[FFmpeg-cvslog] In svq3 decoder, check negative mb_type, fix potential crash.

[Baptiste Coudurier]

ffmpeg | branch: master | Baptiste Coudurier <baptiste.coudurier at gmail.com> | Wed May  4 18:45:36 2011 -0700| [0fa8d19987f03444365a5c7f73b7ecf1520b011e] | committer: Michael Niedermayer

In svq3 decoder, check negative mb_type, fix potential crash.

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

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=0fa8d19987f03444365a5c7f73b7ecf1520b011e
---

 libavcodec/svq3.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/libavcodec/svq3.c b/libavcodec/svq3.c
index 16f4834..7516606 100644
--- a/libavcodec/svq3.c
+++ b/libavcodec/svq3.c
@@ -1049,7 +1049,7 @@ static int svq3_decode_frame(AVCodecContext *avctx,
             } else if (s->pict_type == AV_PICTURE_TYPE_B && mb_type >= 4) {
                 mb_type += 4;
             }
-            if (mb_type > 33 || svq3_decode_mb(svq3, mb_type)) {
+            if ((unsigned)mb_type > 33 || svq3_decode_mb(svq3, mb_type)) {
                 av_log(h->s.avctx, AV_LOG_ERROR, "error while decoding MB %d %d\n", s->mb_x, s->mb_y);
                 return -1;
             }