convert script in SMI to SRT format

smi2srt.py

#!/usr/bin/env python
# -*- coding: UTF-8 -*-
'''
@package smi2srt
@brief this module is for convert .smi subtitle file into .srt subtitle 
	(Request by Alfred Chae)

Started : 2011/08/08
license: GPL

@version: 1.0.0
@author: Moonchang Chae <mcchae@gmail.com>


SMI have this format!
===================================================================================================

SRT have this format!
===================================================================================================
1
00:00:12,000 --> 00:00:15,123
This is the first subtitle

2
00:00:16,000 --> 00:00:18,000
Another subtitle demonstrating tags:
<b>bold</b>, <i>italic</i>, <u>underlined</u>
<font color="#ff0000">red text</font>

3
00:00:20,000 --> 00:00:22,000  X1:40 X2:600 Y1:20 Y2:50
Another subtitle demonstrating position.
'''
__author__ = "MoonChang Chae <mcchae@gmail.com>"
__date__ = "2011/08/08"
__version__ = "1.0.0"
__version_info__ = (1, 0, 0)
__license__ = "GCQVista's NDA"

###################################################################################################
import os
import sys
import re
import chardet #@UnresolvedImport

###################################################################################################
def usage(msg=None, exit_code=1):
	print_msg = """
usage %s smifile.smi [...]
	convert smi into srt subtitle file with same filename.
	By MoonChang Chae <mcchae@gmail.com>
""" % os.path.basename(sys.argv[0])
	if msg:
		print_msg += '%s\n' % msg
	print print_msg
	sys.exit(exit_code)

###################################################################################################
class smiItem(object):
	def __init__(self):
		self.start_ms = 0L
		self.start_ts = '00:00:00,000'
		self.end_ms = 0L
		self.end_ts = '00:00:00,000'
		self.contents = None
		self.linecount = 0
	@staticmethod
	def ms2ts(ms):
		hours = ms / 3600000L
		ms -= hours * 3600000L
		minutes = ms / 60000L
		ms -= minutes * 60000L
		seconds = ms / 1000L
		ms -= seconds * 1000L
		s = '%02d:%02d:%02d,%03d' % (hours, minutes, seconds, ms)
		return s
	def convertSrt(self):
		if self.linecount == 4:
			i=1 #@UnusedVariable
		# 1) convert timestamp
		self.start_ts = smiItem.ms2ts(self.start_ms)
		self.end_ts = smiItem.ms2ts(self.end_ms-10)
		# 2) remove new-line
		self.contents = re.sub(r'\s+', ' ', self.contents)
		# 3) remove web string like "&nbsp";
		self.contents = re.sub(r'&[a-z]{2,5};', '', self.contents)
		# 4) replace "<br>" with '\n';
		# self.contents = re.sub(r'(<br>)+', '\n', self.contents, flags=re.IGNORECASE)
		self.contents = re.sub(r'(<br>)+', '\n', self.contents)
		# 5) find all tags
		fndx = self.contents.find('<')
		if fndx >= 0:
			contents = self.contents
			sb = self.contents[0:fndx]
			contents = contents[fndx:]
			while True:
				m = re.match(r'</?([a-z]+)[^>]*>([^<>]*)', contents, flags=re.IGNORECASE)
				if m == None: break
				contents = contents[m.end(2):]
				#if m.group(1).lower() in ['font', 'b', 'i', 'u']:
				if m.group(1).lower() in ['b', 'i', 'u']:
					sb += m.string[0:m.start(2)]
				sb += m.group(2)
			self.contents = sb
		self.contents = self.contents.strip()
		self.contents = self.contents.strip('\n')
	def __repr__(self):
		s = '%d:%d:<%s>:%d' % (self.start_ms, self.end_ms, self.contents, self.linecount)
		return s

###################################################################################################
def convertSMI(smi_file):
	if not os.path.exists(smi_file):
		sys.stderr.write('Cannot find smi file <%s>\n' % smi_file)
		return False
	rndx = smi_file.rfind('.')
	srt_file = '%s.srt' % smi_file[0:rndx]

	ifp = open(smi_file)
	smi_sgml = ifp.read()#.upper()
	ifp.close()
	chdt = chardet.detect(smi_sgml)
	if chdt['encoding'] != 'UTF-8':
		smi_sgml = unicode(smi_sgml, chdt['encoding'].lower()).encode('utf-8')

	# skip to first starting tag (skip first 0xff 0xfe ...)
	try:
		fndx = smi_sgml.find('<SYNC')
	except Exception, e:
		print chdt
		raise e
	if fndx < 0:
		return False
	smi_sgml = smi_sgml[fndx:]
	lines = smi_sgml.split('\n')
	
	srt_list = []
	sync_cont = ''
	si = None
	last_si = None
	linecnt = 0
	for line in lines:
		linecnt += 1
		sndx = line.upper().find('<SYNC')
		if sndx >= 0:
			m = re.search(r'<sync\s+start\s*=\s*(\d+)>(.*)$', line, flags=re.IGNORECASE)
			if not m:
				raise Exception('Invalid format tag of <Sync start=nnnn> with "%s"' % line)
			sync_cont += line[0:sndx]
			last_si = si
			if last_si != None:
				last_si.end_ms = long(m.group(1))
				last_si.contents = sync_cont
				srt_list.append(last_si)
				last_si.linecount = linecnt
				#print '[%06d] %s' % (linecnt, last_si)
			sync_cont = m.group(2)
			si = smiItem()
			si.start_ms = long(m.group(1))
		else:
			sync_cont += line
			
	ofp = open(srt_file, 'w')
	ndx = 1
	for si in srt_list:
		si.convertSrt()
		if si.contents == None or len(si.contents) <= 0:
			continue
		#print si
		sistr = '%d\n%s --> %s\n%s\n\n' % (ndx, si.start_ts, si.end_ts, si.contents)
		#sistr = unicode(sistr, 'utf-8').encode('euc-kr')
		ofp.write(sistr)
		ndx += 1
	ofp.close()
	return True

###################################################################################################
def doConvert():
	if len(sys.argv) <= 1:
		usage()
	for smi_file in sys.argv[1:]:
		if convertSMI(smi_file):
			print "Converting <%s> OK!" % smi_file
		else:
			print "Converting <%s> Failture!" % smi_file
			
	
###################################################################################################
if __name__ == '__main__':
	doConvert()