g729ev_fec_decbfi.c

最新的ITU-T的宽带语音编解码标准G.729.1,是对原先的G.729的最好的调整.码流输出速率可以进行自适应调整.满足未来通信要求.希望对大家有所帮助.

        move16();
#endif
      }
#if(WMOPS)
      move16();
#endif
      pos = Tc;
    }
    /* last pitch cycle of the previous frame is repeatedly copied up to an extra subframe */
    FOR(i = pos; i < G729EV_MAIN_L_FRAME2 + G729EV_G729_L_SUBFR; i++)
    {
      *pt_exc++ = *pt1_exc++;
      move16();
#if(WMOPS)
      move16();
#endif
    }
    IF(new_pit > 0)
    {

      pit_subfr = (Word16) 0;
#if(WMOPS)
      move16();
#endif

      IF(sub(puls_pos, -1000) == 0) /* Information of pulse position is not present */
      {
        /* Only possible when more than 1 frame erasure or with bitrate < 14 kbps */

        i = 1;
        tmp2 = pitch_buf[0];
        tmp16 = (Word16) 0;
#if(WMOPS)
        move16();
        move16();
        move16();
#endif

             /*------------------------------------------------------------
              * Total delay of all pitch cycles in the concealed frame is computed 
              * for both Tc used in concealment and future (or estimated)
              *------------------------------------------------------------*/
        WHILE(sub(tmp2, (G729EV_MAIN_L_FRAME2 - G729EV_G729_PIT_MIN) * G729EV_FEC_QPIT) < 0)
        {
          tmp16 = mult(shr(tmp2, G729EV_FEC_SQPIT), 819);
          tmp2 = add(pitch_buf[tmp16], tmp2);
          i = add(i, 1);
        }
             /*------------------------------------------------------------
              * Find estimated pitch lags per subframe 
              * estimation of the difference between the last concealed 
              * maximum glottal pulse in the frame and the estimated pulse  
              *------------------------------------------------------------*/
        total_pit_lag = sub(i_mult(i, Tc), shr(add(tmp2, G729EV_FEC_QPIT2), G729EV_FEC_SQPIT));

        /* have to play safe when we extrapolate a pulse position */
        if (sub(total_pit_lag, 35) > 0)
        {
          total_pit_lag = (Word16) 0;
#if(WMOPS)
          move16();
#endif
        }
        if (sub(total_pit_lag, -35) < 0)
        {
          total_pit_lag = (Word16) 0;
#if(WMOPS)
          move16();
#endif
        }

      }
      ELSE
      {
#if(WMOPS)
        move16();
#endif
             /*------------------------------------------------------------
              * Decode phase information transmitted in the bitstream
              * (The position of the absolute maximum glottal pulse from 
              * the end of the frame and its sign)
              *------------------------------------------------------------*/
        P0 = puls_pos;
        if (P0 < 0)
        {
#if(WMOPS)
          move16();
#endif
          sign = (Word16) 1;
          P0 = negate(P0);
        }
        IF(sub(Tc, 128) >= 0)
        {
          P0 = shl(P0, 2);
          P0 = add(P0, 2);
        }
        ELSE if   (sub(Tc, 64) >= 0)
        {
          P0 = shl(P0, 1);
          P0 = add(P0, 1);
        }
        if (sub(P0, 160) > 0)
        {
          P0 = (Word16) 160;    /* Should never be the case, however... */
#if(WMOPS)
          move16();
#endif
        }
      }
#if(WMOPS)
      move16();
#endif
      pit_search = Tc;

      if (sign)                 /* Take sign in account to find right pulse */
      {
        pit_search = negate(pit_search);
      }

      /* Find the position of the first the maximum(minimum) lp_filtered pulse */
      /* <----- Mem --->|<--------------------- L_FRAME ------------>|<----- L_SUBFR --->| */
      /*                |<-------pit_search---->                     |                   | */
      Tlist[0] = G729EV_FEC_findpulse(exc, pit_search, 0);

      /*nb_pusles =  (G729EV_MAIN_L_FRAME2 / Tc) + 1; */
      tmp2 = shl(Tc, 7);
      tmp2 = div_s(1280, tmp2);
      nb_pusles = add(shr(tmp2, 11), 1);

