VideoCapture 初始化视频对象,参数为0默认调用摄像头设备,当为字符串时默认为读取字符串中的视频文件如VideoCapture cap("1.avi");
Mat frame;
VideoCapture cap(0);
if (!cap.isOpened())
{
cout << "error" << endl;
waitKey(0);
return;
}
cap >> frame;
namedWindow("show");
imshow("show", frame);
while (true)
{
// Capture the current frame
cap >> frame;
imshow("show", frame);
//waitKey(30);
if (waitKey(30) >= 0)break;
}
cap.release();
VideoCapture::isOpened¶
Returns true if video capturing has been initialized already.
- C++: bool VideoCapture:: isOpened ( )
- Python: cv2.VideoCapture. isOpened ( ) → retval
If the previous call to VideoCapture constructor or VideoCapture::open succeeded, the method returns true.
使用完摄像头设备后调用release()方法释放掉内存
参考自:
https://docs.opencv.org/3.0-beta/modules/videoio/doc/reading_and_writing_video.html