Minor improvements accross a range of components

AudioSwitcher.AudioApi.CoreAudio/CoreAudioController.cs

@@ -25,17 +25,24 @@ public CoreAudioController()
             {
                 // ReSharper disable once SuspiciousTypeConversion.Global
                 _innerEnumerator = ComObjectFactory.GetDeviceEnumerator();
+                _systemEvents = new SystemEventNotifcationClient(_innerEnumerator);
 
                 if (_innerEnumerator == null)
                     return;
 
-                _systemEvents = new SystemEventNotifcationClient(_innerEnumerator);
-
                 _systemEvents.DeviceAdded.Subscribe(x => OnDeviceAdded(x.DeviceId));
                 _systemEvents.DeviceRemoved.Subscribe(x => OnDeviceRemoved(x.DeviceId));
-            });
 
-            RefreshSystemDevices();
+                _deviceCache = new HashSet<CoreAudioDevice>();
+                IMultimediaDeviceCollection collection;
+                _innerEnumerator.EnumAudioEndpoints(EDataFlow.All, EDeviceState.All, out collection);
+
+                using (var coll = new MultimediaDeviceCollection(collection))
+                {
+                    foreach (var mDev in coll)
+                        CacheDevice(mDev);
+                }
+            });
         }
 
         internal SystemEventNotifcationClient SystemEvents => _systemEvents;
@@ -63,25 +70,20 @@ private void OnDeviceRemoved(string deviceId)
 
         protected override void Dispose(bool disposing)
         {
-            ComThread.BeginInvoke(() =>
+            if (_systemEvents != null)
             {
-                if (_systemEvents != null)
-                {
-                    _systemEvents.Dispose();
-                    _systemEvents = null;
-                }
+                _systemEvents.Dispose();
+                _systemEvents = null;
+            }
 
-                _innerEnumerator = null;
-            })
-            .ContinueWith(x =>
+            foreach (var device in _deviceCache)
             {
-                foreach (var device in _deviceCache)
-                {
-                    device.Dispose();
-                }
-                _deviceCache?.Clear();
-                _lock?.Dispose();
-            });
+                device.Dispose();
+            }
+
+            _deviceCache?.Clear();
+            _lock?.Dispose();
+            _innerEnumerator = null;
 
             base.Dispose(disposing);
 
@@ -120,22 +122,6 @@ private CoreAudioDevice GetDevice(string realId)
             }
         }
 
-        private void RefreshSystemDevices()
-        {
-            ComThread.Invoke(() =>
-            {
-                _deviceCache = new HashSet<CoreAudioDevice>();
-                IMultimediaDeviceCollection collection;
-                _innerEnumerator.EnumAudioEndpoints(EDataFlow.All, EDeviceState.All, out collection);
-
-                using (var coll = new MultimediaDeviceCollection(collection))
-                {
-                    foreach (var mDev in coll)
-                        CacheDevice(mDev);
-                }
-            });
-        }
-
         private CoreAudioDevice GetOrAddDeviceFromRealId(string deviceId)
         {
             //This pre-check here may prevent more com objects from being created

AudioSwitcher.AudioApi.CoreAudio/CoreAudioDevice.cs

@@ -224,6 +224,7 @@ protected override void Dispose(bool disposing)
         {
             if (!_isDisposed)
             {
+                _properties?.Dispose();
                 _peakValueTimerSubscription?.Dispose();
 
                 ComThread.BeginInvoke(() =>

AudioSwitcher.AudioApi.CoreAudio/Internal/AudioEndpointVolumeCallback.cs

@@ -46,43 +46,50 @@ internal AudioEndpointVolumeCallback(AudioEndpointVolume handler)
 
