1/*
2 * Generate a header file for hardcoded ff_cos_* tables
3 *
4 * Copyright (c) 2009 Reimar D��ffinger <Reimar.Doeffinger@gmx.de>
5 *
6 * This file is part of Libav.
7 *
8 * Libav is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; either
11 * version 2.1 of the License, or (at your option) any later version.
12 *
13 * Libav is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16 * Lesser General Public License for more details.
17 *
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with Libav; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 */
22
23#include <stdio.h>
24#include <string.h>
25#include <math.h>
26
27#ifndef M_PI
28#define M_PI 3.14159265358979323846
29#endif
30#define BITS 16
31#define FLOATFMT "%.18e"
32#define FIXEDFMT "%6d"
33
34static int clip_f15(int v)
35{
36    return v < -32767 ? -32767 :
37           v >  32767 ?  32767 :
38           v;
39}
40
41static void printval(double val, int fixed)
42{
43    if (fixed)
44        printf(" "FIXEDFMT",", clip_f15(lrint(val * (double)(1<<15))));
45    else
46        printf(" "FLOATFMT",", val);
47
48}
49
50int main(int argc, char *argv[])
51{
52    int i, j;
53    int do_sin = argc > 1 && !strcmp(argv[1], "sin");
54    int fixed  = argc > 1 &&  strstr(argv[1], "fixed");
55    double (*func)(double) = do_sin ? sin : cos;
56
57    printf("/* This file was automatically generated. */\n");
58    printf("#define CONFIG_FFT_FLOAT %d\n", !fixed);
59    printf("#include \"libavcodec/%s\"\n", do_sin ? "rdft.h" : "fft.h");
60    for (i = 4; i <= BITS; i++) {
61        int m = 1 << i;
62        double freq = 2*M_PI/m;
63        printf("%s(%i) = {\n   ", do_sin ? "SINTABLE" : "COSTABLE", m);
64        for (j = 0; j < m/2 - 1; j++) {
65            int idx = j > m/4 ? m/2 - j : j;
66            if (do_sin && j >= m/4)
67                idx = m/4 - j;
68            printval(func(idx*freq), fixed);
69            if ((j & 3) == 3)
70                printf("\n   ");
71        }
72        printval(func(do_sin ? -(m/4 - 1)*freq : freq), fixed);
73        printf("\n};\n");
74    }
75    return 0;
76}
77