import { VADAdapter, VADConfig, VADState, VADFactory, VADMetadata, VADEventEmitter } from '../';
/**
 * Simple VAD Adapter Configuration
 */
export interface SimpleVADConfig extends VADConfig {
    /** Energy threshold for speech detection (0-1, default: 0.15) */
    energyThreshold?: number;
    /** Minimum duration of silence (in frames) before speech is considered ended (default: 8) */
    redemptionFrames?: number;
}
/**
 * Simple VAD Adapter
 *
 * Energy-based voice activity detection using RMS analysis.
 * Fast, lightweight, requires no model downloads, but less accurate than ML-based VADs.
 *
 * This adapter is designed to run alongside Silero VAD as a redundant check.
 * If Simple VAD doesn't detect speech for an extended period while Silero VAD
 * is still detecting speech, it can signal that Silero VAD should be paused/cancelled.
 */
export declare class SimpleVADAdapter extends VADEventEmitter implements VADAdapter {
    readonly id = "simple-vad";
    readonly name = "Simple VAD (Energy-based)";
    readonly version = "1.0.0";
    private config;
    private state;
    private initialized;
    private isSpeakingFlag;
    private silenceFrames;
    private lastSpeechFrameTime;
    constructor(config?: Partial<SimpleVADConfig>);
    /**
     * Initialize the Simple VAD adapter
     *
     * Note: Simple VAD requires no initialization - it's ready immediately
     */
    initialize(): Promise<void>;
    /**
     * Process audio frame using energy-based detection
     *
     * @param frame - Audio frame as Float32Array (typically 16kHz mono)
     * @param timestamp - Frame timestamp in milliseconds
     * @returns Speech probability (0.0 to 1.0) or null if not ready
     */
    processFrame(frame: Float32Array, timestamp: number): number | null;
    /**
     * Calculate RMS (Root Mean Square) energy from audio samples
     *
     * @param samples - Audio samples as Float32Array
     * @returns RMS energy value
     */
    private calculateRMS;
    configure(config: VADConfig): void;
    reset(): void;
    dispose(): void;
    isReady(): boolean;
    getState(): VADState;
    /**
     * Check if currently detecting speech
     */
    isSpeaking(): boolean;
    /**
     * Get time since last speech detection (in milliseconds)
     * Returns 0 if currently speaking
     */
    getTimeSinceLastSpeech(currentTimestamp: number): number;
}
/**
 * Simple VAD Factory
 */
export declare class SimpleVADFactory implements VADFactory {
    create(config?: Partial<SimpleVADConfig>): SimpleVADAdapter;
    getMetadata(): VADMetadata;
}
/**
 * Register Simple VAD adapter with VAD Registry
 *
 * This function ensures the SimpleVADAdapter is registered.
 * The adapter auto-registers when the module is imported, but this function
 * can be called explicitly to ensure registration.
 *
 * @returns void
 */
export declare function registerSimpleVADAdapter(): void;
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