
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val = sin(i*3.1415926535/512.0)*32768.0;
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ival = val + 0.5;
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if (ival > 32767)
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ival = 32767;
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if (i <= 255)
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printf(" %6d,\n", ival);
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else
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printf(" %6d\n", ival);
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}
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printf("};\n\n");
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printf("static const uint16_t fixed_arctan_table[257] =\n");
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printf("{\n");
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for (i = 0; i <= 256; i++)
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{
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val = atan(i/256.0)*65536.0/(2.0*3.1415926535);
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ival = val + 0.5;
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/* Nudge the result away from zero, so things sit consistently on
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the correct side of the axes. */
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if (ival == 0)
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ival = 1;
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if (i <= 255)
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printf(" %6d,\n", ival);
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else
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printf(" %6d\n", ival);
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}
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printf("};\n\n");
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return 0;
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}
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