Compress image sequence into MP4 video

mp4_compress.py

#!/usr/bin/python

import os
import argparse
import cv2

def is_image_file(filename):
    """ Check whether the file name sounds like an image """
    image_extensions = ['.jpg', '.jpeg', '.png', '.bmp', '.tiff', '.tif']
    _, ext = os.path.splitext(filename)
    return ext in image_extensions

def compress(input_folder, output_file, frame_rate):
    """ Compress image sequence into an video with specified frame rate """
    # Retrieve image files
    image_files = filter(is_image_file, os.listdir(input_folder))
    image_files = [os.path.join(input_folder, f) for f in image_files]
    image_files = sorted(image_files)
    num_images = len(image_files)
    print('#image: {}'.format(num_images))

    # Video format
    dummy = cv2.imread(image_files[0], cv2.IMREAD_GRAYSCALE)
    size = dummy.shape
    size = (size[1], size[0])
    fmt = cv2.VideoWriter_fourcc('m', 'p', '4', 'v')

    # Write frames to video
    writer = cv2.VideoWriter(output_file, fmt, frame_rate, size)
    for i, f in enumerate(image_files):
        print('[{0} / {1}] {2}'.format(i + 1, num_images, f))
        frame = cv2.imread(f, cv2.IMREAD_COLOR)
        writer.write(frame)
    writer.release()

if __name__ == '__main__':
    # Parse input arguments
    parser = argparse.ArgumentParser(description='Compress image sequence into MP4 video')
    parser.add_argument('-i', '--input', type=str, default='.',
                        help='Input folder which stores image sequence')
    parser.add_argument('-o', '--output', type=str, default=None,
                        help='Output file name')
    parser.add_argument('--fps', type=float, default=29.97,
                        help='Output video frame rate [default: 29.97]')
    args = parser.parse_args()

    # Setup output file name
    input_folder = os.path.abspath(args.input)
    output_file = args.output
    fps = args.fps
    if output_file is None:
        output_file = os.path.basename(input_folder) + '.mp4'

    print('Input: {}'.format(input_folder))
    print('Output: {}'.format(output_file))

    # Run
    compress(input_folder, output_file, fps)