import { ByteArray } from '../types.js';
import { PdfArray } from '../core/objects/pdf-array.js';
/**
 * Builds a character encoding map from a PDF Encoding Differences array.
 * The Differences array format is: [code name1 name2 ... code name1 name2 ...]
 * where code is a number and names are glyph names.
 *
 * @param differences - PdfArray containing the Differences array
 * @returns Map from byte code to Unicode character
 */
export declare function buildEncodingMap(differences: PdfArray): Map<number, string> | null;
/**
 * Decodes a byte array using a custom font encoding map.
 * Falls back to PDFDocEncoding for unmapped bytes.
 *
 * @param bytes - The byte array to decode
 * @param encodingMap - Map from byte code to Unicode character
 * @returns The decoded string
 */
export declare function decodeWithFontEncoding(bytes: ByteArray, encodingMap: Map<number, string> | null): string;