diff --git a/libavcodec/h264.c b/libavcodec/h264.c
index dec428965b..2e7204d933 100644
--- a/libavcodec/h264.c
+++ b/libavcodec/h264.c
@@ -2685,8 +2685,9 @@ static void flush_dpb(AVCodecContext *avctx)
 
     flush_change(h);
 
-    for (i = 0; i < MAX_PICTURE_COUNT; i++)
-        unref_picture(h, &h->DPB[i]);
+    if (h->DPB)
+        for (i = 0; i < MAX_PICTURE_COUNT; i++)
+            unref_picture(h, &h->DPB[i]);
     h->cur_pic_ptr = NULL;
     unref_picture(h, &h->cur_pic);
 
diff --git a/libavfilter/vf_gradfun.c b/libavfilter/vf_gradfun.c
index c749534ad9..9e377614ae 100644
--- a/libavfilter/vf_gradfun.c
+++ b/libavfilter/vf_gradfun.c
@@ -202,12 +202,13 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *in)
     GradFunContext *gf = inlink->dst->priv;
     AVFilterLink *outlink = inlink->dst->outputs[0];
     AVFrame *out;
-    int p, direct = 0;
+    int p, direct;
 
     if (av_frame_is_writable(in)) {
         direct = 1;
         out = in;
     } else {
+        direct = 0;
         out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
         if (!out) {
             av_frame_free(&in);
diff --git a/libavfilter/vf_hqdn3d.c b/libavfilter/vf_hqdn3d.c
index 5274956d8d..5b6800c893 100644
--- a/libavfilter/vf_hqdn3d.c
+++ b/libavfilter/vf_hqdn3d.c
@@ -310,12 +310,13 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *in)
     AVFilterLink *outlink = inlink->dst->outputs[0];
 
     AVFrame *out;
-    int direct = 0, c;
+    int direct, c;
 
     if (av_frame_is_writable(in)) {
         direct = 1;
         out = in;
     } else {
+        direct = 0;
         out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
         if (!out) {
             av_frame_free(&in);