volume.ps1

<#
  volume.ps1 - Get/Set IAudioEndpointVolume
  Note: Get-Volume/Set-Volume conflicts with Storage\MSFT_Volume
#>

function GetSet-Volume {
    Param(
        [Parameter(mandatory=$false)] [float] [ValidateRange(0.000,1.000)] $Value,
        [Alias("M*","U*")] [switch] $Mute
    )
    Set-StrictMode -Version 'Latest'

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

        [Guid("5CDF2C82-841E-4546-9722-0CF74078229A"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
        interface IAudioEndpointVolume {
          // f(), g(), ... unused COM method slots.
          int f(); int g(); int h(); int i();
          int SetMasterVolumeLevelScalar(float fLevel, System.Guid pguidEventContext);
          int j();
          int GetMasterVolumeLevelScalar(out float pfLevel);
          int k(); int l(); int m(); int n();
          int SetMute([MarshalAs(UnmanagedType.Bool)] bool bMute, System.Guid pguidEventContext);
          int GetMute(out bool pbMute);
        }
        [Guid("D666063F-1587-4E43-81F1-B948E807363F"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
        interface IMMDevice {
          int Activate(ref System.Guid id, int clsCtx, int activationParams, out IAudioEndpointVolume aev);
        }
        [Guid("A95664D2-9614-4F35-A746-DE8DB63617E6"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
        interface IMMDeviceEnumerator {
          int f(); // Unused
          int GetDefaultAudioEndpoint(int dataFlow, int role, out IMMDevice endpoint);
        }
        [ComImport, Guid("BCDE0395-E52F-467C-8E3D-C4579291692E")] class MMDeviceEnumeratorComObject { }

        public class Audio {
          static IAudioEndpointVolume Vol() {
            var enumerator = new MMDeviceEnumeratorComObject() as IMMDeviceEnumerator;
            IMMDevice dev = null;
            Marshal.ThrowExceptionForHR(enumerator.GetDefaultAudioEndpoint(/*eRender*/ 0, /*eMultimedia*/ 1, out dev));
            IAudioEndpointVolume epv = null;
            var epvid = typeof(IAudioEndpointVolume).GUID;
            Marshal.ThrowExceptionForHR(dev.Activate(ref epvid, /*CLSCTX_ALL*/ 23, 0, out epv));
            return epv;
          }
          public static float Volume {
            get {float v = -1; Marshal.ThrowExceptionForHR(Vol().GetMasterVolumeLevelScalar(out v)); return v;}
            set {Marshal.ThrowExceptionForHR(Vol().SetMasterVolumeLevelScalar(value, System.Guid.Empty));}
          }
          public static bool Mute {
            get { bool mute; Marshal.ThrowExceptionForHR(Vol().GetMute(out mute)); return mute; }
            set { Marshal.ThrowExceptionForHR(Vol().SetMute(value, System.Guid.Empty)); }
          }
        }
'@

    if ($Mute)
    {
        switch ([Audio]::get_Mute())
        {
            $True   { [Audio]::set_Mute($false) }
            $False  { [Audio]::set_Mute($true)  }
        }
    }

    if ($Value)
    {
        if ($Value -gt 0) {
            [Audio]::set_Mute($false)
            [Audio]::set_Volume($Value)
        } else {
            [Audio]::set_Volume($Value)
        }
    }

    Write-Output "$('Volume: ' + [Audio]::get_Volume())"
    Write-Output "$('Muted: '  + [Audio]::get_Mute())"
}

if (!($MyInvocation.InvocationName -eq '.' -or $MyInvocation.Line -eq '')) {
    GetSet-Volume @args
}