How to find out the frame rate of a video?

Question

How to find out the frame rate of a video ?How to do in C++ OpenCV?

I want to read the different number of video with respective of frames per second.

It has to work on all Video formats? .Avi, .MP4, .Flv

Answer 1

easy (just take with a grain of salt, see remarks below):

VideoCapture cap("ma.avi");
double fps = cap.get(CV_CAP_PROP_FPS);