[FFmpeg-cvslog] Prevent NULL dereferences when missing the reference frame in the bink decoder .

[Laurent Aimar]

ffmpeg | branch: release/0.8 | Laurent Aimar <fenrir at videolan.org> | Tue Sep 27 20:22:13 2011 +0200| [08decaeb95f20821df993a7c3b1692ce654ad390] | committer: Michael Niedermayer

Prevent NULL dereferences when missing the reference frame in the bink decoder.

Signed-off-by: Michael Niedermayer <michaelni at gmx.at>
(cherry picked from commit 66aae97a60fcd8658f18c484b5af898a48d0e3f9)

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=08decaeb95f20821df993a7c3b1692ce654ad390
---

 libavcodec/bink.c |    8 +++++---
 1 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/libavcodec/bink.c b/libavcodec/bink.c
index f4fa44b..63f17eb 100644
--- a/libavcodec/bink.c
+++ b/libavcodec/bink.c
@@ -973,8 +973,9 @@ static int bink_decode_plane(BinkContext *c, GetBitContext *gb, int plane_idx,
     for (i = 0; i < BINK_NB_SRC; i++)
         read_bundle(gb, c, i);
 
-    ref_start = c->last.data[plane_idx];
-    ref_end   = c->last.data[plane_idx]
+    ref_start = c->last.data[plane_idx] ? c->last.data[plane_idx]
+                                        : c->pic.data[plane_idx];
+    ref_end   = ref_start
                 + (bw - 1 + c->last.linesize[plane_idx] * (bh - 1)) * 8;
 
     for (i = 0; i < 64; i++)
@@ -1003,7 +1004,8 @@ static int bink_decode_plane(BinkContext *c, GetBitContext *gb, int plane_idx,
         if (by == bh)
             break;
         dst  = c->pic.data[plane_idx]  + 8*by*stride;
-        prev = c->last.data[plane_idx] + 8*by*stride;
+        prev = (c->last.data[plane_idx] ? c->last.data[plane_idx]
+                                        : c->pic.data[plane_idx]) + 8*by*stride;
         for (bx = 0; bx < bw; bx++, dst += 8, prev += 8) {
             blk = get_value(c, BINK_SRC_BLOCK_TYPES);
             // 16x16 block type on odd line means part of the already decoded block, so skip it