@nomercy-entertainment/nomercy-subtitle-octopus

NoMercy-owned TypeScript wrapper around the libass-wasm (SubtitleOctopus) WASM renderer.

This package is not a fork of upstream — it's a thin consumer-side wrapper that adds the patches NoMercy needs without modifying the WASM worker. The actual fork of libass/JavascriptSubtitlesOctopus lives at @nomercy-entertainment/libass-wasm — that package owns the C++ source, Emscripten build pipeline, and the binaries.

Patches owned here (main-thread, TypeScript)

• Bearer token auth — pre-fetch subtitle + font files on the main thread with Authorization: Bearer <token>, hand the worker blob URLs. Worker stays unmodified, never makes auth-required calls. Custom request schemes (nmsync:, cast:, data:, blob:, file:, etc.) bypass the same-origin guard so the token never leaks onto requests that can't carry it.
• Cross-origin worker instantiation — Blob URL + importScripts() shim so workers load from a different origin (CDN deployments).
• Canvas geometry sync — ResizeObserver against a configurable geometrySource element; copies six CSS properties to canvasParent so the libass canvas tracks the player's overlay through fullscreen / theater / float transitions.
• Lifecycle race guards — currentLoadedUrl + race-token pattern, orphan canvas sweep, idempotent dispose.
• URL resolution — basePath prepend with proper RFC-3986 absolute-URL detection (any scheme, plus protocol-relative //host/path).

Binaries

public/subtitles-octopus-worker.{js,wasm} and public/default.ttf are vendored from upstream libass-wasm@4.1.0 pending a first NoMercy build out of the sister fork (@nomercy-entertainment/libass-wasm). License chain reproduced in COPYRIGHT.

Worker files — copy to public

The libass WASM worker files ship inside this package's dist/ directory. Your build tool must copy them into the public/static directory so the browser can load them:

// vite.config.ts
import { viteStaticCopy } from 'vite-plugin-static-copy';

export default {
	plugins: [
		viteStaticCopy({
			targets: [
				{
					src: 'node_modules/@nomercy-entertainment/nomercy-subtitle-octopus/dist/subtitles-octopus-worker*.{js,wasm,data}',
					dest: 'static',
				},
			],
		}),
	],
};

Then pass the copied paths when registering the plugin:

player.addPlugin(OctopusPlugin, {
	workerUrl: '/static/subtitles-octopus-worker.js',
	legacyWorkerUrl: '/static/subtitles-octopus-worker-legacy.js',
});

Usage

import { NMSubtitleOctopus } from '@nomercy-entertainment/nomercy-subtitle-octopus';

// Pre-fetch subtitle bytes and font binaries with whatever auth pipeline you use.
const trackContent = await fetchAuthedText('/episode-1.ass');
const availableFonts = await fetchAuthedFonts('/fonts/');

const octopus = new NMSubtitleOctopus({
	video: videoElement,
	trackContent,
	availableFonts,
	geometrySource: playerContainer,
});

octopus.on('rendererReady', ({ url }) => console.log('renderer ready', url));

The renderer never performs authenticated network I/O — your consumer (or the NoMercy player kit) pre-fetches every byte the worker needs and passes it as trackContent plus a name → blob:URL font map.

License

MIT — TypeScript wrapper code. The vendored WASM artefact carries the upstream license chain (LGPL-2.1 / FTL / GPL-2.0 / MIT / ISC / NTP / Zlib / BSL-1.0) reproduced in COPYRIGHT.