PowerShell/Scripts/record-mic.ps1

function Get-MicrophoneAudio {
<#
.SYNOPSIS
	Records audio from the microphone and saves to a file on disk
	Author: Justin Warner (@sixdub)
	License: BSD 3-Clause
	Required Dependencies: None
	Optional Dependencies: None
.DESCRIPTION
	Get-MicrophoneAudio utilizes the Windows API from winmm.dll to record audio from the microphone and saves the wave file to disk.
.OUTPUTS
	Outputs the FileInfo object pointing to the recording which has been saved to disk.
.PARAMETER Path
	The location to save the audio
.PARAMETER Length
	The length of the audio to record in seconds. Default: 30
.PARAMETER Alias
	The alias to use for the WinMM recording. Default: Random 10 Chars
.EXAMPLE
	Get-MicrophoneAudio -Path c:\windows\temp\secret.wav -Length 10 -Alias "SECRET"
Description
-----------
Records 10 seconds of audio to the path C:\windows\temp\secret.wav using WinMM alias "secret"
#>
	[OutputType([System.IO.FileInfo])]
	Param
	(
		[Parameter( Position = 0, Mandatory = $True)]
		[ValidateScript({Split-Path $_ | Test-Path})]
		[String] $Path,
		[Parameter( Position = 1, Mandatory = $False)]
		[Int] $Length = 30,
		[Parameter( Position = 2, Mandatory = $False)]
		[String] $Alias = $(-join ((65..90) + (97..122) | Get-Random -Count 10 | % {[char]$_}))

	)

	function Local:Get-DelegateType
	{
		Param
		(
			[OutputType([Type])]
			
			[Parameter( Position = 0)]
			[Type[]]
			$Parameters = (New-Object Type[](0)),
			
			[Parameter( Position = 1 )]
			[Type]
			$ReturnType = [Void]
		)

		$Domain = [AppDomain]::CurrentDomain
		$DynAssembly = New-Object System.Reflection.AssemblyName('ReflectedDelegate')
		$AssemblyBuilder = $Domain.DefineDynamicAssembly($DynAssembly, [System.Reflection.Emit.AssemblyBuilderAccess]::Run)
		$ModuleBuilder = $AssemblyBuilder.DefineDynamicModule('InMemoryModule', $false)
		$TypeBuilder = $ModuleBuilder.DefineType('MyDelegateType', 'Class, Public, Sealed, AnsiClass, AutoClass', [System.MulticastDelegate])
		$ConstructorBuilder = $TypeBuilder.DefineConstructor('RTSpecialName, HideBySig, Public', [System.Reflection.CallingConventions]::Standard, $Parameters)
		$ConstructorBuilder.SetImplementationFlags('Runtime, Managed')
		$MethodBuilder = $TypeBuilder.DefineMethod('Invoke', 'Public, HideBySig, NewSlot, Virtual', $ReturnType, $Parameters)
		$MethodBuilder.SetImplementationFlags('Runtime, Managed')
		
		Write-Output $TypeBuilder.CreateType()
	}

	function local:Get-ProcAddress
	{
		Param
		(
			[OutputType([IntPtr])]
		
			[Parameter( Position = 0, Mandatory = $True )]
			[String]
			$Module,
			
			[Parameter( Position = 1, Mandatory = $True )]
			[String]
			$Procedure
		)

		# Get a reference to System.dll in the GAC
		$SystemAssembly = [AppDomain]::CurrentDomain.GetAssemblies() |
			Where-Object { $_.GlobalAssemblyCache -And $_.Location.Split('\\')[-1].Equals('System.dll') }
		$UnsafeNativeMethods = $SystemAssembly.GetType('Microsoft.Win32.UnsafeNativeMethods')
		# Get a reference to the GetModuleHandle and GetProcAddress methods
		$GetModuleHandle = $UnsafeNativeMethods.GetMethod('GetModuleHandle')
		$GetProcAddress = $UnsafeNativeMethods.GetMethod('GetProcAddress')
		# Get a handle to the module specified
		$Kern32Handle = $GetModuleHandle.Invoke($null, @($Module))
		$tmpPtr = New-Object IntPtr
		$HandleRef = New-Object System.Runtime.InteropServices.HandleRef($tmpPtr, $Kern32Handle)
		
		# Return the address of the function
		Write-Output $GetProcAddress.Invoke($null, @([System.Runtime.InteropServices.HandleRef]$HandleRef, $Procedure))
	} 

