CarGuo/GSYVideoPlayer ? reverse-engineered prompt

Build me an Android video player app using this project’s library that shows off the main playback features in a clean demo experience.

I want a simple home screen with a list of sample videos, then a player screen where I can play, pause, seek, switch quality, go full screen, and adjust volume and brightness by dragging. It should support external subtitles, bullet chat over the video, screenshots or GIF capture, and a few basic visual effects like filters and watermarks. Please include caching while playing, support for different playback engines, and make sure it handles HTTPS and common streaming formats smoothly.

If it makes sense, add a picture in picture or small window mode, and let multiple videos play at once in a demo section. Keep the UI polished and easy to understand. Use the existing project structure, and look up current docs online if you need to.