Hi there,
I captured this PAL VHS tape with my Panasonic NV-FS200 through a DataVideo TBC-3000 into an ATI600 USB card in VirtualDub2 FFV1 format. Here are two consecutive frames with their fields separated:
franklyjazz[PANA-TBC3000].00.jpg
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As you can see the fields appear to be misaligned: Field B of the first frame should be in the second frame, and its Field B should be in the consecutive frame etc.
Furthermore the Field B of the first frame is the same as Field A of the second frame: it captures the same instant in time. But the quality is different. Frame1FieldB has some dizzy lines running vertically through the picture, while Frame2FieldA is smooth. (compare the edges!)
The obvious solution would be to just skip all the B fields, and de-interlace from Field A to a full frame. But I'm wondering how it came to be like this, and if maybe there's a better solution.
...some info on the lineage: the VHS cassette contained all material from U.S. origin. The fragment in question is from an episode from a sixties U.S. jazz show, called Frankly Jazz. The episodes from this program were originally recorded on 2-inch videotape masters (although I saw a claim of them being kinescoped), and somehow a copy ended up on a PAL VHS cassette in Belgium. I can't imagine someone making a PAL copy of the original videotape in the U.S.A., so probably the lineage is through some intermediary NTSC videotape format onto this PAL cassette.
Thanks
Karel
