Video Capture Software Components

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

The components in the diagram include:

Application

Any user-mode, Win32-based application that creates an AVIcap window (described in the Win32 SDK), calls the video API functions (described in the Video for Windows Development Kit), or calls the Video Compression Manager functions (also described in the Win32 SDK).

msvfw32.dll

Microsoft Video for Windows dynamic-link library. Exports the video API functions described in the Video for Windows Development Kit. Also exports the MCIWnd window class and DRAWDIB functions, described in the Win32 SDK. Additionally, this library includes the Video Compression Manager. For more information about the Video Compression Manager, see Video Compression Manager Drivers.

avicap32.dll

Dynamic-link library supporting the AVI capture window class.

winmm.dll

Dynamic-link library that exports SendDriverMessage, which calls a user-mode driver’s DriverProc function. See winmm.dll.

User-mode video capture drivers

Dynamic-link libraries that communicate with kernel-mode drivers.

VCM drivers

Dynamic-link libraries that compress or decompress video data and either return it to the caller or send it to a kernel-mode driver.

VCUser.lib

Library used as a basis for user-mode video capture drivers. For details, see Using VCUser.lib.

VCKernel.lib

Library used as a basis for kernel-mode video capture drivers. For details, see Using VCKernel.lib.

Kernel-mode video capture drivers

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