Konoebml

A modern JavaScript implementation of RFC8794 (EBML).

Note

[EBML][EBML] stands for Extensible Binary Meta-Language and is somewhat of a binary version of XML. It's used for container formats like [WebM][webm] or [MKV][mkv].

This package is serving as a fork with extensive rewrites and enhancements to [ebml-web-stream][ebml-web-stream] and [ebml-stream][ebml-stream], providing:

- support new ebml_matroska(v4) while also support legacy version.
- better [unknown size vint][unknown size vint] support
- bigint support for vint, unsigned and signed int data type
- better type system and type hints that depend on it
- better error types

Install

Install via NPM:

``bash
npm install konoebml
`

Usage and Examples

This example reads a media file into memory and decodes it.

`js
import fs from 'node:fs/promises';
import {
ReadableStream,
WritableStream,
type TransformStream,
} from 'node:stream/web';
import { EbmlStreamDecoder } from 'konoebml';

async function main() {
const fileBuffer = await fs.readFile('media/test.webm');
await new ReadableStream({
pull(controller) {
controller.enqueue(fileBuffer);
controller.close();
},
})
.pipeThrough(new EbmlStreamDecoder() as unknown as TransformStream)
.pipeTo(new WritableStream({ write: console.log }));
}

main();
``

Todo: add more docs and tests

State of this project

Parsing and writing should both work. If something is broken, please create [an issue][new-issue].

Any additional feature requests can also be submitted as [an issue][new-issue].

If any well-known tags have special parsing/encoding rules or data structures that aren't implemented, pull requests are welcome!

License

MIT

Other Contributors

(in alphabetical order)

* Austin Blake
* Chris Price
* Davy Van Deursen
* Ed Markowski
* Jonathan Sifuentes
* Liam Dyer
* Manuel Wiedenmann
* Mark Schmale
* Mathias Buus
* Max Ogden
* Oliver Jones
* Oliver Walzer

[EBML]: http://ebml.sourceforge.net/
[mkv]: http://www.matroska.org/technical/specs/index.html
[webm]: https://www.webmproject.org/
[new-issue]: https://github.com/dumtruck/konoebml/issues/new
[unknown size vint]: https://www.rfc-editor.org/rfc/rfc8794.html#name-unknown-data-size
[ebml-web-stream]: https://github.com/Saghen/ebml-web-stream
[ebml-stream]: https://github.com/austinleroy/node-ebml