HTML -Track

The <track> HTML element is used as a child of the media elements,
<audio> and <video>. It lets you specify timed text tracks (or time-based data),
for example to automatically handle subtitles. 
e.g.
<video controls
       src="/media/cc0-videos/friday.mp4">
    <track default
           kind="captions"
           srclang="en"
           src="/media/examples/friday.vtt" />
    Sorry, your browser doesn't support embedded videos.
</video>
Literate Lentil