@blamnetwork/blf

Install & quick start ​

Install ​

bash
npm install @blamnetwork/blf

@craftycodie/cstruct is installed automatically as a dependency — you do not need to add it unless you are developing chunk layouts in this repository.

Use TypeScript 5.x. Consumers only need the published types under dist/; no decorator configuration is required for normal use.

Read a BLF ​

Read a Halo Reach TU1 BLF and decode its content header and game variant (mpvr) chunks:

ts
import { readFileSync } from "node:fs";
import { find_chunk } from "@blamnetwork/blf";
import {
  s_blf_chunk_content_header,
  s_blf_chunk_game_variant,
} from "@blamnetwork/blf/haloreach/v12065_11_08_24_1738_tu1actual";

const file = new Uint8Array(readFileSync("variant.blf"));

const chdr = new s_blf_chunk_content_header();
find_chunk(file, chdr, "big");

const mpvr = new s_blf_chunk_game_variant();
find_chunk(file, mpvr, "big");

Pass "big" or "little" for chunk payload endianness (BLF headers are always big-endian). Reach mpvr gametypes use big-endian bitstreams internally. Instantiate the chunk class, then call find_chunk — fields are filled in place.

Next: Reading chunks and Writing chunks, or Version bundles to pick the right import path.