         public int OnNotify(IntPtr notifyData)
         {
-            //Since AUDIO_VOLUME_NOTIFICATION_DATA is dynamic in length based on the
-            //number of audio channels available we cannot just call PtrToStructure 
-            //to get all data, thats why it is split up into two steps, first the static
-            //data is marshalled into the data structure, then with some IntPtr math the
-            //remaining floats are read from memory.
-            //
-            var data =
-                (AudioVolumeNotificationDataStruct)
-                    Marshal.PtrToStructure(notifyData, typeof (AudioVolumeNotificationDataStruct));
-
-            //Determine offset in structure of the first float
-            var offset = Marshal.OffsetOf(typeof (AudioVolumeNotificationDataStruct), "ChannelVolume");
-            //Determine offset in memory of the first float
-            var firstFloatPtr = (IntPtr) ((long) notifyData + (long) offset);
-
-            //Something weird happened, better to ignore it and move on
-            if (data.Channels > 100)
-                return 0;
-
-            var voldata = new float[data.Channels];
-
-            //Read all floats from memory.
-            for (var i = 0; i < data.Channels; i++)
+            try
             {
-                voldata[i] = (float) Marshal.PtrToStructure(firstFloatPtr, typeof (float));
+                //Since AUDIO_VOLUME_NOTIFICATION_DATA is dynamic in length based on the
+                //number of audio channels available we cannot just call PtrToStructure 
+                //to get all data, thats why it is split up into two steps, first the static
+                //data is marshalled into the data structure, then with some IntPtr math the
+                //remaining floats are read from memory.
+                //
+                var data =
+                    (AudioVolumeNotificationDataStruct)
+                        Marshal.PtrToStructure(notifyData, typeof(AudioVolumeNotificationDataStruct));
+
+                //Determine offset in structure of the first float
+                var offset = Marshal.OffsetOf(typeof(AudioVolumeNotificationDataStruct), "ChannelVolume");
+                //Determine offset in memory of the first float
+                var firstFloatPtr = (IntPtr) ((long) notifyData + (long) offset);
+
+                //Something weird happened, better to ignore it and move on
+                if (data.Channels > 100)
+                    return 0;
+
+                var voldata = new float[data.Channels];
+
+                //Read all floats from memory.
+                for (var i = 0; i < data.Channels; i++)
+                {
+                    voldata[i] = (float) Marshal.PtrToStructure(firstFloatPtr, typeof(float));
+                }
+
+                //Create combined structure and Fire Event in parent class.
+                var notificationData = new AudioVolumeNotificationData(data.EventContext, data.Muted,
+                    data.MasterVolume, voldata);
+
+                var p = _handler.Target as AudioEndpointVolume;
+
+                if (_handler.IsAlive)
+                    p?.FireNotification(notificationData);
+            }
+            catch(Exception ex)
+            {
+                return ex.HResult;
             }
 
-            //Create combined structure and Fire Event in parent class.
-            var notificationData = new AudioVolumeNotificationData(data.EventContext, data.Muted,
-                data.MasterVolume, voldata);
-
-            var p = _handler.Target as AudioEndpointVolume;
-
-            if (_handler.IsAlive)
-                p?.FireNotification(notificationData);
-
-            return 0;
+            return 0; //success
         }
     }
 }

AudioSwitcher.AudioApi.CoreAudio/Internal/Interfaces/WaveFormat.cs

@@ -47,8 +47,6 @@ protected WaveFormat(SampleRate rate, BitDepth bits, SpeakerConfiguration channe
             {
                 throw new ArgumentOutOfRangeException(nameof(channelMask), "Channels must be 1 or greater");
             }
-            // minimum 16 bytes, sometimes 18 for PCM
-            waveFormatTag = WaveFormatEncoding.Pcm;
 
             sampleRate = (int)rate;
             bitsPerSample = (short)bits;

AudioSwitcher.AudioApi.CoreAudio/Internal/MultimediaDeviceCollection.cs

@@ -54,11 +54,7 @@ internal MultimediaDeviceCollection(IMultimediaDeviceCollection parent)
 
         public void Dispose()
         {
-            if (_multimediaDeviceCollection != null)
-            {
-                Marshal.FinalReleaseComObject(_multimediaDeviceCollection);
-                _multimediaDeviceCollection = null;
-            }
+            _multimediaDeviceCollection = null;
         }
 
         public IEnumerator<IMultimediaDevice> GetEnumerator()