how to tell up field first or down field first

[george_zhu]

I captured 480x480 interlaced video with Virtual VCR from a Hi8 camcorder. How can I tell whether it is up field first or down field first?

[sprit]

I use avisynth and virtualdub, like this:
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Create scriptAVISource("file.avi").AssumeTFF().SeparateFields() Open script i VD
Step forward frame by frame; if moving parts "jerks" (you'll know what I mean when you see it), then the video is BFF, otherwise it is TFF.
(optional, an extra check) Change 'AssumeTTF()' to 'AssumeBFF()' and try the clip that way
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(I assume "up field first" is top field first, and "down field first" is bottom field first.)