dtx_dec.c

arm音频编解码库

/*
*****************************************************************************
*
*      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.c
*      Purpose          : Decode comfort noise when in DTX
*
*****************************************************************************
*/
/*
*****************************************************************************
*                         MODULE INCLUDE FILE AND VERSION ID
*****************************************************************************
*/
#include "dtx_dec.h"
const char dtx_dec_id[] = "@(#)$Id $" dtx_dec_h;
 
/*
*****************************************************************************
*                         INCLUDE FILES
*****************************************************************************
*/
#include <stdlib.h>
#include <stdio.h>
#include "typedef.h"
#include "basic_op.h"
#include "oper_32b.h"
#include "copy.h"
#include "set_zero.h"
#include "mode.h"
#include "log2.h"
#include "lsp_az.h"
#include "pow2.h"
#include "a_refl.h"
#include "b_cn_cod.h"
#include "syn_filt.h"
#include "lsp_lsf.h"
#include "reorder.h"
#include "count.h"
#include "q_plsf_5.tab"
#include "lsp.tab"

/*
*****************************************************************************
*                         LOCAL VARIABLES AND TABLES
*****************************************************************************
*/
#define PN_INITIAL_SEED 0x70816958L   /* Pseudo noise generator seed value  */

/***************************************************
 * Scaling factors for the lsp variability operation *
 ***************************************************/
static const Word16 lsf_hist_mean_scale[M] = {
   20000,
   20000,
   20000,
   20000,
   20000,
   18000,
   16384,
    8192,
       0,
       0
};

/*************************************************
 * level adjustment for different modes Q11      *
 *************************************************/
static const Word16 dtx_log_en_adjust[9] =
{
  -1023, /* MR475 */
   -878, /* MR515 */
   -732, /* MR59  */
   -586, /* MR67  */
   -440, /* MR74  */
   -294, /* MR795 */
   -148, /* MR102 */
      0, /* MR122 */
      0, /* MRDTX */
};

/*
*****************************************************************************
*                         PUBLIC PROGRAM CODE
*****************************************************************************
*/
/*
**************************************************************************
*
*  Function    : dtx_dec_init
*
**************************************************************************
*/ 
int dtx_dec_init (dtx_decState **st)
{
   dtx_decState* s;
   
   if (st == (dtx_decState **) NULL){
      fprintf(stderr, "dtx_dec_init: invalid parameter\n");
      return -1; 
   }
   
   *st = NULL;
   
   /* allocate memory */
   if ((s= (dtx_decState *) malloc(sizeof(dtx_decState))) == NULL){
      fprintf(stderr, "dtx_dec_init: can not malloc state structure\n");
      return -1;
   }
   
   dtx_dec_reset(s);
   *st = s;
   
   return 0;
}
 
/*
**************************************************************************
*
*  Function    : dtx_dec_reset
*
**************************************************************************
*/
int dtx_dec_reset (dtx_decState *st)
{
   int i;

   if (st == (dtx_decState *) NULL){
      fprintf(stderr, "dtx_dec_reset: invalid parameter\n");
      return -1;
   }
   
   st->since_last_sid = 0;
   st->true_sid_period_inv = (1 << 13); 
 
   st->log_en = 3500;  
   st->old_log_en = 3500;
   /* low level noise for better performance in  DTX handover cases*/
   
   st->L_pn_seed_rx = PN_INITIAL_SEED;

   /* Initialize state->lsp [] and state->lsp_old [] */
   Copy(lsp_init_data, &st->lsp[0], M);
   Copy(lsp_init_data, &st->lsp_old[0], M);

   st->lsf_hist_ptr = 0;
   st->log_pg_mean = 0;
   st->log_en_hist_ptr = 0;

   /* initialize decoder lsf history */
   Copy(mean_lsf, &st->lsf_hist[0], M);

   for (i = 1; i < DTX_HIST_SIZE; i++)
   {
      Copy(&st->lsf_hist[0], &st->lsf_hist[M*i], M);
   }
   Set_zero(st->lsf_hist_mean, M*DTX_HIST_SIZE);

