c# - 在 vb.net 中运行基于声音 VU 级别的脚本

Question

我正在设计一个应用程序来为我制作我的一款游戏。但是，我要采用的方法是在运行所需的宏组合之前，在声级 中聆听声音或尖峰。我要监视的音频是当前 PC 的音频输出，而不是麦克风或外部设备。

这个主题似乎在教程或信息上含糊不清，但据我所知，我发现了一个帖子 here这解释了使用 BuckSoft.DirectSound项目？

那么根据我找到的信息，我假设你做了类似下面的事情？

If AnalogSignalMeter1.LeftLevel > 0 Or AnalogSignalMeter1.RightLevel > 0 Then

    ' Do Something

End If

从个人角度来看，我很乐意帮助向公众阐明解决方案，因为这个主题没有得到很好的记录和回避。我对所有解决方案或建议持开放态度，但是，我的重点是 vb.net，如果需要会考虑 C#。

---

我看到的另一个选项是 CoreAudio API。我已经在多个帖子中看到此 API 用于提取当前声级的能力，但是我还没有看到读取当前 Master VU meter and fader data/Levels 的示例。

Private Function GetVol() As Integer        'Function to read current volume setting
    Dim MasterMinimum As Integer = 0
    Dim DevEnum As New MMDeviceEnumerator()
    Dim device As MMDevice = DevEnum.GetDefaultAudioEndpoint(EDataFlow.eRender, ERole.eMultimedia)
    Dim Vol As Integer = 0

    With device.AudioEndpointVolume
        Vol = CInt(.MasterVolumeLevelScalar * 100)
        If Vol < MasterMinimum Then
            Vol = MasterMinimum / 100.0F
        End If
    End With
    Return Vol
End Function

我要收集的数据:

如下所示，我不希望收集物理声级 %，而是希望在 VU 级别从 0 飙升时运行操作。这意味着如果我播放视频或声音文件，应用程序将听到来自当前工作站的声音并执行所需的操作。

下面将是我计划如何使用或收集潜在客户数据的粗略示例。在 vb.net 中使用计时器，我可以有一个语句始终在 "VUSoundLevels" 中寻找变化(不是真正的语句)并在发生变化/输入时运行脚本。

Private Sub Timer1_Tick()

    If VUSoundLevels > 0 Then

        ' Run Code & Exit Loop

    End IF

End Sub

Answer 1

这是一个使用 Windows Core Audio Library 的 C# 解决方案

此 API 具有 Session 的概念(这有点对应于您在 Volume Mixer 中看到的内容)。因此，我提供了一个 AudioSession 包装类，它可以为您提供有关 Windows 中所有当前 session 的各种信息，包括 session 进程 ID 以及可能的名称、显示名称、图标等详细信息。

此类还有一个 GetChannelsPeakValues() 方法，它使用 IAudioMeterInformation interface获得每个音频 channel 的峰值。

这是一个 C# 控制台应用程序示例(但 AudioSession 类支持任何 UI 技术)，在运行时，将显示 chrome 浏览器 实例(运行一些视频或来自浏览器的声音和数字应该开始移动)。如果您没有 chrome，请使用您选择的其他进程。

class Program
{
    static void Main(string[] args)
    {
        // Here, I'm just monitoring chrome, one of the possible sessions.
        // If you want the whole speakers peak values, use the AudioSession.GetSpeakersChannelsPeakValues() method
        foreach (var session in AudioSession.EnumerateAll())
        {
            if (session.Process?.ProcessName == "chrome")
            {
                do
                {
                    var values = session.GetChannelsPeakValues();
                    if (values.Length == 0)
                        continue;

                    Console.WriteLine(string.Join(" ", values.Select(v => v.ToString("00%"))));
                }
                while (true);
            }
            session.Dispose();
        }
    }
}

下面是支持的 C# 代码:

public class AudioSession : IDisposable
{
    private readonly Lazy<Icon> _icon;
    private readonly Lazy<Process> _process;
    private readonly IAudioSessionControl2 _control;

    public AudioSession(IAudioSessionControl2 control)
    {
        _control = control;
        control.GetState(out var state);
        State = state;
        control.GetGroupingParam(out var guid);
        GroupingParam = guid;
        IconPath = GetString(control.GetIconPath);
        DisplayName = GetString(control.GetDisplayName);
        _icon = new Lazy<Icon>(GetIcon, true);
        _process = new Lazy<Process>(() => Process.GetProcessById(ProcessId), true);
        Id = GetString(control.GetSessionIdentifier);
        InstanceId = GetString(control.GetSessionInstanceIdentifier);
        control.GetProcessId(out var pid);
        ProcessId = pid;
        IsSystemSounds = control.IsSystemSoundsSession() == 0;
    }

    public AudioSessionState State { get; }
    public string IconPath { get; }
    public string DisplayName { get; }
    public Guid GroupingParam { get; }
    public Icon Icon => _icon.Value;
    public string Id { get; }
    public string InstanceId { get; }
    public int ProcessId { get; }
    public Process Process => _process.Value;
    public bool IsSystemSounds { get; }

