Fail to publish instead of crash when mic not available

.nanpa/audioengine-avoid-crash.kdl

@@ -0,0 +1 @@
+patch type="fix" "Avoid audio engine crash"

LiveKitClient.podspec

@@ -16,7 +16,7 @@ Pod::Spec.new do |spec|
 
   spec.source_files = "Sources/**/*"
 
-  spec.dependency("LiveKitWebRTC", "= 125.6422.19")
+  spec.dependency("LiveKitWebRTC", "= 125.6422.22")
   spec.dependency("SwiftProtobuf")
   spec.dependency("Logging")
   spec.dependency("DequeModule", "= 1.1.4")

Package.swift

@@ -18,7 +18,7 @@ let package = Package(
     ],
     dependencies: [
         // LK-Prefixed Dynamic WebRTC XCFramework
-        .package(url: "https://github.com/livekit/webrtc-xcframework.git", exact: "125.6422.19"),
+        .package(url: "https://github.com/livekit/webrtc-xcframework.git", exact: "125.6422.22"),
         .package(url: "https://github.com/apple/swift-protobuf.git", from: "1.26.0"),
         .package(url: "https://github.com/apple/swift-log.git", from: "1.5.4"),
         .package(url: "https://github.com/apple/swift-collections.git", from: "1.1.0"),

Package@swift-5.9.swift

@@ -20,7 +20,7 @@ let package = Package(
     ],
     dependencies: [
         // LK-Prefixed Dynamic WebRTC XCFramework
-        .package(url: "https://github.com/livekit/webrtc-xcframework.git", exact: "125.6422.19"),
+        .package(url: "https://github.com/livekit/webrtc-xcframework.git", exact: "125.6422.22"),
         .package(url: "https://github.com/apple/swift-protobuf.git", from: "1.26.0"),
         .package(url: "https://github.com/apple/swift-log.git", from: "1.5.4"),
         .package(url: "https://github.com/apple/swift-collections.git", from: "1.1.0"),

Sources/LiveKit/Audio/AudioDeviceModuleDelegateAdapter.swift

@@ -38,51 +38,51 @@ class AudioDeviceModuleDelegateAdapter: NSObject, LKRTCAudioDeviceModuleDelegate
 
     // Engine events
 
-    func audioDeviceModule(_: LKRTCAudioDeviceModule, didCreateEngine engine: AVAudioEngine) {
-        guard let audioManager else { return }
+    func audioDeviceModule(_: LKRTCAudioDeviceModule, didCreateEngine engine: AVAudioEngine) -> Int {
+        guard let audioManager else { return 0 }
         let entryPoint = audioManager.buildEngineObserverChain()
-        entryPoint?.engineDidCreate(engine)
+        return entryPoint?.engineDidCreate(engine) ?? 0
     }
 
-    func audioDeviceModule(_: LKRTCAudioDeviceModule, willEnableEngine engine: AVAudioEngine, isPlayoutEnabled: Bool, isRecordingEnabled: Bool) {
-        guard let audioManager else { return }
+    func audioDeviceModule(_: LKRTCAudioDeviceModule, willEnableEngine engine: AVAudioEngine, isPlayoutEnabled: Bool, isRecordingEnabled: Bool) -> Int {
+        guard let audioManager else { return 0 }
         let entryPoint = audioManager.buildEngineObserverChain()
-        entryPoint?.engineWillEnable(engine, isPlayoutEnabled: isPlayoutEnabled, isRecordingEnabled: isRecordingEnabled)
+        return entryPoint?.engineWillEnable(engine, isPlayoutEnabled: isPlayoutEnabled, isRecordingEnabled: isRecordingEnabled) ?? 0
     }
 
