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#!/usr/bin/env python
# -*- encoding=utf8 -*-
#
# stl2srt A program to convert EBU STL subtitle files in the more common SRT format
#
# Copyright 2014 Yann Coupin
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import struct
import codecs
import logging
import unicodedata
from xml.etree import ElementTree
import re
class SRT:
'''A class that behaves like a file object and writes an SRT file'''
def __init__(self, pathOrFile):
if isinstance(pathOrFile, file):
self.file = pathOrFile
else:
self.file = open(pathOrFile, 'wb')
self.counter = 1
self.file.write(codecs.BOM_UTF8)
def _formatTime(self, timestamp):
return "%02u:%02u:%02u,%03u" % (
timestamp / 3600,
(timestamp / 60) % 60,
timestamp % 60,
(timestamp * 1000) % 1000
)
def write(self, start, end, text):
text = "\n".join(filter(lambda (x): bool(x), text.split("\n")))
self.file.write("%0u\n%s --> %s\n%s\n\n" % (self.counter, self._formatTime(start), self._formatTime(end), text.encode('utf8')))
self.counter += 1
class iso6937(codecs.Codec):
'''A class to implement the somewhat exotic iso-6937 encoding which STL files often use'''
identical = set(range(0x20, 0x7f))
identical |= set((0xa, 0xa0, 0xa1, 0xa2, 0xa3, 0xa5, 0xa7, 0xab, 0xb0, 0xb1, 0xb2, 0xb3, 0xb5, 0xb6, 0xb7, 0xbb, 0xbc, 0xbd, 0xbe, 0xbf))
direct_mapping = {
0x8a: 0x000a, # line break
0xa8: 0x00a4, # ¤
0xa9: 0x2018, #
0xaa: 0x201C, #
0xab: 0x00AB, # «
0xac: 0x2190, #
0xad: 0x2191, #
0xae: 0x2192, #
0xaf: 0x2193, #
0xb4: 0x00D7, # ×
0xb8: 0x00F7, # ÷
0xb9: 0x2019, #
0xba: 0x201D, #
0xbc: 0x00BC, # ¼
0xbd: 0x00BD, # ½
0xbe: 0x00BE, # ¾
0xbf: 0x00BF, # ¿
0xd0: 0x2015, #
0xd1: 0x00B9, # ¹
0xd2: 0x00AE, # ®
0xd3: 0x00A9, # ©
0xd4: 0x2122, #
0xd5: 0x266A, #
0xd6: 0x00AC, # ¬
0xd7: 0x00A6, # ¦
0xdc: 0x215B, #
0xdd: 0x215C, #
0xde: 0x215D, #
0xdf: 0x215E, #
0xe0: 0x2126, # Ohm Ω
0xe0: 0x00C6, # Æ
0xe0: 0x0110, # Đ
0xe0: 0x00AA, # ª
0xe0: 0x0126, # Ħ
0xe0: 0x0132, # IJ
0xe0: 0x013F, # Ŀ
0xe0: 0x0141, # Ł
0xe0: 0x00D8, # Ø
0xe0: 0x0152, # Œ
0xe0: 0x00BA, # º
0xe0: 0x00DE, # Þ
0xe0: 0x0166, # Ŧ
0xe0: 0x014A, # Ŋ
0xe0: 0x0149, # ʼn
0xf0: 0x0138, # ĸ
0xf0: 0x00E6, # æ
0xf0: 0x0111, # đ
0xf0: 0x00F0, # ð
0xf0: 0x0127, # ħ
0xf0: 0x0131, # ı
0xf0: 0x0133, # ij
0xf0: 0x0140, # ŀ
0xf0: 0x0142, # ł
0xf0: 0x00F8, # ø
0xf0: 0x0153, # œ
0xf0: 0x00DF, # ß
0xf0: 0x00FE, # þ
0xf0: 0x0167, # ŧ
0xf0: 0x014B, # ŋ
0xf0: 0x00AD, # Soft hyphen
}
diacritic = {
0xc1: 0x0300, # grave accent
0xc2: 0x0301, # acute accent
0xc3: 0x0302, # circumflex
0xc4: 0x0303, # tilde
0xc5: 0x0304, # macron
0xc6: 0x0306, # breve
0xc7: 0x0307, # dot
0xc8: 0x0308, # umlaut
0xca: 0x030A, # ring
0xcb: 0x0327, # cedilla
0xcd: 0x030B, # double acute accent
0xce: 0x0328, # ogonek
0xcf: 0x030C, # caron
}
def decode(self, input):
output = []
state = None
count = 0
for char in input:
char = ord(char)
# End of a subtitle text
count += 1
if not state and char in self.identical:
output.append(char)
elif not state and char in self.direct_mapping:
