X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=libavutil%2Flfg.h;h=5e526c1dae21e745d527bda9ed800e25490818ab;hb=1546a41adae818b340acdd9b5dacd6d0a92b6507;hp=3d3f9332abfd6a72cb5e183845d967a14c7ca5f1;hpb=310d442456881e448d22afa9d8b1a8687b5dd2bf;p=ffmpeg

diff --git a/libavutil/lfg.h b/libavutil/lfg.h
index 3d3f9332abf..5e526c1dae2 100644
--- a/libavutil/lfg.h
+++ b/libavutil/lfg.h
@@ -2,27 +2,27 @@
  * Lagged Fibonacci PRNG
  * Copyright (c) 2008 Michael Niedermayer
  *
- * This file is part of FFmpeg.
+ * This file is part of Libav.
  *
- * FFmpeg is free software; you can redistribute it and/or
+ * 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.
  *
- * FFmpeg is distributed in the hope that it will be useful,
+ * 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 FFmpeg; if not, write to the Free Software
+ * License along with Libav; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
-#ifndef FFMPEG_LFG_H
-#define FFMPEG_LFG_H
+#ifndef AVUTIL_LFG_H
+#define AVUTIL_LFG_H
 
-typedef struct {
+typedef struct AVLFG {
     unsigned int state[64];
     int index;
 } AVLFG;
@@ -30,7 +30,7 @@ typedef struct {
 void av_lfg_init(AVLFG *c, unsigned int seed);
 
 /**
- * Gets the next random unsigned 32bit number using a ALFG.
+ * 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.
@@ -41,14 +41,22 @@ static inline unsigned int av_lfg_get(AVLFG *c){
 }
 
 /**
- * Gets the next random unsigned 32bit number using a MLFG.
+ * Get the next random unsigned 32-bit number using a MLFG.
  *
- * Please also consider the av_lfg_get() above, it is faster.
+ * 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] = a*b+a+b;
+    return c->state[c->index++ & 63] = 2*a*b+a+b;
 }
 
-#endif //FFMPEG_LFG_H
+/**
+ * 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 */