GoPro Hero4 Black C++ Streaming With OpenCV

gopro_streaming.cpp

#include <boost/exception/exception.hpp>
#include <boost/thread.hpp>
#include <boost/chrono.hpp>

#include "opencv2/opencv.hpp"
#include "opencv2/highgui.hpp"

using namespace cv;
using namespace std;


bool newFrame = false;
VideoCapture* cap;
Mat frame;
boost::mutex mtx;
boost::condition_variable cond;

void captureFunc()
{
    cap = new VideoCapture("udp://@10.5.5.9:8554");
    while (cap->isOpened())
    {
        boost::this_thread::sleep_for(boost::chrono::milliseconds(20));
        {
            boost::lock_guard<boost::mutex> lock(mtx);
            *cap >> frame;
            newFrame = true;
        }
        cond.notify_one();
    }
    return;
}

void sendToCB(const boost::system::error_code& ec)
{
    cerr << "Error " << ec.value() << endl;
}

void keepAlive()
{
    try
    {
        boost::asio::io_service ioService;
        boost::asio::ip::udp::resolver resolver(ioService);
        boost::asio::ip::udp::endpoint dest(boost::asio::ip::address::from_string("10.5.5.9"), 8554);
        boost::asio::ip::udp::socket sock(ioService, boost::asio::ip::udp::v4());

        for (;;)
        {
            boost::this_thread::sleep_for(boost::chrono::milliseconds(2000));
            sock.async_send_to(boost::asio::buffer("_GPHD_:0:0:2:0.000000\n", 22), dest,
                               boost::bind(&sendToCB, boost::asio::placeholders::error));
            cout << "Sent stay alive\n";
        }
    }
    catch (boost::exception& e)
    {
        cerr << "socket errored\n";
    }
}

int main(int argc, char** argv)
{
    namedWindow("frame");
    boost::thread capThread {captureFunc};
    boost::thread keepAliveThread {keepAlive};
    for (;;)
    {
        boost::unique_lock<boost::mutex> lock(mtx);
        while (!newFrame)
        {
            cond.wait(lock);
        }
        imshow("frame", frame);
        newFrame = false;
        if (27 == waitKey(10)) break; // the thread sleeps for longer
    }

    keepAliveThread.interrupt();
    cap->release();
    capThread.join();
    return 0;
}

This is an ancient gist, compared to the speed of GoPro releases. I believe I wrote this code for either the Hero 3 or 4. If the code does not work for you, it most likely means that they've changed their interface.