avf_showwaves: fix null pointer dereference

Found-by: durandal_1707
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

diff --git a/libavfilter/avf_showwaves.c b/libavfilter/avf_showwaves.c
index 30a8e1e62fa1af1f93f941087ddc2eb49e1437ee..3e5f39f3c947388f7c757e5a7680dea1431821ac 100644 (file)
--- a/libavfilter/avf_showwaves.c
+++ b/libavfilter/avf_showwaves.c
@@ -220,6 +220,7 @@ static int filter_frame(AVFilterLink *inlink, AVFilterBufferRef *insamples)
         }
         if (showwaves->buf_idx == showwaves->w)
             push_frame(outlink);
+        outpicref = showwaves->outpicref;
     }
 
     avfilter_unref_buffer(insamples);