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I am making a small application in C++ (using OpenCV) that records a video and then lets you warp it by rotating your view in x,y,z.

Right now I am just starting to test the rotation by making it rotate a small angle every iteration. Although the display of the video works fine, the writing into a file doesn't. As you can see from the code I am warping each frame using the purely rotational homography and then showing and writing the warped frame. For some reason even though the un-warped video is a few MB big, the warped video is only a few KB and it doesn't play using Ubuntu's standard video player. My best guess is that since I am warping the frame I am affecting the frame size in a way that openCV fails to save correctly. I have no idea on how to fix it though.

Any ideas?

Code:

//I already recorded the video and saved it into a file called videoName with FPS frames/sec. 
VideoCapture video(videoName);
if(!video.isOpened()) {
   std::cerr << videoName <<" could not be opened\n";
   return -1;
 }
namedWindow(videoName, CV_WINDOW_AUTOSIZE);
namedWindow("lol",CV_WINDOW_AUTOSIZE);
std::cout << video.get(CV_CAP_PROP_FPS) << std::endl;
float xTheta = 0;
float yTheta = 0;
string oVideoName = "oVideo.avi";
Size ofSize(video.get(CV_CAP_PROP_FRAME_WIDTH),video.get(CV_CAP_PROP_FRAME_HEIGHT));
VideoWriter vwriter2(oVideoName,CV_FOURCC('D','I','V','X'),FPS,ofSize,true);
if (!vwriter2.isOpened())
{
  std::cout << "ERROR: Failed to write the video" << std::endl;
  return -1;
}
while(true) {
  Mat frame;
  bool bSuccess = video.read(frame);
  if(!bSuccess || waitKey(1000/FPS) >= 0)
  {
    std::cout << "END\n";
    break;
  }
  yTheta += 0.00002;
  Mat Rx = (Mat_<float>(3,3) << 1,0,0,0,cos(xTheta),-sin(xTheta),0,sin(xTheta),cos(xTheta));
  Mat Ry = (Mat_<float>(3,3) << cos(yTheta),0,sin(yTheta),0,1,0,-sin(yTheta),0,cos(yTheta));
  Mat H = Rx * Ry;
  Mat pFrame(frame.size(),frame.type());
  warpPerspective(frame,pFrame,H,frame.size());
  imshow("lol", pFrame);
  vwriter.write(pFrame);
}
return 0;
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1 回答 1

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也许您应该阅读一下有关如何从此链接保存视频文件的信息。此外,您的代码中存在拼写错误。在上面引用的代码的第 35 行,应该是,

vwriter2.write(pFrame);

于 2013-10-23T11:49:28.300 回答