function py_mimetype($location, $element_info)
{
  if ( empty( $element_info['tn_ext'] ) )
  {
    global $py_addext;
    $extension = strtolower(get_extension($element_info['path']));
    if (in_array($extension, $py_addext))
    {
      $location= 'plugins/' . GVIDEO_DIR . '/mimetypes/' . $extension . '.png';
    }
  }
  return $location;
}
add_event_handler('get_thumbnail_location', 'py_mimetype', 60, 2);