Video capturing with OpenCV errors

Question

How do I read a video using OpenCV? I read like this:

video = cv2.VideoCapture("videos/chaplin.avi")

And I get this error:

[ERROR:0] global C:\projects\opencv-python\opencv\modules\videoio\src\cap.cpp (142) cv::VideoCapture::open VIDEOIO(CV_IMAGES): raised OpenCV exception:
OpenCV(4.3.0) C:\projects\opencv-python\opencv\modules\videoio\src\cap_images.cpp:253: error: (-5:Bad argument) CAP_IMAGES: can't find starting number (in the name of file): videos/chaplin.avi in function 'cv::icvExtractPattern'

Could not open video

Answer 1

I had the same problem, compilation and linking ok, but the same cryptic error occurs at running.

It happened (with Windows) when opencv_videoio_ffmpeg430_64.dll was not accessible (it seems to be silently called by another opencv lib). Either you did not build opencv with the -DWITH_FFMPEG=ON, or alternatively your dll is not in the path.