Crop video with AVFoundation

Question

I try to crop a video in square with AVFoundation which I follow the tutorial from this web site http://www.netwalk.be/article/record-square-video-ios.

My question is how to crop a square video with an area that I selected (like when you select a photo in UIImagePicker or like in instagram). The example gives me a square video but cropping from the center.

Thank you for your advice.

Answer 1

Notice in the // rotate to portrait portion of the code they're making affine transformations. Modify those transformations to align the video how you want.