g729ev_fec_ferenc.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.

  IF(Lnoiseen != 0 && Lsegen != 0)
  {
    /* Normalize segen */
    exp_wsp = norm_l(Lsegen);
    mant_wsp = extract_h(L_shl(Lsegen, exp_wsp));
    exp_wsp = sub(30, exp_wsp);

    /* Normalize noiseen */
    exp_noise = norm_l(Lnoiseen);
    mant_noise = extract_h(L_shl(Lnoiseen, exp_noise));
    exp_noise = sub(30, exp_noise);

    /* ensure mant_wsp < mant_noise */
    mant_wsp = shr(mant_wsp, 1);
    exp_wsp = add(exp_wsp, 1);

    /*snr_val = segen / noiseen; *//* Total SNR    */
    snr_val = div_s(mant_wsp, mant_noise);
    exp_snr = sub(exp_wsp, exp_noise);

#if(WMOPS)
    move16();
    move16();
#endif
    /* Put snr_val in Q9 */
    Ltmp = L_shr(snr_val, sub((15 - 9 - 7), exp_snr));  /* Q16 */
    Log2(Ltmp, &exp_et, &frac_et);
    exp_et = sub(exp_et, 16);
    Ltmp = Mpy_32_16(exp_et, frac_et, G729EV_FEC_LG10); /*Ltmp Q14 */
    snr_val = round(L_shl(Ltmp, 16 - 5)); /*Q11 -> Q8 */
  }
  ELSE
  {
    snr_val = (Word16) 0;
#if(WMOPS)
    move16();
#endif
  }

  /* average voicing on second half-frame and look-ahead  */
  Ltmp = L_mult(voicing[0], 16384);
  mean_voi2 = mac_r(Ltmp, voicing[3], 16384);

  /* Average the spectral tilt in dB        */
  Ltmp = L_mult(ee[0], ee[1]);

  een = extract_h(L_shr(Ltmp, 2));  /*Q14 -> Q11 */
  een = mac_r(G729EV_FEC_C_EE, een, G729EV_FEC_K_EE);
#if(WMOPS)
  test();
  test();
#endif
  if (een < 0 || ee[0] < 0 || ee[1] < 0)
  {
    een = (Word16) 0;
#if(WMOPS)
    move16();
#endif
  }
  if (sub(een, 512) > 0)        /*0.75 Q9 */
  {
    een = (Word16) 512;
#if(WMOPS)
    move16();
#endif
  }
#if(WMOPS)
  move16();
#endif

  /* Compute the zero crossing rate    */
  zc = (Word16) 0;
  FOR(i = 1; i < G729EV_FEC_L_FRAME_FER; i++)
  {
#if(WMOPS)
    test();
#endif
    if ((speech[i] <= 0) && (speech[i - 1] > 0))
    {
      zc = add(zc, 1);
    }
  }

  /* Compute the pitch stability      */
  pc = add(abs_s(sub(pit[2], pit[1])), abs_s(sub(pit[3], pit[2])));
#if(WMOPS)
  move16();
  move16();
  move16();
  move16();
  test();
  test();
  test();
#endif
  /* This section is needed ot improve signal classification in noisy condition */
  tmp_mean = *last_relE;
  *last_relE = relE;
  fmerit_fac = (Word16) 16384;

  IF(sub(abs_s(sub(relE, tmp_mean)), add(abs_s(*relE_var), 6 * 256)) < 0 && (sub(old_clas, G729EV_FEC_UNVOICED) <= 0))  /* absolute variation */
  {
    fmerit_fac = (Word16) 13107;
  }
  ELSE if   (sub(sub(relE, tmp_mean), add(*relE_var, 3 * 256)) > 0 && (sub(old_clas, G729EV_FEC_V_TRANSITION) <= 0))
  {
    fmerit_fac = (Word16) 18022;
  }
  ELSE if   (sub(sub(relE, tmp_mean), (add(*relE_var, -5 * 256))) < 0 && (sub(old_clas, G729EV_FEC_V_TRANSITION) >= 0))
  {
    fmerit_fac = (Word16) 9830;
  }
  *relE_var = mac_r(L_mult(1638, sub(relE, tmp_mean)), 31130, *relE_var);
#if(WMOPS)
  move16();
  move32();
#endif

   /*------------------------------------------------------------------------*
    * transform parameters between 0 & 1    
    * find unique merit function            
    *------------------------------------------------------------------------*/
  /*corn = G729EV_FEC_K_COR * mean_voi2 + G729EV_FEC_C_COR; */
  Ltmp = G729EV_FEC_C_COR;

  corn = round(L_shl(L_mac(Ltmp, mean_voi2, G729EV_FEC_K_COR), -4));  /*Q13->Q9 */

  if (sub(corn, 512) > 0)
  {
    corn = (Word16) 512;
#if(WMOPS)
    move16();
#endif
  }
  if (corn < 0)
  {
    corn = (Word16) 0;
#if(WMOPS)
    move16();
#endif
  }
  Ltmp = L_mult(G729EV_FEC_C_ZC_ENC, 4);  /*Q13*Q2 -> Q16 */
  zcn = round(L_shl(L_mac(Ltmp, zc, G729EV_FEC_K_ZC_ENC), 16 - 7)); /*Q0*Q15 + Q16 */