output.append(self.direct_mapping[char])
elif not state and char in self.diacritic:
state = self.diacritic[char]
elif state:
combined = unicodedata.normalize('NFC', unichr(char) + unichr(state))
if combined and len(combined) == 1:
output.append(ord(combined))
state = None
return (''.join(map(unichr, output)), len(input))
def search(self, name):
if name in ('iso6937', 'iso_6937-2'):
return codecs.CodecInfo(self.encode, self.decode, name='iso_6937-2')
def encode(self, input):
pass
codecs.register(iso6937().search)
class RichText:
def __init__(self, use_html_tags):
self.tag_stack = []
self.opened_tags = set()
self.output = []
self.add_html_tags = use_html_tags
def write(self, string):
self.output.append(string)
def openTag(self, tag_name, tag_html=None):
if not tag_html:
tag_html = '<%s>' % tag_name
if tag_name not in self.opened_tags:
self.tag_stack.append((tag_name, tag_html))
self.opened_tags.add(tag_name)
if not self.add_html_tags:
self.output.append(' ')
else:
self.output.append(tag_html)
def closeTag(self, tag):
if not self.add_html_tags:
return
tag_html = '</%s>' % tag
if tag in self.opened_tags:
reopen_stack = []
while self.tag_stack:
tag_to_close = self.tag_stack.pop()
if tag_to_close[0] == tag:
self.output.append(tag_html)
self.opened_tags.remove(tag)
break
else:
reopen_stack += tag_to_close
for tag_to_reopen in reopen_stack:
self.output.append(tag_to_reopen[1])
self.tag_stack.append(tag_to_reopen)
def __str__(self):
if not self.add_html_tags:
return ''.join(self.output)
closing_tags = []
# Close all the tags still open
for tag in self.tag_stack[::-1]:
closing_tags.append('</%s>' % tag[0])
return ''.join(self.output + closing_tags)
class STL:
'''A class that behaves like a file object and reads an STL file'''
GSIfields = 'CPN DFC DSC CCT LC OPT OET TPT TET TN TCD SLR CD RD RN TNB TNS TNG MNC MNR TCS TCP TCF TND DSN CO PUB EN ECD UDA'.split(' ')
TTIfields = 'SGN SN EBN CS TCIh TCIm TCIs TCIf TCOh TCOm TCOs TCOf VP JC CF TF'.split(' ')
def __init__(self, pathOrFile, richFormatting=False):
if isinstance(pathOrFile, file):
self.file = pathOrFile
else:
self.file = open(pathOrFile, 'rb')
self.richFormatting = richFormatting
self._readGSI()
def __bcdTimestampDecode(self, timestamp):
# Special case for people that can't bother to read a spec
if timestamp == '________':
return 0.0
# BCD coded time with limited significant bits as per EBU Tech. 3097-E
safe_bytes = map(lambda x: x[0]&x[1], zip((0x2, 0xf, 0x7, 0xf, 0x7, 0xf, 0x3, 0xf), struct.unpack('8B', timestamp)))
return sum(map(lambda x: x[0]*x[1], zip((36000, 3600, 600, 60, 10, 1, 10.0 / self.fps, 1.0 / self.fps), safe_bytes)))
def _readGSI(self):
self.GSI = dict(zip(
self.GSIfields,
struct.unpack('3s8sc2s2s32s32s32s32s32s32s16s6s6s2s5s5s3s2s2s1s8s8s1s1s3s32s32s32s75x576s', self.file.read(1024))
))
GSI = self.GSI
logging.debug(GSI)
#self.gsiCodePage = 'cp%s' % GSI['CPN']
if GSI['DFC'] == 'STL24.01':
self.fps = 24
elif GSI['DFC'] == 'STL25.01':
self.fps = 25
elif GSI['DFC'] == 'STL30.01':
