opencv processing each frame of video playback, reads the video failed

cv::VideoCapture capture(filename);
if (!capture.isOpened())
{
cout << "open video error";
}

 

Every show is always open failure

Solution:

1) filename write the wrong path 

There is no corresponding version of the dll under 2) projects, such as version 3.3.1 I will increase opencv_ffmpeg331_64.dll this dynamic library