avfilter/signalstats: fix different buffers for out frame if burn is enabled

This was the original intend.

diff --git a/libavfilter/vf_signalstats.c b/libavfilter/vf_signalstats.c
index 47545aa080f76815a3399eae2293f73d239d856d..8c6a2d6bbd49bd62961e95d09b0c306d32d2adef 100644 (file)
--- a/libavfilter/vf_signalstats.c
+++ b/libavfilter/vf_signalstats.c
@@ -294,8 +294,10 @@ static int filter_frame(AVFilterLink *link, AVFrame *in)
 
     prev = s->frame_prev;
 
-    if (s->outfilter != FILTER_NONE)
+    if (s->outfilter != FILTER_NONE) {
         out = av_frame_clone(in);
+        av_frame_make_writable(out);
+    }
 
     for (fil = 0; fil < FILT_NUMB; fil ++)
         if ((s->filters & 1<<fil) && filters_def[fil].init)