Video Capture - ( Videos in OpenCV )

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Syntax

cv2.VideoCapture(filename=None)

Example

import cv2

cap = cv2.VideoCapture('video.mp4')

while True:
    ret, frame = cap.read()
    if not ret:  # if video is completed break the loop
        break

    cv2.imshow('frame', frame)

    if cv2.waitKey(1) == ord('q'):  # press 'q' to quit
        break

cap.release()
cv2.destroyAllWindows()

Output

The output of the above code will be a window showing the frames from the video file until the user presses the 'q' key or the end of video is reached.

Explanation

OpenCV provides the cv2.VideoCapture() function for capturing video streams from various sources such as files, cameras, IP cameras, etc. This function takes in the filename or index of the video source as an argument and returns a VideoCapture object. This object can be used to read frames from the video stream.

In the above example, we capture a video from the file 'video.mp4' using the cv2.VideoCapture() function. We then read frames from this video stream using the cap.read() method in a while loop until the end of the video is reached or user presses 'q' key. Finally, we release the video capture object and destroy all windows using the cap.release(), cv2.destroyAllWindows() functions respectively.

Use

Video processing is an important aspect of computer vision. OpenCV's video capture functions allow us to read, process, and analyze videos from various sources. Video capture can be used in various applications such as surveillance, video analysis, object detection, tracking, etc.

Important Points

• OpenCV provides the cv2.VideoCapture() function for capturing video streams
• This function takes in the filename or index of the video source as an argument and returns a VideoCapture object
• The cap.read() method can be used to read frames from the video stream
• Video processing and analysis is an important aspect of computer vision

Summary

In conclusion, OpenCV's video capture functions provide a powerful and flexible way to process, analyze and manipulate video streams. The cv2.VideoCapture() function can be used to capture video from various sources and cap.read() can be used to read frames from the video stream. Video processing is an important aspect of computer vision and can be used in various applications.