使用Swift将音频和视频文件合并成一个视频

Question

使用Swift将音频和视频文件合并成一个视频

27

我用Swift编写了一个程序。我想将视频与音频文件合并，但是出现了这个错误。

"failed Error Domain=AVFoundationErrorDomain Code=-11838 "Operation Stopped" UserInfo=0x17da4230 {NSLocalizedDescription=Operation Stopped, NSLocalizedFailureReason=The operation is not supported for this media.}"

代码

func mergeAudio(audioURL: NSURL, moviePathUrl: NSURL, savePathUrl: NSURL) {
    var composition = AVMutableComposition()
    let trackVideo:AVMutableCompositionTrack = composition.addMutableTrackWithMediaType(AVMediaTypeVideo, preferredTrackID: CMPersistentTrackID())
    let trackAudio:AVMutableCompositionTrack = composition.addMutableTrackWithMediaType(AVMediaTypeAudio, preferredTrackID: CMPersistentTrackID())
    let option = NSDictionary(object: true, forKey: "AVURLAssetPreferPreciseDurationAndTimingKey")
    let sourceAsset = AVURLAsset(URL: moviePathUrl, options: option as [NSObject : AnyObject])
    let audioAsset = AVURLAsset(URL: audioURL, options: option as [NSObject : AnyObject])

    let tracks = sourceAsset.tracksWithMediaType(AVMediaTypeVideo)
    let audios = audioAsset.tracksWithMediaType(AVMediaTypeAudio)

    if tracks.count > 0 {
        let assetTrack:AVAssetTrack = tracks[0] as! AVAssetTrack
        let assetTrackAudio:AVAssetTrack = audios[0] as! AVAssetTrack

        let audioDuration:CMTime = assetTrackAudio.timeRange.duration
        let audioSeconds:Float64 = CMTimeGetSeconds(assetTrackAudio.timeRange.duration)

        trackVideo.insertTimeRange(CMTimeRangeMake(kCMTimeZero,audioDuration), ofTrack: assetTrack, atTime: kCMTimeZero, error: nil)
        trackAudio.insertTimeRange(CMTimeRangeMake(kCMTimeZero,audioDuration), ofTrack: assetTrackAudio, atTime: kCMTimeZero, error: nil)
    }

    var assetExport: AVAssetExportSession = AVAssetExportSession(asset: composition, presetName: AVAssetExportPresetPassthrough)
    assetExport.outputFileType = AVFileTypeMPEG4
    assetExport.outputURL = savePathUrl
    self.tmpMovieURL = savePathUrl
    assetExport.shouldOptimizeForNetworkUse = true
    assetExport.exportAsynchronouslyWithCompletionHandler { () -> Void in
        switch assetExport.status {
        case AVAssetExportSessionStatus.Completed:
            let assetsLib = ALAssetsLibrary()
            assetsLib.writeVideoAtPathToSavedPhotosAlbum(savePathUrl, completionBlock: nil)
            println("success")
        case  AVAssetExportSessionStatus.Failed:
            println("failed \(assetExport.error)")
        case AVAssetExportSessionStatus.Cancelled:
            println("cancelled \(assetExport.error)")
        default:
            println("complete")
        }
    }

}

在我看来，像mpeg4这样的媒体类型是错误的。问题出在哪里？我错过了什么吗？

- Kei Maejima

你解决了你的问题吗？ - DShah

还没有。仍在寻找解决方案。 - Kei Maejima

你最终解决了这个问题吗？ - user3344977

6个回答

15

在上述问题中，我发现了同样的错误，原因是savePathUrl错了，目标URL应该像下面的代码一样包括新的视频名称。

我正在寻找合并音频和视频文件的代码，但无论在哪里都找不到，所以在阅读苹果文档几个小时后，我编写了这段代码。

注意：这是经过测试的100％工作的代码。

步骤1：在您的视图控制器中导入这些模块。

import UIKit
import AVFoundation
import AVKit
import AssetsLibrary

步骤 2：将此函数添加到您的代码中

func mergeFilesWithUrl(videoUrl:NSURL, audioUrl:NSURL)
{
    let mixComposition : AVMutableComposition = AVMutableComposition()
    var mutableCompositionVideoTrack : [AVMutableCompositionTrack] = []
    var mutableCompositionAudioTrack : [AVMutableCompositionTrack] = []
    let totalVideoCompositionInstruction : AVMutableVideoCompositionInstruction = AVMutableVideoCompositionInstruction()


