如何将下载的文件保存到文件夹

I write a parser receiving video.No can`t save the resulting video itself to the desired folder to me. How to fix, here's the code.

foreach ($href as $key => $link) {
    $doc = file_get_html('https://example.com/'.$link);
    foreach($doc->find("#video source") as $el) {
        $video[]="https:".$el->src;   
    }
}
//finally I get
/* array(
    "http:example/video1.mp4",
    "http:example/video2.mp4",
    "http:example/video3.mp4")
 */

$dirSubtitles=$_SERVER['DOCUMENT_ROOT'].'/video/';
foreach ($video as $key=>$address) {
    $url  = $address;
    $path = $dirSubtitles;
    $fp = fopen($path."video".$key, 'w');
    $ch = curl_init($url);
    curl_setopt($ch, CURLOPT_FILE, $fp);
    $data = curl_exec($ch);
    curl_close($ch);
    fclose($fp);
}

You might want to read about file_put_contents()

I hope this will help you in the right direction.