dtx_dec.c

arm音频编解码库

      }      
      test();
      if (sub(ma_pred_init, -14436) < 0)
      {
         ma_pred_init = -14436;                                     move16();
      }
      
      predState->past_qua_en[0] = ma_pred_init;                     move16();
      predState->past_qua_en[1] = ma_pred_init;                     move16();
      predState->past_qua_en[2] = ma_pred_init;                     move16();
      predState->past_qua_en[3] = ma_pred_init;                     move16();

      /* past_qua_en for other modes than MR122 */      
      ma_pred_init = mult(5443, ma_pred_init); 
      /* scale down by factor 20*log10(2) in Q15 */
      predState->past_qua_en_MR122[0] = ma_pred_init;               move16();
      predState->past_qua_en_MR122[1] = ma_pred_init;               move16();
      predState->past_qua_en_MR122[2] = ma_pred_init;               move16();
      predState->past_qua_en_MR122[3] = ma_pred_init;               move16();
   } /* endif sid_frame */
   
   /* CN generation */
   /* recompute level adjustment factor Q11             *
    * st->log_en_adjust = 0.9*st->log_en_adjust +       *
    *                     0.1*dtx_log_en_adjust[mode]); */
   move16();
   st->log_en_adjust = add(mult(st->log_en_adjust, 29491),
                           shr(mult(shl(dtx_log_en_adjust[mode],5),3277),5));

   /* Interpolate SID info */
   int_fac = shl(add(1,st->since_last_sid), 10); /* Q10 */                 move16();
   int_fac = mult(int_fac, st->true_sid_period_inv); /* Q10 * Q15 -> Q10 */
   
   /* Maximize to 1.0 in Q10 */
   test();
   if (sub(int_fac, 1024) > 0)
   {
      int_fac = 1024;                                               move16();
   }
   int_fac = shl(int_fac, 4); /* Q10 -> Q14 */
   
   L_log_en_int = L_mult(int_fac, st->log_en); /* Q14 * Q11->Q26 */ move32();
   for(i = 0; i < M; i++)
   {
      lsp_int[i] = mult(int_fac, st->lsp[i]);/* Q14 * Q15 -> Q14 */ move16();
   }
   
   int_fac = sub(16384, int_fac); /* 1-k in Q14 */                  move16();

   /* (Q14 * Q11 -> Q26) + Q26 -> Q26 */
   L_log_en_int = L_mac(L_log_en_int, int_fac, st->old_log_en);
   for(i = 0; i < M; i++)
   {
      /* Q14 + (Q14 * Q15 -> Q14) -> Q14 */
      lsp_int[i] = add(lsp_int[i], mult(int_fac, st->lsp_old[i]));  move16();
      lsp_int[i] = shl(lsp_int[i], 1); /* Q14 -> Q15 */             move16();
   }
   
   /* compute the amount of lsf variability */
   lsf_variab_factor = sub(st->log_pg_mean,2457); /* -0.6 in Q12 */ move16();
   /* *0.3 Q12*Q15 -> Q12 */
   lsf_variab_factor = sub(4096, mult(lsf_variab_factor, 9830)); 

   /* limit to values between 0..1 in Q12 */ 
   test();
   if (sub(lsf_variab_factor, 4096) > 0)
   {
      lsf_variab_factor = 4096;                                     move16();
   }
   test();
   if (lsf_variab_factor < 0)
   {
      lsf_variab_factor = 0;                                        move16(); 
   }
   lsf_variab_factor = shl(lsf_variab_factor, 3); /* -> Q15 */      move16();

   /* get index of vector to do variability with */
   lsf_variab_index = pseudonoise(&st->L_pn_seed_rx, 3);            move16();

   /* convert to lsf */
   Lsp_lsf(lsp_int, lsf_int, M);

   /* apply lsf variability */
   Copy(lsf_int, lsf_int_variab, M);
   for(i = 0; i < M; i++)
   {
      move16();
      lsf_int_variab[i] = add(lsf_int_variab[i], 
                              mult(lsf_variab_factor,
                                   st->lsf_hist_mean[i+lsf_variab_index*M]));
   }

   /* make sure that LSP's are ordered */
   Reorder_lsf(lsf_int, LSF_GAP, M);
   Reorder_lsf(lsf_int_variab, LSF_GAP, M);

   /* copy lsf to speech decoders lsf state */
   Copy(lsf_int, lsfState->past_lsf_q, M);

   /* convert to lsp */
   Lsf_lsp(lsf_int, lsp_int, M);
   Lsf_lsp(lsf_int_variab, lsp_int_variab, M);