    //start merge

    let aVideoAsset : AVAsset = AVAsset(URL: videoUrl)
    let aAudioAsset : AVAsset = AVAsset(URL: audioUrl)

    mutableCompositionVideoTrack.append(mixComposition.addMutableTrackWithMediaType(AVMediaTypeVideo, preferredTrackID: kCMPersistentTrackID_Invalid))
    mutableCompositionAudioTrack.append( mixComposition.addMutableTrackWithMediaType(AVMediaTypeAudio, preferredTrackID: kCMPersistentTrackID_Invalid))

    let aVideoAssetTrack : AVAssetTrack = aVideoAsset.tracksWithMediaType(AVMediaTypeVideo)[0]
    let aAudioAssetTrack : AVAssetTrack = aAudioAsset.tracksWithMediaType(AVMediaTypeAudio)[0]



    do{
        try mutableCompositionVideoTrack[0].insertTimeRange(CMTimeRangeMake(kCMTimeZero, aVideoAssetTrack.timeRange.duration), ofTrack: aVideoAssetTrack, atTime: kCMTimeZero)

        //In my case my audio file is longer then video file so i took videoAsset duration
        //instead of audioAsset duration

        try mutableCompositionAudioTrack[0].insertTimeRange(CMTimeRangeMake(kCMTimeZero, aVideoAssetTrack.timeRange.duration), ofTrack: aAudioAssetTrack, atTime: kCMTimeZero)

        //Use this instead above line if your audiofile and video file's playing durations are same

        //            try mutableCompositionAudioTrack[0].insertTimeRange(CMTimeRangeMake(kCMTimeZero, aVideoAssetTrack.timeRange.duration), ofTrack: aAudioAssetTrack, atTime: kCMTimeZero)

    }catch{

    }

    totalVideoCompositionInstruction.timeRange = CMTimeRangeMake(kCMTimeZero,aVideoAssetTrack.timeRange.duration )

    let mutableVideoComposition : AVMutableVideoComposition = AVMutableVideoComposition()
    mutableVideoComposition.frameDuration = CMTimeMake(1, 30)

    mutableVideoComposition.renderSize = CGSizeMake(1280,720)

    //        playerItem = AVPlayerItem(asset: mixComposition)
    //        player = AVPlayer(playerItem: playerItem!)
    //
    //
    //        AVPlayerVC.player = player



    //find your video on this URl
    let savePathUrl : NSURL = NSURL(fileURLWithPath: NSHomeDirectory() + "/Documents/newVideo.mp4")

    let assetExport: AVAssetExportSession = AVAssetExportSession(asset: mixComposition, presetName: AVAssetExportPresetHighestQuality)!
    assetExport.outputFileType = AVFileTypeMPEG4
    assetExport.outputURL = savePathUrl
    assetExport.shouldOptimizeForNetworkUse = true

    assetExport.exportAsynchronouslyWithCompletionHandler { () -> Void in
        switch assetExport.status {

        case AVAssetExportSessionStatus.Completed:

            //Uncomment this if u want to store your video in asset

            //let assetsLib = ALAssetsLibrary()
            //assetsLib.writeVideoAtPathToSavedPhotosAlbum(savePathUrl, completionBlock: nil)

            print("success")
        case  AVAssetExportSessionStatus.Failed:
            print("failed \(assetExport.error)")
        case AVAssetExportSessionStatus.Cancelled:
            print("cancelled \(assetExport.error)")
        default:
            print("complete")
        }
    }


