mediabunny/src/wave/riff-reader.ts

import { Reader } from '../reader';

export class RiffReader {
	pos = 0;
	littleEndian = true;

	constructor(public reader: Reader) {}

	readBytes(length: number) {
		const { view, offset } = this.reader.getViewAndOffset(this.pos, this.pos + length);
		this.pos += length;

		return new Uint8Array(view.buffer, offset, length);
	}

	readU16() {
		const { view, offset } = this.reader.getViewAndOffset(this.pos, this.pos + 2);
		this.pos += 2;

		return view.getUint16(offset, this.littleEndian);
	}

	readU32() {
		const { view, offset } = this.reader.getViewAndOffset(this.pos, this.pos + 4);
		this.pos += 4;

		return view.getUint32(offset, this.littleEndian);
	}

	readAscii(length: number) {
		const { view, offset } = this.reader.getViewAndOffset(this.pos, this.pos + length);
		this.pos += length;

		let str = '';
		for (let i = 0; i < length; i++) {
			str += String.fromCharCode(view.getUint8(offset + i));
		}
		return str;
	}
}