Statistics
| Branch: | Revision:

ffmpeg / libavcodec / costablegen.c @ 2912e87a

History | View | Annotate | Download (1.81 KB)

1
/*
2
 * Generate a header file for hardcoded ff_cos_* tables
3
 *
4
 * Copyright (c) 2009 Reimar Döffinger <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

    
33
int main(int argc, char *argv[])
34
{
35
    int i, j;
36
    int do_sin = argc == 2 && !strcmp(argv[1], "sin");
37
    double (*func)(double) = do_sin ? sin : cos;
38

    
39
    printf("/* This file was generated by libavcodec/costablegen */\n");
40
    printf("#include \"libavcodec/fft.h\"\n");
41
    for (i = 4; i <= BITS; i++) {
42
        int m = 1 << i;
43
        double freq = 2*M_PI/m;
44
        printf("%s(%i) = {\n   ", do_sin ? "SINTABLE" : "COSTABLE", m);
45
        for (j = 0; j < m/2 - 1; j++) {
46
            int idx = j > m/4 ? m/2 - j : j;
47
            if (do_sin && j >= m/4)
48
                idx = m/4 - j;
49
            printf(" "FLOATFMT",", func(idx*freq));
50
            if ((j & 3) == 3)
51
                printf("\n   ");
52
        }
53
        printf(" "FLOATFMT"\n};\n", func(do_sin ? -(m/4 - 1)*freq : freq));
54
    }
55
    return 0;
56
}