-    func audioDeviceModule(_: LKRTCAudioDeviceModule, willStartEngine engine: AVAudioEngine, isPlayoutEnabled: Bool, isRecordingEnabled: Bool) {
-        guard let audioManager else { return }
+    func audioDeviceModule(_: LKRTCAudioDeviceModule, willStartEngine engine: AVAudioEngine, isPlayoutEnabled: Bool, isRecordingEnabled: Bool) -> Int {
+        guard let audioManager else { return 0 }
         let entryPoint = audioManager.buildEngineObserverChain()
-        entryPoint?.engineWillStart(engine, isPlayoutEnabled: isPlayoutEnabled, isRecordingEnabled: isRecordingEnabled)
+        return entryPoint?.engineWillStart(engine, isPlayoutEnabled: isPlayoutEnabled, isRecordingEnabled: isRecordingEnabled) ?? 0
     }
 
-    func audioDeviceModule(_: LKRTCAudioDeviceModule, didStopEngine engine: AVAudioEngine, isPlayoutEnabled: Bool, isRecordingEnabled: Bool) {
-        guard let audioManager else { return }
+    func audioDeviceModule(_: LKRTCAudioDeviceModule, didStopEngine engine: AVAudioEngine, isPlayoutEnabled: Bool, isRecordingEnabled: Bool) -> Int {
+        guard let audioManager else { return 0 }
         let entryPoint = audioManager.buildEngineObserverChain()
-        entryPoint?.engineDidStop(engine, isPlayoutEnabled: isPlayoutEnabled, isRecordingEnabled: isRecordingEnabled)
+        return entryPoint?.engineDidStop(engine, isPlayoutEnabled: isPlayoutEnabled, isRecordingEnabled: isRecordingEnabled) ?? 0
     }
 
-    func audioDeviceModule(_: LKRTCAudioDeviceModule, didDisableEngine engine: AVAudioEngine, isPlayoutEnabled: Bool, isRecordingEnabled: Bool) {
-        guard let audioManager else { return }
+    func audioDeviceModule(_: LKRTCAudioDeviceModule, didDisableEngine engine: AVAudioEngine, isPlayoutEnabled: Bool, isRecordingEnabled: Bool) -> Int {
+        guard let audioManager else { return 0 }
         let entryPoint = audioManager.buildEngineObserverChain()
-        entryPoint?.engineDidDisable(engine, isPlayoutEnabled: isPlayoutEnabled, isRecordingEnabled: isRecordingEnabled)
+        return entryPoint?.engineDidDisable(engine, isPlayoutEnabled: isPlayoutEnabled, isRecordingEnabled: isRecordingEnabled) ?? 0
     }
 
-    func audioDeviceModule(_: LKRTCAudioDeviceModule, willReleaseEngine engine: AVAudioEngine) {
-        guard let audioManager else { return }
+    func audioDeviceModule(_: LKRTCAudioDeviceModule, willReleaseEngine engine: AVAudioEngine) -> Int {
+        guard let audioManager else { return 0 }
         let entryPoint = audioManager.buildEngineObserverChain()
-        entryPoint?.engineWillRelease(engine)
+        return entryPoint?.engineWillRelease(engine) ?? 0
     }
 
-    func audioDeviceModule(_: LKRTCAudioDeviceModule, engine: AVAudioEngine, configureInputFromSource src: AVAudioNode?, toDestination dst: AVAudioNode, format: AVAudioFormat, context: [AnyHashable: Any]) {
-        guard let audioManager else { return }
+    func audioDeviceModule(_: LKRTCAudioDeviceModule, engine: AVAudioEngine, configureInputFromSource src: AVAudioNode?, toDestination dst: AVAudioNode, format: AVAudioFormat, context: [AnyHashable: Any]) -> Int {
+        guard let audioManager else { return 0 }
         let entryPoint = audioManager.buildEngineObserverChain()
-        entryPoint?.engineWillConnectInput(engine, src: src, dst: dst, format: format, context: context)
+        return entryPoint?.engineWillConnectInput(engine, src: src, dst: dst, format: format, context: context) ?? 0
     }
 
