在不停止 sound/music 的情况下从设备录制视频

Question

我正在使用 Swift 的 AVFoundation 在 iOS 中捕获视频。但是当我使用 Apple Music/Spotify 播放歌曲然后单击我的应用程序的录制按钮时，它 pauses/stops 音乐然后录制视频。我如何防止这种情况发生？

这是我的代码：

@IBAction func record_video(sender: AnyObject) {
        var initialOutputURL = NSURL(fileURLWithPath: "")

        do
        {
            initialOutputURL = try NSFileManager.defaultManager().URLForDirectory(.DocumentDirectory, inDomain: .UserDomainMask, appropriateForURL: nil, create: true).URLByAppendingPathComponent("output").URLByAppendingPathExtension("mov")
        }catch
        {
            print(error)
        }
        if !isRecording
        {

            isRecording = true
            if let outputs = captureSession.outputs as? [AVCaptureOutput] {
                for output in outputs {
                    captureSession.removeOutput(output)
                }
            }

            do
            {
                try audioSession.setCategory(AVAudioSessionCategoryAmbient)
            }
            catch
            {
                print("Can't Set Audio Session Category: \(error)")
            }
            AVAudioSessionCategoryOptions.MixWithOthers

            do
            {
                try audioSession.setMode(AVAudioSessionModeVideoRecording)
            }
            catch
            {
                print("Can't Set Audio Session Mode: \(error)")
            }
            // Start Session
            do
            {
                try audioSession.setActive(true)
            }
            catch
            {
                print("Can't Start Audio Session: \(error)")
            }


            UIView.animateWithDuration(0.5, delay: 0.0, options: [.Repeat, .Autoreverse, .AllowUserInteraction], animations: { () -> Void in
                self.record.transform = CGAffineTransformMakeScale(0.75, 0.75)
                }, completion: nil)

            let audioInputDevice = AVCaptureDevice.defaultDeviceWithMediaType(AVMediaTypeAudio)
            do
            {
                let audioInput = try AVCaptureDeviceInput(device: audioInputDevice)

                // Add Audio Input
                if captureSession.canAddInput(audioInput)
                {
                    //captureSession.addInput(audioInput)
                }
                else
                {
                    NSLog("Can't Add Audio Input")
                }

            let videoInput: AVCaptureDeviceInput
            do
            {
                videoInput = try AVCaptureDeviceInput(device: captureDevice)

                // Add Video Input
                if captureSession.canAddInput(videoInput)
                {
                    captureSession.addInput(videoInput)
                }
                else
                {
                    NSLog("ERROR: Can't add video input")
                }
            }
            catch let error
            {
                NSLog("ERROR: Getting input device: \(error)")
            }
            videoFileOutput = AVCaptureMovieFileOutput()
            captureSession.addOutput(videoFileOutput)
            captureSession.sessionPreset = AVCaptureSessionPresetHigh
            captureSession.automaticallyConfiguresApplicationAudioSession = false

            videoFileOutput?.startRecordingToOutputFileURL(initialOutputURL, recordingDelegate: self)


            }
            catch let error
            {
                NSLog("Error Getting Input Device: \(error)")
            }

        }
        else
        {
            isRecording = false

            UIView.animateWithDuration(0.5, delay: 0, options: [], animations: { () -> Void in
                self.record.transform = CGAffineTransformMakeScale(1.0, 1.0)
                }, completion: nil)
            record.layer.removeAllAnimations()
            videoFileOutput?.stopRecording()
        }



    }

注意我注释掉了 captureSession.addInput(audioInput)。如果我删除该代码，该应用程序能够录制视频，它不会 pause/stop 音乐，但视频输出没有声音。有解决办法吗？

Answer 1

可以参考这篇

的回答

我已经使用 SCRecorder 库实现了相同的功能，但也可以使用 AVCaptureSession 实现。

Answer 2

我自己设法解决了这个问题。该行：AVAudioSessionCategoryOptions.MixWithOthers 不执行任何操作。我将其移至选项： try audioSession.setCategory(AVAudioSessionCategoryPlayAndRecord, withOptions: [AVAudioSessionCategoryOptions.MixWithOthers])

成功了！

Answer 3

这是 swift 中对我有用的东西，它与杰森的回答本质上是一样的，但 swift.

将此代码添加到您的

    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?){


        add your laucher code
       let audioSession = AVAudioSession.sharedInstance()
    do {
        // Set the audio session category, mode, and options.
        try audioSession.setCategory(.playAndRecord,  options: [.mixWithOthers,.defaultToSpeaker,.allowBluetooth])
        try audioSession.setActive(true)
    } catch {
        print("Failed to set audio session category.")
    }
  }

然后在您设置捕获会话的文件中

   captureSession.automaticallyConfiguresApplicationAudioSession = false

本质上，与其他选项混音的工作原理如文档 "option that indicates whether audio from this session mixes with audio from active sessions in other audio apps" (https://developer.apple.com/documentation/avfoundation/avaudiosession/categoryoptions) 中所述，并且默认为扬声器允许在与其他选项混音时让音乐响亮。

在不停止 sound/music 的情况下从设备录制视频

Recording a Video without stopping sound/music from device

video

avfoundation

ios

swift