   /* Compute acoeffs Q12 acoeff is used for level    * 
    * normalization and postfilter, acoeff_variab is  *
    * used for synthesis filter                       *
    * by doing this we make sure that the level       *
    * in high frequenncies does not jump up and down  */

   Lsp_Az(lsp_int, acoeff);
   Lsp_Az(lsp_int_variab, acoeff_variab);
   
   /* For use in postfilter */
   Copy(acoeff, &A_t[0],           M + 1);
   Copy(acoeff, &A_t[M + 1],       M + 1);
   Copy(acoeff, &A_t[2 * (M + 1)], M + 1);
   Copy(acoeff, &A_t[3 * (M + 1)], M + 1);
   
   /* Compute reflection coefficients Q15 */
   A_Refl(&acoeff[1], refl);
   
   /* Compute prediction error in Q15 */
   pred_err = MAX_16; /* 0.99997 in Q15 */                          move16();
   for (i = 0; i < M; i++)
   { 
      pred_err = mult(pred_err, sub(MAX_16, mult(refl[i], refl[i])));
   }

   /* compute logarithm of prediction gain */   
   Log2(L_deposit_l(pred_err), &log_pg_e, &log_pg_m);
   
   /* convert exponent and mantissa to Word16 Q12 */
   log_pg = shl(sub(log_pg_e,15), 12);  /* Q12 */                   move16();
   log_pg = shr(sub(0,add(log_pg, shr(log_pg_m, 15-12))), 1);       move16();
   st->log_pg_mean = add(mult(29491,st->log_pg_mean),
                         mult(3277, log_pg));                       move16();

   /* Compute interpolated log energy */
   L_log_en_int = L_shr(L_log_en_int, 10); /* Q26 -> Q16 */         move32();

   /* Add 4 in Q16 */
   L_log_en_int = L_add(L_log_en_int, 4 * 65536L);                  move32();

   /* subtract prediction gain */
   L_log_en_int = L_sub(L_log_en_int, L_shl(L_deposit_l(log_pg), 4));move32();

   /* adjust level to speech coder mode */
   L_log_en_int = L_add(L_log_en_int, 
                        L_shl(L_deposit_l(st->log_en_adjust), 5));  move32();
       
   log_en_int_e = extract_h(L_log_en_int);                    move16();
   move16();
   log_en_int_m = extract_l(L_shr(L_sub(L_log_en_int, 
                                        L_deposit_h(log_en_int_e)), 1));
   level = extract_l(Pow2(log_en_int_e, log_en_int_m)); /* Q4 */ move16();
   
   for (i = 0; i < 4; i++)
   {             
      /* Compute innovation vector */
      build_CN_code(&st->L_pn_seed_rx, ex);
      for (j = 0; j < L_SUBFR; j++)
      {
         ex[j] = mult(level, ex[j]);                                move16();
      }
      /* Synthesize */
      Syn_filt(acoeff_variab, ex, &synth[i * L_SUBFR], L_SUBFR, 
               mem_syn, 1);
      
   } /* next i */
   
   /* reset codebook averaging variables */ 
   averState->hangVar = 20;                                         move16();
   averState->hangCount = 0;                                        move16();
    
   test();
   if (sub(new_state, DTX_MUTE) == 0)
   {
      /* mute comfort noise as it has been quite a long time since  
       * last SID update  was performed                            */
      
      tmp_int_length = st->since_last_sid;                          move16();
      test();
      if (sub(tmp_int_length, 32) > 0)
      {
         tmp_int_length = 32;                                       move16();
      }
      
      /* safety guard against division by zero */
      test();
      if(tmp_int_length <= 0) {
         tmp_int_length = 8;                                       move16();
      }      
      
      move16();
      st->true_sid_period_inv = div_s(1 << 10, shl(tmp_int_length, 10)); 

      st->since_last_sid = 0;                                       move16();
      Copy(st->lsp, st->lsp_old, M);
      st->old_log_en = st->log_en;                                  move16();
      /* subtract 1/8 in Q11 i.e -6/8 dB */
      st->log_en = sub(st->log_en, 256);                            move16();  
   }

   /* reset interpolation length timer 
    * if data has been updated.        */
   test(); test(); test(); test();
   if ((st->sid_frame != 0) && 
       ((st->valid_data != 0) || 
        ((st->valid_data == 0) &&  (st->dtxHangoverAdded) != 0))) 
   {
      st->since_last_sid =  0;                                      move16();
      st->data_updated = 1;                                         move16();
   }
         
   return 0;
}

void dtx_dec_activity_update(dtx_decState *st,
                             Word16 lsf[],
                             Word16 frame[])
{
   Word16 i;

