отаю надVideo на основе приложения вSwift3, Согласно моему требованию, я должен слитьVideo а такжеAudio AVAsset в один, отрегулируйте их громкость отдельно и сохраните финалVideo вiPhone Device gallery, Это работает нормально, используя следующий код:

func mergeVideoAndMusicWithVolume(assetVideo: AVAsset, assetMusic: AVAsset, startAudioTime: Float64, volumeVideo: Float, volumeAudio: Float){

        //To merging a video and a music and set it a volume
        let dirPaths = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)
        let docsDir = dirPaths[0] as String

        let composition: AVMutableComposition = AVMutableComposition()
        let compositionVideo: AVMutableCompositionTrack = composition.addMutableTrack(withMediaType: AVMediaTypeVideo, preferredTrackID: CMPersistentTrackID())
        let compositionAudioVideo: AVMutableCompositionTrack = composition.addMutableTrack(withMediaType: AVMediaTypeAudio, preferredTrackID: CMPersistentTrackID())
        let compositionAudioMusic: AVMutableCompositionTrack = composition.addMutableTrack(withMediaType: AVMediaTypeAudio, preferredTrackID: CMPersistentTrackID())

        //Add video to the final record
        do {
            try compositionVideo.insertTimeRange(CMTimeRangeMake(kCMTimeZero, assetVideo.duration), of: assetVideo.tracks(withMediaType: AVMediaTypeVideo)[0], at: kCMTimeZero)
        } catch _ {
        }

        //Extract audio from the video and the music
        let audioMix: AVMutableAudioMix = AVMutableAudioMix()
        var audioMixParam: [AVMutableAudioMixInputParameters] = []

        let assetVideoTrack: AVAssetTrack = assetVideo.tracks(withMediaType: AVMediaTypeAudio)[0]
        let assetMusicTrack: AVAssetTrack = assetMusic.tracks(withMediaType: AVMediaTypeAudio)[0]

        let videoParam: AVMutableAudioMixInputParameters = AVMutableAudioMixInputParameters(track: assetVideoTrack)
        videoParam.trackID = compositionAudioVideo.trackID

        let musicParam: AVMutableAudioMixInputParameters = AVMutableAudioMixInputParameters(track: assetMusicTrack)
        musicParam.trackID = compositionAudioMusic.trackID


        //Set final volume of the audio record and the music
        videoParam.setVolume(volumeVideo, at: kCMTimeZero)
        musicParam.setVolume(volumeAudio, at: kCMTimeZero)

        //Add setting
        audioMixParam.append(musicParam)
        audioMixParam.append(videoParam)

        //Add audio on final record
        //First: the audio of the record and Second: the music
        do {
            try compositionAudioVideo.insertTimeRange(CMTimeRangeMake(kCMTimeZero, assetVideo.duration), of: assetVideoTrack, at: kCMTimeZero)
        } catch _ {
            assertionFailure()
        }

        do {
            try compositionAudioMusic.insertTimeRange(CMTimeRangeMake(CMTimeMake(Int64(startAudioTime * 10000), 10000), assetVideo.duration), of: assetMusicTrack, at: kCMTimeZero)
        } catch _ {
            assertionFailure()
        }

        //Add parameter
        audioMix.inputParameters = audioMixParam

        //Remove the previous temp video if exist
        let filemgr = FileManager.default
        do {
            if filemgr.fileExists(atPath: "\(docsDir)/movie-merge-music.mov") {
                try filemgr.removeItem(atPath: "\(docsDir)/movie-merge-music.mov")
            } else {
            }
        } catch _ {
        }

        //Exporte the final record’
        let completeMovie = "\(docsDir)/movie-merge-music.mov"
        let completeMovieUrl = NSURL(fileURLWithPath: completeMovie)
        let exporter: AVAssetExportSession = AVAssetExportSession(asset: composition, presetName: AVAssetExportPresetHighestQuality)!
        exporter.outputURL = completeMovieUrl as URL
        exporter.outputFileType = AVFileTypeMPEG4
        exporter.audioMix = audioMix

        exporter.exportAsynchronously(completionHandler: {
            DispatchQueue.main.async { _ in
                self.exportDidFinish(exporter)
            }
        })
    }


    func exportDidFinish(_ session: AVAssetExportSession) {
        if session.status == AVAssetExportSessionStatus.completed {
            let outputURL = session.outputURL

            PHPhotoLibrary.shared().performChanges({
                PHAssetChangeRequest.creationRequestForAssetFromVideo(atFileURL: outputURL!)
            }) { saved, error in
                if saved {
                    let alertController = UIAlertController(title: "Your video was successfully saved", message: nil, preferredStyle: .alert)
                    let defaultAction = UIAlertAction(title: "OK", style: .default, handler: nil)
                    alertController.addAction(defaultAction)
                    self.present(alertController, animated: true, completion: nil)
                }
            }
        }
    }

Моя проблема: теперь я должен добавитьWatermark изображение на финалеVideo перед сохранением вDevice gallery.

