/// <reference types="node" />
import { Transform, TransformCallback } from "stream";
import { SpectralBuffer } from "../SpectralBuffer";
import { Smp, Hz } from "../global";
interface SpectralMagnitudesChunk {
    magnitudes: number[];
    magnitudesByChannel?: number[][];
    time: Smp;
    sampleRate: Hz;
}
declare class SpectralMagnitudes extends Transform {
    constructor();
    _transform(chunk: SpectralBuffer, encoding: string, callback: TransformCallback): void;
}
declare class MonoSpectralMagnitudes extends Transform {
    constructor();
    _transform(chunk: SpectralBuffer, encoding: string, callback: TransformCallback): void;
}
export { SpectralMagnitudes, MonoSpectralMagnitudes, SpectralMagnitudesChunk };