Question

所以我一直在思考这个问题，我无法弄清楚正确的方法是什么。我想确定Windows是否使用Powershell脚本在特定时间输出声音。我可以确定音频驱动程序是否有错误，但我不能在我的生活中弄清楚系统是否正在播放声音。

我查看了.NET的{{1}}类，其中的三个类都与播放声音或操纵系统声音有关。

我不是要求为我编写代码，我只需要知道从哪里开始检查Windows系统当前是否正在播放声音。

我有一个声音监视器，它不断监视Node.js平台上的声音，当它失去声音时它会发给我一个文本。好吧，我也想让它通过它所连接的所有系统，看看故障所在。这就是我想看看Windows电脑是否播放声音的原因。

Answer 1

以下是一个示例C＃代码，用于确定Windows是否正在呈现任何音频流。它使用Windows Core Audio API（特别是IAudioMeterInformation interface），并且在Vista及更高版本上受支持。

public static bool IsWindowsPlayingSound()
{
    var enumerator = (IMMDeviceEnumerator)(new MMDeviceEnumerator());
    var speakers = enumerator.GetDefaultAudioEndpoint(EDataFlow.eRender, ERole.eMultimedia);
    var meter = (IAudioMeterInformation)speakers.Activate(typeof(IAudioMeterInformation).GUID, 0, IntPtr.Zero);
    var value = meter.GetPeakValue();

    // this is a bit tricky. 0 is the official "no sound" value
    // but for example, if you open a video and plays/stops with it (w/o killing the app/window/stream),
    // the value will not be zero, but something really small (around 1E-09)
    // so, depending on your context, it is up to you to decide
    // if you want to test for 0 or for a small value
    return value > 1E-08;
}

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

private enum EDataFlow
{
    eRender,
    eCapture,
    eAll,
}

private enum ERole
{
    eConsole,
    eMultimedia,
    eCommunications,
}

[InterfaceType(ComInterfaceType.InterfaceIsIUnknown), Guid("A95664D2-9614-4F35-A746-DE8DB63617E6")]
private interface IMMDeviceEnumerator
{
    void NotNeeded();
    IMMDevice GetDefaultAudioEndpoint(EDataFlow dataFlow, ERole role);
    // the rest is not defined/needed
}

[InterfaceType(ComInterfaceType.InterfaceIsIUnknown), Guid("D666063F-1587-4E43-81F1-B948E807363F")]
private interface IMMDevice
{
    [return: MarshalAs(UnmanagedType.IUnknown)]
    object Activate([MarshalAs(UnmanagedType.LPStruct)] Guid iid, int dwClsCtx, IntPtr pActivationParams);
    // the rest is not defined/needed
}

[InterfaceType(ComInterfaceType.InterfaceIsIUnknown), Guid("C02216F6-8C67-4B5B-9D00-D008E73E0064")]
private interface IAudioMeterInformation
{
    float GetPeakValue();
    // the rest is not defined/needed
}

正如我在评论中所说，我还创建了一个开源的c ++项目，一个简单的无摩擦零依赖关系控制台应用程序，可在此处获取：https://github.com/smourier/IsWindowsPlayingSound。我添加了一个应该支持32位和64位操作系统的x86版本二进制文件：https://github.com/smourier/IsWindowsPlayingSound/releases

您可以像在任何外部.exe程序中一样在PowerShell中使用它。它将返回您可以使用标准方式检索的错误级别，例如：https://blogs.msdn.microsoft.com/powershell/2006/09/15/errorlevel-equivalent/

这是等效的C ++代码：

  #include "stdafx.h" // includes <Endpointvolume.h> and <Mmdeviceapi.h>

  #define WIDEN2(x) L ## x
  #define WIDEN(x) WIDEN2(x)
  #define __WFILE__ WIDEN(__FILE__)
  #define HRCHECK(__expr) {hr=(__expr);if(FAILED(hr)){wprintf(L"FAILURE 0x%08X (%i)\n\tline: %u file: '%s'\n\texpr: '" WIDEN(#__expr) L"'\n",hr, hr, __LINE__,__WFILE__);goto cleanup;}}
  #define RELEASE(__p) {if(__p!=nullptr){__p->Release();__p=nullptr;}}

  int main(int argc, char *argv[])
  {
    BOOL playing = FALSE;
    BOOL loopmode = FALSE;
    float epsilon = 1E-07;
    float value = 0;
    HRESULT hr = S_OK;
    IMMDeviceEnumerator* pEnumerator = NULL;
    IMMDevice *pDevice = NULL;
    IAudioMeterInformation *pMeter = NULL;

