The Oracle VM VirtualBox Guest Additions contain experimental hardware 2D video acceleration support for Windows guests.
With this feature, if an application such as a video player inside your Windows VM uses 2D video overlays to play a movie clip, then Oracle VM VirtualBox will attempt to use your host's video acceleration hardware instead of performing overlay stretching and color conversion in software, which would be slow. This currently works for Windows, Linux and macOS host platforms, provided that your host operating system can make use of 2D video acceleration in the first place.
Hardware 2D video acceleration currently has the following preconditions:
Only available for Windows guests, running Windows XP or later.
Guest Additions must be installed.
Because 2D support is still experimental at this time, it is
disabled by default and must be manually
enabled in the VM settings. See
Technically, Oracle VM VirtualBox implements this by exposing video overlay DirectDraw capabilities in the Guest Additions video driver. The driver sends all overlay commands to the host through a special communication tunnel implemented by Oracle VM VirtualBox. On the host side, OpenGL is then used to implement color space transformation and scaling.