-    func audioDeviceModule(_: LKRTCAudioDeviceModule, engine: AVAudioEngine, configureOutputFromSource src: AVAudioNode, toDestination dst: AVAudioNode?, format: AVAudioFormat, context: [AnyHashable: Any]) {
-        guard let audioManager else { return }
+    func audioDeviceModule(_: LKRTCAudioDeviceModule, engine: AVAudioEngine, configureOutputFromSource src: AVAudioNode, toDestination dst: AVAudioNode?, format: AVAudioFormat, context: [AnyHashable: Any]) -> Int {
+        guard let audioManager else { return 0 }
         let entryPoint = audioManager.buildEngineObserverChain()
-        entryPoint?.engineWillConnectOutput(engine, src: src, dst: dst, format: format, context: context)
+        return entryPoint?.engineWillConnectOutput(engine, src: src, dst: dst, format: format, context: context) ?? 0
     }
 }

Sources/LiveKit/Audio/AudioEngineObserver.swift

@@ -29,54 +29,54 @@ public protocol AudioEngineObserver: NextInvokable, Sendable {
     associatedtype Next = any AudioEngineObserver
     var next: (any AudioEngineObserver)? { get set }
 
-    func engineDidCreate(_ engine: AVAudioEngine)
-    func engineWillEnable(_ engine: AVAudioEngine, isPlayoutEnabled: Bool, isRecordingEnabled: Bool)
-    func engineWillStart(_ engine: AVAudioEngine, isPlayoutEnabled: Bool, isRecordingEnabled: Bool)
-    func engineDidStop(_ engine: AVAudioEngine, isPlayoutEnabled: Bool, isRecordingEnabled: Bool)
-    func engineDidDisable(_ engine: AVAudioEngine, isPlayoutEnabled: Bool, isRecordingEnabled: Bool)
-    func engineWillRelease(_ engine: AVAudioEngine)
+    func engineDidCreate(_ engine: AVAudioEngine) -> Int
+    func engineWillEnable(_ engine: AVAudioEngine, isPlayoutEnabled: Bool, isRecordingEnabled: Bool) -> Int
+    func engineWillStart(_ engine: AVAudioEngine, isPlayoutEnabled: Bool, isRecordingEnabled: Bool) -> Int
+    func engineDidStop(_ engine: AVAudioEngine, isPlayoutEnabled: Bool, isRecordingEnabled: Bool) -> Int
+    func engineDidDisable(_ engine: AVAudioEngine, isPlayoutEnabled: Bool, isRecordingEnabled: Bool) -> Int
+    func engineWillRelease(_ engine: AVAudioEngine) -> Int
 
     /// Provide custom implementation for internal AVAudioEngine's output configuration.
     /// Buffers flow from `src` to `dst`. Preferred format to connect node is provided as `format`.
     /// Return true if custom implementation is provided, otherwise default implementation will be used.
-    func engineWillConnectOutput(_ engine: AVAudioEngine, src: AVAudioNode, dst: AVAudioNode?, format: AVAudioFormat, context: [AnyHashable: Any])
+    func engineWillConnectOutput(_ engine: AVAudioEngine, src: AVAudioNode, dst: AVAudioNode?, format: AVAudioFormat, context: [AnyHashable: Any]) -> Int
     /// Provide custom implementation for internal AVAudioEngine's input configuration.
     /// Buffers flow from `src` to `dst`. Preferred format to connect node is provided as `format`.
     /// Return true if custom implementation is provided, otherwise default implementation will be used.
-    func engineWillConnectInput(_ engine: AVAudioEngine, src: AVAudioNode?, dst: AVAudioNode, format: AVAudioFormat, context: [AnyHashable: Any])
+    func engineWillConnectInput(_ engine: AVAudioEngine, src: AVAudioNode?, dst: AVAudioNode, format: AVAudioFormat, context: [AnyHashable: Any]) -> Int
 }
 
 /// Default implementation to make it optional.
 public extension AudioEngineObserver {
-    func engineDidCreate(_ engine: AVAudioEngine) {
-        next?.engineDidCreate(engine)
+    func engineDidCreate(_ engine: AVAudioEngine) -> Int {
+        next?.engineDidCreate(engine) ?? 0
     }
 
