Added WPF (desktop) application

Audio Router WPF/App.xaml.cs

@@ -13,5 +13,16 @@ namespace Audio_Router_WPF
     /// </summary>
     public partial class App : Application
     {
+        public static App appRef;
+        // The list of audio graphs
+        public List<AudioGraphConnection> audioGraphConnections;
+        public static Windows.System.Display.DisplayRequest displayRequest = new Windows.System.Display.DisplayRequest();
+
+
+        public App()
+        {
+            appRef = this;
+            audioGraphConnections = new List<AudioGraphConnection>();
+        }
     }
 }

Audio Router WPF/Audio Router WPF.csproj

@@ -2,10 +2,16 @@
 
   <PropertyGroup>
     <OutputType>WinExe</OutputType>
-    <TargetFramework>net5.0-windows</TargetFramework>
+    <TargetFramework>net5.0-windows10.0.19041.0</TargetFramework>
     <RootNamespace>Audio_Router_WPF</RootNamespace>
     <Nullable>enable</Nullable>
     <UseWPF>true</UseWPF>
+    <SupportedOSPlatformVersion>10.0.17763.0</SupportedOSPlatformVersion>
+    <FileVersion>1.2.3.2</FileVersion>
+    <AssemblyVersion>1.2.3.2</AssemblyVersion>
+    <NeutralLanguage>en-NZ</NeutralLanguage>
+    <RepositoryUrl>https://git.software.kauripeak.co.nz/BrychanD/Audio-Router</RepositoryUrl>
+    <Copyright>(C) 2021 Brychan Dempsey</Copyright>
   </PropertyGroup>
 
