How can I retrieve YouTube video details from video URL using PHP?

Yet another URL API that can be helpful is: https://www.youtube.com/get_video_info?video_id=B4CRkpBGQzU

video_id is "v" argument of youTube. Result is a dictionary in URL-encoded format (key1=value1&key2=value2&...)

This is undocumented API existing for long time, so exploring it is up to developer. I am aware of "status" (ok/fail), "errorcode" (100 and 150 in my practice), "reason" (string description of error). I am getting duration ("length_seconds") this way because oEmbed does not provide this information (strange, but true) and I can hardly motivate every employer to get keys from youTube to use official API

You can get data from youtube oembed interface in two formats: XML and JSON

Interface address: http://www.youtube.com/oembed?url=youtubeurl&format=json

Use this PHP function to get data

 function get_youtube($url){

 $youtube = "http://www.youtube.com/oembed?url=". $url ."&format=json";

 $curl = curl_init($youtube);
 curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);
 $return = curl_exec($curl);
 curl_close($curl);
 return json_decode($return, true);

 }

$url = // youtube video url 

// Display Data 
print_r(get_youtube($url));

Don't forget to enable extension=php_curl.dll in your php.ini

This returns metadata about a video:

http://www.youtube.com/oembed?url={videoUrlHere}&format=json

Using your example, a call to:

http://www.youtube.com/oembed?url=http://www.youtube.com/watch?v=B4CRkpBGQzU&format=json

Returns the following, which you can digest and parse with PHP:

{
    "provider_url": "http:\/\/www.youtube.com\/",
    "thumbnail_url": "http:\/\/i3.ytimg.com\/vi\/B4CRkpBGQzU\/hqdefault.jpg",
    "title": "Joan Osborne - One Of Us",
    "html": "\u003ciframe width=\"459\" height=\"344\" src=\"http:\/\/www.youtube.com\/embed\/B4CRkpBGQzU?fs=1\u0026feature=oembed\" frameborder=\"0\" allowfullscreen\u003e\u003c\/iframe\u003e",
    "author_name": "jzsdhk",
    "height": 344,
    "thumbnail_width": 480,
    "width": 459,
    "version": "1.0",
    "author_url": "http:\/\/www.youtube.com\/user\/jzsdhk",
    "provider_name": "YouTube",
    "type": "video",
    "thumbnail_height": 360
}

To get youtube video description, different sized thumbnail, tags, etc use updated v3 googleapis

Sample URL: https://www.googleapis.com/youtube/v3/videos?part=snippet&id=7wtfhZwyrcc&key=my_google_api_key

$google_api_key = 'google_api_key';
$video_id = 'youtube_video_id';
$api_url = 'https://www.googleapis.com/youtube/v3/videos?part=snippet&id='.$video_id.'&key='.$google_api_key;
$json = file_get_contents($api_url);
$obj = json_decode($json);
var_dump($obj);