/*
 * This source code is a product of Sun Microsystems, Inc. and is provided
 * for unrestricted use.  Users may copy or modify this source code without
 * charge.
 *
 * SUN SOURCE CODE IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING
 * THE WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
 *
 * Sun source code is provided with no support and without any obligation on
 * the part of Sun Microsystems, Inc. to assist in its use, correction,
 * modification or enhancement.
 *
 * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
 * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY THIS SOFTWARE
 * OR ANY PART THEREOF.
 *
 * In no event will Sun Microsystems, Inc. be liable for any lost revenue
 * or profits or other special, indirect and consequential damages, even if
 * Sun has been advised of the possibility of such damages.
 *
 * Sun Microsystems, Inc.
 * 2550 Garcia Avenue
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 */

/*
 * g72x.h
 *
 * Header file for CCITT conversion routines.
 *
 */

#include "math.h"

#ifndef _G72X_H
#define	_G72X_H

#define	AUDIO_ENCODING_ULAW	(1)	/* ISDN u-law */
#define	AUDIO_ENCODING_ALAW	(2)	/* ISDN A-law */
#define	AUDIO_ENCODING_LINEAR	(3)	/* PCM 2's-complement (0-center) */

/*
 * The following is the definition of the state structure
 * used by the G.721/G.723 encoder and decoder to preserve their internal
 * state between successive calls.  The meanings of the majority
 * of the state structure fields are explained in detail in the
 * CCITT Recommendation G.721.  The field names are essentially indentical
 * to variable names in the bit level description of the coding algorithm
 * included in this Recommendation.
 */
typedef struct g726_state_s {
	long yl;	/* Locked or steady state step size multiplier. */
	int yu;		/* Unlocked or non-steady state step size multiplier. */
	int dms;	/* Short term energy estimate. */
	int dml;	/* Long term energy estimate. */
	int ap;		/* Linear weighting coefficient of 'yl' and 'yu'. */

	int a[2];	/* Coefficients of pole portion of prediction filter. */
	int b[6];	/* Coefficients of zero portion of prediction filter. */
	int pk[2];	/* Signs of previous two samples of a partially
				 * reconstructed signal. */
	short dq[6];/* int here fails in newupdate on encode!
				 * Previous 6 samples of the quantized difference
				 * signal represented in an internal floating point
				 * format.
				 */
	int sr[2];	/* Previous 2 samples of the quantized difference
				 * signal represented in an internal floating point
				 * format. */
	int td;		/* delayed tone detect, new in 1988 version */
} g726_state;

/* External function definitions. */

void g726_init_state( g726_state *);

int g726_32_encoder(
		int sample,
		int in_coding,
		 g726_state *state_ptr);
int g726_32_decoder(
		int code,
		int out_coding,
		 g726_state *state_ptr);
int g726_16_encoder(
        int sample,
        int in_coding,
         g726_state *state_ptr);
int g726_16_decoder(
        int code,
        int out_coding,
         g726_state *state_ptr);
int g726_24_encoder(
		int sample,
		int in_coding,
		 g726_state *state_ptr);
int g726_24_decoder(
		int code,
		int out_coding,
		 g726_state *state_ptr);
int g726_40_encoder(
		int sample,
		int in_coding,
		 g726_state *state_ptr);
int g726_40_decoder(
		int code,
		int out_coding,
		 g726_state *state_ptr);

#endif /* !_G72X_H */

