timelapse.py

import math
import subprocess
import os
import sys
import shutil

SEC_LENGTH = 30 # section length - actual time (s)
SEC_SEP = 120 # time spetween sections - actual time (s)
SPEEDUP = 20
FPS_SOURCE = 60
FPS_FINAL = 25
TMP_DIR = "tmp"
PART_LENGTH = 59 # time - output time (s)

def ffmpeg(cmd):
    print("ffmpeg command: {}".format(cmd))
    subprocess.run("{} -nostdin -y -hide_banner".format(cmd), shell=True)


def del_temp():
	if os.path.exists(TMP_DIR) and os.path.isdir(TMP_DIR):
		shutil.rmtree(TMP_DIR)

files = [x for x in os.listdir() if os.path.splitext(x)[1] in [".mkv", ".flv"]]
if len(files) != 1:
	print('invalid number of files')
	input()
	sys.exit()
file = files[0]
	
# ffmpeg -i "2019-11-17 03-08-45.mkv" -vf fps=30/x tmp/%010d.png # x speed up amount (x times)
# ffmpeg -y -i tmp/%010d.png -c:v libx264rgb -crf 23 tmp1.mp4

# 1:16 --> 00:15
# when fps=2: 1:16 --> 00:06

del_temp()
os.makedirs(TMP_DIR)
ffmpeg('ffmpeg -i "{}" -vf fps={}/{} {}/%010d.png'.format(file, FPS_SOURCE, SPEEDUP, TMP_DIR))

images = os.listdir(TMP_DIR)
selected_images = []
discarded_images = []

t = 0
in_sec = True
for image in images:
	if not in_sec:
		discarded_images.append(image)
		if t >= SEC_SEP:
			in_sec = True
			t = 0
	else:
		selected_images.append(image)
		if t >= SEC_LENGTH:
			in_sec = False
			t = 0

	t += SPEEDUP/FPS_FINAL

for image in discarded_images:
	os.remove(os.path.join(TMP_DIR, image))

for i, image in enumerate(selected_images):
	os.rename(os.path.join(TMP_DIR, image), os.path.join(TMP_DIR, "{:010d}{}".format(i, os.path.splitext(image)[1])))

ffmpeg("ffmpeg -y -i {}/%010d.png -c:v libx264 -pix_fmt yuv420p -crf 23 out.mp4".format(TMP_DIR))

# 10,30,20 => 1:02:12 -> 00:00:57
# 30,120,20 => 2:10:51 -> 00:01:35

# split into parts for insta
images = os.listdir(TMP_DIR)
folders = []

part_no = 0
i = 0
os.mkdir(os.path.join(TMP_DIR, str(part_no)))

for image in images:
	if i >= PART_LENGTH*FPS_FINAL:
		part_no += 1
		os.mkdir(os.path.join(TMP_DIR, str(part_no)))
		i = 0
	os.rename(os.path.join(TMP_DIR, image), os.path.join(TMP_DIR, str(part_no), '{:010d}{}'.format(i, os.path.splitext(image)[1])))
	i += 1

for i in range(part_no+1):
	ffmpeg("ffmpeg -y -i {}/%010d.png -vf scale=1080:-1 -c:v libx264 -pix_fmt yuv420p -crf 23 out{}.mp4".format(os.path.join(TMP_DIR, str(i)), str(i)))

del_temp()