How to use UIVideoEditorController to edit alAsset without copying to app directory?

Question

I am trying to use UIVideoEditorController to allow users to select and trim videos from the photos library.

UIVideoEditorController requires files to be present in the app directory and cannot load alAssets directly. Since videos could be large and copying them would take a lot of time are there any other ways to accomplish this?. In more detail -

1. Can UIVideoEditorController trim videos directly from the photos library without copying?

2. Are there any alternatives to UIVideoEditorController apart from implementing my own controller using AVFoundation(Which is quite a task..)