WSJT-X/lib/fst280/genfst280.f90
2020-06-16 12:28:56 -05:00

104 lines
2.5 KiB
Fortran

subroutine genfst280(msg0,ichk,msgsent,msgbits,i4tone,iwspr)
! Input:
! - msg0 requested message to be transmitted
! - ichk if ichk=1, return only msgsent
! - msgsent message as it will be decoded
! - i4tone array of audio tone values, {0,1,2,3}
! - iwspr 0: (280,101)/crc24, 1: (280,74)/crc24
!
! Frame structure:
! s8 d70 s8 d70 s8
! Message duration: TxT = 164*8400/12000 = 114.8 s
use packjt77
include 'ft4s280_params.f90'
character*37 msg0
character*37 message !Message to be generated
character*37 msgsent !Message as it will be received
character*77 c77
character*24 c24
integer*4 i4tone(NN),itmp(ND)
integer*1 codeword(2*ND)
integer*1 msgbits(101),rvec(77)
integer isyncword(8)
integer ncrc24
logical unpk77_success
data isyncword/0,1,3,2,1,0,2,3/
data rvec/0,1,0,0,1,0,1,0,0,1,0,1,1,1,1,0,1,0,0,0,1,0,0,1,1,0,1,1,0, &
1,0,0,1,0,1,1,0,0,0,0,1,0,0,0,1,0,1,0,0,1,1,1,1,0,0,1,0,1, &
0,1,0,1,0,1,1,0,1,1,1,1,1,0,0,0,1,0,1/
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
i3=-1
n3=-1
call pack77(message,i3,n3,c77)
call unpack77(c77,0,msgsent,unpk77_success) !Unpack to get msgsent
msgbits=0
iwspr=0
if(i3.eq.0.and.n3.eq.6) then
iwspr=1
read(c77,'(50i1)') msgbits(1:50)
call get_crc24(msgbits,74,ncrc24)
write(c24,'(b24.24)') ncrc24
read(c24,'(24i1)') msgbits(51:74)
else
read(c77,'(77i1)') msgbits(1:77)
call get_crc24(msgbits,101,ncrc24)
write(c24,'(b24.24)') ncrc24
read(c24,'(24i1)') msgbits(78:101)
endif
if(ichk.eq.1) go to 999
if(unpk77_success) go to 2
1 msgbits=0
itone=0
msgsent='*** bad message *** '
go to 999
entry get_ft4s280_tones_from_bits(msgbits,i4tone,iwspr)
2 continue
if(iwspr.eq.0) then
call encode280_101(msgbits,codeword)
else
call encode280_74(msgbits(1:74),codeword)
endif
! Grayscale mapping:
! bits tone
! 00 0
! 01 1
! 11 2
! 10 3
do i=1,ND
is=codeword(2*i)+2*codeword(2*i-1)
if(is.le.1) itmp(i)=is
if(is.eq.2) itmp(i)=3
if(is.eq.3) itmp(i)=2
enddo
i4tone(1:8)=isyncword
i4tone(9:78)=itmp(1:70)
i4tone(79:86)=isyncword
i4tone(87:156)=itmp(71:140)
i4tone(157:164)=isyncword
999 return
end subroutine genfst280