Thanks, that was a comprehensive reply which got me thinking.
These are mostly home videos, currently transferred to DVD to play on a DVD player, and some from the camera phone.
The ideal scenario is to convert them to the current format in vogue. So, for example, I have an Android device, and a PC, and a Mac. I'm not overly concerned about archiving right now as the DVD is the current archive. Although, I know, that too will have a finite life. At least, for now, the files are relatively stable on DVD in digital format.
I want to make it easy to output the desired format for the OS and screen size.
I am not a professional, it's primarily for home use, however, I can see where production of effective video files would make distribution easier.
I wanted to try a video conversion program, and found a whole host of them packed with unwanted baggage. I'm happy to pay for the software, but it needs to be reasonably lightweight (not bloatware) as i have non-commercial requirements.