RTL271_1/amrnb/vad1.h

/*
********************************************************************************
**-------------------------------------------------------------------------**
**                                                                         **
**     GSM AMR-NB speech codec   R98   Version 7.6.0   December 12, 2001       **
**                               R99   Version 3.3.0                       **
**                               REL-4 Version 4.1.0                       **
**                                                                         **
**-------------------------------------------------------------------------**
********************************************************************************
*
*      File             : vad1.h
*      Purpose          : Voice Activity Detection (VAD) for AMR (option 1)
*
********************************************************************************
*/
#ifndef vad1_h
#define vad1_h "$Id $"
 
/*
********************************************************************************
*                         INCLUDE FILES
********************************************************************************
*/
#include "typedef.h"
#include "cnst_vad.h"

/*
********************************************************************************
*                         LOCAL VARIABLES AND TABLES
********************************************************************************
*/

/*
********************************************************************************
*                         DEFINITION OF DATA TYPES
********************************************************************************
*/

/* state variable */
typedef struct {
   
   Word16 bckr_est[COMPLEN];    /* background noise estimate                */
   Word16 ave_level[COMPLEN];   /* averaged input components for stationary */
                                /*    estimation                            */
   Word16 old_level[COMPLEN];   /* input levels of the previous frame       */
   Word16 sub_level[COMPLEN];   /* input levels calculated at the end of
                                      a frame (lookahead)                   */
   Word16 a_data5[3][2];        /* memory for the filter bank               */
   Word16 a_data3[5];           /* memory for the filter bank               */

   Word16 burst_count;          /* counts length of a speech burst          */
   Word16 hang_count;           /* hangover counter                         */
   Word16 stat_count;           /* stationary counter                       */

   /* Note that each of the following three variables (vadreg, pitch and tone)
      holds 15 flags. Each flag reserves 1 bit of the variable. The newest
      flag is in the bit 15 (assuming that LSB is bit 1 and MSB is bit 16). */
   Word16 vadreg;               /* flags for intermediate VAD decisions     */
   Word16 pitch;                /* flags for pitch detection                */
   Word16 tone;                 /* flags for tone detection                 */
   Word16 complex_high;         /* flags for complex detection              */
   Word16 complex_low;          /* flags for complex detection              */

   Word16 oldlag_count, oldlag; /* variables for pitch detection            */
 
   Word16 complex_hang_count;   /* complex hangover counter, used by VAD    */
   Word16 complex_hang_timer;   /* hangover initiator, used by CAD          */
    
   Word16 best_corr_hp;         /* FIP filtered value Q15                   */ 

   Word16 speech_vad_decision;  /* final decision                           */
   Word16 complex_warning;      /* complex background warning               */

   Word16 sp_burst_count;       /* counts length of a speech burst incl
                                   HO addition                              */
   Word16 corr_hp_fast;         /* filtered value                           */ 
} vadState1;

/*
********************************************************************************
*                         DECLARATION OF PROTOTYPES
********************************************************************************
*/
int vad1_init (vadState1 **st);
/* initialize one instance of the pre processing state.
   Stores pointer to filter status struct in *st. This pointer has to
   be passed to vad in each call.
   returns 0 on success
 */
 
int vad1_reset (vadState1 *st);
/* reset of pre processing state (i.e. set state memory to zero)
   returns 0 on success
 */

void vad1_exit (vadState1 **st);
/* de-initialize pre processing state (i.e. free status struct)
   stores NULL in *st
 */

void vad_complex_detection_update (vadState1 *st,      /* i/o : State struct     */
                                   Word16 best_corr_hp /* i   : best Corr Q15    */
                                   );

void vad_tone_detection (vadState1 *st, /* i/o : State struct            */
                         Word32 t0,     /* i   : autocorrelation maxima  */
                         Word32 t1      /* i   : energy                  */
                         );

void vad_tone_detection_update (
                vadState1 *st,             /* i/o : State struct              */
                Word16 one_lag_per_frame   /* i   : 1 if one open-loop lag is
                                              calculated per each frame,
                                              otherwise 0                     */
                );

void vad_pitch_detection (vadState1 *st,  /* i/o : State struct                  */
                          Word16 lags[]   /* i   : speech encoder open loop lags */
                          );

Word16 vad1 (vadState1 *st,  /* i/o : State struct                      */
            Word16 in_buf[]  /* i   : samples of the input frame 
                                inbuf[159] is the very last sample,
                                incl lookahead                          */
            );
#endif