    // Parse optional args
    // "loop" -> sets a loop mode for easy testing
    // <float value> -> changes epsilon
    for (int i = 1; i < argc; i++)
    {
      if (!strcmp(argv[i], "loop"))
      {
        loopmode = TRUE;
        continue;
      }

      float eps = atof(argv[i]);
      if (eps != 0.0)
      {
        epsilon = eps;
        continue;
      }
    }

    CoInitialize(NULL);
    HRCHECK(CoCreateInstance(__uuidof(MMDeviceEnumerator), NULL, CLSCTX_ALL, __uuidof(IMMDeviceEnumerator), (void**)&pEnumerator));
    HRCHECK(pEnumerator->GetDefaultAudioEndpoint(EDataFlow::eRender, ERole::eMultimedia, &pDevice));
    HRCHECK(pDevice->Activate(__uuidof(IAudioMeterInformation), CLSCTX_ALL, NULL, (void**)&pMeter));
    do
    {
      HRCHECK(pMeter->GetPeakValue(&value));
      playing = value > epsilon;
      if (!loopmode)
        break;

      printf("%.10f playing:%i\n", value, playing);
      Sleep(100);
    } while (TRUE);

  cleanup:
    RELEASE(pMeter);
    RELEASE(pDevice);
    RELEASE(pEnumerator);
    CoUninitialize();
    if (FAILED(hr))
    {
      printf("An error occurred: 0x%08X\n", hr);
      return hr;
    }

    if (playing)
    {
      printf("Windows is playing a sound.\n");
    }
    else
    {
      printf("Windows is not playing a sound.\n");
    }
    return playing;
  }

Answer 2

以下是使用Simon Mourier提供的代码的方法。

运行以下代码：

Add-Type -TypeDefinition @'
using System;
using System.Runtime.InteropServices;

namespace Foo
{
    public class Bar
    {
        public static bool IsWindowsPlayingSound()
        {
            IMMDeviceEnumerator enumerator = (IMMDeviceEnumerator)(new MMDeviceEnumerator());
            IMMDevice speakers = enumerator.GetDefaultAudioEndpoint(EDataFlow.eRender, ERole.eMultimedia);
            IAudioMeterInformation meter = (IAudioMeterInformation)speakers.Activate(typeof(IAudioMeterInformation).GUID, 0, IntPtr.Zero);
            float value = meter.GetPeakValue();

            // this is a bit tricky. 0 is the official "no sound" value
            // but for example, if you open a video and plays/stops with it (w/o killing the app/window/stream),
            // the value will not be zero, but something really small (around 1E-09)
            // so, depending on your context, it is up to you to decide
            // if you want to test for 0 or for a small value
            return value > 1E-08;
        }

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

        private enum EDataFlow
        {
            eRender,
            eCapture,
            eAll,
        }

        private enum ERole
        {
            eConsole,
            eMultimedia,
            eCommunications,
        }

        [InterfaceType(ComInterfaceType.InterfaceIsIUnknown), Guid("A95664D2-9614-4F35-A746-DE8DB63617E6")]
        private interface IMMDeviceEnumerator
        {
            void NotNeeded();
            IMMDevice GetDefaultAudioEndpoint(EDataFlow dataFlow, ERole role);
            // the rest is not defined/needed
        }

        [InterfaceType(ComInterfaceType.InterfaceIsIUnknown), Guid("D666063F-1587-4E43-81F1-B948E807363F")]
        private interface IMMDevice
        {
            [return: MarshalAs(UnmanagedType.IUnknown)]
            object Activate([MarshalAs(UnmanagedType.LPStruct)] Guid iid, int dwClsCtx, IntPtr pActivationParams);
            // the rest is not defined/needed
        }

        [InterfaceType(ComInterfaceType.InterfaceIsIUnknown), Guid("C02216F6-8C67-4B5B-9D00-D008E73E0064")]
        private interface IAudioMeterInformation
        {
            float GetPeakValue();
            // the rest is not defined/needed
        }
    }
}
'@

我替换了所有var类型，因为这似乎解决了PowerShell版本2上未编译的代码的问题。

加载后，您可以检查状态：

[Foo.Bar]::IsWindowsPlayingSound()
True or False

我在PowerShell 5.1上使用Windows 10 1703进行了测试，

但有一些警告：

this is a bit tricky. 0 is the official "no sound" value
but for example, if you open a video and plays/stops with it (w/o killing the app/window/stream),
the value will not be zero, but something really small (around 1E-09)
so, depending on your context, it is up to you to decide
if you want to test for 0 or for a small value

因此，如果您将return value > 1E-08更改为return value > 0，则会在视频暂停时生效。

Answer 3

您可以使用AudioDeviceCmdlets

撰写的Chris Hunt模块

Write-DefaultAudioDeviceValue -StreamValue看起来像你在找什么。否则你可以看一下他如何使用CoreAudioApi

来提取这些值

确定窗口当前是否正在播放声音

3 个答案: