README

ℹ About

This project provides a standalone solution for creating virtual displays on a Windows host using the Parsec Virtual Display Driver (VDD), independent of the Parsec app.

The Parsec VDD enables virtual displays on Windows 10+ systems, a feature available to Parsec Teams and Warp customers. With VDD, users can add up to three virtual displays to a host machine they connect to, ideal for setups where physical monitors may be unavailable or when additional displays are beneficial.

Built by Parsec, the VDD leverages the IddCx API (Indirect Display Driver) to generate virtual displays with support for high resolutions and refresh rates, including up to 4K and 240 Hz. This capability makes it a versatile tool for gaming, streaming, or remote work, allowing users to simulate multiple screens for an enhanced, flexible visual experience.

📺 ParsecVDisplay App

ParsecVDisplay is a comprehensive virtual display manager for Parsec VDD, built with C# and WPF. The app provides an intuitive interface to manage virtual displays, showing the number of active displays and allowing users to add or remove specific virtual displays. It also supports features like changing display resolution, capturing screenshots, and more, making it a versatile tool for flexible display management.

👉 Check out Releases to download it.

🚀 Using Core API

Design notes

Parsec VDD is designed to work with Parsec client-connection sessions. When the user connects to the host, the app will start controlling the driver, it sends IO control codes and gets results. When adding a virtual display, you will get its index to be used for unplugging, the maximum number of displays could be added up to 16 per adapter. You have to ping the driver periodically to keep added displays alive, otherwise all of them will be unplugged after a second. There's no direct way to manipulate added displays, you should call Win32 Display API to change their display mode (see the ParsecVDisplay source).

flowchart LR
  A(app)
  B(vdd)

  A <--->|ioctl| B
  A ..->|ping| B

  B --- X(display1)
  B --- Y(display2)
  B --- Z(display3)

  winapi -->|manipulate| X

Using the code

For detailed instructions and usage examples, refer to the VDD_LIBRARY_USAGE.

• The core API is designed as single C/C++ header that can be added to any project, 👉 core/parsec-vdd.h
• There is also a simple demo program, 👉 core/vdd-demo.cc

Picking a driver

You have to install the driver to make them work.

All of them also work on Windows Server 2019 or higher.

You can unzip (using 7z) the driver setup above to obtain the driver files and nefconw CLI.

vdd-0.45/
  |__ nefconw.exe
  |__ driver/
    |__ mm.cat
    |__ mm.dll
    |__ mm.inf

Command line method to install the driver using nefconw (admin required):

start /wait .\nefconw.exe --remove-device-node --hardware-id Root\Parsec\VDA --class-guid "4D36E968-E325-11CE-BFC1-08002BE10318"
start /wait .\nefconw.exe --create-device-node --class-name Display --class-guid "4D36E968-E325-11CE-BFC1-08002BE10318" --hardware-id Root\Parsec\VDA
start /wait .\nefconw.exe --install-driver --inf-path ".\driver\mm.inf"

In addition, you can run the driver setup in silent mode to install it quickly.

.\parsec-vdd-0.45.0.0.exe /S

😥 Known Limitations

This list shows the known limitations of Parsec VDD.

1. HDR support

Parsec VDD does not support HDR on its displays (see the EDID below). Theoretically, you can unlock support by editing the EDID, then adding HDR metadata and setting 10-bit+ color depth. Unfortunately, you cannot flash its firmware like a physical device, or modify the registry value.

All IDDs have their own fixed EDID block inside the driver binary to initialize the monitor specs. So the solution is to modify this block in the driver DLL (mm.dll), then reinstall it with nefconw CLI (see above).

2. Custom resolutions

Before connecting, the virtual display looks in the HKLM\SOFTWARE\Parsec\vdd registry for additional preset resolutions. Currently this supports a maximum of 5 values.

HKLM\SOFTWARE\Parsec\vdd:
  - key: [0 -> 5]
    value: { width, height, hz }

To unlock this limit, you need to patch the driver DLL the same way as above, but 5 is enough for personal use.

😑 Known Bugs

This is a list of known issues when working with standalone Parsec VDD.

1. Incompatible with Parsec Privacy Mode

If you have enabled "Privacy Mode" in Parsec Host settings, please disable it and clear the connected display configurations in the following Registry path.

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\GraphicsDrivers\Connectivity

This option causes your main display to turn off when virtual displays are added, making it difficult to turn the display on and disrupting the remote desktop session.

2. // todo

🤔 Comparison with other IDDs

The table below shows a comparison with other popular Indirect Display Driver projects.

✅ - full support, 🆗 - limited support

Signed means that the driver files have a valid digital signature. H-Cursor means hardware cursor support, without it, you will get a double cursor on some remote desktop apps. Tweakable is the ability to customize display modes. Visit MSDN IddCx versions to check the minimum supported Windows version.

📘 Parsec VDD Specs

Common preset display modes:

Check out docs/PARSEC_VDD_SPECS to see full of preset display modes the driver specs.

🤝 Sponsors

🍻 Credits

• Thanks to Parsec for the driver
• The app's background was from old parsecgaming.com