这是从这里扩展问题Using UWP monitor live audio and detect gun-fire/clap sound
由于Dernis我终于得到了代码工作监控实时音频和触发事件时，分贝数超过一定的范围内。
当我们在办公室运行/关闭/无声区这完美的作品。
但是，当我把应用开放之路，会有交通声音，风的声音，人们谈论的声音和其他的噪音和吹事件不能正确识别。
就从哪里开始任何帮助，将不胜感激。
的OnNavigatedTo
protected override async void OnNavigatedTo(NavigationEventArgs e)
{
//other logic
await CreateInputDeviceNodeAsync(_deviceId);
}
CreateInputDeviceNodeAsync
public async Task<bool> CreateInputDeviceNodeAsync(string deviceId)
{
Console.WriteLine("Creating AudioGraphs");
// Create an AudioGraph with default settings
AudioGraphSettings graphSettings = new AudioGraphSettings(AudioRenderCategory.Media)
{
EncodingProperties = new AudioEncodingProperties
{
Subtype = "Float",
SampleRate = 48000,
ChannelCount = 2,
BitsPerSample = 32,
Bitrate = 3072000
}
};
CreateAudioGraphResult audioGraphResult = await AudioGraph.CreateAsync(graphSettings);
if (audioGraphResult.Status != AudioGraphCreationStatus.Success)
{
_rootPage.NotifyUser("Cannot create graph", NotifyType.ErrorMessage);
return false;
}
_audioGraph = audioGraphResult.Graph;
AudioGraphSettings audioGraphSettings =
new AudioGraphSettings(AudioRenderCategory.GameChat)
{
EncodingProperties = AudioEncodingProperties.CreatePcm(48000, 2, 32),
DesiredSamplesPerQuantum = 990,
QuantumSizeSelectionMode = QuantumSizeSelectionMode.ClosestToDesired
};
_frameOutputNode = _audioGraph.CreateFrameOutputNode(_audioGraph.EncodingProperties);
_quantum = 0;
_audioGraph.QuantumStarted += Graph_QuantumStarted;
LoudNoise += BlowDetected;
DeviceInformation selectedDevice = null;
if (!string.IsNullOrWhiteSpace(_deviceId))
selectedDevice = await DeviceInformation.CreateFromIdAsync(_deviceId);
if (selectedDevice == null)
{
string device = Windows.Media.Devices.MediaDevice.GetDefaultAudioCaptureId(
Windows.Media.Devices.AudioDeviceRole.Default);
if (!string.IsNullOrWhiteSpace(device))
selectedDevice = await DeviceInformation.CreateFromIdAsync(device);
else
{
_rootPage.NotifyUser($"Could not select Audio Device {device}", NotifyType.ErrorMessage);
return false;
}
}
CreateAudioDeviceInputNodeResult result =
await _audioGraph.CreateDeviceInputNodeAsync(MediaCategory.Media, audioGraphSettings.EncodingProperties,
selectedDevice);
if (result.Status != AudioDeviceNodeCreationStatus.Success)
{
_rootPage.NotifyUser("Cannot create device output node", NotifyType.ErrorMessage);
return false;
}
_selectedMicrophone = selectedDevice.Name;
_deviceInputNode = result.DeviceInputNode;
_deviceInputNode.AddOutgoingConnection(_frameOutputNode);
_frameOutputNode.Start();
_audioGraph.Start();
return true;
}
Graph_QuantumStarted
private void Graph_QuantumStarted(AudioGraph sender, object args)
{
if (++_quantum % 2 != 0) return;
AudioFrame frame = _frameOutputNode.GetFrame();
float[] dataInFloats;
using (AudioBuffer buffer = frame.LockBuffer(AudioBufferAccessMode.Write))
using (IMemoryBufferReference reference = buffer.CreateReference())
unsafe
{
// Get the buffer from the AudioFrame
// ReSharper disable once SuspiciousTypeConversion.Global
((IMemoryBufferByteAccess) reference).GetBuffer(out byte* dataInBytes,
out var capacityInBytes);
var dataInFloat = (float*) dataInBytes;
dataInFloats = new float[capacityInBytes / sizeof(float)];
for (var i = 0; i < capacityInBytes / sizeof(float); i++)
{
dataInFloats[i] = dataInFloat[i];
}
}
double decibels = dataInFloats.Aggregate<float, double>(0f, (current, sample) => current + Math.Abs(sample));
decibels = 20 * Math.Log10(decibels / dataInFloats.Length);
_decibelList.Add(decibels);
if (double.IsInfinity(decibels) || decibels < _threshold) return;//-45
if (_watch != null && _watch.Elapsed <= TimeSpan.FromSeconds(1)) return;
LoudNoise?.Invoke(this, decibels);
_watch = Stopwatch.StartNew();
}
这仅仅是统计数字。你要真正有它的功能（也许让用户通过保持和释放按钮决定）可能之前收集的数据的至少50帧（1秒）。然后，你可能会想，以确定的分贝数通常在。我能想到的3种方法可以做到这一点。
private void Graph_QuantumStarted(AudioGraph sender, object args)
{
...
double decibels = dataInFloats.Aggregate<float, double>(0f, (current, sample) => current + Math.Abs(sample)); // I dislike the fact that the decibels variable is initially inaccurate, but it's your codebase.
decibels = 20 * Math.Log10(decibels / dataInFloats.Length);
if (scanning) // class variable (bool), you can set it from the UI thread like this
{
_decibelList.Add(decibels); // I assume you made this a class variable
}
else if (decibels == Double.NaN)
{
// Code by case below
}
else if (decibels > _sensitivity) //_sensitivity is a class variable(double), initialized to Double.NaN
{
LoudNoise?.Invoke(this, true); // Calling events is a wee bit expensive, you probably want to handle the sensitivity before Invoking it, I'm also going to do it like that to make this demo simpler
}
}
maxDecibels + Math.Abs(maxDecibels* 0.2)（分贝可能是负的，因此ABS）。double maxDecibels = _decibelList.OrderByDescending(x => x)[0];
_sensitivity = maxDecibels + Math.Abs(maxDecibels* 0.2);
sensitivity = _decibelList.OrderByDescending(x => x)[24]; // If you do a variable time you can just take Count/4 - 1 as the index
int greatestChange, changeIndex = 0;
double p = Double.NaN; // Previous
for (int i = 0; i < _decibelList.Count(); i++)
{
if (p != Double.Nan)
{
change = Math.Abs(_decibelList[i] - p);
if (Math.Abs(change > greatestChange)
{
greatestChange = change;
changeIndex = i;
}
}
p = _decibelList[i];
}
int i = changeIndex;
p = Double.NaN; // reused
double c= Double.NaN; // Current
do
{
p = c != Double.NaN ? c : _decibelList[i];
c = _decibelList[++i];
} while (c < p);
_sensitivity = ((3 * c) + _decibelList[changeIndex]) / 4;