/**
 * Huffman decode: build decode table from weights, decode symbols.
 * Zstd Huffman streams are read backward.
 */
import type { BitReaderReverse } from '../bitstream/bitReaderReverse.js';
export interface HuffmanDecodeTable {
    symbol: Uint8Array;
    numBits: Uint8Array;
    maxNumBits: number;
    length: number;
}
/**
 * Convert weights to number of bits per symbol.
 * Weight = 0 means symbol not present. Weight 1 = least frequent, max weight = most frequent.
 * Number_of_Bits = Weight ? (Max_Number_of_Bits + 1 - Weight) : 0
 */
export declare function weightsToNumBits(weights: readonly number[], maxNumBits: number): number[];
/**
 * Build Huffman decode table from symbol bit lengths.
 * Returns table indexed by prefix code (first maxNumBits bits).
 */
export declare function buildHuffmanDecodeTable(numBits: readonly number[], maxNumBits: number): HuffmanDecodeTable;
/**
 * Decode one Huffman symbol. Reader must be positioned at start of code.
 */
export declare function decodeHuffmanSymbol(table: HuffmanDecodeTable, reader: BitReaderReverse): number;