/**
 * FSE (Finite State Entropy) decode: table build and symbol decode.
 * Zstd FSE streams are read backward.
 */
import type { BitReaderReverse } from '../bitstream/bitReaderReverse.js';
export interface FSEDecodeTable {
    symbol: Uint16Array;
    numBits: Uint8Array;
    baseline: Int32Array;
    tableLog: number;
    length: number;
}
/**
 * Build FSE decode table from normalized counts.
 * Counts are -1 for "less than 1" (full state reset) symbols.
 * Based on zstd FSE_buildDTable logic.
 */
export declare function buildFSEDecodeTable(normalizedCounter: readonly number[], tableLog: number): FSEDecodeTable;
/**
 * Decode one FSE symbol. Updates state in place.
 */
export declare function decodeFSESymbol(table: FSEDecodeTable, reader: BitReaderReverse, state: {
    value: number;
}): number;
/**
 * Read FSE normalized counts from compressed header (readNCount).
 * Used when symbol type uses RLE or Compressed mode (not Predefined).
 * Bitstream is read forward, little-endian.
 */
export declare function readNCount(data: Uint8Array, offset: number, maxSymbolValue: number, maxTableLog: number): {
    normalizedCounter: number[];
    tableLog: number;
    maxSymbolValue: number;
    bytesRead: number;
};
export declare function normalizeCountsForTable(counts: readonly number[], tableLog: number): {
    normalizedCounter: number[];
    maxSymbolValue: number;
};
export declare function writeNCount(normalizedCounter: readonly number[], maxSymbolValue: number, tableLog: number): Uint8Array;