sws: check that dither array is not null before memset

Fixes null pointer dereference Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
12 years ago · 89afa635bf
parent aef5c0b68f
commit 89afa635bf
1 changed files with 1 additions and 1 deletions
--- a/libswscale/swscale.c
+++ b/libswscale/swscale.c
@ -910,7 +910,7 @@ int attribute_align_arg sws_scale(struct SwsContext *c,
        src2[0] = base;
    }

-    if (!srcSliceY && (c->flags & SWS_BITEXACT) && (c->flags & SWS_ERROR_DIFFUSION))
+    if (!srcSliceY && (c->flags & SWS_BITEXACT) && (c->flags & SWS_ERROR_DIFFUSION) && c->dither_error[0])
        for (i = 0; i < 4; i++)
            memset(c->dither_error[i], 0, sizeof(c->dither_error[0][0]) * (c->dstW+2));