WSJT-X/lib/decoder.f90
Joe Taylor 4fea8ebd0c Optimizations of JT9 and JT65 decoders; change clock in timer routine.
Both decoders now have slightly better performance and faster
execution.  The rare "duplicate decodes" in JT9 were eliminated.
On Windows, at least, calls to f90 routine system_clock() do not
provide correct wall time increments.  Changed to using secnds()
instead.


git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@4571 ab8295b8-cf94-4d9e-aec4-7959e3be5d79
2014-10-30 19:29:16 +00:00

192 lines
4.9 KiB
Fortran

subroutine decoder(ss,id2)
! Decoder for JT9.
use prog_args
include 'constants.f90'
real ss(184,NSMAX)
character*22 msg
character*20 datetime
real*4 ccfred(NSMAX)
real*4 red2(NSMAX)
logical ccfok(NSMAX)
logical done(NSMAX)
logical done65,baddata
integer*2 id2(NTMAX*12000)
real*4 dd(NTMAX*12000)
integer*1 i1SoftSymbols(207)
common/npar/nutc,ndiskdat,ntrperiod,nfqso,newdat,npts8,nfa,nfsplit,nfb, &
ntol,kin,nzhsym,nsave,nagain,ndepth,ntxmode,nmode,datetime
common/tracer/limtrace,lu
save
nfreqs0=0
nfreqs1=0
ndecodes0=0
ndecodes1=0
if (nagain .eq. 0) then
open(13,file='decoded.txt',status='unknown')
else
open(13,file='decoded.txt',status='unknown',position='append')
end if
open(22,file='kvasd.dat',access='direct',recl=1024,status='unknown')
npts65=52*12000
if(baddata(id2,npts65)) then
nsynced=0
ndecoded=0
go to 800
endif
ntol65=20
done65=.false.
if((nmode.eq.65 .or. nmode.eq.65+9) .and. ntxmode.eq.65) then
! We're decoding JT65, and should do this mode first
if(newdat.ne.0) dd(1:npts65)=id2(1:npts65)
nf1=nfa
nf2=nfb
! if(nmode.eq.65+9) nf2=nfsplit
call jt65a(dd,npts65,newdat,nutc,nf1,nf2,nfqso,ntol65,nagain,ndecoded)
done65=.true.
endif
if(nmode.eq.65) go to 800
nsynced=0
ndecoded=0
nsps=0
nsps=6912 !Params for JT9-1
df3=1500.0/2048.0
tstep=0.5*nsps/12000.0 !Half-symbol step (seconds)
done=.false.
nf0=0
nf1=nfa
if(nmode.eq.65+9) nf1=nfsplit
ia=max(1,nint((nf1-nf0)/df3))
ib=min(NSMAX,nint((nfb-nf0)/df3))
lag1=-(2.5/tstep + 0.9999)
lag2=5.0/tstep + 0.9999
if(newdat.ne.0) then
call timer('sync9 ',0)
call sync9(ss,nzhsym,lag1,lag2,ia,ib,ccfred,red2,ipk)
call timer('sync9 ',1)
endif
nsps8=nsps/8
df8=1500.0/nsps8
dblim=db(864.0/nsps8) - 26.2
do nqd=1,0,-1
limit=5000
ccflim=3.0
red2lim=1.6
schklim=2.2
if(ndepth.eq.2) then
limit=10000
ccflim=2.7
endif
if(ndepth.ge.3 .or. nqd.eq.1) then
limit=100000
ccflim=2.5
endif
ccfok=.false.
if(nqd.eq.1) then
nfa1=nfqso-ntol
nfb1=nfqso+ntol
ia=max(1,nint((nfa1-nf0)/df3))
ib=min(NSMAX,nint((nfb1-nf0)/df3))
ccfok(ia:ib)=(ccfred(ia:ib).gt.(ccflim-2.0)) .and. &
(red2(ia:ib).gt.(red2lim-1.0))
ia1=ia
ib1=ib
else
nfa1=nf1
nfb1=nfb
ia=max(1,nint((nfa1-nf0)/df3))
ib=min(NSMAX,nint((nfb1-nf0)/df3))
do i=ia,ib
ccfok(i)=ccfred(i).gt.ccflim .and. red2(i).gt.red2lim
enddo
ccfok(ia1:ib1)=.false.
endif
fgood=0.
do i=ia,ib
if(done(i) .or. (.not.ccfok(i))) cycle
f=(i-1)*df3
if(nqd.eq.1 .or. &
(ccfred(i).ge.ccflim .and. abs(f-fgood).gt.10.0*df8)) then
if(nqd.eq.0) nfreqs0=nfreqs0+1
if(nqd.eq.1) nfreqs1=nfreqs1+1
call timer('softsym ',0)
fpk=nf0 + df3*(i-1)
call softsym(id2,npts8,nsps8,newdat,fpk,syncpk,snrdb,xdt, &
freq,drift,schk,i1SoftSymbols)
call timer('softsym ',1)
sync=(syncpk+1)/4.0
if(maxval(i1SoftSymbols).eq.0) cycle
if(nqd.eq.1 .and. ((sync.lt.0.5) .or. (schk.lt.2.0))) cycle
if(nqd.ne.1 .and. ((sync.lt.1.0) .or. (schk.lt.schklim))) cycle
call timer('decode9 ',0)
call decode9(i1SoftSymbols,limit,nlim,msg)
call timer('decode9 ',1)
if(sync.lt.0.0 .or. snrdb.lt.dblim-2.0) sync=0.0
nsync=sync
if(nsync.gt.10) nsync=10
nsnr=nint(snrdb)
ndrift=nint(drift/df3)
if(msg.ne.' ') then
if(nqd.eq.0) ndecodes0=ndecodes0+1
if(nqd.eq.1) ndecodes1=ndecodes1+1
write(*,1000) nutc,nsnr,xdt,nint(freq),msg
1000 format(i4.4,i4,f5.1,i5,1x,'@',1x,a22)
write(13,1002) nutc,nsync,nsnr,xdt,freq,ndrift,msg
1002 format(i4.4,i4,i5,f6.1,f8.0,i4,3x,a22,' JT9')
iaa=max(1,i-1)
ibb=min(NSMAX,i+22)
fgood=f
nsynced=1
ndecoded=1
ccfok(iaa:ibb)=.false.
done(iaa:ibb)=.true.
call flush(6)
endif
endif
enddo
call flush(6)
if(nagain.ne.0) exit
enddo
if(nmode.ge.65 .and. (.not.done65)) then
if(newdat.ne.0) dd(1:npts65)=id2(1:npts65)
nf1=nfa
nf2=nfb
call jt65a(dd,npts65,newdat,nutc,nf1,nf2,nfqso,ntol65,nagain,ndecoded)
endif
! JT65 is not yet producing info for nsynced, ndecoded.
800 write(*,1010) nsynced,ndecoded
1010 format('<DecodeFinished>',2i4)
call flush(6)
close(13)
close(22)
return
end subroutine decoder