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.

  IF((sub(prev_bfi, G729EV_FEC_GOOD_FRAME) != 0))
  {
       /*------------------------------------------------------------*
        * Speech synthesis at 8 kHz sampling rate                  *
        *------------------------------------------------------------*/
    G729EV_G729_Copy(mem_tmp, mem_syn, G729EV_G729_M);
#if(WMOPS)
    move16();
#endif
    p_Az = Aq;
    FOR(i_subfr = 0; i_subfr < G729EV_MAIN_L_FRAME2; i_subfr += G729EV_G729_L_SUBFR)
    {
      G729EV_G729_Syn_filt2(p_Az, &exc_tmp[i_subfr], &synth[i_subfr], G729EV_G729_L_SUBFR, mem_syn, 1);
#if(WMOPS)
      move16();
#endif
      p_Az += (G729EV_G729_M + 1);
    }
  }
  return;
}

/******************************************************************************/
/* G729EV_FEC_enr_1_Az : To find impulse response energy                      */
/******************************************************************************/
static Word16 G729EV_FEC_enr_1_Az(  /* o:   impulse response energy */
                                   Word16 Aq[], /* i:   LP filter coefs         */
                                   Word16 len   /* i:   impulse response length */
    )
{
  Word16    i, enr_LP, h1[2 * G729EV_G729_L_SUBFR], mem[G729EV_G729_M];
  Word32    L_tmp;

  /* Find the impulse response */
  G729EV_G729_Set_zero(h1, len);
  G729EV_G729_Set_zero(mem, G729EV_G729_M);
  h1[0] = 1024;                 /* h1_in Q10, h1_out Q10 */
  G729EV_G729_Syn_filt(Aq, h1, h1, len, mem, 0);

#if(WMOPS)
  move16();
  move32();
#endif
  /* Find the impulse response energy */
  L_tmp = (Word32) 0;
  FOR(i = 0; i < len; i++)
  {
    L_tmp = L_mac0(L_tmp, h1[i], h1[i]);
  }
  enr_LP = round(L_tmp);        /* Q21 to Q5 */

  return enr_LP;
}

/******************************************************************************/
/* G729EV_FEC_synchro_exc : To resynchronize concealed                        */
/* - Find number of minimum energy region                                     */
/* - Find location of minimum energy region                                   */
/* - Find number of sample to add/remove by minimum energy region             */
/* - Synchronisation (sample deletion/addition)                               */
/******************************************************************************/
static void G729EV_FEC_synchro_exc(Word16 * exc,           /* i/o : exc vector to modify */
                                   Word16 desire_puls_pos, /* Pulse position send by the encoder */
                                   Word16 true_puls_pos,   /* Present pulse location */
                                   Word16 Old_pitch        /* Pitch use to create temporary adaptive codebook */
    )
{

  Word16    exc_tmp[G729EV_MAIN_L_FRAME2 + G729EV_G729_L_SUBFR], *pt_exc, *pt_exc1, tmp16, fact;
  Word32    L_tmp, L_tmp1;
  Word16    remaining_len;
  Word16    i, j, k, point_to_remove, point_to_add, nb_min, points_by_pos[10], total_point;
  Word16   *pt_pos, pos, start_search, tmp_len;
  Word16    min_pos[10];

  point_to_add = -1;
#if(WMOPS)
  move16();
#endif
  FOR(i = 0; i < 10; i++)
  {
    min_pos[i] = (Word16) - 10000;
    points_by_pos[i] = (Word16) 0;
#if(WMOPS)
    move16();
    move16();
#endif
  }

  /* Find number of point to remove and number of minimum */
  point_to_remove = sub(true_puls_pos, desire_puls_pos);  /* if it is negative it means remove point else it means add point */

  /* Find number of minimum energy region */
  tmp16 = shl(Old_pitch, 7);
  tmp_len = sub(G729EV_MAIN_L_FRAME2, true_puls_pos);
  tmp16 = div_s(shl(tmp_len, 3), tmp16);
  nb_min = shr(tmp16, 11);

