external/srs
1
0
Fork 0
mirror of https://github.com/ossrs/srs.git synced 2025-03-09 15:49:59 +00:00
Code Issues Releases Wiki Activity

Rename ffmpeg-4.2-fit to ffmpeg-4-fit

Browse source
This commit is contained in:
winlin 2021-03-02 17:48:40 +08:00
parent b19074721c
commit 27712fdda7
720 changed files with 14 additions and 14 deletions
Download patch file Download diff file Expand all files Collapse all files

71
trunk/3rdparty/ffmpeg-4-fit/libavutil/lfg.h vendored Normal file
View file

@ -0,0 +1,71 @@
/*
* 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
#include <stdint.h>
typedef struct AVLFG {
unsigned int state[64];
int index;
} AVLFG;
void av_lfg_init(AVLFG *c, unsigned int seed);
/**
* Seed the state of the ALFG using binary data.
*
* Return value: 0 on success, negative value (AVERROR) on failure.
*/
int av_lfg_init_from_data(AVLFG *c, const uint8_t *data, unsigned int length);
/**
* 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 */