@holzchopf/flp-file/lib/flp-file.js

Reads and writes FL Studio project and state files.

import { ArrayBufferStream, joinArrayBuffers } from "@holzchopf/array-buffer-stream";
import { FLPDataChunk, FLPHeaderChunk } from "./flp-chunk";
/**
 * Class representing an FL Studio file, which might be a project file (.flp). But other FL Studio files, like state files (.fst) have the same format.
 *
 * Every FLPFile consists of two chunks:
 * - A header chunk, containing file and global project information.
 * - A data chunk, containing event data.
 */
export class FLPFile {
    /**
     * Creates the binary data for this file and returns it.
     */
    getBinary() {
        const buffers = [];
        const write = (chunk) => {
            const type = chunk.type;
            const bytes = chunk.getBinary();
            const stream = new ArrayBufferStream(new ArrayBuffer(4 + 4 + bytes.byteLength));
            stream.writeAsciiString(type);
            stream.writeInt32(bytes.byteLength, true);
            stream.writeBytes(bytes);
            buffers.push(stream.buffer);
        };
        write(this.header);
        write(this.data);
        return joinArrayBuffers(buffers);
    }
    /**
     * Sets this files's values from binary data.
     * @param buffer Binary data.
     */
    setBinary(buffer) {
        const stream = new ArrayBufferStream(buffer);
        while (!stream.eof()) {
            const type = stream.readAsciiString(4);
            const size = stream.readUint32(true);
            const bytes = stream.readBytes(size);
            if (type === 'FLhd') {
                this.header.setBinary(bytes);
            }
            else if (type === 'FLdt') {
                this.data.setBinary(bytes);
            }
        }
    }
    constructor() {
        this.header = new FLPHeaderChunk();
        this.data = new FLPDataChunk();
    }
}