[FFmpeg-devel] [PATCH] lavfi/deshake: fix deshake crash issue.

[Jun Zhao]

Fixes ticket #7441.

Signed-off-by: Jun Zhao <mypopydev at gmail.com>
---
 libavfilter/vf_deshake.c |   12 +++++++-----
 1 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/libavfilter/vf_deshake.c b/libavfilter/vf_deshake.c
index 55ce5e1..5d2c7fa 100644
--- a/libavfilter/vf_deshake.c
+++ b/libavfilter/vf_deshake.c
@@ -196,11 +196,13 @@ static int block_contrast(uint8_t *src, int x, int y, int stride, int blocksize)
     for (i = 0; i <= blocksize * 2; i++) {
         // We use a width of 16 here to match the sad function
         for (j = 0; j <= 15; j++) {
-            pos = (y - i) * stride + (x - j);
-            if (src[pos] < lowest)
-                lowest = src[pos];
-            else if (src[pos] > highest) {
-                highest = src[pos];
+            if (y >= i) {
+                pos = (y - i) * stride + (x - j);
+                if (src[pos] < lowest)
+                    lowest = src[pos];
+                else if (src[pos] > highest) {
+                    highest = src[pos];
+                }
             }
         }
     }
-- 
1.7.1