[FFmpeg-cvslog] h264: More correct ref_count check in decode_slice_header()

[Michael Niedermayer]

ffmpeg | branch: release/0.8 | Michael Niedermayer <michaelni at gmx.at> | Wed Sep 28 22:22:56 2011 +0200| [be9183de2ec54aab2f3e613b53ead369b6cf22fe] | committer: Michael Niedermayer

h264: More correct ref_count check in decode_slice_header()

Signed-off-by: Michael Niedermayer <michaelni at gmx.at>
(cherry picked from commit dc9ce40069bde3d28f8d0b3e5bd733ae255fecb5)

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=be9183de2ec54aab2f3e613b53ead369b6cf22fe
---

 libavcodec/h264.c |   11 ++++++-----
 1 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/libavcodec/h264.c b/libavcodec/h264.c
index f227ddf..b844c38 100644
--- a/libavcodec/h264.c
+++ b/libavcodec/h264.c
@@ -2872,6 +2872,7 @@ static int decode_slice_header(H264Context *h, H264Context *h0){
     h->ref_count[1]= h->pps.ref_count[1];
 
     if(h->slice_type_nos != AV_PICTURE_TYPE_I){
+        unsigned max= (16<<(s->picture_structure != PICT_FRAME))-1;
         if(h->slice_type_nos == AV_PICTURE_TYPE_B){
             h->direct_spatial_mv_pred= get_bits1(&s->gb);
         }
@@ -2882,11 +2883,11 @@ static int decode_slice_header(H264Context *h, H264Context *h0){
             if(h->slice_type_nos==AV_PICTURE_TYPE_B)
                 h->ref_count[1]= get_ue_golomb(&s->gb) + 1;
 
-            if(h->ref_count[0]-1 > 32-1 || h->ref_count[1]-1 > 32-1){
-                av_log(h->s.avctx, AV_LOG_ERROR, "reference overflow\n");
-                h->ref_count[0]= h->ref_count[1]= 1;
-                return -1;
-            }
+        }
+        if(h->ref_count[0]-1 > max || h->ref_count[1]-1 > max){
+            av_log(h->s.avctx, AV_LOG_ERROR, "reference overflow\n");
+            h->ref_count[0]= h->ref_count[1]= 1;
+            return -1;
         }
         if(h->slice_type_nos == AV_PICTURE_TYPE_B)
             h->list_count= 2;