ffmpeg/libavcodec/costablegen.c
Reimar Döffinger 16aec74761 Use hardcoded instead of runtime-calculated ff_cos_* tables if
--enable-hardcoded-tables was used.
Due to the size, the code for the tables is generated at compile time.

Originally committed as revision 20232 to svn://svn.ffmpeg.org/ffmpeg/trunk
2009-10-14 21:41:24 +00:00

51 lines
1.6 KiB
C

/*
* Generate a header file for hardcoded ff_cos_* tables
*
* Copyright (c) 2009 Reimar Döffinger <Reimar.Doeffinger@gmx.de>
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <stdio.h>
#include <math.h>
#ifndef M_PI
#define M_PI 3.14159265358979323846
#endif
#define BITS 16
#define FLOATFMT "%.18e"
int main(void)
{
int i, j;
printf("/* This file was generated by libavcodec/costablegen */\n");
printf("#include \"dsputil.h\"\n");
for (i = 4; i <= BITS; i++) {
int m = 1 << i;
double freq = 2*M_PI/m;
printf("const DECLARE_ALIGNED_16(FFTSample, ff_cos_%i[]) = {\n ", m);
for (j = 0; j < m/2 - 1; j++) {
int idx = j > m/4 ? m/2 - j : j;
printf(" "FLOATFMT",", cos(idx*freq));
if ((j & 3) == 3)
printf("\n ");
}
printf(" "FLOATFMT"\n};\n", cos(freq));
}
return 0;
}