从网络摄像头流式传输：是正常的框架没有refcount？ [英] Streaming from webcam: is it normal that the frame does not have refcount?

问题描述

我有以下代码：

 ＃include< opencv2 / core / core.hpp> 
＃include< opencv2 / highgui / highgui.hpp> 
 int main（）
 {
 cv :: VideoCapture capture（0）; 
 cv :: Mat frame; 
 capture>> frame; 
 cv :: Mat img = frame.clone（）; 
 cv :: Mat img2 = frame; //这里仍然引用计数在xcode中保持为null。 
 return 0; 
} 
  

然后

  frame.refcount == NULL; //可能是错误的
 img-> refcount == 1; // good 
 img2.refcount == NULL; //肯定错了，应该指向2，在与frame.refcount相同的地址。 
  

一切似乎都工作正常，但我已经查看了事情，结果是， 框架只是一个空指针（并保留在 clone（）之后），而其他mat ）的引用计数指向一个int> = 0。

这是什么原因？

方案

根据文档： p>

clone（）返回矩阵的深度复制，即复制数据。 / p>

所以有理由的是， refcount没有增加强>。有关此主题的详情，请参阅内存管理和引用计数。

I have the following code:

#include<opencv2/core/core.hpp>
#include<opencv2/highgui/highgui.hpp>
int main()
{
    cv::VideoCapture capture(0);
    cv::Mat frame;
    capture>>frame;
    cv::Mat img = frame.clone();
    cv::Mat img2 = frame; // here still the refcount stays null in xcode.
    return 0;
}

then

frame.refcount ==NULL; // could be wrong
img->refcount == 1; // good
img2.refcount ==NULL; // certainly wrong, should be pointing to 2, at the same address as frame.refcount.

Everything seems to be working fine, but I have looked into things and it turned out that the refcount of the frame is just a null pointer (and stays so after clone()), whereas other mats (say its clone) have refcount pointing to an int >= 0.

What is the reason for this?

解决方案

According to the docs:

clone() returns deep copy of the matrix, i.e. the data is copied.

So it makes sense that there's no increase in refcount. For more information on this subject, take a look at Memory management and reference counting.

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