import EncodedTransform from './EncodedTransform';
/**
 * Message types specific to MediaMetrics transforms.
 */
export declare const MEDIA_METRICS_MESSAGE_TYPES: {
    readonly NEW_SSRC: "NewSSRC";
};
/**
 * Metrics for a single media stream identified by SSRC.
 * Collected from encoded transform workers processing RTP packets.
 */
export interface EncodedTransformMediaStreamMetrics {
    /**
     * Synchronization source identifier for the stream.
     */
    ssrc: number;
    /**
     * Number of packets processed in the reporting interval.
     */
    packetCount: number;
    /**
     * Unix timestamp when metrics were collected.
     */
    timestamp: number;
}
/**
 * Abstract base class for packet-level metrics collection per SSRC.
 * Tracks packet counts and timestamps, periodically reporting to the main thread.
 */
declare abstract class BaseMetricsTransform extends EncodedTransform {
    protected metricsMap: Map<number, {
        packetCount: number;
        timestamp: number;
    }>;
    protected readonly reportIntervalMs: number;
    protected lastReportTime: number;
    /** Returns the transform name for metrics identification. */
    protected abstract transformName(): string;
    /** Processes frames, collects per-SSRC metrics, and forwards unchanged. */
    transform(frame: RTCEncodedAudioFrame | RTCEncodedVideoFrame, controller: TransformStreamDefaultController<RTCEncodedAudioFrame | RTCEncodedVideoFrame>): void;
    /** Posts aggregated metrics to the main thread via postMessage. */
    protected reportMetrics(): void;
}
/** Collects packet-level metrics for outbound audio streams. */
export declare class AudioSenderMetricsTransform extends BaseMetricsTransform {
    protected transformName(): string;
}
/** Collects packet-level metrics for inbound audio streams. */
export declare class AudioReceiverMetricsTransform extends BaseMetricsTransform {
    protected transformName(): string;
}
/** Collects packet-level metrics for outbound video streams. */
export declare class VideoSenderMetricsTransform extends BaseMetricsTransform {
    protected transformName(): string;
}
/** Collects packet-level metrics for inbound video streams. */
export declare class VideoReceiverMetricsTransform extends BaseMetricsTransform {
    protected transformName(): string;
}
export {};