Help with using raspberry pi camera on openCV

[lucaderaad]

I am trying to run openCV in C++ and capture the camera input.

The program looks like this:

#include <iostream>
#include <sstream>
#include <new>
#include <string>
#include <sstream>

#include <opencv2/opencv.hpp>
#include <opencv2/core.hpp>
#include <opencv2/imgcodecs.hpp>
#include <opencv2/highgui.hpp>

#define INPUT_WIDTH 3264
#define INPUT_HEIGHT 2464

#define DISPLAY_WIDTH 640
#define DISPLAY_HEIGHT 480

#define CAMERA_FRAMERATE 21/1
#define FLIP 2

void DisplayVersion()
{
    std::cout << "OpenCV version: " << cv::getVersionMajor() << "." << cv::getVersionMinor() << "." << cv::getVersionRevision() << std::endl;
}

int main(int argc, const char** argv)
{
    DisplayVersion();

    std::stringstream ss;

    ss << "nvarguscamerasrc !  video/x-raw(memory:NVMM), width=3264, height=2464, format=NV12, framerate=21/1 ! nvvidconv flip-method=2 ! video/x-raw, width=480, height=680, format=BGRx ! videoconvert ! video/x-raw, format=BGR ! appsink";

    //ss << "nvarguscamerasrc !  video/x-raw(memory:NVMM), width=" << INPUT_WIDTH <<
    //", height=" << INPUT_HEIGHT <<
    //", format=NV12, framerate=" << CAMERA_FRAMERATE <<
    //" ! nvvidconv flip-method=" << FLIP <<
    //" ! video/x-raw, width=" << DISPLAY_WIDTH <<
    //", height=" << DISPLAY_HEIGHT <<
    //", format=BGRx ! videoconvert ! video/x-raw, format=BGR ! appsink";

    cv::VideoCapture video;

    video.open(ss.str());

    if (!video.isOpened())
    {
        std::cout << "Unable to get video from the camera!" << std::endl;

        return -1;
    }

    std::cout << "Got here!" << std::endl;

    cv::Mat frame;

    while (video.read(frame))
    {
        cv::imshow("Video feed", frame);

        if (cv::waitKey(25) >= 0)
        {
            break;
        }
   }

    std::cout << "Finished!" << std::endl;

    return 0;
}

When running this code I get the following outout:
OpenCV version: 4.6.0
nvbuf_utils: Could not get EGL display connection
Error generated. /dvs/git/dirty/git-master_linux/multimedia/nvgstreamer/gst-nvarguscamera/gstnvarguscamerasrc.cpp, execute:751 Failed to create CaptureSession
[ WARN:0@0.269] global /tmp/build_opencv/opencv/modules/videoio/src/cap_gstreamer.cpp (1405) open OpenCV | GStreamer warning: Cannot query video position: status=0, value=-1, duration=-1
Got here!
Finished!

If I run the other commented command to video.open() I get this output:

OpenCV version: 4.6.0
nvbuf_utils: Could not get EGL display connection
Error generated. /dvs/git/dirty/git-master_linux/multimedia/nvgstreamer/gst-nvarguscamera/gstnvarguscamerasrc.cpp, execute:751 Failed to create CaptureSession

I’m currently running this from headless mode.

I also know that OpenCV and xlaunch works because I can use mjpeg streamer from my laptop and successfully stream my laptop camera feed to my jetson nano by using video.open(http://laptop-ip:laptop-port/); and that works correctly (OpenCV is able to display a live video feed using xlaunch just fine).

I think this command is telling me my camera is successfully installed:

$ v4l2-ctl -d /dev/video0 --list-formats-ext
ioctl: VIDIOC_ENUM_FMT
        Index       : 0
        Type        : Video Capture
        Pixel Format: 'RG10'
        Name        : 10-bit Bayer RGRG/GBGB
                Size: Discrete 3264x2464
                        Interval: Discrete 0.048s (21.000 fps)
                Size: Discrete 3264x1848
                        Interval: Discrete 0.036s (28.000 fps)
                Size: Discrete 1920x1080
                        Interval: Discrete 0.033s (30.000 fps)
                Size: Discrete 1640x1232
                        Interval: Discrete 0.033s (30.000 fps)
                Size: Discrete 1280x720
                        Interval: Discrete 0.017s (60.000 fps)

Any help would be much appreciated

[ShaneCCC]

Maybe need below command before run it.

export DISPLAY=:0

[lucaderaad]

Restarting the nano again fixed the problem. Thanks for the help anyways!