/****************************************************************************
 * MODEM for the Real-time BBC Codec/Modem                                  *
 ****************************************************************************
 * William L. Bahn                                                          *
 * Academy Center for Information Security                                  *
 * Department of Computer Science                                           *
 * United States Air Force Academy                                          *
 * USAFA, CO 80840                                                          *
 ****************************************************************************
 * FILE:............ modem.h                                                *
 * DATE CREATED:.... 06 SEP 07                                              *
 * DATE MODIFIED:... 06 SEP 07                                              *
 ****************************************************************************
 *
 * REVISION HISTORY
 *
 ****************************************************************************
 *
 * DESCRIPTION
 *
 * The modem converts baseband signal data to/from packet data.
 *
 */

#ifndef MODEMdotH
#define MODEMdotH

//------------------------------------------------------------------------
// REQUIRED INCLUDES
//------------------------------------------------------------------------

#include <time.h>  // clock_t

#include "config.h"
#include "source.h"
#include "buffer.h"
#include "sink.h"
#include "dirtyd.h"

//------------------------------------------------------------------------
// STRUCTURE DECLARATIONS
//------------------------------------------------------------------------

typedef struct MODEM MODEM;

//------------------------------------------------------------------------
// STRUCTURE DEFINITIONS
//------------------------------------------------------------------------

// NOTE: Normally the structure definition would be in the *.c file to make 
// the structure members inaccessible to outside functions except through
// public function calls. But for the real-time code it has been decided 
// to make the structure members directly visible to the functions that
// manipulate them.

struct MODEM
{
	// Derived quantities
	DWORD jitter_samples;
	double alpha;
	double t_hi, t_lo;

	// State information
	DWORD state;
	double integrator;
	SDWORD stamp;
};

//------------------------------------------------------------------------
// PUBLIC FUNCTION PROTOTYPES
//------------------------------------------------------------------------

MODEM *MODEM_Del(MODEM *p);
MODEM *MODEM_New(CONFIG *c, DWORD *errcode);
void Modulate(CONFIG *c, BUFFER *buffer, MODEM *modem, SINK *sink);
void Demodulate(CONFIG *c, SOURCE *source, MODEM *modem, BUFFER *buf);

//------------------------------------------------------------------------
#endif