从视频流获取图像

 1 #include <visp/vpDisplayGDI.h>
 2 #include <visp/vpDisplayOpenCV.h>
 3 #include <visp/vpDisplayX.h>
 4 #include <visp/vpTime.h>//允许使用其下的计时函数
 5 #include <visp/vpVideoReader.h>//允许读取视频流
 6 int main(int argc, char** argv)
 7 {
 8 #if defined(VISP_HAVE_OPENCV) && (VISP_HAVE_OPENCV_VERSION >= 0x020100) || defined(VISP_HAVE_FFMPEG)
 9   try {
10     std::string videoname = "video.mpg";
11     for (int i=0; i<argc; i++) {
12       if (std::string(argv[i]) == "--name")
13         videoname = std::string(argv[i+1]);
14       else if (std::string(argv[i]) == "--help") {
15         std::cout << "\nUsage: " << argv[0] << " [--name <video name>] [--help]\n" << std::endl;
16         return 0;
17       }
18     }
19     vpImage<unsigned char> I;
20     vpVideoReader g;//创建一个视频读取对象
21     g.setFileName(videoname);//设置视频的文件名
22     g.open(I);//初始化帧读取工具
23     std::cout << "video name: " << videoname << std::endl;
24     std::cout << "video framerate: " << g.getFramerate() << "Hz" << std::endl;
25     std::cout << "video dimension: " << I.getWidth() << " " << I.getHeight() << std::endl;
26 #ifdef VISP_HAVE_X11
27     vpDisplayX d(I);
28 #elif defined(VISP_HAVE_GDI)
29     vpDisplayGDI d(I);
30 #elif defined(VISP_HAVE_OPENCV)
31     vpDisplayOpenCV d(I);
32 #else
33     std::cout << "No image viewer is available..." << std::endl;
34 #endif
35     vpDisplay::setTitle(I, "Video reader");
36     while (! g.end() ) {
37       double t = vpTime::measureTimeMs();
38       g.acquire(I);
39       vpDisplay::display(I);
40       vpDisplay::flush(I);
41       if (vpDisplay::getClick(I, false)) break;
42       vpTime::wait(t, 1000. / g.getFramerate());
43     }
44   }
45   catch(vpException e) {
46     std::cout << e.getMessage() << std::endl;
47   }
48 #else
49   (void)argc;
50   (void)argv;
51   std::cout << "Install OpenCV or ffmpeg and rebuild ViSP to use this example." << std::endl;
52 #endif
53 }