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 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#include "libavutil/mathematics.h"
28
29#define BITS 17
30#define FLOATFMT "%.18e"
31#define FIXEDFMT "%6d"
32
33static int clip_f15(int v)
34{
35    return v < -32767 ? -32767 :
36           v >  32767 ?  32767 :
37           v;
38}
39
40static void printval(double val, int fixed)
41{
42    if (fixed) {
43        /* lrint() isn't always available, so round and cast manually. */
44        double new_val = val * (double) (1 << 15);
45
46        new_val = new_val >= 0 ? floor(new_val + 0.5) : ceil(new_val - 0.5);
47
48        printf(" "FIXEDFMT",", clip_f15((long int) new_val));
49    } else {
50        printf(" "FLOATFMT",", val);
51    }
52}
53
54int main(int argc, char *argv[])
55{
56    int i, j;
57    int do_sin = argc > 1 && !strcmp(argv[1], "sin");
58    int fixed  = argc > 1 &&  strstr(argv[1], "fixed");
59    double (*func)(double) = do_sin ? sin : cos;
60
61    printf("/* This file was automatically generated. */\n");
62    printf("#define FFT_FLOAT %d\n", !fixed);
63    printf("#include \"libavcodec/%s\"\n", do_sin ? "rdft.h" : "fft.h");
64    for (i = 4; i <= BITS; i++) {
65        int m = 1 << i;
66        double freq = 2*M_PI/m;
67        printf("%s(%i) = {\n   ", do_sin ? "SINTABLE" : "COSTABLE", m);
68        for (j = 0; j < m/2 - 1; j++) {
69            int idx = j > m/4 ? m/2 - j : j;
70            if (do_sin && j >= m/4)
71                idx = m/4 - j;
72            printval(func(idx*freq), fixed);
73            if ((j & 3) == 3)
74                printf("\n   ");
75        }
76        printval(func(do_sin ? -(m/4 - 1)*freq : freq), fixed);
77        printf("\n};\n");
78    }
79    return 0;
80}
81