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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 : DE_ACELP.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" 
#else 
 #include "ld8k.h" 
#endif 
 
/*-----------------------------------------------------------* 
 *  Function  decod_ACELP()                                  * 
 *  ~~~~~~~~~~~~~~~~~~~~~~~                                  * 
 *   Algebraic codebook decoder.                             * 
 *----------------------------------------------------------*/ 
 
void decod_ACELP( 
 int sign,              /* input : signs of 4 pulses     */ 
 int index,             /* input : positions of 4 pulses */ 
 FLOAT cod[]            /* output: innovative codevector */ 
) 
{ 
   int pos[4]; 
   int i, j; 
 
   /* decode the positions of 4 pulses */ 
 
   i = index & 7; 
   pos[0] = i*5; 
 
   index >>= 3; 
   i = index & 7; 
   pos[1] = i*5 + 1; 
 
   index >>= 3; 
   i = index & 7; 
   pos[2] = i*5 + 2; 
 
   index >>= 3; 
   j = index & 1; 
   index >>= 1; 
   i = index & 7; 
   pos[3] = i*5 + 3 + j; 
 
   /* find the algebraic codeword */ 
 
   for (i = 0; i < L_SUBFR; i++) cod[i] = 0; 
 
   /* decode the signs of 4 pulses */ 
 
   for (j=0; j<4; j++) 
   { 
 
     i = sign & 1; 
     sign >>= 1; 
 
     if (i != 0) { 
       cod[pos[j]] = (F)1.0; 
     } 
     else { 
       cod[pos[j]] = (F)-1.0; 
     } 
   } 
 
   return; 
}