ffdshow raw for deinterlacing isn't needed anymore.
madvr supports broader gpu deinterlacing now.
and if that gives problems for whatever reason, lav video can now do cpu deinterlacing.
wmvideo decoder dmo is probably the best solution now. Maybe that will change in the future, they are adding interlaced vc-1 decoding to libavcodec (the software vc-1 decoder lav uses). When that happens, we can probably stop using the microsoft decoder.