/* YUNTAI KYONGAdvanced Internet Serviceterm project*/#include <assert.h>		// assert()#include <stdio.h>		// FILE#include <stdlib.h>		// exit()#include <memory.h>		// memcpy()#include "fileStream.h"extern void error(char*);//////////////////////////////////////////////////////////////		Constructor//		@param//			inputFile: set file streamfileStream::fileStream(FILE *inputFile){	assert( inputFile != NULL );	this->inputFile = inputFile;	m_b_Mark = 0;	bytesToRead = 0;	m_cur_pos   = 0;	m_cur_file_pos = 0;	get_next_data();}int fileStream::getSizeFromMark(){	return (m_cur_file_pos-m_mark_pos);}voidfileStream::mark(){		assert(BYTEALIGNED());	assert(m_b_Mark == 0);	m_mark_pos = m_cur_file_pos;	m_b_Mark = 1;}intfileStream::load(unsigned  char *outBuf){		static __int64 totalLoadedBytes = 0;	assert(BYTEALIGNED());	assert(m_b_Mark == 1);	fpos_t current_pos;		int size = m_cur_file_pos - m_mark_pos;		fgetpos( inputFile, &current_pos);		fseek( inputFile, SEEK_SET , m_mark_pos );	fread( outBuf, 1, size, inputFile );		fsetpos( inputFile,  &current_pos );		fpos_t current_pos2;	fgetpos( inputFile, &current_pos2 );	assert( current_pos==current_pos2 );	/*	printf("mark: %d\n", m_mark_pos );	printf("cur: %d\n", m_cur_file_pos );	printf("load: %d bytes\n",  size );	*/	totalLoadedBytes+= size;	printf("total: %d bytes\n", totalLoadedBytes );	m_b_Mark = 0;	return size;}voidfileStream::rewind(){		assert(BYTEALIGNED());	assert(m_b_Mark == 1);	printf("rewind!!!!");	cur_byte	= m_mark;	m_cur_pos	= m_mark_pos;	m_b_Mark = 0;}//////////////////////////////////////////////////////////////		get_next_data//		@description//			read data from file and fill it into the//ternal bufferintfileStream::get_next_data(void){		if(!bytesToRead) 	{			bytesToRead = fread(buffer, 1, BUFFER_SIZE, inputFile);		if( bytesToRead == 0 )			return -2;		m_cur_pos = 0;		cur_byte = buffer;		cur_bit = 7;	}	return 1;}//////////////////////////////////////////////////////////////		get_bits//		@param//			bits_left: number of bits to be read//		@return//			Value// return next bits unsigned intfileStream::get_bits(int bits_left){	unsigned int byte, result;		result = 0;	do {		if(BYTEALIGNED() && (bits_left >= 8))        {			bits_left -= 8;			result |= get_byte() << bits_left;        }		else        {			byte = *cur_byte;			byte &= (unsigned int) 0xffffffff >> (31 - cur_bit);			if(cur_bit >= bits_left)            {				result |= byte >> (cur_bit - bits_left + 1);				cur_bit -= bits_left;				bits_left = 0;            }			else            {				result |= byte << (bits_left - cur_bit - 1);				bits_left -= cur_bit + 1;				cur_bit = 7;				cur_byte++;				m_cur_file_pos++;				m_cur_pos++;				bytesToRead--;				get_next_data();            }        }    } while(bits_left);	return result;}//////////////////////////////////////////////////////////////		get_byte//		@return//			value read/* get next byte */unsigned int fileStream::get_byte(){	unsigned int byte;	if( get_next_data() == -2 )		return -2;		if(cur_bit != 7)		error("get_byte(): Non byte aligned in get_byte.  MPEG file is corrupted");	m_cur_file_pos++;	m_cur_pos++;	byte = *cur_byte++;	bytesToRead--;	return byte;}/* check next bits are equal to given bit string */unsigned int fileStream::next_bits(int bit_count, unsigned int string){	unsigned char *ptr;	if(cur_bit != 7)	{		int j =0;		int i = 3/j;		error("Comparing non byte aligned data.  MPEG file is corrupted");	}	/* Check that we have enough data in buffer to do non destructive read */	int bytes = bit_count >> 3;		if(bytes > bytesToRead)    {			assert( bytes > bytesToRead );		printf( "bytes: %d, bytesToRead: %d\n", bytes, bytesToRead );		int ret;		memcpy( buffer, cur_byte, bytesToRead);		ret = fread(buffer+bytesToRead, 1, BUFFER_SIZE-bytesToRead,inputFile);		if( ret == 0 )		{			printf("end of file!\n");			return -2;		}		bytesToRead += ret;		printf("ret: %d, bytesToRead: %d\n", ret, bytesToRead );		cur_byte = buffer;		m_cur_pos = 0;	}		ptr = cur_byte;	do 	{		if(*ptr++ != ((string >> (bit_count -= 8)) & 255))			return 0;			} while(bit_count);	return 1;}/* return next bit */unsigned int fileStream::get_bit(){	unsigned int bit;		get_next_data();	bit = (*cur_byte >> cur_bit) & 1;		if(cur_bit == 0)    {		m_cur_file_pos++;		m_cur_pos++;		cur_byte++;		bytesToRead--;		cur_bit = 7;    }	else		cur_bit--;		return bit;}