在我的应用程序中,我修复了1280 x 720的构图渲染大小.因此,如果将导入任何肖像视频,那么我必须在中心显示视频的填充和aspect框架的模糊背景.像这样：
https://www.youtube.com/watch?v=yCOrqUA0ws4
我实现了使用AVMtableComposition播放两个视频,但我不知道如何模糊一个特定的背景轨道.我在代码中执行了以下操作：
self.composition = [AVMutableComposition composition]; AVAsset *firstAsset = [AVAsset assetWithURL:[NSURL fileURLWithPath:[[NSBundle mainBundle] pathForResource:@"ScreenFlow_Blend" ofType:@"mp4"]]]; [self addAsset:firstAsset toComposition:self.composition withTrackID:1]; [self addAsset:firstAsset toComposition:self.composition withTrackID:2]; // [self addAsset:ThirdAsset toComposition:self.composition withTrackID:3]; AVAssetTrack *backVideoTrack = [firstAsset tracksWithMediaType:AVMediaTypeVideo][0];; self.videoComposition = [AVMutableVideoComposition videoComposition]; self.videoComposition.renderSize = CGSizeMake(1280,720); self.videoComposition.frameDuration = CMTimeMake(1,30); AVMutableVideoCompositionInstruction *instruction = [AVMutableVideoCompositionInstruction videoCompositionInstruction]; instruction.timeRange = [backVideoTrack timeRange]; CGFloat scale = 1280/backVideoTrack.naturalSize.width; CGAffineTransform t = CGAffineTransformMakeScale(scale,scale); t = CGAffineTransformTranslate(t,-backVideoTrack.naturalSize.height/2 + self.videoComposition.renderSize.height/2); AVMutableVideoCompositionLayerInstruction *frontLayerInstruction = [AVMutableVideoCompositionLayerInstruction videoCompositionLayerInstruction]; frontLayerInstruction.trackID = 1; [frontLayerInstruction setTransform:t atTime:kCMTimeZero]; CGFloat scaleSmall = 720/backVideoTrack.naturalSize.height; CGAffineTransform translate = CGAffineTransformMakeTranslation(self.videoComposition.renderSize.width/2 - ((backVideoTrack.naturalSize.width/2)*scaleSmall),0); CGAffineTransform scaleTransform = CGAffineTransformMakeScale(scaleSmall,scaleSmall); CGAffineTransform finalTransform = CGAffineTransformConcat(scaleTransform,translate); CGAffineTransform t1 = CGAffineTransformMakeScale(scaleSmall,scaleSmall); t1 = CGAffineTransformTranslate(t1,1280,0); AVMutableVideoCompositionLayerInstruction *backLayerInstruction = [AVMutableVideoCompositionLayerInstruction videoCompositionLayerInstruction]; backLayerInstruction.trackID = 2; [backLayerInstruction setTransform:finalTransform atTime:kCMTimeZero]; // AVMutableVideoCompositionLayerInstruction *maskLayerInstruction = [AVMutableVideoCompositionLayerInstruction videoCompositionLayerInstruction]; // maskLayerInstruction.trackID = 3; // [maskLayerInstruction setTransform:t atTime:kCMTimeZero]; instruction.layerInstructions = @[backLayerInstruction,frontLayerInstruction]; self.videoComposition.instructions = @[ instruction ]; AVPlayerItem *playerItem = [AVPlayerItem playerItemWithAsset:self.composition]; playerItem.videoComposition = self.videoComposition; self.player = [AVPlayer playerWithPlayerItem:playerItem]; AVPlayerLayer *newPlayerLayer = [AVPlayerLayer playerLayerWithPlayer:[self player]]; [newPlayerLayer setFrame:[[[self playerView] layer] bounds]]; // [newPlayerLayer setHidden:YES]; [[[self playerView] layer] addSublayer:newPlayerLayer]; [self setPlayerLayer:newPlayerLayer];
使用上面的代码我可以实现这一点：
https://drive.google.com/open?id=0B2jCvCt5fosyOVNOcGZ1MU1laEU
我了解customVideoCompositor类来过滤组合框架.我尝试了,但如果我使用customVideoCompositor然后我失去了在组合层的转换.另外,从customVideoCompositor我不知道如何过滤特定的跟踪ID.
解决方法
在添加屏幕中心的第二个视频层之前,添加此代码
UIVisualEffect *blurEffect; blurEffect = [UIBlurEffect effectWithStyle:UIBlurEffectStyleExtraLight];//Change the effect which you want. UIVisualEffectView *visualEffectView; visualEffectView = [[UIVisualEffectView alloc] initWithEffect:blurEffect]; visualEffectView.frame = self.view.bounds; [self.view addSubview:visualEffectView];
在斯威夫特
let blurEffect = UIBlurEffect(style: UIBlurEffectStyle.Light) //Change the style which suites you
let blurEffectView = UIVisualEffectView(effect: blurEffect)
blurEffectView.frame = view.bounds
blurEffectView.autoresizingMask = [.FlexibleWidth,.FlexibleHeight] // for supporting device rotation
view.addSubview(blurEffectView)
