<?php

function get_youtube_id($url) {
    // Here is a sample of the URLs this regex matches: (there can be more content after the given URL that will be ignored)
    // http://youtu.be/dQw4w9WgXcQ
    // http://www.youtube.com/embed/dQw4w9WgXcQ
    // http://www.youtube.com/watch?v=dQw4w9WgXcQ
    // http://www.youtube.com/?v=dQw4w9WgXcQ
    // http://www.youtube.com/v/dQw4w9WgXcQ
    // http://www.youtube.com/e/dQw4w9WgXcQ
    // http://www.youtube.com/user/username#p/u/11/dQw4w9WgXcQ
    // http://www.youtube.com/sandalsResorts#p/c/54B8C800269D7C1B/0/dQw4w9WgXcQ
    // http://www.youtube.com/watch?feature=player_embedded&v=dQw4w9WgXcQ
    // http://www.youtube.com/?feature=player_embedded&v=dQw4w9WgXcQ
    // It also works on the youtube-nocookie.com URL with the same above options.
    // It will also pull the ID from the URL in an embed code (both iframe and object tags)
    $youtube_id = '';
    preg_match('%(?:youtube(?:-nocookie)?\.com/(?:[^/]+/.+/|(?:v|e(?:mbed)?)/|.*[?&]v=)|youtu\.be/)([^"&?/ ]{11})%i', $url, $match);
    $youtube_id = trim($match[1]);

    return $youtube_id;
}