}

步骤3：在您想要的位置调用函数，如下所示

let videoUrl : NSURL =  NSURL(fileURLWithPath: NSBundle.mainBundle().pathForResource("SampleVideo", ofType: "mp4")!)
let audioUrl : NSURL = NSURL(fileURLWithPath: NSBundle.mainBundle().pathForResource("SampleAudio", ofType: "mp3")!)

mergeFilesWithUrl(videoUrl, audioUrl: audioUrl)

希望这可以对你有所帮助，节省你的时间。

- Govind Prajapati

1

如果录制的声音格式为AVFileTypeAppleM4A，则它无法正常工作，有什么建议吗？ - Dumitru Rogojinaru

如果我添加自定义音频，视频的原始音频将被删除。我想要保留原始视频的声音，并添加我的自定义声音。你能帮我吗？ - parth

抱歉朋友，我只有以上的代码，没有时间再深入探索了。 - Govind Prajapati

1

@parth 嘿，老兄，我找到了一个解决方案。看看这个链接 https://dev59.com/26Pia4cB1Zd3GeqP3cEw#45327843 - Faruk

与'mutableVideoComposition'相关的三行是无用的，应该删除。 - rommex

@DumitruRogojinaru，关于M4A格式你找到解决方案了吗？ - rommex

8

Swift 4.2 / 5

func mergeVideoWithAudio(videoUrl: URL, audioUrl: URL, success: @escaping ((URL) -> Void), failure: @escaping ((Error?) -> Void)) {


    let mixComposition: AVMutableComposition = AVMutableComposition()
    var mutableCompositionVideoTrack: [AVMutableCompositionTrack] = []
    var mutableCompositionAudioTrack: [AVMutableCompositionTrack] = []
    let totalVideoCompositionInstruction : AVMutableVideoCompositionInstruction = AVMutableVideoCompositionInstruction()

    let aVideoAsset: AVAsset = AVAsset(url: videoUrl)
    let aAudioAsset: AVAsset = AVAsset(url: audioUrl)

    if let videoTrack = mixComposition.addMutableTrack(withMediaType: .video, preferredTrackID: kCMPersistentTrackID_Invalid), let audioTrack = mixComposition.addMutableTrack(withMediaType: .audio, preferredTrackID: kCMPersistentTrackID_Invalid) {
        mutableCompositionVideoTrack.append(videoTrack)
        mutableCompositionAudioTrack.append(audioTrack)

    if let aVideoAssetTrack: AVAssetTrack = aVideoAsset.tracks(withMediaType: .video).first, let aAudioAssetTrack: AVAssetTrack = aAudioAsset.tracks(withMediaType: .audio).first {
        do {
            try mutableCompositionVideoTrack.first?.insertTimeRange(CMTimeRangeMake(start: CMTime.zero, duration: aVideoAssetTrack.timeRange.duration), of: aVideoAssetTrack, at: CMTime.zero)
            try mutableCompositionAudioTrack.first?.insertTimeRange(CMTimeRangeMake(start: CMTime.zero, duration: aVideoAssetTrack.timeRange.duration), of: aAudioAssetTrack, at: CMTime.zero)
               videoTrack.preferredTransform = aVideoAssetTrack.preferredTransform 

        } catch{
            print(error)
        }


       totalVideoCompositionInstruction.timeRange = CMTimeRangeMake(start: CMTime.zero,duration: aVideoAssetTrack.timeRange.duration)
    }
    }

    let mutableVideoComposition: AVMutableVideoComposition = AVMutableVideoComposition()
    mutableVideoComposition.frameDuration = CMTimeMake(value: 1, timescale: 30)
    mutableVideoComposition.renderSize = CGSize(width: 480, height: 640)

    if let documentsPath = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true).first {
        let outputURL = URL(fileURLWithPath: documentsPath).appendingPathComponent("\("fileName").m4v")

        do {
            if FileManager.default.fileExists(atPath: outputURL.path) {

                try FileManager.default.removeItem(at: outputURL)
            }
        } catch { }

        if let exportSession = AVAssetExportSession(asset: mixComposition, presetName: AVAssetExportPresetHighestQuality) {
            exportSession.outputURL = outputURL
            exportSession.outputFileType = AVFileType.mp4
            exportSession.shouldOptimizeForNetworkUse = true

