CODEWITHSUNDEEP
pythonopencvvideo
Frankie
Frankie

Reputation: 784

How to get the duration of video using OpenCV

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

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

How to do that?

Thank you very much.

Upvotes: 38

Views: 78146

Answers (6)

Mitiku
Mitiku

Reputation: 5412

First calculate frame per second like this

import cv2 as cv
# cap = cv.VideoCapture...
fps = cap.get(cv.CAP_PROP_FPS)

Then duration can be calculated as (number of frames) / (frames per second)

 duration = float(num_frames) / float(fps) # in seconds

Upvotes: 5

FantasyJXF
FantasyJXF

Reputation: 984

I noticed a weird phenomenon that many video DO NOT HAVE as much frames as the vid.get(cv.CAP_PROP_FRAME_COUNT) gets.

I suppose that the video duration should be the divided value of TOTAL FRAMES by FPS, but it always mismatch. The video duration would be longer than we calculated. Considering what FFMPEG does, the original video might has some empty frames.

Hope this help.

Upvotes: 1

Joseph Yosoevsky
Joseph Yosoevsky

Reputation: 41

In my personal experience I've been using the OpenCV method. Try this code:

import cv2 as cv

def get_dur(filename):
    video = cv.VideoCapture(filename)
    fps = video.get(cv.CAP_PROP_FPS)
    frame_count = video.get(cv.CAP_PROP_FRAME_COUNT)
    seconds = frame_count / fps
    minutes = int(seconds / 60)
    rem_sec = int(seconds % 60)
    return f"{minutes}:{rem_sec}"

print(get_dur("dafuck.mp4"))

Upvotes: 2

lakjeewa Wijebandara
lakjeewa Wijebandara

Reputation: 562

Capture the video and output the duration is seconds

import cv2 as cv
vidcapture = cv.VideoCapture('myvideo.mp4')
fps = vidcapture.get(cv.CAP_PROP_FPS)
totalNoFrames = vidcapture.get(cv.CAP_PROP_FRAME_COUNT)
durationInSeconds = totalNoFrames / fps

print("durationInSeconds:", durationInSeconds, "s")

Upvotes: 8

ivan_pozdeev
ivan_pozdeev

Reputation: 35986

OpenCV 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:

>>> import cv2 as cv
>>> v = cv.VideoCapture('sample.avi')
>>> v.set(cv.CAP_PROP_POS_AVI_RATIO, 1)
True
>>> v.get(cv.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(cv.CAP_PROP_POS_FRAMES)
5335.0
>>>> v.get(cv.CAP_PROP_FRAME_COUNT)
5335.0

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

Upvotes: 38

Ryan Loggerythm
Ryan Loggerythm

Reputation: 3314

In OpenCV 3, the solution is:

import cv2 as cv

cap = cv.VideoCapture("./video.mp4")
fps = cap.get(cv.CAP_PROP_FPS)      # OpenCV v2.x used "CV_CAP_PROP_FPS"
frame_count = int(cap.get(cv.CAP_PROP_FRAME_COUNT))
duration = frame_count/fps

print('fps = ' + str(fps))
print('number of frames = ' + str(frame_count))
print('duration (S) = ' + str(duration))
minutes = int(duration/60)
seconds = duration%60
print('duration (M:S) = ' + str(minutes) + ':' + str(seconds))

cap.release()

Upvotes: 64

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