Why cv::VideoCapture.open(filename) always failed

I am using unreal 4 and opencv to read web video.it works fine in editor mode,but it open video failed after packaging.

we cannot help with that

if this is running on windows, all work (on video files or urls) is done from opencv_videoio_ffmpeg455_64.dll , which has to be accessible (e.g. on the PATH)

you need to clarify that.

you know how this works. answer all the questions you can think of, before anyone has to ask them. just follow the guidelines from Stack Overflow.