www.pudn.com > ETSI_ES_202_212_software.rar > PostProc.c

/*===============================================================================
 *      ETSI ES 202 212   Distributed Speech Recognition
 *      Extended Advanced Front-End Feature Extraction Algorithm & Compression Algorithm
 *      Speech Reconstruction Algorithm.
 *      C-language software implementation                                      
 *      Version 1.1.1   October, 2003                                            
 *===============================================================================*/
/*-------------------------------------------------------------------------------
 *
 * FILE NAME: PostProc.c
 * PURPOSE: Apply post-processing (blind equalization) on a frame of 
 *          cepstral coefficients.
 *
 *-------------------------------------------------------------------------------*/
/*-----------------
 * File Inclusions
 *-----------------*/
#include 

#include "ParmInterface.h"
#include "PostProcExports.h"

/*------------------------
 * Definitions and Macros
 *------------------------*/
#define PP_NB_TOPOSTPROC	    (NUM_CEP_COEFF-1)
#define PP_INDEX_ENER		    (NUM_CEP_COEFF)
#define PP_MIN_ENER_POSTPROC	((X_FLOAT32) 211)
#define PP_DELTA_ENER_POSTPROC	((X_FLOAT32) 64)

struct PostProcStructX
{
  X_FLOAT32 weightLMS [PP_NB_TOPOSTPROC] ;
};


static X_FLOAT32 targetLMS [PP_NB_TOPOSTPROC] =
{
  (X_FLOAT32) -6.618909 ,
  (X_FLOAT32)  0.198269 , 
  (X_FLOAT32) -0.740308 , 
  (X_FLOAT32)  0.055132 , 
  (X_FLOAT32) -0.227086 , 
  (X_FLOAT32)  0.144280 , 
  (X_FLOAT32) -0.112451 , 
  (X_FLOAT32) -0.146940 , 
  (X_FLOAT32) -0.327466 , 
  (X_FLOAT32)  0.134571 , 
  (X_FLOAT32)  0.027884 , 
  (X_FLOAT32) -0.114905 
} ;

static X_FLOAT32 lambda = (X_FLOAT32) 0.0087890625 ;

/*------------------------
 * start of Encapsulation
 *------------------------*/
/*----------------------------------------------------------------------------
 * FUNCTION NAME: DoPostProcAlloc
 *
 * PURPOSE:       Memory allocation of post-processing structure
 *
 * INPUT:         
 *   none     
 *
 * OUTPUT:        Post-processing structure
 *
 *
 * RETURN VALUE:  Pointer to post-processing structure
 *   
 *
 *---------------------------------------------------------------------------*/
extern PostProcStructX *DoPostProcAlloc(void)
{
  PostProcStructX *newPost = calloc (1, sizeof (PostProcStructX));
  return newPost;
}

/*----------------------------------------------------------------------------
 * FUNCTION NAME: DoPostProcInit
 *
 * PURPOSE:       Initialisation of post-processing structure
 *        
 * INPUT:
 *   FEParamsX *  Pointer to front end parameter structure
 *        
 * OUTPUT:        weightLMS in post-processing structure
 *
 *
 * RETURN VALUE:
 *   none
 *
 *---------------------------------------------------------------------------*/
extern void DoPostProcInit (FEParamsX *This)
{
  X_INT16 i;
  PostProcStructX *PPX = This->PPX;
  
  for (i=0 ; iweightLMS[i] = 0;
}

/*----------------------------------------------------------------------------
 * FUNCTION NAME: DoPostProc
 *
 * PURPOSE:       Cepstral post-processing for a frame     
 *                
 * INPUT:
 *   *Coef        Pointer to cepstral coefficients
 *   FEParamsX *  Pointer to front end parameter structure
 *
 * OUTPUT:
 *   *Coef        Pointer to cepstral coefficients
 *
 * RETURN VALUE:
 *   TRUE         A frame is always output
 *
 *---------------------------------------------------------------------------*/
extern BOOLEAN DoPostProc (X_FLOAT32 *Coef, FEParamsX *This) 
{
  X_INT16 i;
  X_FLOAT32 weightingPar;
  PostProcStructX *PPX = This->PPX;
  weightingPar = (Coef[PP_INDEX_ENER] * PP_DELTA_ENER_POSTPROC - PP_MIN_ENER_POSTPROC) / PP_DELTA_ENER_POSTPROC;
  
  if (weightingPar < 0)
	{
	  weightingPar = 0;
	} 
  else 
	if (weightingPar > 1) 
	  {
		weightingPar = lambda;
	  } 
	else 
	  {
		weightingPar *= lambda;
	  }
	
  for (i=0 ; iweightLMS[i]) - targetLMS[i]);
	  Coef[i] = Coef[i] - PPX->weightLMS[i];
	  val = dif * weightingPar;		
	  PPX->weightLMS[i] += val;
	}

  return TRUE;
}

/*----------------------------------------------------------------------------
 * FUNCTION NAME: DoPostProcDelete
 *
 * PURPOSE:       Memory free of post-processing structure
 *
 * INPUT:
 *   *PPX         Pointer to post-processing structure     
 *
 * OUTPUT:
 *   none
 *
 * RETURN VALUE:
 *   none
 *
 *---------------------------------------------------------------------------*/
extern void DoPostProcDelete (PostProcStructX *PPX)
{
  if (PPX != NULL)
	{
	  free (PPX);
    }
}