Force AVI recording to start aligned to odd/even frames

[LocalH]

I have developed a method of capturing video from WinUAE at normal height, and weaving it into an interlaced video to produce a video suitable for burning on a DVD. However, due to the fact that I don't start recording until the machine has already booted to a CLI (in the case of CLI-started demos), it's impossible to know whether I started recording on an odd or even frame (and thus how I need to accurately discern the field affinity for my interim MJPEG AVI). Case in point - I've recorded several demos with no visual problems, but one (Lemon.exe) looks perfect in Bob up until the end picture, which is in interlace mode. In either Bob or Weave (to a lesser extent in Bob), I detected that the fields seem physically swapped, which I confirmed by swapping the fields in DScaler's input properties. As it would be nice to have a single streamlined process that can be used to make perfect videos suitable for playback on a real TV/video monitor, I would like to request the capability to force the recording to start on either an odd or an even frame (can be represented merely by a single bit that flips once per frame). Then, with this switch enabled, all videos would have the same field affinity when weaved together.