This has been due for a while. The last FFTW 2.x release was in 1999.
Note that this does change some of the loops; this has two benefits:
1) The halfcomplex storage order is now explained with a comment.
2) It fixed the special case "don't break a run of bytes for a zero" which
was never triggering due to the value not being *exactly* 0.0.
I have tested these changes against older FFT-compressed animation .bams
and no noticeable decompression changes are present, so a .bam version
bump is not necessary.