What is DirectX?

Windows Microsoft DirectX is a set of low-level application programming interfaces (APIs) that enables Microsoft Windows programs to include fast and powerful multimedia features. DirectX provides access to your display and audio cards, enabling your programs to offer realistic three-dimensional (3-D) graphics and immersive music and audio effects.

DirectX enables a program to determine the hardware capabilities of your computer, and then sets the program parameters to match. This makes it possible for multimedia programs to run on any Windows-based computer that contains hardware and drivers compatible with DirectX. It also ensures that multimedia programs take full advantage of your high-performance hardware.

DirectX contains a set of APIs that provide access to the advanced features of high-performance hardware, such as 3-D graphics acceleration chips and sound cards. These APIs control low-level functions, including two-dimensional (2-D) graphics acceleration; support for input devices such as joysticks, keyboards, and mice; networking for multiplayer games; and control of sound mixing and sound output. The low-level functions are supported by these components that make up DirectX:

DirectX Graphics combines the Microsoft DirectDraw and Microsoft Direct3D components of previous DirectX versions into a single API that you can use for all graphics programming. The component includes the Direct3DX utility library that simplifies many graphics programming tasks. DirectX Graphics provides a device-independent way for software programs to communicate with accelerator hardware efficiently and powerfully.

DirectX Audio combines the Microsoft DirectSound and Microsoft DirectMusic components of previous DirectX versions into a single API that you can use for all audio programming. DirectX Audio provides software developers with the ability to create immersive, dynamic soundtracks that respond to a variety of changes in the software environment, not the least of which is direct user input.

The Microsoft DirectInput API provides advanced input for games and processes input from joysticks, as well as from other related devices including the mouse, keyboard, and force-feedback game controllers.

The Microsoft DirectPlay API supports game connections over a modem, the Internet, or a local area network (LAN). DirectPlay simplifies access to communication services and provides a way for games to communicate with each other, independent of the protocol or online service. DirectPlay provides lobbying services that simplify the initialization of a multiplayer game, and supports reliable communication protocols to ensure that important game data is not lost on the network. DirectPlay also supports voice communication over the network.

The Microsoft DirectShow API provides high-quality capture and playback of multimedia files located on your computer and on Internet servers. DirectShow supports a wide variety of audio and video formats, including Advanced Streaming Format (ASF), Audio-Video Interleaved (AVI), digital video (DV), Motion Picture Experts Group (MPEG), MPEG Audio Layer-3 (MP3), Windows Media Audio/Video (WMA/WMV), and WAV files. DirectShow enables video capture, digital video disc (DVD) playback, video editing and mixing, hardware accelerated video decoding, and tuning of broadcast analog and digital television signals.

The Microsoft DirectSetup API provides simple, one-call installation of the DirectX components.