ios - Swift 合并音视频 Swift3

Question

我有一个视频，我正在将另一个音频合并到那个视频，所以现在我有两个音频和那个视频，一个是原始声音，另一个是视频自己的声音。现在的问题是我可以为视频自己的声音设置音量，但我无法设置外部音频的音量。我用下面的代码来做同样的事情。

func mergeAV(videoUrl: URL, audioUrl: URL, shouldFlipHorizontally: Bool = false) {
    print("\(#function)")
    process_merge.startAnimating()

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

    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]

    compositionAddVideo?.preferredTransform = aVideoAssetTrack.preferredTransform

    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)

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

        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 fileManager = FileManager.default
    let documentsDirectory = fileManager.urls(for: .documentDirectory, in: .userDomainMask)[0]
    let savePathUrl = documentsDirectory.appendingPathComponent("MergeAudioVideo.mp4")

    do {
        // delete old video
        try FileManager.default.removeItem(at: savePathUrl)
    } catch {
        print(error.localizedDescription)
    }

    var videoVolume : Float = 0.0
    var audioVolume : Float = 0.0
    videoVolume = self.vol_Video.value
    audioVolume = self.vol_Audio.value

    let audioMix: AVMutableAudioMix = AVMutableAudioMix()
    var audioMixParam: [AVMutableAudioMixInputParameters] = []

    let videoParam: AVMutableAudioMixInputParameters = AVMutableAudioMixInputParameters(track: aVideoAssetTrack)
    videoParam.trackID = (compositionAddVideo?.trackID)!

    let musicParam: AVMutableAudioMixInputParameters = AVMutableAudioMixInputParameters(track: aAudioAssetTrack)
    musicParam.trackID = (compositionAddAudio?.trackID)!

    videoParam.setVolume(videoVolume, at: CMTime.zero)
    musicParam.setVolume(audioVolume, at: CMTime.zero)

    videoParam.setVolumeRamp(fromStartVolume: videoVolume, toEndVolume: videoVolume, timeRange: aVideoAssetTrack.timeRange)
    musicParam.setVolumeRamp(fromStartVolume: videoVolume, toEndVolume: audioVolume, timeRange: aAudioAssetTrack.timeRange)

    audioMixParam.append(musicParam)
    audioMixParam.append(videoParam)

    audioMix.inputParameters = [musicParam,videoParam]

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

    print("Export Action")
    assetExport.exportAsynchronously { () -> Void in
        self.process_merge.stopAnimating()

        switch assetExport.status {
        case AVAssetExportSession.Status.completed:
            print("Merge video+Audio URL : \(savePathUrl)")
            print("Export : success")
            self.showMess(strMess: "Success...\nMerge video+Audio URL: \(savePathUrl)", isAlert: false)
            break

        default:
            print("Error : unknown")
            self.showMess(strMess: "Something was wrong. Please try again.\nError: \(assetExport.error?.localizedDescription ?? "unknown")", isAlert: true)
            break
        }
    }
}

我该如何解决这个问题？请帮忙!

Answer 1

func mergeFilesWithUrl(videoUrl: URL, audioUrl: URL) {

    let mixComposition: AVMutableComposition = AVMutableComposition()

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

    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))
    mutableCompositionAudioOfVideoTrack.append(mixComposition.addMutableTrack(withMediaType: AVMediaTypeAudio, preferredTrackID: kCMPersistentTrackID_Invalid))

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

    do {
        try mutableCompositionAudioOfVideoTrack[0].insertTimeRange(CMTimeRangeMake(kCMTimeZero, aVideoAssetTrack.timeRange.duration), of: aAudioOfVideoTrack, at: kCMTimeZero)
        try mutableCompositionVideoTrack[0].insertTimeRange(CMTimeRangeMake(kCMTimeZero, aVideoAssetTrack.timeRange.duration), of: aVideoAssetTrack, at: kCMTimeZero)
        try mutableCompositionAudioTrack[0].insertTimeRange(CMTimeRangeMake(kCMTimeZero, aVideoAssetTrack.timeRange.duration), of: aAudioAssetTrack, at: 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)//CGSize(1280,720)

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

    do { // delete old video
        try FileManager.default.removeItem(at: savePathUrl as URL)
    } catch {
        print(error.localizedDescription)
    }

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

    assetExport.exportAsynchronously {
        switch assetExport.status {
        case AVAssetExportSessionStatus.completed:
            print("success")
        case AVAssetExportSessionStatus.failed:
            print("failed \(assetExport.error)")
        case AVAssetExportSessionStatus.cancelled:
            print("cancelled \(assetExport.error)")
        default:
            print("complete")
        }
    }
}