      /* Extrapolate the position of all the other pulses */
      /* puls_list contains realtive pulse position  P = Pulse TL = Puls_list */
      /* |<--------------------- L_FRAME --------------------->|<----- L_SUBFR --->| */
      /* |    P                 p                 p            |    p              | */
      /* |   TL[0]             TL[1]             TL[2]         |   TL[x]           | */
#if(WMOPS)
      move16();
#endif
      FOR(i = 1; i < nb_pusles; i++)
      {
        Tlist[i] = add(Tlist[i - 1], Tc);
#if(WMOPS)
        move16();
#endif
      }
      IF(sub(puls_pos, -1000) == 0) /* Information of pulse position is not present */
      {
        IF(sub(G729EV_MAIN_L_FRAME2, Tlist[nb_pusles - 1]) >= 0)  /* We try to find the right pulse pos */
        {
          P0 = add(sub(G729EV_MAIN_L_FRAME2, Tlist[nb_pusles - 1]), total_pit_lag);
        }
        ELSE
        {
          P0 = add(sub(G729EV_MAIN_L_FRAME2, Tlist[nb_pusles - 2]), total_pit_lag);
        }
      }
#if(WMOPS)
      move16();
      move16();
#endif
      /* Choose on wich pulse to start the correction in function of pulse position sent by the encoder */
      pulse_chosen = (Word16) 0;
      Terr = (Word16) 200;
      Plast = sub(G729EV_MAIN_L_FRAME2, P0);
      FOR(i = 0; i < nb_pusles; i++)
      {
        tmp16 = abs_s(sub(Plast, Tlist[i]));
        if (sub(tmp16, Terr) < 0)
        {
          Terr = tmp16;
          pulse_chosen = i;
#if(WMOPS)
          move16();
          move16();
#endif
        }
      }
      diff_pit = abs_s(sub(new_pit, Tc));
      tmp16 = shl(Tc, 7);
      tmp16 = shr(add(div_s(1280, tmp16), 1024), 11);
      dist_Plast = sub(G729EV_MAIN_L_FRAME2, Tlist[pulse_chosen]);

#if(WMOPS)
      test();
      test();
#endif
      IF(((Terr <= i_mult(diff_pit, tmp16))) && (Terr != 0) /*   If Terr = 0, no resynchronization required */
         && (sub(Terr, G729EV_G729_L_SUBFR) < 0)) /* prevent catastrophy search */
      {
        /* performe excitation resynchronization here */
        G729EV_FEC_synchro_exc(exc, P0, dist_Plast, Tc);
      }

    }
    IF((sub(last_good, G729EV_FEC_UV_TRANSITION) == 0))
    {
      gain = (Word16) 24576;
      *lp_gainp = shr(alpha, 2);  /*lp_gainp in Q14 */
#if(WMOPS)
      move16();
      move16();
#endif
    }
    ELSE
    {
      gain = (Word16) 32767;    /* start-of-the-frame gain */
      *lp_gainp = shr(alpha, 1);  /* end-of-the-frame gain, save attenuation factor for the next frame */
#if(WMOPS)
      move16();
      move16();
#endif
    }
    /* step = (1.0f/L_FRAME) * (gain - *lp_gainp); */
    step = mult_r(sub(shr(gain, 1), *lp_gainp), 410);

    FOR(i = 0; i < G729EV_MAIN_L_FRAME2; i++)
    {
      /* Linearly attenuate the gain through the frame */
      /*exc[i] *= gain; */
      exc[i] = mult_r(exc[i], gain);  /* in Q_exc */
      /*gain -= step; */
      gain = sub(gain, step);
#if(WMOPS)
      move16();

#endif
    }
    /* Update old_exc without random part   */
    G729EV_G729_Copy(&exc[G729EV_MAIN_L_FRAME2 - G729EV_FEC_L_EXC_MEM], exc_mem, G729EV_FEC_L_EXC_MEM);
  }                             /* end of "if last_good >= G729EV_FEC_V_TRANSITION"  */

   /*-------------------------------------------------*
    * Construct the random part of excitation         *
    *-------------------------------------------------*/
  FOR(i = 0; i < G729EV_MAIN_L_FRAME2 + G729EV_FEC_L_FIR_FER - 1; i++)
  {
    /*exc2[i] = (float)G729EV_G729_random_g729c( seed ); */
    exc2[i] = shr(G729EV_G729_Random(seed), 3); /*Q-3 */
#if(WMOPS)
    move16();
#endif
  }
#if(WMOPS)
  test();
  test();
#endif
  if ((sub(last_good, G729EV_FEC_V_TRANSITION) > 0) ||
      ((sub(last_good, G729EV_FEC_UV_TRANSITION) > 0) && sub(bfi_cnt, 1) > 0))
  {
    *lp_gainc = shr(*lp_gainc, 1);
#if(WMOPS)
    move16();
#endif
  }
#if(WMOPS)
  move16();
  move16();
#endif
  gain = *lp_gainc;             /*Q3 *//* start-of-the-frame gain */
  *lp_gainc = mult_r(alpha, *lp_gainc);

  if ((sub(last_good, G729EV_FEC_UV_TRANSITION) == 0))
  {
    *lp_gainc = (Word16) 0;
#if(WMOPS)
    move16();
#endif
  }

