You need to record your video on to your computer, then you should be able to grab stills, not sure what software/hardware you will need suggest you search for archive video on google or similar.
Stewart
TZD 19 TD one of the few
Xantia Td estate, going soft
You can get TV-cards for your computer which allow you to use your pc as a TV but also usually allow you to capture reasonable quality still images from the video. Look on eBay for things like Win TV or PCI TV card or USB TV. You can get them really cheaply nowadays.
David
BX19TRS 118K E Reg 1992-2008
BX19TRS auto abs 96k F Reg
BX19TXD 150k K Reg