$response = Invoke-WebRequest -Uri 'https://mirrors.gigenet.com/OSDN//mingw/70554/mingwrt-5.2.1-mingw32-dev.tar.xz' -ContentType 'application/octet-stream'

#Download and install from nuget.org
Find-Package -Source NuGet -Name SevenZipExtractor | Install-Package -Scope CurrentUser

#Add the SevenZip assembly to our current PowerShell session
(Get-Item (Join-Path (Split-Path (Get-Package SevenZipExtractor).Source) lib/netstandard*) |
  Sort-Object { [version] ($_.Name -replace '^netstandard') })[-1] |
    Get-ChildItem -Filter *.dll -Recurse |
      ForEach-Object { Write-Host "Adding ``$($_.Name)``"; Add-Type -LiteralPath $_.FullName }

public SevenZipExtractor(Stream archiveStream);
public SevenZipExtractor(Stream archiveStream, string password);
public SevenZipExtractor(Stream archiveStream, SevenZipFormat format);
public SevenZipExtractor(Stream archiveStream, string password, InArchiveFormat format);

# If $response.Content -is [byte[]] then it is sufficient to do 
$sevenZipStream = [System.IO.MemoryStream]::new(($r.Content))
# However, sometimes the file server does not respect the earlier ContentType specification
# In this case, we need to convert a string from encoding
if ($response.Content -isnot [byte[]])
{
    $encoding = $response.Encoding
    $bytes = $encoding.GetBytes($response.Content)
    $sevenZipStream = [System.IO.MemoryStream]::new($bytes)
}
else
{
    $sevenZipStream = [System.IO.MemoryStream]::new($response.Content)
}
$szExtractor = New-Object -TypeName SevenZipExtractor.ArchiveFile -ArgumentList @($sevenZipStream, )
$szExtractor.Extract("$env:TEMP",$False) # Instead of $env:TEMP, wherever you want the files to go

Install-Module -Name 7Zip4Powershell
Import-Module -Name 7Zip4Powershell -Global

tar -xf .\whatever.xz

[System.Reflection.Assembly]::LoadWithPartialName('System.IO.Compression')
    $IWRresult = Invoke-WebRequest -Uri "https://ffmpeg.zeranoe.com/builds/win64/dev/ffmpeg-latest-win64-dev.zip"  -SslProtocol Tls12 -Method Get
    $zipStream = New-Object System.IO.Memorystream
    $zipStream.Write($IWRresult.Content,0,$IWRresult.Content.Length)
    $zipFile = [System.IO.Compression.ZipArchive]::new($zipStream)
    #OK, what's in the archive I just downloaded?
    #Write the archive contents to the shell output
    $zipFile.Entries | Select-Object -ExcludeProperty @('Archive','ExternalAttributes') | Format-Table #I don't care about 'Archive' or 'ExternalAttributes', so I instruct suppress those
    #oh, there's my `aes.h` inside `ffmpeg-latest-win64-dev/include/libavutil/`
    $entry =  $zipFile.GetEntry('ffmpeg-latest-win64-dev/include/libavutil/aes.h')
    #now we have a streamreader, we can do all the things
    #for example, let's output the content to the screen
    $reader = [System.IO.StreamReader]::new($entry.Open())
    Write-Host $reader.ReadToEnd()

#Requires -Version 6.0
# Earlier, we saved the object to a file. Now we can read it back in.
[pscustomobject]@{ Greeting = "Hello World" } | Export-Clixml -Path $env:TEMP\helloworld.xml  # Imagine we did this earlier

# We can save this XML file to a zip file using Write-Zip and then encode the bytes as a base64 string
Write-Zip -Path "$env:TEMP\helloworld.xml" -OutputPath $env:TEMP\helloworld.zip -Level 9
$helloZipStream = [System.IO.FileStream]::new("$env:TEMP\helloworld.zip",[System.IO.FileMode]::Open)
$helloBytes = [byte[]]::new(($helloZipStream.Length))
$helloZipStream.Read($helloBytes, 0, $helloZipStream.Length)  # Will return the number of bytes read; note this
$helloZipStream.Close()
$helloZipStream.Dispose()  # Make the file available to the filesystem again
($helloBase64str = [System.Convert]::ToBase64String($helloBytes)) | Set-Clipboard  # We will paste this in the next script

# Now we want to read the object back in
if (Test-Path -Path "$env:TEMP\helloworld.xml")
{
    $helloWorld = Import-Clixml -Path "$env:TEMP\helloworld.xml"
}
else
{
    # For those who don't have the cli xml file on disk, provide them the base64 encoded zip file with the xml as content (increaces code complexity, but reduces the length of the string)
    # This is a base64 encoded zip file containing the helloworld.xml file
    $helloZip = [System.IO.Compression.ZipArchive]::new([System.IO.MemoryStream]::new([System.Convert]::FromBase64String('UEsDBC0AAAAIAJurslaXhee3//////////8OABQAaGVsbG93b3JsZC54bWwBABAAJwEAAAAAAAC9AAAAAAAAAG2OywrCMBBF94L/EPIBSSqupC2IC3VhFSO6rnW0lSaRzoj6945vUFdz5wznMvF0vUexhAar4BMZqUgZFUlxdrXHRJZEh57WWJTgclSuKpqAYUuqCE4fwom9Eupad4zpatOVabslxK1TzGE73iTSPBDDRfbDbjS1FyRwapL7fAcOPKn+kYLLiR9SMzs4Im/cCAXFevHH/L5xyl5xYj+CFVkihw0AVX4n0xH/HcQqNPUm1vbtPo1Ycy2n+8T0ClBLAQIzAC0AAAAIAJurslaXhee3//////////8OABQAAAAAAAAAAAAAAAAAAABoZWxsb3dvcmxkLnhtbAEAEAAnAQAAAAAAAL0AAAAAAAAAUEsFBgAAAAABAAEAUAAAAP0AAAAAAA=='), 0, 355))
    $helloWorld = [System.Management.Automation.PSSerializer]::Deserialize([System.IO.StreamReader]::new($dbZip.GetEntry('helloworld.xml').Open()).ReadToEnd())
}

# Now we can use the object
$helloWorld | Write-Host -ForegroundColor Cyan

[System.Reflection.Assembly]::LoadWithPartialName('System.IO.Compression')
$IWRresult=Invoke-WebRequest -Uri 'https://ffmpeg.zeranoe.com/builds/win64/static/ffmpeg-20200424-a501947-win64-static.zip' -Method Get -SslProtocol Tls12
$zipStream = New-Object System.IO.Memorystream
$zipStream.Write($IWRresult.Content,0,$IWRresult.Content.Length)
$zipFile = [System.IO.Compression.ZipArchive]::new($zipStream)
#OK, what did I just download?
#Write the contents to the shell output
$zipFile.Entries | Select-Object -ExcludeProperty @('Archive','ExternalAttributes') | Format-Table #I don't care about 'Archive' or 'ExternalAttributes', so I instruct suppress those
#I see there is 'ffmpeg-20200424-a501947-win64-static/bin/ffmpeg.exe' entry
$zipEntry = $zipFile.GetEntry('ffmpeg-20200424-a501947-win64-static/bin/ffmpeg.exe')
$binReader = [System.IO.BinaryReader]::new($zipEntry.Open())
#need external modules `PowerShellMafia/PowerSploit` to be able to run exe from memory (without writing to disk); see comments below this code block
Invoke-ReflectivePEInjection -PEBytes $binReader.ReadBytes() -ExeArgs "Arg1 Arg2 Arg3 Arg4"