WSJT-X/lib/jt65_decode.f90
Bill Somerville 673a140808 Use new WAV file class (BWFFile) read and write WAV files
Saved WAV files now contain some useful metadata.

git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@6383 ab8295b8-cf94-4d9e-aec4-7959e3be5d79
2016-01-11 15:00:43 +00:00

230 lines
7.5 KiB
Fortran

module jt65_decode
integer, parameter :: NSZ=3413, NZMAX=60*12000, NFFT=1000
type :: jt65_decoder
procedure(jt65_decode_callback), pointer :: callback => null()
contains
procedure :: decode
end type jt65_decoder
!
! Callback function to be called with each decode
!
abstract interface
subroutine jt65_decode_callback (this, utc, sync, snr, dt, freq, drift, &
decoded, ft, qual, candidates, tries, total_min, hard_min, aggression)
import jt65_decoder
implicit none
class(jt65_decoder), intent(inout) :: this
integer, intent(in) :: utc
real, intent(in) :: sync
integer, intent(in) :: snr
real, intent(in) :: dt
integer, intent(in) :: freq
integer, intent(in) :: drift
character(len=22), intent(in) :: decoded
integer, intent(in) :: ft
integer, intent(in) :: qual
integer, intent(in) :: candidates
integer, intent(in) :: tries
integer, intent(in) :: total_min
integer, intent(in) :: hard_min
integer, intent(in) :: aggression
end subroutine jt65_decode_callback
end interface
contains
subroutine decode(this,callback,dd0,npts,newdat,nutc,nf1,nf2,nfqso,ntol,nsubmode, &
minsync,nagain,n2pass,nrobust,ntrials,naggressive,ndepth, &
mycall,hiscall,hisgrid,nexp_decode)
! Process dd0() data to find and decode JT65 signals.
use timer_module, only: timer
include 'constants.f90'
class(jt65_decoder), intent(inout) :: this
procedure(jt65_decode_callback) :: callback
real, intent(in) :: dd0(NZMAX)
integer, intent(in) :: npts, nutc, nf1, nf2, nfqso, ntol &
, nsubmode, minsync, n2pass, ntrials, naggressive, ndepth &
, nexp_decode
logical, intent(in) :: newdat, nagain, nrobust
character(len=12), intent(in) :: mycall, hiscall
character(len=6), intent(in) :: hisgrid
real dd(NZMAX)
real ss(322,NSZ)
real savg(NSZ)
real a(5)
character*22 decoded,decoded0
type candidate
real freq
real dt
real sync
end type candidate
type(candidate) ca(300)
type accepted_decode
real freq
real dt
real sync
character*22 decoded
end type accepted_decode
type(accepted_decode) dec(50)
logical :: first_time, robust
integer h0(0:11),d0(0:11),ne(0:11)
real r0(0:11)
common/decstats/ntry65a,ntry65b,n65a,n65b,num9,numfano
common/steve/thresh0
common/test000/ncandidates,nhard_min,nsoft_min,nera_best,nrtt1000, &
ntotal_min,ntry,nq1000,npp1 !### TEST ONLY ###
! 0 1 2 3 4 5 6 7 8 9 10 11
data h0/41,42,43,43,44,45,46,47,48,48,49,49/
data d0/71,72,73,74,76,77,78,80,81,82,83,83/
! 0 1 2 3 4 5 6 7 8 9 10 11
data r0/0.70,0.72,0.74,0.76,0.78,0.80,0.82,0.84,0.86,0.88,0.90,0.90/
save
this%callback => callback
first_time=newdat
robust=nrobust
dd=dd0
ndecoded=0
do ipass=1,n2pass ! 2-pass decoding loop
first_time=.true.
if(ipass.eq.1) then !first-pass parameters
thresh0=2.5
