/*   ITU-T G.729A Speech Coder    ANSI-C Source Code   Version 1.1    Last modified: September 1996   Copyright (c) 1996,   AT&T, France Telecom, NTT, Universite de Sherbrooke   All rights reserved.*//* Functions Corr_xy2() and Cor_h_x()   */#include "typedef.h"#include "basic_op.h"#include "ld8a.h"/*---------------------------------------------------------------------------* * Function corr_xy2()                                                       * * ~~~~~~~~~~~~~~~~~~~                                                       * * Find the correlations between the target xn[], the filtered adaptive      * * codebook excitation y1[], and the filtered 1st codebook innovation y2[].  * *   g_coeff[2]:exp_g_coeff[2] = <y2,y2>                                     * *   g_coeff[3]:exp_g_coeff[3] = -2<xn,y2>                                   * *   g_coeff[4]:exp_g_coeff[4] = 2<y1,y2>                                    * *---------------------------------------------------------------------------*/void Corr_xy2(      Word16 xn[],           /* (i) Q0  :Target vector.                  */      Word16 y1[],           /* (i) Q0  :Adaptive codebook.              */      Word16 y2[],           /* (i) Q12 :Filtered innovative vector.     */      Word16 g_coeff[],      /* (o) Q[exp]:Correlations between xn,y1,y2 */      Word16 exp_g_coeff[]   /* (o)       :Q-format of g_coeff[]         */){      Word16   i,exp;      Word16   exp_y2y2,exp_xny2,exp_y1y2;      Word16   y2y2,    xny2,    y1y2;      Word32   L_acc;      Word16   scaled_y2[L_SUBFR];       /* Q9 */      /*------------------------------------------------------------------*       * Scale down y2[] from Q12 to Q9 to avoid overflow                 *       *------------------------------------------------------------------*/      for(i=0; i<L_SUBFR; i++) {         scaled_y2[i] = shr(y2[i], 3);        }      /* Compute scalar product <y2[],y2[]> */      L_acc = 1;                       /* Avoid case of all zeros */      for(i=0; i<L_SUBFR; i++)         L_acc = L_mac(L_acc, scaled_y2[i], scaled_y2[i]);    /* L_acc:Q19 */      exp      = norm_l(L_acc);      y2y2     = round( L_shl(L_acc, exp) );      exp_y2y2 = add(exp, 19-16);                          /* Q[19+exp-16] */      g_coeff[2]     = y2y2;      exp_g_coeff[2] = exp_y2y2;      /* Compute scalar product <xn[],y2[]> */      L_acc = 1;                       /* Avoid case of all zeros */      for(i=0; i<L_SUBFR; i++)         L_acc = L_mac(L_acc, xn[i], scaled_y2[i]);           /* L_acc:Q10 */      exp      = norm_l(L_acc);      xny2     = round( L_shl(L_acc, exp) );      exp_xny2 = add(exp, 10-16);                          /* Q[10+exp-16] */      g_coeff[3]     = negate(xny2);      exp_g_coeff[3] = sub(exp_xny2,1);                   /* -2<xn,y2> */      /* Compute scalar product <y1[],y2[]> */      L_acc = 1;                       /* Avoid case of all zeros */      for(i=0; i<L_SUBFR; i++)         L_acc = L_mac(L_acc, y1[i], scaled_y2[i]);           /* L_acc:Q10 */      exp      = norm_l(L_acc);      y1y2     = round( L_shl(L_acc, exp) );      exp_y1y2 = add(exp, 10-16);                          /* Q[10+exp-16] */      g_coeff[4]     = y1y2;      exp_g_coeff[4] = sub(exp_y1y2,1);    ;                /* 2<y1,y2> */      return;}/*--------------------------------------------------------------------------* *  Function  Cor_h_X()                                                     * *  ~~~~~~~~~~~~~~~~~~~                                                     * * Compute correlations of input response h[] with the target vector X[].   * *--------------------------------------------------------------------------*/void Cor_h_X(     Word16 h[],        /* (i) Q12 :Impulse response of filters      */     Word16 X[],        /* (i)     :Target vector                    */     Word16 D[]         /* (o)     :Correlations between h[] and D[] */                        /*          Normalized to 13 bits            */){   Word16 i, j;   Word32 s, max, L_temp;   Word32 y32[L_SUBFR];   /* first keep the result on 32 bits and find absolute maximum */   max = 0;   for (i = 0; i < L_SUBFR; i++)   {     s = 0;     for (j = i; j <  L_SUBFR; j++)       s = L_mac(s, X[j], h[j-i]);     y32[i] = s;     s = L_abs(s);     L_temp =L_sub(s,max);     if(L_temp>0L) {        max = s;     }   }   /* Find the number of right shifts to do on y32[]  */   /* so that maximum is on 13 bits                   */   j = norm_l(max);   if( sub(j,16) > 0) {    j = 16;   }   j = sub(18, j);   for(i=0; i<L_SUBFR; i++) {     D[i] = extract_l( L_shr(y32[i], j) );   }   return;}