#include <iostream>
#include <fstream>
 
using namespace std ;
 
int main ()
{
	ifstream fileopen ;
	char buffer[100 ] ;
	char c ;
 
	fileopen.open ( "G00046_002_01.srf", ios :: in | ios :: out | ios :: binary ) ;
 
	if(fileopen.is_open())
	{
		fileopen.seekg(0, ios :: beg) ; // Move pointer to the beginning
		while(!fileopen.eof())
		{
			fileopen.read(buffer, 50) ;
			fileopen.seekg(4) ;
			fileopen >> c ;        // Just to check the file read correctly 
			cout << c << endl ;
 
                       // Now I want to read the next 4 bytes here
 
		}
		fileopen.close() ;
	}
 
	else
	{
		cout << "Unable to open the file\n" ;
	}
 
 
	cin.get() ;
	return 0 ;
}

while( fileopen >> c)
{
   // blabla
}