尝试使用Qt和OpenCV从高清网络摄像头获得1080p的实时feed，只能获得480p

我试图使用Qt和OpenCV获得全高清处理，目前我只能获得480p，正如您可以在代码中看到的，我已经获得了框架的宽度和高度。我还尝试设置使用cvSize(1920 x 1080)的大小，但它不会改变分辨率。

非常感谢您的帮助!

int main(int argc, char *argv[])
{
  QApplication a(argc, argv);
  VideoCapture cap(1); //capture webcam
  if (!cap.isOpened()) //if not successful then exit
  {
    qDebug() << "Cannot open webcam";
    return -1;
  }
  namedWindow("Camera feed", CV_WINDOW_AUTOSIZE); //create window
  double dWidth = cap.get(CV_CAP_PROP_FRAME_WIDTH); //get width of frames of video
  double dHeight = cap.get(CV_CAP_PROP_FRAME_HEIGHT); //get height of frames of video
  Size frameSize(static_cast<int>(dWidth), static_cast<int>(dHeight));
  qDebug() << "Frame size = " << dWidth << "x" << dHeight << endl;
  VideoWriter oVideoWriter("video.avi", CV_FOURCC('M','P','E','G'), 20, frameSize);
  if(!oVideoWriter.isOpened())
  {
    qDebug() << "ERROR: Failed to write the video" << endl;
    return -1;
  }
  while(1)
  {
    Mat frame;
    bool bSuccess = cap.read(frame); //read a new frame from video
    if(!bSuccess) //if unsuccessful, break loop
    {
        qDebug() << "Cannot read frame from video file" << endl;
        break;
    }
    oVideoWriter.write(frame); //write the frame into the file
    imshow("Camera feed", frame); //show the frame in "Live Feed" window
    qDebug() << "Recording" << endl;
    if (waitKey(30) == 27)
    {
      qDebug() << "Esc key is pressed by user" << endl;
      break;
    }
  }
  return 0;
}