            /// try to export the file and handle the status cases
            exportSession.exportAsynchronously(completionHandler: {
                switch exportSession.status {
                case .failed:
                    if let _error = exportSession.error {
                        failure(_error)
                    }

                case .cancelled:
                    if let _error = exportSession.error {
                        failure(_error)
                    }

                default:
                    print("finished")
                    success(outputURL)
                }
            })
        } else {
            failure(nil)
        }
    }
}

- Sh_Khan

1

我能合并两个wav文件吗？ - Paresh. P

3

新版本Swift3具备URL和新语法。

func mergeFilesWithUrl(videoUrl:URL, audioUrl:URL)
{
    let mixComposition : AVMutableComposition = AVMutableComposition()
    var mutableCompositionVideoTrack : [AVMutableCompositionTrack] = []
    var mutableCompositionAudioTrack : [AVMutableCompositionTrack] = []
    let totalVideoCompositionInstruction : AVMutableVideoCompositionInstruction = AVMutableVideoCompositionInstruction()


    //start merge

    let aVideoAsset : AVAsset = AVAsset(url: videoUrl)
    let aAudioAsset : AVAsset = AVAsset(url: audioUrl)

    mutableCompositionVideoTrack.append(mixComposition.addMutableTrack(withMediaType: AVMediaTypeVideo, preferredTrackID: kCMPersistentTrackID_Invalid))
    mutableCompositionAudioTrack.append( mixComposition.addMutableTrack(withMediaType: AVMediaTypeAudio, preferredTrackID: kCMPersistentTrackID_Invalid))

    let aVideoAssetTrack : AVAssetTrack = aVideoAsset.tracks(withMediaType: AVMediaTypeVideo)[0]
    let aAudioAssetTrack : AVAssetTrack = aAudioAsset.tracks(withMediaType: AVMediaTypeAudio)[0]



    do{
        try mutableCompositionVideoTrack[0].insertTimeRange(CMTimeRangeMake(kCMTimeZero, aVideoAssetTrack.timeRange.duration), of: aVideoAssetTrack, at: kCMTimeZero)

        //In my case my audio file is longer then video file so i took videoAsset duration
        //instead of audioAsset duration

        try mutableCompositionAudioTrack[0].insertTimeRange(CMTimeRangeMake(kCMTimeZero, aVideoAssetTrack.timeRange.duration), of: aAudioAssetTrack, at: kCMTimeZero)

        //Use this instead above line if your audiofile and video file's playing durations are same

        //            try mutableCompositionAudioTrack[0].insertTimeRange(CMTimeRangeMake(kCMTimeZero, aVideoAssetTrack.timeRange.duration), ofTrack: aAudioAssetTrack, atTime: kCMTimeZero)

    }catch{

    }

    totalVideoCompositionInstruction.timeRange = CMTimeRangeMake(kCMTimeZero,aVideoAssetTrack.timeRange.duration )

    let mutableVideoComposition : AVMutableVideoComposition = AVMutableVideoComposition()
    mutableVideoComposition.frameDuration = CMTimeMake(1, 30)

    mutableVideoComposition.renderSize = CGSize(width: 1280, height: 720)
    //        playerItem = AVPlayerItem(asset: mixComposition)
    //        player = AVPlayer(playerItem: playerItem!)
    //
    //
    //        AVPlayerVC.player = player

    //find your video on this URl
    let savePathUrl : URL = URL(fileURLWithPath: NSHomeDirectory() + "/Documents/newVideo.mp4")

    let assetExport: AVAssetExportSession = AVAssetExportSession(asset: mixComposition, presetName: AVAssetExportPresetHighestQuality)!
    assetExport.outputFileType = AVFileTypeMPEG4
    assetExport.outputURL = savePathUrl
    assetExport.shouldOptimizeForNetworkUse = true

    assetExport.exportAsynchronously { () -> Void in
        switch assetExport.status {

        case AVAssetExportSessionStatus.completed:

