avcodec/snow: clear freed pointers

Avoid leaving stale pointers in memory

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

1 files changed, 3 insertions, 1 deletions

diff --git a/libavcodec/snow.c b/libavcodec/snow.c
index 3701707787..83db3c7195 100644
--- a/libavcodec/snow.c
+++ b/libavcodec/snow.c
@@ -637,8 +637,10 @@ void ff_snow_release_buffer(AVCodecContext *avctx)
     if(s->last_picture[s->max_ref_frames-1]->data[0]){
         av_frame_unref(s->last_picture[s->max_ref_frames-1]);
         for(i=0; i<9; i++)
-            if(s->halfpel_plane[s->max_ref_frames-1][1+i/3][i%3])
+            if(s->halfpel_plane[s->max_ref_frames-1][1+i/3][i%3]) {
                 av_free(s->halfpel_plane[s->max_ref_frames-1][1+i/3][i%3] - EDGE_WIDTH*(1+s->current_picture->linesize[i%3]));
+                s->halfpel_plane[s->max_ref_frames-1][1+i/3][i%3] = NULL;
+            }
     }
 }