是否可以调整摘录以显示文本or 一张图片or 一个视频？

下面的代码可以显示以上所有内容，但我真的想限制它，这取决于帖子中包含的内容。。

<?php 
function improved_trim_excerpt($text) {
        global $post;
        if ( \'\' == $text ) {
                $text = get_the_content(\'\');
                $text = apply_filters(\'the_content\', $text);
                $text = str_replace(\'\\]\\]\\>\', \']]&gt;\', $text);
                $text = preg_replace(\'@<script[^>]*?>.*?</script>@si\', \'\', $text);
                $text = strip_tags($text, \'<iframe>, <p>, <img>\');
                $excerpt_length = 66;
                $words = explode(\' \', $text, $excerpt_length + 1);
                if (count($words)> $excerpt_length) {
                        array_pop($words);
                        array_push($words, \'[...]\');
                        $text = implode(\' \', $words);
                }
        }
        return $text;
}
?>
<?php
remove_filter(\'get_the_excerpt\', \'wp_trim_excerpt\');
add_filter(\'get_the_excerpt\', \'improved_trim_excerpt\');
?>