I notice a black line on the very bottom edge of the frame on some SD uncompressed QT files from archival sources.
The files are made from Betacam or pre-Betacam sources and some from 16mm. The black line is 2 or 3 pixels high so would disappear on the old cathode ray tube but now that I am up-converting these files to HD 108060i through a Kona card, the lines become more apparent. This will require me to scale or crop slightly after the fact.
Any ideas where that line comes from? I guess that in some cases the original material was 640 x 480 not 720 by 486 but what about the film transfers? Is this a common problem?