mirror of
https://github.com/saitohirga/WSJT-X.git
synced 2024-09-30 09:06:38 -04:00
3dec8d4d97
git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@4558 ab8295b8-cf94-4d9e-aec4-7959e3be5d79
128 lines
3.5 KiB
Fortran
128 lines
3.5 KiB
Fortran
subroutine extract(s3,nadd,ncount,nhist,decoded,ltext,nbmkv)
|
|
|
|
! Input:
|
|
! s3 64-point spectra for each of 63 data symbols
|
|
! nadd number of spectra summed into s3
|
|
|
|
! Output:
|
|
! ncount number of symbols requiring correction
|
|
! nhist maximum number of identical symbol values
|
|
! decoded decoded message (if ncount >=0)
|
|
! ltext true if decoded message is free text
|
|
! nbmkv 0=no decode; 1=BM decode; 2=KV decode
|
|
|
|
use prog_args !shm_key, exe_dir, data_dir
|
|
|
|
real s3(64,63)
|
|
character decoded*22
|
|
integer era(51),dat4(12),indx(64)
|
|
integer mrsym(63),mr2sym(63),mrprob(63),mr2prob(63)
|
|
logical nokv,ltext
|
|
data nokv/.false./,nsec1/0/
|
|
save
|
|
|
|
nbmkv=0
|
|
nfail=0
|
|
|
|
! Get most reliable and second-most-reliable symbol values, and their
|
|
! probabilities
|
|
1 call demod64a(s3,nadd,mrsym,mrprob,mr2sym,mr2prob,ntest,nlow)
|
|
if(ntest.lt.50 .or. nlow.gt.20) then
|
|
ncount=-999 !Flag and reject bad data
|
|
go to 900
|
|
endif
|
|
call chkhist(mrsym,nhist,ipk) !Test for birdies and QRM
|
|
|
|
if(nhist.ge.20) then
|
|
nfail=nfail+1
|
|
call pctile(s3,4032,50,base)
|
|
do j=1,63
|
|
s3(ipk,j)=base
|
|
enddo
|
|
if(nfail.gt.30) then
|
|
decoded=' '
|
|
ncount=-1
|
|
go to 900
|
|
endif
|
|
go to 1
|
|
endif
|
|
|
|
call graycode65(mrsym,63,-1)
|
|
call interleave63(mrsym,-1)
|
|
call interleave63(mrprob,-1)
|
|
|
|
! Decode using Berlekamp-Massey algorithm
|
|
nemax=30 !Max BM erasures
|
|
call indexx(63,mrprob,indx)
|
|
do i=1,nemax
|
|
j=indx(i)
|
|
if(mrprob(j).gt.120) then
|
|
ne2=i-1
|
|
go to 2
|
|
endif
|
|
era(i)=j-1
|
|
enddo
|
|
ne2=nemax
|
|
2 decoded=' '
|
|
do nerase=0,ne2,2
|
|
call rs_decode(mrsym,era,nerase,dat4,ncount)
|
|
if(ncount.ge.0) then
|
|
call unpackmsg(dat4,decoded)
|
|
if(iand(dat4(10),8).ne.0) ltext=.true.
|
|
nbmkv=1
|
|
go to 900
|
|
endif
|
|
enddo
|
|
|
|
! Berlekamp-Massey algorithm failed, try Koetter-Vardy
|
|
|
|
if(nokv) go to 900
|
|
|
|
maxe=8 !Max KV errors in 12 most reliable symbols
|
|
! xlambda=12.0
|
|
xlambda=7.99
|
|
call graycode65(mr2sym,63,-1)
|
|
call interleave63(mr2sym,-1)
|
|
call interleave63(mr2prob,-1)
|
|
|
|
nsec1=nsec1+1
|
|
dat4=0
|
|
write(22,rec=1) nsec1,xlambda,maxe,200,mrsym,mrprob,mr2sym,mr2prob
|
|
write(22,rec=2) -1,-1,dat4
|
|
call flush(22)
|
|
call timer('kvasd ',0)
|
|
|
|
! TODO G4WJS: Take out '-q' argument once kvasd 1.12 is available for Mac and in the repo
|
|
! where CMake fetches it from.
|
|
#ifdef WIN32
|
|
iret=system('""'//trim(exe_dir)//'/kvasd" -q >dev_null"')
|
|
! iret=system('""'//trim(exe_dir)//'/kvasd" kvasd.dat >dev_null"')
|
|
#else
|
|
iret=system('"'//trim(exe_dir)//'/kvasd" -q >/dev/null')
|
|
! iret=system('"'//trim(exe_dir)//'/kvasd" kvasd.dat >/dev/null')
|
|
#endif
|
|
call timer('kvasd ',1)
|
|
if(iret.ne.0) then
|
|
if(.not.nokv) write(*,1000) iret
|
|
1000 format('Error in KV decoder, or no KV decoder present.',i12)
|
|
! nokv=.true.
|
|
go to 900
|
|
endif
|
|
|
|
read(22,rec=2,err=900) nsec2,ncount,dat4
|
|
j=nsec2 !Silence compiler warning
|
|
decoded=' '
|
|
ltext=.false.
|
|
if(ncount.ge.0) then
|
|
call unpackmsg(dat4,decoded) !Unpack the user message
|
|
if(index(decoded,'...... ').gt.0) then
|
|
ncount=-1
|
|
go to 900
|
|
endif
|
|
if(iand(dat4(10),8).ne.0) ltext=.true.
|
|
nbmkv=2
|
|
endif
|
|
|
|
900 return
|
|
end subroutine extract
|