zed_oc_video_example.cpp

Example of how to use the VideoCapture class to get raw video frames and show the stream on screen using the OpenCV library.

 
#include "videocapture.hpp"
#include "ocv_display.hpp"
 
#include <iostream>
#include <iomanip>
 
#include <opencv2/opencv.hpp>
// <---- Includes
 
// #define TEST_FPS 1
 
// The main function
int main(int argc, char *argv[])
{
    // ----> Silence unused warning
    (void)argc;
    (void)argv;
    // <---- Silence unused warning
 
    sl_oc::video::VideoParams params;
    params.res = sl_oc::video::RESOLUTION::HD720;
    params.fps = sl_oc::video::FPS::FPS_60;
 
    // ----> Create Video Capture
    sl_oc::video::VideoCapture cap_0(params);
    if( !cap_0.initializeVideo() )
    {
        std::cerr << "Cannot open camera video capture" << std::endl;
        std::cerr << "See verbosity level for more details." << std::endl;
 
        return EXIT_FAILURE;
    }
 
    std::cout << "Connected to camera sn: " << cap_0.getSerialNumber() << "[" << cap_0.getDeviceName() << "]" << std::endl;
    // <---- Create Video Capture
 
 
 
#ifdef TEST_FPS
    // Timestamp to check FPS
    double lastTime = static_cast<double>(getSteadyTimestamp())/1e9;
    // Frame timestamp to check FPS
    uint64_t lastFrameTs = 0;
#endif
 
    // Infinite video grabbing loop
    while (1)
    {
        // Get last available frame
        const sl_oc::video::Frame frame = cap_0.getLastFrame();
 
        // ----> If the frame is valid we can display it
        if(frame.data!=nullptr)
        {
#ifdef TEST_FPS
            if(lastFrameTs!=0)
            {
                // ----> System time
                double now = static_cast<double>(getSteadyTimestamp())/1e9;
                double elapsed_sec = now - lastTime;
                lastTime = now;
                std::cout << "[System] Frame period: " << elapsed_sec << "sec - Freq: " << 1./elapsed_sec << " Hz" << std::endl;
                // <---- System time
 
                // ----> Frame time
                double frame_dT = static_cast<double>(frame.timestamp-lastFrameTs)/1e9;
                std::cout << "[Camera] Frame period: " << frame_dT << "sec - Freq: " << 1./frame_dT << " Hz" << std::endl;
                // <---- Frame time
            }
            lastFrameTs = frame.timestamp;
#endif
 
            // ----> Conversion from YUV 4:2:2 to BGR for visualization
            cv::Mat frameYUV = cv::Mat( frame.height, frame.width, CV_8UC2, frame.data );
            cv::Mat frameBGR;
            cv::cvtColor(frameYUV,frameBGR,cv::COLOR_YUV2BGR_YUYV);
            // <---- Conversion from YUV 4:2:2 to BGR for visualization
 
            // Show frame
            sl_oc::tools::showImage( "Stream RGB", frameBGR, params.res  );
        }
        // <---- If the frame is valid we can display it
 
        // ----> Keyboard handling
        int key = cv::waitKey( 5 );
        if(key=='q' || key=='Q') // Quit
            break;
        // <---- Keyboard handling
    }
 
    return EXIT_SUCCESS;
}