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/* 
   ITU-T G.729 Annex C+ - Reference C code for floating point 
                         implementation of G.729 Annex C+ 
                         (integration of Annexes B, D and E) 
                         Version 2.1 of October 1999 
*/ 
/* 
 File : DTX.H 
*/ 
 
/*--------------------------------------------------------------------------* 
 * Prototypes for DTX/CNG                                                   * 
 *--------------------------------------------------------------------------*/ 
 
/* Encoder DTX/CNG functions */ 
void init_cod_cng(void); 
void cod_cng( 
  FLOAT *exc,          /* (i/o) : excitation array                     */ 
  int pastVad,         /* (i)   : previous VAD decision                */ 
  FLOAT *lsp_old_q,    /* (i/o) : previous quantized lsp               */ 
    FLOAT *old_A,          /* (i/o) : last stable filter LPC coefficients  */ 
    FLOAT *old_rc,         /* (i/o) : last stable filter Reflection coefficients.*/ 
  FLOAT *Aq,           /* (o)   : set of interpolated LPC coefficients */ 
  int *ana,            /* (o)   : coded SID parameters                 */ 
  FLOAT freq_prev[MA_NP][M], 
                       /* (i/o) : previous LPS for quantization        */ 
  INT16 *seed          /* (i/o) : random generator seed                */ 
); 
void update_cng( 
  FLOAT *r,         /* (i) :   frame autocorrelation               */ 
  int Vad           /* (i) :   current Vad decision                */ 
); 
 
/* SID gain Quantization */ 
void qua_Sidgain( 
  FLOAT *ener,     /* (i)   array of energies                   */ 
  int nb_ener,     /* (i)   number of energies or               */ 
  FLOAT *enerq,    /* (o)   decoded energies in dB              */ 
  int *idx         /* (o)   SID gain quantization index         */ 
); 
 
/* CNG excitation generation */ 
void calc_exc_rand( 
  FLOAT cur_gain,      /* (i)   :   target sample gain                 */ 
  FLOAT *exc,          /* (i/o) :   excitation array                   */ 
  INT16 *seed,         /* (i)   :   current Vad decision               */ 
  int flag_cod         /* (i)   :   encoder/decoder flag               */ 
); 
 
/* SID LSP Quantization */ 
void get_freq_prev(FLOAT x[MA_NP][M]); 
void update_freq_prev(FLOAT x[MA_NP][M]); 
void get_decfreq_prev(FLOAT x[MA_NP][M]); 
void update_decfreq_prev(FLOAT x[MA_NP][M]); 
 
/* Decoder CNG generation */ 
void init_dec_cng(void); 
void dec_cng( 
  int past_ftyp,       /* (i)   : past frame type                      */ 
  FLOAT sid_sav,       /* (i)   : energy to recover SID gain           */ 
  int *parm,           /* (i)   : coded SID parameters                 */ 
  FLOAT *exc,          /* (i/o) : excitation array                     */ 
  FLOAT *lsp_old,      /* (i/o) : previous lsp                         */ 
  FLOAT *A_t,          /* (o)   : set of interpolated LPC coefficients */ 
  INT16 *seed,         /* (i/o) : random generator seed                */ 
  FLOAT freq_prev[MA_NP][M] 
                        /* (i/o) : previous LPS for quantization        */ 
); 
int read_frame(FILE *f_serial, int *parm); 
 
/*--------------------------------------------------------------------------* 
 * Constants for DTX/CNG                                                    * 
 *--------------------------------------------------------------------------*/ 
 
/* DTX constants */ 
#define FLAG_COD        1 
#define FLAG_DEC        0 
#define INIT_SEED       (INT16)11111 
#define FR_SID_MIN      3 
#define NB_SUMACF       3 
#define NB_CURACF       2 
#define NB_GAIN         2 
#define THRESH1         (FLOAT)1.1481628 
#define THRESH2         (FLOAT)1.0966466 
#define A_GAIN0         (FLOAT)0.875 
 
#define SIZ_SUMACF      (NB_SUMACF * MP1) 
#define SIZ_ACF         (NB_CURACF * MP1) 
#define A_GAIN1         ((FLOAT)1. - A_GAIN0) 
 
#define MIN_ENER        (FLOAT)0.1588489319   /* <=> - 8 dB      */ 
 
/* CNG excitation generation constant */ 
                                           /* alpha = 0.5 */ 
#define NORM_GAUSS      (FLOAT)3.16227766  /* sqrt(40)xalpha */ 
#define K0              (FLOAT)3.          /* 4 x (1 - alpha ** 2) */ 
#define G_MAX           (FLOAT)5000.