dtx.inc

来自「基于ADSP的G.729语音编解码程序」· INC 代码 · 共 28 行

/*-------------------------------------------------------------------------*
* Constants for DTX/CNG                                                    *
* $$01/10/2000 rejustified the tables used in audio codec                  *
*--------------------------------------------------------------------------*/
#define FLAG_COD        1
#define FLAG_DEC        0
#define INIT_SEED       11111
#define FR_SID_MIN      3
#define NB_SUMACF       3
#define NB_CURACF       2
#define NB_GAIN         2
#define R_LSFQ          10
#define FRAC_THRESH1    4855
#define FRAC_THRESH2    3161
#define A_GAIN0         28672
#define SIZ_SUMACF      (NB_SUMACF * MP1)
#define SIZ_ACF         (NB_CURACF * MP1)
#define A_GAIN1         4096    /* 32768L - A_GAIN0 */
#define RATE_8000       0x0002      /* Full rate  (8000 bit/s)       */
#define RATE_SID        0x0001      /* SID                           */
#define RATE_0          0x0000      /* 0 bit/s rate                  */
 
/* CNG excitation generation constant while alpha = 0.5                   */
#define FRAC1           19043           /* (sqrt(40)xalpha/2 - 1) * 32768 */
#define K0              24576           /* (1 - alpha ** 2) in Q15        */
#define G_MAX           5000