   /* initialize decoder log frame energy */ 
   for (i = 0; i < DTX_HIST_SIZE; i++)
   {
      st->log_en_hist[i] = st->log_en;
   }

   st->log_en_adjust = 0;

   st->dtxHangoverCount = DTX_HANG_CONST;
   st->decAnaElapsedCount = 32767;   

   st->sid_frame = 0;       
   st->valid_data = 0;             
   st->dtxHangoverAdded = 0; 
  
   st->dtxGlobalState = DTX;    
   st->data_updated = 0; 
   return 0;
}
 
/*
**************************************************************************
*
*  Function    : dtx_dec_exit
*
**************************************************************************
*/
void dtx_dec_exit (dtx_decState **st)
{
   if (st == NULL || *st == NULL)
      return;
   
   /* deallocate memory */
   free(*st);
   *st = NULL;
   
   return;
}

/*
**************************************************************************
*
*  Function    : dtx_dec
*                
**************************************************************************
*/
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*/
   )
{
   Word16 log_en_index;
   Word16 i, j;
   Word16 int_fac;
   Word32 L_log_en_int;
   Word16 lsp_int[M];
   Word16 log_en_int_e;
   Word16 log_en_int_m;
   Word16 level;
   Word16 acoeff[M + 1];
   Word16 refl[M];
   Word16 pred_err;
   Word16 ex[L_SUBFR];
   Word16 ma_pred_init;
   Word16 log_pg_e, log_pg_m;
   Word16 log_pg;
   Flag negative;
   Word16 lsf_mean;
   Word32 L_lsf_mean;
   Word16 lsf_variab_index;
   Word16 lsf_variab_factor;
   Word16 lsf_int[M];
   Word16 lsf_int_variab[M];
   Word16 lsp_int_variab[M];
   Word16 acoeff_variab[M + 1];

   Word16 lsf[M];
   Word32 L_lsf[M];
   Word16 ptr;
   Word16 tmp_int_length;


   /*  This function is called if synthesis state is not SPEECH 
    *  the globally passed  inputs to this function are 
    * st->sid_frame 
    * st->valid_data 
    * st->dtxHangoverAdded
    * new_state  (SPEECH, DTX, DTX_MUTE)
    */

   test(); test();
   if ((st->dtxHangoverAdded != 0) && 
       (st->sid_frame != 0))
   {
      /* sid_first after dtx hangover period */
      /* or sid_upd after dtxhangover        */

      /* set log_en_adjust to correct value */
      st->log_en_adjust = dtx_log_en_adjust[mode];
          
      ptr = add(st->lsf_hist_ptr, M);                               move16(); 
      test();
      if (sub(ptr, 80) == 0)
      {
         ptr = 0;                                                   move16();
      }
      Copy( &st->lsf_hist[st->lsf_hist_ptr],&st->lsf_hist[ptr],M); 
      
      ptr = add(st->log_en_hist_ptr,1);                             move16();
      test();
      if (sub(ptr, DTX_HIST_SIZE) == 0)
      {
         ptr = 0;                                                   move16();
      }
      move16();
      st->log_en_hist[ptr] = st->log_en_hist[st->log_en_hist_ptr]; /* Q11 */
      
      /* compute mean log energy and lsp *
       * from decoded signal (SID_FIRST) */         
      st->log_en = 0;                                               move16();
      for (i = 0; i < M; i++)
      {
         L_lsf[i] = 0;                                              move16();
      }
      
      /* average energy and lsp */
      for (i = 0; i < DTX_HIST_SIZE; i++)
      {
         st->log_en = add(st->log_en,
                          shr(st->log_en_hist[i],3));
         for (j = 0; j < M; j++)
         {
            L_lsf[j] = L_add(L_lsf[j],
                             L_deposit_l(st->lsf_hist[i * M + j]));
         }
      }
       
      for (j = 0; j < M; j++)
      {
         lsf[j] = extract_l(L_shr(L_lsf[j],3)); /* divide by 8 */  move16();
      }
      
      Lsf_lsp(lsf, st->lsp, M); 

      /* make log_en speech coder mode independent */
      /* added again later before synthesis        */
      st->log_en = sub(st->log_en, st->log_en_adjust);