   Word32 L_frame_en;
   Word16 log_en_e, log_en_m, log_en;

   /* update lsp history */
   st->lsf_hist_ptr = add(st->lsf_hist_ptr,M);                     move16();
   test();
   if (sub(st->lsf_hist_ptr, 80) == 0)
   {
      st->lsf_hist_ptr = 0;                                        move16();
   }
   Copy(lsf, &st->lsf_hist[st->lsf_hist_ptr], M); 

   /* compute log energy based on frame energy */
   L_frame_en = 0;     /* Q0 */                                    move32();
   for (i=0; i < L_FRAME; i++)
   {
      L_frame_en = L_mac(L_frame_en, frame[i], frame[i]); 
   }
   Log2(L_frame_en, &log_en_e, &log_en_m);
   
   /* convert exponent and mantissa to Word16 Q10 */
   log_en = shl(log_en_e, 10);  /* Q10 */                          
   log_en = add(log_en, shr(log_en_m, 15-10));                      
   
   /* divide with L_FRAME i.e subtract with log2(L_FRAME) = 7.32193 */
   log_en = sub(log_en, 7497+1024);                                
   
   /* insert into log energy buffer, no division by two as  *
    * log_en in decoder is Q11                              */
   st->log_en_hist_ptr = add(st->log_en_hist_ptr, 1);
   test();
   if (sub(st->log_en_hist_ptr, DTX_HIST_SIZE) == 0)
   {
      st->log_en_hist_ptr = 0;                                     move16();
   }
   st->log_en_hist[st->log_en_hist_ptr] = log_en; /* Q11 */        move16();
}

/*   
     Table of new SPD synthesis states 
     
                           |     previous SPD_synthesis_state
     Incoming              |  
     frame_type            | SPEECH       | DTX           | DTX_MUTE   
     ---------------------------------------------------------------
     RX_SPEECH_GOOD ,      |              |               |
     RX_SPEECH_PR_DEGRADED | SPEECH       | SPEECH        | SPEECH 
     ----------------------------------------------------------------       
     RX_SPEECH_BAD,        | SPEECH       | DTX           | DTX_MUTE
     ----------------------------------------------------------------
     RX_SID_FIRST,         | DTX          | DTX/(DTX_MUTE)| DTX_MUTE  
     ----------------------------------------------------------------
     RX_SID_UPDATE,        | DTX          | DTX           | DTX
     ----------------------------------------------------------------
     RX_SID_BAD,           | DTX          | DTX/(DTX_MUTE)| DTX_MUTE
     ----------------------------------------------------------------
     RX_NO_DATA            | SPEECH       | DTX/(DTX_MUTE)| DTX_MUTE
                           |(class2 garb.)|               |
     ----------------------------------------------------------------
     RX_ONSET              | SPEECH       | DTX/(DTX_MUTE)| DTX_MUTE
                           |(class2 garb.)|               |
     ----------------------------------------------------------------
*/

enum DTXStateType rx_dtx_handler(
                      dtx_decState *st,           /* i/o : State struct     */
                      enum RXFrameType frame_type /* i   : Frame type       */ 
                      )
{
   enum DTXStateType newState;
   enum DTXStateType encState;

   /* DTX if SID frame or previously in DTX{_MUTE} and (NO_RX OR BAD_SPEECH) */
   test(); test(); test();
   test(); test(); test();
   test(); test();   
   if ((sub(frame_type, RX_SID_FIRST) == 0)   ||
       (sub(frame_type, RX_SID_UPDATE) == 0)  ||
       (sub(frame_type, RX_SID_BAD) == 0)     ||
       (((sub(st->dtxGlobalState, DTX) == 0) ||
         (sub(st->dtxGlobalState, DTX_MUTE) == 0)) && 
        ((sub(frame_type, RX_NO_DATA) == 0) ||
         (sub(frame_type, RX_SPEECH_BAD) == 0) || 
         (sub(frame_type, RX_ONSET) == 0))))
   {
      newState = DTX;                                              move16();

      /* stay in mute for these input types */
      test(); test(); test(); test(); test();
      if ((sub(st->dtxGlobalState, DTX_MUTE) == 0) &&
          ((sub(frame_type, RX_SID_BAD) == 0) ||
           (sub(frame_type, RX_SID_FIRST) ==  0) ||
           (sub(frame_type, RX_ONSET) ==  0) ||
           (sub(frame_type, RX_NO_DATA) == 0)))
      {
         newState = DTX_MUTE;                                      move16();
      }

