Revision cbfd34246cdddc58a627dd10fc563245601b2162 authored by Laurent Aimar on 08 October 2011, 21:40:41 UTC, committed by Michael Niedermayer on 04 November 2011, 00:23:56 UTC
It prevents leaving the AVPacket uninitialized. Signed-off-by: Michael Niedermayer <michaelni@gmx.at> (cherry picked from commit bc38e83793be5f7a184c88be55e556453a25224b) Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
1 parent feef77e
lfg.h
/*
* Lagged Fibonacci PRNG
* Copyright (c) 2008 Michael Niedermayer
*
* 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_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 */
![swh spinner](/static/img/swh-spinner.gif)
Computing file changes ...