code: int read_frame_data(int bytesize) throws BitstreamException
  	{
   		int	numread = 0;
  		numread = readFully(frame_bytes, 0, bytesize);
  		framesize = bytesize;
  		wordpointer = -1;
  	    bitindex = -1;
  	    return numread;
  	}
docs: Reads the data for the next frame. The frame is not parsed
  until parse frame is called.