I have created such a tool for my own users. There are two types of code that can be supplied, an embed or an object. The code copied from that other website will not run in older Internet Explorer because it lacks embed. But neither version will run on an Apple mobile device. There is a slightly smaller code that will run on Apple mobile and other newer browsers, but it will not run in older Internet explorer and opera. You will have to choose (drop older browsers or drop Apple mobile).
My code will provide an input box, output code, and output video, and will not copy code from another web site. It will be a self-contained module of code that can be inserted within your existing page, which you can style as needed. If you need it integrated with your content or stylesheet, that will be extra.