I am developing a new UWP app which should monitor sound and fire a event for each sudden sound blow (something like gun fire or clap).
- It needs to enable default Audio Input and monitor live audio.
- Set audio sensitivity for identifying environment noise and recognizing clap/gun-fire
- When there is a high frequency sound like a clap/gun-fire sound (Ideally it should be like configured frequency like +/-40 then it is a gun-fire/clap) then it should call a event.
No need to save Audio
I tried to implement this
SoundMonitoringPage:
public sealed partial class MyPage : Page
{
private async void Page_Loaded(object sender, RoutedEventArgs e)
{
string deviceId = Windows.Media.Devices.MediaDevice.GetDefaultAudioCaptureId(Windows.Media.Devices.AudioDeviceRole.Communications);
gameChatAudioStateMonitor = AudioStateMonitor.CreateForCaptureMonitoringWithCategoryAndDeviceId(MediaCategory.GameChat, deviceId);
gameChatAudioStateMonitor.SoundLevelChanged += GameChatSoundLevelChanged;
//other logic
}
}
Sound Level Change:
private void GameChatSoundLevelChanged(AudioStateMonitor sender, object args)
{
switch (sender.SoundLevel)
{
case SoundLevel.Full:
LevelChangeEvent();
break;
case SoundLevel.Muted:
LevelChangeEvent();
break;
case SoundLevel.Low:
// Audio capture should never be "ducked", only muted or full volume.
Debug.WriteLine("Unexpected audio state change.");
break;
}
}
ENV: windows 10 (v1809) IDE: VS 2017
Not sure if this is the right approach. This is not enabling audio and not hitting the level change event.
I see other options in WinForms & NAudio tutorial here. Probably with Sampling frequency I can check events... Doesn't have must tutorial on using NAudio with UWP to plot the graph and identify the frequency.
Update:
Followed suggestion from @Rob Caplan - MSFT, here is what I ended up with
IMemoryBufferByteAccess.cs
// We are initializing a COM interface for use within the namespace
// This interface allows access to memory at the byte level which we need to populate audio data that is generated
[ComImport]
[Guid("5B0D3235-4DBA-4D44-865E-8F1D0E4FD04D")]
[InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
unsafe interface IMemoryBufferByteAccess
{
void GetBuffer(out byte* buffer, out uint capacity);
}
GunFireMonitorPage.xaml.cs
public sealed partial class GunFireMonitorPage : Page
{
private MainPage _rootPage;
public static GunFireMonitorPage Current;
private AudioGraph _graph;
private AudioDeviceOutputNode _deviceOutputNode;
private AudioFrameInputNode _frameInputNode;
public double Theta;
public DrivePage()
{
InitializeComponent();
Current = this;
}
protected override async void OnNavigatedTo(NavigationEventArgs e)
{
_rootPage = MainPage.Current;
await CreateAudioGraph();
}
protected override void OnNavigatedFrom(NavigationEventArgs e)
{
_graph?.Dispose();
}
private void Page_Loaded(object sender, RoutedEventArgs e)
{
}
private unsafe AudioFrame GenerateAudioData(uint samples)
{
// Buffer size is (number of samples) * (size of each sample)
// We choose to generate single channel (mono) audio. For multi-channel, multiply by number of channels
uint bufferSize = samples * sizeof(float);
AudioFrame audioFrame = new AudioFrame(bufferSize);
using (AudioBuffer buffer = audioFrame.LockBuffer(AudioBufferAccessMode.Write))
using (IMemoryBufferReference reference = buffer.CreateReference())
{
// Get the buffer from the AudioFrame
// ReSharper disable once SuspiciousTypeConversion.Global
// ReSharper disable once UnusedVariable
((IMemoryBufferByteAccess) reference).GetBuffer(out var dataInBytes, out var capacityInBytes);
// Cast to float since the data we are generating is float
var dataInFloat = (float*)dataInBytes;
float freq = 1000; // choosing to generate frequency of 1kHz
float amplitude = 0.3f;
int sampleRate = (int)_graph.EncodingProperties.SampleRate;
double sampleIncrement = (freq * (Math.PI * 2)) / sampleRate;
// Generate a 1kHz sine wave and populate the values in the memory buffer
for (int i = 0; i < samples; i++)
{
double sinValue = amplitude * Math.Sin(Theta);
dataInFloat[i] = (float)sinValue;
Theta += sampleIncrement;
}
}
return audioFrame;
}
private void node_QuantumStarted(AudioFrameInputNode sender, FrameInputNodeQuantumStartedEventArgs args)
{
// GenerateAudioData can provide PCM audio data by directly synthesizing it or reading from a file.
