acelp_ca.c

具有浮点指令的g.729语音压缩编码

   rri2i2 = rri1i1 + NB_POS;
   rri3i3 = rri2i2 + NB_POS;
   rri4i4 = rri3i3 + NB_POS;
   rri0i1 = rri4i4 + NB_POS;
   rri0i2 = rri0i1 + MSIZE;
   rri0i3 = rri0i2 + MSIZE;
   rri0i4 = rri0i3 + MSIZE;
   rri1i2 = rri0i4 + MSIZE;
   rri1i3 = rri1i2 + MSIZE;
   rri1i4 = rri1i3 + MSIZE;
   rri2i3 = rri1i4 + MSIZE;
   rri2i4 = rri2i3 + MSIZE;

 /*-----------------------------------------------------------------------*
  * Chose the sign of the impulse.                                        *
  *-----------------------------------------------------------------------*/

   for (i=0; i<L_SUBFR; i++)
   {
     if (dn[i] >= (F)0.0)
     {
       sign_dn[i] = (F)1.0;
       sign_dn_inv[i] = (F)-1.0;
     }
     else
     {
       sign_dn[i] = (F)-1.0;
       sign_dn_inv[i] = (F)1.0;
       dn[i] = -dn[i];
     }
   }

 /*-------------------------------------------------------------------*
  * Modification of rrixiy[] to take signs into account.              *
  *-------------------------------------------------------------------*/

  p0 = rri0i1;
  p1 = rri0i2;
  p2 = rri0i3;
  p3 = rri0i4;

  for(i0=0; i0<L_SUBFR; i0+=STEP)
  {
    psign = sign_dn;
    if (psign[i0] < 0.0) psign = sign_dn_inv;

    for(i1=1; i1<L_SUBFR; i1+=STEP)
    {
      *p0 *= psign[i1];    p0++;
      *p1 *= psign[i1+1];  p1++;
      *p2 *= psign[i1+2];  p2++;
      *p3 *= psign[i1+3];  p3++;
    }
  }

  p0 = rri1i2;
  p1 = rri1i3;
  p2 = rri1i4;

  for(i1=1; i1<L_SUBFR; i1+=STEP)
  {
    psign = sign_dn;
    if (psign[i1] < 0.0) psign = sign_dn_inv;

    for(i2=2; i2<L_SUBFR; i2+=STEP)
    {
      *p0 *= psign[i2];   p0++;
      *p1 *= psign[i2+1]; p1++;
      *p2 *= psign[i2+2]; p2++;
    }
  }

  p0 = rri2i3;
  p1 = rri2i4;

  for(i2=2; i2<L_SUBFR; i2+=STEP)
  {
    psign = sign_dn;
    if (psign[i2] < 0.0) psign = sign_dn_inv;

    for(i3=3; i3<L_SUBFR; i3+=STEP)
    {
      *p0 *= psign[i3];   p0++;
      *p1 *= psign[i3+1]; p1++;
    }
  }


 /*-------------------------------------------------------------------*
  * Search the optimum positions of the four pulses which maximize    *
  *     square(correlation) / energy                                  *
  *-------------------------------------------------------------------*/

  psk = (F)-1.0;
  alpk = (F)1.0;

  ptr_rri0i3_i4 = rri0i3;
  ptr_rri1i3_i4 = rri1i3;
  ptr_rri2i3_i4 = rri2i3;
  ptr_rri3i3_i4 = rri3i3;

  /* search 2 times: track 3 and 4 */

  for (track=3, trk=0; track<5; track++, trk++)
  {
   /*------------------------------------------------------------------*
    * depth first search 3, phase A: track 2 and 3/4.                  *
    *------------------------------------------------------------------*/

    sq = (F)-1.0;
    alp = (F)1.0;

    /* i0 loop: 2 positions in track 2 */

    prev_i0  = -1;

    for (i=0; i<2; i++)
    {
      max = (F)-1.0;
      /* search "dn[]" maximum position in track 2 */
      for (j=2; j<L_SUBFR; j+=STEP)
      {
        if( ((dn[j] - max) > (F)0.0) && ((prev_i0-j) != 0) )
        {
          max = dn[j];
          i0 = j;
        }
      }
      prev_i0 = i0;

      j = i0 / 5;        /* j = i0/5 */
      p0 = rri2i2 + j;

      ps1 = dn[i0];
      alp1 = 0.5 * *p0;

