Best program for syncing video and audio

First time here.
I'm doing a bit of research on whether there is a program to do such thing because I want to do a program that syncs audio and video and therefore I'm checking whether it has already been done.

What am I looking for is given video and audio that is of the video but there is a noticeable offset, the program can return the number of milliseconds, or frames or whatever units that is the audio and video off.

What I am not looking for is for given audio-video file and audio file, return offset. Because that is audio-audio syncing. I'm looking only for audio-video syncing. Audio-audio syncing has been done and tutorials for how to do it is the only thing I can find when searching for audio-video syncing.

Everything like converting input and such and the format of the output and that is of no worries. Format conversion can be done for sure.

My program is supposed to return synced audio-video given unsynced audio and video files. For that, I will be looking into neural networks and hopefully bits of Python code and using already made tools, like Lip detection.

So the information I would like to get is whether there are really no programs that can do such a thing or if there are similar ones. If there are, where can I find them and their description?