libcaffe.so: undefined reference to `cv::VideoCapture::isOpened() const' code example

Example: undefined reference to `cv::VideoCapture::VideoCapture(cv::String const&)'

prashad@ubuntu:~/test$ g++ open_videofile.cpp  `pkg-config --cflags --libs opencv` 


Explanation:
need to compile opencv programs with `pkg-config --cflags --libs opencv` . 
it solve below undefined reference errors:

undefined reference to `cv::VideoCapture::VideoCapture(cv::String const&)'