      /* i1 loop: 8 positions in track 2 */

      p0 = ptr_rri2i3_i4 + (j<<3);
      p1 = ptr_rri3i3_i4;

      for (i1=track; i1<L_SUBFR; i1+=STEP)
      {
        ps2 = ps1 + dn[i1];
        alp2 = alp1 + *p0++ + *p1++ * (F)0.5;
        sq2 = ps2 * ps2;
        s = alp*sq2 - sq * alp2;
        if (s > (F)0.0)
        {
          sq = sq2;
          ps = ps2;
          alp = alp2;
          ix = i0;
          iy = i1;
        }
      }
    }

    i0 = ix;
    i1 = iy;
    i1_offset = (i1/5) <<3;           /* j = 8*(i1/5) */

   /*------------------------------------------------------------------*
    * depth first search 3, phase B: track 0 and 1.                    *
    *------------------------------------------------------------------*/

    ps0 = ps;
    alp0 = alp;

    sq = (F)-1.0;
    alp = (F)1.0;

    /* build vector for next loop to decrease complexity */

    p0 = rri1i2 + i0/5;
    p1 = ptr_rri1i3_i4 + i1/5;
    p2 = rri1i1;
    p3 = tmp_vect;

    for (i3=1; i3<L_SUBFR; i3+=STEP)
    {
      *p3++ = *p0 + *p1 + *p2 * (F)0.5;
      p0 += NB_POS; p1 += NB_POS; p2++;
    }

    /* i2 loop: 8 positions in track 0 */

    p0 = rri0i2 + i0/5;
    p1 = ptr_rri0i3_i4 + i1/5;
    p2 = rri0i0;
    p3 = rri0i1;

    for (i2=0; i2<L_SUBFR; i2+=STEP)
    {
      ps1 = ps0 + dn[i2];

      alp1 = alp0 + *p0 + *p1 + *p2 * (F)0.5;
      p0 += NB_POS; p1 += NB_POS; p2++;

      /* i3 loop: 8 positions in track 1 */

      p4 = tmp_vect;

      for (i3=1; i3<L_SUBFR; i3+=STEP)
      {
        ps2 = ps1 + dn[i3];

        alp2 = alp1 + *p3++ + *p4++;

        sq2 = ps2 * ps2;
        s = alp*sq2 - sq * alp2;
        if (s > 0.0)
        {
          sq = sq2;
          alp = alp2;
          ix = i2;
          iy = i3;
        }
      }
    }

   /*----------------------------------------------------------------*
    * depth first search 3: compare codevector with the best case.   *
    *----------------------------------------------------------------*/

    s = alpk*sq - psk * alp;
    if (s > (F)0.0)
    {
      psk = sq;
      alpk = alp;
      ip2 = i0;
      ip3 = i1;
      ip0 = ix;
      ip1 = iy;
    }

   /*------------------------------------------------------------------*
    * depth first search 4, phase A: track 3 and 0.                    *
    *------------------------------------------------------------------*/

    sq = (F)-1.0;
    alp = (F)1.0;

    /* i0 loop: 2 positions in track 3/4 */

    prev_i0  = -1;

    for (i=0; i<2; i++)
    {
      max = (F)-1.0;
      /* search "dn[]" maximum position in track 3/4 */
      for (j=track; j<L_SUBFR; j+=STEP)
      {
        if( ((dn[j] - max) > 0) && ((prev_i0 -j) != 0) )
        {
          max = dn[j];
          i0 = j;
        }
      }
      prev_i0 = i0;

      j = i0/5;
      p0 = ptr_rri3i3_i4 + j;

      ps1 = dn[i0];
      alp1 = 0.5 * *p0;

      /* i1 loop: 8 positions in track 0 */

      p0 = ptr_rri0i3_i4 + j;
      p1 = rri0i0;

      for (i1=0; i1<L_SUBFR; i1+=STEP)
      {
        ps2 = ps1 + dn[i1];

        alp2 = alp1 + *p0 + *p1 * (F)0.5;
        p0 += NB_POS;
        p1++;

        sq2 = ps2 * ps2;
        s = alp*sq2 - sq * alp2;
        if (s > (F)0.0)
        {
          sq = sq2;
          ps = ps2;
          alp = alp2;
          ix = i0;
          iy = i1;
        }
      }
    }

    i0 = ix;
    i1 = iy;
    i1_offset = (i1/5) <<3;           /* j = 8*(i1/5) */

   /*------------------------------------------------------------------*
    * depth first search 4, phase B: track 1 and 2.                    *
    *------------------------------------------------------------------*/

    ps0 = ps;
    alp0 = alp;

    sq = (F)-1.0;
    alp = (F)1.0;