            //Uncomment this if u want to store your video in asset

            //let assetsLib = ALAssetsLibrary()
            //assetsLib.writeVideoAtPathToSavedPhotosAlbum(savePathUrl, completionBlock: nil)

            print("success")
        case  AVAssetExportSessionStatus.failed:
            print("failed \(assetExport.error)")
        case AVAssetExportSessionStatus.cancelled:
            print("cancelled \(assetExport.error)")
        default:
            print("complete")
        }
    }
}

- Matthieu Lemonnier

有没有办法合并两个WAV文件？我在assetExport?.exportAsynchronously(completionHandler: { [weak self] in})时遇到了崩溃问题。 - Paresh. P

2

Swift 5版本（如果视频大于音频，则重复音频）：只需传递音频和视频URL。我已经尝试了本地视频和远程音频URL。

func mergeVideoWithAudio(videoUrl: URL,
                                audioUrl: URL,
                                success: @escaping ((URL) -> Void),
                                failure: @escaping ((Error?) -> Void)) {

       let mixComposition: AVMutableComposition = AVMutableComposition()
       var mutableCompositionVideoTrack: [AVMutableCompositionTrack] = []
       var mutableCompositionAudioTrack: [AVMutableCompositionTrack] = []
       let totalVideoCompositionInstruction: AVMutableVideoCompositionInstruction = AVMutableVideoCompositionInstruction()

       let aVideoAsset: AVAsset = AVAsset(url: videoUrl)
       let aAudioAsset: AVAsset = AVAsset(url: audioUrl)

       if let videoTrack = mixComposition.addMutableTrack(withMediaType: .video, preferredTrackID: kCMPersistentTrackID_Invalid), let audioTrack = mixComposition.addMutableTrack(withMediaType: .audio, preferredTrackID: kCMPersistentTrackID_Invalid) {
           mutableCompositionVideoTrack.append( videoTrack )
           mutableCompositionAudioTrack.append( audioTrack )

           if let aVideoAssetTrack: AVAssetTrack = aVideoAsset.tracks(withMediaType: .video).first, let aAudioAssetTrack: AVAssetTrack = aAudioAsset.tracks(withMediaType: .audio).first {
               do {
                   try mutableCompositionVideoTrack.first?.insertTimeRange(CMTimeRangeMake(start: CMTime.zero, duration: aVideoAssetTrack.timeRange.duration), of: aVideoAssetTrack, at: CMTime.zero)

                   let videoDuration = aVideoAsset.duration
                   if CMTimeCompare(videoDuration, aAudioAsset.duration) == -1 {
                       try mutableCompositionAudioTrack.first?.insertTimeRange(CMTimeRangeMake(start: CMTime.zero, duration: aVideoAssetTrack.timeRange.duration), of: aAudioAssetTrack, at: CMTime.zero)
                   } else if CMTimeCompare(videoDuration, aAudioAsset.duration) == 1 {
                       var currentTime = CMTime.zero
                       while true {
                           var audioDuration = aAudioAsset.duration
                           let totalDuration = CMTimeAdd(currentTime, audioDuration)
                           if CMTimeCompare(totalDuration, videoDuration) == 1 {
                               audioDuration = CMTimeSubtract(totalDuration, videoDuration)
                           }
                           try mutableCompositionAudioTrack.first?.insertTimeRange(CMTimeRangeMake(start: CMTime.zero, duration: aVideoAssetTrack.timeRange.duration), of: aAudioAssetTrack, at: currentTime)

                           currentTime = CMTimeAdd(currentTime, audioDuration)
                           if CMTimeCompare(currentTime, videoDuration) == 1 || CMTimeCompare(currentTime, videoDuration) == 0 {
                               break
                           }
                       }
                   }
                   videoTrack.preferredTransform = aVideoAssetTrack.preferredTransform

