display a video code error

edit

#include <iostream> // for standard I/O
#include <string>   // for strings

#include <opencv2/core.hpp>        // Basic OpenCV structures (cv::Mat)
#include <opencv2/highgui.hpp>  // Video write

using namespace std;
using namespace cv;

int main(int argc, char *argv[])
{
    const string source = argv[1];           // the source file name

    VideoCapture inputVideo(source);              // Open input
    if (!inputVideo.isOpened())
    {
        cout  << "Could not open the input video: " << source << endl;
        return -1;
    }

    Mat src;

    for(;;) //Show the image in the window and repeat
    {

        inputVideo >> src;              // read

        if (src.empty()) break;         // check if at end
        imshow( source,src );
        if( (waitKey(29) & 255) == 27 ) break; // stop by pressing ESC
    }

    return 0;
}