extract highlights from video using list of timestamps

extract_highlights.py

import os, subprocess, sys

# usage: extract_highlights.py <path-to-video> <path-to-timestamps>
# timestamps file format:
# hh:mm:ss bla bla bla

before_secs = 5 # secs to include before clip timestamp
after_secs = 25 # -"- after -" ... 5+25 = 30 sec clip
safe_chars = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ -0123456789."

def hhmmss_to_sec(hhmmss):
	hours = int(hhmmss.split(":")[0])
	mins = int(hhmmss.split(":")[1])
	secs = int(hhmmss.split(":")[2])
	hours_to_secs = hours*60*60
	mins_to_secs = mins*60
	total = hours_to_secs + mins_to_secs + secs
	return total

def safe_filename(text):
	string = []
	for c in text:
		if c in safe_chars:
			string.append(c)
	return "".join(string)

def extract_video(videofile, timestamp, before, after, outfile):
	timestamp = str(hhmmss_to_sec(timestamp) - before)
	duration = str(before+after)
	command = ["ffmpeg", "-loglevel", "error", "-ss", str(timestamp), "-i", videofile, "-t", duration, "-crf", "17", "-b:a", "320k", "-pix_fmt", "yuv420p", outfile]
	print("Extracting", outfile)
	subprocess.call(command)

video = sys.argv[1]
text = sys.argv[2]
folder_name = os.path.splitext(text)[0]

if not os.path.isfile(video):
	print("is not video file:", video)
if not os.path.isfile(text):
	print("is not text file:", text)
if not os.path.isdir(folder_name):
	os.makedirs(folder_name)

with open(text, encoding="utf8") as f:
	lines = f.readlines()

for line in lines:
	print()
	time = line.split(" ")[0]
	filename = folder_name + "/" + safe_filename(folder_name + "-" + line) + ".mp4"
	extract_video(video, time, before_secs, after_secs, filename)