Я проверилSwift 3: Как добавить водяной знак на видео? AVVideoCompositionCoreAnimationTool iOS 10 выпуск но после применения водяного знака видео появляется в небольшом размере кадра.

Примечание. Вот мой класс, который я использую для добавления водяных знаков:

import Foundation

import UIKit
import AssetsLibrary
import AVFoundation
import Photos

enum QUWatermarkPosition {
    case TopLeft
    case TopRight
    case BottomLeft
    case BottomRight
    case Default
}

class VideoWatermarkManager: NSObject {

    func watermark(video videoAsset:AVAsset, watermarkText text : String, saveToLibrary flag : Bool, watermarkPosition position : QUWatermarkPosition, completion : ((_ status : AVAssetExportSessionStatus?, _ session: AVAssetExportSession?, _ outputURL : URL?) -> ())?) {
        self.watermark(video: videoAsset, watermarkText: text, imageName: nil, saveToLibrary: flag, watermarkPosition: position) { (status, session, outputURL) -> () in
            completion!(status, session, outputURL)
        }
    }

    func watermark(video videoAsset:AVAsset, imageName name : String, saveToLibrary flag : Bool, watermarkPosition position : QUWatermarkPosition, completion : ((_ status : AVAssetExportSessionStatus?, _ session: AVAssetExportSession?, _ outputURL : URL?) -> ())?) {
        self.watermark(video: videoAsset, watermarkText: nil, imageName: name, saveToLibrary: flag, watermarkPosition: position) { (status, session, outputURL) -> () in
            completion!(status, session, outputURL)
        }
    }

    private func watermark(video videoAsset:AVAsset, watermarkText text : String!, imageName name : String!, saveToLibrary flag : Bool, watermarkPosition position : QUWatermarkPosition, completion : ((_ status : AVAssetExportSessionStatus?, _ session: AVAssetExportSession?, _ outputURL : URL?) -> ())?) {
        DispatchQueue.global(qos: DispatchQoS.QoSClass.default).async {

            let mixComposition = AVMutableComposition()

            let compositionVideoTrack = mixComposition.addMutableTrack(withMediaType: AVMediaTypeVideo, preferredTrackID: Int32(kCMPersistentTrackID_Invalid))
            let clipVideoTrack = videoAsset.tracks(withMediaType: AVMediaTypeVideo)[0]
            do {
                try compositionVideoTrack.insertTimeRange(CMTimeRangeMake(kCMTimeZero, videoAsset.duration), of: clipVideoTrack, at: kCMTimeZero)
            }
            catch {
                print(error.localizedDescription)
            }

            let videoSize = clipVideoTrack.naturalSize

            let parentLayer = CALayer()
            let videoLayer = CALayer()
            parentLayer.frame = CGRect(x: 0, y: 0, width: videoSize.width, height: videoSize.height)
            videoLayer.frame = CGRect(x: 0, y: 0, width: videoSize.width, height: videoSize.height)
            parentLayer.addSublayer(videoLayer)


                let watermarkImage = UIImage(named: name)
                let imageLayer = CALayer()
                imageLayer.contents = watermarkImage?.cgImage

                var xPosition : CGFloat = 0.0
                var yPosition : CGFloat = 0.0
                let imageSize : CGFloat = 57.0

                switch (position) {
                case .TopLeft:
                    xPosition = 0
                    yPosition = 0
                    break
                case .TopRight:
                    xPosition = videoSize.width - imageSize
                    yPosition = 0
                    break
                case .BottomLeft:
                    xPosition = 0
                    yPosition = videoSize.height - imageSize
                    break
                case .BottomRight, .Default:
                    xPosition = videoSize.width - imageSize
                    yPosition = videoSize.height - imageSize
                    break
                }


                imageLayer.frame = CGRect(x: xPosition, y: yPosition, width: imageSize, height: imageSize)
                imageLayer.opacity = 0.85
                parentLayer.addSublayer(imageLayer)


            let videoComp = AVMutableVideoComposition()
            videoComp.renderSize = videoSize
            videoComp.frameDuration = CMTimeMake(1, 30)
            videoComp.renderScale = 1.0
            videoComp.animationTool = AVVideoCompositionCoreAnimationTool(postProcessingAsVideoLayer: videoLayer, in: parentLayer)

            let instruction = AVMutableVideoCompositionInstruction()
            instruction.timeRange = CMTimeRangeMake(kCMTimeZero, mixComposition.duration)
            _ = mixComposition.tracks(withMediaType: AVMediaTypeVideo)[0] as AVAssetTrack

            let layerInstruction = self.videoCompositionInstructionForTrack(track: compositionVideoTrack, asset: videoAsset)

