2 * Generate a header file for hardcoded ff_cos_* tables
4 * Copyright (c) 2009 Reimar Döffinger <Reimar.Doeffinger@gmx.de>
6 * This file is part of FFmpeg.
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.
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.
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
28 #define FLOATFMT "%.18e"
29 #define FIXEDFMT "%6d"
31 static int clip_f15(int v)
33 return v < -32767 ? -32767 :
38 static void printval(double val, int fixed)
41 /* lrint() isn't always available, so round and cast manually. */
42 double new_val = val * (double) (1 << 15);
44 new_val = new_val >= 0 ? floor(new_val + 0.5) : ceil(new_val - 0.5);
46 printf(" "FIXEDFMT",", clip_f15((long int) new_val));
48 printf(" "FLOATFMT",", val);
52 int main(int argc, char *argv[])
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;
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++) {
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)
70 printval(func(idx*freq), fixed);
74 printval(func(do_sin ? -(m/4 - 1)*freq : freq), fixed);