/// <reference types="node" />
import { DeferredPromise, OpusInfo } from './types';
import * as Api from './api';
import { Logger } from 'pino';
import { Duplex, DuplexOptions, Transform, TransformCallback, TransformOptions } from 'stream';
export declare function encodeCodecHeader(opusInfo: OpusInfo): string;
export declare function decodeCodecHeader(codecHeader: string): OpusInfo;
export declare function packPacket(packet: Api.Packet): Buffer;
export declare function unpackPacket(data?: Buffer): Api.Packet | undefined;
export declare function getTime(): bigint;
export declare function isEnvVar(envVar: any): boolean;
export declare type StabilizeStreamOptions = DuplexOptions & {
    bufferSize: number;
    logger: Logger;
};
export declare class StabilizeStream extends Duplex {
    queue: Buffer[];
    logger: Logger;
    queueSize: number;
    requestedSize: number;
    queueMaxSize: number;
    waiting: boolean;
    deferredWritePromise?: DeferredPromise<number>;
    constructor(opts: StabilizeStreamOptions);
    /**
     * Read data from the internal queue and send it further
     */
    realRead(): void;
    _write(chunk: any, encoding: BufferEncoding, callback: (error?: Error | null) => void): Promise<void>;
    _read(size: number): void;
    _final(callback: (error?: Error | null) => void): void;
}
export declare type DataWaitPassThroughStreamOptions = TransformOptions;
export declare class DataWaitPassThroughStream extends Transform {
    dataIsReady: boolean;
    constructor(opts?: DataWaitPassThroughStreamOptions);
    _transform(chunk: any, encoding: BufferEncoding, callback: TransformCallback): void;
}