https://stackoverflow.com/questions/76999557/opencv-format-equivalent-to-gstreamer-gray16-be?noredir

#include <opencv2/opencv.hpp>

int main(int argc, char* argv[])
{
    uint32_t input[8] = {
        0x01020304, 0x05060708
        , 0x11121314, 0x15161718
        , 0x21222324, 0x25262728
        , 0x31323334, 0x35363738
    };

    { // 16-bit byteswap
        // View the input array as pairs of bytes...
        cv::Mat byte_view(4, 4, CV_8UC2, input);
        std::cout << byte_view << "\n";

        // Destination array
        cv::Mat result = cv::Mat::zeros(4, 4, CV_16UC1);
        // Temporary view of the data owned by result compatible with byte_view
        cv::Mat out_view(4, 4, CV_8UC2, result.data);
        int ch[] = { 1, 0, 0, 1 };
        cv::mixChannels(&byte_view, 1, &out_view, 1, ch, 2);

        std::cout << out_view << "\n";
        std::cout << result << "\n";
    }

    { // 32-bit byteswap
        // View the input array as 4-tuples of bytes...
        cv::Mat byte_view(4, 2, CV_8UC4, input);
        std::cout << byte_view << "\n";

        cv::Mat result = cv::Mat::zeros(4, 4, CV_16UC1);
        // Temporary view of the data owned by result compatible with byte_view
        cv::Mat out_view(4, 2, CV_8UC4, result.data);
        int ch[] = { 0, 3, 1, 2, 2, 1, 3, 0 };
        cv::mixChannels(&byte_view, 1, &out_view, 1, ch, 4);

        std::cout << out_view << "\n";
        std::cout << result << "\n";
    }

    return 0;
}