    public float[] GetChannelsPeakValues()
    {
        var meter = (IAudioMeterInformation)_control;
        meter.GetMeteringChannelCount(out var channelCount);
        var values = new float[channelCount];
        meter.GetChannelsPeakValues(channelCount, values);
        return values;
    }

    private delegate int GetStringFn(out IntPtr ptr);
    private static string GetString(GetStringFn fn)
    {
        fn(out var ptr);
        if (ptr == IntPtr.Zero)
            return null;

        try
        {
            var s = Marshal.PtrToStringUni(ptr);
            if (!string.IsNullOrWhiteSpace(s) && s.StartsWith("@"))
            {
                var sb = new StringBuilder(256);
                if (SHLoadIndirectString(s, sb, sb.Capacity, IntPtr.Zero) == 0)
                {
                    s = sb.ToString();
                }
            }
            return s;
        }
        finally
        {
            Marshal.FreeCoTaskMem(ptr);
        }
    }

    private Icon GetIcon()
    {
        if (string.IsNullOrWhiteSpace(IconPath))
            return null;

        var index = ParseIconLocationPath(IconPath, out var path);
        // note this may only work if the OS bitness is the same as this process bitness
        var hIcon = ExtractIcon(IntPtr.Zero, path, index);
        return hIcon == IntPtr.Zero ? null : Icon.FromHandle(hIcon);
    }

    public override string ToString() => DisplayName;
    public void Dispose() => _icon.Value?.Dispose();

    public static float[] GetSpeakersChannelsPeakValues()
    {
        // get the speakers (1st render + multimedia) device
        var deviceEnumerator = (IMMDeviceEnumerator)(new MMDeviceEnumerator());
        deviceEnumerator.GetDefaultAudioEndpoint(EDataFlow.eRender, ERole.eMultimedia, out IMMDevice speakers);
        if (speakers == null)
            return new float[0];

        // get meter information
        speakers.Activate(typeof(IAudioMeterInformation).GUID, 0, IntPtr.Zero, out object o);
        var meter = (IAudioMeterInformation)o;
        if (meter == null)
            return new float[0];

        meter.GetMeteringChannelCount(out var count);
        if (count == 0)
            return new float[0];

        var values = new float[count];
        meter.GetChannelsPeakValues(count, values);
        return values;
    }

    public static IEnumerable<AudioSession> EnumerateAll()
    {
        // get the speakers (1st render + multimedia) device
        var deviceEnumerator = (IMMDeviceEnumerator)(new MMDeviceEnumerator());
        deviceEnumerator.GetDefaultAudioEndpoint(EDataFlow.eRender, ERole.eMultimedia, out IMMDevice speakers);
        if (speakers == null)
            yield break;

        // activate the session manager, we need the enumerator
        speakers.Activate(typeof(IAudioSessionManager2).GUID, 0, IntPtr.Zero, out object o);
        var sessionManager = (IAudioSessionManager2)o;
        if (sessionManager == null)
            yield break;

        // enumerate sessions for on this device
        sessionManager.GetSessionEnumerator(out IAudioSessionEnumerator sessionEnumerator);
        sessionEnumerator.GetCount(out int count);

        for (int i = 0; i < count; i++)
        {
            sessionEnumerator.GetSession(i, out var sessionControl);
            if (sessionControl != null)
            {
                var meter = sessionControl as IAudioMeterInformation;
                yield return new AudioSession(sessionControl);
            }
        }
    }

    [DllImport("shlwapi", CharSet = CharSet.Unicode)]
    private extern static int SHLoadIndirectString(string pszSource, StringBuilder pszOutBuf, int cchOutBuf, IntPtr ppvReserved);

    [DllImport("shlwapi", CharSet = CharSet.Unicode)]
    private static extern int PathParseIconLocation(string pszIconFile);

    [DllImport("shell32", CharSet = CharSet.Unicode)]
    private static extern IntPtr ExtractIcon(IntPtr ptr, string pszExeFileName, int nIconIndex);

    private static int ParseIconLocationPath(string location, out string path)
    {
        if (location == null)
            throw new ArgumentNullException(nameof(location));

        path = string.Copy(location);
        int index = PathParseIconLocation(path);
        int pos = path.LastIndexOf('\0');
        if (pos >= 0)
        {
            path = path.Substring(0, pos);
        }

        if (path.StartsWith("@"))
        {
            path = path.Substring(1);
        }
        return index;
    }
}

[ComImport]
[Guid("BCDE0395-E52F-467C-8E3D-C4579291692E")]
public class MMDeviceEnumerator
{
}

public enum EDataFlow
{
    eRender,
    eCapture,
    eAll,
    EDataFlow_enum_count
}

public enum ERole
{
    eConsole,
    eMultimedia,
    eCommunications,
    ERole_enum_count
}

[Guid("a95664d2-9614-4f35-a746-de8db63617e6"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
public partial interface IMMDeviceEnumerator
{
    [PreserveSig]
    int EnumAudioEndpoints(EDataFlow dataFlow, uint dwStateMask, out IntPtr ppDevices);

