OpenCV IP Camera connection

[Vijaykarthikeyan]

I'm trying to connect IP camera in Qt. For which I'm using OpenCV library. My Qt version in 5.15.2 and the OpenCV library which I have downloaded is 4.7 . Upon Building the project error hits..

The errors are:

error: undefined reference to `cv::VideoCapture::VideoCapture()'

error: undefined reference to `cv::Mat::~Mat()'

error: undefined reference to `cv::waitKey(int)'

error: undefined reference to `cv::VideoCapture::read(cv::_OutputArray const&)'

[SGaist]

Hi,

Are you linking to the OpenCV libraries ?
Which of them ?
Are they for the correct architecture ?
Are they from a compatible compiler ?

[jsulm]

@Vijaykarthikeyan Please don't double post!
You asked exact same here: https://forum.qt.io/topic/145873/how-to-connect-ip-camera-using-opencv-library-for-the-qt-version-5-15-2-im-trying-to-display-the-ip-camera-output-in-qml-window
And failed to answer my questions...

[Vijaykarthikeyan]

@SGaist Yes,sir.

I'm using OpenCV 4.7 version.

My compiler version is MINGW 8.1.0 32 bit compiler

My Qt version is 5.15.2

I actually dont know whether they are compatible..

Upon linking, I get the error like undefined reference..

This is the library which I have linked with Qt

[Vijaykarthikeyan]

@jsulm Sorry Sir..I really dont know what exactly you asked there.

[jsulm]

@Vijaykarthikeyan I asked:

• what compiler was used to build OpenCV?
• And I'm not sure whether the OpenCV library you're linking is the only one you need. Check what other libraries are there and which you need.

I will not ask again...

[Vijaykarthikeyan]

@jsulm The compiler is MINGW 8.1.0 32 bit compiler

I have gone through some pages and conluded that OpenCv 4.7 is compataible with Qt version 5.15.2

[JonB]

@Vijaykarthikeyan
Do you mean MinGW itself is 32-bit but you are building for 64-bit, or do you mean you are building for 32-bit? Because your OpenCV path contains x64...?

[Vijaykarthikeyan]

@JonB Thank you, Sir.. You are correct. There's a mismatch between the versions. Now, I have sort out the error.