arith.h

来自「压缩包里包含算术码压缩和解压到源代码」· C头文件 代码 · 共 45 行

/* this is the header file for arith.c, with shorter integer precision */

typedef struct  {
    FILE *file;
    unsigned char mask;
    int rack;
    int pacifier_counter;
} BIT_FILE;

/*
 * The SYMBOL structure is what is used to define a symbol in
 * arithmetic coding terms.  A symbol is defined as a range between
 * 0 and 1.  Since we are using integer math, instead of using 0 and 1
 * as our end points, we have an integer scale.  The low_count and
 * high_count define where the symbol falls in the range.
 */


typedef struct {
    unsigned short int low_count;
    unsigned short int high_count;
    unsigned short int scale;
} SYMBOL;



BIT_FILE     *OpenOutputBitFile( char *name );
void          OutputBit( BIT_FILE *bit_file, int bit );
void          CloseOutputBitFile( BIT_FILE *bit_file );
void initialize_arithmetic_encoder( void );
int encode_symbol( BIT_FILE *stream, SYMBOL *s );
void flush_arithmetic_encoder( BIT_FILE *stream );

BIT_FILE     *OpenInputBitFile( char *name );
void          CloseInputBitFile( BIT_FILE *bit_file );
int           InputBit( BIT_FILE *bit_file );
short int get_current_count( SYMBOL *s );
int convert_symbol_to_int(short int count, SYMBOL *s, short int *totals, int num_codeword);
int initialize_arithmetic_decoder( BIT_FILE *stream );
int remove_symbol_from_stream( BIT_FILE *stream, SYMBOL *s );
int arith_encode(BIT_FILE *OutBitp, unsigned short int *esti_prob, 
                       int num_codeword, int cur_index);
int arith_decode(BIT_FILE *InBitp, SYMBOL *cs, unsigned short int *esti_prob, 
                       int num_codeword, short int *totals);