    [PreserveSig]
    int GetDefaultAudioEndpoint(EDataFlow dataFlow, ERole role, out IMMDevice ppEndpoint);

    [PreserveSig]
    int GetDevice([MarshalAs(UnmanagedType.LPWStr)] string pwstrId, out IMMDevice ppDevice);

    [PreserveSig]
    int RegisterEndpointNotificationCallback(IntPtr pClient);

    [PreserveSig]
    int UnregisterEndpointNotificationCallback(IntPtr pClient);
}

[Guid("d666063f-1587-4e43-81f1-b948e807363f"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
public partial interface IMMDevice
{
    [PreserveSig]
    int Activate([MarshalAs(UnmanagedType.LPStruct)] Guid iid, uint dwClsCtx, [In, Out] IntPtr pActivationParams, [MarshalAs(UnmanagedType.IUnknown)] out object ppInterface);

    [PreserveSig]
    int OpenPropertyStore(uint stgmAccess, out IntPtr ppProperties);

    [PreserveSig]
    int GetId(out IntPtr ppstrId);

    [PreserveSig]
    int GetState(out uint pdwState);
}

[Guid("C02216F6-8C67-4B5B-9D00-D008E73E0064"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
public interface IAudioMeterInformation
{
    [PreserveSig]
    int GetPeakValue(out float pfPeak);

    [PreserveSig]
    int GetMeteringChannelCount(out int pnChannelCount);

    [PreserveSig]
    int GetChannelsPeakValues(int u32ChannelCount, [Out, MarshalAs(UnmanagedType.LPArray, SizeParamIndex = 0)] float[] afPeakValues);

    [PreserveSig]
    int QueryHardwareSupport(out int pdwHardwareSupportMask);
}

[Guid("77aa99a0-1bd6-484f-8bc7-2c654c9a9b6f"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
public partial interface IAudioSessionManager2
{
    // IAudioSessionManager
    [PreserveSig]
    int GetAudioSessionControl(IntPtr AudioSessionGuid, uint StreamFlags, out IAudioSessionControl2 SessionControl);

    [PreserveSig]
    int GetSimpleAudioVolume(IntPtr AudioSessionGuid, uint StreamFlags, out IntPtr AudioVolume);

    // IAudioSessionManager2
    [PreserveSig]
    int GetSessionEnumerator(out IAudioSessionEnumerator SessionEnum);

    [PreserveSig]
    int RegisterSessionNotification(IntPtr SessionNotification);

    [PreserveSig]
    int UnregisterSessionNotification(IntPtr SessionNotification);

    [PreserveSig]
    int RegisterDuckNotification([MarshalAs(UnmanagedType.LPWStr)] string sessionID, IntPtr duckNotification);

    [PreserveSig]
    int UnregisterDuckNotification(IntPtr duckNotification);
}

[Guid("E2F5BB11-0570-40CA-ACDD-3AA01277DEE8"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
public interface IAudioSessionEnumerator
{
    [PreserveSig]
    int GetCount(out int SessionCount);

    [PreserveSig]
    int GetSession(int SessionCount, out IAudioSessionControl2 Session);
}

public enum AudioSessionState
{
    AudioSessionStateInactive = 0,
    AudioSessionStateActive = 1,
    AudioSessionStateExpired = 2,
}

[Guid("bfb7ff88-7239-4fc9-8fa2-07c950be9c6d"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
public partial interface IAudioSessionControl2
{
    // IAudioSessionControl
    [PreserveSig]
    int GetState(out AudioSessionState pRetVal);

    [PreserveSig]
    int GetDisplayName(out IntPtr pRetVal);

    [PreserveSig]
    int SetDisplayName([MarshalAs(UnmanagedType.LPWStr)] string Value, [MarshalAs(UnmanagedType.LPStruct)] Guid EventContext);

    [PreserveSig]
    int GetIconPath(out IntPtr pRetVal);

    [PreserveSig]
    int SetIconPath([MarshalAs(UnmanagedType.LPWStr)] string Value, [MarshalAs(UnmanagedType.LPStruct)] Guid EventContext);

    [PreserveSig]
    int GetGroupingParam(out Guid pRetVal);

    [PreserveSig]
    int SetGroupingParam([MarshalAs(UnmanagedType.LPStruct)] Guid Override, [MarshalAs(UnmanagedType.LPStruct)] Guid EventContext);

    [PreserveSig]
    int RegisterAudioSessionNotification(IntPtr NewNotifications);

    [PreserveSig]
    int UnregisterAudioSessionNotification(IntPtr NewNotifications);

    // IAudioSessionControl2
    [PreserveSig]
    int GetSessionIdentifier(out IntPtr pRetVal);

    [PreserveSig]
    int GetSessionInstanceIdentifier(out IntPtr pRetVal);

    [PreserveSig]
    int GetProcessId(out int pRetVal);

    [PreserveSig]
    int IsSystemSoundsSession();

    [PreserveSig]
    int SetDuckingPreference(bool optOut);
}