digitized eight old #VHS tapes, first two with `ffmpeg -vf bwdif` (deinterlacing filter, with default options).
turns out this did the wrong thing (motion was juddery, something like frame order 2 1 4 3 6 5 instead of 1 2 3 4 5 6), but a simple frame swapping program I wrote to fix it made some parts perfect but other parts even worse (swappting wrong pairs like ... 4 1 6 3 8 5 ...), so I think #ffmpeg #bwdif does some autodetection/switching during the video encoding.
can not redigitize the first tape because VCR machine chewed it.... workaround until I figure out a proper solution: drop half the frames to give a 25fps output video instead of 50fps.
second tape I redigitised, like the other six tapes, using `-vf bwdif=parity=bff` which seems to be the correct #interlacing #FieldOrder for my capture hardware and source (EasyCAP USB device with JVC #VCR , norm #PAL , 720x576i50), at least I haven't spotted juddery motion there.
