Surging after deinterlace

[Jason J. Gullickson]

I wasn't sure if this belonged here or in one of the editing areas, but I'm sure it will get moved if I guessed wrong...

We're in the process of "remastering" our short films so we can release high(er) quality versions on the web. All of these films were shot on DV at 30/60i, edited with Final Cut Express and now exist as "uncompressed" (meaning, not converted when exported from FCE) quicktime files.

My first mission in cleaning these up is to get rid of the "interlace artifacts", the breaking up of objects moving horizontally in the frame. I've been working with the JES deinterlacer and I'm loving the results for the most part, but I'm noticing something weird and I want to know why it's happening and if it can be corrected.

After deinterlacing, I notice that objects "surge" as they move across the screen occasionally. The easiest place to see this is on one of the clips where a car drives across the screen from right to left; as it crosses the frame, it almost looks like it "speeds up" for a couple of frames as it crosses the frame and then as it exits on the left. This may be happening elsewhere, but it's most noticeable here.

I've seen this before even when JES is not involved and I'm wondering if it's something in the nature of the deinterlacing process, or something I'm doing wrong. Maybe it's just a playback problem and I'm just imagining it?

I plan on doing some more experiments with various settings in JES and also taking this output and playing it back on other progressive displays (since ultimately, I want it to play back well on the computer screen), but I thought I would pose the question here to see if there is something obvious that I'm doing wrong, or some way I can work around it.

Thanks!