public function load_pdf($filename) {
        raise_memory_limit(MEMORY_EXTRA);
        $olddebug = error_reporting(0);

        $this->setPageUnit('pt');
        $this->scale = 72.0 / 100.0;
        $this->SetFont($this->get_export_font_name(), '', 16.0 * $this->scale, '', true);
        $this->SetFillColor(255, 255, 176);
        $this->SetDrawColor(0, 0, 0);
        $this->SetLineWidth(1.0 * $this->scale);
        $this->SetTextColor(0, 0, 0);
        $this->setPrintHeader(false);
        $this->setPrintFooter(false);
        $this->pagecount = $this->setSourceFile($filename);
        $this->filename = $filename;

        error_reporting($olddebug);
        return $this->pagecount;
    }