Convert and generate URL of WebVTT from .srt subtitle file on the fly over Browser/HTML5 environment

HTMLMediaElement/Video doesn't support .srt (SubRip Track) format subtitle as its <track> source - in order to show captions of your video track either you have to convert the SRT file to WebVTT or write it on your own. Because <track src="VALID URL SCHEME"> requires a valid URL of .vtt (Web Video Text Track) formated subtitle track. This library will let you do this on the fly and will give you an URL to set the source of caption track.

Example

https://imshaikot.github.io/srt-webvtt/

Installation

$ npm install srt-webvtt --save

Getting Started

Using it very easy but a little tricky indeed. To getting started:

// Using ES6 es-module
import toWebVTT from "srt-webvtt"; // This is a default export, so you don't have to worry about the import name

// Not using ES6??
var toWebVTT = require("srt-webvtt");

Example and API

When you're using HTMLMediaElement (example: <video>) and you want to show caption on your video player - there's a native HTML Element that will allow us to do that. See the official MDN article and tutorial of this <track> feature

Adding captions and subtitles to HTML5 video

But this feature is limited to WebVTT format and won't allow you to use SRT (very commonly used subtitle)

So, this tiny library will take your .srt subtitle file or a Blob object and will give you converted .vtt file's valid Object URL that you can set as <track>'s source.

See the Example below:

import { default as toWebVTT } from "srt-webvtt";

try {
  const textTrackUrl = await toWebVTT(input.files[0]); // this function accepts a parameer of SRT subtitle blob/file object
  // It is a valid url that can be used as text track URL
  var track = document.getElementById("my-sub-track"); // Track element (which is child of a video element)
  var video = document.getElementById("my-video"); // Main video element
  track.src = textTrackUrl; // Set the converted URL to track's source
  video.textTracks[0].mode = "show"; // Start showing subtitle to your track
} catch (e) {
  console.error(e.message);
}

toWebVTT(file: Blob): Promise<string> and this is it :)

LICENSE

MIT