[FFmpeg-cvslog] mpeg4videodec: make sure f/b_code are not invalid values.

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michaelni at gmx.at> | Sat Apr  7 16:39:59 2012 +0200| [6c249392fa646f509823d5ce12d0c2515d8f31f2] | committer: Michael Niedermayer

mpeg4videodec: make sure f/b_code are not invalid values.

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

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=6c249392fa646f509823d5ce12d0c2515d8f31f2
---

 libavcodec/mpeg4videodec.c |    6 ++++++
 1 files changed, 6 insertions(+), 0 deletions(-)

diff --git a/libavcodec/mpeg4videodec.c b/libavcodec/mpeg4videodec.c
index c87af82..99aecbb 100644
--- a/libavcodec/mpeg4videodec.c
+++ b/libavcodec/mpeg4videodec.c
@@ -2073,6 +2073,7 @@ static int decode_vop_header(MpegEncContext *s, GetBitContext *gb){
              s->f_code = get_bits(gb, 3);       /* fcode_for */
              if(s->f_code==0){
                  av_log(s->avctx, AV_LOG_ERROR, "Error, header damaged or not MPEG4 header (f_code=0)\n");
+                 s->f_code=1;
                  return -1; // makes no sense to continue, as the MV decoding will break very quickly
              }
          }else
@@ -2080,6 +2081,11 @@ static int decode_vop_header(MpegEncContext *s, GetBitContext *gb){
 
          if (s->pict_type == AV_PICTURE_TYPE_B) {
              s->b_code = get_bits(gb, 3);
+             if(s->b_code==0){
+                 av_log(s->avctx, AV_LOG_ERROR, "Error, header damaged or not MPEG4 header (b_code=0)\n");
+                 s->b_code=1;
+                 return -1; // makes no sense to continue, as the MV decoding will break very quickly
+             }
          }else
              s->b_code=1;