--- a/media/ffvpx/libavcodec/vp9.c
+++ b/media/ffvpx/libavcodec/vp9.c
@@ -3700,21 +3700,20 @@ static void set_tile_offset(int *start, 
 static av_always_inline void adapt_prob(uint8_t *p, unsigned ct0, unsigned ct1,
                                         int max_count, int update_factor)
 {
     unsigned ct = ct0 + ct1, p2, p1;
 
     if (!ct)
         return;
 
+    update_factor = FASTDIV(update_factor * FFMIN(ct, max_count), max_count);
     p1 = *p;
-    p2 = ((ct0 << 8) + (ct >> 1)) / ct;
+    p2 = ((((int64_t) ct0) << 8) + (ct >> 1)) / ct;
     p2 = av_clip(p2, 1, 255);
-    ct = FFMIN(ct, max_count);
-    update_factor = FASTDIV(update_factor * ct, max_count);
 
     // (p1 * (256 - update_factor) + p2 * update_factor + 128) >> 8
     *p = p1 + (((p2 - p1) * update_factor + 128) >> 8);
 }
 
 static void adapt_probs(VP9Context *s)
 {
     int i, j, k, l, m;