lavfi: unref AVFilterLink.cur_buf in ff_end_frame().

This reduces code duplication and prevents stale pointers from remaining
on the link.

libavfilter/fifo.c

@@ -91,6 +91,7 @@ static int add_to_queue(AVFilterLink *inlink, AVFilterBufferRef *buf)
 static void start_frame(AVFilterLink *inlink, AVFilterBufferRef *buf)
 {
     add_to_queue(inlink, buf);
+    inlink->cur_buf = NULL;
 }
 
 static void queue_pop(FifoContext *s)

libavfilter/split.c

@@ -89,8 +89,6 @@ static void end_frame(AVFilterLink *inlink)
 
     for (i = 0; i < ctx->nb_outputs; i++)
         ff_end_frame(ctx->outputs[i]);
-
-    avfilter_unref_buffer(inlink->cur_buf);
 }
 
 AVFilter avfilter_vf_split = {

libavfilter/vf_crop.c

@@ -317,7 +317,6 @@ static void end_frame(AVFilterLink *link)
     CropContext *crop = link->dst->priv;
 
     crop->var_values[VAR_N] += 1.0;
-    avfilter_unref_buffer(link->cur_buf);
     ff_end_frame(link->dst->outputs[0]);
 }
 

libavfilter/vf_delogo.c

@@ -260,7 +260,6 @@ static void end_frame(AVFilterLink *inlink)
 
     ff_draw_slice(outlink, 0, inlink->h, 1);
     ff_end_frame(outlink);
-    avfilter_unref_buffer(inpicref);
     avfilter_unref_buffer(outpicref);
 }
 

libavfilter/vf_drawtext.c

@@ -868,7 +868,6 @@ static void end_frame(AVFilterLink *inlink)
 
     ff_draw_slice(outlink, 0, picref->video->h, 1);
     ff_end_frame(outlink);
-    avfilter_unref_buffer(inlink->cur_buf);
 }
 
 AVFilter avfilter_vf_drawtext = {

libavfilter/vf_fieldorder.c

@@ -213,7 +213,6 @@ static void end_frame(AVFilterLink *inlink)
     }
 
     ff_end_frame(outlink);
-    avfilter_unref_buffer(inpicref);
     avfilter_unref_bufferp(&outlink->out_buf);
 }
 

libavfilter/vf_fps.c

@@ -175,6 +175,7 @@ static void end_frame(AVFilterLink *inlink)
     int64_t delta;
     int i;
 
+    inlink->cur_buf = NULL;
     s->frames_in++;
     /* discard frames until we get the first timestamp */
     if (s->pts == AV_NOPTS_VALUE) {

libavfilter/vf_frei0r.c

@@ -352,7 +352,6 @@ static void end_frame(AVFilterLink *inlink)
     frei0r->update(frei0r->instance, inpicref->pts * av_q2d(inlink->time_base) * 1000,
                    (const uint32_t *)inpicref->data[0],
                    (uint32_t *)outpicref->data[0]);
-    avfilter_unref_buffer(inpicref);
     ff_draw_slice(outlink, 0, outlink->h, 1);
     ff_end_frame(outlink);
     avfilter_unref_buffer(outpicref);

libavfilter/vf_gradfun.c

@@ -225,7 +225,6 @@ static void end_frame(AVFilterLink *inlink)
 
     ff_draw_slice(outlink, 0, inlink->h, 1);
     ff_end_frame(outlink);
-    avfilter_unref_buffer(inpic);
     avfilter_unref_buffer(outpic);
 }
 

libavfilter/vf_hqdn3d.c

@@ -322,7 +322,6 @@ static void end_frame(AVFilterLink *inlink)
 
     ff_draw_slice(outlink, 0, inpic->video->h, 1);
     ff_end_frame(outlink);
-    avfilter_unref_buffer(inpic);
     avfilter_unref_buffer(outpic);
 }
 

libavfilter/vf_libopencv.c

@@ -365,7 +365,6 @@ static void end_frame(AVFilterLink *inlink)
     ocv->end_frame_filter(ctx, &inimg, &outimg);
     fill_picref_from_iplimage(outpicref, &outimg, inlink->format);
 
