g72x.h

基于TI的DSP的G726_CODEC

/*
 * 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
 * Mountain View, California  94043
 */

/*
 * g72x.h
 *
 * Header file for CCITT conversion routines.
 *
 */
static short power2[15] = {1, 2, 4, 8, 0x10, 0x20, 0x40, 0x80,
			0x100, 0x200, 0x400, 0x800, 0x1000, 0x2000, 0x4000};  
			
#ifndef _G72X_H
#define	_G72X_H

/*#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 predictor_zero(struct g72x_state *state_ptr); */
/*extern int predictor_pole(struct g72x_state *state_ptr); */
extern int step_size(struct g72x_state *state_ptr);
extern int quantize(int	d, int y, short *table);
extern int reconstruct(int sign, int dqln, int y);
extern void update(int code_size, long y, long wi, int fi, int dq, int sr, int dqsez, struct g72x_state *state_ptr);


extern int g721_encoder(
		int sample,
		struct g72x_state *state_ptr);
extern int g721_decoder(
		int code,
		struct g72x_state *state_ptr);                                                                                                                                                                        

/*qune set inline */
#ifdef _INLINE
#define __INLINE static inline
#else
#define __INLINE
#endif

__INLINE int fmult(int	an,int	srn);
__INLINE int quan7(int	val,short	*table);
__INLINE int quan16(int	val,short	*table);

#ifdef _INLINE
/*
 * fmult()
 *
 * returns the integer product of the 14-bit integer "an" and
 * "floating point" representation (4-bit exponent, 6-bit mantessa) "srn".
 */
static inline int
fmult(
	int		an,
	int		srn)
{
	short		anmag, anexp, anmant;
	long		wanexp/*, wanmag*/, wanmant;
	short		retval;

	anmag = (an > 0) ? an : ((-an) & 0x1FFF);
	anexp = quan16(anmag, power2) - 6;
	anmant = (anmag == 0) ? 32 :
	    (anexp >= 0) ? anmag >> anexp : anmag << -anexp;
	wanexp = anexp + ((srn >> 6) & 0xF) - 13;

	wanmant = (anmant * (srn & 077) + 0x30) >> 4;
	retval = (wanexp >= 0) ? ((wanmant << wanexp) & 0x7FFF) :
	    (wanmant >> -wanexp);

	return (((an ^ srn) < 0) ? -retval : retval);
}


static inline int quan7(int	val,short	*table)
{
	int		i;                                       


	for (i = 0; i < size; i++)
		if (val < *table++)
			break;
	return (i);
}






#endif  /* INLINE */
#undef __INLINE	


#endif /* !_G72X_H */