function [error_code error_mess sig_ECGout signal_levels sig_level baseline_level ac_level baseline_correlation]=prepECG(sig_ECGin);
%-------------------------------------------
% preFILT1 - BASELINE AND AC FILTER DATA (ENTIRE SIGNAL)
%-------------------------------------------
sig_ECGout=zeros(size(sig_ECGin));
bfiltfrek=0.9; % maybe higher for short signals
[B1,A1]=butter(3,bfiltfrek/50);
[B2,A2]=butter(4,[48 52]/500,'stop');% maybe add harmonics
[B3,A3]=butter(4,[58 62]/500,'stop');% maybe add harmonics
block_AMP=2000;
block_BASE=100;
dylenAMP = floor(size(sig_ECGout,2)/block_AMP);
dylenBASE = floor(size(sig_ECGout,2)/block_BASE);
Ecg100 = zeros(size(sig_ECGin,1), ceil(length(sig_ECGin(1,1:2:end))/5));
baseline_level = zeros(1,size(sig_ECGin,1));
ac_level = zeros(size(sig_ECGin,1),1);
sig_level = zeros(size(sig_ECGin,1),4);
leads=size(sig_ECGin,1);
for lead=1:size(sig_ECGin,1)
Ecg100(lead,:)=decimate(sig_ECGin(lead,1:2:end),5);
Baseline=filtfilt(B1,A1,Ecg100(lead,:));
Baseline=interp(Baseline,10);
baseline_level(lead)=std(Baseline);
sig_ECGout(lead,:)=sig_ECGin(lead,:)-Baseline(1:size(sig_ECGin,2));
tmp=sig_ECGout(lead,:);
sig_ECGout(lead,:)=filtfilt(B2,A2,sig_ECGout(lead,:)); %
ac_level(lead,1)=std(sig_ECGout(lead,:)-tmp);
tmp=sig_ECGout(lead,:);
sig_ECGout(lead,:)=filtfilt(B3,A3,sig_ECGout(lead,:)); %
ac_level(lead,2)=std(sig_ECGout(lead,:)-tmp);
DynamicsP=zeros(1,dylenAMP);
DynamicsN=zeros(1,dylenAMP);
for i=1:floor(size(sig_ECGout,2)/block_AMP)
idx = (i-1)*block_AMP+1:i*block_AMP;
DynamicsP(i)=max(sig_ECGout(lead,idx));
DynamicsN(i)=min(sig_ECGout(lead,idx));
end;
DynbaseP=zeros(1,dylenBASE);
DynbaseN=zeros(1,dylenBASE);
for i=1:floor(size(sig_ECGout,2)/block_BASE)
idx = (i-1)*block_BASE+1:i*block_BASE;
DynbaseP(i)=max(sig_ECGout(lead,idx));
DynbaseN(i)=min(sig_ECGout(lead,idx));
end;
Dynbase=DynbaseP-DynbaseN;
tmpz=zeros(size(sig_ECGout(lead,:)));
tmpz(sig_ECGout(lead,:)>3*median(DynamicsP(find(DynamicsP>1))))=1;
tmpz(sig_ECGout(lead,:)<3*median(DynamicsN(find(abs(DynamicsN)>1))))=1;
tmpz=filtfilt(1/175.* ones(1,175),1,tmpz);
sig_ECGout(lead,tmpz>0)=0;
sig_level(lead,1)=median(DynamicsP(find(DynamicsP>1)));
sig_level(lead,2)=median(DynamicsN(find(abs(DynamicsN)>1)));
if sum(DynbaseP>1)>0
sig_level(lead,3)=prctile(DynbaseP(find(DynbaseP)),20);
else
sig_level(lead,3)=NaN;
end;
if sum(Dynbase>1)>0
sig_level(lead,4)=prctile(Dynbase(find(Dynbase>1)),20);
else
sig_level(lead,4)=NaN;
end;
sig_ECGout(lead,:)=filtfilt(0.05*ones(20,1),1,sig_ECGout(lead,:));
if lead==1
sig_ECGcut=sig_ECGout(1,:);
sig_ECGcut(sig_ECGcut>sig_level(1,3))=sig_level(1,3);
sig_ECGcut(sig_ECGcut<(sig_level(1,3)-sig_level(1,4)))=sig_level(1,3)-sig_level(1,4);
Y1=xcorr(sig_ECGcut,'unbiased');
[MaxPos1 MaxVal1]=locmax(Y1);
MaxPos1=MaxPos1(MaxVal1>0);
MaxVal1=MaxVal1(MaxVal1>0);
if length(MaxPos1)>1
baseline_correlation.maincycle=MaxPos1(ceil(length(MaxPos1)/2)+1)-MaxPos1(ceil(length(MaxPos1)/2));%Avstånd mellan main peak och second peak i corrsig.
baseline_correlation.maincyclecorr=MaxVal1(ceil(length(MaxPos1)/2)+1)/MaxVal1(ceil(length(MaxPos1)/2)); %Amplitud ratio
baseline_correlation.partclosetomc=length(find(abs(diff(MaxPos1)-baseline_correlation.maincycle)<20))/length(diff(MaxPos1)); % andel av korrpeakar som passar med flength.
else
baseline_correlation.maincycle=NaN;
baseline_correlation.maincyclecorr=NaN;
baseline_correlation.partclosetomc=NaN;
end;
end; %lead==1
end;%lead
signal_levels=[mean(baseline_level) mean(ac_level,1) mean(sig_level,1) sig_level(1,3) sig_level(1,4)];
leads_normalbeatrange=find(sig_level(1:min(leads,3),1)<10000 & sig_level(1:min(leads,3),2)>-10000 & (sig_level(1:min(leads,3),1)-sig_level(1:min(leads,3),2))<12000 & (sig_level(1:min(leads,3),1)-sig_level(1:min(leads,3),2))>200);
if length(leads_normalbeatrange)<min(leads,3);
error_code=103;
error_mess='103 (A.2) - Unexpected beat range (some of leads 1-3)';
return
end;
if (sig_level(1:min(leads,3),3)-sig_level(1:min(leads,3),4))>0.5*(sig_level(1:min(leads,3),1)-sig_level(1:min(leads,3),2))
error_code=104;
error_mess='104 (A.2) - Baseline larger than 50% of beat range (some of leads 1-3)';
return
end;
error_code=0;
error_mess='';