-    avfilter_unref_buffer(inpicref);
     ff_draw_slice(outlink, 0, outlink->h, 1);
     ff_end_frame(outlink);
     avfilter_unref_buffer(outpicref);

libavfilter/vf_overlay.c

@@ -339,7 +339,6 @@ static void draw_slice(AVFilterLink *inlink, int y, int h, int slice_dir)
 static void end_frame(AVFilterLink *inlink)
 {
     ff_end_frame(inlink->dst->outputs[0]);
-    avfilter_unref_buffer(inlink->cur_buf);
 }
 
 static void null_draw_slice(AVFilterLink *inlink, int y, int h, int slice_dir) { }

libavfilter/vf_pad.c

@@ -348,7 +348,6 @@ static void end_frame(AVFilterLink *link)
 {
     ff_end_frame(link->dst->outputs[0]);
     avfilter_unref_buffer(link->dst->outputs[0]->out_buf);
-    avfilter_unref_buffer(link->cur_buf);
 }
 
 static void draw_send_bar_slice(AVFilterLink *link, int y, int h, int slice_dir, int before_slice)

libavfilter/vf_select.c

@@ -258,14 +258,12 @@ static void draw_slice(AVFilterLink *inlink, int y, int h, int slice_dir)
 static void end_frame(AVFilterLink *inlink)
 {
     SelectContext *select = inlink->dst->priv;
-    AVFilterBufferRef *picref = inlink->cur_buf;
 
     if (select->select) {
         if (select->cache_frames)
             return;
         ff_end_frame(inlink->dst->outputs[0]);
     }
-    avfilter_unref_buffer(picref);
 }
 
 static int request_frame(AVFilterLink *outlink)

libavfilter/vf_transpose.c

@@ -192,7 +192,6 @@ static void end_frame(AVFilterLink *inlink)
         }
     }
 
-    avfilter_unref_buffer(inpic);
     ff_draw_slice(outlink, 0, outpic->video->h, 1);
     ff_end_frame(outlink);
     avfilter_unref_buffer(outpic);

libavfilter/vf_unsharp.c

@@ -225,7 +225,6 @@ static void end_frame(AVFilterLink *link)
     apply_unsharp(out->data[1], out->linesize[1], in->data[1], in->linesize[1], cw,      ch,      &unsharp->chroma);
     apply_unsharp(out->data[2], out->linesize[2], in->data[2], in->linesize[2], cw,      ch,      &unsharp->chroma);
 
-    avfilter_unref_buffer(in);
     ff_draw_slice(link->dst->outputs[0], 0, link->h, 1);
     ff_end_frame(link->dst->outputs[0]);
     avfilter_unref_buffer(out);

libavfilter/video.c

@@ -162,7 +162,8 @@ AVFilterBufferRef *ff_get_video_buffer(AVFilterLink *link, int perms, int w, int
 
 void ff_null_start_frame(AVFilterLink *link, AVFilterBufferRef *picref)
 {
-    ff_start_frame(link->dst->outputs[0], picref);
+    AVFilterBufferRef *buf_out = avfilter_ref_buffer(picref, ~0);
+    ff_start_frame(link->dst->outputs[0], buf_out);
 }
 
 static void default_start_frame(AVFilterLink *inlink, AVFilterBufferRef *picref)
@@ -223,9 +224,6 @@ static void default_end_frame(AVFilterLink *inlink)
     if (inlink->dst->nb_outputs)
         outlink = inlink->dst->outputs[0];
 
-    avfilter_unref_buffer(inlink->cur_buf);
-    inlink->cur_buf = NULL;
-
     if (outlink) {
         if (outlink->out_buf) {
             avfilter_unref_buffer(outlink->out_buf);
@@ -250,6 +248,7 @@ void ff_end_frame(AVFilterLink *link)
         avfilter_unref_buffer(link->src_buf);
         link->src_buf = NULL;
     }
+    avfilter_unref_bufferp(&link->cur_buf);
 }
 
 void ff_null_draw_slice(AVFilterLink *link, int y, int h, int slice_dir)