Using external application (or library) as calibre plugin
1st - I'm sorry for bothering you, but I'm rather fresh user of calibre and it's plugins.
I need to run external application, transfer filename to it, perform some action and transfer results back to calibre. I'm not familiar with python, but I read source of Open With plugin and realised how to do first 2 steps (open, transfer filename as argument). But I'm stack with the last one. I have some programs written by me and I'd like to use it as extension for Calibre (I'm fresh green in python and i'ts too complicated to rewrite it for me). Programs give result inline, but it's no problem for me to add other way for communication (f.e. as export function in dll). Which way will be the best and simplest for calibre? How shoud look adequate fragment of py code? Or which other plugin has such functionality?
Can anyone help me, please?
Thanks for your help, regards.