?? lzhuf.cpp
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// Created:09-24-98
// By Jeff Connelly
// LZHUF (LZSS combined with Huffman) compression
// Original authors Haruyasu Yoshizaki, Haruhiko Okumura, and Kenji Rikitake
// only allow it to be used for non-commercial purposes.
// Based on ORIGSRC\LZHUF.C
#include "stdafx.h"
#define EXPORTING
#include "comprlib.h"
#include "lzhuf.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
static unsigned long textsize = 0, codesize = 0;
// **************** LZSS compression ***********
#define N 4096 // buffer size
#define F 60 // lookahead buffer size
#define THRESHOLD 2
#define NIL N // leaf of tree
static unsigned char text_buf[N + F - 1];
static int match_position, match_length, lson[N + 1], rson[N + 257];
static int dad[N + 1];
// Initalize trees
static void InitTree ()
{
int i;
for (i = N + 1; i <= N + 256; i++)
rson[i] = NIL; // root
for (i = 0; i < N; i++)
dad[i] = NIL; // node
}
// Insert to tree
static void InsertNode(int r)
{
int i, p, cmp;
unsigned char* key;
unsigned c;
cmp = 1;
key = &text_buf[r];
p = N + 1 + key[0];
rson[r] = lson[r] = NIL;
match_length = 0;
while (true)
{
if (cmp >= 0)
{
if (rson[p] != NIL)
p = rson[p];
else
{
rson[p] = r;
dad[r] = p;
return;
}
} else {
if (lson[p] != NIL)
p = lson[p];
else
{
lson[p] = r;
dad[r] = p;
return;
}
}
for (i = 1; i < F; i++)
if ((cmp = key[i] - text_buf[p + i]) != 0)
break;
if (i > THRESHOLD)
{
if (i > match_length)
{
match_position = ((r - p) & (N - 1)) - 1;
if ((match_length = i) >= F)
break;
}
if (i == match_length)
{
if ((c = ((r - p) & (N - 1)) - 1) < (unsigned)match_position)
match_position = c;
}
}
}
dad[r] = dad[p];
lson[r] = lson[p];
rson[r] = rson[p];
dad[lson[p]] = r;
dad[rson[p]] = r;
if (rson[dad[p]] == p)
rson[dad[p]] = r;
else
lson[dad[p]] = r;
dad[p] = NIL; // remove 'p'
}
// remove node from tree
static void DeleteNode (int p)
{
int q;
if (dad[p] == NIL)
return; // not in tree
if (rson[p] == NIL)
q = lson[p];
else
if (lson[p] == NIL)
q = rson[p];
else
{
q = lson[p];
if (rson[q] != NIL)
{
do
{
q = rson[q];
} while (rson[q] != NIL);
rson[dad[q]] = lson[q];
dad[lson[q]] = dad[q];
lson[q] = lson[p];
dad[lson[p]] = q;
}
rson[q] = rson[p];
dad[rson[p]] = q;
}
dad[q] = dad[p];
if (rson[dad[p]] == p)
rson[dad[p]] = q;
else
lson[dad[p]] = q;
dad[p] = NIL;
}
// ********** Huffman coding *******
#define N_CHAR (256 - THRESHOLD + F) // Kinds of characters
#define T (N_CHAR * 2 - 1) // size of table
#define R (T - 1) // position of root
// update tree when the root frequency comes to this value.