    /* build vector for next loop to decrease complexity */

    p0 = ptr_rri2i3_i4 + i0/5;
    p1 = rri0i2 + i1_offset;
    p2 = rri2i2;
    p3 = tmp_vect;

    for (i3=2; i3<L_SUBFR; i3+=STEP)
    {
      *p3++ = *p0 + *p1 + *p2 * (F)0.5;
      p0 += NB_POS; p1++; p2++;
    }

    /* i2 loop: 8 positions in track 1 */

    p0 = ptr_rri1i3_i4 + i0/5;
    p1 = rri0i1 + i1_offset;
    p2 = rri1i1;
    p3 = rri1i2;

    for (i2=1; i2<L_SUBFR; i2+=STEP)
    {
      ps1 = ps0 + dn[i2];

      alp1 = alp0 + *p0 + *p1 + *p2 * (F)0.5;
      p0 += NB_POS; p1++; p2++;

      /* i3 loop: 8 positions in track 2 */

      p4 = tmp_vect;

      for (i3=2; i3<L_SUBFR; i3+=STEP)
      {
        ps2 = ps1 + dn[i3];
        alp2 = alp1 + *p3++ + *p4++;
        sq2 = ps2 * ps2;
        s = alp*sq2 - sq * alp2;
        if (s > (F)0.0)
        {
          sq = sq2;
          alp = alp2;
          ix = i2;
          iy = i3;
        }
      }
    }

   /*----------------------------------------------------------------*
    * depth first search 1: compare codevector with the best case.   *
    *----------------------------------------------------------------*/

    s = alpk*sq - psk*alp;
    if (s > (F)0.0)
    {
      psk = sq;
      alpk = alp;
      ip3 = i0;
      ip0 = i1;
      ip1 = ix;
      ip2 = iy;
    }
  ptr_rri0i3_i4 = rri0i4;
  ptr_rri1i3_i4 = rri1i4;
  ptr_rri2i3_i4 = rri2i4;
  ptr_rri3i3_i4 = rri4i4;

  }


 /* Set the sign of impulses */

 i0 = (int)sign_dn[ip0];
 i1 = (int)sign_dn[ip1];
 i2 = (int)sign_dn[ip2];
 i3 = (int)sign_dn[ip3];

 /* Find the codeword corresponding to the selected positions */


 for(i=0; i<L_SUBFR; i++) {
   cod[i] = (F)0.0;
 }

 cod[ip0] = (F)i0;
 cod[ip1] = (F)i1;
 cod[ip2] = (F)i2;
 cod[ip3] = (F)i3;

 /* find the filtered codeword */

 for (i = 0; i < ip0; i++) y[i] = (F)0.0;

 if(i0 > 0)
   for(i=ip0, j=0; i<L_SUBFR; i++, j++) y[i] = h[j];
 else
   for(i=ip0, j=0; i<L_SUBFR; i++, j++) y[i] = -h[j];

 if(i1 > 0)
   for(i=ip1, j=0; i<L_SUBFR; i++, j++) y[i] = y[i] + h[j];
 else
   for(i=ip1, j=0; i<L_SUBFR; i++, j++) y[i] = y[i] - h[j];

 if(i2 > 0)
   for(i=ip2, j=0; i<L_SUBFR; i++, j++) y[i] = y[i] + h[j];
 else
   for(i=ip2, j=0; i<L_SUBFR; i++, j++) y[i] = y[i] - h[j];

 if(i3 > 0)
   for(i=ip3, j=0; i<L_SUBFR; i++, j++) y[i] = y[i] + h[j];
 else
   for(i=ip3, j=0; i<L_SUBFR; i++, j++) y[i] = y[i] - h[j];

 /* find codebook index;  17-bit address */

 i = 0;
 if(i0 > 0) i += 1;
 if(i1 > 0) i += 2;
 if(i2 > 0) i += 4;
 if(i3 > 0) i += 8;
 *sign = i;

 ip0 = ip0/5;
 ip1 = ip1/5;
 ip2 = ip2/5;
 i   = ip3/5;
 j   = i*5;
 j   = ip3 -j -3;
 ip3 = i*2+j;

 i = ip0 + (ip1<<3)+ (ip2<<6)+ (ip3<<9);
 return i;
}