func: static int movie_request_frame(AVFilterLink *outlink)
  
  {
  
      AVFilterBufferRef *outpicref;
  
      MovieContext *movie = outlink->src->priv;
  
      int ret;
  
  
  
      if (movie->is_done)
  
          return AVERROR_EOF;
  
      if ((ret = movie_get_frame(outlink)) < 0)
  
          return ret;
  
  
  
      outpicref = avfilter_ref_buffer(movie->picref, ~0);
  
      ff_start_frame(outlink, outpicref);
  
      ff_draw_slice(outlink, 0, outlink->h, 1);
  
      ff_end_frame(outlink);
  
      avfilter_unref_buffer(movie->picref);
  
      movie->picref = NULL;
  
  
  
      return 0;
  
  }
  