使用php从嵌入代码生成youtube缩略图

Question

I have tried to strip the code below

<iframe width="560" height="315" src="//www.youtube.com/embed/QUVdnzC19oU" frameborder="0" allowfullscreen></iframe>

its working but not stripping the links properly all i get is

http://img.youtube.com/vi/www.youtube.comembedQUVdnzC19oU/0.jpg 

instead of

http://img.youtube.com/vi/QUVdnzC19oU/0.jpg

Please find the php code below.

if(preg_match_all('@<iframe\s[^>]*src=[\"|\']([^\"\'\>]+)[^>].*?</iframe>@siu', $item->introtext, $iframesrc) >0){
            if(isset($iframesrc[1])){
                $vid = str_replace(
                    array(
                        'http://youtu.be/',
                        'http://www.youtube.com/embed/',
                        'http://youtube.googleapis.com/v/'), '', $iframesrc[1][0]);

                $vid = preg_replace('@\/.*?@i', '', $vid);

                if(!(empty($vid))){
                    $result = '' . 
                        '<div class="vimage">
                            <a class="video-link vlink" href="'.$item->link.'" title="">
                                <img src="http://img.youtube.com/vi/'.$vid.'/0.jpg" />
                                <span class="play-icon">&nbsp;</span>
                            </a>
                        </div>';

                    $item->introtext = str_replace($iframesrc['0'], '', $item->introtext);
                }
            }
        }

Thanks in advance.

Answer 1

Replace

array(
    'http://youtu.be/',
    'http://www.youtube.com/embed/',
    'http://youtube.googleapis.com/v/'), '', $iframesrc[1][0]);

by

array(
    '//youtu.be/',
    '//www.youtube.com/embed/',
    '//youtube.googleapis.com/v/',
    'http:', 'https:'), '', $iframesrc[1][0]);

The problem is that you URL das not start with http:// as your code expects. My solution will work with //, http:// and https://.

Also the following line is not useful, as it will never have any effect.

$vid = preg_replace('@\/.*?@i', '', $vid);