you can definitely do it with ffmpeg, which you should already have since it's required by the Videos component. You'd have to run ffmpeg as a command like it's shown in the stack overflow post that Z-Man linked. You could either do this at the time of upload by editing the Videos component, or you could write a cron job to do it for, say, all videos uploaded in the past 24 hours and only run it once a day.

Since the Video component is using ffmpeg for creating the final video file, you may run ffmpeg again at the end of the convert method in order to add a still image with your logo in the beginning. See
https://stackoverflow.com/questions/24102336/how-can-i-place-a-still-image-before-the-first-frame-of-a-video

My website is a social media so I want to know what file in the video component to edit to automatically add a logo. I have a porn script and I have to edit the video include file so I want to know do I edit the main ossn file or do I go in plug-in and edit the view file

I think I get what your saying. To put a logo on any video you will need Wondershare Filmora or something similar. I use it for youtube, vimeo and my own videos. Hope this helps.

Yes or even a logo so I was wonder what file I should edit

Do you mean by watermark ?

No I bought the video component and want to add a logo to it

No idea which video file you mean? did you wrote your own video component? are you talking about youtube videos?