diff options
author | Sven Gothel <[email protected]> | 2013-08-25 09:06:11 +0200 |
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committer | Sven Gothel <[email protected]> | 2013-08-25 09:06:11 +0200 |
commit | 640dbb2e1780a6074b932a455252bb410e4393de (patch) | |
tree | 720da42ece2392cf734a1e48fe053e7bf558cf20 /make/stub_includes/libav/lavc53.lavf53.lavu51/libavutil/lfg.h | |
parent | d0aee05031cd52ad4f6753a8859a21e77845bc35 (diff) |
libav/ffmpeg: Move current lavc53.lavf53.lavu51 (version 8) header files to their sub-folders; Add lavc54.lavf54.lavu52 (version 9) header files
lavc54.lavf54.lavu52:
- Begin testing w/ version 9
- Header files are binary incompatible (data types)
Default is still lavc53.lavf53.lavu51
Diffstat (limited to 'make/stub_includes/libav/lavc53.lavf53.lavu51/libavutil/lfg.h')
-rw-r--r-- | make/stub_includes/libav/lavc53.lavf53.lavu51/libavutil/lfg.h | 62 |
1 files changed, 62 insertions, 0 deletions
diff --git a/make/stub_includes/libav/lavc53.lavf53.lavu51/libavutil/lfg.h b/make/stub_includes/libav/lavc53.lavf53.lavu51/libavutil/lfg.h new file mode 100644 index 000000000..904d00a66 --- /dev/null +++ b/make/stub_includes/libav/lavc53.lavf53.lavu51/libavutil/lfg.h @@ -0,0 +1,62 @@ +/* + * Lagged Fibonacci PRNG + * Copyright (c) 2008 Michael Niedermayer + * + * This file is part of Libav. + * + * Libav 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. + * + * Libav 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 Libav; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#ifndef AVUTIL_LFG_H +#define AVUTIL_LFG_H + +typedef struct { + unsigned int state[64]; + int index; +} AVLFG; + +void av_lfg_init(AVLFG *c, unsigned int seed); + +/** + * Get the next random unsigned 32-bit number using an ALFG. + * + * Please also consider a simple LCG like state= state*1664525+1013904223, + * it may be good enough and faster for your specific use case. + */ +static inline unsigned int av_lfg_get(AVLFG *c){ + c->state[c->index & 63] = c->state[(c->index-24) & 63] + c->state[(c->index-55) & 63]; + return c->state[c->index++ & 63]; +} + +/** + * Get the next random unsigned 32-bit number using a MLFG. + * + * Please also consider av_lfg_get() above, it is faster. + */ +static inline unsigned int av_mlfg_get(AVLFG *c){ + unsigned int a= c->state[(c->index-55) & 63]; + unsigned int b= c->state[(c->index-24) & 63]; + return c->state[c->index++ & 63] = 2*a*b+a+b; +} + +/** + * Get the next two numbers generated by a Box-Muller Gaussian + * generator using the random numbers issued by lfg. + * + * @param out array where the two generated numbers are placed + */ +void av_bmg_get(AVLFG *lfg, double out[2]); + +#endif /* AVUTIL_LFG_H */ |