1#!/usr/local/bin/python3.8
2
3#usage:
4#
5# vobshift.py in.idx out.idx -8.45
6#
7# this will read in in.idx,shift it by 8.45 seconds back,
8# and save it as out.idx
9#
10# license: i don't care ;)
11#
12
13import datetime
14import sys
15
16def tripletize(line):
17	begin = line[:11]
18	middle = line[11:23]
19	end = line[23:]
20	return (begin,middle,end)
21
22def text2delta(t):
23	h = int( t[0:2] )
24	m = int( t[3:5] )
25	s = int( t[6:8] )
26	milli = int( t[9:12] )
27	return datetime.timedelta(hours=h,minutes=m,seconds=s,milliseconds=milli)
28
29def delta2text(d):
30	t = str(d)
31	milli = t[8:11]
32	if len(milli) == 0: #fix for .000 seconds
33	    milli = '000'
34	return '0'+t[:7]+':'+milli
35
36def shift(line,seconds):
37	triplet = tripletize(line)
38
39	base = text2delta(triplet[1])
40	base = base + datetime.timedelta(seconds=seconds)
41	base = delta2text(base)
42
43	return triplet[0]+base+triplet[2]
44
45INFILE  =sys.argv[1]
46OUTFILE =sys.argv[2]
47DIFF    =float(sys.argv[3])
48
49o = open(OUTFILE,'wt')
50
51
52for line in open(INFILE):
53    if line.startswith('timestamp'):
54	line = shift(line,DIFF)
55
56    o.write(line)
57
58o.close()
59