Windows XP Support for WDM Audio
Microsoft Windows XP supports the following WDM audio capabilities:
WDM version 1.20
All the features that Windows 2000 and Windows Me support (See Windows 2000 Support for WDM Audio and Windows Me Support for WDM Audio.)
AVStream filters, which extend the Kernel Streaming 1.0 system services (See AVStream Overview.)
Hardware acceleration of DirectSound capture effects (See Exposing Hardware-Accelerated Capture Effects.)
Access to the extended capabilities of a WDM audio driver through the Windows Multimedia functions
USB audio: All the features that Windows 2000 and Windows Me support, plus global effects (GFX) filtering (See GFX Filters.)
Additional support for kernel-mode Digital Rights Management (DRM), including IDrmPort and IDrmPort2 interfaces (See DRM Functions.)
Note In Windows XP, the Windows multimedia functions allow a maximum of 32 device interfaces on each of the following APIs: waveIn, waveOut, midiIn, midiOut, mixer, and aux. For more information, see Windows 2000 Device Interface Limits.