commit 935f2ec71601beca4d64e2b916ea69f35594fb32
author Yaowu Xu <yaowu@google.com> Tue Nov 12 14:49:06 2019 -0800
committer Yaowu Xu <yaowu@google.com> Wed Nov 13 15:55:32 2019 +0000
tree f481209d5307e8a764b3b02d1567c00e4f9aa7bf
parent 5c657492ec525e595170be51302121fda891199a

Change an operation order to avoid uint32 overflow

Also added a clamp to prevent from dividing by zero.

BUG=aomedia:2537

Change-Id: I2c843049f29f525b42cee7ddcbd3c2c66838d776

av1/encoder/ratectrl.c

diff --git a/av1/encoder/ratectrl.c b/av1/encoder/ratectrl.c
index e0e82e4..8e40e80 100644
--- a/av1/encoder/ratectrl.c
+++ b/av1/encoder/ratectrl.c
@@ -1705,9 +1705,9 @@
   RATE_CONTROL *const rc = &cpi->rc;
   int64_t vbr_bits_off_target = rc->vbr_bits_off_target;
   int max_delta;
-  const int frame_window =
-      AOMMIN(16, (int)cpi->twopass.total_stats.count -
-                     cpi->common.current_frame.frame_number);
+  const int frame_window = clamp((int)(cpi->twopass.total_stats.count -
+                                       cpi->common.current_frame.frame_number),
+                                 1, 16);
 
   max_delta = (vbr_bits_off_target > 0)
                   ? (int)(vbr_bits_off_target / frame_window)