-    func engineWillEnable(_ engine: AVAudioEngine, isPlayoutEnabled: Bool, isRecordingEnabled: Bool) {
-        next?.engineWillEnable(engine, isPlayoutEnabled: isPlayoutEnabled, isRecordingEnabled: isRecordingEnabled)
+    func engineWillEnable(_ engine: AVAudioEngine, isPlayoutEnabled: Bool, isRecordingEnabled: Bool) -> Int {
+        next?.engineWillEnable(engine, isPlayoutEnabled: isPlayoutEnabled, isRecordingEnabled: isRecordingEnabled) ?? 0
     }
 
-    func engineWillStart(_ engine: AVAudioEngine, isPlayoutEnabled: Bool, isRecordingEnabled: Bool) {
-        next?.engineWillStart(engine, isPlayoutEnabled: isPlayoutEnabled, isRecordingEnabled: isRecordingEnabled)
+    func engineWillStart(_ engine: AVAudioEngine, isPlayoutEnabled: Bool, isRecordingEnabled: Bool) -> Int {
+        next?.engineWillStart(engine, isPlayoutEnabled: isPlayoutEnabled, isRecordingEnabled: isRecordingEnabled) ?? 0
     }
 
-    func engineDidStop(_ engine: AVAudioEngine, isPlayoutEnabled: Bool, isRecordingEnabled: Bool) {
-        next?.engineDidStop(engine, isPlayoutEnabled: isPlayoutEnabled, isRecordingEnabled: isRecordingEnabled)
+    func engineDidStop(_ engine: AVAudioEngine, isPlayoutEnabled: Bool, isRecordingEnabled: Bool) -> Int {
+        next?.engineDidStop(engine, isPlayoutEnabled: isPlayoutEnabled, isRecordingEnabled: isRecordingEnabled) ?? 0
     }
 
-    func engineDidDisable(_ engine: AVAudioEngine, isPlayoutEnabled: Bool, isRecordingEnabled: Bool) {
-        next?.engineDidDisable(engine, isPlayoutEnabled: isPlayoutEnabled, isRecordingEnabled: isRecordingEnabled)
+    func engineDidDisable(_ engine: AVAudioEngine, isPlayoutEnabled: Bool, isRecordingEnabled: Bool) -> Int {
+        next?.engineDidDisable(engine, isPlayoutEnabled: isPlayoutEnabled, isRecordingEnabled: isRecordingEnabled) ?? 0
     }
 
-    func engineWillRelease(_ engine: AVAudioEngine) {
-        next?.engineWillRelease(engine)
+    func engineWillRelease(_ engine: AVAudioEngine) -> Int {
+        next?.engineWillRelease(engine) ?? 0
     }
 
-    func engineWillConnectOutput(_ engine: AVAudioEngine, src: AVAudioNode, dst: AVAudioNode?, format: AVAudioFormat, context: [AnyHashable: Any]) {
-        next?.engineWillConnectOutput(engine, src: src, dst: dst, format: format, context: context)
+    func engineWillConnectOutput(_ engine: AVAudioEngine, src: AVAudioNode, dst: AVAudioNode?, format: AVAudioFormat, context: [AnyHashable: Any]) -> Int {
+        next?.engineWillConnectOutput(engine, src: src, dst: dst, format: format, context: context) ?? 0
     }
 
-    func engineWillConnectInput(_ engine: AVAudioEngine, src: AVAudioNode?, dst: AVAudioNode, format: AVAudioFormat, context: [AnyHashable: Any]) {
-        next?.engineWillConnectInput(engine, src: src, dst: dst, format: format, context: context)
+    func engineWillConnectInput(_ engine: AVAudioEngine, src: AVAudioNode?, dst: AVAudioNode, format: AVAudioFormat, context: [AnyHashable: Any]) -> Int {
+        next?.engineWillConnectInput(engine, src: src, dst: dst, format: format, context: context) ?? 0
     }
 }

