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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_LAG3.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 dec_lag3                                                   * 
 *             ~~~~~~~~                                                   * 
 *   Decoding of fractional pitch lag with 1/3 resolution.                * 
 * See "enc_lag3.c" for more details about the encoding procedure.        * 
 *------------------------------------------------------------------------*/ 
 
void dec_lag3(     /* Decode the pitch lag                   */ 
  int index,       /* input : received pitch index           */ 
  int pit_min,     /* input : minimum pitch lag              */ 
  int pit_max,     /* input : maximum pitch lag              */ 
  int i_subfr,     /* input : subframe flag                  */ 
  int *T0,         /* output: integer part of pitch lag      */ 
  int *T0_frac     /* output: fractional part of pitch lag   */ 
) 
{ 
  int i; 
  int T0_min, T0_max; 
 
  if (i_subfr == 0)                  /* if 1st subframe */ 
  { 
    if (index < 197) 
    { 
       *T0 = (index+2)/3 + 19; 
       *T0_frac = index - *T0*3 + 58; 
    } 
    else 
    { 
      *T0 = index - 112; 
      *T0_frac = 0; 
    } 
  } 
 
  else  /* second subframe */ 
  { 
    /* find T0_min and T0_max for 2nd subframe */ 
 
    T0_min = *T0 - 5; 
    if (T0_min < pit_min) 
      T0_min = pit_min; 
 
    T0_max = T0_min + 9; 
    if(T0_max > pit_max) 
    { 
      T0_max = pit_max; 
      T0_min = T0_max -9; 
    } 
 
    i = (index+2)/3 - 1; 
    *T0 = i + T0_min; 
    *T0_frac = index - 2 - i*3; 
  } 
  return; 
}