From 7b9d037d2f45bf70182e680e6461cd40d36dc65b Mon Sep 17 00:00:00 2001
From: Jorge Gorbe <slack@codemaniacs.com>
Date: Thu, 15 Mar 2012 01:25:28 +0100
Subject: [PATCH] initial commit

---
 srtshift.py | 101 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 101 insertions(+)
 create mode 100644 srtshift.py

diff --git a/srtshift.py b/srtshift.py
new file mode 100644
index 0000000..8264d0f
--- /dev/null
+++ b/srtshift.py
@@ -0,0 +1,101 @@
+#!/usr/bin/python
+
+# Copyright (C) 2012 Jorge Gorbe Moya <jgorbe@slackito.com>
+#
+# This program is free software. It comes without any warranty, to
+# the extent permitted by applicable law. You can redistribute it
+# and/or modify it under the terms of the Do What The Fuck You Want
+# To Public License, Version 2, as published by Sam Hocevar. See
+# http://sam.zoy.org/wtfpl/COPYING for more details
+
+# Quick and dirty SRT subtitle timestamp shifting tool.
+#
+# usage: srtshift <infile> <outfile> <offset-in-seconds>
+
+import sys
+
+# possible exceptions
+class SubtitleFormatError:
+	pass
+
+# a SRT timestamp class, convertible to and from string, with a shifting(add) method
+class Timestamp:
+	def __init__(self, h, m, s, ms):
+		self.hours   = h
+		self.minutes = m
+		self.secs    = s
+		self.ms      = ms
+
+	def addSeconds(self, seconds):
+		offset_ms = int(seconds*1000)
+		# add offset to self.ms
+		ms = self.ms + offset_ms
+        # propagate to seconds
+		secs = self.secs + ms / 1000
+		ms = ms % 1000
+        #propagate to minutes
+		minutes = self.minutes + secs / 60
+		secs = secs % 60
+        #propagate to hours
+		hours = self.hours + minutes / 60
+		minutes = minutes % 60
+		# if result is negative, it will have been propagated to the hours component 
+		if hours < 0:
+			return Timestamp(0,0,0,0)
+		else:
+			return Timestamp(hours, minutes, secs, ms)
+
+
+	def __str__(self):
+		return "%02d:%02d:%02d,%03d"%(self.hours, self.minutes, self.secs, self.ms)
+
+	@classmethod
+	def fromString(cls, s):
+		items = s.split(":")
+		items[2:] = items[2].split(",")
+		hours   = int(items[0])
+		minutes = int(items[1])
+		secs    = int(items[2])
+		ms      = int(items[3])
+		return cls(hours, minutes, secs, ms)
+
+################
+# MAIN PROGRAM #
+################
+infile = open(sys.argv[1])
+outfile = open(sys.argv[2], "w")
+offset = float(sys.argv[3])
+
+subtitle_counter = 1
+
+try:
+	while True:
+		# copy subtitle number to output, check if they are consecutive
+		line = infile.next()
+		subtitle_number_from_file = int(line)
+		if subtitle_counter != subtitle_number_from_file: raise SubtitleFormatError
+		subtitle_counter += 1
+		outfile.write(line)
+
+		# parse start and end times, shift them, write to output
+		line = infile.next()
+		s1, arrow, s2 = line.split()
+		if arrow != "-->": raise SubtitleFormatError
+		t1 = Timestamp.fromString(s1).addSeconds(offset)
+		t2 = Timestamp.fromString(s2).addSeconds(offset)
+		outfile.write("%s --> %s\n"%(str(t1), str(t2)))
+
+		# copy lines to output until next subtitle (after blank line)
+		line = infile.next()
+		while line.strip() != "":
+			outfile.write(line)
+			line = infile.next()
+		outfile.write("\n")
+
+except StopIteration:
+	pass
+
+infile.close()
+outfile.close()
+
+
-- 
2.34.1