g72x.h

symbian 系统下的g.723 g.723_24实现, 本源码在 series60 sdk fp2下调试通过

/*
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 * for unrestricted use.  Users may copy or modify this source code without
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 *
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 * THE WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
 *
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 * modification or enhancement.
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 * 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.
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 * or profits or other special, indirect and consequential damages, even if
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 *
 * Sun Microsystems, Inc.
 * 2550 Garcia Avenue
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 */

/*
 * g72x.h
 *
 * Header file for CCITT conversion routines.
 *
 */
#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.
 */
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.
			 */
	int td;	/* delayed tone detect, new in 1988 version */
};

#define AUDIODATAL	480
union AudioPacket
{
    struct
	{
		long  AudioID;	//2 words
		struct g72x_state Audio_state; //26 words
		int Audio_data[AUDIODATAL];
	}AP_S; 
	int Audio_data[AUDIODATAL+28]; 
};



/* External function definitions. */
#ifdef __cplusplus
extern "C"
{
#endif

	void g72x_init_state(struct g72x_state *);
	int g723_24_encoder(
		int sample,
		int in_coding,
		struct g72x_state *state_ptr);
	int g723_24_decoder(
		int code,
		int out_coding,
		struct g72x_state *state_ptr);
	
//	int  pack_output( unsigned char code, int bits, char* pOut );
//	int  unpack_input( unsigned char *code, int bits, char* pIn); 

#ifdef __cplusplus
}
#endif


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 unsigned char linear2alaw( int pcm_val );
extern int alaw2linear( unsigned char );

extern unsigned char linear2ulaw( int pcm_val );
extern short ulaw2linear( unsigned char u_val );

extern unsigned char alaw2ulaw( unsigned char aval );
extern unsigned char ulaw2alaw( unsigned char uval );
/*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);

#endif /* !_G72X_H */