mirror of https://github.com/saitohirga/WSJT-X.git
120 lines
3.9 KiB
Fortran
120 lines
3.9 KiB
Fortran
subroutine jtmsk_decode(id2,narg,line)
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! Decoder for JTMSK mode
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parameter (NMAX=30*12000)
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parameter (NFFTMAX=512*1024)
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parameter (NSPM=1404) !Samples per JTMSK long message
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integer*2 id2(0:NMAX) !Raw i*2 data, up to T/R = 30 s
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integer hist(0:32868)
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real d(0:NMAX) !Raw r*4 data
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real ty(NMAX/512) !Ping times
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real yellow(NMAX/512)
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complex c(NFFTMAX) !Complex (analytic) data
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complex cdat(24000) !Short segments, up to 2 s
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complex cdat2(24000)
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integer narg(0:14) !Arguments passed from calling pgm
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character*22 msg,msg0 !Decoded message
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character*80 line(100) !Decodes passed back to caller
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equivalence (hist,d)
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! Parameters from GUI are in narg():
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nutc=narg(0) !UTC
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npts=min(narg(1),NMAX) !Number of samples in id2 (12000 Hz)
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newdat=narg(3) !1==> new data, compute symbol spectra
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minsync=narg(4) !Lower sync limit
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npick=narg(5)
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t0=0.001*narg(6)
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t1=0.001*narg(7)
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maxlines=narg(8) !Max # of decodes to return to caller
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nmode=narg(9)
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nrxfreq=narg(10) !Target Rx audio frequency (Hz)
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ntol=narg(11) !Search range, +/- ntol (Hz)
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nhashcalls=narg(12)
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naggressive=narg(14)
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nsnr0=-99
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nline=0
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line(1:100)(1:1)=char(0)
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msg0=' '
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msg=msg0
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hist=0
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do i=0,npts-1
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n=abs(id2(i))
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hist(n)=hist(n)+1
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enddo
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ns=0
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do n=0,32768
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ns=ns+hist(n)
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if(ns.gt.npts/2) exit
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enddo
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fac=1.0/(1.5*n)
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d(0:npts-1)=fac*id2(0:npts-1)
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! rms=sqrt(dot_product(d(0:npts-1),d(0:npts-1))/npts)
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!### Would it be better to set median rms to 1.0 ?
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! d(0:npts-1)=d(0:npts-1)/rms !Normalize so that rms=1.0
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call mskdt(d,npts,ty,yellow,nyel)
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nyel=min(nyel,5)
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n=log(float(npts))/log(2.0) + 1.0
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nfft=min(2**n,1024*1024)
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call analytic(d,npts,nfft,c) !Convert to analytic signal and filter
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nbefore=NSPM
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nafter=4*NSPM
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! Process ping list (sorted by S/N) from top down.
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do n=1,nyel
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ia=ty(n)*12000.0 - nbefore
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if(ia.lt.1) ia=1
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ib=ia + nafter
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if(ib.gt.NFFTMAX) ib=NFFTMAX
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iz=ib-ia+1
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cdat2(1:iz)=c(ia:ib) !Select nlen complex samples
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ja=ia/NSPM + 1
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jb=ib/NSPM
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t0=ia/12000.0
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do itry=1,21
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idf1=(itry/2) * 50
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if(mod(itry,2).eq.1) idf1=-idf1
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if(abs(idf1).gt.ntol) exit
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fpk=idf1 + nrxfreq
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call tweak1(cdat2,iz,1500.0-fpk,cdat)
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call syncmsk(cdat,iz,jpk,ipk,idf,rmax,snr,metric,msg)
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if(metric.eq.-9999) cycle !No output if no significant sync
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if(msg(1:1).eq.' ') call jtmsk_short(cdat,iz,narg,tbest,idfpk,msg)
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if(msg(1:1).eq.'<' .and. naggressive.eq.0 .and. &
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narg(13)/8.ne.narg(12)) msg=' '
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if(msg(1:1).ne.' ') then
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if(msg.ne.msg0) then
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nline=nline+1
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nsnr0=-99
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endif
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freq=fpk+idf
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t0=(ia+jpk)/12000.0
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y=10.0**(0.1*(yellow(n)-1.5))
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nsnr=max(-5,nint(db(y)))
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if(nsnr.gt.nsnr0 .and. nline.gt.0) then
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call rectify_msk(cdat2(jpk:jpk+NSPM-1),msg,narg(13),freq2)
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freq=freq2
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if(msg(1:1).eq.'<') freq=freq2+idfpk
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!### Check freq values !!!
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write(line(nline),1020) nutc,nsnr,t0,nint(freq),msg
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1020 format(i6.6,i4,f5.1,i5,' & ',a22)
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nsnr0=nsnr
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go to 900
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endif
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msg0=msg
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if(nline.ge.maxlines) go to 900
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endif
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enddo
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! print*,'c',nutc,n,nint(yellow(n)-4.0),freq,freq2
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enddo
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900 continue
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! print*,'d',nutc,n,nint(yellow(n)-4.0),freq,freq2
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if(line(1)(1:6).eq.' ') line(1)(1:1)=char(0)
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return
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end subroutine jtmsk_decode
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