  /* if Old pitch < 80, must have at least 2 min */
#if (WMOPS)
  test();
#endif
  if (sub(Old_pitch, 80) <= 0 && sub(nb_min, 2) < 0)
  {
    nb_min = (Word16) 2;
#if(WMOPS)
    move16();
#endif
  }
  /* Must have at least 1 min */
  if (nb_min == 0)
  {
    nb_min = (Word16) 1;
#if(WMOPS)
    move16();
#endif
  }
#if(WMOPS)
  move16();
  move16();
#endif

  pos = tmp_len;
  pt_exc = exc + pos;

  /* Find starting point for minimum energy search */
  start_search = shr_r(i_mult(-3, Old_pitch), 2);
  IF(add(start_search, pos) < 0)
  {
    start_search = negate(pos);
    if (sub(abs_s(start_search), shr(Old_pitch, 3)) < 0)
    {
      /* it's not safe to remove/add point inside 1/8 of the pulse position */
      return;
    }
  }

  /* Find min energy in the first pitch section */
#if(WMOPS)
  move32();
#endif
  /* --------------------------------------------------------------------
   * The minimum energy regions are determined by the computing the energy 
   * using a sliding 5-sample window. The minimum energy position is set 
   * at the middle of the window at which the energy is at minimum
   * --------------------------------------------------------------------*/
  L_tmp = MAX_32;
  L_tmp1 = L_mult(pt_exc[start_search], pt_exc[start_search]);
  L_tmp1 = L_mac(L_tmp1, pt_exc[start_search + 1], pt_exc[start_search + 1]);
  L_tmp1 = L_mac(L_tmp1, pt_exc[start_search + 2], pt_exc[start_search + 2]);
  L_tmp1 = L_mac(L_tmp1, pt_exc[start_search + 3], pt_exc[start_search + 3]);
  L_tmp1 = L_mac(L_tmp1, pt_exc[start_search + 4], pt_exc[start_search + 4]);

  IF(L_sub(L_tmp1, L_tmp) < 0)
  {
    L_tmp = L_tmp1;
    min_pos[0] = add(add(pos, start_search), 2);
#if(WMOPS)
    move32();
    move16();
#endif
  }
  FOR(i = start_search; i < -5; i++)
  {
    L_tmp1 = L_msu(L_tmp1, pt_exc[i], pt_exc[i]);
    L_tmp1 = L_mac(L_tmp1, pt_exc[i + 5], pt_exc[i + 5]);
    IF(L_sub(L_tmp1, L_tmp) < 0)
    {
      L_tmp = L_tmp1;
      min_pos[0] = add(add(pos, i), 2);
#if(WMOPS)
      move32();
      move16();
#endif
    }
  }

  FOR(j = 1; j < nb_min; j++)
  {
#if(WMOPS)
    move16();
#endif
    min_pos[j] = sub(min_pos[j - 1], Old_pitch);
    /* If the first minimum is in the past, forget this minimum */
    if (min_pos[j] < 0)
    {
      min_pos[j] = -10000;
      nb_min = sub(nb_min, 1);
#if(WMOPS)
      move16();
#endif
    }
  }
  /* --------------------------------------------------------------------
   * Determine the number of samples to be added or removed at each pitch 
   * cycle whereby less samples are added/removed at the beginning and 
   * more towards the end of the frame
   * --------------------------------------------------------------------*/
#if(WMOPS)
  test();
#endif
  IF(sub(nb_min, 1) == 0 || sub(abs_s(point_to_remove), 1) == 0)
  {
    nb_min = 1;
    points_by_pos[0] = abs_s(point_to_remove);
    total_point = points_by_pos[0];
#if(WMOPS)
    move16();
    move16();
    move16();
#endif
  }
  ELSE
  {
    /* First position */
    /*fact = (float)fabs(point_to_remove) / sqi[nb_min-2]; (nb_min*nb_min); */
    fact = mult_r(shl(abs_s(point_to_remove), 7), inv_sqi[nb_min - 2]); /*Q7 */
    points_by_pos[0] = shr(add(fact, 64), 7); /*Q7 */
    total_point = points_by_pos[0];
#if(WMOPS)
    move16();
    move16();
#endif
    FOR(i = 2; i <= nb_min; i++)
    {
      /*points_by_pos[i-1] = (Word16)(fact*(sqi[i-2]) - total_point+0.5) ; */
#if(WMOPS)
      move16();
#endif
      points_by_pos[i - 1] = sub(shr(add(i_mult(fact, sqi[i - 2]), 64), 7), total_point);
      total_point = add(total_point, points_by_pos[i - 1]);
      /* ensure a constant increase */
      IF(sub(points_by_pos[i - 1], points_by_pos[i - 2]) < 0)
      {
#if(WMOPS)
        move16();
        move16();
        move16();
#endif
        tmp16 = points_by_pos[i - 2];
        points_by_pos[i - 2] = points_by_pos[i - 1];
        points_by_pos[i - 1] = tmp16;
      }
    }
  }
  /* --------------------------------------------------------------------
   * Sample deletion or insertion is performed in minimum energy regions. 
   * At the end of this section the last maximum pulse in the concealed 
   * excitation is forced to align to the actual maximum pulse position 
   * at the end of the frame which is transmitted in the future frame.
   * --------------------------------------------------------------------*/
  if (point_to_remove > 0)
  {
    point_to_add = point_to_remove;
#if(WMOPS)
    move16();
#endif
  }

