显示youtube视频缩略图和Vimeo视频缩略图代码分享

function video_image($url){
   $image_url = parse_url($url);
     if($image_url[host] == www.youtube.com ||
        $image_url[host] == youtube.com){
         $array = explode("&", $image_url[query]);
         return "http://img.youtube.com/vi/".substr($array[0], 2)."/0.jpg";
     }else if($image_url[host] == www.youtu.be ||
              $image_url[host] == youtu.be){
         $array = explode("/", $image_url[path]);
         return "http://img.youtube.com/vi/".$array[1]."/0.jpg";
     }else if($image_url[host] == www.vimeo.com ||
         $image_url[host] == vimeo.com){
         $hash = unserialize(file_get_contents("http://vimeo.com/api/v2/video/".
         substr($image_url[path], 1).".php"));
         return $hash[0]["thumbnail_medium"];
     }
}

<img src="<?php echo video_image(youtube URL); ?>" />