/***************************************************************
A.2?aec.cxx
***************************************************************/
/*?aec.cxx
?*?Acoustic?Echo?Cancellation?NLMS-pw?algorithm
?*?Author:?Andre?Adrian?DFS?Deutsche?Flugsicherung
?*?
?*
?*?Version?1.1
?*?Copyright?（C）?DFS?Deutsche?Flugsicherung?（2004）.?All?Rights?Reserved.
?*???????????（C）?Mbdsys?SARL?（2004）.
?*
?*?You?are?allowed?to?use?this?source?code?in?any?open?source?or?closed?source
?*?software?you?want.?You?are?allowed?to?use?the?algorithms?for?a?hardware
?*?solution.?You?are?allowed?to?modify?the?source?code.
?*?You?are?not?allowed?to?remove?the?name?of?the?author?from?this?memo?or?from
?*?the?source?code?files.?You?are?not?allowed?to?monopolize?the?source?code?or
?*?the?algorithms?behind?the?source?code?as?your?intellectual?property.
?*?This?source?code?is?free?of?royalty?and?comes?with?no?warranty.
?*/

#include?
#include?
#?ifdef?WIN32
#??define?_USE_MATH_DEFINES
#??include?
#??define?roundf（x）?floorf（（x）?+?0.5f）
#??ifndef?M_PI
#????define?M_PI?3.14159265358979323846
#??endif?/*?!M_PI?*/
#?else?/*?!WIN32?*/
#??include?
#?endif?/*?!WIN32?*/
#include?
#include?“aec.h“



IIR_HP6::IIR_HP6（）
{
??memset（this?0?sizeof（IIR_HP6））;
}


/*?Vector?Dot?Product?*/
float?dotp（float?a[]?float?b[]）?{
??float?sum0?=?0.0?sum1?=?0.0;
??int?j;

??for?（j?=?0;?j?????//?optimize:?partial?loop?unrolling
????sum0?+=?a[j]?*?b[j];
????sum1?+=?a[j+1]?*?b[j+1];
??}
??return?sum0+sum1;
}


/*
?*?Algorithm:??Recursive?single?pole?FIR?high-pass?filter
?*
?*?Reference:?The?Scientist?and?Engineer‘s?Guide?to?Digital?Processing
?*/

FIR1::FIR1（）
{
}

void?FIR1::init（float?preWhiteTransferAlpha）
{
??float?x?=?exp（-2.0?*?M_PI?*?preWhiteTransferAlpha）;

??a0?=?（1.0f?+?x）?/?2.0f;
??a1?=?-（1.0f?+?x）?/?2.0f;
??b1?=?x;
??last_in?=?0.0f;
??last_out?=?0.0f;
}

AEC::AEC（）
{
??hp1.init（0.01f）;??/*?10Hz?*/
??Fx.init（PreWhiteAlphaTF）;
??Fe.init（PreWhiteAlphaTF）;

??max_max_x?=?0.0f;
??hangover?=?0;
??memset（max_x?0?sizeof（max_x））;
??dtdCnt?=?dtdNdx?=?0;

??memset（x?0?sizeof（x））;
??memset（xf?0?sizeof（xf））;
??memset（w?0?sizeof（w））;
??j?=?NLMS_EXT;
??lastupdate?=?0;
??dotp_xf_xf?=?0.0f;
}


float?AEC::nlms_pw（float?mic?float?spk?int?update）
{
??float?d?=?mic;??????	????????//?desired?signal
??x[j]?=?spk;
??xf[j]?=?Fx.highpass（spk）;?????//?pre-whitening?of?x

??//?calculate?error?value?（mic?signal?-?estimated?mic?signal?from?spk?signal）
??float?e?=?d?-?dotp（w?x?+?j）;
??float?ef?=?Fe.highpass（e）;????//?pre-whitening?of?e
??if?（update）?{
????if?