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Diffstat (limited to 'third_party/ffmpeg/include/libavutil/random.h')
-rw-r--r-- | third_party/ffmpeg/include/libavutil/random.h | 73 |
1 files changed, 0 insertions, 73 deletions
diff --git a/third_party/ffmpeg/include/libavutil/random.h b/third_party/ffmpeg/include/libavutil/random.h deleted file mode 100644 index f243676..0000000 --- a/third_party/ffmpeg/include/libavutil/random.h +++ /dev/null @@ -1,73 +0,0 @@ -/* - * Mersenne Twister Random 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 - -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; - - -void av_init_random(unsigned int seed, AVRandomState *state); ///< 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. -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 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. - */ -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; -} - -/** Return random in range [0-1] as double. */ -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 */ |