X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=libavutil%2Flfg.h;h=2b669205d18995d12bd6689bd724fc33e07b803e;hb=8b3e6ce5f4ab1ebf3a54ff7e0ff440a1a5f842f7;hp=03f779ad8a4d2957bc72447c7ca17b2863120338;hpb=06476249cd2332e30b66576633b2827adf3478dd;p=ffmpeg

diff --git a/libavutil/lfg.h b/libavutil/lfg.h
index 03f779ad8a4..2b669205d18 100644
--- a/libavutil/lfg.h
+++ b/libavutil/lfg.h
@@ -24,6 +24,12 @@
 
 #include <stdint.h>
 
+/**
+ * Context structure for the Lagged Fibonacci PRNG.
+ * The exact layout, types and content of this struct may change and should
+ * not be accessed directly. Only its sizeof() is guranteed to stay the same
+ * to allow easy instanciation.
+ */
 typedef struct AVLFG {
     unsigned int state[64];
     int index;
@@ -45,8 +51,9 @@ int av_lfg_init_from_data(AVLFG *c, const uint8_t *data, unsigned int length);
  * 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];
+    unsigned a = c->state[c->index & 63] = c->state[(c->index-24) & 63] + c->state[(c->index-55) & 63];
+    c->index += 1U;
+    return a;
 }
 
 /**
@@ -57,7 +64,9 @@ static inline unsigned int av_lfg_get(AVLFG *c){
 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;
+    a = c->state[c->index & 63] = 2*a*b+a+b;
+    c->index += 1U;
+    return a;
 }
 
 /**