 </Project>

Audio Router WPF/AudioGraphConnection.cs

@@ -0,0 +1,177 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Windows.Threading;
+using System.Threading.Tasks;
+using Windows.Media.Audio;
+using System.Windows.Controls;
+using System.Windows;
+using System.Windows.Documents;
+using System.Windows.Media;
+
+namespace Audio_Router_WPF
+{
+    public class AudioGraphConnection
+    {
+        string SourceNames { get; }
+        string TargetNames { get; }
+        int SamplesPerMS { get; }
+
+        public AudioGraph Graph { get; private set; }
+
+        AudioDeviceOutputNode TargetDevice { get; set; }
+        AudioDeviceInputNode SourceDevice { get; set; }
+
+        Dispatcher uiDispatcher { get; set; }
+
+        TextBlock latencyLabel { get; set; }
+
+        int quantaCount = 0;
+
+        public AudioGraphConnection(AudioGraph graph, AudioDeviceOutputNode targetDevice, AudioDeviceInputNode sourceDevice, Dispatcher uiDispatcher)
+        {
+            Graph = graph;
+            TargetDevice = targetDevice;
+            SourceDevice = sourceDevice;
+            this.uiDispatcher = uiDispatcher;
+            SourceNames = sourceDevice.Device.Name;
+            TargetNames = targetDevice.Device.Name;
+
+            SamplesPerMS = (int)(Graph.SamplesPerQuantum / (double)Graph.EncodingProperties.SampleRate * 1000);
+        }
+
+        /// <summary>
+        /// Creates a grid populated with UI controls containing information about this item, i.e. for rendering
+        /// </summary>
+        /// <returns></returns>
+        public Grid GetAsDisplayItem(out Button deletionButton)
+        {
+            // Create the display elements
+            Grid result = new Grid();
+            Button destroyButton = new Button()
+            {
+                Content = "Stop",
+                HorizontalAlignment = HorizontalAlignment.Right
+            };
+
+            TextBlock label = new TextBlock()
+            {
+                HorizontalAlignment = HorizontalAlignment.Left
+            };
+            latencyLabel = new TextBlock()
+            {
+                Padding = new Thickness(0, 0, 5, 0)
+            };
+            Slider volumeSlider = new Slider
+            {
+                Maximum = 5.0,
+                Minimum = 0.0,
+                Value = 1.0,
+                SmallChange = 0.1,
+                MinWidth = 250,
+                Margin = new Thickness(5, 0, 5, 0)
+            };
+
+            StackPanel rightSide = new StackPanel
+            {
+                Orientation = Orientation.Horizontal
+            };
+
+            // Set the base grid to span the full screen width available
+            result.HorizontalAlignment = HorizontalAlignment.Stretch;
+            result.Margin = new Thickness(1, 1, 1, 5);
+            // Add Column definitions
+            result.ColumnDefinitions.Add(new ColumnDefinition()); // '*' size; fits the maximum space it can, evenly
+            result.ColumnDefinitions.Add(new ColumnDefinition()   // 'auto'; automatically resizes to the total size of the children elements
+            {
+                Width = GridLength.Auto
+            });
+
+
+            Run sourceDev = new Run()
+            {
+                Text = SourceNames
+            };
+            Run arrow = new Run
+            {
+                Text = "  ",
+                FontFamily = new FontFamily("Segoe MDL2 Assets")
+            };
+            Run targetDev = new Run()
+            {
+                Text = TargetNames
+            };
+
+            // Add the text to the label
+            label.Inlines.Add(sourceDev);
+            label.Inlines.Add(arrow);
+            label.Inlines.Add(targetDev);
+
+            // Register the event 
+            destroyButton.Click += DestroyButton_Click;
+            result.Children.Add(label);
+
+            volumeSlider.ValueChanged += VolumeSlider_ValueChanged;
+
+            Graph.QuantumProcessed += Graph_QuantumProcessed;
+            rightSide.Children.Add(latencyLabel);
+            rightSide.Children.Add(volumeSlider);
+            rightSide.Children.Add(destroyButton);
+            rightSide.HorizontalAlignment = HorizontalAlignment.Right;
+            result.Children.Add(rightSide);
+            Grid.SetColumn(rightSide, 1);
+            deletionButton = destroyButton;
+            return result;
+        }
+
+        private void Graph_QuantumProcessed(AudioGraph sender, object args)
+        {
+            // updates aren't urgent, only process after some time (this is 1s, with the Windows default of 10 ms / quanta
+            if (quantaCount++ == 100)
+            {
+                string result = (Graph.LatencyInSamples / (double)Graph.SamplesPerQuantum * SamplesPerMS).ToString("0.#") + " ms";
+                if (latencyLabel is null) return;
+                uiDispatcher.Invoke(() =>
+                 {
+                     try
+                     {
+                         latencyLabel.Text = result;
+                     }
+                     catch
+                     {
+
+                     }
+                 }, DispatcherPriority.Background);
+                quantaCount = 0;
+            }
+        }
+
+        private void VolumeSlider_ValueChanged(object sender, RoutedPropertyChangedEventArgs<double> e)
+        {
+            TargetDevice.OutgoingGain = e.NewValue;
+            SourceDevice.OutgoingGain = e.NewValue;
+        }
+
+        private void DestroyButton_Click(object sender, RoutedEventArgs e)
+        {
+            latencyLabel = null;
+            Graph.QuantumProcessed -= Graph_QuantumProcessed;
+            Graph.Stop();
+            TargetDevice.Dispose();
+            SourceDevice.Dispose();
+            Graph.Dispose();
+            Graph = null;
+            TargetDevice = null;
+            SourceDevice = null;
+            uiDispatcher = null;
+            _ = App.appRef.audioGraphConnections.Remove(this);
+            GC.Collect();
+        }
+
+        public void OnHide()
+        {
+            latencyLabel = null;
+        }
+    }
+}

Audio Router WPF/MainWindow.xaml

@@ -6,7 +6,27 @@
         xmlns:local="clr-namespace:Audio_Router_WPF"
         mc:Ignorable="d"
         Title="MainWindow" Height="450" Width="800">
-    <Grid>
+    <Grid VerticalAlignment="Stretch">
+        <Grid.RowDefinitions>
+            <RowDefinition Height="Auto"/>
+            <RowDefinition/>
+        </Grid.RowDefinitions>
+        <Grid.Background>
+            <SolidColorBrush Color="#CC000000" />
+        </Grid.Background>
+        <StackPanel x:Name="SourceFlyout" Margin="20,30,20,20" Grid.RowSpan="1" VerticalAlignment="Stretch">
+            <TextBlock Text="Input Audio Device:" TextWrapping="Wrap" Margin="0,10,0,0" Foreground="White" HorizontalAlignment="Center"/>
+            <ComboBox x:Name="InputAudioComboBox" MinWidth="500" HorizontalAlignment="Center"/>
+            <TextBlock Text="Output Audio Device:" TextWrapping="Wrap" Margin="0,10,0,0" Foreground="White" HorizontalAlignment="Center"/>
+            <ComboBox x:Name="OutputAudioComboBox" MinWidth="500" HorizontalAlignment="Center"/>
+            <CheckBox x:Name="LowLatencyCheckbox" Content="Low Latency Mode (Reduces audio quality)" HorizontalAlignment="Center" Margin="0,10,0,0"/>
+            <StackPanel Orientation="Horizontal" HorizontalAlignment="Center" Margin="0,20,0,5">
+                <Button x:Name="AddAudioGraphButton" Content="Add Audio Graph" HorizontalContentAlignment="Center" Background="#54FFFFFF" Click="AddAudioGraphButton_Click"/>
+            </StackPanel>
+        </StackPanel>
+        <ScrollViewer Grid.Row="1" Margin="10,5,10,5"  Padding="0,0,10,0">
+            <StackPanel x:Name="CreatedGraphs"/>
 
