WSJT-X/lib/symspec.f90
Bill Somerville 5b43b691f3 Restructuring in preparation for direct decoder invocation from wsjtx
Re-factor the JT4, JT65 and JT9 decoders as Fortran modules using type
bound  procedures, the  decoder types  implement a  callback procedure
such that he client of the decoder can interpret the decode results as
they need.

The JT4 decoder has a  second callback that delivers message averaging
status.  Also the  previously separate  source files  lib/jt4a.f90 and
lib/avg4.f90 have been merged  into lib/jt4_decode.f90 as private type
bound procedures of the new jt4_decoder type.

Re-factored the lib/decoder.f90 subroutine  to utilize the new decoder
types. Added local procedures to process decodes and averaging results
including the necessary OpenMP synchronization directives for parallel
JT9+JT65 decoding.

Added the  jt65_test module  which is  a basic  test harness  for JT65
decoding. Re-factored  the jt65 utility  to utilize the  new jt65_test
module.

Changed a  few integers  to logical variables  where their  meaning is
clearly binary.

git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@6324 ab8295b8-cf94-4d9e-aec4-7959e3be5d79
2015-12-29 23:52:55 +00:00

125 lines
3.3 KiB
Fortran

subroutine symspec(shared_data,k,ntrperiod,nsps,ingain,nminw,pxdb,s, &
df3,ihsym,npts8)
! Input:
! k pointer to the most recent new data
! ntrperiod T/R sequence length, minutes
! nsps samples per symbol, at 12000 Hz
! ndiskdat 0/1 to indicate if data from disk
! nb 0/1 status of noise blanker (off/on)
! nbslider NB setting, 0-100
! Output:
! pxdb power (0-60 dB)
! s() current spectrum for waterfall display
! ihsym index number of this half-symbol (1-184) for 60 s modes
! jt9com
! ss() JT9 symbol spectra at half-symbol steps
! savg() average spectra for waterfall display
use, intrinsic :: iso_c_binding, only: c_int, c_short, c_float, c_char
include 'jt9com.f90'
type(dec_data) :: shared_data
real*4 w3(MAXFFT3)
real*4 s(NSMAX)
real*4 ssum(NSMAX)
real*4 xc(0:MAXFFT3-1)
real*4 tmp(NSMAX)
complex cx(0:MAXFFT3/2)
integer nch(7)
common/jt9w/syellow(NSMAX)
data rms/999.0/,k0/99999999/,nfft3z/0/
data nch/1,2,4,9,18,36,72/
equivalence (xc,cx)
save
if(ntrperiod.eq.-999) stop !Silence compiler warning
nfft3=16384 !df=12000.0/16384 = 0.732422
jstep=nsps/2 !Step size = half-symbol in id2()
if(k.gt.NMAX) go to 900
if(k.lt.2048) then !(2048 was nfft3) (Any need for this ???)
ihsym=0
go to 900 !Wait for enough samples to start
endif
if(nfft3.ne.nfft3z) then
! Compute new window
pi=4.0*atan(1.0)
width=0.25*nsps
do i=1,nfft3
z=(i-nfft3/2)/width
w3(i)=exp(-z*z)
enddo
nfft3z=nfft3
endif
if(k.lt.k0) then !Start a new data block
ja=0
ssum=0.
ihsym=0
if(.not. shared_data%params%ndiskdat) shared_data%id2(k+1:)=0 !Needed to prevent "ghosts". Not sure why.
endif
gain=10.0**(0.1*ingain)
sq=0.
do i=k0+1,k
x1=shared_data%id2(i)
sq=sq + x1*x1
enddo
sq=sq * gain
rms=sqrt(sq/(k-k0))
pxdb=0.
if(rms.gt.0.0) pxdb=20.0*log10(rms)
if(pxdb.gt.60.0) pxdb=60.0
k0=k
ja=ja+jstep !Index of first sample
fac0=0.1
do i=0,nfft3-1 !Copy data into cx
j=ja+i-(nfft3-1)
xc(i)=0.
if(j.ge.1 .and.j.le.NMAX) xc(i)=fac0*shared_data%id2(j)
enddo
ihsym=ihsym+1
xc(0:nfft3-1)=w3(1:nfft3)*xc(0:nfft3-1) !Apply window w3
call four2a(xc,nfft3,1,-1,0) !Real-to-complex FFT
df3=12000.0/nfft3 !JT9-1: 0.732 Hz = 0.42 * tone spacing
iz=min(NSMAX,nint(5000.0/df3))
fac=(1.0/nfft3)**2
do i=1,iz
j=i-1
if(j.lt.0) j=j+nfft3
sx=fac*(real(cx(j))**2 + aimag(cx(j))**2)
if(ihsym.le.184) shared_data%ss(ihsym,i)=sx
ssum(i)=ssum(i) + sx
s(i)=1000.0*gain*sx
enddo
shared_data%savg=ssum/ihsym
if(mod(ihsym,10).eq.0) then
mode4=nch(nminw+1)
nsmo=min(10*mode4,150)
nsmo=4*nsmo
call flat1(shared_data%savg,iz,nsmo,syellow)
if(mode4.ge.2) call smo(syellow,iz,tmp,mode4)
if(mode4.ge.2) call smo(syellow,iz,tmp,mode4)
syellow(1:250)=0.
ia=500./df3
ib=2700.0/df3
smin=minval(syellow(ia:ib))
smax=maxval(syellow(1:iz))
syellow=(50.0/(smax-smin))*(syellow-smin)
where(syellow<0) syellow=0.
endif
900 npts8=k/8
return
end subroutine symspec