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/* 
   ITU-T G.729 Annex C+ - Reference C code for floating point 
                         implementation of G.729 Annex C+ 
                         (integration of Annexes B, D and E) 
                          Version 2.1 of October 1999 
*/ 
                                    
/* 
 File : QSIDGAIN.C 
*/ 
 
/* Quantize SID gain                                      */ 
 
#include  
#include  
#include  
 
#include "typedef.h" 
#include "ld8k.h" 
#include "vad.h" 
#include "dtx.h" 
#include "sid.h" 
#include "tab_dtx.h" 
 
/* Local function */ 
static int quant_Energy( 
    FLOAT ener,    /* (i)  : Energy                 */ 
    FLOAT *enerq   /* (o)  : quantized energy in dB */ 
); 
 
/*-------------------------------------------------------------------* 
* Function  Qua_Sidgain                                             * 
*           ~~~~~~~~~~~                                             * 
*-------------------------------------------------------------------*/ 
void qua_Sidgain( 
    FLOAT *ener,     /* (i)   array of energies                   */ 
    int nb_ener,     /* (i)   number of energies or               */ 
    FLOAT *enerq,    /* (o)   decoded energies in dB              */ 
    int *idx       /* (o)   SID gain quantization index         */ 
) 
{ 
    int i; 
    FLOAT avr_ener; 
     
    if(nb_ener == 0) { 
        /* Quantize energy saved for frame erasure case                */ 
        avr_ener = (*ener) * fact[0]; 
    } 
     
    else { 
         
    /* 
    * Compute weighted average of energies 
    * avr_ener = fact[nb_ener] x SUM(i=0->nb_ener-1) ener[i] 
    * with fact[nb_ener] =  fact_ener / nb_ener x L_FRAME x nbAcf 
        */ 
        avr_ener = (F)0.; 
        for(i=0; i -8dB */ 
        *enerq = (F)-12.; 
        return(0); 
    } 
     
    ener_dB = (F)10. * (FLOAT)log10(ener); 
     
    if(ener_dB <= (F)-8.) { 
        *enerq = (F)-12.; 
        return(0); 
    } 
     
    if(ener_dB >= (F)65.) { 
        *enerq = (F)66.; 
        return(31); 
    } 
     
    if(ener_dB <= (F)14.) { 
        index = (int)((ener_dB + (F)10.) * 0.25); 
        if (index < 1) index = 1; 
        *enerq = (F)4. * (FLOAT)index - (F)8.; 
        return(index); 
    } 
     
    index = (int)((ener_dB - (F)3.) * 0.5); 
    if (index < 6) index = 6; 
    *enerq = (F)2. * (FLOAT)index + (F)4.; 
    return(index); 
}