From a8edc1cbc76f2c8144796f3f984bc4607fb0d71d Mon Sep 17 00:00:00 2001
From: "Ronald S. Bultje" <rsbultje@gmail.com>
Date: Wed, 24 Aug 2011 14:36:16 -0700
Subject: [PATCH] vc1: properly zero coded_block[] edges on new slice entry.

Previously, we would leave the left edge uninitialized, which led to
CBP prediction errors on slice edges, e.g. in SA10098.vc1.
(cherry picked from commit d4b9974465baf893e90527a366e7a7411ded1ef8)

Signed-off-by: Anton Khirnov <anton@khirnov.net>
---
 libavcodec/vc1dec.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavcodec/vc1dec.c b/libavcodec/vc1dec.c
index 8fca2da738..b17ce30b5c 100644
--- a/libavcodec/vc1dec.c
+++ b/libavcodec/vc1dec.c
@@ -3020,7 +3020,7 @@ static void vc1_decode_i_blocks_adv(VC1Context *v)
         s->mb_x = 0;
         ff_init_block_index(s);
         memset(&s->coded_block[s->block_index[0]-s->b8_stride], 0,
-               s->b8_stride * sizeof(*s->coded_block));
+               (1 + s->b8_stride) * sizeof(*s->coded_block));
     }
     for(; s->mb_y < s->end_mb_y; s->mb_y++) {
         s->mb_x = 0;