Add default image for widget

I have a problem to show image gd star rating widget. I use image from content with %image% and working properly but i want show a image if the post no content images. I use

function get_first_image() {
    global $post, $posts;
    $first_img = '';
    ob_start();
    ob_end_clean();
    $output = preg_match_all('/<img.+src=[\'"]([^\'"]+)[\'"].*>/i', $post->post_content, $matches);
    $first_img = $matches [1] [0];

    if(empty($first_img)){ //Defines a default image
        $first_img = "/noimage.jpg";
    }
    return $first_img;
}

in my theme but I do not integrate into template t2, I also edit render.php in line:

if ($widget["image_from"] == "content") {
                    $row->image = gdFunctionsGDSR::get_first_image($row->post_content);
                } else if ($widget["image_from"] == "custom") {
                    $row->image = get_post_meta($row->post_id, $widget["image_custom"], true);
                } else $row->image = "";

But without success.
How I can display a default image if the post no content image?

http://wordpress.org/extend/plugins/gd-star-rating/