avcodec/diracdec: fix undefined behavior with shifts

Fixes part of Ticket3466 Found-by: Andrey_Karpov / PVS-Studio Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
11 years ago · b8598f6ce6
parent ff6fa0b4b9
commit b8598f6ce6
1 changed files with 2 additions and 2 deletions
--- a/libavcodec/diracdec.c
+++ b/libavcodec/diracdec.c
@ -1355,8 +1355,8 @@ static int mc_subpel(DiracContext *s, DiracBlock *block, const uint8_t *src[5],
        motion_y >>= s->chroma_y_shift;
    }

-    mx         = motion_x & ~(-1 << s->mv_precision);
-    my         = motion_y & ~(-1 << s->mv_precision);
+    mx         = motion_x & ~(-1U << s->mv_precision);
+    my         = motion_y & ~(-1U << s->mv_precision);
    motion_x >>= s->mv_precision;
    motion_y >>= s->mv_precision;
    /* normalize subpel coordinates to epel */