28 lines
629 B
Fortran
28 lines
629 B
Fortran
|
subroutine wav11(d2,npts,dd)
|
||
|
|
|
||
|
|
! Convert i*2 data sampled at 12000 Hz to r*4 sampled at 11025 Hz.
|
||
|
|
|
||
|
|
parameter (NZ11=60*11025,NZ12=60*12000)
|
||
|
|
parameter (NFFT1=64*12000,NFFT2=64*11025)
|
||
|
|
integer*2 d2(NZ12)
|
||
|
|
real*4 dd(NZ11)
|
||
|
|
real x(NFFT2)
|
||
|
|
complex cx(0:NFFT1/2)
|
||
|
|
equivalence (x,cx)
|
||
|
|
save x,cx
|
||
|
|
|
||
|
|
jz=min(NZ12,npts)
|
||
|
|
x(1:jz)=d2(1:jz)
|
||
|
|
x(jz+1:)=0.0
|
||
|
|
call four2a(x,nfft1,1,-1,0) !Forward FFT, r2c
|
||
|
|
df=12000.0/NFFT1
|
||
|
|
ia=5000.0/df
|
||
|
|
cx(ia:)=0.0
|
||
|
|
call four2a(cx,nfft2,1,1,-1) !Inverse FFT, c2r
|
||
|
|
npts=jz*11025.0/12000.0
|
||
|
|
fac=1.e-6
|
||
|
|
dd(1:npts)=fac*x(1:npts)
|
||
|
|
|
||
|
|
return
|
||
|
|
end subroutine wav11
|