               } catch {
                   print(error)
               }

               totalVideoCompositionInstruction.timeRange = CMTimeRangeMake(start: CMTime.zero, duration: aVideoAssetTrack.timeRange.duration)
           }
       }

       let mutableVideoComposition: AVMutableVideoComposition = AVMutableVideoComposition()
       mutableVideoComposition.frameDuration = CMTimeMake(value: 1, timescale: 30)
       mutableVideoComposition.renderSize = CGSize(width: 480, height: 640)

       if let documentsPath = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true).first {
           let outputURL = URL(fileURLWithPath: documentsPath).appendingPathComponent("\("fileName").m4v")

           do {
               if FileManager.default.fileExists(atPath: outputURL.path) {

                   try FileManager.default.removeItem(at: outputURL)
               }
           } catch { }

           if let exportSession = AVAssetExportSession(asset: mixComposition, presetName: AVAssetExportPresetHighestQuality) {
               exportSession.outputURL = outputURL
               exportSession.outputFileType = AVFileType.mp4
               exportSession.shouldOptimizeForNetworkUse = true

               // try to export the file and handle the status cases
               exportSession.exportAsynchronously(completionHandler: {
                   switch exportSession.status {
                   case .failed:
                       if let error = exportSession.error {
                           failure(error)
                       }

                   case .cancelled:
                       if let error = exportSession.error {
                           failure(error)
                       }

                   default:
                       print("finished")
                       success(outputURL)
                   }
               })
           } else {
               failure(nil)
           }
       }
   }

- Sagar Pathak

0

已更新至 Swift 并发编程（Swift 5.7）

一些需要抛出的错误：

enum VideoAudioMergeError: Error {
    case compositionAddVideoFailed, compositionAddAudioFailed, compositionAddAudioOfVideoFailed, unknownError
}

还有这个方法：

/// Merges video and sound while keeping sound of the video too
///
/// - Parameters:
///   - videoUrl: URL to video file
///   - audioUrl: URL to audio file
///   - shouldFlipHorizontally: pass True if video was recorded using frontal camera otherwise pass False
func mergeVideoAndAudio(videoUrl: URL,
                        audioUrl: URL,
                        shouldFlipHorizontally: Bool = false) async throws -> URL {

    let mixComposition = AVMutableComposition()
    var mutableCompositionVideoTrack = [AVMutableCompositionTrack]()
    var mutableCompositionAudioTrack = [AVMutableCompositionTrack]()
    var mutableCompositionAudioOfVideoTrack = [AVMutableCompositionTrack]()

    //start merge

    let aVideoAsset = AVAsset(url: videoUrl)
    let aAudioAsset = AVAsset(url: audioUrl)

    guard let compositionAddVideo = mixComposition.addMutableTrack(withMediaType: AVMediaType.video,
                                                                   preferredTrackID: kCMPersistentTrackID_Invalid) else {
        throw VideoAudioMergeError.compositionAddVideoFailed
    }

    guard let compositionAddAudio = mixComposition.addMutableTrack(withMediaType: AVMediaType.audio,
                                                                   preferredTrackID: kCMPersistentTrackID_Invalid) else {
        throw VideoAudioMergeError.compositionAddAudioFailed
    }

    guard let compositionAddAudioOfVideo = mixComposition.addMutableTrack(withMediaType: AVMediaType.audio,
                                                                          preferredTrackID: kCMPersistentTrackID_Invalid) else {
        throw VideoAudioMergeError.compositionAddAudioOfVideoFailed
    }

    do {
        let aVideoAssetTrack: AVAssetTrack = try await aVideoAsset.loadTracks(withMediaType: AVMediaType.video)[0]
        let aAudioOfVideoAssetTrack: AVAssetTrack? = try await  aVideoAsset.loadTracks(withMediaType: AVMediaType.audio).first
        let aAudioAssetTrack: AVAssetTrack = try await aAudioAsset.loadTracks(withMediaType: AVMediaType.audio)[0]

