ios - Swift 3 : How to add watermark on video ? AVVideoCompositionCoreAnimationTool iOS 10 问题

Question

此代码用于在 iOS9 上为视频添加水印和文本，但自 iOS10 以来它不再起作用。有一个 iOS 10 bug已提交，但 Apple 没有答复。我无法实现任何解决方法来在视频上添加水印和文本。使用此代码有时视频会成功导出，但大多数时候不会导出。

我应该如何使用 AVVideoCompositionCoreAnimationTool 才能像在 iOS9 上那样工作。

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()
        }

    }

})

请注意:如果我删除 AVVideoCompositionCoreAnimationTool，则视频始终会导出，但是视频上没有水印和文本。如何让它工作，以便 AVVideoCompositionCoreAnimationTool 不与 AVAssetExportSession 冲突？

有些人已经实现了 workaround使用 customVideoCompositorClass 和 AVVideoCompositing 协议(protocol)，但与过去的工作方式相比，这似乎是一个繁重的解决方法。

Answer 1

这个解决方案对我有用， super 简单， super 快速

func addWatermark(inputURL: URL, outputURL: URL, handler:@escaping (_ exportSession: AVAssetExportSession?)-> Void) {
    let mixComposition = AVMutableComposition()
    let asset = AVAsset(url: inputURL)
    let videoTrack = asset.tracks(withMediaType: AVMediaType.video)[0]
    let timerange = CMTimeRangeMake(kCMTimeZero, asset.duration)

        let compositionVideoTrack:AVMutableCompositionTrack = mixComposition.addMutableTrack(withMediaType: AVMediaType.video, preferredTrackID: CMPersistentTrackID(kCMPersistentTrackID_Invalid))!

    do {
        try compositionVideoTrack.insertTimeRange(timerange, of: videoTrack, at: kCMTimeZero)
        compositionVideoTrack.preferredTransform = videoTrack.preferredTransform
    } catch {
        print(error)
    }

    let watermarkFilter = CIFilter(name: "CISourceOverCompositing")!
    let watermarkImage = CIImage(image: UIImage(named: "waterMark")!)
    let videoComposition = AVVideoComposition(asset: asset) { (filteringRequest) in
        let source = filteringRequest.sourceImage.clampedToExtent()
        watermarkFilter.setValue(source, forKey: "inputBackgroundImage")
        let transform = CGAffineTransform(translationX: filteringRequest.sourceImage.extent.width - (watermarkImage?.extent.width)! - 2, y: 0)
        watermarkFilter.setValue(watermarkImage?.transformed(by: transform), forKey: "inputImage")
        filteringRequest.finish(with: watermarkFilter.outputImage!, context: nil)
    }

    guard let exportSession = AVAssetExportSession(asset: asset, presetName: AVAssetExportPreset640x480) else {
        handler(nil)

        return
    }

    exportSession.outputURL = outputURL
    exportSession.outputFileType = AVFileType.mp4
    exportSession.shouldOptimizeForNetworkUse = true
    exportSession.videoComposition = videoComposition
    exportSession.exportAsynchronously { () -> Void in
        handler(exportSession)
    }
}

抱歉，如果我没有发布如何调用此函数。我已经有一段时间没有触及该代码了，所以我希望这就足够了:

let outputURL = NSURL.fileURL(withPath: "TempPath")
let inputURL = NSURL.fileURL(withPath: "VideoWithWatermarkPath")
addWatermark(inputURL: inputURL, outputURL: outputURL, handler: { (exportSession) in
    guard let session = exportSession else {
        // Error 
        return
    }
    switch session.status {
        case .completed:
        guard NSData(contentsOf: outputURL) != nil else {
            // Error
            return
        }

        // Now you can find the video with the watermark in the location outputURL

        default:
        // Error
    }
})