ref: 35b98e0f4f5d021690beb4f274e637e327063e62
dir: /src/g72x.h/
/* * 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_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 *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 *qtab); int tandem_adjust_ulaw(int sr, int se, int y, int i, int sign, short *qtab); #endif /* !_G72X_H */