+        </ScrollViewer>
     </Grid>
 </Window>

Audio Router WPF/MainWindow.xaml.cs

@@ -11,7 +11,14 @@ using System.Windows.Input;
 using System.Windows.Media;
 using System.Windows.Media.Imaging;
 using System.Windows.Navigation;
+using Windows.UI.Core;
 using System.Windows.Shapes;
+using Windows.Devices.Enumeration;
+using Windows.Media.Audio;
+using System.Windows.Threading;
+using Windows.Media.Devices;
+using Windows.Media.Render;
+using Windows.Media.Capture;
 
 namespace Audio_Router_WPF
 {
@@ -20,9 +27,152 @@ namespace Audio_Router_WPF
     /// </summary>
     public partial class MainWindow : Window
     {
+        //AudioGraph graph;
+        // The list of audio devices
+        DeviceInformationCollection sourceDevices;
+        DeviceInformationCollection targetDevices;
         public MainWindow()
         { 
             InitializeComponent();
+            _ = Task.Run(() => FindAudioSources());
         }
+
+        private async void AddAudioGraphButton_Click(object sender, RoutedEventArgs e)
+        {
+            await CreateAudioGraph();
+        }
+
+        private async Task FindAudioSources()
+        {
+            // First, clear the lists
+            Dispatcher.Invoke(() =>
+            {
+                InputAudioComboBox.Items.Clear();
+                OutputAudioComboBox.Items.Clear();
+            }, DispatcherPriority.Normal);
+            // Perform this on our spawned thread, as the operation is asynchronous-synchronous await
+            sourceDevices = await DeviceInformation.FindAllAsync(MediaDevice.GetAudioCaptureSelector());
+            targetDevices = await DeviceInformation.FindAllAsync(MediaDevice.GetAudioRenderSelector());
+
+            DeviceInformation defaultOutput = await DeviceInformation.CreateFromIdAsync(MediaDevice.GetDefaultAudioRenderId(AudioDeviceRole.Default));
+            DeviceInformation defaultInput = await DeviceInformation.CreateFromIdAsync(MediaDevice.GetDefaultAudioCaptureId(AudioDeviceRole.Default));
+
+            Dispatcher.Invoke(() =>
+            {
+                // Set the Input device
+                for (int i = 0; i < sourceDevices.Count; i++)
+                {
+                    if (sourceDevices[i].Id == defaultInput.Id)
+                    {
+                        _ = InputAudioComboBox.Items.Add(sourceDevices[i].Name + " (Default Device)");
+                        InputAudioComboBox.SelectedIndex = i;
+                    }
+                    else
+                    {
+                        _ = InputAudioComboBox.Items.Add(sourceDevices[i].Name);
+                    }
+                }
+                for (int i = 0; i < targetDevices.Count; i++)
+                {
+                    if (targetDevices[i].Id == defaultOutput.Id)
+                    {
+                        _ = OutputAudioComboBox.Items.Add(targetDevices[i].Name + " (Default Device)");
+                        OutputAudioComboBox.SelectedIndex = i;
+                    }
+                    else
+                    {
+                        _ = OutputAudioComboBox.Items.Add(targetDevices[i].Name);
+                    }
+                }
+            });
+        }
+
+
+        private async Task CreateAudioGraph()
+        {
+            App.displayRequest.RequestActive();
+            DeviceInformation outputDevice = targetDevices[OutputAudioComboBox.SelectedIndex];
+            DeviceInformation inputDevice = sourceDevices[InputAudioComboBox.SelectedIndex];
+            AudioGraphSettings settings = LowLatencyCheckbox.IsChecked == true
+                ? new AudioGraphSettings(AudioRenderCategory.Media)
+                {
+                    QuantumSizeSelectionMode = QuantumSizeSelectionMode.ClosestToDesired,
+                    DesiredSamplesPerQuantum = 10,
+                    PrimaryRenderDevice = outputDevice,
+                    DesiredRenderDeviceAudioProcessing = Windows.Media.AudioProcessing.Raw,
+                    EncodingProperties = new Windows.Media.MediaProperties.AudioEncodingProperties()
+                    {
