code: public static void pred_lt_3(         /* Compute adaptive codebook                       */
  	  float exc[],int excs,          /* in/out: excitation vector, exc[0:l_sub-1] = out */
  	  int t0,               /* input : pitch lag                               */
  	  int frac,             /* input : Fraction of pitch lag (-1, 0, 1)  / 3   */
  	  int l_subfr           /* input : length of subframe.                     */
  	)
  	{
  
  	  int   i, j, k;
  	  float s;
  	  int x0, x1, x2, c1, c2;
  
  
  	  x0 = -t0;//&exc[-t0];
  
  	  frac = -frac;
  	  if (frac < 0) {
  	    frac += LD8KConstants.UP_SAMP;
  	    x0--;
  	  }
  
  	  for (j=0; j<l_subfr; j++)
  	  {
  	    x1 = x0++;
  	    x2 = x0;
  	    c1 = frac;//&inter_3l[frac];
  	    c2 = LD8KConstants.UP_SAMP-frac;//&inter_3l[LD8KConstants.UP_SAMP-frac];
  
  	    s = (float)0.0;
  	    for(i=0, k=0; i< LD8KConstants.L_INTER10; i++, k+=LD8KConstants.UP_SAMP)
  	      s+= exc[excs+x1-i] * TabLD8k.inter_3l[c1+k] + exc[excs+x2+i] * TabLD8k.inter_3l[c2+k];
  
  	    exc[excs+j] = s;
  	  }
  
  	  return;
  	}
docs: /*-------------------------------------------------------------------*
  Function  Pred_lt_3()                                             *
  ~~~~~~~~~~~                                             *
  -------------------------------------------------------------------*
  Compute the result of long term prediction with fractional        *
  interpolation of resolution 1/3.                                  *
  *
  On return exc[0..L_subfr-1] contains the interpolated signal      *
  (adaptive codebook excitation)                                  *
  -------------------------------------------------------------------