[439] | 1 | /**************************************************************************
|
---|
| 2 | *
|
---|
| 3 | * huffman.h -- Huffman coding functions
|
---|
| 4 | * Copyright (C) 1994 Neil Sharman
|
---|
| 5 | *
|
---|
| 6 | * This program is free software; you can redistribute it and/or modify
|
---|
| 7 | * it under the terms of the GNU General Public License as published by
|
---|
| 8 | * the Free Software Foundation; either version 2 of the License, or
|
---|
| 9 | * (at your option) any later version.
|
---|
| 10 | *
|
---|
| 11 | * This program is distributed in the hope that it will be useful,
|
---|
| 12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of
|
---|
| 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
---|
| 14 | * GNU General Public License for more details.
|
---|
| 15 | *
|
---|
| 16 | * You should have received a copy of the GNU General Public License
|
---|
| 17 | * along with this program; if not, write to the Free Software
|
---|
| 18 | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
|
---|
| 19 | *
|
---|
| 20 | * $Id: huffman.h 9596 2005-04-07 05:06:26Z kjdon $
|
---|
| 21 | *
|
---|
| 22 | **************************************************************************/
|
---|
| 23 |
|
---|
| 24 | #ifndef H_HUFFMAN
|
---|
| 25 | #define H_HUFFMAN
|
---|
| 26 |
|
---|
| 27 | #include "sysfuncs.h"
|
---|
| 28 |
|
---|
| 29 | #include "filestats.h"
|
---|
| 30 |
|
---|
| 31 |
|
---|
| 32 | #define MAX_HUFFCODE_LEN 31
|
---|
| 33 |
|
---|
| 34 | typedef struct huff_data
|
---|
| 35 | {
|
---|
| 36 | int num_codes;
|
---|
| 37 | int mincodelen;
|
---|
| 38 | int maxcodelen;
|
---|
| 39 | int lencount[MAX_HUFFCODE_LEN + 1];
|
---|
| 40 | unsigned long min_code[MAX_HUFFCODE_LEN + 1];
|
---|
| 41 | char *clens;
|
---|
| 42 | }
|
---|
| 43 | huff_data;
|
---|
| 44 |
|
---|
| 45 |
|
---|
| 46 | huff_data *Generate_Huffman_Data (int num, long *freqs, huff_data * data,
|
---|
| 47 | u_long * mem);
|
---|
| 48 |
|
---|
| 49 | unsigned long *Generate_Huffman_Codes (huff_data * data, u_long * mem);
|
---|
| 50 |
|
---|
| 51 | unsigned long **Generate_Huffman_Vals (huff_data * data, u_long * mem);
|
---|
| 52 |
|
---|
| 53 | int Write_Huffman_Data (FILE * f, huff_data * hd);
|
---|
| 54 |
|
---|
| 55 | int Read_Huffman_Data (FILE * f, huff_data * hd, u_long * mem, u_long * disk);
|
---|
| 56 |
|
---|
| 57 | int F_Read_Huffman_Data (File * f, huff_data * hd, u_long * mem, u_long * disk);
|
---|
| 58 |
|
---|
| 59 | /* Calculate the number of bits required to code the data with the
|
---|
| 60 | specified frequencies. Normally freqs and counts should point to
|
---|
| 61 | the same array. */
|
---|
| 62 | double Calculate_Huffman_Size (int num, long *freqs, long *counts);
|
---|
| 63 |
|
---|
| 64 |
|
---|
| 65 |
|
---|
| 66 | #define HUFF_ENCODE(x, codes, lens) \
|
---|
| 67 | do { \
|
---|
| 68 | register int __i; \
|
---|
| 69 | register int __clen = (lens)[x]; \
|
---|
| 70 | register unsigned long __code = (codes)[x]; \
|
---|
[9596] | 71 | for (__i=__clen-1; __i>=0; --__i) \
|
---|
[439] | 72 | ENCODE_BIT((__code >> __i) & 1); \
|
---|
| 73 | } while(0)
|
---|
| 74 |
|
---|
| 75 | #define HUFF_ENCODE_L(x, codes, lens, count) \
|
---|
| 76 | do { \
|
---|
| 77 | HUFF_ENCODE(x, codes, lens); \
|
---|
| 78 | (count) += (lens)[x]; \
|
---|
| 79 | } while(0)
|
---|
| 80 |
|
---|
| 81 |
|
---|
| 82 | #define HUFF_DECODE(x, mcodes, values) \
|
---|
| 83 | do { \
|
---|
| 84 | register unsigned long *__min_code = (mcodes); \
|
---|
| 85 | register unsigned long *__mclen = __min_code; \
|
---|
| 86 | register unsigned long **__values = (values); \
|
---|
| 87 | register unsigned long __code = 0; \
|
---|
| 88 | do \
|
---|
| 89 | { \
|
---|
| 90 | DECODE_ADD(__code); \
|
---|
| 91 | } \
|
---|
| 92 | while (__code < *++__mclen); \
|
---|
| 93 | (x) = __values[__mclen - __min_code][__code - *__mclen]; \
|
---|
| 94 | } while(0);
|
---|
| 95 |
|
---|
| 96 |
|
---|
| 97 | #define HUFF_DECODE_L(x, mcodes, values, count) \
|
---|
| 98 | do { \
|
---|
| 99 | register unsigned long *__min_code = (mcodes); \
|
---|
| 100 | register unsigned long *__mclen = __min_code; \
|
---|
| 101 | register unsigned long **__values = (values); \
|
---|
| 102 | register unsigned long __code = 0; \
|
---|
| 103 | do \
|
---|
| 104 | { \
|
---|
| 105 | DECODE_ADD(__code); \
|
---|
| 106 | (count)++; \
|
---|
| 107 | } \
|
---|
| 108 | while (__code < *++__mclen); \
|
---|
| 109 | (x) = __values[__mclen - __min_code][__code - *__mclen]; \
|
---|
| 110 | } while(0);
|
---|
| 111 |
|
---|
| 112 |
|
---|
| 113 |
|
---|
| 114 | #endif
|
---|