WSJT-X/lib/fsk4hf/genft2.f90
2019-01-16 20:55:01 +00:00

87 lines
2.3 KiB
Fortran

subroutine genft2(msg0,ichk,msgsent,i4tone,itype)
! s8 + 48bits + s8 + 80 bits = 144 bits (72ms message duration)
!
! Encode an MSK144 message
! Input:
! - msg0 requested message to be transmitted
! - ichk if ichk=1, return only msgsent
! if ichk.ge.10000, set imsg=ichk-10000 for short msg
! - msgsent message as it will be decoded
! - i4tone array of audio tone values, 0 or 1
! - itype message type
! 1 = 77 bit message
! 7 = 16 bit message "<Call_1 Call2> Rpt"
use iso_c_binding, only: c_loc,c_size_t
use packjt77
character*37 msg0
character*37 message !Message to be generated
character*37 msgsent !Message as it will be received
character*77 c77
integer*4 i4tone(144)
integer*1 codeword(128)
integer*1 msgbits(77)
integer*1 bitseq(144) !Tone #s, data and sync (values 0-1)
integer*1 s16(16)
real*8 xi(864),xq(864),pi,twopi
data s16/0,0,0,0,1,1,1,1,1,1,1,1,0,0,0,0/
equivalence (ihash,i1hash)
logical unpk77_success
nsym=128
pi=4.0*atan(1.0)
twopi=8.*atan(1.0)
message(1:37)=' '
itype=1
if(msg0(1:1).eq.'@') then !Generate a fixed tone
read(msg0(2:5),*,end=1,err=1) nfreq !at specified frequency
go to 2
1 nfreq=1000
2 i4tone(1)=nfreq
else
message=msg0
do i=1, 37
if(ichar(message(i:i)).eq.0) then
message(i:37)=' '
exit
endif
enddo
do i=1,37 !Strip leading blanks
if(message(1:1).ne.' ') exit
message=message(i+1:)
enddo
if(message(1:1).eq.'<') then
i2=index(message,'>')
i1=0
if(i2.gt.0) i1=index(message(1:i2),' ')
if(i1.gt.0) then
call genmsk40(message,msgsent,ichk,i4tone,itype)
if(itype.lt.0) go to 999
i4tone(41)=-40
go to 999
endif
endif
i3=-1
n3=-1
call pack77(message,i3,n3,c77)
call unpack77(c77,0,msgsent,unpk77_success) !Unpack to get msgsent
if(ichk.eq.1) go to 999
read(c77,"(77i1)") msgbits
call encode_128_90(msgbits,codeword)
!Create 144-bit channel vector:
bitseq=0
bitseq(1:16)=s16
bitseq(17:144)=codeword
i4tone=bitseq
endif
999 return
end subroutine genft2