[FFmpeg-cvslog] vp56: Check for missing reference frame data

[Laurent Aimar]

ffmpeg | branch: release/0.8 | Laurent Aimar <fenrir at videolan.org> | Wed Sep 21 20:46:30 2011 +0200| [efe3fb13a79957ea94f2766c3f3e502ae775eace] | committer: Reinhard Tartler

vp56: Check for missing reference frame data

Signed-off-by: Janne Grunau <janne-libav at jannau.net>
(cherry picked from commit 0ec6d6e9b682318b5b5b5457e09fbf3c4ca41335)

Signed-off-by: Anton Khirnov <anton at khirnov.net>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=efe3fb13a79957ea94f2766c3f3e502ae775eace
---

 libavcodec/vp56.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/libavcodec/vp56.c b/libavcodec/vp56.c
index a6b2014..4fd1341 100644
--- a/libavcodec/vp56.c
+++ b/libavcodec/vp56.c
@@ -399,6 +399,8 @@ static void vp56_decode_mb(VP56Context *s, int row, int col, int is_alpha)
 
     frame_current = s->framep[VP56_FRAME_CURRENT];
     frame_ref = s->framep[ref_frame];
+    if (mb_type != VP56_MB_INTRA && !frame_ref->data[0])
+        return;
 
     ab = 6*is_alpha;
     b_max = 6 - 2*is_alpha;