        // Default must have transformation
        compositionAddVideo.preferredTransform = try await aVideoAssetTrack.load(.preferredTransform)

        if shouldFlipHorizontally {
            // Flip video horizontally
            var frontalTransform: CGAffineTransform = CGAffineTransform(scaleX: -1.0, y: 1.0)
            let naturalSize = try await aVideoAssetTrack.load(.naturalSize)
            frontalTransform = frontalTransform.translatedBy(x: -naturalSize.width, y: 0.0)
            frontalTransform = frontalTransform.translatedBy(x: 0.0, y: -naturalSize.width)
            compositionAddVideo.preferredTransform = frontalTransform
        }

        mutableCompositionVideoTrack.append(compositionAddVideo)
        mutableCompositionAudioTrack.append(compositionAddAudio)
        mutableCompositionAudioOfVideoTrack.append(compositionAddAudioOfVideo)
        
        let videoTimeRange = try await aVideoAssetTrack.load(.timeRange)

        try mutableCompositionVideoTrack[0].insertTimeRange(CMTimeRangeMake(start: CMTime.zero,
                                                                            duration: videoTimeRange.duration),
                                                            of: aVideoAssetTrack,
                                                            at: CMTime.zero)

        //In my case my audio file is longer then video file so i took videoAsset duration
        //instead of audioAsset duration
        try mutableCompositionAudioTrack[0].insertTimeRange(CMTimeRangeMake(start: CMTime.zero,
                                                                            duration: videoTimeRange.duration),
                                                            of: aAudioAssetTrack,
                                                            at: CMTime.zero)

        // adding audio (of the video if exists) asset to the final composition
        if let aAudioOfVideoAssetTrack = aAudioOfVideoAssetTrack {
            try mutableCompositionAudioOfVideoTrack[0].insertTimeRange(CMTimeRangeMake(start: CMTime.zero,
                                                                                       duration: videoTimeRange.duration),
                                                                       of: aAudioOfVideoAssetTrack,
                                                                       at: CMTime.zero)
        }
    } catch {
        throw error
    }

    // Exporting
    let savePathUrl: URL = URL(fileURLWithPath: NSHomeDirectory() + "/Documents/newVideo.mp4")
    do { // delete old video
        try FileManager.default.removeItem(at: savePathUrl)
    } catch { print(error.localizedDescription) }

    let assetExport: AVAssetExportSession = AVAssetExportSession(asset: mixComposition, presetName: AVAssetExportPresetHighestQuality)!
    assetExport.outputFileType = AVFileType.mp4
    assetExport.outputURL = savePathUrl
    assetExport.shouldOptimizeForNetworkUse = true

    await assetExport.export()
    
    if assetExport.status == .completed {
        return savePathUrl
    }
    
    if let error = assetExport.error {
        throw error
    } else {
        throw VideoAudioMergeError.unknownError
    }
}

