Videojs Download Button

The Nuevo plugin features an option to show the Download Button, by default set to false. However, the button does not allow you to download video file directly through JavaScript. Clicking the button triggers the downloadVideo event with two parameters: the current source URL and video_id (if defined). This allows you to use the server-side language function and force downloading video based on the video URL or video_id. Using server-side language, it is possible to download video hosted on the server, fetch video from another server, or even convert the m3u8 source to mp4 online and offer it to download.

The browser does not allow the user to download mp4 or webm video file from a simple link. Instead, it opens a video player in a new card. JavaScript cannot open and download video from a relative path to a media file. JavaScript is a client-side language; it cannot download or fetch video from a server and cannot use tools like ffmpeg to combine media segments of an HLS or MPEG-DASH stream.
One of the methods to force file downloading in JavaScript is to use XMLHttpRequest and generate a blob file-like object. However, this is possible for files hosted on the same server only. Also, such a method is fine for relatively small files. It takes ages to create a blob object from a big video file.
In the example above, we send downloadVideo event parameters to a simple PHP file with a function to force video download immediately from our server.
To enable the downloadButton, simply enable the appropriate Nuevo plugin's option.

Code snippet

<script>
const player = videojs('my_player',{license: "key"}});
player.nuevo({ video_id:"v1234", downloadButton:true });
</script>

And here's how you can catch the downloadVideo event with the current video source parameters. Depending on your preferences, you can send the video ID or video url to a server-side file with a function to force video download.

Code snippet

<script>
player.on('downloadVideo', function(event,data){
video_url = data.source;
video_id = data.id;
//send file to server-side file with download function 
});
</script>

You can't use AJAX to download files. When using the most popular server scripting PHP language, the simplest way is to open a PHP file with a data request.

Code snippet

<script>
window.location(download.php?url=video_url);
or
window.location(download.php?video_id=video_id);
</script>

In a PHP script, you can get a video URL or video ID. If this is mp4 or webm file stored on other than production server, you can use CURL to read and save the file.

Code snippet

<?php
$video_url   = trim($_GET['url']);

header('Content-Description: File Transfer');
header('Content-Type: application/octet-stream');
header('Content-Disposition: attachment; filename='.basename($file));
header('Content-Transfer-Encoding: chunked');
header('Expires: 0');
header('Cache-Control: must-revalidate, post-check=0, pre-check=0');
header('Pragma: public');
$stream = fopen('php://output', 'w');
$ch = curl_init($file);
curl_setopt($ch, CURLOPT_READFUNCTION, function($ch, $fd, $length) use ($stream) {
return fwrite($stream, fread($fd, $length));});
?>

If this is a file hosted on the same server, you need to find the relative path to the video file on your server based on the source URL or video ID. Once you know the video's relative path, check if a file exists and send it to download.

Code snippet

<?php
$video_url   = trim($_GET['url']);
$video_id   = trim($_GET['id']);

// your code to get relative file path of video, based on video url or based on video_id and information stored in database for example.
// the result store in $filepath variable

if (file_exists($filepath) && is_file($filepath) && is_readable($filepath)) {
ini_set('memory_limit', '-1');
@ob_end_clean();
if(ini_get('zlib.output_compression')) {
ini_set('zlib.output_compression', 'Off');
}
header('Content-Type: application/force-download');
header('Content-Disposition: attachment; filename="'.basename($file).'"');
header('Content-Transfer-Encoding: binary');
header('Accept-Ranges: bytes');
header('Cache-control: private');
header('Pragma: private');
header('Expires: Mon, 26 Jul 1997 05:00:00 GMT');
header('Content-Length: ' .filesize($file)); 
readfile($file);
exit();
}
die();
?>

If the video source is an m3u8 or mpd playlist file, a server-side language like PHP allows you to make use of the ffmpeg tool to combine HLS .ts chunk files into an mp4 file and offer it to download.
The PHP code examples above are for illustrative purposes only. The User or User's company must adopt it or write its own download function according to server settings, file storage system, database, etc. PHP is not the only option to prepare the download function, though it's certainly the most popular server-side language.