Sources/LiveKit/Audio/DefaultAudioSessionObserver.swift

@@ -14,6 +14,8 @@
  * limitations under the License.
  */
 
+let kFailedToConfigureAudioSessionErrorCode = -4100
+
 #if os(iOS) || os(visionOS) || os(tvOS)
 
 import AVFoundation
@@ -56,26 +58,32 @@ public class DefaultAudioSessionObserver: AudioEngineObserver, Loggable, @unchec
         }
     }
 
-    public func engineWillEnable(_ engine: AVAudioEngine, isPlayoutEnabled: Bool, isRecordingEnabled: Bool) {
+    public func engineWillEnable(_ engine: AVAudioEngine, isPlayoutEnabled: Bool, isRecordingEnabled: Bool) -> Int {
         if AudioManager.shared._state.customConfigureFunc == nil {
             log("Configuring audio session...")
             let session = LKRTCAudioSession.sharedInstance()
             session.lockForConfiguration()
             defer { session.unlockForConfiguration() }
 
-            let config: AudioSessionConfiguration = isRecordingEnabled ? .playAndRecordSpeaker : .playback
-            do {
-                if _state.isSessionActive {
+            if _state.isSessionActive {
+                do {
                     log("AudioSession deactivating due to category switch")
                     try session.setActive(false) // Deactivate first
                     _state.mutate { $0.isSessionActive = false }
+                } catch {
+                    log("Failed to deactivate AudioSession with error: \(error)", .error)
                 }
+            }
 
+            let config: AudioSessionConfiguration = isRecordingEnabled ? .playAndRecordSpeaker : .playback
+            do {
                 log("AudioSession activating category to: \(config.category)")
                 try session.setConfiguration(config.toRTCType(), active: true)
                 _state.mutate { $0.isSessionActive = true }
             } catch {
                 log("AudioSession failed to configure with error: \(error)", .error)
+                // Pass error code to audio engine
+                return kFailedToConfigureAudioSessionErrorCode
             }
 
             log("AudioSession activationCount: \(session.activationCount), webRTCSessionCount: \(session.webRTCSessionCount)")
@@ -87,12 +95,12 @@ public class DefaultAudioSessionObserver: AudioEngineObserver, Loggable, @unchec
         }
 
         // Call next last
-        _state.next?.engineWillEnable(engine, isPlayoutEnabled: isPlayoutEnabled, isRecordingEnabled: isRecordingEnabled)
+        return _state.next?.engineWillEnable(engine, isPlayoutEnabled: isPlayoutEnabled, isRecordingEnabled: isRecordingEnabled) ?? 0
     }
 
-    public func engineDidDisable(_ engine: AVAudioEngine, isPlayoutEnabled: Bool, isRecordingEnabled: Bool) {
+    public func engineDidDisable(_ engine: AVAudioEngine, isPlayoutEnabled: Bool, isRecordingEnabled: Bool) -> Int {
         // Call next first
-        _state.next?.engineDidDisable(engine, isPlayoutEnabled: isPlayoutEnabled, isRecordingEnabled: isRecordingEnabled)
+        let nextResult = _state.next?.engineDidDisable(engine, isPlayoutEnabled: isPlayoutEnabled, isRecordingEnabled: isRecordingEnabled)
 
         _state.mutate {
             $0.isPlayoutEnabled = isPlayoutEnabled
@@ -111,7 +119,7 @@ public class DefaultAudioSessionObserver: AudioEngineObserver, Loggable, @unchec
                     log("AudioSession switching category to: \(config.category)")
                     try session.setConfiguration(config.toRTCType())
                 }
-                if !isPlayoutEnabled, !isRecordingEnabled {
+                if !isPlayoutEnabled, !isRecordingEnabled, _state.isSessionActive {
                     log("AudioSession deactivating")
                     try session.setActive(false)
                     _state.mutate { $0.isSessionActive = false }
@@ -122,6 +130,8 @@ public class DefaultAudioSessionObserver: AudioEngineObserver, Loggable, @unchec
 
             log("AudioSession activationCount: \(session.activationCount), webRTCSessionCount: \(session.webRTCSessionCount)")
         }
+
+        return nextResult ?? 0
     }
 }
 

