subkit

The subtitles tool kit for converting between SRT, WebVTT, and FCPXML.

Install

npm i subkit

Usage

import fs from "node:fs/promises";
import { dataToVtt, dataToFcpxml, srtToData, srtToFcpxml } from "subkit";

const srt = await fs.readFile("path/to/file.srt", "utf8");

// Convert SRT to data object
const data = srtToData(srt);

// Convert SRT data oject to any format
const vtt = dataToVtt(data);
const fcpxml = dataToFcpxml(data);

// Convert SRT to FCPXML with convertion aliases
const fcpxml_ = srtToFcpxml(srt);
console.log(fcpxml === fcpxml_);
// Output => true

API

SRT

srtToData(text: string): SubSrt

This converts SRT text content to a SubSrt data object.

dataToSrt(data: SubLike, separator?: Separator): string

This accepts a SubLike data as input. The separator is used for timestamp strings and it defaults to ,.

WebVTT

vttToData(text: string): SubVtt

This converts WebVTT text content to a SubVtt data object.

dataToVtt(data: SubLike, separator?: Separator): string;

This accepts a SubLike data as input. The separator is used for timestamp strings and it defaults to ..

FCPXML

fcpxmlToData(text: string): SubFcpxml

This converts FCPXML text context to a SubFcpxml data object.

dataToFcpxml(data: SubLike, fps: number, options?: DataToFcpxmlOptions): string

This accepts a SubLike and fps as input. And some fields can be configured by using DataToFcpxmlOptions.

Convertions

We've defined some convertion aliases for converting between two subs. Available convertion aliases are:

• srtToVtt(text: string, separator?: Separator)
• vttToSrt(text: string, separator?: Separator)
• fcpxmlToSrt(text: string, separator?: Separator)
• fcpxmlToVtt(text: string, separator?: Separator)
• srtToFcpxml(text: string, fps: number, options?: DataToFcpxmlOptions)
• vttToFcpxml(text: string, fps: number, optiosn?: DataToFcpxmlOptions)

Utilities

detectFormat(text: string): 'srt' | 'vtt' | 'fcpxml' | undefined

This can be used to make a quick detection of your subtitles file.

msToTime(ms: string, separator?: Separator): string

This converts the milliseconds to time string for SRT or VTT.

timeToMs(time: string): number

This converts the SRT or VTT time string to milliseconds.

License

MIT