How do I maintain interlace video ?

I have an interlaced project I need to export using Mpeg-4 file format and H264 compression.

I have tried all the codecs in compressor 4 and FCPX changes to progressive.

What do I need to do to maintain interlaced video ?

Thanks.

Interesting, why do you need interlaced for H.264?

H.264 does in some instances support interlaced video. Bear in mind that "H.264" is actually a family of codec specs, not just one codec.

I've never been asked about this issue, never had a personal need (all of our work in our studio is progressive), and will run some tests today and post back.

But, to start with, what are the specific settings for your project?

Double check your project settings. I just ran a test, and exporting Master File as H.264 gave me interlaced video.