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/* ITU-T G.729 Software Package Release 2 (November 2006) */ 
/* 
   ITU-T G.729 Annex C - Reference C code for floating point 
                         implementation of G.729 
                         Version 1.01 of 15.September.98 
*/ 
 
/* 
---------------------------------------------------------------------- 
                    COPYRIGHT NOTICE 
---------------------------------------------------------------------- 
   ITU-T G.729 Annex C ANSI C source code 
   Copyright (C) 1998, AT&T, France Telecom, NTT, University of 
   Sherbrooke.  All rights reserved. 
 
---------------------------------------------------------------------- 
*/ 
/* 
 File : DEC_GAIN.C 
 Used for the floating point version of both 
 G.729 main body and G.729A 
*/ 
#include "typedef.h" 
#include "version.h" 
#ifdef VER_G729A 
 #include "ld8a.h" 
 #include "tab_ld8a.h" 
#else 
 #include "ld8k.h" 
 #include "tab_ld8k.h" 
#endif 
 
/*---------------------------------------------------------------------------- 
 * dec_gain - decode the adaptive and fixed codebook gains 
 *---------------------------------------------------------------------------- 
 */ 
void dec_gain( 
 int index,             /* input : quantizer index              */ 
 FLOAT code[],          /* input : fixed code book vector       */ 
 int l_subfr,           /* input : subframe size                */ 
 int bfi,               /* input : bad frame indicator good = 0 */ 
 FLOAT *gain_pit,       /* output: quantized acb gain           */ 
 FLOAT *gain_code       /* output: quantized fcb gain           */ 
) 
{ 
   static FLOAT past_qua_en[4]={(F)-14.0,(F)-14.0,(F)-14.0,(F)-14.0}; 
 
   int    index1,index2; 
   FLOAT  gcode0, g_code; 
 
   /*----------------- Test erasure ---------------*/ 
   if (bfi != 0) 
     { 
        *gain_pit *= (F)0.9; 
        if(*gain_pit > (F)0.9) *gain_pit=(F)0.9; 
        *gain_code *= (F)0.98; 
 
     /*----------------------------------------------* 
      * update table of past quantized energies      * 
      *                              (frame erasure) * 
      *----------------------------------------------*/ 
      gain_update_erasure(past_qua_en); 
 
        return; 
     } 
 
   /*-------------- Decode pitch gain ---------------*/ 
 
   index1 = imap1[index/NCODE2] ; 
   index2 = imap2[index%NCODE2] ; 
   *gain_pit = gbk1[index1][0]+gbk2[index2][0] ; 
 
   /*-------------- Decode codebook gain ---------------*/ 
 
  /*---------------------------------------------------* 
   *-  energy due to innovation                       -* 
   *-  predicted energy                               -* 
   *-  predicted codebook gain => gcode0[exp_gcode0]  -* 
   *---------------------------------------------------*/ 
 
   gain_predict( past_qua_en, code, l_subfr, &gcode0); 
 
  /*-----------------------------------------------------------------* 
   * *gain_code = (gbk1[indice1][1]+gbk2[indice2][1]) * gcode0;      * 
   *-----------------------------------------------------------------*/ 
 
   g_code = gbk1[index1][1]+gbk2[index2][1]; 
   *gain_code =  g_code * gcode0; 
 
  /*----------------------------------------------* 
   * update table of past quantized energies      * 
   *----------------------------------------------*/ 
 
   gain_update( past_qua_en, g_code); 
 
   return; 
}