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/*
* 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.
*
*/
#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.
*/
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);
extern int
quantize(
int d,
int y,
short *table,
int size);
extern int reconstruct(int,int,int);void
extern update(
int code_size,
int y,
int wi,
int fi,
int dq,
int sr,
int dqsez,
struct g72x_state *state_ptr);
extern int
tandem_adjust_alaw(
int sr,
int se,
int y,
int i,
int sign,
short *qtab);
extern int
tandem_adjust_ulaw(
int sr,
int se,
int y,
int i,
int sign,
short *qtab);
extern unsigned char
linear2alaw(
int pcm_val);
extern int
alaw2linear(
unsigned char a_val);
extern unsigned char
linear2ulaw(int pcm_val);
extern int ulaw2linear( unsigned char u_val);
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);
#endif /* !_G72X_H */
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