织梦视频播放页面用PHP判断用户端是移动端还是PC端

{dede:php}
if (isset ($_SERVER['HTTP_USER_AGENT'])) {
  $clientkeywords = array ('nokia',  'sony','ericsson','mot','samsung','htc','sgh','lg','sharp','oppo','sie-','philips','panasonic'
  ,'alcatel','lenovo','iphone','ipod','blackberry','meizu','android','netfront','symbian','ucweb','windowsce','palm','operamini','operamobi','openwave','nexusone','cldc','midp','wap','mobile'); 
 // 从HTTP_USER_AGENT中查找手机浏览器的关键字
 if (preg_match("/(" . implode('|', $clientkeywords) . ")/i", strtolower($_SERVER['HTTP_USER_AGENT']))){
  echo "
移动端播放器代码
<video width="100%" height="400" controls>
<source src="/视频.mp4" type="video/mp4">
</video>
";
}else{
echo "PC端播放器代码（省略）";
}
}else{
echo "未知";
}
{/dede:php}