PHP - Check if audio file is not corrupted

Question

This is method for creating song object

public function getSong() {
        return new Song($this->rackDir, $this->getLoadedDisc()->getName(), $this->song);
    }

There is Song class

class Song extends CD {
    private $id;

    public function __construct($rack, $name, $id)
    {
        $this->id = $id;
        parent::__construct($rack, $name);

    }

    public function getSelectedSongId() {
        return $this->id;
    }

    public function getSelectedSongPath() {
        $list = $this->getSongsList();

        return $list[$this->id];
        }
    }

    public function getSongInfo () {
        $data = [
            'name' => $this->getName(),
            'size' => $this->getSize(),
        ];

        return $data;
    }

    public function getSize() {
        $path = $this->getPath() . '/' . $this->getName();

        return filesize($path);
    }

    public function getName() {
        return $this->getSelectedSongPath();
    }

}

And there is CD Class where I check if file has audio extension.

class CD {
    private $path;
    private $name;
    private $rack;
    private $validExtensions;

    public function __construct($rack, $name)
    {
        $this->rack = $rack . '/';
        $this->name = $name;
        $this->path = $this->rack . $this->name;
        $this->validExtensions = ['mp3', 'mp4', 'wav'];
    }

    public function getPath() {
        return $this->path;
    }

    public function getName() {
        return $this->name;
    }

    public function getSongsList () {
        $path = $this->rack . $this->name;
        $songsList = [];

        if (!is_dir($path)) {
            return false;
        }
        if ($handle = opendir($path)) {
            while (false !== ($file = readdir($handle)))
            {
                if ($file != "." && $file != ".." && in_array(strtolower(substr($file, strrpos($file, '.') + 1)), $this->validExtensions))
                {
                    array_push($songsList, $file);
                }
            }
            closedir($handle);
        }

        return $songsList;
    }
}

I want to check if File is real audio file and not just file with an audio extension? Is there is method to do that in PHP?

Answer 1

Karlos was in right. I was found a solution with this code bellow.

public function validateFile (Song $song) {
    $allowed = array(
        'audio/mp4', 'audio/mp3', 'audio/mpeg3', 'audio/x-mpeg-3', 'audio/mpeg', 'audio/*'
    );

    $finfo = finfo_open(FILEINFO_MIME_TYPE);
    $info = finfo_file($finfo, $song->getSelectedSongPath());

    if (!in_array($info, $allowed)) {
        die( 'file is empty / corrupted');
    }
    return $song;
}