These 2 tools are free-ware and works very well for me making Thumbnail- and Picture-captures of videos.

My Thumbnail-capture-tool is "GDS Video Thumbnailer" (current version is 7.0.8), and it is Danish as I am.
You can configure it in many ways - I had to play around with it, before I found my preferable settings - the default settings I could not use.
A bonus: If you check a settings, it also extract the pictures in the same same as in the movie.

Link to the site, where it can be downloaded (site is in English and the app too): hxxps://www.gdsoftware.dk/more/3/page~software (please substitute xx with tt)


My Picture-capture-tool is "ImageGrab" (current version is 7.0.4).
You can also configure this in many way - I had to play around with it, before I got to know how to use it, but then...
You can capture each frame (or picture) from a movie, if you want to.

Link to the site, where it can be downloaded: hxxps://paulglagla.com/en/imagegrab-2/ (please substitute xx with tt)


Both sites are trustworthy - please believe me, I am an IT professionel.