/**
 * Performance monitoring and metrics collection for audio streams.
 * Tracks buffer health, processing times, and diagnostic events.
 */
/**
 * Performance metrics collected over time.
 */
export interface StreamMetrics {
    /** Total number of write operations */
    writeCount: number;
    /** Total frames processed */
    framesProcessed: number;
    /** Buffer underrun count */
    underrunCount: number;
    /** Buffer overrun count */
    overrunCount: number;
    /** Processing time statistics (milliseconds) */
    processingTime: {
        min: number;
        max: number;
        average: number;
        recent: number;
    };
    /** Buffer fill statistics (0.0-1.0) */
    bufferFill: {
        min: number;
        max: number;
        average: number;
        current: number;
    };
    /** Latency measurements (milliseconds) */
    latency: {
        min: number;
        max: number;
        average: number;
        current: number;
    };
    /** Real-time performance ratio (1.0 = perfect real-time) */
    realTimeRatio: number;
    /** Timestamp of last update */
    lastUpdate: number;
}
/**
 * Diagnostic event types for stream health monitoring.
 */
export declare enum DiagnosticEvent {
    /** Buffer underrun detected - increase buffer size */
    BufferUnderrun = "buffer-underrun",
    /** Buffer overrun detected - reduce input rate */
    BufferOverrun = "buffer-overrun",
    /** Processing taking too long - optimize or increase buffer */
    ProcessingDelay = "processing-delay",
    /** Format negotiation failed */
    FormatMismatch = "format-mismatch",
    /** Latency spike detected */
    LatencySpike = "latency-spike",
    /** Buffer size adjusted automatically */
    BufferAdjusted = "buffer-adjusted",
    /** Performance degradation detected */
    PerformanceDrop = "performance-drop"
}
/**
 * Diagnostic event with context information.
 */
export interface DiagnosticEventInfo {
    event: DiagnosticEvent;
    timestamp: number;
    severity: "info" | "warning" | "error";
    message: string;
    data?: Record<string, unknown>;
    suggestion?: string;
}
/**
 * Performance monitor for audio streams.
 * Collects metrics and emits diagnostic events.
 */
export declare class StreamPerformanceMonitor {
    private readonly rate;
    private readonly channels;
    private readonly bufferSize;
    private readonly metrics;
    private readonly maxSamples;
    private readonly processingTimes;
    private readonly bufferFills;
    private readonly latencies;
    private lastProcessingTime;
    private readonly eventCallbacks;
    constructor(rate: number, channels: number, bufferSize: number);
    /**
     * Record a write operation with performance data.
     */
    recordWrite(frameCount: number, processingTimeMs: number, bufferFillRatio: number): void;
    /**
     * Record a buffer underrun event.
     */
    recordUnderrun(): void;
    /**
     * Record a buffer overrun event.
     */
    recordOverrun(): void;
    /**
     * Update latency measurement.
     */
    recordLatency(latencyMs: number): void;
    /**
     * Get current performance metrics.
     */
    getMetrics(): StreamMetrics;
    /**
     * Subscribe to diagnostic events.
     */
    onDiagnostic(event: DiagnosticEvent, callback: (info: DiagnosticEventInfo) => void): void;
    /**
     * Unsubscribe from diagnostic events.
     */
    offDiagnostic(event: DiagnosticEvent, callback: (info: DiagnosticEventInfo) => void): void;
    /**
     * Get health assessment of the stream.
     */
    getHealthAssessment(): {
        overall: "good" | "warning" | "critical";
        issues: Array<string>;
        suggestions: Array<string>;
    };
    private checkDiagnostics;
    private emitDiagnostic;
}