lipangit/JiaoZiVideoPlayer ? reverse-engineered prompt

Build me an Android video player library that’s easy to drop into an app and customize. I want it to handle common playback well, with a nice full screen experience, controls the user would expect, and enough flexibility that I can change the look and behavior without fighting the code. Please include a simple demo app that shows how to use it in a few different ways, so I can test it quickly and see the main features working.

If it makes sense, support different playback backends and keep the code organized so it can grow into a reusable video framework instead of just a one off player. Make the default experience polished, but keep it simple enough that someone can understand how to use it from the sample. If you need to check current docs or best practices online while building it, go ahead.