+                        Subtype = "Float",
+                        SampleRate = 128000, // Manually set to 128 000 samples/second so that the delay is significantly reduced
+                        ChannelCount = 2,
+                        BitsPerSample = 32,
+                        Bitrate = 3072000
+                    }
+                }
+                : new AudioGraphSettings(AudioRenderCategory.Media)
+                {
+                    PrimaryRenderDevice = outputDevice
+                };
+            CreateAudioGraphResult result = await AudioGraph.CreateAsync(settings);
+            AudioGraph ag = result.Graph;
+
+            if (result.Status != AudioGraphCreationStatus.Success)
+            {
+                return;
+            }
+
+            CreateAudioDeviceInputNodeResult deviceInputNodeResult = await ag.CreateDeviceInputNodeAsync(MediaCategory.Other, ag.EncodingProperties, inputDevice);
+
+            if (deviceInputNodeResult.Status != AudioDeviceNodeCreationStatus.Success)
+            {
+                // Fail-safe, switch to using the default encoding properties
+                settings = new AudioGraphSettings(AudioRenderCategory.Media)
+                {
+                    PrimaryRenderDevice = outputDevice
+                };
+                result = await AudioGraph.CreateAsync(settings);
+                ag = result.Graph;
+
+                if (result.Status != AudioGraphCreationStatus.Success)
+                {
+                    return;
+                }
+                deviceInputNodeResult = await ag.CreateDeviceInputNodeAsync(MediaCategory.Other, ag.EncodingProperties, inputDevice);
+                if (deviceInputNodeResult.Status != AudioDeviceNodeCreationStatus.Success)
+                {
+                    return;
+                }
+            }
+
+            // Create the device output node connection
+            CreateAudioDeviceOutputNodeResult deviceOutputNodeResult = await ag.CreateDeviceOutputNodeAsync();
+            if (deviceOutputNodeResult.Status != AudioDeviceNodeCreationStatus.Success)
+            {
+                return;
+            }
+            deviceInputNodeResult.DeviceInputNode.AddOutgoingConnection(deviceOutputNodeResult.DeviceOutputNode);
+            // appMediaControls.PlaybackStatus = MediaPlaybackStatus.Playing;
+            ag.Start();
+            AudioGraphConnection graphConnection = new AudioGraphConnection(ag, deviceOutputNodeResult.DeviceOutputNode, deviceInputNodeResult.DeviceInputNode, Dispatcher);
+            App.appRef.audioGraphConnections.Add(graphConnection);
+
+            // Hold a reference to the created button; when clicked we must also ensure we remove this visual element from the grid display
+            Grid renderGrid = graphConnection.GetAsDisplayItem(out Button visualButton);
+            CreatedGraphs.Children.Add(renderGrid);
+            // Inline decl to add a second listener to the click event - will remove the grid from the display
+            void handler(object sender, RoutedEventArgs e)
+            {
+                visualButton.Click -= handler;
+                DestroyVisualElement(ref renderGrid);
+            }
+            visualButton.Click += handler;
+        }
+
+        private void DestroyVisualElement(ref Grid element)
+        {
+            CreatedGraphs.Children.Remove(element);
+            element = null;
+        }
+
     }
 }

Audio Router.sln

@@ -5,7 +5,7 @@ VisualStudioVersion = 17.0.31710.8
 MinimumVisualStudioVersion = 10.0.40219.1
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Audio Router UWP", "Audio Router UWP\Audio Router\Audio Router UWP.csproj", "{92D76120-5578-484A-BB93-24D105B48043}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Audio Router WPF", "Audio Router WPF\Audio Router WPF.csproj", "{E0BEDD27-7800-4434-BA2D-7D71964F557F}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Audio Router WPF", "Audio Router WPF\Audio Router WPF.csproj", "{E0BEDD27-7800-4434-BA2D-7D71964F557F}"
 EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution