Fix the bug which did not allow the connection to go down when switching to another destination when the previous destination was in listen mode. Fix the problem with supporting all input types on my iMac. I have added code which converts from the audio format of the input to the preferred audio format of the speech recognizer.

ListenerGS/GSConnection.swift

@@ -20,6 +20,7 @@ enum GSConnectionState {
     case connected
     case listening
     case stoplistening
+    case deleting
 }
 
 extension GSConnectionState: CustomStringConvertible
@@ -36,6 +37,8 @@ extension GSConnectionState: CustomStringConvertible
             return "listening"
         case .stoplistening:
             return "stop listening"
+        case .deleting:
+            return "deleting"
         }
     }
 }
@@ -95,6 +98,9 @@ class GSConnection : ObservableObject {
             
         case .stoplistening:
             legalTransition = ((oldState == .connected) || (oldState == .listening))
+        
+        case .deleting:
+            legalTransition = true
         }
         
         if (!legalTransition) {
@@ -182,6 +188,7 @@ class GSConnection : ObservableObject {
     }
     
     deinit {
+        changeState(newState:.deleting)
         disconnect()
     }
     
@@ -197,7 +204,10 @@ class GSConnection : ObservableObject {
         
         waitForWriteQueue()
         waitForReadQueue()
-        self.changeState(newState:.disconnected)
+        
+        if (state != .deleting) {
+            changeState(newState:.disconnected)
+        }
     }
     
     func stopListening() {
@@ -230,7 +240,8 @@ class GSConnection : ObservableObject {
     func listen(speechForwarder: SpeechForwarderProtocol) {
         textHeard = ""
         lastSent = ""
-        writeQueue.addOperation {
+        writeQueue.addOperation { [weak self] in
+            guard let self = self else { return }
             if (!self.sendListenMsg(isListening: true)) {
                 self.errorOccurred(title: "Write Error", message: "Unable to send data to the GS")
                 return

ListenerGS/GSView.swift

@@ -56,7 +56,7 @@ struct GSView: View {
                     .disabled(true)
                     .buttonStyle(GSButtonStyle())
                     
-                case .connected, .listening, .stoplistening:
+                case .connected, .listening, .stoplistening, .deleting:
                     Button("\(Image(systemName: "desktopcomputer.trianglebadge.exclamationmark"))  Disconnect from \(ipAddress)") {
                         connection.disconnect()
                     }
@@ -66,7 +66,7 @@ struct GSView: View {
                 
                 switch (connection.state)
                 {
-                case .disconnected, .stoplistening, .connecting:
+                case .disconnected, .stoplistening, .connecting, .deleting:
                     Button("\(Image(systemName: "ear.and.waveform"))  Listen and Send Text") {
                     }
                     .disabled(true)

ListenerGS/Info.plist

@@ -19,7 +19,7 @@
 	<key>CFBundleShortVersionString</key>
 	<string>1.0</string>
 	<key>CFBundleVersion</key>
-	<string>645</string>
+	<string>759</string>
 	<key>LSApplicationCategoryType</key>
 	<string>public.app-category.utilities</string>
 	<key>LSRequiresIPhoneOS</key>

ListenerGS/SpeechForwarder.swift

@@ -21,6 +21,8 @@ class SpeechForwarder : SpeechForwarderProtocol {
     
     private let logger = Logger()
     
+    private let audioQueue = DispatchQueue.global()
+    
     func startListening(connection : GSConnection) -> Bool {
         SFSpeechRecognizer.requestAuthorization { authStatus in
             OperationQueue.main.addOperation {
@@ -71,18 +73,42 @@ class SpeechForwarder : SpeechForwarderProtocol {
         try audioSession.setActive(true, options: .notifyOthersOnDeactivation)
         let inputNode = audioEngine.inputNode
         
-        // Configure the microphone input.
-        let recordingFormat = inputNode.outputFormat(forBus: 0)
-        inputNode.installTap(onBus: 0, bufferSize: 1024, format: recordingFormat) { (buffer: AVAudioPCMBuffer, when: AVAudioTime) in
-            self.recognitionRequest?.append(buffer)
-        }
-
         // Create and configure the speech recognition request.
         recognitionRequest = SFSpeechAudioBufferRecognitionRequest()
         guard let recognitionRequest = recognitionRequest else { fatalError("Unable to create a SFSpeechAudioBufferRecognitionRequest object") }
         recognitionRequest.shouldReportPartialResults = true
         recognitionRequest.requiresOnDeviceRecognition = false
         
+        // Configure the microphone input.
+        let inputFormat = inputNode.outputFormat(forBus: 0)
+        let speechFormat = recognitionRequest.nativeAudioFormat
+        logger.debug("Recording format \(inputFormat), speech format \(speechFormat)")
+        var formatConverter: AVAudioConverter?
+        if (!inputFormat.isEqual(speechFormat)) {
+            formatConverter = AVAudioConverter(from:inputFormat, to: speechFormat)
+            formatConverter?.downmix = true
+        }
+        inputNode.installTap(onBus: 0, bufferSize: 1024, format: inputFormat) { (buffer: AVAudioPCMBuffer, when: AVAudioTime) in
+            guard let formatConverter = formatConverter else {
+                self.recognitionRequest?.append(buffer)
+                return
+            }
+            // self.recognitionRequest?.append(buffer)
+            let pcmBuffer = AVAudioPCMBuffer(pcmFormat: speechFormat, frameCapacity: AVAudioFrameCount(Double(buffer.frameLength) * speechFormat.sampleRate / inputFormat.sampleRate))
+            var error: NSError? = nil
+            
+            let inputBlock: AVAudioConverterInputBlock = {inNumPackets, outStatus in
+                outStatus.pointee = AVAudioConverterInputStatus.haveData
+                return buffer
+            }
+            
+            formatConverter.convert(to: pcmBuffer!, error: &error, withInputFrom: inputBlock)
+            
+            if error == nil {
+                self.recognitionRequest?.append(pcmBuffer!)
+            }
+        }
+        
         // Create a recognition task for the speech recognition session.
         // Keep a reference to the task so that it can be canceled.
         recognitionTask = speechRecognizer.recognitionTask(with: recognitionRequest) { [weak connection] result, error in

ListenerGSTests/ListenerGSTests.swift

@@ -364,7 +364,6 @@ class ListenerGSTests: XCTestCase {
         XCTAssert(server.getDisconnect())
     }
     
-    /* This test hangs at the getDisconnect() line at the end.  Something is holding a connection reference.
     func testDestructWhileListening() throws {
         let server = GSServerMock()
         
@@ -392,8 +391,9 @@ class ListenerGSTests: XCTestCase {
             XCTAssert(!speechForwarder.isListening)
             
             connection.listen(speechForwarder: speechForwarder)
-            XCTAssert(server.getListenState(isListening: true))
+            connection.waitForWriteQueue()
             connection.waitForMain()
+            XCTAssert(server.getListenState(isListening: true))
             
             XCTAssert(speechForwarder.isListening)
             XCTAssertEqual(connection.state, .listening)
@@ -403,7 +403,6 @@ class ListenerGSTests: XCTestCase {
         
         XCTAssert(server.getDisconnect())
     }
-     */
 
     /*
     func testPerformanceExample() throws {