	#Initialize and call LoadLibrary on our required DLL
	$LoadLibraryAddr = Get-ProcAddress kernel32.dll LoadLibraryA
	$LoadLibraryDelegate = Get-DelegateType @([String]) ([IntPtr])
	$LoadLibrary = [System.Runtime.InteropServices.Marshal]::GetDelegateForFunctionPointer($LoadLibraryAddr, $LoadLibraryDelegate)
	$HND = $null
	$HND = $LoadLibrary.Invoke('winmm.dll')
	if ($HND -eq $null)
	{
		throw 'Failed to aquire handle to winmm.dll'
	}

	#Initialize the function call to count devices
	$waveInGetNumDevsAddr = $null
	$waveInGetNumDevsAddr = Get-ProcAddress winmm.dll waveInGetNumDevs
	$waveInGetNumDevsDelegate = Get-DelegateType @() ([Uint32])
	if ($waveInGetNumDevsAddr -eq $null)
	{
		throw 'Failed to aquire address to WaveInGetNumDevs'
	}
	$waveInGetNumDevs = [System.Runtime.InteropServices.Marshal]::GetDelegateForFunctionPointer($waveInGetNumDevsAddr, $waveInGetNumDevsDelegate)

	#Initilize the function call to record audio
	$mciSendStringAddr = $null
	$mciSendStringAddr = Get-ProcAddress winmm.dll mciSendStringA
	$mciSendStringDelegate = Get-DelegateType @([String],[String],[UInt32],[IntPtr]) ([Uint32])
	if ($mciSendStringAddr -eq $null)
	{
		Throw 'Failed to aquire address to mciSendStringA'
	}
	$mciSendString = [System.Runtime.InteropServices.Marshal]::GetDelegateForFunctionPointer($mciSendStringAddr, $mciSendStringDelegate)

	#Initialize the ability to resolve MCI Errors
	$mciGetErrorStringAddr = $null
	$mciGetErrorStringAddr = Get-ProcAddress winmm.dll mciGetErrorStringA
	$mciGetErrorStringDelegate = Get-DelegateType @([UInt32],[Text.StringBuilder],[UInt32]) ([bool])
	if ($mciGetErrorStringAddr -eq $null)
	{
		throw 'Failed to aquire address to mciGetErrorString'
	}
	$mciGetErrorString = [System.Runtime.InteropServices.Marshal]::GetDelegateForFunctionPointer($mciGetErrorStringAddr,$mciGetErrorStringDelegate)

	$DeviceCount = $waveInGetNumDevs.Invoke()

	if ($DeviceCount -gt 0)
	{

		#Define buffer for MCI errors. https://msdn.microsoft.com/en-us/library/windows/desktop/dd757153(v=vs.85).aspx
		$errmsg = New-Object Text.StringBuilder 150

		#Open an alias
		$rtnVal = $mciSendString.Invoke("open new Type waveaudio Alias $alias",'',0,0)
		if ($rtnVal -ne 0) {$mciGetErrorString.Invoke($rtnVal,$errmsg,150); $msg=$errmsg.ToString();Throw "MCI Error ($rtnVal): $msg"}
		
		#Call recording function
		$rtnVal = $mciSendString.Invoke("record $alias", '', 0, 0)
		if ($rtnVal -ne 0) {$mciGetErrorString.Invoke($rtnVal,$errmsg,150); $msg=$errmsg.ToString();Throw "MCI Error ($rtnVal): $msg"}
		
		Start-Sleep -s $Length

		#save recorded audio to disk
		$rtnVal = $mciSendString.Invoke("save $alias `"$path`"", '', 0, 0)
		if ($rtnVal -ne 0) {$mciGetErrorString.Invoke($rtnVal,$errmsg,150); $msg=$errmsg.ToString();Throw "MCI Error ($rtnVal): $msg"}

		#terminate alias
		$rtnVal = $mciSendString.Invoke("close $alias", '', 0, 0);
		if ($rtnVal -ne 0) {$mciGetErrorString.Invoke($rtnVal,$errmsg,150); $msg=$errmsg.ToString();Throw "MCI Error ($rtnVal): $msg"}

		$OutFile = Get-ChildItem -path $path 
		Write-Output $OutFile
	}
	else
	{
		throw 'Failed to enumerate any recording devices'
	}
}