subroutine encode240_74(message,codeword) use, intrinsic :: iso_c_binding use iso_c_binding, only: c_loc,c_size_t use crc integer, parameter:: N=240, K=74, M=N-K integer*1 codeword(N) integer*1 gen(M,K) integer*1 message(K) integer*1 pchecks(M) include "ldpc_240_74_generator.f90" logical first data first/.true./ save first,gen if( first ) then ! fill the generator matrix gen=0 do i=1,M do j=1,19 read(g(i)(j:j),"(Z1)") istr ibmax=4 if(j.eq.19) ibmax=2 do jj=1, ibmax icol=(j-1)*4+jj if( btest(istr,4-jj) ) gen(i,icol)=1 enddo enddo enddo first=.false. endif do i=1,M nsum=0 do j=1,K nsum=nsum+message(j)*gen(i,j) enddo pchecks(i)=mod(nsum,2) enddo codeword(1:K)=message codeword(K+1:N)=pchecks return end subroutine encode240_74