diff options
| -rw-r--r-- | libavutil/lfg.h | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/libavutil/lfg.h b/libavutil/lfg.h index 36c36f446b..3d3f9332ab 100644 --- a/libavutil/lfg.h +++ b/libavutil/lfg.h @@ -30,7 +30,7 @@ typedef struct { void av_lfg_init(AVLFG *c, unsigned int seed); /** - * Gets the next random unsigned 32bit number. + * Gets the next random unsigned 32bit number using a ALFG. * * Please also consider a simple LCG like state= state*1664525+1013904223, * it may be good enough and faster for your specific use case. @@ -40,4 +40,15 @@ static inline unsigned int av_lfg_get(AVLFG *c){ return c->state[c->index++ & 63]; } +/** + * Gets the next random unsigned 32bit number using a MLFG. + * + * Please also consider the 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] = a*b+a+b; +} + #endif //FFMPEG_LFG_H |