lavf/qsv: clone the frame which may be managed by framework

For filters based on framesync, the input frame was managed
by framesync, so we should not directly keep and destroy it,
instead we make a clone of it here, or else double-free will occur.
But for other filters not based on framesync, we still need to
free the input frame inside filter_frame.

Signed-off-by: Ruiling Song <ruiling.song@intel.com>
(cherry picked from commit d865783b6c)

libavfilter/qsvvpp.c

@@ -296,7 +296,7 @@ static QSVFrame *submit_frame(QSVVPPContext *s, AVFilterLink *inlink, AVFrame *p
             av_log(ctx, AV_LOG_ERROR, "QSVVPP gets a wrong frame.\n");
             return NULL;
         }
-        qsv_frame->frame   = picref;
+        qsv_frame->frame   = av_frame_clone(picref);
         qsv_frame->surface = (mfxFrameSurface1 *)qsv_frame->frame->data[3];
     } else {
         /* make a copy if the input is not padded as libmfx requires */
@@ -318,7 +318,7 @@ static QSVFrame *submit_frame(QSVVPPContext *s, AVFilterLink *inlink, AVFrame *p
             av_frame_copy_props(qsv_frame->frame, picref);
             av_frame_free(&picref);
         } else
-            qsv_frame->frame = picref;
+            qsv_frame->frame = av_frame_clone(picref);
 
         if (map_frame_to_surface(qsv_frame->frame,
                                 &qsv_frame->surface_internal) < 0) {

libavfilter/vf_vpp_qsv.c

@@ -341,9 +341,10 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *picref)
     VPPContext       *vpp = inlink->dst->priv;
     AVFilterLink     *outlink = ctx->outputs[0];
 
-    if (vpp->qsv)
+    if (vpp->qsv) {
         ret = ff_qsvvpp_filter_frame(vpp->qsv, inlink, picref);
-    else {
+        av_frame_free(&picref);
+    } else {
         if (picref->pts != AV_NOPTS_VALUE)
             picref->pts = av_rescale_q(picref->pts, inlink->time_base, outlink->time_base);
         ret = ff_filter_frame(outlink, picref);