[FFmpeg-cvslog] indeo3: Fix null ptr dereference

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michaelni at gmx.at> | Wed Dec 21 00:35:10 2011 +0100| [134aaa79f7f1ce1df64afc7d10d2b3de77df7b08] | committer: Michael Niedermayer

indeo3: Fix null ptr dereference
Fixes Ticket804
Bug found by: Oana Stratulat

Signed-off-by: Michael Niedermayer <michaelni at gmx.at>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=134aaa79f7f1ce1df64afc7d10d2b3de77df7b08
---

 libavcodec/indeo3.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/libavcodec/indeo3.c b/libavcodec/indeo3.c
index 2c96662..83c97bb 100644
--- a/libavcodec/indeo3.c
+++ b/libavcodec/indeo3.c
@@ -770,7 +770,8 @@ static int parse_bintree(Indeo3DecodeContext *ctx, AVCodecContext *avctx,
                 /* get motion vector index and setup the pointer to the mv set */
                 if (!ctx->need_resync)
                     ctx->next_cell_data = &ctx->gb.buffer[(get_bits_count(&ctx->gb) + 7) >> 3];
-                curr_cell.mv_ptr = &ctx->mc_vectors[*(ctx->next_cell_data++) << 1];
+                if(ctx->mc_vectors)
+                    curr_cell.mv_ptr = &ctx->mc_vectors[*(ctx->next_cell_data++) << 1];
                 curr_cell.tree   = 1; /* enter the VQ tree */
                 UPDATE_BITPOS(8);
             } else { /* VQ tree DATA code */