self.fps = 30
else:
raise Exception('Invalid DFC')
self.codePage = {
'00': 'iso_6937-2',
'01': 'iso-8859-5',
'02': 'iso-8859-6',
'03': 'iso-8859-7',
'04': 'iso-8859-8',
}[GSI['CCT']]
self.numberOfTTI = int(GSI['TNB'])
if GSI['TCS'] == '1':
# BCD coded time with limited significant bits
self.startTime = self.__bcdTimestampDecode(GSI['TCP'])
else:
self.startTime = 0.0
logging.debug(self.__dict__)
def __timecodeDecode(self, h, m, s, f):
return 3600 * h + 60 * m + s + float(f) / self.fps
def __parseFormatting(self, text, addHtmlTags):
colorCodes = [
'#000000', # black
'#ff0000', # red
'#00ff00', # green
'#ffff00', # yellow
'#0000ff', # blue
'#ff00ff', # magenta
'#00ffff', # cyan
'#ffffff', # white
]
currentColor = 7 # White is the default color
output = RichText(addHtmlTags)
first_line = True
for char in text:
ochar = ord(char)
if ochar == 0x80:
output.openTag('i')
elif ochar == 0x81:
output.closeTag('i')
elif ochar == 0x82:
output.openTag('u')
elif ochar == 0x83:
output.closeTag('u')
elif ochar == 0xe:
output.openTag('b')
elif ochar == 0xc:
output.closeTag('b')
elif ochar in (0,1,2,3,4,5,6,7,0x10,0x11,0x12,0x13,0x14,0x15,0x16,0x17):
color = ochar % 0x10
if color != currentColor:
currentColor = color
output.closeTag('font')
output.openTag('font', '<font color="%s">' % colorCodes[color])
elif ochar == 0x8a and first_line:
output.write("\n")
first_line = False
elif ochar == 0x8f:
break
elif (ochar & 0x7F) >= 0x20:
output.write(char)
return str(output)
def _readTTI(self):
while (True):
tci = None
tco = None
txt = []
while (True):
data = self.file.read(128)
if not data:
raise StopIteration()
TTI = dict(zip(
self.TTIfields,
struct.unpack('<BHBBBBBBBBBBBBB112s', data)
))
logging.debug(TTI)
# if comment skip
if TTI['CF']:
continue
if not tci:
tci = self.__timecodeDecode(TTI['TCIh'], TTI['TCIm'], TTI['TCIs'], TTI['TCIf']) - self.startTime
tco = self.__timecodeDecode(TTI['TCOh'], TTI['TCOm'], TTI['TCOs'], TTI['TCOf']) - self.startTime
text = TTI['TF']
text = self.__parseFormatting(text, self.richFormatting)
text = text.decode(self.codePage).strip()
txt += text
if TTI['EBN'] == 255:
# skip empty subtitles and those before the start of the show
if txt and tci >= 0:
return (tci, tco, ''.join(txt))
break
def __iter__(self):
return self
def next(self):
return self._readTTI()
class TT:
'''A class that behaves like a file object and reads a TT subtitle file'''
__named_colors = {
'black': '#000000',
'silver': '#c0c0c0',
'gray': '#808080',
'white': '#ffffff',
'maroon': '#800000',
'red': '#ff0000',
'purple': '#800080',
'fuchsia': '#ff00ff',
'magenta': '#ff00ff',
'green': '#008000',
'lime': '#00ff00',
'olive': '#808000',
'yellow': '#ffff00',
'navy': '#000080',
'blue': '#0000ff',
'teal': '#008080',
'aqua': '#00ffff',
'cyan': '#00ffff',
}
def __init__(self, source, richFormatting):
self.source = source
self.richFormatting = richFormatting
self.frameRate = 30.0
self.frameRateMultiplier = 1.0
self.subFrameRate = 1.0
self.tickRate = None
self._parseXML()
def __parse_style(self, element):