- Matt54

网页内容由stack overflow 提供, 点击上面的

可以查看英文原文，
原文链接

- Tung Fam · Accepted Answer

改进代码（Govind的答案）并添加了一些额外的功能：

合并视频的音频 + 外部音频（初始答案会丢失视频的声音）

水平翻转视频（如果需要的话，我个人在用户使用前置摄像头拍摄时使用它，顺便说一句Instagram也会翻转）

正确应用preferredTransform，解决了视频保存后旋转的问题（视频是外部的：由其他设备捕获/由其他应用程序生成）

删除了一些与VideoComposition无关的未使用的代码

为该方法添加了一个完成处理程序，以便可以从不同的类中调用

更新到Swift 4

步骤1。

import UIKit import AVFoundation import AVKit import AssetsLibrary

第二步。
/// Merges video and sound while keeping sound of the video too /// /// - Parameters: /// - videoUrl: URL to video file /// - audioUrl: URL to audio file /// - shouldFlipHorizontally: pass True if video was recorded using frontal camera otherwise pass False /// - completion: completion of saving: error or url with final video func mergeVideoAndAudio(videoUrl: URL, audioUrl: URL, shouldFlipHorizontally: Bool = false, completion: @escaping (_ error: Error?, _ url: URL?) -> Void) { let mixComposition = AVMutableComposition() var mutableCompositionVideoTrack = [AVMutableCompositionTrack]() var mutableCompositionAudioTrack = [AVMutableCompositionTrack]() var mutableCompositionAudioOfVideoTrack = [AVMutableCompositionTrack]() //start merge let aVideoAsset = AVAsset(url: videoUrl) let aAudioAsset = AVAsset(url: audioUrl) let compositionAddVideo = mixComposition.addMutableTrack(withMediaType: AVMediaType.video, preferredTrackID: kCMPersistentTrackID_Invalid)! let compositionAddAudio = mixComposition.addMutableTrack(withMediaType: AVMediaType.audio, preferredTrackID: kCMPersistentTrackID_Invalid)! let compositionAddAudioOfVideo = mixComposition.addMutableTrack(withMediaType: AVMediaType.audio, preferredTrackID: kCMPersistentTrackID_Invalid)! let aVideoAssetTrack: AVAssetTrack = aVideoAsset.tracks(withMediaType: AVMediaType.video)[0] let aAudioOfVideoAssetTrack: AVAssetTrack? = aVideoAsset.tracks(withMediaType: AVMediaType.audio).first let aAudioAssetTrack: AVAssetTrack = aAudioAsset.tracks(withMediaType: AVMediaType.audio)[0] // Default must have tranformation compositionAddVideo.preferredTransform = aVideoAssetTrack.preferredTransform if shouldFlipHorizontally { // Flip video horizontally var frontalTransform: CGAffineTransform = CGAffineTransform(scaleX: -1.0, y: 1.0) frontalTransform = frontalTransform.translatedBy(x: -aVideoAssetTrack.naturalSize.width, y: 0.0) frontalTransform = frontalTransform.translatedBy(x: 0.0, y: -aVideoAssetTrack.naturalSize.width) compositionAddVideo.preferredTransform = frontalTransform } mutableCompositionVideoTrack.append(compositionAddVideo) mutableCompositionAudioTrack.append(compositionAddAudio) mutableCompositionAudioOfVideoTrack.append(compositionAddAudioOfVideo) do { try mutableCompositionVideoTrack[0].insertTimeRange(CMTimeRangeMake(start: CMTime.zero, duration: aVideoAssetTrack.timeRange.duration), of: aVideoAssetTrack, at: CMTime.zero) //In my case my audio file is longer then video file so i took videoAsset duration //instead of audioAsset duration try mutableCompositionAudioTrack[0].insertTimeRange(CMTimeRangeMake(start: CMTime.zero, duration: aVideoAssetTrack.timeRange.duration), of: aAudioAssetTrack, at: CMTime.zero) // adding audio (of the video if exists) asset to the final composition if let aAudioOfVideoAssetTrack = aAudioOfVideoAssetTrack { try mutableCompositionAudioOfVideoTrack[0].insertTimeRange(CMTimeRangeMake(start: CMTime.zero, duration: aVideoAssetTrack.timeRange.duration), of: aAudioOfVideoAssetTrack, at: CMTime.zero) } } catch { print(error.localizedDescription) } // Exporting let savePathUrl: URL = URL(fileURLWithPath: NSHomeDirectory() + "/Documents/newVideo.mp4") do { // delete old video try FileManager.default.removeItem(at: savePathUrl) } catch { print(error.localizedDescription) } let assetExport: AVAssetExportSession = AVAssetExportSession(asset: mixComposition, presetName: AVAssetExportPresetHighestQuality)! assetExport.outputFileType = AVFileType.mp4 assetExport.outputURL = savePathUrl assetExport.shouldOptimizeForNetworkUse = true assetExport.exportAsynchronously { () -> Void in switch assetExport.status { case AVAssetExportSession.Status.completed: print("success") completion(nil, savePathUrl) case AVAssetExportSession.Status.failed: print("failed \(assetExport.error?.localizedDescription ?? "error nil")") completion(assetExport.error, nil) case AVAssetExportSession.Status.cancelled: print("cancelled \(assetExport.error?.localizedDescription ?? "error nil")") completion(assetExport.error, nil) default: print("complete") completion(assetExport.error, nil) } } }

再次感谢@Govind的回答！它对我帮助很大！
希望这个更新也能帮到其他人：）