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authorMohamed Tarek <mt@rockbox.org>2009-05-11 23:35:50 +0000
committerMohamed Tarek <mt@rockbox.org>2009-05-11 23:35:50 +0000
commit0cb3ad58b3033ec1b78cc74943775e27ae7faeca (patch)
tree4c3a648b639b9f0f442f2594543e6eaaba430618 /apps/codecs/libcook/libavutil/lfg.h
parent685cee87bedc06549fba38ea87f1d3461ba4a0fe (diff)
downloadrockbox-0cb3ad58b3033ec1b78cc74943775e27ae7faeca.tar.gz
rockbox-0cb3ad58b3033ec1b78cc74943775e27ae7faeca.zip
-Took cook_random() from an old cook.c revision [6 mar 2007], which is a
simple RNG, to eliminate the need for lfg.c/h. -Remove lfg.c/h and md5.c/h as they are no longer needed and use the more common form of my name in docs/COMMITTERS. git-svn-id: svn://svn.rockbox.org/rockbox/trunk@20915 a1c6a512-1295-4272-9138-f99709370657
Diffstat (limited to 'apps/codecs/libcook/libavutil/lfg.h')
-rw-r--r--apps/codecs/libcook/libavutil/lfg.h54
1 files changed, 0 insertions, 54 deletions
diff --git a/apps/codecs/libcook/libavutil/lfg.h b/apps/codecs/libcook/libavutil/lfg.h
deleted file mode 100644
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--- a/apps/codecs/libcook/libavutil/lfg.h
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@@ -1,54 +0,0 @@
1/*
2 * Lagged Fibonacci PRNG
3 * Copyright (c) 2008 Michael Niedermayer
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22#ifndef AVUTIL_LFG_H
23#define AVUTIL_LFG_H
24
25typedef struct {
26 unsigned int state[64];
27 int index;
28} AVLFG;
29
30void av_lfg_init(AVLFG *c, unsigned int seed);
31
32/**
33 * Gets the next random unsigned 32-bit number using an ALFG.
34 *
35 * Please also consider a simple LCG like state= state*1664525+1013904223,
36 * it may be good enough and faster for your specific use case.
37 */
38static inline unsigned int av_lfg_get(AVLFG *c){
39 c->state[c->index & 63] = c->state[(c->index-24) & 63] + c->state[(c->index-55) & 63];
40 return c->state[c->index++ & 63];
41}
42
43/**
44 * Gets the next random unsigned 32-bit number using a MLFG.
45 *
46 * Please also consider av_lfg_get() above, it is faster.
47 */
48static inline unsigned int av_mlfg_get(AVLFG *c){
49 unsigned int a= c->state[(c->index-55) & 63];
50 unsigned int b= c->state[(c->index-24) & 63];
51 return c->state[c->index++ & 63] = 2*a*b+a+b;
52}
53
54#endif /* AVUTIL_LFG_H */