How to Open a video file on OpenCV 3.1.0

videoio.cpp

#include <opencv2/highgui/highgui.hpp>
#include <opencv2/imgproc/imgproc.hpp>
#include <iostream>

int main() {
  cv::VideoCapture cap;
  cap.open("myVideo.mp4" );
  cv::namedWindow( "myVideo", cv::WINDOW_AUTOSIZE );
  cv::Mat frame;
  while(true) {
    cap >> frame;
    if( frame.empty() ){
      std::cout << "Could not load the video frames. \n";
      break;
    }
    cv::imshow( "myVideo", frame );
    if( cv::waitKey(27) >= 0 ){
      std::cout << "Escape pressed \n";
      break;
    }
  }
  return 0; 
}