downsample.py

import cv2
import numpy as np

capture = cv2.VideoCapture('Set01_video01.mp4')
size = (
    int(capture.get(cv2.CAP_PROP_FRAME_WIDTH)),
    int(capture.get(cv2.CAP_PROP_FRAME_HEIGHT))
)
codec = cv2.VideoWriter_fourcc(*'DIVX')
output = cv2.VideoWriter('video7.avi', codec, 10.0, size)

i = 0
frame_rate_divider = 3
while(capture.isOpened()):
    ret, frame = capture.read()
    if ret:
        if i % frame_rate_divider == 0:
            # frame = cv2.resize(frame, None, fx=0.5, fy=0.5, interpolation=cv2.INTER_CUBIC)
            output.write(frame)
            cv2.imshow('frame', frame)
            i += 1
        else:
            i += 1
        if cv2.waitKey(1) & 0xFF == ord('q'):
            break
    else:
        break

capture.release()
output.release()
cv2.destroyAllWindows()