huffman.h

常用的无损压缩算法源代码

/* = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = */

/*         H U F F M A N   C O D E   I M P L E M E N T A T I O N       */

/* = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = */
/*     > > > > >    ANSI C version  2.05  -  05/30/95    < < < < <     */

/*   Amir Said - [e-mail]                            */
/*   Faculty of Electrical Engineering                                 */
/*   University of Campinas (UNICAMP) - Campinas, SP 13081, Brazil     */

/*   William A. Pearlman - [e-mail]                       */
/*   Dept. of Electrical, Computer, and Systems Engineering            */
/*   Rensselaer Polytechnic Institute - Troy, NY 12180, USA            */


/* - - Inclusion - - - - - - - - - - - - - - - - - - - - - - - - - - - */

#include <stdlib.h>
#include <stdio.h>


/* - - Data types  - - - - - - - - - - - - - - - - - - - - - - - - - - */

typedef struct {

  FILE * out_file;
  int bit_buffer, bit_index, nsb, shift, nrep;
  int * code, * length, * tree[2];
  long byte_counter;

} Encoder;


typedef struct {

  FILE * in_file;
  int bit_buffer, bit_index, nsb, shift, nrep, nodes;
  int * trans_0, * trans_1;
  long byte_counter;

} Decoder;


/* - - Interface to < Encoder >  - - - - - - - - - - - - - - - - - - - */


void Start_Encoder(Encoder * E, char * file_name);

void Write_Code(Encoder * E, int numb_symbols, long frequency[]);

void Write_Bit(Encoder * E, int bit);

void Write_Bits(Encoder * E, int bits, int word);

void Write_Symbol(Encoder * E, int symb);

long Bytes_Used(Encoder * E);

long Stop_Encoder(Encoder * E);


/* - - Interface to < Decoder >  - - - - - - - - - - - - - - - - - - - */


void Start_Decoder(Decoder * D, char * file_name);

int Read_Code(Decoder * E);

int Read_Bit(Decoder * E);

int Read_Bits(Decoder * E, int bits);

int Read_Symbol(Decoder * E);

long Bytes_Read(Decoder * E);

void Stop_Decoder(Decoder * E);


/* = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = */

/* end of file < huffman.h > */