Audio Hardware - Upgrading and Repairing PCs - page 684

audio, rendering audio to non-default devices, improved power management and power consumption,
support for communications devices in the Sounds control panel, improved stream routing, better jack
detection routines, and new interfaces, among others. For details, see http://msdn.microsoft.com/en-
us/library/dd756612(v=vs.85).aspx .
Windows 8's Core Audio APIs include support for offloading audio streams to a connected hardware
device and for New UI (Metro) apps. For details, see http://msdn.microsoft.com/en-
us/library/windows/hardware/hh439707(v=vs.85).aspx .
As a consequence of the change from DirectX to Core Audio APIs in Windows Vista, some vendors
of sound cards took a long time to develop working drivers for their hardware under Windows Vista.
Because Windows 7 and Windows 8 use improved versions of the Core Audio APIs, it took much
less time for vendors to roll out working drivers for these versions of Windows.
Because of the changes to 3D audio support, 3D game development for Windows Vista also required
a new direction.
3D Gaming Audio Standards
One of the most common uses today for PC audio is 3D gaming, and 3D audio effects enhance the
feeling of “being inside the game.” 3D audio standards include 3D audio positioning and 3D audio
effects. 3D audio positioning refers to the apparent location of sounds in a 3D game, while 3D audio
effects include reverb, echoes, and other types of effects.
Until the introduction of Windows Vista, Windows games typically used the 3D audio features in
DirectX (9.0 and earlier) for 3D audio positioning and acceleration. Starting with DirectX 10
(Windows Vista), Microsoft switched to Core Audio APIs for all audio functionality. This change
meant that beginning with Windows Vista, Windows no longer supports DirectX 3D audio.
Fortunately, an open-source 3D API allows these versions of Windows (Vista, 7, and 8) to provide
accelerated 3D audio for games written for DirectX 9 and earlier versions. OpenAL was originally
developed as a joint venture between Creative Labs and the now-defunct Loki Software to help port
Windows games to Linux distros.
As the name suggests, OpenAL is an open-source 3D audio API that is available for Windows 8 and
earlier versions, Mac OS X, and Linux and is supported by many popular games and game engines.
OpenAL is supported natively on SoundBlaster Audigy, X-Fi, and Recon3D cards and runs in a
software mode on other cards.
Note
The official Creative Labs OpenAL website
( http://connect.creativelabs.com/openal/default.aspx ) provides OpenAL versions up to 1.1
only. Other vendors offering audio products based on OpenAL include Blue Ripple Sound
(commercial, available from www.blueripplesound.com ) , OpenAL Soft (open-source,
available at http://kcat.strangesoft.net/openal.html ), and Adalin (free and commercial,
available from www.adalin.com ) .
Tip
Because of the changes in 3D audio in Windows Vista and later versions, many sound cards