/********************************************************************************      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             : dtx_dec.h*      Purpose          : Decode comfort noice when in DTX*******************************************************************************/#ifndef dtx_dec_h#define dtx_dec_h "$Id $"  /*******************************************************************************                         INCLUDE FILES******************************************************************************/#include "typedef.h"#include "dtx_enc.h"#include "d_plsf.h"#include "gc_pred.h"#include "c_g_aver.h"#include "frame.h"/*******************************************************************************                         LOCAL VARIABLES AND TABLES******************************************************************************/enum DTXStateType {SPEECH = 0, DTX, DTX_MUTE};#define DTX_MAX_EMPTY_THRESH 50/*******************************************************************************                         DEFINITION OF DATA TYPES******************************************************************************/typedef struct {   Word16 since_last_sid;   Word16 true_sid_period_inv;   Word16 log_en;   Word16 old_log_en;   Word32 L_pn_seed_rx;    Word16 lsp[M];   Word16 lsp_old[M];       Word16 lsf_hist[M*DTX_HIST_SIZE];   Word16 lsf_hist_ptr;   Word16 lsf_hist_mean[M*DTX_HIST_SIZE];    Word16 log_pg_mean;   Word16 log_en_hist[DTX_HIST_SIZE];   Word16 log_en_hist_ptr;   Word16 log_en_adjust;   Word16 dtxHangoverCount;   Word16 decAnaElapsedCount;   Word16 sid_frame;          Word16 valid_data;             Word16 dtxHangoverAdded;    enum DTXStateType dtxGlobalState;     /* contains previous state */                                         /* updated in main decoder */    Word16 data_updated;      /* marker to know if CNI data is ever renewed */ } dtx_decState;/*******************************************************************************                         DECLARATION OF PROTOTYPES******************************************************************************//****************************************************************************  Function    : dtx_dec_init*  Purpose     : Allocates memory and initializes state variables*  Description : Stores pointer to filter status struct in *st. This*                pointer has to be passed to dtx_dec in each call.*  Returns     : 0 on success****************************************************************************/ int dtx_dec_init (dtx_decState **st); /*****************************************************************************  Function    : dtx_dec_reset*  Purpose     : Resets state memory*  Returns     : 0 on success****************************************************************************/int dtx_dec_reset (dtx_decState *st); /*****************************************************************************  Function    : dtx_dec_exit*  Purpose     : The memory used for state memory is freed*  Description : Stores NULL in *st****************************************************************************/void dtx_dec_exit (dtx_decState **st); /*****************************************************************************  Function    : dtx_dec*  Purpose     :*  Description :*                ***************************************************************************/int dtx_dec(   dtx_decState *st,                /* i/o : State struct                    */   Word16 mem_syn[],                /* i/o : AMR decoder state               */   D_plsfState* lsfState,           /* i/o : decoder lsf states              */   gc_predState* predState,         /* i/o : prediction states               */   Cb_gain_averageState* averState, /* i/o : CB gain average states          */   enum DTXStateType new_state,     /* i   : new DTX state                   */       enum Mode mode,                  /* i   : AMR mode                        */   Word16 parm[],                   /* i   : Vector of synthesis parameters  */   Word16 synth[],                  /* o   : synthesised speech              */   Word16 A_t[]                     /* o   : decoded LP filter in 4 subframes*/   );void dtx_dec_activity_update(dtx_decState *st,                             Word16 lsf[],                             Word16 frame[]);/*****************************************************************************  Function    : rx_dtx_handler *  Purpose     : reads the frame type and checks history  *  Description : to decide what kind of DTX/CNI action to perform***************************************************************************/enum DTXStateType rx_dtx_handler(dtx_decState *st,           /* i/o : State struct */                                 enum RXFrameType frame_type /* i   : Frame type   */                                 );#endif