How can I use OpenCV (Python) to read a video file WITHOUT looping (Mac OS)?

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00:00 Question
02:29 Accepted answer (Score 2)
03:20 Thank you

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Full question
https://stackoverflow.com/questions/1670...

Question links:
[OpenCV capture loops video/Does not detect last frame]: https://stackoverflow.com/questions/1379...

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https://meta.stackexchange.com/help/lice...

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Tags
#python #opencv

#avk47

ACCEPTED ANSWER

Score 2

Don't forget to add a check if the video file has been successfully opened.

if( !cam.isOpened() )
  throw "Error when reading image file";

Grab frames by piping them into a cv::Mat in your loop

Mat frame;

for( ; ; )
{
    cam >> frame;
    if(!frame)
        break;
    imshow("w", frame);
    waitKey(20);
}

The loop should terminate correctly after frame is false.

In order to also terminate the loop exactly you could do

cam.get(CV_CAP_PROP_FRAME_COUNT)

to get the exact number of frames. Getting the video without loop is not possible as its read in increments. You could wrap this into a separate function though.