也许您应该添加一个自定义字段来接受url本身，而不是wp\\U编辑器文本区域；然后在处理输入后附加嵌入的视频。

如果你需要任何帮助，请告诉我。

或：

您可以添加一个单独的textarea，只接受逗号分隔或换行分隔的URL（因为您在下面声明可能需要多个视频嵌入）

以下是一些保存时使用的代码，这些代码将清理textarea输入：

if ( isset( $_REQUEST[\'your_url_list\'] ) ):


    $input = $_REQUEST[\'your_url_list\'];

    $data = preg_split("/[\\r\\n,]+/", $input, -1, PREG_SPLIT_NO_EMPTY);
    $option_list = array();
    foreach( $data as $d )
        $option_list[] =  trim( $d );

    update_post_meta( $post_id, \'your_url_list\', maybe_serialize( $option_list ) );

endif;

由于您的问题是从HTML内容中查找YouTube URL，以下链接可能会帮助您：https://stackoverflow.com/a/5831191/147618

这里需要从同一链接复制regex。

// Linkify youtube URLs which are not already links.
function linkifyYouTubeURLs($text) {
    $text = preg_replace(\'~
        # Match non-linked youtube URL in the wild. (Rev:20130823)
        https?://         # Required scheme. Either http or https.
        (?:[0-9A-Z-]+\\.)? # Optional subdomain.
        (?:               # Group host alternatives.
          youtu\\.be/      # Either youtu.be,
        | youtube         # or youtube.com or
          (?:-nocookie)?  # youtube-nocookie.com
          \\.com           # followed by
          \\S*             # Allow anything up to VIDEO_ID,
          [^\\w\\s-]       # but char before ID is non-ID char.
        )                 # End host alternatives.
        ([\\w-]{11})      # $1: VIDEO_ID is exactly 11 chars.
        (?=[^\\w-]|$)     # Assert next char is non-ID or EOS.
        (?!               # Assert URL is not pre-linked.
          [?=&+%\\w.-]*    # Allow URL (query) remainder.
          (?:             # Group pre-linked alternatives.
            [\\\'"][^<>]*>  # Either inside a start tag,
          | </a>          # or inside <a> element text contents.
          )               # End recognized pre-linked alts.
        )                 # End negative lookahead assertion.
        [?=&+%\\w.-]*        # Consume any URL (query) remainder.
        ~ix\', 
        \'<a href="http://www.youtube.com/watch?v=$1">YouTube link: $1</a>\',
        $text);
    return $text;
}