style = {}
for k, v in element.items():
if k == '{tts}color':
if re.match(r'#\d{6}\d{2}?', v):
style['color'] = v[0:7]
else:
rgb_color = re.match(r'rgb\(\s*(\d+)\s*,\s*(\d+)\s*,\s*(\d+)\s*\)', v.strip())
if rgb_color:
style['color'] = '#%02x%02x%02x' % (int(rgb_color.group(1)), int(rgb_color.group(2)), int(rgb_color.group(3)))
else:
c = self.__named_colors.get(v)
if c:
style['color'] = c
elif k == '{tts}fontStyle':
style['italic'] = v == 'italic'
elif k == '{tts}fontWeight':
style['bold'] = v == 'bold'
elif k == '{tts}textDecoration':
style['underline'] = v == 'underline'
return style
def __process_time(self, text):
coefs = [3600, 60, 1]
time = 0.0
offset_match = re.match(r'(\d+)(:?\.\d+)?(h|m|s|ms|f|t)', text)
if offset_match:
return float(offset_match.group(1)) * {
'h': 3600.0,
'm': 60.0,
's': 1.0,
'ms': 0.001,
'f': 1.0/(self.frameRate * self.frameRateMultiplier),
't': 1.0/self.tickRate
}.get(offset_match.group(2), 1.0)
params = text.split(':')
if len(params) in (3, 4):
if len(params) == 4:
frames = params[3].split('.', 2)
if len(frames) == 1:
params[2] = float(params[2]) + float(params[3]) / (self.frameRate * self.frameRateMultiplier)
else:
params[2] = float(params[2]) + (
float(frames[0]) / self.frameRate +
float(frames[1]) / (self.frameRate * self.subFrameRate)
) * self.frameRateMultiplier
del params[3]
for c, v in zip(coefs, params):
time += c*float(v)
return time
return 0.0
def _parseXML(self):
# Normalize namespaces to a single alias. The draft namespace are still used in some file which makes searching for tags cumbersome
namespace_clean = {
'http://www.w3.org/2006/10/ttaf1': 'tt',
'http://www.w3.org/2006/04/ttaf1': 'tt',
'http://www.w3.org/ns/ttml': 'tt',
'http://www.w3.org/2006/10/ttaf1#styling': 'tts',
'http://www.w3.org/2006/04/ttaf1#styling': 'tts',
'http://www.w3.org/ns/ttml#styling': 'tts',
'http://www.w3.org/2006/10/ttaf1#parameter': 'ttp',
'http://www.w3.org/2006/04/ttaf1#parameter': 'ttp',
'http://www.w3.org/ns/ttml#parameter': 'ttp',
}
def normalize_qname(name):
if name[0] == '{':
(ns, name) = name[1:].split('}', 1)
ns = namespace_clean.get(ns, ns)
return '{%s}%s' % (ns, name)
return name
xml = ElementTree.parse(self.source)
for element in xml.getiterator():
element.tag = normalize_qname(element.tag)
for k, v in element.items():
new_k = normalize_qname(k)
if k != new_k:
del element.attrib[k]
element.attrib[new_k] = v
# Define style aliases
styles = {}
regions = {}
root = xml.getiterator()[0]
if int(root.get('{ttp}tickRate', 0)) > 0:
self.tickRate = int(root.get('{ttp}tickRate'))
if int(root.get('{ttp}frameRate', 0)) > 0:
self.frameRate = int(root.get('{ttp}frameRate'))
if int(root.get('{ttp}subFrameRate', 0)) > 0:
self.subFrameRate = int(root.get('{ttp}subFrameRate'))
if root.get('{ttp}frameRateMultiplier'):
num, denom = root.get('{ttp}frameRateMultiplier').split(' ')
self.frameRateMultiplier = float(num) / float(denom)
if not self.tickRate:
self.tickRate = self.frameRate * self.subFrameRate * self.frameRateMultiplier
