演示保存一幅BMP文件到指定目录。 利用CGSnapShot抓取一帧图像到内存，然后直接从内存读取图像数据，保存数据到BMP文件。图像的大小由视频输出窗口和视频格式确定。-demonstration preserve a BMP file to the specified directory. CGSnapShot crawls using an image to memory, then read directly from the image data memory, preservat

vc++MFC逐帧读取视频文件,保存所读帧为BMP图像文件,vc++ MFC read video files frame by frame, to preserve the time-frame to BMP image files