/**
 * QoE (Quality of Experience) accumulator — pure computation layered on the
 * `change()` event stream the player already emits, no new UI
 * (`docs/PLAYER_ROADMAP.md` Phase 3). Every transition it needs is already a
 * `change()` call somewhere else in the player; this module never touches the
 * `<video>` or DOM directly.
 */
export interface PlayerMetrics {
    /** Number of `waiting`→`playing` transitions observed since the last `onLoadStart()`. */
    rebufferCount: number;
    /** Total time (ms) spent between a `waiting` and the `playing` that ended it. */
    rebufferDuration: number;
    /** ms from `onLoadStart()` to the first `canplay`/`playing`, or `null` before either has fired. */
    firstFrameMs: number | null;
    /** Number of user-triggered quality switches (`qualityswitch` change events). */
    qualitySwitchCount: number;
    /** Number of `error`/`sourceerror` change events. */
    errorCount: number;
}
export interface PlayerMetricsController {
    /** Resets all counters and starts the first-frame clock — call at the start of every `updatePlayer()`. */
    onLoadStart: () => void;
    /** Feed every `change(name, value)` call through this — unrecognized names are ignored. */
    record: (name: string, value: unknown) => void;
    getMetrics: () => PlayerMetrics;
}
export declare function createMetricsController(now?: () => number): PlayerMetricsController;