AVFoundation 框架提供了 AVMutableVideoComposition 类(AVVideoComposition 的可变变体)。看起来您可以将 CoreAnimations 直接渲染到此类的实例以创建视频,但我不知道如何将合成保存到文件或如何使用它,真的。从 UIViewController 调用的以下代码似乎可用于创建合成和动画,但是,我对如何使用合成感到困惑。非常感谢任何帮助或指导。
static AVMutableVideoComposition *videoComposition = nil;
- (void)animationDidStop:(CAAnimation *)animation finished:(BOOL)flag {
//Do something with videoComposition here... how to save it to a file?
NSLog(@"videoComposition: %@", videoComposition);
[videoComposition release]; videoComposition = nil;
}
- (IBAction)createVideoComposition:(id)sender {
AVVideoCompositionCoreAnimationTool *videoCompositionCoreAnimationTool = [AVVideoCompositionCoreAnimationTool videoCompositionCoreAnimationToolWithPostProcessingAsVideoLayer:self.view.layer inLayer:self.view.layer];
videoComposition = [[AVMutableVideoComposition videoComposition] retain];
[videoComposition setRenderSize:CGSizeMake(320.0, 480.0)];
[videoComposition setRenderScale:1.0];
[videoComposition setFrameDuration:CMTimeMake(1, 10)];
[videoComposition setAnimationTool:videoCompositionCoreAnimationTool];
//add a basic animation to shake the controller's view
CAKeyframeAnimation *shakeAnimation = [CAKeyframeAnimation animationWithKeyPath:@"position"];
shakeAnimation.delegate = self;
shakeAnimation.removedOnCompletion = YES;
shakeAnimation.duration = 0.5;
CGMutablePathRef path = CGPathCreateMutable();
CGFloat midX = self.view.center.x;
CGFloat midY = self.view.center.y;
CGPathMoveToPoint(path, nil, midX, midY);
CGPathAddLineToPoint(path, nil, midX + 10.0, midY);
CGPathAddLineToPoint(path, nil, midX - 20.0, midY);
CGPathAddLineToPoint(path, nil, midX + 15.0, midY);
CGPathAddLineToPoint(path, nil, midX - 5.0, midY);
CGPathAddLineToPoint(path, nil, midX, midY);
shakeAnimation.path = path;
CFRelease(path);
[self.view.layer addAnimation:shakeAnimation forKey:@"shakeAnimation"];
}
谢谢,乔恩