code: public static void lsp_prev_extract(
  	  float lsp[],                /* (i) Q13 : unquantized LSP parameters  */
  	  float lsp_ele[],            /* (o) Q13 : target vector               */
  	  float fg[][],          /* (i) Q15 : MA prediction coef.         */
  	  float freq_prev[][],   /* (i) Q13 : previous LSP vector         */
  	  float fg_sum_inv[]          /* (i) Q12 : inverse previous LSP vector */
  	)
  	{
  	  int j, k;
  
  	  /*----- compute target vectors for each MA coef.-----*/
  	  for( j = 0 ; j < LD8KConstants.M ; j++ ) {
  	      lsp_ele[j]=lsp[j];
  	      for ( k = 0 ; k < LD8KConstants.MA_NP ; k++ )
  	         lsp_ele[j] -= freq_prev[k][j] * fg[k][j];
  	      lsp_ele[j] *= fg_sum_inv[j];
  	   }
  
  	   return;
  	}
docs: /*
  extract elementary LSP from composed LSP with previous LSP