I run a 4chan style imageboard. When users post youtube or soundcloud links, I would like for the board to give a second link which, when clicked, would embed the video.
If I am not mistaken, 4chan uses JS to accomplish this. I have also seen many forum admins using php to do this. I know that wordpress uses php to do this.
If I went with php, I was thinking of going with something based on this: https://www.warpconduit.net/2013/04/13/automatically-embedding-video-using-only-the-url-with-the-help-of-oembed/
For JS I am not entirely sure how to go about it. I would probably use a regex to detect youtube urls and then convert that information to an embed