/**
 * Voice Recorder Utility
 * Provides audio recording functionality with waveform visualization support.
 */
export interface VoiceRecorderOptions {
    /** Maximum recording duration in milliseconds (default: 300000 = 5 minutes) */
    maxDuration?: number;
    /** Audio bits per second (default: 128000) */
    audioBitsPerSecond?: number;
}
export interface VoiceRecordingResult {
    /** The recorded audio blob */
    audioBlob: Blob;
    /** Recording duration in milliseconds */
    duration: number;
    /** MIME type of the audio */
    mimeType: string;
}
export type VoiceRecorderEventCallback<T = void> = (data: T) => void;
/**
 * VoiceRecorder class for handling audio recording with visualization support.
 */
export declare class VoiceRecorder {
    private mediaRecorder;
    private audioChunks;
    private isRecording;
    private stream;
    private recordingStartTime;
    private maxDuration;
    private audioBitsPerSecond;
    private mimeType;
    private audioContext;
    private analyser;
    private animationFrame;
    private onStartCallback?;
    private onStopCallback?;
    private onErrorCallback?;
    private onAudioLevelCallback?;
    private onDurationUpdateCallback?;
    private durationInterval;
    constructor(options?: VoiceRecorderOptions);
    /**
     * Check if the browser supports audio recording.
     */
    static isSupported(): boolean;
    /**
     * Get the best supported MIME type for recording.
     */
    private getSupportedMimeType;
    /**
     * Start audio recording.
     * @returns Promise that resolves to true if recording started successfully.
     */
    startRecording(): Promise<boolean>;
    /**
     * Stop audio recording.
     */
    stopRecording(): void;
    /**
     * Cancel audio recording without emitting the result.
     */
    cancelRecording(): void;
    /**
     * Check if currently recording.
     */
    isCurrentlyRecording(): boolean;
    /**
     * Get recording duration in milliseconds.
     */
    getRecordingDuration(): number;
    /**
     * Set up audio analysis for waveform visualization.
     */
    private setupAudioAnalysis;
    /**
     * Start monitoring audio levels for visualization.
     */
    private startAudioLevelMonitoring;
    /**
     * Start duration update interval.
     */
    private startDurationUpdates;
    /**
     * Stop duration update interval.
     */
    private stopDurationUpdates;
    /**
     * Clean up resources.
     */
    private cleanup;
    /**
     * Destroy the recorder and clean up all resources.
     */
    destroy(): void;
    /**
     * Set callback for when recording starts.
     */
    onStart(callback: VoiceRecorderEventCallback): this;
    /**
     * Set callback for when recording stops with the result.
     */
    onStop(callback: VoiceRecorderEventCallback<VoiceRecordingResult>): this;
    /**
     * Set callback for recording errors.
     */
    onError(callback: VoiceRecorderEventCallback<string>): this;
    /**
     * Set callback for audio level updates (for waveform visualization).
     * Level is normalized between 0 and 1.
     */
    onAudioLevel(callback: VoiceRecorderEventCallback<number>): this;
    /**
     * Set callback for duration updates (in milliseconds).
     */
    onDurationUpdate(callback: VoiceRecorderEventCallback<number>): this;
    /**
     * Format duration in milliseconds to MM:SS format.
     */
    static formatDuration(ms: number): string;
}
export default VoiceRecorder;