How to get the duration of video using cv2

Question

I can only get the number of frames CAP_PROP_FRAME_COUNT using CV2.

However, I cannot find the parameter to get the duration of the video using cv2.

Answer 1

cv2 is not designed to explore video metadata, so VideoCapture doesn't have API to retrieve it directly.

You can instead "measure" the length of the stream: seek to the end, then get the timestamp:

>>> v=cv2.VideoCapture('sample.avi')
>>> v.set(cv2.CAP_PROP_POS_AVI_RATIO,1)
True
>>> v.get(cv2.CAP_PROP_POS_MSEC)
213400.0

Checking shows that this sets the point after the last frame (not before it), so the timestamp is indeed the exact total length of the stream:

>>> v.get(cv2.CAP_PROP_POS_FRAMES)
5335.0
>>>> v.get(cv2.CAP_PROP_FRAME_COUNT)
5335.0

>>> v.set(cv2.CAP_PROP_POS_AVI_RATIO,0)
>>> v.get(cv2.CAP_PROP_POS_FRAMES)
0.0        # the 1st frame is frame 0, not 1, so "5335" means after the last frame