/// <reference types="react" />
import * as Tone from 'tone';
import type { SpectrogramDataPoint } from '../main';
export interface UseSpectrogramProps {
    fftSize?: number;
    onReady?: () => void;
    onError?: () => void;
}
/**
 * useSpectrogram is a custom React hook for analyzing and visualizing audio frequencies using Tone.js.
 * It creates an FFT (Fast Fourier Transform) based analyzer to process audio data and provide spectrogram data points.
 *
 * @param {UseSpectrogramProps} props - The configuration properties for the hook.
 * @param {number} props.fftSize - The size of the FFT. Represents the window size in samples that is used when performing a FFT.
 *                                - Default value is 1024.
 *
 * @returns {object} An object containing various properties and methods to interact with the spectrogram:
 * - init: A method to initialize the analyser.
 * - analyser: An instance of Tone.Analyser used for analyzing audio frequencies.
 * - data: An array of spectrogram data points.
 * - getData: A method to fetch the latest spectrogram data from the analyser.
 * - observe: A method to start observing and updating the spectrogram data.
 * - cancelObserve: A method to stop observing the spectrogram data.
 * - error: A boolean indicating whether an error has occurred.
 * - errorMessage: A string containing the error message if an error has occurred.
 */
export declare const useSpectrogram: (props?: UseSpectrogramProps) => {
    analyser: import("react").MutableRefObject<Tone.Analyser | null>;
    data: SpectrogramDataPoint[];
    init: () => void;
    getData: () => void;
    observe: () => void;
    cancelObserve: () => void;
    error: boolean;
    errorMessage: string;
};