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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 : POST_PRO.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 
 
/*------------------------------------------------------------------------* 
 * Function post_process()                                                 * 
 *                                                                        * 
 * Post-processing of output speech.                                      * 
 *   - 2nd order high pass filter with cut off frequency at 100 Hz.       * 
 *-----------------------------------------------------------------------*/ 
 
/*------------------------------------------------------------------------* 
 * 2nd order high pass filter with cut off frequency at 100 Hz.           * 
 * Designed with SPPACK efi command -40 dB att, 0.25 ri.                  * 
 *                                                                        * 
 * Algorithm:                                                             * 
 *                                                                        * 
 *  y[i] = b[0]*x[i] + b[1]*x[i-1] + b[2]*x[i-2]                          * 
 *                   + a[1]*y[i-1] + a[2]*y[i-2];                         * 
 *                                                                        * 
 *     b[3] = {0.93980581E+00, -0.18795834E+01,  0.93980581E+00};         * 
 *     a[3] = {0.10000000E+01, +0.19330735E+01, -0.93589199E+00};         * 
 *-----------------------------------------------------------------------*/ 
 
static FLOAT x0, x1;         /* high-pass fir memory          */ 
static FLOAT y1, y2;         /* high-pass iir memory          */ 
 
void init_post_process( void 
) 
{ 
  x0 = x1 = (F)0.0; 
  y2 = y1 = (F)0.0; 
  return; 
} 
 
void post_process( 
   FLOAT signal[],      /* (i/o)  : signal                     */ 
   int lg               /* (i)    : lenght of signal           */ 
) 
{ 
  int i; 
  FLOAT x2; 
  FLOAT y0; 
 
  for(i=0; i