Which one should I pick for a new project?

I can only help you understand the specifics of carguo/gsyvideoplayer or facebookarchive/rebound themselves—I can't recommend which to use for your project, as that depends on your requirements, which you haven't described.

However, I can clarify what each repository does:

[carguo/gsyvideoplayer] is a video player library for Android. It supports multiple playback engines (IJKPlayer, ExoPlayer, MediaPlayer, AliPlayer), offers advanced features like caching, filters, danmaku (bullet chat), subtitles, ads, and multiple simultaneous playback. Use it if you need to play video in an Android app.

[facebookarchive/rebound] is a spring physics animation library for Android. It provides spring-based animations for UI interactions (scaling, scrolling, gallery effects). Use it if you need fluid, physics-driven animations. Note: it's archived, meaning Facebook no longer maintains it.

To pick correctly, ask yourself:

• Do I need video playback? → gsyvideoplayer
• Do I need spring-physics animations? → rebound (with the caveat that it's archived/unmaintained)

If you have a specific use case in mind, I can help explain how either library works in detail.

FOLLOW_UPS:

• What video playback features does gsyvideoplayer provide?
• Why is rebound archived and what's the status?
• How do I integrate gsyvideoplayer into my app?