Dereferencing " cv::Mat* " pointer to cv::Mat to Receive Gstreamer Video and Use in OpenCV

Question

I'm working on receiving video stream from source. (Gazebo Simulation) First of all, I'm succesful to receive on python side, but I want to move code C++. This is python code: Python code Also I can easily add tracker to python by using:

video = Video()
frame = video.frame()
bbox = (287, 23, 86, 320)
ok = tracker.init(frame, bbox)

But when I tried to same thing on C++ it's not possible to pass easily these steps. I used this code and this is working fine: C++ Code Gstream

But I couldn't be able to use like opencv. Key code lines are:

        // Main loop
    while(1) {
        g_main_iteration(false);

        cv::Mat* frame = atomicFrame.load();

        if(frame) {
            cv::imshow("Frame", frame[0]);
            cv::waitKey(30);
        }
    }

When I tried to add basic text like:

putText(frame[0], " Hello", Point(100,20), FONT_HERSHEY_SIMPLEX, 0.75, Scalar(50,170,50),2);

I'm getting hard "Segmentation fault".

I tried also use single line to receive video normal way:

VideoCapture video("udpsrc port=5600 ! application/x-rtp, payload=96 ! rtph264depay ! h264parse ! avdec_h264! decodebin ! videoconvert ! video/x-raw,format=(string)BGR ! videoconvert! appsink name=sink emit-signals=true sync=false max-buffers=1 drop=true",CAP_GSTREAMER);

But video couldn't be open.

Answer 1

It is not necessary anymore to convert cv::Mat* to cv::Mat. Furthermore, it's not logical.

Here is current pipeline that working without error in Gazebo Simulation:

VideoCapture video("udpsrc port=5600 ! application/x-rtp,payload=96,encoding-name=H264 ! rtpjitterbuffer mode=1 ! rtph264depay ! h264parse ! decodebin ! videoco