/** Derived locations use UTF-16 string offsets; they are never persisted separately. */
export interface ManuscriptKeyframeAnchor {
    id: string;
    offsetSeconds: number;
    startOffset: number;
    endOffset: number;
    contentStartOffset: number;
    contentEndOffset: number;
    text: string;
}
/** Detect the reserved prefix, including malformed markers that require an error. */
export declare function hasManuscriptKeyframes(manuscript: string): boolean;
/**
 * Parse authored locations without changing prose or repairing invalid positions.
 * @param unitId Owner of the inline keyframe IDs.
 * @param durationSeconds Unit-local duration, excluding the final endpoint.
 * @param manuscript Formal prose, or a legacy unmarked manuscript.
 * @param inheritedOpening Whether time zero comes from the preceding video.
 * @param allowMissingOpening Whether unlinking left an opening awaiting authoring.
 * @returns Ordered locations and explicit authoring errors; legacy prose has no locations.
 */
export declare function parseVideoUnitManuscript(unitId: string, durationSeconds: number, manuscript: string, inheritedOpening?: boolean, allowMissingOpening?: boolean): {
    anchors: ManuscriptKeyframeAnchor[];
    issues: string[];
};
/** Remove complete marker lines for density estimates without changing manual Full Prompts. */
export declare function stripManuscriptKeyframeMarkers(manuscript: string): string;
/**
 * Scale inline times at millisecond precision, preserving every non-marker byte.
 * @param unitId Owner of the manuscript.
 * @param manuscript Current text, including anchors without generated products.
 * @param oldDuration Original Unit duration.
 * @param newDuration Requested Unit duration.
 * @param inheritedOpening Whether the opening is inherited from the preceding video.
 * @param allowMissingOpening Whether unlinking left an opening awaiting authoring.
 * @returns Text with normalized marker times; throws before returning invalid timing.
 */
export declare function scaleVideoUnitManuscript(unitId: string, manuscript: string, oldDuration: number, newDuration: number, inheritedOpening?: boolean, allowMissingOpening?: boolean): string;
/**
 * Project a duration-only change through both prose and existing keyframe records.
 * @param unit Saved Unit timing and products.
 * @param durationSeconds New duration.
 * @returns Synchronized manuscript and keyframes, retaining unrelated product fields.
 */
export declare function resizeVideoUnitTiming<T extends {
    id: string;
    offsetSeconds: number;
}>(unit: {
    id: string;
    manuscript: string;
    durationSeconds: number;
    keyframes: readonly T[];
    dependency?: {
        unitId: string;
    };
    openingRequired?: boolean;
}, durationSeconds: number): {
    manuscript: string;
    keyframes: T[];
};