#ifndef _BITIO_H
#define _BITIO_H

#include <stdlib.h>
#include "h261vlc.h"
#include "except.h"


struct huffman_elem {
	int symbol;
	int prob;
	huffman_elem() {symbol = 0; prob = 0;}
};

struct tree_node {
	tree_node *left, *right;  /* Left branch, right branch */
 	tree_node *top;		/* Root */
	huffman_elem huf;
	tree_node() { left = right = top = 0;}
};



/* Bidirectional class for bit input/output operations: 
   Either for read or write but not both */
class bit_io {
private: 
	int  valid_rbits;
	int  valid_wbits;
	int buf_rbytes;
	int buf_wbytes;

	int total_rbytes;
	int total_wbytes;

	u_char curr_rbyte;
	u_char curr_wbyte;

	u_short dummy;

	u_char *read_buf;
	u_char *write_buf;

	int max_rbits;
	int max_wbytes;

	

public:
	bit_io();
	void attach_rbuf(u_char *buf, int max_bits);
	void attach_wbuf(u_char *buf, int max_bytes);

	int read_bit(void) throw (PicException_t);

	int read_bits(int len); /* Upto 32 bits */
 
	int write_bit(int bitvalue);
	int write_bits(u_char *bitstream, int numbits, int terminate=0);
	int write_bits(struct symbol_code& s, int terminate=0);

	int bit_io::write_flush(void)
		throw (PicException_t);
	void print(void); /* Debugging */
	
	int GetBufWbytes(void);
	int wflush_bits(void);
	int GetRbufBits(void);

};



int add_to_tree(tree_node *root, struct symbol_string& s);

/* 0 on success, -1 on error */
int tree_read(bit_io *input, tree_node *root, int& symbol);


#endif