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dir: /src/speech/g72x.h/

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/*************************************************************************/
/*                                                                       */
/*                  Language Technologies Institute                      */
/*                     Carnegie Mellon University                        */
/*                        Copyright (c) 2010                             */
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/*  THIS SOFTWARE.                                                       */
/*                                                                       */
/*************************************************************************/
/*             Author:  Alan W Black (awb@cs.cmu.edu)                    */
/*               Date:  March 2001                                       */
/*************************************************************************/
/*                                                                       */
/*  Minor fixes to make it properly ansi and fit into cst                */
/*                                                                       */
/*************************************************************************/
/*
 * 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
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 * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
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 * OR ANY PART THEREOF.
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 * In no event will Sun Microsystems, Inc. be liable for any lost revenue
 * or profits or other special, indirect and consequential damages, even if
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 * Sun Microsystems, Inc.
 * 2550 Garcia Avenue
 * Mountain View, California  94043
 */

/*
 * g72x.h
 *
 * Header file for CCITT conversion routines.
 *
 */
#ifndef _G72X_H
#define	_G72X_H

#include "cst_wave.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.
 */
struct g72x_state {
	long yl;	/* Locked or steady state step size multiplier. */
	short yu;	/* Unlocked or non-steady state step size multiplier. */
	short dms;	/* Short term energy estimate. */
	short dml;	/* Long term energy estimate. */
	short ap;	/* Linear weighting coefficient of 'yl' and 'yu'. */

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

/* External function definitions. */

extern void g72x_init_state(struct g72x_state *);
extern int g721_encoder(
		int sample,
		int in_coding,
		struct g72x_state *state_ptr);
extern int g721_decoder(
		int code,
		int out_coding,
		struct g72x_state *state_ptr);
extern int g723_24_encoder(
		int sample,
		int in_coding,
		struct g72x_state *state_ptr);
extern int g723_24_decoder(
		int code,
		int out_coding,
		struct g72x_state *state_ptr);
extern int g723_40_encoder(
		int sample,
		int in_coding,
		struct g72x_state *state_ptr);
extern int g723_40_decoder(
		int code,
		int out_coding,
		struct g72x_state *state_ptr);

/* Internal functions */
int g72x_predictor_zero(struct g72x_state *state_ptr);
int g72x_predictor_pole(struct g72x_state *state_ptr);
int g72x_step_size(struct g72x_state *state_ptr);
int
g72x_quantize(
	int		d,	/* Raw difference signal sample */
	int		y,	/* Step size multiplier */
	short		*table,	/* quantization table */
	int		size);	/* table size of short integers */
int
g72x_reconstruct(
	int		sign,	/* 0 for non-negative value */
	int		dqln,	/* G.72x codeword */
	int		y);	/* Step size multiplier */
void
g72x_update(
	int		code_size,	/* distinguish 723_40 with others */
	int		y,		/* quantizer step size */
	int		wi,		/* scale factor multiplier */
	int		fi,		/* for long/short term energies */
	int		dq,		/* quantized prediction difference */
	int		sr,		/* reconstructed signal */
	int		dqsez,		/* difference from 2-pole predictor */
	struct g72x_state *state_ptr);  /* coder state pointer */



#endif /* !_G72X_H */