Error when Audio Input is in use by another app (#111)

* Remove Audio Device if it failed to configure

* Add `audio-in-use-by-other-app` error

* Try removing on interruption

* Format code

* Make error more clear

ios/CameraError.swift

@@ -154,6 +154,7 @@ enum FormatError {
 enum SessionError {
   case cameraNotReady
   case audioSessionSetupFailed(reason: String)
+  case audioInUseByOtherApp
 
   // MARK: Internal
 
@@ -163,6 +164,8 @@ enum SessionError {
       return "camera-not-ready"
     case .audioSessionSetupFailed:
       return "audio-session-setup-failed"
+    case .audioInUseByOtherApp:
+      return "audio-in-use-by-other-app"
     }
   }
 
@@ -172,6 +175,8 @@ enum SessionError {
       return "The Camera is not ready yet! Wait for the onInitialized() callback!"
     case let .audioSessionSetupFailed(reason):
       return "The audio session failed to setup! \(reason)"
+    case .audioInUseByOtherApp:
+      return "The audio session is already in use by another app with higher priority!"
     }
   }
 }

ios/CameraView+AVAudioSession.swift

@@ -19,7 +19,7 @@ extension CameraView {
   final func configureAudioSession() {
     let start = DispatchTime.now()
     do {
-      setAutomaticallyConfiguresAudioSession(false)
+      try addAudioInput()
       let audioSession = AVAudioSession.sharedInstance()
       if audioSession.category != .playAndRecord {
         // allow background music playback
@@ -30,25 +30,57 @@ extension CameraView {
       // activate current audio session because camera is active
       try audioSession.setActive(true)
     } catch let error as NSError {
+      switch error.code {
+      case 561_017_449:
+        self.invokeOnError(.session(.audioInUseByOtherApp), cause: error)
+      default:
         self.invokeOnError(.session(.audioSessionSetupFailed(reason: error.description)), cause: error)
-      setAutomaticallyConfiguresAudioSession(true)
+      }
+      self.removeAudioInput()
     }
     let end = DispatchTime.now()
     let nanoTime = end.uptimeNanoseconds - start.uptimeNanoseconds
     ReactLogger.log(level: .info, message: "Configured Audio session in \(Double(nanoTime) / 1_000_000)ms!")
   }
 
-  private final func setAutomaticallyConfiguresAudioSession(_ automaticallyConfiguresAudioSession: Bool) {
-    if captureSession.automaticallyConfiguresApplicationAudioSession != automaticallyConfiguresAudioSession {
+  /**
+   Configures the CaptureSession and adds the audio device if it has not already been added yet.
+   */
+  private final func addAudioInput() throws {
+    if audioDeviceInput != nil {
+      // we already added the audio device, don't add it again
+      return
+    }
+    removeAudioInput()
     captureSession.beginConfiguration()
-      captureSession.automaticallyConfiguresApplicationAudioSession = automaticallyConfiguresAudioSession
+    guard let audioDevice = AVCaptureDevice.default(for: .audio) else {
+      throw CameraError.device(.microphoneUnavailable)
+    }
+    audioDeviceInput = try AVCaptureDeviceInput(device: audioDevice)
+    guard captureSession.canAddInput(audioDeviceInput!) else {
+      throw CameraError.parameter(.unsupportedInput(inputDescriptor: "audio-input"))
+    }
+    captureSession.addInput(audioDeviceInput!)
+    captureSession.automaticallyConfiguresApplicationAudioSession = true
     captureSession.commitConfiguration()
   }
+
+  /**
+   Configures the CaptureSession and removes the audio device if it has been added before.
+   */
+  private final func removeAudioInput() {
+    guard let audioInput = audioDeviceInput else {
+      return
+    }
+    captureSession.beginConfiguration()
+    captureSession.removeInput(audioInput)
+    audioDeviceInput = nil
+    captureSession.commitConfiguration()
   }
 
   @objc
   func audioSessionInterrupted(notification: Notification) {
-    ReactLogger.log(level: .error, message: "The Audio Session was interrupted!")
+    ReactLogger.log(level: .error, message: "Audio Session Interruption Notification!")
     guard let userInfo = notification.userInfo,
           let typeValue = userInfo[AVAudioSessionInterruptionTypeKey] as? UInt,
           let type = AVAudioSession.InterruptionType(rawValue: typeValue) else {
@@ -56,13 +88,15 @@ extension CameraView {
     }
     switch type {
     case .began:
-      // TODO: Should we also disable the camera here? I think it will throw a runtime error
-      // disable audio session
-      try? AVAudioSession.sharedInstance().setActive(false)
+      // Something interrupted our Audio Session, stop recording audio.
+      ReactLogger.log(level: .error, message: "The Audio Session was interrupted!")
+      removeAudioInput()
     case .ended:
+      ReactLogger.log(level: .error, message: "The Audio Session interruption has ended.")
       guard let optionsValue = userInfo[AVAudioSessionInterruptionOptionKey] as? UInt else { return }
       let options = AVAudioSession.InterruptionOptions(rawValue: optionsValue)
       if options.contains(.shouldResume) {
+        ReactLogger.log(level: .error, message: "Resuming interrupted Audio Session...")
         // restart audio session because interruption is over
         configureAudioSession()
       } else {

ios/CameraView+AVCaptureSession.swift

@@ -73,24 +73,6 @@ extension CameraView {
       return invokeOnError(.device(.invalid))
     }
 
-    // Microphone (Audio Input)
-    do {
-      if let audioDeviceInput = self.audioDeviceInput {
-        captureSession.removeInput(audioDeviceInput)
-      }
-      guard let audioDevice = AVCaptureDevice.default(for: .audio) else {
-        return invokeOnError(.device(.microphoneUnavailable))
-      }
-
-      audioDeviceInput = try AVCaptureDeviceInput(device: audioDevice)
-      guard captureSession.canAddInput(audioDeviceInput!) else {
-        return invokeOnError(.parameter(.unsupportedInput(inputDescriptor: "audio-input")))
-      }
-      captureSession.addInput(audioDeviceInput!)
-    } catch {
-      return invokeOnError(.device(.invalid))
-    }
-
     // OUTPUTS
     if let photoOutput = self.photoOutput {
       captureSession.removeOutput(photoOutput)

src/CameraError.ts

@@ -20,7 +20,7 @@ export type FormatError =
   | 'format/invalid-low-light-boost'
   | 'format/invalid-format'
   | 'format/invalid-preset';
-export type SessionError = 'session/camera-not-ready' | 'session/audio-session-setup-failed';
+export type SessionError = 'session/camera-not-ready' | 'session/audio-session-setup-failed' | 'session/audio-in-use-by-other-app';
 export type CaptureError =
   | 'capture/invalid-photo-format'
   | 'capture/encoder-error'