  /* To avoid saturation split the L_FRAME dot product into 4 L_SUBFR dot products
     and scale down before adding */

  /*pt_exc = exc2 + G729EV_FEC_L_FIR_FER/2; */
  /*gain_inov = 1.0f / (float)sqrt(G729EV_FEC_dproduct( pt_exc, pt_exc, G729EV_MAIN_L_FRAME2 ) / G729EV_MAIN_L_FRAME2 + 0.01f); */
#if(WMOPS)
  move32();
#endif
  pt_exc = exc2 + G729EV_FEC_L_FIR_FER / 2;
  L_tmp = (Word32) 0;
  FOR(i = 0; i < 4; i++)
  {
    L_tmp2 = (Word32) 0;
    FOR(j = 0; j < G729EV_G729_L_SUBFR; j++)
    {
      L_tmp2 = L_mac(L_tmp2, pt_exc[j], pt_exc[j]); /* Q-5 */
    }
#if(WMOPS)
    move32();
#endif
    pt_exc = pt_exc + G729EV_G729_L_SUBFR;
    L_tmp = L_add(L_tmp, L_shr(L_tmp2, 2)); /* Q-7          */
  }
  L_tmp = L_mls(L_tmp, 26214);  /* multiply by 0.8 and remove 7 from exponent to achive a divsion by 160 */
  exp_gain = norm_l(L_tmp);
  L_tmp = L_shl(L_tmp, exp_gain); /* Normalize                  */
  /* Q0, 7 ->divide by 128      */
  exp_gain = sub(31, exp_gain); /* For Denormalization in Q31 */
  Isqrt_n(&L_tmp, &exp_gain);   /* in Q31                     */
  gain_inov = round(L_tmp);     /* In Q15 - exp_gain */
#if(WMOPS)
  move32();
  move16();
#endif
  if (sub(last_good, G729EV_FEC_UNVOICED) == 0) /* Attenuate somewhat on unvoiced   */
  {
    gain_inov = mult_r(gain_inov, 13107);
  }

  pt_exc = exc2;                /* non-causal ringing of the FIR filter         */
#if(WMOPS)
  move16();
#endif
  step = sub(gain, *lp_gainc);  /* divide by L_FRAME done later */

  L_step = L_mls(L_mult(gain_inov, step), 205);
  L_tmp2 = L_mult(gain_inov, gain); /* Q15 * Q3 -> Q3         */
  tmp2 = round(L_tmp2);
  exp_gain = add(exp_gain, 16); /* 3+Q_exc+15 -> Q_exc+18 */

  FOR(i = 0; i < G729EV_FEC_L_FIR_FER / 2; i++)
  {
    /* *pt_exc++ *= (gain_inov * gain); */
    L_tmp = L_mult(tmp2, *pt_exc);  /* Q_exc+18 * Q-3 -> Q_exc+16 */
    *pt_exc++ = round(L_shl(L_tmp, exp_gain));
#if(WMOPS)
    move16();
#endif
  }

  FOR(i = 0; i < G729EV_MAIN_L_FRAME2; i++)  /* Actual filtered random part of excitation */
  {
    /* *pt_exc++ *= (gain_inov * gain); */
    L_tmp = L_mult(tmp2, *pt_exc);
    *pt_exc++ = round(L_shl(L_tmp, exp_gain));
    /* gain -= step; */
    L_tmp2 = L_sub(L_tmp2, L_step);
    tmp2 = round(L_tmp2);
#if(WMOPS)
    move16();
#endif
  }

  FOR(i = 0; i < G729EV_FEC_L_FIR_FER / 2; i++)  /* causal ringing of the FIR filter   */
  {
    /* *pt_exc++ *= (gain_inov * gain); */
    L_tmp = L_mult(tmp2, *pt_exc);
    *pt_exc++ = round(L_shl(L_tmp, exp_gain));
#if(WMOPS)
    move16();
#endif
  }

   /*-------------------------------------------------*
    * Construct the total excitation         
    *-------------------------------------------------*/
  IF(sub(last_good, G729EV_FEC_UV_TRANSITION) >= 0)
  {
       /*-------------------------------------------------*
        * innovation excitation is filtered through 
        * a linear phase FIR high-pass filter
        *-------------------------------------------------*/
    pt_exc = exc2;
    FOR(i = 0; i < G729EV_MAIN_L_FRAME2; i++)
    {
      L_tmp = 0;
      move32();
      L_tmp = L_mac(L_tmp, hp_filt[0], pt_exc[0]);
      L_tmp = L_mac(L_tmp, hp_filt[1], pt_exc[1]);