Hi

I have noticed a couple of times that compressing a QT reference movie (XDCAM EX 1080/25p) to a m2v using the DVD Best Quality 90 minute preset, the output image appears to 'jump' a couple of times per second. The image briefly goes fuzzy. If I use the single pass preset, all is fine. I wondered if it is something to do with progressive input and output, and the jumps may be 1 per GOP, or this could be coincidence. Has anyone else seen this?

Also, if I am converting from progressive to interlace, should I use top or bottom field first?

Thanks, Nick