using System;
using System.Collections.Generic;
using System.Text;
namespace QiHe.CodeLib.Compress.DeflateFormat
{
public static class DeflateCoding
{
/// <summary>
/// Copy lengths for literal codes 257..285
/// </summary>
static int[] CPLENS = {
3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31,
35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258
};
/// <summary>
/// Extra bits for literal codes 257..285
/// </summary>
static int[] CPLEXT = {
0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2,
3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0
};
/// <summary>
/// Copy offsets for distance codes 0..29
/// </summary>
static int[] CPDIST = {
1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193,
257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145,
8193, 12289, 16385, 24577
};
/// <summary>
/// Extra bits for distance codes
/// </summary>
static int[] CPDEXT = {
0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6,
7, 7, 8, 8, 9, 9, 10, 10, 11, 11,
12, 12, 13, 13
};
public const int EndOfBlock = 256;
public static readonly SymbolCoding Length = new SymbolCoding(257, CPLENS, CPLEXT);
public static readonly SymbolCoding Distance = new SymbolCoding(0, CPDIST, CPDEXT);
}
}