  pt_exc = exc_tmp;
  pt_exc1 = exc;
  pt_pos = min_pos + sub(nb_min, 1);

#if(WMOPS)
  move16();
  move16();
#endif

  i = 0;
  k = 0;
  pt_pos = min_pos + sub(nb_min, 1);
  IF(point_to_add > 0)          /* Samples insertion */
  {
    remaining_len = G729EV_MAIN_L_FRAME2;
#if(WMOPS)
    move16();
#endif
    FOR(i = 0; i < nb_min; i++)
    {
      if (i == 0)
      {
        /*Compute len to copy */
        tmp_len = *pt_pos;
#if(WMOPS)
        move16();
#endif
      }
      IF(i > 0)
      {
        /*Compute len to copy */
        tmp_len = sub(sub(*pt_pos, *(pt_pos + 1)), points_by_pos[i - 1]);
      }
      /*Copy section */
      G729EV_G729_Copy(pt_exc1, pt_exc, tmp_len);
      remaining_len = sub(remaining_len, tmp_len);
#if(WMOPS)
      move16();
      move16();
#endif
      pt_exc1 += tmp_len;
      pt_exc += tmp_len;

      /*Find point to add and Add points */
      tmp16 = mult_r(*pt_exc1, -1638);
      FOR(j = 0; j < points_by_pos[i]; j++)
      {
        *pt_exc++ = tmp16;      /* repeat last point  */
        tmp16 = negate(tmp16);
#if(WMOPS)
        move16();
#endif
      }

      remaining_len = sub(remaining_len, points_by_pos[i]);
      pt_pos--;
    }
    /* Copy remaining data */
    G729EV_G729_Copy(pt_exc1, pt_exc, remaining_len);
    /* Update excitation vector */
    G729EV_G729_Copy(exc_tmp, exc, G729EV_MAIN_L_FRAME2);
  }
  ELSE                          /* Samples deletion */
  {
    remaining_len = G729EV_MAIN_L_FRAME2;
#if(WMOPS)
    move16();
#endif
    FOR(i = 0; i < nb_min; i++)
    {
      if (i == 0)
      {
        /*Compute len to copy */
        tmp_len = *pt_pos;
#if(WMOPS)
        move16();
#endif
      }
      IF(i > 0)
      {
        /*Compute len to copy */
        tmp_len = sub(sub(*pt_pos, *(pt_pos + 1)), points_by_pos[i - 1]);
      }
      G729EV_G729_Copy(pt_exc1, pt_exc, tmp_len);
      remaining_len = sub(remaining_len, tmp_len);
      pt_exc1 += tmp_len;
      pt_exc += tmp_len;
#if(WMOPS)
      move16();
      move16();
#endif
      /* Remove points */
      FOR(j = 0; j < points_by_pos[i]; j++)
      {
        pt_exc1++;
      }
      pt_pos--;
    }
    /* Copy remaining data */
    G729EV_G729_Copy(pt_exc1, pt_exc, remaining_len);
    /* Update excitation vector */
    G729EV_G729_Copy(exc_tmp, exc, G729EV_MAIN_L_FRAME2);
  }
  return;
}