subtitle.js


Parse, manipulate and stringify SRT (SubRip) format. WebVTT as input is
also supported.

>"Thanks for this rad package!"
>John-David Dalton, creator of Lodash

Installation

npm install subtitle --save

Usage

``js
// ES2015 modules
import * as Subtitle from 'subtitle'
import { parse, stringify, stringifyVtt, resync, toMS, toSrtTime, toVttTime } from 'subtitle'
`

`js
// ES6 CommonJS
const Subtitle = require('subtitle')
const { parse, stringify, stringifyVtt, resync, toMS, toSrtTime, toVttTime } = require('subtitle')
`

`js
// ES5 CommonJS
var Subtitle = require('subtitle')
Subtitle.parse
Subtitle.stringify
Subtitle.stringifyVtt
Subtitle.resync
Subtitle.toMS
Subtitle.toSrtTime
Subtitle.toVttTime
`

$3

If you don't use a bundler like Webpack or Browserify, you can just copy the
script subtitle.bundle.js from the dist folder and link it to your page.

`html


`

API

The API is minimal and provide only five functions, two of which have SRT and WebVTT variants:

* parse
* stringify
* stringifyVtt
* resync
* toMS
* toSrtTime
* toVttTime

$3

Parses a SRT or WebVTT string and returns an array:

`js
parse(mySrtOrVttContent)
[
{
start: 20000, // time in ms
end: 24400,
text: 'Bla Bla Bla Bla'
},
{
start: 24600,
end: 27800,
text: 'Bla Bla Bla Bla',
settings: 'align:middle line:90%' // WebVTT only
}
]
`

$3

The reverse of parse. It gets an array with subtitles and converts it to a valid SRT string.

The stringifyVtt(captions: Array) -> String function is also available for converting to a
valid WebVTT string.

`js
const subtitles = [
{
start: '00:00:20,000',
end: '00:00:24,400',
text: 'Bla Bla Bla Bla'
},
{
start: 24600, // timestamp in milliseconds is supported as well
end: 27800,
text: 'Bla Bla Bla Bla',
settings: 'align:middle line:90%' // Ignored in SRT format
}
]

const srt = stringify(subtitles)
// returns the following string:
/*
1
00:00:20,000 --> 00:00:24,400
Bla Bla Bla Bla

2
00:00:24,600 --> 00:00:27,800
Bla Bla Bla Bla
*/

const vtt = stringifyVtt(subtitles)
// returns the following string:
/*
WEBVTT

1
00:00:20.000 --> 00:00:24.400
Bla Bla Bla Bla

2
00:00:24.600 --> 00:00:27.800 align:middle line:90%
Bla Bla Bla Bla
*/
`

$3

Resync all captions at once.

`js
const subtitles = [
{
start: '00:00:20,000',
end: '00:00:24,400',
text: 'Bla Bla Bla Bla'
},
{
start: 24600, // timestamp in millseconds is supported as well
end: 27800,
text: 'Bla Bla Bla Bla'
}
]

// Advance 1s
const newSubtitles = resync(subtitles, 1000)

// Delay 250ms
const newSubtitles = resync(subtitles, -250) //

// Then, you can stringify your new subtitles:
stringify(newSubtitles)
`

$3

Convert a SRT or WebVTT timestamp to milliseconds:

`js
toMS('00:00:24,400')
// 24400

toMS('00:24.400')
// 24400
`

$3

Convert a time from milliseconds to a SRT timestamp:

`js
toSrtTime(24400)
// '00:00:24,400'
`

$3

Convert a time from milliseconds to a WebVTT timestamp:

`js
toVttTime(24400)
// '00:00:24.400'
`

Tests

Subtitle.js uses AVA for running tests and nyc for code coverage.

If you want to run these tests, you need to install all devDependencies:

npm install

Now you can run the tests with the following command:

npm test

Code Coverage

You can check the code coverage by running the following command:

npm run coverage

If you want a pretty HTML report, run the following:

npm run report

Your report will be available in the coverage` folder.

License

MIT