9
此代碼用於在iOS9上工作，爲視頻添加水印和文字，但自iOS10以後它不再工作。有一個iOS 10 bug已經提交，但沒有回答蘋果。我無法實施任何解決方法，以在視頻上添加水印和文字。有了這段代碼，視頻將被成功導出，但大部分時間不會被導出。Swift 3：如何在視頻上添加水印？ AVVideoCompositionCoreAnimationTool iOS 10問題
我應該如何使用AVVideoCompositionCoreAnimationTool，以便它可以像在iOS9上一樣工作。
let videoComposition: AVMutableVideoComposition = AVMutableVideoComposition()
videoComposition.frameDuration = CMTimeMake(1, 60)
videoComposition.renderSize = CGSize(width: clipVideoTrack.naturalSize.height, height: clipVideoTrack.naturalSize.height)
let instruction: AVMutableVideoCompositionInstruction = AVMutableVideoCompositionInstruction()
instruction.timeRange = CMTimeRangeMake(kCMTimeZero, CMTimeMakeWithSeconds(60, 30))
// transformer is applied to set the video in portrait otherwise it is rotated by 90 degrees
let transformer: AVMutableVideoCompositionLayerInstruction =
AVMutableVideoCompositionLayerInstruction(assetTrack: clipVideoTrack)
let t1: CGAffineTransform = CGAffineTransform(translationX: clipVideoTrack.naturalSize.height, y: -(clipVideoTrack.naturalSize.width - clipVideoTrack.naturalSize.height)/2)
let t2: CGAffineTransform = t1.rotated(by: CGFloat(M_PI_2))
var finalTransform: CGAffineTransform = t2
transformer.setTransform(finalTransform, at: kCMTimeZero)
instruction.layerInstructions = NSArray(object: transformer) as! [AVVideoCompositionLayerInstruction]
videoComposition.instructions = NSArray(object: instruction) as! [AVVideoCompositionInstructionProtocol]
let mixComposition = AVMutableComposition()
let compositionVideoTrack = mixComposition.addMutableTrack(withMediaType: AVMediaTypeVideo, preferredTrackID: kCMPersistentTrackID_Invalid)
do {
try compositionVideoTrack.insertTimeRange(CMTimeRangeMake(kCMTimeZero, asset.duration), of: clipVideoTrack, at: kCMTimeZero)
} catch {
print(error)
}
//Add watermark
let myImage = UIImage(named: "logo")
let aLayer = CALayer()
aLayer.contents = myImage!.cgImage
aLayer.frame = CGRect(x: (clipVideoTrack.naturalSize.height*(self.view.bounds.width-45))/self.view.bounds.width, y: (clipVideoTrack.naturalSize.height*(self.view.bounds.width-40))/self.view.bounds.width, width: (clipVideoTrack.naturalSize.height*40)/self.view.bounds.width, height: (clipVideoTrack.naturalSize.height*40)/self.view.bounds.width)
let titleLayer = CATextLayer()
titleLayer.string = "text"
titleLayer.font = UIFont(name: "helvetica", size: 0)
titleLayer.fontSize = clipVideoTrack.naturalSize.height/16
titleLayer.shadowOpacity = 0.5
titleLayer.alignmentMode = kCAAlignmentCenter
titleLayer.frame = CGRect(x: 0, y: 0, width: clipVideoTrack.naturalSize.height, height: clipVideoTrack.naturalSize.height/6)
titleLayer.display()
let videoSize = asset.tracks(withMediaType: AVMediaTypeVideo)[0].naturalSize
let parentLayer = CALayer()
let videoLayer = CALayer()
parentLayer.frame = CGRect(x: 0, y: 0, width: videoSize.height, height: videoSize.height)
videoLayer.frame = CGRect(x: 0, y: 0, width: videoSize.height, height: videoSize.height)
parentLayer.addSublayer(videoLayer)
parentLayer.addSublayer(aLayer)
parentLayer.addSublayer(titleLayer)
videoComposition.animationTool = AVVideoCompositionCoreAnimationTool(postProcessingAsVideoLayer: videoLayer, in: parentLayer)
do { try FileManager.default.removeItem(at: filePath) }
catch let error as NSError {
NSLog("\(error), \(error.localizedDescription)")
}
var exportUrl: URL = filePath
self.videoUrl = filePath as NSURL
var exporter = AVAssetExportSession(asset: asset, presetName: AVAssetExportPresetMediumQuality)
exporter!.videoComposition = videoComposition
exporter!.outputFileType = AVFileTypeQuickTimeMovie
exporter!.outputURL = URL(fileURLWithPath: exportUrl.path)
exporter!.exportAsynchronously(completionHandler: {
DispatchQueue.main.async {
self.view.layer.addSublayer(self.avPlayerLayer)
let item = AVPlayerItem(url: exportUrl)
self.player.replaceCurrentItem(with: item)
if (self.player.currentItem != nil) {
print("Starting playback!")
self.player.play()
}
}
})
請注意：如果我刪除AVVideoCompositionCoreAnimationTool那麼視頻始終是出口，但對此，漢斯無水印和視頻文本。如何使其工作，使AVVideoCompositionCoreAnimationTool不與AVAssetExportSession衝突？
一些實施workaround與customVideoCompositorClass和AVVideoCompositing協議，但這似乎是一個繁重的解決方法相比，它如何工作。