How can I extract frames from a video at a certain FPS?

Question

I am able to extract the frames of a certain test.mp4 file using the following code:

import cv2
def get_frames():
    cap = cv2.VideoCapture('test.mp4')
    i = 0
    while cap.isOpened():
        ret, frame = cap.read()
        if not ret:
            break
        cv2.imwrite('test_'+str(i)+'.jpg', frame)
        i += 1

    cap.release()
    cv2.destroyAllWindows()

A lot of the frames that are extracted are useless (they're nearly identical). I need to be able to set a certain rate at which the frame extraction can be done.

Answer 1

I think you need to just skip frames based on a fixed cycle.

import cv2

def get_frames():
    cap = cv2.VideoCapture('test.mp4')
    i = 0
    # a variable to set how many frames you want to skip
    frame_skip = 10
    # a variable to keep track of the frame to be saved
    frame_count = 0
    while cap.isOpened():
        ret, frame = cap.read()
        if not ret:
            break
        if i > frame_skip - 1:
            frame_count += 1
            cv2.imwrite('test_'+str(frame_count*frame_skip)+'.jpg', frame)
            i = 0
            continue
        i += 1

    cap.release()
    cv2.destroyAllWindows()