youtubevideodownloader

class YouTubeDownloader {
    /*
     * Video Id for the given url
     */
    private $video_id;
     
    /*
     * Video title for the given video
     */
    private $video_title;
     
    /*
     * Full URL of the video
     */
    private $video_url;
    
    /*
     * store the url pattern and corresponding downloader object
     * @var array
     */
    private $link_pattern;
    
    public function __construct(){
        $this->link_pattern = "/^(?:http(?:s)?:\/\/)?(?:www\.)?(?:m\.)?(?:youtu\.be\/|youtube\.com\/(?:(?:watch)?\?(?:.*&)?v(?:i)?=|(?:embed)\/))([^\?&\"'>]+)/";
    }
    
    /*
     * Set the url
     * @param string
     */
    public function setUrl($url){
        $this->video_url = $url;
    }
    
    /*
     * Get the video information
     * return string
     */
    private function getVideoInfo(){
        return file_get_contents("https://www.youtube.com/get_video_info?video_id=".$this->extractVideoId($this->video_url)."&cpn=CouQulsSRICzWn5E&eurl&el=adunit");
    }
     
    /*
     * Get video Id
     * @param string
     * return string
     */
    private function extractVideoId($video_url){
        //parse the url
        $parsed_url = parse_url($video_url);
        if($parsed_url["path"] == "youtube.com/watch"){
            $this->video_url = "https://www.".$video_url;
        }elseif($parsed_url["path"] == "www.youtube.com/watch"){
            $this->video_url = "https://".$video_url;
        }
        
        if(isset($parsed_url["query"])){
            $query_string = $parsed_url["query"];
            //parse the string separated by '&' to array
            parse_str($query_string, $query_arr);
            if(isset($query_arr["v"])){
                return $query_arr["v"];
            }
        }   
    }
    
    /*
     * Get the downloader object if pattern matches else return false
     * @param string
     * return object or bool
     * 
     */
    public function getDownloader($url){
        /*
         * check the pattern match with the given video url
         */
        if(preg_match($this->link_pattern, $url)){
            return $this;
        }
        return false;
    }
     
    /*
     * Get the video download link
     * return array
     */
    public function getVideoDownloadLink(){
        //parse the string separated by '&' to array
        parse_str($this->getVideoInfo(), $data);
         
        //set video title
        $this->video_title = $data["title"];
         
        //Get the youtube root link that contains video information
        $stream_map_arr = $this->getStreamArray();
        $final_stream_map_arr = array();
         
        //Create array containing the detail of video 
        foreach($stream_map_arr as $stream){
            parse_str($stream, $stream_data);
            $stream_data["title"] = $this->video_title;
            $stream_data["mime"] = $stream_data["type"];
            $mime_type = explode(";", $stream_data["mime"]);
            $stream_data["mime"] = $mime_type[0];
            $start = stripos($mime_type[0], "/");
            $format = ltrim(substr($mime_type[0], $start), "/");
            $stream_data["format"] = $format;
            unset($stream_data["type"]);
            $final_stream_map_arr [] = $stream_data;         
        }
        return $final_stream_map_arr;
    }
     
    /*
     * Get the youtube root data that contains the video information
     * return array
     */
    private function getStreamArray(){
        parse_str($this->getVideoInfo(), $data);
        $stream_link = $data["url_encoded_fmt_stream_map"];
        return explode(",", $stream_link); 
    }
     
    /*
     * Validate the given video url
     * return bool
     */
    public function hasVideo(){
        $valid = true;
        parse_str($this->getVideoInfo(), $data);
        if($data["status"] == "fail"){
            $valid = false;
        } 
        return $valid;
    }
     
}




// Load and initialize downloader class
include_once 'YouTubeDownloader.class.php';
$handler = new YouTubeDownloader();

// Youtube video url
$youtubeURL = 'https://www.youtube.com/watch?v=zxlR20V4NFQ';

// Check whether the url is valid
if(!empty($youtubeURL) && !filter_var($youtubeURL, FILTER_VALIDATE_URL) === false){
    // Get the downloader object
    $downloader = $handler->getDownloader($youtubeURL);
    
    // Set the url
    $downloader->setUrl($youtubeURL);
    
    // Validate the youtube video url
    if($downloader->hasVideo()){
        // Get the video download link info
        $videoDownloadLink = $downloader->getVideoDownloadLink();
        
        $videoTitle = $videoDownloadLink[0]['title'];
        $videoQuality = $videoDownloadLink[0]['quality'];
        $videoFormat = $videoDownloadLink[0]['format'];
        $videoFileName = strtolower(str_replace(' ', '_', $videoTitle)).'.'.$videoFormat;
        $downloadURL = $videoDownloadLink[0]['url'];
        
        // 
        $fileName = preg_replace('/[^A-Za-z0-9.\_\-]/', '', basename($videoFileName));
        if(!empty($downloadURL)){
            // Define headers
            header("Cache-Control: public");
            header("Content-Description: File Transfer");
            header("Content-Disposition: attachment; filename=$fileName");
            header("Content-Type: application/zip");
            header("Content-Transfer-Encoding: binary");
            
            // Read the file
            readfile($downloadURL);
        }
    }else{
        echo "The video is not found, please check YouTube URL.";
    }
}else{
    echo "Please provide valid YouTube URL.";
}
?>

YouTube Video Downloader Class (YouTubeDownloader.class.php)
The YouTubeDownloader class recovers video information and record URL from YouTube utilizing PHP. This class utilized the accompanying aide techniques to get the YouTube video download link.

setUrl() – Set the video file URL.
getVideoInfo() – Get the video information.
extractVideoId() – Get video Id from YouTube video URL.
getDownloader() – Get the downloader object if example coordinates generally return false.
getVideoDownloadLink() – Get the video download URL with video data (itag, quality, title, mime, and format).
getStreamArray() – Get the youtube root data that contains the video information.
hasVideo() – Validate the YouTube video URL.