convert frames to video with OpenCV

frames_to_video.py

import cv2
import os
from os.path import isfile,join

input = '/' #folder of frames
output = 'framestovideo.mp4' #output path

fps = 25 #default 25
frame_array = []
frames = [f for f in os.listdir(input) if isfile(join(input, f))]
frames.sort(key=lambda x: x[5-4])
frames.sort()

for i in range(len(frames)):
    filename = input + frames[i]
    # reading each files
    img = cv2.imread(filename)
    height, width, layers = img.shape
    size = (width, height)
    frame_array.append(img)

out = cv2.VideoWriter(output, cv2.VideoWriter_fourcc('M','J','P','G'), fps, size)
for i in range(len(frame_array)):
    # writing to a image array
    out.write(frame_array[i])
    print("Writing frame {} to video".format(i))
out.release()