  if (sub(zcn, 512) > 0)
  {
    zcn = (Word16) 512;
#if(WMOPS)
    move16();
#endif
  }
  if (zcn < 0)
  {
    zcn = (Word16) 0;
#if(WMOPS)
    move16();
#endif
  }
  Ltmp = L_mult(G729EV_FEC_C_RELE, 256);  /*Q15 ->Q24 */
  relEn = round(L_shl(L_mac(Ltmp, relE, G729EV_FEC_K_RELE), 1));  /*relE in Q8 but relEn in Q9 */
  if (sub(relEn, 512) > 0)
  {
    relEn = (Word16) 512;
#if(WMOPS)
    move16();
#endif
  }
  if (sub(relEn, 256) < 0)
  {
    relEn = (Word16) 256;
#if(WMOPS)
    move16();
#endif
  }
  Ltmp = G729EV_FEC_C_PC_ENC;   /*Q16 */
  pcn = round(L_shl(L_mac(Ltmp, pc, G729EV_FEC_K_PC_ENC), 16 - 7)); /*Q16 + Q0*Q15 */
#if(WMOPS)
  move32();
#endif

  if (sub(pcn, 512) > 0)
  {
    pcn = (Word16) 512;
#if(WMOPS)
    move16();
#endif
  }
  if (pcn < 0)
  {
    pcn = (Word16) 0;
#if(WMOPS)
    move16();
#endif
  }

  Ltmp = L_mult(G729EV_FEC_C_SNR, 512);
  snrn = mac_r(Ltmp, snr_val, G729EV_FEC_K_SNR);  /* Q25 +Q9*Q15 */


  if (sub(snrn, 512) > 0)
  {
    snrn = (Word16) 512;
#if(WMOPS)
    move16();
#endif
  }
  if (snrn < 0)
  {
    snrn = (Word16) 0;
#if(WMOPS)
    move16();
#endif
  }
#if(WMOPS)
  move16();
  move16();
  move16();
#endif
  IF(sub(relEn, 256) <= 0)
  {
    var1 = (Word16) 9830;
    var2 = (Word16) 19661;
    var3 = (Word16) 11796;
  }
  ELSE if   (sub(relEn, 384) > 0)
  {
    var1 = (Word16) 11703;
    var2 = (Word16) 23406;
    var3 = (Word16) 14043;
  }
  ELSE
  {
    var1 = (Word16) 9362;
    var2 = (Word16) 18725;
    var3 = (Word16) 11235;
  }

  Ltmp = L_mult(een, var1);
  Ltmp = L_mac(Ltmp, corn, var2);
  Ltmp = L_mac(Ltmp, zcn, var1);
  Ltmp = L_mac(Ltmp, relEn, var1);
  Ltmp = L_mac(Ltmp, pcn, var1);

  fmerit1 = round(L_shl(L_mac(Ltmp, snrn, var2), 16 - 10 - 1)); /*fmerit1 ->Q15 */
  /* Correction when noisy condition */
  fmerit1 = shl(mult(fmerit_fac, fmerit1), 1);
   /*-----------------------------------------------------------------*
    * frame classification                  
    *-----------------------------------------------------------------*/
#if(WMOPS)
  move16();
#endif
  IF(sub(relE, -2560) < 0)
  {
    clas = G729EV_FEC_UNVOICED;
  }
  ELSE
  {
    SWITCH(old_clas)
    {
case G729EV_FEC_VOICED:
case G729EV_FEC_ONSET:
case G729EV_FEC_V_TRANSITION:

      IF(sub(fmerit1, 18350) < 0)
      {
        clas = G729EV_FEC_UNVOICED;
      }
      ELSE if   (sub(fmerit1, 22282) < 0)
      {
        clas = G729EV_FEC_V_TRANSITION;
      }
      ELSE
      {
        clas = G729EV_FEC_VOICED;
      }
      BREAK;

case G729EV_FEC_UNVOICED:
case G729EV_FEC_UV_TRANSITION:


      IF(sub(fmerit1, 20972) > 0)
      {
        clas = G729EV_FEC_ONSET;
      }
      ELSE if   (sub(fmerit1, 19005) > 0)
      {
        clas = G729EV_FEC_UV_TRANSITION;
      }
      ELSE
      {
        clas = G729EV_FEC_UNVOICED;
      }
      BREAK;

default:
      clas = G729EV_FEC_UNVOICED;
      BREAK;
    }
  }

  IF(sub(clas, G729EV_FEC_V_TRANSITION) > 0)
  {
    *lp_speech = mac_r(L_mult(32440, *lp_speech), 328, Etot);
#if(WMOPS)
    move16();
#endif
  }


  return clas;
}


/*---------------------------------------------------------------------*
 *  Signal classification encoding
 *---------------------------------------------------------------------*/

static Word16 G729EV_FEC_clas_enc(  /* o: quantization index                */
                                   const Word16 clas  /* i:   signal clas for current frame   */
    )
{
  Word16    index;

#if(WMOPS)
  move16();
  test();
#endif
  IF(sub(clas, G729EV_FEC_UNVOICED) == 0)
  {
    index = (Word16) 0;
  }
  ELSE if   ((sub(clas, G729EV_FEC_V_TRANSITION) == 0) || (sub(clas, G729EV_FEC_UV_TRANSITION) == 0))
  {
    index = (Word16) 1;
  }
  ELSE if   (sub(clas, G729EV_FEC_VOICED) == 0)
  {
    index = (Word16) 2;
  }
  ELSE                          /* G729EV_FEC_ONSET        */
  {
    index = (Word16) 3;
  }
  return index;
}