[nickr]

Have you looked at the JSON-RPC hooks?

[DaveBlake]

But on another hand I used sublime to do little exploring in the code and found  AVFrame* CFFmpegImage::ExtractFrame()   I am going to assume that this is the function that actually extracts the thumbnails from videos,
Now if only I can figure out how it is being called more so how to send the url to it from python and cause it to run on my terms.

I mean this as kindly and politely as I can, but I think you will need to do a lot more investigation and a lot less assuming.

Does anyone know off the top of there heads how or at what point python addons hooks back into c++, so maybe I can trace one of the python function back into c++ to get a guide for adding this?

Python scripts use JSON API as Nick says, there is alo a legacy interface of calls. I guess start reading about addon development since Python seems to be your interest area (not core development) https://kodi.wiki/view/Python_development

But give up on the idea that you will be able to add a quick hook from Python to to C++ to achieve what you want or expose core functionality. You need to learn more about Kodi and then you will see why that is the case. Sorry, but I'm not going to be able to explain in a few lines here.