protected function faststart($src) {
    if (!$this->config['qt-faststart.bin']) {
      return 0;
    }
    $output = array();
    $dst = $src . '.mp4';
    $result = $this->Process->run($this->config['qt-faststart.bin'], array($src, $dst), $output);
    if ($result == 0) {
      unlink($src);
      rename($dst, $src);
    }
    return $result;
  }