Sources/LiveKit/Audio/DefaultMixerAudioObserver.swift

@@ -75,7 +75,7 @@ public final class DefaultMixerAudioObserver: AudioEngineObserver, Loggable {
         next = handler
     }
 
-    public func engineDidCreate(_ engine: AVAudioEngine) {
+    public func engineDidCreate(_ engine: AVAudioEngine) -> Int {
         let (appNode, appMixerNode, micNode, micMixerNode) = _state.read {
             ($0.appNode, $0.appMixerNode, $0.micNode, $0.micMixerNode)
         }
@@ -86,12 +86,12 @@ public final class DefaultMixerAudioObserver: AudioEngineObserver, Loggable {
         engine.attach(micMixerNode)
 
         // Invoke next
-        next?.engineDidCreate(engine)
+        return next?.engineDidCreate(engine) ?? 0
     }
 
-    public func engineWillRelease(_ engine: AVAudioEngine) {
+    public func engineWillRelease(_ engine: AVAudioEngine) -> Int {
         // Invoke next
-        next?.engineWillRelease(engine)
+        let nextResult = next?.engineWillRelease(engine)
 
         let (appNode, appMixerNode, micNode, micMixerNode) = _state.read {
             ($0.appNode, $0.appMixerNode, $0.micNode, $0.micMixerNode)
@@ -101,14 +101,15 @@ public final class DefaultMixerAudioObserver: AudioEngineObserver, Loggable {
         engine.detach(appMixerNode)
         engine.detach(micNode)
         engine.detach(micMixerNode)
+
+        return nextResult ?? 0
     }
 
-    public func engineWillConnectInput(_ engine: AVAudioEngine, src: AVAudioNode?, dst: AVAudioNode, format: AVAudioFormat, context: [AnyHashable: Any]) {
+    public func engineWillConnectInput(_ engine: AVAudioEngine, src: AVAudioNode?, dst: AVAudioNode, format: AVAudioFormat, context: [AnyHashable: Any]) -> Int {
         // Get the main mixer
         guard let mainMixerNode = context[kRTCAudioEngineInputMixerNodeKey] as? AVAudioMixerNode else {
             // If failed to get main mixer, call next and return.
-            next?.engineWillConnectInput(engine, src: src, dst: dst, format: format, context: context)
-            return
+            return next?.engineWillConnectInput(engine, src: src, dst: dst, format: format, context: context) ?? 0
         }
 
         // Read nodes from state lock.
@@ -140,7 +141,7 @@ public final class DefaultMixerAudioObserver: AudioEngineObserver, Loggable {
         }
 
         // Invoke next
-        next?.engineWillConnectInput(engine, src: src, dst: dst, format: format, context: context)
+        return next?.engineWillConnectInput(engine, src: src, dst: dst, format: format, context: context) ?? 0
     }
 }
 

Sources/LiveKit/Errors.swift

@@ -53,6 +53,10 @@ public enum LiveKitErrorType: Int, Sendable {
     case unableToResolveFPSRange = 703
     case capturerDimensionsNotResolved = 704
     case deviceAccessDenied = 705
+
+    // Audio
+    case audioEngine = 801
+    case audioSession = 802
 }
 
 extension LiveKitErrorType: CustomStringConvertible {
@@ -96,6 +100,10 @@ extension LiveKitErrorType: CustomStringConvertible {
             return "Unable to resolve FPS range"
         case .capturerDimensionsNotResolved:
             return "Capturer dimensions not resolved"
+        case .audioEngine:
+            return "Audio Engine Error"
+        case .audioSession:
+            return "Audio Session Error"
         default: return "Unknown"
         }
     }