Videos and images generating correct featured images


I would like to have just a single field to use it to post URLs only. Video URLs, IMG URLs and links. I don't need uploads. Just the good old copy/paste to insert videos and images and links.

The problem is I can make the featured images to be delivered the right way. I have the option to use the first image as the featured one which works fine for image posts but not for videos (the plugin grabs the img from the previous post). I already tried to use another plugin to grab video poster frame's as the feature (video thumbnails PRO) but I this case I can no longer check the option "use first img as featured".

How can I have the correct featured images for both video and images URS?

Thank you