ios同时录制视频和播放音频

Question

我想同时录制视频和播放音频。当开始录制视频时，预加载的音频开始播放，当停止视频录制时，音频也停止播放。

我尝试使用第三方库“SwiftyCam”（https://github.com/Awalz/SwiftyCam）录制视频，并在开始写入视频录制文件时开始以委托方法播放音频。

主要的 ViewCONtroller 代码如下：

override func viewDidAppear(_ animated: Bool) {
 super.viewDidAppear(animated)
 var temp = Data()
 let audioPath = Bundle.main.path(forResource: "ab1-FAST", ofType: "mp3")
        temp = FileManager.default.contents(atPath: (audioPath)!)!
     do {
            player = try  AVAudioPlayer(data: temp)
        }
        catch let error {

            print(error)
        }

        self.configureAudioSession()
        player!.delegate = self
        self.player!.prepareToPlay()
}

    // MARK: -
    // MARK: - SwiftyCamViewControllerDelegate method

func swiftyCam(_ swiftyCam: SwiftyCamViewController, didBeginRecordingVideo camera: SwiftyCamViewController.CameraSelection) {
  self.player?.play()
}

func swiftyCam(_ swiftyCam: SwiftyCamViewController, didFinishRecordingVideo camera: SwiftyCamViewController.CameraSelection) 
{
        if self.player != nil{
            if (self.player?.isPlaying)! {
                self.player?.stop()
            }
        }
}


@IBAction func btnStartStopClick(_ sender: UIButton) {

        sender.isSelected = !sender.isSelected
        if sender.isSelected{

            DispatchQueue.main.async {
                self.objVideoRecorderVC.startVideoRecording()
            }
        }else{
             self.objVideoRecorderVC.stopVideoRecording()

        }
  }

swiftycam 库：

/**

    Begin recording video of current session

    SwiftyCamViewControllerDelegate function SwiftyCamDidBeginRecordingVideo() will be called

    */
public func startVideoRecording() {
        guard let movieFileOutput = self.movieFileOutput else {
            return
        }

        if currentCamera == .rear && flashEnabled == true {
            enableFlash()
        }

        if currentCamera == .front && flashEnabled == true {
            flashView = UIView(frame: view.frame)
            flashView?.backgroundColor = UIColor.white
            flashView?.alpha = 0.85
            previewLayer.addSubview(flashView!)
        }

        sessionQueue.async { [unowned self] in
            if !movieFileOutput.isRecording {
                if UIDevice.current.isMultitaskingSupported {
                    self.backgroundRecordingID = UIApplication.shared.beginBackgroundTask(expirationHandler: nil)
                }

                // Update the orientation on the movie file output video connection before starting recording.
                let movieFileOutputConnection = self.movieFileOutput?.connection(withMediaType: AVMediaTypeVideo)


                //flip video output if front facing camera is selected
                if self.currentCamera == .front {
                    movieFileOutputConnection?.isVideoMirrored = true
                }

                movieFileOutputConnection?.videoOrientation = self.getVideoOrientation()

                // Start recording to a temporary file.
                let outputFileName = UUID().uuidString
                let outputFilePath = (NSTemporaryDirectory() as NSString).appendingPathComponent((outputFileName as NSString).appendingPathExtension("mov")!)


                movieFileOutput.startRecording(toOutputFileURL: URL(fileURLWithPath: outputFilePath), recordingDelegate: self)
                self.isVideoRecording = true
    DispatchQueue.main.async {
                    self.cameraDelegate?.swiftyCam(self, didBeginRecordingVideo: self.currentCamera)
                }
            }
            else {
                movieFileOutput.stopRecording()
            }
        }
    }

问题：有时开始播放音频会延迟一微秒。 当音频开始播放并在视频录制中录制声音时，一些时间同步正确，声音有一些时间延迟。

我通过将音频与原始音频合并进行检查，如下图所示存在一些延迟。问题并不总是随机延迟而不是同步。

有什么解决办法吗？ 如何同时录制视频和播放音频（单击单击按钮）开始并且没有延迟和同步问题？ 还有什么办法吗？

用于播放音频：AVAudioPlayer

用于录制视频：Swiftycam (AVCaptureSession)

Answer 1

你可以尝试几件事：

1) 在后台队列中播放音频：

dispatch_async(dispatch_get_global_queue(QOS_CLASS_BACKGROUN‌​D, 0)) {
    self.player.play()
}

2) 将viewDidAppear（包括prepareToPlay()）中的代码移动到viewDidLoad。我认为这将是一个不太有用的建议，因为播放是由用户启动的，但在 prepareToPlay() 和音频准备就绪之间存在延迟。

如果您尝试这些并且延迟仍然太多，您可能只需要使用AVAudioPlayer 以外的其他内容，例如OpenAL。