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 FFmpeg.
7 *
8 * FFmpeg 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 * FFmpeg 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 FFmpeg; 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#define BITS 16
28#define FLOATFMT "%.18e"
29#define FIXEDFMT "%6d"
30
31static int clip_f15(int v)
32{
33    return v < -32767 ? -32767 :
34           v >  32767 ?  32767 :
35           v;
36}
37
38static void printval(double val, int fixed)
39{
40    if (fixed) {
41        /* lrint() isn't always available, so round and cast manually. */
42        double new_val = val * (double) (1 << 15);
43
44        new_val = new_val >= 0 ? floor(new_val + 0.5) : ceil(new_val - 0.5);
45
46        printf(" "FIXEDFMT",", clip_f15((long int) new_val));
47    } else {
48        printf(" "FLOATFMT",", val);
49    }
50}
51
52int main(int argc, char *argv[])
53{
54    int i, j;
55    int do_sin = argc > 1 && !strcmp(argv[1], "sin");
56    int fixed  = argc > 1 &&  strstr(argv[1], "fixed");
57    double (*func)(double) = do_sin ? sin : cos;
58
59    printf("/* This file was automatically generated. */\n");
60    printf("#define FFT_FLOAT %d\n", !fixed);
61    printf("#include \"libavcodec/%s\"\n", do_sin ? "rdft.h" : "fft.h");
62    for (i = 4; i <= BITS; i++) {
63        int m = 1 << i;
64        double freq = 2*3.14159265358979323846/m;
65        printf("%s(%i) = {\n   ", do_sin ? "SINTABLE" : "COSTABLE", m);
66        for (j = 0; j < m/2 - 1; j++) {
67            int idx = j > m/4 ? m/2 - j : j;
68            if (do_sin && j >= m/4)
69                idx = m/4 - j;
70            printval(func(idx*freq), fixed);
71            if ((j & 3) == 3)
72                printf("\n   ");
73        }
74        printval(func(do_sin ? -(m/4 - 1)*freq : freq), fixed);
75        printf("\n};\n");
76    }
77    return 0;
78}
79