Audio Software Components

The following diagram illustrates the relationship of the major Windows NT audio software components.

The components in the diagram include:

·Application

Any user-mode, Win32-based application that calls the audio API functions described in the Win32 SDK.

·winmm.dll

A dynamic-link library that exports the waveform, MIDI, mixer, and auxiliary audio functions described in the Win32 SDK.

·msacm32.dll

A dynamic-link library that contains the Audio Compression Manager (ACM). For information about the ACM and ACM drivers, see Audio Compression Manager Drivers.

·midimap.dll

The Windows NT MIDI Mapper.

·msacm32.drv

The Windows NT Wave Mapper.

·User-mode drivers

Dynamic-link libraries that communicate with kernel-mode drivers (or sometimes other user-mode drivers).

·ACM drivers

Dynamic-link libraries under the control of the ACM. See msacm32.dll, above.

·drvlib.lib

A library used as a basis for user-mode audio drivers. For more information, see Using drvlib.lib.

·Kernel-mode drivers

Kernel-mode code that communicates with the Windows NT Executive in order to access device hardware.

·soundlib.lib

A library used as a basis for kernel-mode audio drivers. For more information, see Using soundlib.lib.