Parses various subtitle formats (VTT/TTML/TTAF) into a type called SubtitleData.
There are various generators that take SubtitleData and emit text (SRT/ASS).
npm i -g subtitle-transform
With a file:
subtitle-transform --input=ep1.vtt --inputFormat=vtt --outputFormat=ass
or pipe:
cat ep1.vtt | subtitle-transform --inputFormat=vtt --outputFormat=ass
You can also pass --timestampSkew=-2.1 to adjust timestamps.
npm i -S subtitle-transform
import { parseTT, generateASS } from 'subtitle-transform';
const inputContents = `<?xml version="1.0" encoding="utf-8"?>
<tt xmlns="http://www.w3.org/2006/10/ttaf1" xml:lang="en" xmlns:ttm="http://www.w3.org/2006/10/ttaf1#metadata">
<head>
<!--Created on 1/11/2011 at 00:30:00-->
<metadata>
<ttm:title>
Yellow eggs and potatoes
</ttm:title>
<ttm:copyright>
Paul
</ttm:copyright>
</metadata>
<styling>
<style id="s0" tts:backgroundColor="black" tts:fontStyle="normal" tts:fontSize="16" tts:fontFamily="sansSerif" tts:color="white" />
<style id="s1" style="s0" tts:color="yellow" />
</styling>
</head>
<body tts:textAlign="center" style="s0">
<div>
<p begin="00:01:57.32" id="p0" end="00:01:58.36">First caption!</p>
<p begin="00:02:11.44" id="p3" end="00:02:16.44">A what<br />oh</p>
<p style="s1" begin="00:03:01.88" id="p14" end="00:03:04.64"><span tts:color="white">This line is white<br /></span>This line is something else</p>
</div>
</body>
</tt>`;
const subtitleData = parseTT(inputContents, {});
const output = generateASS(subtitleData, { enableStyles: true });
console.log(output);- VTT parsing
- Style support
- TT parsing
- Style support
- ASS parsing
- Style support
- SRT output
- Style support
- ASS output
- Style support
- Region support
- VTT output
- Style support
- Region support
Resources used:
- https://www.w3.org/TR/webvtt1/#file-parsing
- https://developer.mozilla.org/en-US/docs/Web/API/WebVTT_API
- https://github.com/mozilla/vtt.js
- https://chromium.googlesource.com/chromium/blink/+/e79071b4c4e899957766312459dd4a5199bf266d/Source/core/html/track/vtt/
- https://github.com/libass/libass/blob/master/libass/ass_parse.c
- https://matroska.org/technical/specs/subtitles/ssa.html
- http://ale5000.altervista.org/subtitles.htm
- http://docs.aegisub.org/3.2/ASS_Tags/