Python and OpenCV - getting the duration time of a video at certain points

Question

Let say I have made a program to detect a green ball in a video. Whenever there is a green ball detected, I want to print out the duration of video at the time the green ball is detected. Is it possible?

Answer 1

In this answer, you will find a solution to determine the frames per second.

so you'd want to use:

fps = cap.get(cv2.cv.CV_CAP_PROP_FPS)

and count the number of frames you're at. Then you can compute the video time with

videotime = current_frame_number / fps.

EDIT:

@Miki suggested to use CAP_PROP_POS_MSEC which should result in the same time (in [ms])

Corrected my typo as pointed out by @Swiper-CCCVI

Answer 2

You can simply measure a certain position in the video in milliseconds using

time_milli = cap.get(cv2.CAP_PROP_POS_MSEC)

and then divide time_milli by 1000 to get the time in seconds.