#define MAX_FREQ 0x8000
typedef unsigned char uchar;
// Table for encoding and decoding the upper 6 bits of position
// For encoding
static uchar p_len[64] =
{
0x03, 0x04, 0x04, 0x04, 0x05, 0x05, 0x05, 0x05,
0x05, 0x05, 0x05, 0x05, 0x06, 0x06, 0x06, 0x06,
0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06,
0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07,
0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07,
0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07,
0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08,
0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08
};
static uchar p_code[64] =
{
0x00, 0x20, 0x30, 0x40, 0x50, 0x58, 0x60, 0x68,
0x70, 0x78, 0x80, 0x88, 0x90, 0x94, 0x98, 0x9C,
0xA0, 0xA4, 0xA8, 0xAC, 0xB0, 0xB4, 0xB8, 0xBC,
0xC0, 0xC2, 0xC4, 0xC6, 0xC8, 0xCA, 0xCC, 0xCE,
0xD0, 0xD2, 0xD4, 0xD6, 0xD8, 0xDA, 0xDC, 0xDE,
0xE0, 0xE2, 0xE4, 0xE6, 0xE8, 0xEA, 0xEC, 0xEE,
0xF0, 0xF1, 0xF2, 0xF3, 0xF4, 0xF5, 0xF6, 0xF7,
0xF8, 0xF9, 0xFA, 0xFB, 0xFC, 0xFD, 0xFE, 0xFF
};
// for decoding
static uchar d_code[256] =
{
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01,
0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01,
0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02,
0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02,
0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03,
0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03,
0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04,
0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05,
0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06,
0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07,
0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08,
0x09, 0x09, 0x09, 0x09, 0x09, 0x09, 0x09, 0x09,
0x0A, 0x0A, 0x0A, 0x0A, 0x0A, 0x0A, 0x0A, 0x0A,
0x0B, 0x0B, 0x0B, 0x0B, 0x0B, 0x0B, 0x0B, 0x0B,
0x0C, 0x0C, 0x0C, 0x0C, 0x0D, 0x0D, 0x0D, 0x0D,
0x0E, 0x0E, 0x0E, 0x0E, 0x0F, 0x0F, 0x0F, 0x0F,
0x10, 0x10, 0x10, 0x10, 0x11, 0x11, 0x11, 0x11,
0x12, 0x12, 0x12, 0x12, 0x13, 0x13, 0x13, 0x13,
0x14, 0x14, 0x14, 0x14, 0x15, 0x15, 0x15, 0x15,
0x16, 0x16, 0x16, 0x16, 0x17, 0x17, 0x17, 0x17,
0x18, 0x18, 0x19, 0x19, 0x1A, 0x1A, 0x1B, 0x1B,
0x1C, 0x1C, 0x1D, 0x1D, 0x1E, 0x1E, 0x1F, 0x1F,
0x20, 0x20, 0x21, 0x21, 0x22, 0x22, 0x23, 0x23,
0x24, 0x24, 0x25, 0x25, 0x26, 0x26, 0x27, 0x27,
0x28, 0x28, 0x29, 0x29, 0x2A, 0x2A, 0x2B, 0x2B,
0x2C, 0x2C, 0x2D, 0x2D, 0x2E, 0x2E, 0x2F, 0x2F,
0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37,
0x38, 0x39, 0x3A, 0x3B, 0x3C, 0x3D, 0x3E, 0x3F,
};
static uchar d_len[256] =
{
0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03,
0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03,
0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03,
0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03,
0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04,
0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04,
0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04,
0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04,
0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04,
0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04,
0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05,
0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05,
0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05,
0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05,
0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05,
0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05,
0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05,
0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05,
0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06,
0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06,
0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06,
0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06,
0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06,
0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06,
0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07,
0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07,
0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07,
0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07,
0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07,
0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07,
0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08,
0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08,
};
static unsigned freq[T + 1]; // frequency table
// Pointers to parent nodes, except for the elements [T..T + N_CHAR -1]
// which are used to get the positions of leaves corresponding to the codes.
static int prnt[T + N_CHAR];
static int son[T]; // pointers to child nodes (son[], son[] + 1)
static unsigned getbuf = 0;
static uchar getlen = 0;
// Read one bit
static int GetBit ()
{
int i;
while (getlen <= 8)
{
if ((i = read_byte()) < 0)
i = 0;
getbuf |= i << (8 - getlen);
getlen += 8;
}
i = getbuf;
getbuf <<= 1;
--getlen;
return (i < 0);
}
// Read one byte
static int GetByte()
{
unsigned i;
while (getlen <= 8)
{
if ((i = read_byte()) < 0)
i = 0;
getbuf |= i << (8 - getlen);
getlen += 8;
}
i = getbuf;
getbuf <<= 8;
getlen -= 8;
return i >> 8;
}
static unsigned putbuf = 0;
static uchar putlen = 0;
// Output 'c' bits of code
static void Putcode(int l, unsigned c)
{
putbuf |= c >> putlen;
if ((putlen += l) >= 8)
{
write_byte(putbuf >> 8);
if ((putlen -= 8) >= 8)
{
write_byte(putbuf);
codesize += 2;
putlen -= 8;
putbuf = c << (l - putlen);
} else {
putbuf <<= 8;
++codesize;
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