mpegvideo: fix out of heap array accesses

Signed-off-by: Michael Niedermayer <michaelni@gmx.at> (cherry picked from commit 317ca0d) Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
axmhari · Jun 9, 2012 · 997e769 · 997e769
1 parent 944b6a8
commit 997e769
Showing 1 changed file with 2 additions and 2 deletions.
diff --git a/libavcodec/mpegvideo.c b/libavcodec/mpegvideo.c
@@ -1429,7 +1429,7 @@ static void draw_line(uint8_t *buf, int sx, int sy, int ex, int ey,
             y  = (x * f) >> 16;
             fr = (x * f) & 0xFFFF;
             buf[y * stride + x]       += (color * (0x10000 - fr)) >> 16;
-            buf[(y + 1) * stride + x] += (color *            fr ) >> 16;
+            if(fr) buf[(y + 1) * stride + x] += (color *            fr ) >> 16;
         }
     } else {
         if (sy > ey) {
@@ -1446,7 +1446,7 @@ static void draw_line(uint8_t *buf, int sx, int sy, int ex, int ey,
             x  = (y*f) >> 16;
             fr = (y*f) & 0xFFFF;
             buf[y * stride + x]     += (color * (0x10000 - fr)) >> 16;
-            buf[y * stride + x + 1] += (color *            fr ) >> 16;
+            if(fr) buf[y * stride + x + 1] += (color *            fr ) >> 16;
         }
     }
 }