I’m wrapping up a little trio of edits which involve bringing together existing footage from a variety of not-exactly-optimal sources (odd MPEG1 files, WMVs, some DV, all 4:3) with some professionally shot 720p footage. Thank goodness for FCP’s multi-format timeline (and MPEGstreamClip for converting virtually anything into anything else).

Of course, I’ve been editing 720p pretty much exclusively for months now, so when some DV footage needed to be inserted, I faced… Cue dramatic chord: The Curse of the Mouse Teeth From Hell.

I guess that if you’ve only ever edited DV footage, especially if you edit your own material, you’ll just shrug your shoulders and wonder what I’m on about. But if you’ve ever dropped in a bit of NTSC into a PAL timeline, or scaled up some DV, you’ll have seen those unsightly blocky edges that suddenly appear around anything that moves. As if some monster rat has been nibbling away at your video.

We’re not talking that blocky pixels from overworked compression or a bad tape dropout, we’re talking bobbly edges on things that move fast in frame. It’s caused by the interlaced video being stretched in a non standard way. For example, NTSC being stretched from 720×480 to 720×576, or PAL being stretched up from 720×576 to 1280×720. The on-off-on-off cadence goes to pot, and the fields are chosen in a ‘knit 3, pearl 7’ way, and you get… video that’s been attacked by monster-mice when anything moves.

Well, all this rodentry is only mentioned because I found a quick and dirty fix. Whilst not exactly perfect, it doesn’t rely on a quarter of a million quid’s worth of Snell & Wilcox Alchemist either.

Get the properties of your upscaled and interlaced footage, and set the clip’s properties to a field dominance of none. It gets scaled progressively, gaining some softness and quasi motion-blur at the expense of the crisp video like motion.