qua_gain.c

C源程序---G.729a语音代码G.729a语音代码

   exp_min[0] = add( exp_coeff[0], 13 );
   exp_min[1] = add( exp_coeff[1], 14 );
   exp_min[2] = add( exp_coeff[2], sub( shl( exp_gcode0, 1 ), 21 ) );
   exp_min[3] = add( exp_coeff[3], sub( exp_gcode0, 3 ) );
   exp_min[4] = add( exp_coeff[4], sub( exp_gcode0, 4 ) );

   e_min = exp_min[0];
   for(i=1; i<5; i++){
      if( sub(exp_min[i], e_min) < 0 ){
         e_min = exp_min[i];
      }
   }

   /* align coeff[] and save in special 32 bit double precision */

   for(i=0; i<5; i++){
     j = sub( exp_min[i], e_min );
     L_tmp = L_deposit_h( g_coeff[i] );
     L_tmp = L_shr( L_tmp, j );          /* L_tmp:Q[exp_g_coeff[i]+16-j] */
     L_Extract( L_tmp, &coeff[i], &coeff_lsf[i] );          /* DPF */
   }

   /* Codebook search */

   L_dist_min = MAX_32;

   /* initialization used only to suppress Microsoft Visual C++  warnings */
   index1 = cand1;
   index2 = cand2;

if(tameflag == 1){
   for(i=0; i<NCAN1; i++){
      for(j=0; j<NCAN2; j++){
         g_pitch = add( gbk1[cand1+i][0], gbk2[cand2+j][0] );     /* Q14 */
         if(g_pitch < GP0999) {
         L_acc = L_deposit_l( gbk1[cand1+i][1] );
         L_accb = L_deposit_l( gbk2[cand2+j][1] );                /* Q13 */
         L_tmp = L_add( L_acc,L_accb );
         tmp = extract_l( L_shr( L_tmp,1 ) );                     /* Q12 */

         g_code   = mult( gcode0, tmp );         /*  Q[exp_gcode0+12-15] */
         g2_pitch = mult(g_pitch, g_pitch);                       /* Q13 */
         g2_code  = mult(g_code,  g_code);       /* Q[2*exp_gcode0-6-15] */
         g_pit_cod= mult(g_code,  g_pitch);      /* Q[exp_gcode0-3+14-15] */

         L_tmp = Mpy_32_16(coeff[0], coeff_lsf[0], g2_pitch);
         L_tmp = L_add(L_tmp, Mpy_32_16(coeff[1], coeff_lsf[1], g_pitch) );
         L_tmp = L_add(L_tmp, Mpy_32_16(coeff[2], coeff_lsf[2], g2_code) );
         L_tmp = L_add(L_tmp, Mpy_32_16(coeff[3], coeff_lsf[3], g_code) );
         L_tmp = L_add(L_tmp, Mpy_32_16(coeff[4], coeff_lsf[4], g_pit_cod) );

         L_temp = L_sub(L_tmp, L_dist_min);

         if( L_temp < 0L ){
            L_dist_min = L_tmp;
            index1 = add(cand1,i);
            index2 = add(cand2,j);
         }
        }
      }
   }

}
else{
   for(i=0; i<NCAN1; i++){
      for(j=0; j<NCAN2; j++){
         g_pitch = add( gbk1[cand1+i][0], gbk2[cand2+j][0] );     /* Q14 */
         L_acc = L_deposit_l( gbk1[cand1+i][1] );
         L_accb = L_deposit_l( gbk2[cand2+j][1] );                /* Q13 */
         L_tmp = L_add( L_acc,L_accb );
         tmp = extract_l( L_shr( L_tmp,1 ) );                     /* Q12 */

         g_code   = mult( gcode0, tmp );         /*  Q[exp_gcode0+12-15] */
         g2_pitch = mult(g_pitch, g_pitch);                       /* Q13 */
         g2_code  = mult(g_code,  g_code);       /* Q[2*exp_gcode0-6-15] */
         g_pit_cod= mult(g_code,  g_pitch);      /* Q[exp_gcode0-3+14-15] */

         L_tmp = Mpy_32_16(coeff[0], coeff_lsf[0], g2_pitch);
         L_tmp = L_add(L_tmp, Mpy_32_16(coeff[1], coeff_lsf[1], g_pitch) );
         L_tmp = L_add(L_tmp, Mpy_32_16(coeff[2], coeff_lsf[2], g2_code) );
         L_tmp = L_add(L_tmp, Mpy_32_16(coeff[3], coeff_lsf[3], g_code) );
         L_tmp = L_add(L_tmp, Mpy_32_16(coeff[4], coeff_lsf[4], g_pit_cod) );

         L_temp = L_sub(L_tmp, L_dist_min);

         if( L_temp < 0L ){
            L_dist_min = L_tmp;
            index1 = add(cand1,i);
            index2 = add(cand2,j);
         }

      }
   }
}
   /* Read the quantized gain */

  /*-----------------------------------------------------------------*
   * *gain_pit = gbk1[indice1][0] + gbk2[indice2][0];                *
   *-----------------------------------------------------------------*/
   *gain_pit = add( gbk1[index1][0], gbk2[index2][0] );      /* Q14 */

  /*-----------------------------------------------------------------*
   * *gain_code = (gbk1[indice1][1]+gbk2[indice2][1]) * gcode0;      *
   *-----------------------------------------------------------------*/
   L_acc = L_deposit_l( gbk1[index1][1] );
   L_accb = L_deposit_l( gbk2[index2][1] );
   L_gbk12 = L_add( L_acc, L_accb );                          /* Q13 */
   tmp = extract_l( L_shr( L_gbk12,1 ) );                     /* Q12 */
   L_acc = L_mult(tmp, gcode0);                /* Q[exp_gcode0+12+1] */