nsubtract=1
elseif( ipass.eq.2 ) then !second-pass parameters
thresh0=2.5
nsubtract=0
endif
if(n2pass.lt.2) nsubtract=0
! if(newdat) then
call timer('symsp65 ',0)
ss=0.
call symspec65(dd,npts,ss,nhsym,savg) !Get normalized symbol spectra
call timer('symsp65 ',1)
! endif
nfa=nf1
nfb=nf2
if(naggressive.gt.0 .and. ntol.lt.1000) then
nfa=max(200,nfqso-ntol)
nfb=min(4000,nfqso+ntol)
thresh0=1.0
endif
! robust = .false.: use float ccf. Only if ncand>50 fall back to robust (1-bit) ccf
! robust = .true. : use only robust (1-bit) ccf
ncand=0
if(.not.robust) then
call timer('sync65 ',0)
call sync65(ss,nfa,nfb,naggressive,ntol,nhsym,ca,ncand,0)
call timer('sync65 ',1)
endif
if(ncand.gt.50) robust=.true.
if(robust) then
ncand=0
call timer('sync65 ',0)
call sync65(ss,nfa,nfb,naggressive,ntol,nhsym,ca,ncand,1)
call timer('sync65 ',1)
endif
call fqso_first(nfqso,ntol,ca,ncand)
nvec=ntrials
if(ncand.gt.75) then
! write(*,*) 'Pass ',ipass,' ncandidates too large ',ncand
nvec=100
endif
df=12000.0/NFFT !df = 12000.0/8192 = 1.465 Hz
mode65=2**nsubmode
nflip=1 !### temporary ###
nqd=0
decoded0=""
freq0=0.
do icand=1,ncand
freq=ca(icand)%freq
dtx=ca(icand)%dt
sync1=ca(icand)%sync
if(ipass.eq.1) ntry65a=ntry65a + 1
if(ipass.eq.2) ntry65b=ntry65b + 1
call timer('decod65a',0)
call decode65a(dd,npts,first_time,nqd,freq,nflip,mode65,nvec, &
naggressive,ndepth,mycall,hiscall,hisgrid,nexp_decode, &
sync2,a,dtx,nft,qual,nhist,decoded)
call timer('decod65a',1)
n=naggressive
rtt=0.001*nrtt1000
if(nft.lt.2) then
if(nhard_min.gt.50) cycle
if(nhard_min.gt.h0(n)) cycle
if(ntotal_min.gt.d0(n)) cycle
if(rtt.gt.r0(n)) cycle
endif
! !### Suppress false decodes in crowded HF bands ###
! if(naggressive.eq.0 .and. ntrials.le.10000) then
! if(ntry.eq.ntrials) then
! if(nhard_min.ge.42 .or. ntotal_min.ge.71) cycle
! endif
! endif
if(decoded.eq.decoded0 .and. abs(freq-freq0).lt. 3.0 .and. &
minsync.ge.0) cycle !Don't display dupes
if(decoded.ne.' ' .or. minsync.lt.0) then
if( nsubtract .eq. 1 ) then
call timer('subtr65 ',0)
call subtract65(dd,npts,freq,dtx)
call timer('subtr65 ',1)
endif
nfreq=nint(freq+a(1))
ndrift=nint(2.0*a(2))
s2db=10.0*log10(sync2) - 35 !### empirical ###
nsnr=nint(s2db)
if(nsnr.lt.-30) nsnr=-30
if(nsnr.gt.-1) nsnr=-1
ndupe=0 ! de-dedupe
do i=1, ndecoded
if(decoded==dec(i)%decoded) then
ndupe=1
exit
endif
enddo
if(ndupe.ne.1 .or. minsync.lt.0) then
if(ipass.eq.1) n65a=n65a + 1
if(ipass.eq.2) n65b=n65b + 1
ndecoded=ndecoded+1
dec(ndecoded)%freq=freq+a(1)
dec(ndecoded)%dt=dtx
dec(ndecoded)%sync=sync2
dec(ndecoded)%decoded=decoded
nqual=min(qual,9999.0)
! if(nqual.gt.10) nqual=10
if (associated(this%callback)) then
call this%callback(nutc,sync1,nsnr,dtx-1.0,nfreq,ndrift,decoded &
,nft,nqual,ncandidates,ntry,ntotal_min,nhard_min,naggressive)
end if
endif
decoded0=decoded
freq0=freq
if(decoded0.eq.' ') decoded0='*'
endif
enddo !candidate loop
if(ndecoded.lt.1) exit
enddo !two-pass loop
return
end subroutine decode
end module jt65_decode