ref: 2024869a595118d686682b38386c594c717ea5bd
dir: /src/g72x.h/
/* This source code is a product of Sun Microsystems, Inc. and is provided
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*
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*
* Sun source code is provided with no support and without any obligation on
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* modification or enhancement.
*
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* 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
/* aliases */
#define g721_decoder lsx_g721_decoder
#define g721_encoder lsx_g721_encoder
#define g723_24_decoder lsx_g723_24_decoder
#define g723_24_encoder lsx_g723_24_encoder
#define g723_40_decoder lsx_g723_40_decoder
#define g723_40_encoder lsx_g723_40_encoder
#define g72x_init_state lsx_g72x_init_state
#define predictor_pole lsx_g72x_predictor_pole
#define predictor_zero lsx_g72x_predictor_zero
#define quantize lsx_g72x_quantize
#define reconstruct lsx_g72x_reconstruct
#define step_size lsx_g72x_step_size
#define tandem_adjust_alaw lsx_g72x_tandem_adjust_alaw
#define tandem_adjust_ulaw lsx_g72x_tandem_adjust_ulaw
#define update lsx_g72x_update
#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_16_encoder(
int sample,
int in_coding,
struct g72x_state *state_ptr);
extern int g723_16_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);
int predictor_zero(struct g72x_state *state_ptr);
int predictor_pole(struct g72x_state *state_ptr);
int step_size(struct g72x_state *state_ptr);
int quantize(int d,
int y,
short const *table,
int size);
int reconstruct(int sign,
int dqln,
int y);
void update(int code_size,
int y,
int wi,
int fi,
int dq,
int sr,
int dqsez,
struct g72x_state *state_ptr);
int tandem_adjust_alaw(int sr,
int se,
int y,
int i,
int sign,
short const *qtab);
int tandem_adjust_ulaw(int sr,
int se,
int y,
int i,
int sign,
short const *qtab);
#endif /* !_G72X_H */