Simplifies using avconv to slice out part of a video

vslice.py

#!/usr/bin/env python

import sys
from operator import sub
from subprocess import call

def parseTime(s):
	parts = s.split(':')
	if len(parts) == 2:
		parts.insert(0, 0)
	if len(parts) != 3:
		raise Exception("Bad format")
	return list(map(int, parts))

def expressTime(t):
	return "%02d:%02d:%02d" % tuple(t)

def duration(t0, t1):
	d = map(sub, t0, t1)
	if d[2] < 0:
		d[2] += 60
		d[1] -= 1
	if d[1] < 0:
		d[1] -= 60
		d[0] -= 1
	return d

def sliceVideo(ifile, ofile, starttime, endtime):
	ss = expressTime(starttime)
	t = expressTime(duration(endtime, starttime))
	args = ["avconv", "-i", ifile, "-ss", ss, "-t", t, "-c", "copy", ofile]
	print args
	call(args)

def main(argv):
	print "Slice out a section of video using avconv"
	print "(Convert avi to mp4 to avoid choppy audio)"

	ifile = ""
	ofile = ""

	if len(argv) > 0:
		ifile = argv[0]
		print "Input file  : ", ifile
	else:
		ifile = raw_input("Input file  : ")

	if len(argv) > 1:
		ofile = argv[1]
		print "Output file : ", ofile
	else:
		ofile = raw_input("Output file : ")

	print "Enter start time and end time in HH:MM:SS format"
	stime = parseTime(raw_input("Start time  : "))
	etime = parseTime(raw_input("End time    : "))
	sliceVideo(ifile, ofile, stime, etime)

if __name__ == "__main__":
	main(sys.argv[1:])