export declare class Ddu64 {
    private readonly dduChar;
    private readonly paddingChar;
    private readonly dduCharKr;
    private readonly paddingCharKr;
    private readonly defaultEncoding;
    private readonly bitLengthMap;
    private readonly binaryLookup;
    private readonly dduBinaryLookup;
    private readonly dduBinaryLookupKr;
    private readonly paddingRegex;
    constructor(dduChar?: string[] | string, paddingChar?: string);
    private getBitLength;
    private getLargestPowerOfTwo;
    private splitString;
    private getSelectedSets;
    private bufferToDduBinary;
    private dduBinaryToBuffer;
    encode(input: Buffer | string, options?: {
        dduSetSymbol?: string;
        encoding?: BufferEncoding;
        usePowerOfTwo?: boolean;
    }): string;
    decode(input: string, options?: {
        dduSetSymbol?: string;
        encoding?: BufferEncoding;
        usePowerOfTwo?: boolean;
    }): string;
}
export declare class Custom64 {
    private readonly dduChar;
    private readonly paddingChar;
    private readonly dduCharKr;
    private readonly paddingCharKr;
    private readonly defaultEncoding;
    private readonly bitLengthMap;
    private readonly binaryLookup;
    private readonly dduBinaryLookup;
    private readonly dduBinaryLookupKr;
    private readonly paddingRegex;
    constructor(dduChar?: string[] | string, paddingChar?: string);
    private getBitLength;
    private getLargestPowerOfTwo;
    private splitString;
    private getSelectedSets;
    private bufferToDduBinary;
    private dduBinaryToBuffer;
    encode(input: Buffer | string, options?: {
        dduSetSymbol?: string;
        encoding?: BufferEncoding;
        usePowerOfTwo?: boolean;
    }): string;
    decode(input: string, options?: {
        dduSetSymbol?: string;
        encoding?: BufferEncoding;
        usePowerOfTwo?: boolean;
    }): string;
}