      /* evaluate if noise parameters are too old                     */
      /* since_last_sid is reset when CN parameters have been updated */
      st->since_last_sid = add(st->since_last_sid, 1);             move16();

      /* no update of sid parameters in DTX for a long while */
      /* Due to the delayed update of  st->since_last_sid counter
         SID_UPDATE frames need to be handled separately to avoid
         entering DTX_MUTE for late SID_UPDATE frames
         */
      test(); test(); logic16();
      if((sub(frame_type, RX_SID_UPDATE) != 0) &&
         (sub(st->since_last_sid, DTX_MAX_EMPTY_THRESH) > 0))
      {
         newState = DTX_MUTE;                                      move16();
      }
   }
   else 
   {
      newState = SPEECH;                                           move16();
      st->since_last_sid = 0;                                      move16();
   }
   
   /* 
      reset the decAnaElapsed Counter when receiving CNI data the first  
      time, to robustify counter missmatch after handover
      this might delay the bwd CNI analysis in the new decoder slightly.
   */    
   test(); test();
   if ((st->data_updated == 0) &&
       (sub(frame_type, RX_SID_UPDATE) == 0))
   {
      st->decAnaElapsedCount = 0;                                  move16();
   }

   /* update the SPE-SPD DTX hangover synchronization */
   /* to know when SPE has added dtx hangover         */
   st->decAnaElapsedCount = add(st->decAnaElapsedCount, 1);        move16();
   st->dtxHangoverAdded = 0;                                       move16();
   
   test(); test(); test(); test(); test();
   if ((sub(frame_type, RX_SID_FIRST) == 0)  ||
       (sub(frame_type, RX_SID_UPDATE) == 0) ||
       (sub(frame_type, RX_SID_BAD) == 0)    ||
       (sub(frame_type, RX_ONSET) == 0)      ||
       (sub(frame_type, RX_NO_DATA) == 0))
   {
      encState = DTX;                                              move16();
      
      /*         
         In frame errors simulations RX_NO_DATA may occasionally mean that
         a speech packet was probably sent by the encoder,
         the assumed _encoder_ state should be SPEECH in such cases.
      */
      
      test(); logic16(); 
      if((sub(frame_type, RX_NO_DATA) == 0) &&
         (sub(newState, SPEECH) == 0)) 
      {
         encState = SPEECH;                                       move16();
      }
      
      
      /* Note on RX_ONSET operation differing from RX_NO_DATA operation:
         If a  RX_ONSET is received in the decoder (by "accident")
         it is still most likely that the encoder  state
         for the "ONSET frame" was DTX.
      */      
   }
   else 
   {
      encState = SPEECH;                                           move16();
   }
 
   test();
   if (sub(encState, SPEECH) == 0)
   {
      st->dtxHangoverCount = DTX_HANG_CONST;                       move16();
   }
   else
   {
      test();
      if (sub(st->decAnaElapsedCount, DTX_ELAPSED_FRAMES_THRESH) > 0)
      {
         st->dtxHangoverAdded = 1;                                 move16();
         st->decAnaElapsedCount = 0;                               move16();
         st->dtxHangoverCount = 0;                                 move16();
      }
      else if (test(), st->dtxHangoverCount == 0)
      {
         st->decAnaElapsedCount = 0;                               move16();
      }
      else
      {
         st->dtxHangoverCount = sub(st->dtxHangoverCount, 1);      move16();
      }
   }
   
   if (sub(newState, SPEECH) != 0)
   {
      /* DTX or DTX_MUTE
       * CN data is not in a first SID, first SIDs are marked as SID_BAD 
       *  but will do backwards analysis if a hangover period has been added
       *  according to the state machine above 
       */
      
      st->sid_frame = 0;                                           move16();
      st->valid_data = 0;                                          move16();
            
      test(); 
      if (sub(frame_type, RX_SID_FIRST) == 0)
      {
         st->sid_frame = 1;                                        move16();
      }
      else if (test(), sub(frame_type, RX_SID_UPDATE) == 0)
      {
         st->sid_frame = 1;                                        move16();
         st->valid_data = 1;                                       move16();
      }
      else if (test(), sub(frame_type, RX_SID_BAD) == 0)
      {
         st->sid_frame = 1;                                        move16();
         st->dtxHangoverAdded = 0; /* use old data */              move16();
      } 
   }

   return newState; 
   /* newState is used by both SPEECH AND DTX synthesis routines */ 
}