FFmpeg removing pulldown from DVD source

[BlueTech]

I'm trying to convert some DVD source MPEG-2 videos to ProRes that are 23.976fps (as reported by MediaInfo) by using FFmpeg. However FFmpeg is always outputting the file as 29.97fps and I get duplicated frames from it causing bad jerkiness. From what I understand there's a soft pulldown flags in them that is being applied which is causing it duplicate frames. What's the best way to get FFmpeg to properly encode it at film speed 23.976fps and not have duplicates (just the original frames)?

[jagabo]

Field match then decimate:

-vf "fieldmatch=order=tff,decimate=cycle=5"

Field order should be detected automatically from an MPEG 2 source so shouldn't be needed. Some other sources you may need to specify tff or bff. Cycle=5 is the default so it doesn't really need to be specified in this case.