[FFmpeg-cvslog] avcodec/motion_est: Fix xy indexing on range violation in ff_get_best_fcode()

[Michael Niedermayer]

ffmpeg | branch: release/3.4 | Michael Niedermayer <michael at niedermayer.cc> | Tue Feb  8 21:38:50 2022 +0100| [5ead85030294e18131dc1f675ea7547babf50b8f] | committer: Michael Niedermayer

avcodec/motion_est: Fix xy indexing on range violation in ff_get_best_fcode()

This codepath seems untested, no testcases change

Found-by: <mkver>
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
(cherry picked from commit 634312a70f4d5afd40058c52b4d8eade1da07a70)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=5ead85030294e18131dc1f675ea7547babf50b8f
---

 libavcodec/motion_est.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/libavcodec/motion_est.c b/libavcodec/motion_est.c
index 316d16a77b..310925c2da 100644
--- a/libavcodec/motion_est.c
+++ b/libavcodec/motion_est.c
@@ -1634,7 +1634,7 @@ int ff_get_best_fcode(MpegEncContext * s, int16_t (*mv_table)[2], int type)
         for(y=0; y<s->mb_height; y++){
             int x;
             int xy= y*s->mb_stride;
-            for(x=0; x<s->mb_width; x++){
+            for(x=0; x<s->mb_width; x++, xy++){
                 if(s->mb_type[xy] & type){
                     int mx= mv_table[xy][0];
                     int my= mv_table[xy][1];
@@ -1651,7 +1651,6 @@ int ff_get_best_fcode(MpegEncContext * s, int16_t (*mv_table)[2], int type)
                             score[j]-= 170;
                     }
                 }
-                xy++;
             }
         }