3  

This regex will find the mp4 URLs:

此regex将找到mp4 url:

(["\']?https?:\/\/[^\/]+(?:\/[^\/]+)*?.mp4\?(&?\w+(=[^&\'"\s]*)?)*)

After that there's some PHP code to replace the URL with the video and source tags. Note that this now captures leading quote characters to determine if the URL is contained in a href="" or src="" link; the code below explicitly checks for that and skips URLs found that start with quote characters. See the second URL in the first example to see how that works.

之后，有一些PHP代码可以用视频和源标记替换URL。注意，它现在捕获了引言字符，以确定URL是否包含在href=""或src="链接中;下面的代码显式地检查它，并跳过以引号字符开头的url。请参见第一个示例中的第二个URL，以了解其工作原理。

Here is the sample code using the URL to parse standalone MP4 URLs from text:

下面是使用URL解析独立MP4 URL的示例代码:

$subject = <<<LABEL
    This is a very nice Video by Artiste So-n-So    https://s...content-available-to-author-only...m.com/t50.2886-16/13229628_1095069080586346_1424116369_n.mp4


        <a href="http://c...content-available-to-author-only...e.com/akndh39/2016/askbdsjdbuu/my-video.mp4?id=28gsbd0mu&d=33hfsbb">
        Download Video</a>"
LABEL;

$subject = <<<LABEL
Please one more thing, can you expand your regex to include URLs like these.
https://z-1-scontent-lhr3-1.xx.fbcdn.net/v/t42.1790-4/13226507_264732453878764_‌​308543824_n.mp4?efg=eyJ2ZW5jb2RlX3RhZyI6InN2ZV9zZCJ9&oh=c68eadae7d9a5b25ad290ea72‌​3f8fc40&oe=57378FA2 
that is URLs that doesn't end immediately with the extension, but have other parameters added to it.
LABEL;

$pattern = '(["\']?https?:\/\/[^\/]+(?:\/[^\/]+)*?.mp4\?(&?\w+(=[^&\'"\s]*)?)*)';
$matches = Array();
$match = preg_match($pattern, $subject, $matches);

if (count($matches) !== 0) {
    $first_char = substr($matches[0], 0, 1);
    if ($first_cahr !== '"' && $first_char !== "'") {
        $replace = '<video width="320" height="240" controls><source src="' . $matches[0] . '" type="video/mp4"></video>';

        $result = str_replace($matches[0], $replace, $subject);

        print_r($result);
    }
}

The output for the first test case is:

第一个测试用例的输出是:

Success time: 0.03 memory: 52480 signal:0
    This is a very nice Video by Artiste So-n-So    <video width="320" height="240" controls><source src="https://scontent.cdninstagram.com/t50.2886-16/13229628_1095069080586346_1424116369_n.mp4" type="video/mp4"></video>


        <a href="http://cdn.example.com/akndh39/2016/askbdsjdbuu/my-video.mp4?id=28gsbd0mu&d=33hfsbb">
        Download Video</a>"

The output for the second test case is:

第二个测试用例的输出是:

Please one more thing, can you expand your regex to include URLs like these.
<video width="320" height="240" controls><source src="https://z-1-scontent-lhr3-1.xx.fbcdn.net/v/t42.1790-4/13226507_264732453878764_‌​308543824_n.mp4?efg=eyJ2ZW5jb2RlX3RhZyI6InN2ZV9zZCJ9&oh=c68eadae7d9a5b25ad290ea72‌​3f8fc40&oe=57378FA2" type="video/mp4"></video> 
that is URLs that doesn't end immediately with the extension, but have other parameters added to it.