Swift Merge audio and video files into one video

Question

I wrote a program in Swift.I want to merge a video with an audio file, but got this error.

\"failed Error Domain=AVFoundationErrorDomain Code=-11838 \

Answer 1

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)
        }
    }
}