复制代码 代码如下:
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"); ?>" />