import { NarrationFieldOptions, StripDelimiterPair } from './narration-options';
/** SSML-ish break duration for ElevenLabs (seconds suffix). */
export declare function formatNarrationSourceBreakTime(seconds: number): string;
/** Join narration source excerpts; optional SSML silence between segments. */
export declare function joinNarrationSourcesWithPause(parts: readonly string[], pauseSeconds: number): string;
/**
 * For each pair, repeatedly removes the leftmost region from first `open` through the first
 * `close` after it (inclusive). Pairs run in configured order.
 */
export declare function stripByDelimiterPairs(text: string, pairs: readonly StripDelimiterPair[]): string;
/**
 * Build plain text for TTS from entry data and narration custom-field options.
 * Sources are read in `narrationSources` order (scalar vs blocks per step).
 */
export declare function extractNarrationPlainText(data: Record<string, unknown>, options: NarrationFieldOptions): string;