-static void start_frame(AVFilterLink *inlink, AVFilterBufferRef *inpicref)
-{
- AVFilterLink *outlink = inlink->dst->outputs[0];
- AVFilterBufferRef *outpicref;
-
- if (inpicref->perms & AV_PERM_PRESERVE) {
- outpicref = ff_get_video_buffer(outlink, AV_PERM_WRITE, outlink->w, outlink->h);
- avfilter_copy_buffer_ref_props(outpicref, inpicref);
- outpicref->video->w = outlink->w;
- outpicref->video->h = outlink->h;
- } else
- outpicref = inpicref;
-
- outlink->out_buf = outpicref;
- ff_start_frame(outlink, avfilter_ref_buffer(outpicref, ~0));
-}
-
-static void null_draw_slice(AVFilterLink *link, int y, int h, int slice_dir) { }
-
-static void end_frame(AVFilterLink *inlink)