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author | Reimar Döffinger <Reimar.Doeffinger@gmx.de> | 2009-10-15 01:41:24 +0400 |
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committer | Reimar Döffinger <Reimar.Doeffinger@gmx.de> | 2009-10-15 01:41:24 +0400 |
commit | 16aec74761c2a0e6d782135083e570b8358593e1 (patch) | |
tree | aeca6a3459ee41e0f3d1d1b7d39365c5ac25ab17 /libavcodec/costablegen.c | |
parent | 6d924b5a5f39e33a02c4b39cc5892911bb508d4e (diff) |
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
Diffstat (limited to 'libavcodec/costablegen.c')
-rw-r--r-- | libavcodec/costablegen.c | 50 |
1 files changed, 50 insertions, 0 deletions
diff --git a/libavcodec/costablegen.c b/libavcodec/costablegen.c new file mode 100644 index 0000000000..c27d887795 --- /dev/null +++ b/libavcodec/costablegen.c @@ -0,0 +1,50 @@ +/* + * 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; +} |