From: diego Date: Sat, 21 Mar 2009 17:28:38 +0000 (+0000) Subject: Remove deprecated and now unused Mersenne Twister PRNG. X-Git-Url: http://rtime.felk.cvut.cz/gitweb/frescor/ffmpeg.git/commitdiff_plain/7092231bbf52120dc92d2d4ec44a124f6dfb37ab Remove deprecated and now unused Mersenne Twister PRNG. git-svn-id: file:///var/local/repositories/ffmpeg/trunk@18116 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b --- diff --git a/libavutil/Makefile b/libavutil/Makefile index a5f247e1f..2ea95e76c 100644 --- a/libavutil/Makefile +++ b/libavutil/Makefile @@ -34,7 +34,6 @@ OBJS = adler32.o \ mathematics.o \ md5.o \ mem.o \ - random.o \ random_seed.o \ rational.o \ rc4.o \ @@ -42,7 +41,7 @@ OBJS = adler32.o \ tree.o \ utils.o \ -TESTS = $(addsuffix -test$(EXESUF), adler32 aes base64 crc des lls md5 pca random sha1 softfloat tree) +TESTS = $(addsuffix -test$(EXESUF), adler32 aes base64 crc des lls md5 pca sha1 softfloat tree) DIRS = arm bfin sh4 x86 diff --git a/libavutil/random.c b/libavutil/random.c deleted file mode 100644 index 94671556f..000000000 --- a/libavutil/random.c +++ /dev/null @@ -1,99 +0,0 @@ -/* - * Mersenne Twister PRNG algorithm - * Copyright (c) 2006 Ryan Martell - * Based on a C program for MT19937, with initialization improved 2002/1/26. - * Coded by Takuji Nishimura and Makoto Matsumoto. - * - * 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 - */ - - -/** - * See http://en.wikipedia.org/wiki/Mersenne_twister - * for an explanation of this algorithm. - */ -#include -#include "random.h" - - -/* period parameters */ -#define M 397 -#define A 0x9908b0df /* constant vector a */ -#define UPPER_MASK 0x80000000 /* most significant w-r bits */ -#define LOWER_MASK 0x7fffffff /* least significant r bits */ - -/** Initializes mt[AV_RANDOM_N] with a seed. */ -void av_random_init(AVRandomState *state, unsigned int seed) -{ - int index; - - /* - This differs from the Wikipedia article. Source is from the - Makoto Matsumoto and Takuji Nishimura code, with the following comment: - */ - /* See Knuth TAOCP Vol2. 3rd Ed. P.106 for multiplier. */ - /* In the previous versions, MSBs of the seed affect */ - /* only MSBs of the array mt[]. */ - state->mt[0] = seed & 0xffffffff; - for (index = 1; index < AV_RANDOM_N; index++) { - unsigned int prev= state->mt[index - 1]; - state->mt[index] = (1812433253UL * (prev ^ (prev>>30)) + index) & 0xffffffff; - } - state->index= index; // Will cause it to generate untempered numbers in the first iteration. -} - -/** Generates AV_RANDOM_N words at one time (which will then be tempered later). - * av_random calls this; you shouldn't. */ -void av_random_generate_untempered_numbers(AVRandomState *state) -{ - int kk; - unsigned int y; - - for (kk = 0; kk < AV_RANDOM_N - M; kk++) { - y = (state->mt[kk] & UPPER_MASK) | (state->mt[kk + 1] & LOWER_MASK); - state->mt[kk] = state->mt[kk + M] ^ (y >> 1) ^ ((y&1)*A); - } - for (; kk < AV_RANDOM_N - 1; kk++) { - y = (state->mt[kk] & UPPER_MASK) | (state->mt[kk + 1] & LOWER_MASK); - state->mt[kk] = state->mt[kk + (M - AV_RANDOM_N)] ^ (y >> 1) ^ ((y&1)*A); - } - y = (state->mt[AV_RANDOM_N - 1] & UPPER_MASK) | (state->mt[0] & LOWER_MASK); - state->mt[AV_RANDOM_N - 1] = state->mt[M - 1] ^ (y >> 1) ^ ((y&1)*A); - state->index = 0; -} - -#ifdef TEST -#include "common.h" -#include "log.h" -int main(void) -{ - int x=0; - int i, j; - AVRandomState state; - - av_random_init(&state, 0xdeadbeef); - for (j = 0; j < 10000; j++) { - START_TIMER - for (i = 0; i < 624; i++) { - x+= av_random(&state); - } - STOP_TIMER("624 calls of av_random"); - } - av_log(NULL, AV_LOG_ERROR, "final value:%X\n", x); - return 0; -} -#endif diff --git a/libavutil/random.h b/libavutil/random.h deleted file mode 100644 index ed4c0ac84..000000000 --- a/libavutil/random.h +++ /dev/null @@ -1,76 +0,0 @@ -/* - * Mersenne Twister PRNG algorithm - * Copyright (c) 2006 Ryan Martell - * Based on a C program for MT19937, with initialization improved 2002/1/26. - * Coded by Takuji Nishimura and Makoto Matsumoto. - * - * 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 - */ - -#ifndef AVUTIL_RANDOM_H -#define AVUTIL_RANDOM_H - -#define AV_RANDOM_N 624 - -#include "avutil.h" -#include "common.h" - -typedef struct { - unsigned int mt[AV_RANDOM_N]; ///< the array for the state vector - int index; ///< Current untempered value we use as the base. -} AVRandomState; - - -attribute_deprecated void av_random_init(AVRandomState *state, unsigned int seed); ///< To be inlined, the struct must be visible. So it does not make sense to try and keep it opaque with malloc/free-like calls. -attribute_deprecated void av_random_generate_untempered_numbers(AVRandomState *state); ///< Regenerate the untempered numbers (must be done every 624 iterations, or it will loop). - -/** - * Generates a random number from the interval [0,0xffffffff]. - * - * Please do NOT use the Mersenne Twister, it is slow. Use the random number - * generator from lfg.c/h or a simple LCG like state = state*1664525+1013904223. - * If you still choose to use MT, expect that you will have to provide - * some evidence that it makes a difference for the case where you use it. - */ -attribute_deprecated static inline unsigned int av_random(AVRandomState *state) -{ - unsigned int y; - - // Regenerate the untempered numbers if we should... - if (state->index >= AV_RANDOM_N) - av_random_generate_untempered_numbers(state); - - // Grab one... - y = state->mt[state->index++]; - - /* Now temper (Mersenne Twister coefficients). The coefficients for MT19937 are.. */ - y ^= (y >> 11); - y ^= (y << 7) & 0x9d2c5680; - y ^= (y << 15) & 0xefc60000; - y ^= (y >> 18); - - return y; -} - -/** Returns a random number in the range [0-1] as double. */ -attribute_deprecated static inline double av_random_real1(AVRandomState *state) -{ - /* divided by 2^32-1 */ - return av_random(state) * (1.0 / 4294967296.0); -} - -#endif /* AVUTIL_RANDOM_H */