Capture a screenshot from mov video types

#import <AVFoundation/AVFoundation.h>

AVAssetImageGenerator *imageGenerator = [[AVAssetImageGenerator alloc] initWithAsset:self];
CMTime duration = self.duration;
CGFloat durationInSeconds = duration.value / duration.timescale;
CMTime time = CMTimeMakeWithSeconds(durationInSeconds * 0.5, (int)duration.value);
CGImageRef imageRef = [imageGenerator copyCGImageAtTime:time actualTime:NULL error:NULL];
UIImage *screenshot = [UIImage imageWithCGImage:imageRef];
CGImageRelease(imageRef);