// Need to know how many samples are required. In this case, the node is running at the same rate as the rest of the graph
// For minimum latency, only provide the required amount of samples. Extra samples will introduce additional latency.
uint numSamplesNeeded = (uint)args.RequiredSamples;
if (numSamplesNeeded != 0)
{
AudioFrame audioData = GenerateAudioData(numSamplesNeeded);
_frameInputNode.AddFrame(audioData);
}
}
private void Button_Click(object sender, RoutedEventArgs e)
{
if (generateButton.Content != null && generateButton.Content.Equals("Generate Audio"))
{
_frameInputNode.Start();
generateButton.Content = "Stop";
audioPipe.Fill = new SolidColorBrush(Colors.Blue);
}
else if (generateButton.Content != null && generateButton.Content.Equals("Stop"))
{
_frameInputNode.Stop();
generateButton.Content = "Generate Audio";
audioPipe.Fill = new SolidColorBrush(Color.FromArgb(255, 49, 49, 49));
}
}
private async Task CreateAudioGraph()
{
// Create an AudioGraph with default settings
AudioGraphSettings settings = new AudioGraphSettings(AudioRenderCategory.Media);
CreateAudioGraphResult result = await AudioGraph.CreateAsync(settings);
if (result.Status != AudioGraphCreationStatus.Success)
{
// Cannot create graph
_rootPage.NotifyUser($"AudioGraph Creation Error because {result.Status.ToString()}", NotifyType.ErrorMessage);
return;
}
_graph = result.Graph;
// Create a device output node
CreateAudioDeviceOutputNodeResult deviceOutputNodeResult = await _graph.CreateDeviceOutputNodeAsync();
if (deviceOutputNodeResult.Status != AudioDeviceNodeCreationStatus.Success)
{
// Cannot create device output node
_rootPage.NotifyUser(
$"Audio Device Output unavailable because {deviceOutputNodeResult.Status.ToString()}", NotifyType.ErrorMessage);
speakerContainer.Background = new SolidColorBrush(Colors.Red);
}
_deviceOutputNode = deviceOutputNodeResult.DeviceOutputNode;
_rootPage.NotifyUser("Device Output Node successfully created", NotifyType.StatusMessage);
speakerContainer.Background = new SolidColorBrush(Colors.Green);
// Create the FrameInputNode at the same format as the graph, except explicitly set mono.
AudioEncodingProperties nodeEncodingProperties = _graph.EncodingProperties;
nodeEncodingProperties.ChannelCount = 1;
_frameInputNode = _graph.CreateFrameInputNode(nodeEncodingProperties);
_frameInputNode.AddOutgoingConnection(_deviceOutputNode);
frameContainer.Background = new SolidColorBrush(Colors.Green);
// Initialize the Frame Input Node in the stopped state
_frameInputNode.Stop();
// Hook up an event handler so we can start generating samples when needed
// This event is triggered when the node is required to provide data
_frameInputNode.QuantumStarted += node_QuantumStarted;
// Start the graph since we will only start/stop the frame input node
_graph.Start();
}
}
GunFireMonitorPage.xaml
<Page
x:Class="SmartPileInspector.xLite.GunFireMonitorPage"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d" Loaded="Page_Loaded"
HorizontalAlignment="Center"
Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">
<ScrollViewer HorizontalAlignment="Center">
<StackPanel HorizontalAlignment="Center">
<!-- more page content -->
<Grid HorizontalAlignment="Center">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*"/>
<ColumnDefinition Width="*"/>
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition Height="55"></RowDefinition>
</Grid.RowDefinitions>
</Grid>
<AppBarButton x:Name="generateButton" Content="Generate Audio" Click="Button_Click" MinWidth="120" MinHeight="45" Margin="0,50,0,0"/>
<Border x:Name="frameContainer" BorderThickness="0" Background="#4A4A4A" MinWidth="120" MinHeight="45" Margin="0,20,0,0">
<TextBlock x:Name="frame" Text="Frame Input" VerticalAlignment="Center" HorizontalAlignment="Center" />
</Border>
<StackPanel>
<Rectangle x:Name="audioPipe" Margin="0,20,0,0" Height="10" MinWidth="160" Fill="#313131