Thanks guys.
Development work : I affirm that I am willing to do any/all development work for this project, especially given the nature of what I want to do.
I am investigating the possibility of misusing (repurposing?) calibre as a front end to my fairly extensive video library. I currently use a WD TV Live box which plays files directly from my NAS. The upside of this is that I don't need to have a PC running. The downside is that I can either use the media library functions on the WD box or simply browse a list of titles. The title list is much faster and more convenient ... until I forget the name. I have set up hard links on the NAS to provide some primitive indexing via lead actor, director, genre, series but it is soul destroying to do this manually. Unfortunately WD have given no indication of upgrading the TV Live to support the more recent video formats (10 bit colour, HEVC and the like) nor do they appear to have any successor products. My plan is to use a small linux computer (intel NUC or even a Raspberry Pi) running calibre and vlc, with the actual calibre library on the NAS. This leaves me with two problems - adding the video files to the library and populating a set of custom columns with director, cast, genre and similar info. If I can add custom "book" types (.mkv, .mp4, .avi etc) then I can use the calibre GUI bulk add to get the actual files into the library, after which I can use a python script to parse my DVD Profiler database and the calibre command line to insert the additional information. As you say, I can parse the file source tree myself but why write code if it is already there and tested
I'm willing to write an import plugin if I have to. There will be no file conversion issues for obvious reasons but in fact it would be useful to take control of the file copy operation so that I can keep my existing master library and use links for the calibre library instead of doing a straight copy. The pointer to the KePub plugin may make life a lot easier.
TBH, in many ways it would be easier to start with DVD Profiler as the front end but there is no natural way to play a film from within DVD Profiler (it expects them to be on disks) plus there is no native linux version and I can't be asked to write plugins for windows code running under wine. Besides, the typing, sorting, series identification etc is much better under calibre.
If this works I will make any plugins and scripts available to anyone who wants them, although I suspect they will need tailoring as this is not intended as a fully general utility, just a one-shot conversion.
Just to confirm, .nef was an example, I should have realised that almost all the three letter extensions are already taken.