/**
 * Base64ArrayBuffer class to encode/decode.
 */
export declare class Base64ArrayBuffer {
    private static chars;
    private static lookupInternal;
    private static scanned;
    private static get lookup();
    /**
     * Encode the array buffer to base64.
     *
     * @param arraybuffer The array buffer.
     * @returns the base64 string.
     */
    static Encode(arraybuffer: ArrayBuffer): string;
    /**
     * Decode the base64 string to array buffer.
     *
     * @param base64 the base64 string.
     * @returns The array buffer.
     */
    static Decode(base64: string): ArrayBuffer;
}