在iOS中将视频裁剪成圆圈？

Question

I am trying to crop a video, that has been taken with an iPhone camera and then place it on top of a UIImageView. I have been following this SO Question How to crop a video to a circle in iOS?. And I can now take the video and put it on top of another perviously recorded video. Now I want to have the background be a image and the foreground be the cropped video. My main issue right now is getting video cropped in the part I want cropped. I cannot post all the code here but here is where the github repo is and the class that does the modifying is called CustomVideoCompositor.m https://github.com/mayoff/stackoverflow-28258270-video-in-oval-on-video/tree/master/video . And I am having trouble editing it into the circle I want I want it to be a oval that is in the bottom half and higher than wider.

EDIT

I want to make the cut so that only things in this part of the rounded rectangle would be cropped and available.

Answer 1

You'll need to use AVPlayer as this enables you to play several videos back at once or have your video appear on top of another view. Also, by using AVPlayer and an AVPlayerLayer its easy to then make the video appear circular. (Here's a good tutorial on it to learn more: http://jacopretorius.net/2013/02/playing-video-in-ios.html )

Here's the code (for Objective-C):

In your view controller .h file:

#import <AVFoundation/AVFoundation.h>

Then in viewDidLoad :

[super viewDidLoad];

// Set up the image view first (the imageView is an IBOutlet)
self.imageView.image = [UIImage imageNamed:@"image"];
self.imageView.alpha = 0.2;

NSURL *url = [[NSBundle mainBundle] URLForResource:@"video" withExtension:@"mp4"];
AVPlayer *player = [AVPlayer playerWithURL:url];

CGFloat diameter = MIN(self.view.frame.size.width, self.view.frame.size.height) * 0.8;

AVPlayerLayer *layer = [AVPlayerLayer playerLayerWithPlayer:player];
layer.videoGravity = AVLayerVideoGravityResizeAspectFill;
layer.frame = CGRectMake((self.view.frame.size.width - diameter) / 2,
                         (self.view.frame.size.height - diameter) / 2,
                         diameter, diameter);

layer.cornerRadius = diameter / 2;
layer.masksToBounds = YES;

// Put the AVPlayerLayer on top of the image view.
[self.view.layer addSublayer:layer];

[player play];

Answer 2

If you want only a visual effect of cropped video, without modification of video file, you can simply add a mask to your video layer. I mean CALayer mask property.

You can create circle mask like this: draw black rectangle, then draw transparent circle on it.