            instruction.layerInstructions = [layerInstruction]
            videoComp.instructions = [instruction]

            let documentDirectory = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)[0]
            let dateFormatter = DateFormatter()
            dateFormatter.dateStyle = .long
            dateFormatter.timeStyle = .short
            let date = dateFormatter.string(from: Date())
            let url = URL(fileURLWithPath: documentDirectory).appendingPathComponent("watermarkVideo-\(date).mov")

            let exporter = AVAssetExportSession(asset: mixComposition, presetName: AVAssetExportPresetHighestQuality)
            exporter?.outputURL = url
            exporter?.outputFileType = AVFileTypeQuickTimeMovie
            exporter?.shouldOptimizeForNetworkUse = true
            exporter?.videoComposition = videoComp

            exporter?.exportAsynchronously() {
                DispatchQueue.main.async {

                    if exporter?.status == AVAssetExportSessionStatus.completed {
                        let outputURL = exporter?.outputURL
                        if flag {
                            // Save to library
                            //                            let library = ALAssetsLibrary()

                            if UIVideoAtPathIsCompatibleWithSavedPhotosAlbum(outputURL!.path) {
                                PHPhotoLibrary.shared().performChanges({
                                    PHAssetChangeRequest.creationRequestForAssetFromVideo(atFileURL: outputURL!)
                                }) { saved, error in
                                    if saved {
                                        completion!(AVAssetExportSessionStatus.completed, exporter, outputURL)
                                    }
                                }
                            }

                            //                            if library.videoAtPathIs(compatibleWithSavedPhotosAlbum: outputURL) {
                            //                                library.writeVideoAtPathToSavedPhotosAlbum(outputURL,
                            //                                                                           completionBlock: { (assetURL:NSURL!, error:NSError!) -> Void in
                            //
                            //                                                                            completion!(AVAssetExportSessionStatus.Completed, exporter, outputURL)
                            //                                })
                            //                            }
                        } else {
                            completion!(AVAssetExportSessionStatus.completed, exporter, outputURL)
                        }

                    } else {
                        // Error
                        completion!(exporter?.status, exporter, nil)
                    }
                }
            }
        }
    }


    private func orientationFromTransform(transform: CGAffineTransform) -> (orientation: UIImageOrientation, isPortrait: Bool) {
        var assetOrientation = UIImageOrientation.up
        var isPortrait = false
        if transform.a == 0 && transform.b == 1.0 && transform.c == -1.0 && transform.d == 0 {
            assetOrientation = .right
            isPortrait = true
        } else if transform.a == 0 && transform.b == -1.0 && transform.c == 1.0 && transform.d == 0 {
            assetOrientation = .left
            isPortrait = true
        } else if transform.a == 1.0 && transform.b == 0 && transform.c == 0 && transform.d == 1.0 {
            assetOrientation = .up
        } else if transform.a == -1.0 && transform.b == 0 && transform.c == 0 && transform.d == -1.0 {
            assetOrientation = .down
        }
        return (assetOrientation, isPortrait)
    }

    private func videoCompositionInstructionForTrack(track: AVCompositionTrack, asset: AVAsset) -> AVMutableVideoCompositionLayerInstruction {
        let instruction = AVMutableVideoCompositionLayerInstruction(assetTrack: track)
        let assetTrack = asset.tracks(withMediaType: AVMediaTypeVideo)[0]

        let transform = assetTrack.preferredTransform
        let assetInfo = orientationFromTransform(transform: transform)

        var scaleToFitRatio = UIScreen.main.bounds.width / assetTrack.naturalSize.width
        if assetInfo.isPortrait {
            scaleToFitRatio = UIScreen.main.bounds.width / assetTrack.naturalSize.height
            let scaleFactor = CGAffineTransform(scaleX: scaleToFitRatio, y: scaleToFitRatio)
            instruction.setTransform(assetTrack.preferredTransform.concatenating(scaleFactor),
                                     at: kCMTimeZero)
        } else {
            let scaleFactor = CGAffineTransform(scaleX: scaleToFitRatio, y: scaleToFitRatio)
            var concat = assetTrack.preferredTransform.concatenating(scaleFactor).concatenating(CGAffineTransform(translationX: 0, y: UIScreen.main.bounds.width / 2))
            if assetInfo.orientation == .down {
                let fixUpsideDown = CGAffineTransform(rotationAngle: CGFloat(Double.pi))
                let windowBounds = UIScreen.main.bounds
                let yFix = assetTrack.naturalSize.height + windowBounds.height
                let centerFix = CGAffineTransform(translationX: assetTrack.naturalSize.width, y: yFix)
                concat = fixUpsideDown.concatenating(centerFix).concatenating(scaleFactor)
            }
            instruction.setTransform(concat, at: kCMTimeZero)
        }

        return instruction
    }
}

Может ли кто-нибудь помочь мне, как я могу добавитьWatermark на моемVideo?