How to access the video recorded using Replaykit as a file and merge another video to it?

Question

How to access the video recorded using Replaykit as a file and merge another video to it ?

Answer 1

With iOS 11, you can have direct access to the video. See https://developer.apple.com/videos/play/wwdc2017/606/

You can save it using AVAssetWriter, then do whatever you want with it after that.