WSJT-X/libm65/genjt9.f90

subroutine genjt9(message,minutes,msgsent,d6)

! Encodes a "JT9-minutes" message and returns array d6(85) of tone
! values in the range 0-8.  

  character*22 message          !Message to be generated
  character*22 msgsent          !Message as it will be received

  integer*4 d0(13)              !72-bit message as 6-bit words
  integer*1 d1(13)              !72 bits and zero tail as 8-bit bytes
  integer*1 d2(206)             !Encoded information-carrying bits
  integer*1 d3(206)             !Bits from d2, after interleaving
  integer*4 d4(69)              !Symbols from d3, values 0-7
  integer*4 d5(69)              !Gray-coded symbols, values 0-7
  integer*4 d6(85)              !Channel symbols including sync, values 0-8

  integer*4 t0(13)              !72-bit message as 6-bit words
  integer*1 t1(13)              !72 bits and zero tail as 8-bit bytes
  integer*1 t2(206)             !Encoded information-carrying bits
  integer*1 t3(206)             !Bits from d2, after interleaving
  integer*4 t4(69)              !Symbols from d3, values 0-7
  integer*4 t5(69)              !Gray-coded symbols, values 0-7
  integer*4 t6(85)              !Channel symbols including sync, values 0-8

  integer isync(85)
  data isync/                                    &
       1,0,0,0,0,1,0,0,0,0,1,0,0,0,0,1,0,0,0,0,  &
       1,0,0,0,0,1,0,0,0,0,1,0,0,0,0,0,0,0,1,0,  &
       0,0,0,0,1,0,0,0,0,0,1,0,0,0,0,0,1,0,0,0,  &
       0,0,1,0,0,0,0,0,1,0,0,0,0,0,1,0,0,0,0,0,  &
       1,0,0,0,1/
  data twopi/6.283185307179586476d0/
  save

  call packmsg(message,d0)           !Pack message into 12 6-bit bytes
  call unpackmsg(d0,msgsent)
  call entail(d0,d1)
  nsym2=206
  call encode232(d1,nsym2,d2)        !Convolutional code, K=32, r=1/2
  call interleave9(d2,1,d3)
  call packbits(d3,nsym2,3,d4)
  call graycode(d4,69,1,d5)

! Insert sync symbols (ntone=0) and add 1 to the data-tone numbers.
  j=0
  do i=1,85
     if(isync(i).eq.1) then
        d6(i)=0
     else
        j=j+1
        d6(i)=d5(j)+1
     endif
  enddo

!  t6=d6
!  j=0
!  do i=1,85
!     if(isync(i).eq.1) cycle
!     j=j+1
!     t5(j)=t6(i)-1
!  enddo

!  call graycode(t5,69,-1,t4)
!  call unpackbits(t4,nsym2,3,t3)
!  call interleave9(t3,-1,t2)
!  print*,'A',d2-t2

  return
end subroutine genjt9