      /* compute lsf variability vector */
      Copy(st->lsf_hist, st->lsf_hist_mean, 80);

      for (i = 0; i < M; i++)
      {
         L_lsf_mean = 0;                                           move32();
         /* compute mean lsf */
         for (j = 0; j < 8; j++)
         {
            L_lsf_mean = L_add(L_lsf_mean, 
                               L_deposit_l(st->lsf_hist_mean[i+j*M]));
         }
         
         lsf_mean = extract_l(L_shr(L_lsf_mean, 3));               move16();
         /* subtract mean and limit to within reasonable limits  *
          * moreover the upper lsf's are attenuated              */
         for (j = 0; j < 8; j++)
         {
            /* subtract mean */ 
            st->lsf_hist_mean[i+j*M] = 
               sub(st->lsf_hist_mean[i+j*M], lsf_mean);

            /* attenuate deviation from mean, especially for upper lsf's */
            st->lsf_hist_mean[i+j*M] = 
               mult(st->lsf_hist_mean[i+j*M], lsf_hist_mean_scale[i]);

            /* limit the deviation */
            test();
            if (st->lsf_hist_mean[i+j*M] < 0)
            {
               negative = 1;                                        move16();
            }
            else
            {
               negative = 0;                                        move16();
            }
            st->lsf_hist_mean[i+j*M] = abs_s(st->lsf_hist_mean[i+j*M]);

            /* apply soft limit */
            test();
            if (sub(st->lsf_hist_mean[i+j*M], 655) > 0)
            {
               st->lsf_hist_mean[i+j*M] = 
                  add(655, shr(sub(st->lsf_hist_mean[i+j*M], 655), 2));
            }
            
            /* apply hard limit */
            test();
            if (sub(st->lsf_hist_mean[i+j*M], 1310) > 0)
            {
               st->lsf_hist_mean[i+j*M] = 1310;                     move16();
            }
            test();
            if (negative != 0) 
            {
               st->lsf_hist_mean[i+j*M] = -st->lsf_hist_mean[i+j*M];move16();
            }
            
         }
      }
   }
   
   test();
   if (st->sid_frame != 0 )
   {
      /* Set old SID parameters, always shift */
      /* even if there is no new valid_data   */
      Copy(st->lsp, st->lsp_old, M);
      st->old_log_en = st->log_en;                                  move16();

      test();
      if (st->valid_data != 0 )  /* new data available (no CRC) */
      {
         /* Compute interpolation factor, since the division only works *
          * for values of since_last_sid < 32 we have to limit the      *
          * interpolation to 32 frames                                  */
         tmp_int_length = st->since_last_sid;                       move16();
         st->since_last_sid = 0;                                    move16();

         test();
         if (sub(tmp_int_length, 32) > 0)
         {
            tmp_int_length = 32;                                    move16();
         }
         test();
         if (sub(tmp_int_length, 2) >= 0)
         {
            move16();
            st->true_sid_period_inv = div_s(1 << 10, shl(tmp_int_length, 10)); 
         }
         else
         {
            st->true_sid_period_inv = 1 << 14; /* 0.5 it Q15 */     move16();
         }
         
         Init_D_plsf_3(lsfState, parm[0]);  /* temporay initialization */ 
         D_plsf_3(lsfState, MRDTX, 0, &parm[1], st->lsp);
         Set_zero(lsfState->past_r_q, M);   /* reset for next speech frame */ 

         log_en_index = parm[4];                                    move16();
         /* Q11 and divide by 4 */
         st->log_en = shl(log_en_index, (11 - 2));                  move16();
         
         /* Subtract 2.5 in Q11 */
         st->log_en = sub(st->log_en, (2560 * 2));
         
         /* Index 0 is reserved for silence */
         test();
         if (log_en_index == 0)
         {
            st->log_en = MIN_16;                                    move16();
         }
         
         /* no interpolation at startup after coder reset        */
         /* or when SID_UPD has been received right after SPEECH */
         test(); test();
         if ((st->data_updated == 0) ||
             (sub(st->dtxGlobalState, SPEECH) == 0)
             ) 
         {
            Copy(st->lsp, st->lsp_old, M);
            st->old_log_en = st->log_en;                            move16();
         }         
      } /* endif valid_data */

      /* initialize gain predictor memory of other modes */       
      ma_pred_init = sub(shr(st->log_en,1), 9000);                  move16();
      test();
      if (ma_pred_init > 0)
      {                   
         ma_pred_init = 0;                                          move16();