Hi,
Taking screen shots when a hot key is pressed like F12, wont be an issue, but getting the text from the image, that is subtitle may not be 100% accurate.
I have done my masters in computer science and am working as a senior software engineer for a local company in Bahrain, where most of out clients are banks.
I can work on the needed for you, and show you demo, once you are okay with result we can continue and finalize the project.
Thanks