Save video using OpenCV

opencv_save_video.py

import cv2

# do something with the frame
def process_frame(frame):
  return frame

if __name__ == '__main__':
  # input and output file name
  INPUT_FILE = 'input_video.mp4'
  OUTPUT_FILE = 'output_video.mp4'
  
  # output video configuration
  FPS = 30
  WIDTH = 1280
  HEIGHT = 720
  
  # define video reader
  reader = cv2.VideoCapture(INPUT_FILE)
  
  # define video writer
  fourcc = cv2.VideoWriter_fourcc(*'MP4V')
  writer = cv2.VideoWriter(OUTPUT_FILE, fourcc, FPS, (WIDTH, HEIGHT))
  
  # read video
  while reader.isOpened():
    res, frame = reader.read()
    
    # do something with the frame
    processed_frame = process_frame(frame)
    
    # write the frame
    writer.write(processed_frame)
    
reader.release()
writer.release()