utils/wxMMedia2/lib/g72x.h

   1 /*
   2  * This source code is a product of Sun Microsystems, Inc. and is provided
   3  * for unrestricted use.  Users may copy or modify this source code without
   4  * charge.
   5  *
   6  * SUN SOURCE CODE IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING
   7  * THE WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
   8  * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
   9  *
  10  * Sun source code is provided with no support and without any obligation on
  11  * the part of Sun Microsystems, Inc. to assist in its use, correction,
  12  * modification or enhancement.
  13  *
  14  * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
  15  * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY THIS SOFTWARE
  16  * OR ANY PART THEREOF.
  17  *
  18  * In no event will Sun Microsystems, Inc. be liable for any lost revenue
  19  * or profits or other special, indirect and consequential damages, even if
  20  * Sun has been advised of the possibility of such damages.
  21  *
  22  * Sun Microsystems, Inc.
  23  * 2550 Garcia Avenue
  24  * Mountain View, California  94043
  25  */
  26
  27 /*
  28  * g72x.h
  29  *
  30  * Header file for CCITT conversion routines.
  31  *
  32  */
  33 #ifndef _G72X_H
  34 #define _G72X_H
  35
  36 #define AUDIO_ENCODING_ULAW     (1)     /* ISDN u-law */
  37 #define AUDIO_ENCODING_ALAW     (2)     /* ISDN A-law */
  38 #define AUDIO_ENCODING_LINEAR   (3)     /* PCM 2's-complement (0-center) */
  39
  40 /*
  41  * The following is the definition of the state structure
  42  * used by the G.721/G.723 encoder and decoder to preserve their internal
  43  * state between successive calls.  The meanings of the majority
  44  * of the state structure fields are explained in detail in the
  45  * CCITT Recommendation G.721.  The field names are essentially indentical
  46  * to variable names in the bit level description of the coding algorithm
  47  * included in this Recommendation.
  48  */
  49 struct g72x_state {
  50         long yl;        /* Locked or steady state step size multiplier. */
  51         short yu;       /* Unlocked or non-steady state step size multiplier. */
  52         short dms;      /* Short term energy estimate. */
  53         short dml;      /* Long term energy estimate. */
  54         short ap;       /* Linear weighting coefficient of 'yl' and 'yu'. */
  55
  56         short a[2];     /* Coefficients of pole portion of prediction filter. */
  57         short b[6];     /* Coefficients of zero portion of prediction filter. */
  58         short pk[2];    /*
  59                          * Signs of previous two samples of a partially
  60                          * reconstructed signal.
  61                          */
  62         short dq[6];    /*
  63                          * Previous 6 samples of the quantized difference
  64                          * signal represented in an internal floating point
  65                          * format.
  66                          */
  67         short sr[2];    /*
  68                          * Previous 2 samples of the quantized difference
  69                          * signal represented in an internal floating point
  70                          * format.
  71                          */
  72         char td;        /* delayed tone detect, new in 1988 version */
  73 };
  74
  75 /* External function definitions. */
  76
  77 extern unsigned char linear2alaw (int pcm_val); /* 2's complement (16-bit range) */
  78 extern int alaw2linear (unsigned char a_val);
  79 extern unsigned char linear2ulaw (int pcm_val); /* 2's complement (16-bit range) */
  80 extern int ulaw2linear (unsigned char u_val);
  81 extern int predictor_zero (struct g72x_state *state_ptr);
  82 extern int predictor_pole (struct g72x_state *state_ptr);
  83 extern int step_size (struct g72x_state *state_ptr);
  84 extern int quantize (int d, int y, short *table, int size);
  85 extern int reconstruct (int sign, int dqln, int y);
  86
  87 extern void update
  88     ( int code_size, int y, int wi, int fi, int dq
  89         , int sr, int dqsez, struct g72x_state *state_ptr);
  90
  91 int tandem_adjust_alaw
  92     (int sr, int se, int y, int i, int sign, short *qtab);
  93
  94 int tandem_adjust_ulaw
  95     (int sr, int se, int y, int i, int sign, short *qtab);
  96
  97 extern void g72x_init_state (struct g72x_state *);
  98 extern int g721_encoder(
  99                 int sample,
 100                 int in_coding,
 101                 struct g72x_state *state_ptr);
 102 extern int g721_decoder(
 103                 int code,
 104                 int out_coding,
 105                 struct g72x_state *state_ptr);
 106 extern int g723_24_encoder(
 107                 int sample,
 108                 int in_coding,
 109                 struct g72x_state *state_ptr);
 110 extern int g723_24_decoder(
 111                 int code,
 112                 int out_coding,
 113                 struct g72x_state *state_ptr);
 114 extern int g723_40_encoder(
 115                 int sample,
 116                 int in_coding,
 117                 struct g72x_state *state_ptr);
 118 extern int g723_40_decoder(
 119                 int code,
 120                 int out_coding,
 121                 struct g72x_state *state_ptr);
 122
 123 #endif /* !_G72X_H */