VFW(Video for Windows)函数是Windows环境下实现视频捕获的重要工具，是Windows操作系统增设的视频服务库。由于VFW函数可以方便地实现视频、音频数据流到AVI文件的存储，在Visual C++中也将VFW函数称为AVICAP窗口类函数。AVICAP窗口类为应用程序提供了一个基于访问视频采集硬件的、基于消息的接口，从而使之能访问视频和波形文件，能灵活的实现从模拟视频源采集数字视频信号，并将所捕获的视频流存储到磁盘或直接对视频缓存进行处理。-VFW (Video for Windows) function is a Windows environment, an important tool for video capture is the Windows operating system, library of additional video services. Because the function can be easily achieved VFW video and audio data stream to AVI file is stored in the Visual C++ will also function as AVICAP VFW window class function. AVICAP window class provides applications access the video capture of a hardware-based, message-based interface, so that it can access video and waveform files can be a flexible source capture analog video from a digital video signal, and the video captured stream is stored to disk or directly to the video buffer for processing.