   L_acc = L_shl(L_acc, add( negate(exp_gcode0),(-12-1+1+16) ));
   *gain_cod = extract_h( L_acc );                             /* Q1 */

  /*----------------------------------------------*
   * update table of past quantized energies      *
   *----------------------------------------------*/
   Gain_update( past_qua_en, L_gbk12 );

   return( add( map1[index1]*(Word16)NCODE2, map2[index2] ) );

}
/*---------------------------------------------------------------------------*
 * Function Gbk_presel                                                       *
 * ~~~~~~~~~~~~~~~~~~~                                                       *
 *   - presearch for gain codebook -                                         *
 *---------------------------------------------------------------------------*/
static void Gbk_presel(
   Word16 best_gain[],     /* (i) [0] Q9 : unquantized pitch gain     */
                           /* (i) [1] Q2 : unquantized code gain      */
   Word16 *cand1,          /* (o)    : index of best 1st stage vector */
   Word16 *cand2,          /* (o)    : index of best 2nd stage vector */
   Word16 gcode0           /* (i) Q4 : presearch for gain codebook    */
)
{
   Word16    acc_h;
   Word16    sft_x,sft_y;
   Word32    L_acc,L_preg,L_cfbg,L_tmp,L_tmp_x,L_tmp_y;
   Word32 L_temp;

 /*--------------------------------------------------------------------------*
   x = (best_gain[1]-(coef[0][0]*best_gain[0]+coef[1][1])*gcode0) * inv_coef;
  *--------------------------------------------------------------------------*/
   L_cfbg = L_mult( coef[0][0], best_gain[0] );        /* L_cfbg:Q20 -> !!y */
   L_acc = L_shr( L_coef[1][1], 15 );                  /* L_acc:Q20     */
   L_acc = L_add( L_cfbg , L_acc );
   acc_h = extract_h( L_acc );                         /* acc_h:Q4      */
   L_preg = L_mult( acc_h, gcode0 );                   /* L_preg:Q9     */
   L_acc = L_shl( L_deposit_l( best_gain[1] ), 7 );    /* L_acc:Q9      */
   L_acc = L_sub( L_acc, L_preg );
   acc_h = extract_h( L_shl( L_acc,2 ) );              /* L_acc_h:Q[-5] */
   L_tmp_x = L_mult( acc_h, INV_COEF );                /* L_tmp_x:Q15   */

 /*--------------------------------------------------------------------------*
   y = (coef[1][0]*(-coef[0][1]+best_gain[0]*coef[0][0])*gcode0
                                      -coef[0][0]*best_gain[1]) * inv_coef;
  *--------------------------------------------------------------------------*/
   L_acc = L_shr( L_coef[0][1], 10 );                  /* L_acc:Q20   */
   L_acc = L_sub( L_cfbg, L_acc );                     /* !!x -> L_cfbg:Q20 */
   acc_h = extract_h( L_acc );                         /* acc_h:Q4    */
   acc_h = mult( acc_h, gcode0 );                      /* acc_h:Q[-7] */
   L_tmp = L_mult( acc_h, coef[1][0] );                /* L_tmp:Q10   */

   L_preg = L_mult( coef[0][0], best_gain[1] );        /* L_preg:Q13  */
   L_acc = L_sub( L_tmp, L_shr(L_preg,3) );            /* L_acc:Q10   */

   acc_h = extract_h( L_shl( L_acc,2 ) );              /* acc_h:Q[-4] */
   L_tmp_y = L_mult( acc_h, INV_COEF );                /* L_tmp_y:Q16 */

   sft_y = (14+4+1)-16;         /* (Q[thr1]+Q[gcode0]+1)-Q[L_tmp_y] */
   sft_x = (15+4+1)-15;         /* (Q[thr2]+Q[gcode0]+1)-Q[L_tmp_x] */

   if(gcode0>0){
      /*-- pre select codebook #1 --*/
      *cand1 = 0 ;
      do{
         L_temp = L_sub( L_tmp_y, L_shr(L_mult(thr1[*cand1],gcode0),sft_y));
         if(L_temp >0L  ){
        (*cand1) =add(*cand1,1);
     }
         else               break ;
      } while(sub((*cand1),(NCODE1-NCAN1))<0) ;
      /*-- pre select codebook #2 --*/
      *cand2 = 0 ;
      do{
        L_temp = L_sub( L_tmp_x , L_shr(L_mult(thr2[*cand2],gcode0),sft_x));
         if( L_temp >0L) {
        (*cand2) =add(*cand2,1);
     }
         else               break ;
      } while(sub((*cand2),(NCODE2-NCAN2))<0) ;
   }
   else{
      /*-- pre select codebook #1 --*/
      *cand1 = 0 ;
      do{
        L_temp = L_sub(L_tmp_y ,L_shr(L_mult(thr1[*cand1],gcode0),sft_y));
         if( L_temp <0L){
        (*cand1) =add(*cand1,1);
     }
         else               break ;
      } while(sub((*cand1),(NCODE1-NCAN1))) ;
      /*-- pre select codebook #2 --*/
      *cand2 = 0 ;
      do{
         L_temp =L_sub(L_tmp_x ,L_shr(L_mult(thr2[*cand2],gcode0),sft_x));
         if( L_temp <0L){
        (*cand2) =add(*cand2,1);
     }
         else               break ;
      } while(sub( (*cand2),(NCODE2-NCAN2))) ;
   }

   return ;
}