check if frame size matches old sys and assumes corrupted input, fixes #1192

Originally committed as revision 19192 to svn://svn.ffmpeg.org/ffmpeg/trunk

2 files changed, 8 insertions, 2 deletions

diff --git a/libavcodec/dv.c b/libavcodec/dv.c
index d47929867f..7bc04789f9 100644
--- a/libavcodec/dv.c
+++ b/libavcodec/dv.c
@@ -1119,7 +1119,7 @@ static int dvvideo_decode_frame(AVCodecContext *avctx,
     int buf_size = avpkt->size;
     DVVideoContext *s = avctx->priv_data;
 
-    s->sys = dv_frame_profile(buf);
+    s->sys = dv_frame_profile(s->sys, buf, buf_size);
     if (!s->sys || buf_size < s->sys->frame_size || dv_init_dynamic_tables(s->sys))
         return -1; /* NOTE: we only accept several full frames */
 
diff --git a/libavcodec/dvdata.h b/libavcodec/dvdata.h
index 21023cfe59..a32b863c5d 100644
--- a/libavcodec/dvdata.h
+++ b/libavcodec/dvdata.h
@@ -698,7 +698,9 @@ enum dv_pack_type {
  */
 #define DV_MAX_BPM 8
 
-static inline const DVprofile* dv_frame_profile(const uint8_t* frame)
+static inline
+const DVprofile* dv_frame_profile(const DVprofile *sys,
+                                  const uint8_t* frame, unsigned buf_size)
 {
    int i;
 
@@ -715,6 +717,10 @@ static inline const DVprofile* dv_frame_profile(const uint8_t* frame)
        if (dsf == dv_profiles[i].dsf && stype == dv_profiles[i].video_stype)
            return &dv_profiles[i];
 
+   /* check if old sys matches and assumes corrupted input */
+   if (sys && buf_size == sys->frame_size)
+       return sys;
+
    return NULL;
 }