/*
********************************************************************************
*
*      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             : c_g_aver.h
*      Purpose          : Background noise source charateristic detector (SCD)
*
********************************************************************************
*/
#ifndef c_g_aver_h
#define c_g_aver_h "$Id $"
 
/*
********************************************************************************
*                         INCLUDE FILES
********************************************************************************
*/
#include "typedef.h"
#include "mode.h"
#include "cnst.h"

/*
********************************************************************************
*                         LOCAL VARIABLES AND TABLES
********************************************************************************
*/
#define L_CBGAINHIST 7

/*
********************************************************************************
*                         DEFINITION OF DATA TYPES
********************************************************************************
*/
typedef struct{
   /* history vector of past synthesis speech energy */
   Word16 cbGainHistory[L_CBGAINHIST];
   
   /* state flags */
   Word16 hangVar;       /* counter; */
   Word16 hangCount;     /* counter; */

} Cb_gain_averageState;
 
/*
********************************************************************************
*                         DECLARATION OF PROTOTYPES
********************************************************************************
*/
/*
**************************************************************************
*
*  Function    : Cb_gain_average_init
*  Purpose     : Allocates initializes state memory
*  Description : Stores pointer to filter status struct in *st. This
*                pointer has to be passed to Cb_gain_average in each call.
*  Returns     : 0 on success
*
**************************************************************************
*/
Word16 Cb_gain_average_init (Cb_gain_averageState **st);
 
/*
**************************************************************************
*
*  Function    : Cb_gain_average_reset
*  Purpose     : Resets state memory
*  Returns     : 0 on success
*
**************************************************************************
*/
Word16 Cb_gain_average_reset (Cb_gain_averageState *st);
 
/*
**************************************************************************
*
*  Function    : Cb_gain_average_exit
*  Purpose     : The memory used for state memory is freed
*  Description : Stores NULL in *s
*  Returns     : void
*
**************************************************************************
*/
void Cb_gain_average_exit (Cb_gain_averageState **st);
 
/*
**************************************************************************
*
*  Function    : Cb_gain_average
*  Purpose     : Charaterice synthesis speech and detect background noise
*  Returns     : background noise decision; 0 = bgn, 1 = no bgn
*
**************************************************************************
*/
Word16 Cb_gain_average (
   Cb_gain_averageState *st, /* i/o : State variables for CB gain avergeing   */
   enum Mode mode,           /* i   : AMR mode                                */
   Word16 gain_code,         /* i   : CB gain                              Q1 */
   Word16 lsp[],             /* i   : The LSP for the current frame       Q15 */
   Word16 lspAver[],         /* i   : The average of LSP for 8 frames     Q15 */
   Word16 bfi,               /* i   : bad frame indication flag               */
   Word16 prev_bf,           /* i   : previous bad frame indication flag      */
   Word16 pdfi,              /* i   : potential degraded bad frame ind flag   */
   Word16 prev_pdf,          /* i   : prev pot. degraded bad frame ind flag   */
   Word16 inBackgroundNoise, /* i   : background noise decision               */
   Word16 voicedHangover     /* i   : # of frames after last voiced frame     */
);
 
#endif