black-frame-demo-1.py

## install required packages
# $ pip install numpy opencv-python

# import required packages
import numpy as np
import cv2
from tqdm.notebook import tqdm

# specify the input video file name
fileName = './2.mkv'

# open video file
cap = cv2.VideoCapture(fileName)

# count black frame
count = 0
## use tqdm to show a progress bar
bar = tqdm(total=int(cap.get(cv2.CAP_PROP_FRAME_COUNT)), unit='f')
## for each frame in the video
while True:
  # read a frame
  valid, frame = cap.read()
  if not valid: break
  # each `frame` has shape (H, W, C)
  H, W, C = frame.shape
  ## check the center (1/2)*(1/2) only
  ## since there may be some noise at the edges
  ## count += 1 if all pixels in the center are black (0,0,0)
  h, w = H>>2, W>>2
  count += frame[h:-h, w:-w].max() == 0
  ## update the progress bar
  bar.update()
## mark progress bar as done
bar.disp(bar_style='success', check_delay=False)
  
# close
cap.release()

# print the result
print('Black frame count:', count)