# Build a cache for the default styles
for style_tag in xml.findall('{tt}head/{tt}styling/{tt}style'):
style = self.__parse_style(style_tag)
styles[style_tag.get('{http://www.w3.org/XML/1998/namespace}id')] = style
# Build a cache for the default style of the regions
for region_tag in xml.findall('{tt}head/{tt}layout/{tt}region'):
region = self.__parse_style(region_tag)
regions[region_tag.get('{http://www.w3.org/XML/1998/namespace}id')] = region
def compute_style_tree(element):
style_ref = element.get('style')
region_ref = element.get('region')
style = {}
if region_ref:
style.update(regions[region_ref])
if style_ref:
style.update(styles[style_ref])
style.update(self.__parse_style(element))
return style
def styleToHtml(tag, value):
return {
'bold': ('b', '<b>'),
'italic': ('i', '<i>'),
'underline': ('u', '<u>'),
'color': ('font', '<font color="%s">' % value),
}[tag]
def openTags(output, style_pairs):
(before, after) = style_pairs
for tag in sorted(after.keys()):
new_value = after[tag]
old_value = before.get(tag, None)
if old_value == None and new_value:
html = styleToHtml(tag, new_value)
output.openTag(html[0], html[1])
elif old_value != new_value:
if new_value:
html = styleToHtml(tag, new_value)
output.openTag(html[0], html[1])
else:
output.closeTag(styleToHtml(tag, new_value)[0])
def closeTags(output, style_pairs):
(before, after) = style_pairs
for tag in sorted(after.keys(), reverse=True):
new_value = after[tag]
old_value = before.get(tag, None)
if old_value == None and new_value:
output.closeTag(styleToHtml(tag, new_value)[0])
elif old_value != new_value:
if new_value:
output.closeTag(styleToHtml(tag, new_value)[0])
else:
html = styleToHtml(tag, before[tag])
output.openTag(html[0], html[1])
# Store the subs in a list
self.subs = []
prev_sub = None
content = None
sub_grouping = False
for sub in xml.findall('{tt}body/{tt}div/{tt}p'):
begin = self.__process_time(sub.get('begin'))
if not sub.get('end'):
end = begin + self.__process_time(sub.get('dur'))
else:
end = self.__process_time(sub.get('end'))
style_stack = [{'color': '#ffffff'}] # default color
if not prev_sub or begin != prev_sub[0] or end != prev_sub[1]:
content = RichText(self.richFormatting)
sub_grouping = False
else:
content.write("\n")
sub_grouping = True
def parseChildTree(element_list):
for child in element_list:
style_stack.append(compute_style_tree(child))
openTags(content, style_stack[-2:])
if child.text and child.text.strip():
content.write(child.text.strip())
if child.tag == '{tt}br':
content.write("\n")
parseChildTree(child.getchildren())
if child.tail and child.tail.strip():
content.write(child.tail.strip())
closeTags(content, style_stack[-2:])
style_stack.pop()
parseChildTree([sub])
# try to regroup subtitles if possible
if sub_grouping:
self.subs[-1][2] = unicode(content)
else:
prev_sub = [begin, end, unicode(content)]
self.subs.append(prev_sub)
def __iter__(self):
return iter(self.subs)
if __name__ == '__main__':
from optparse import OptionParser
import sys
parser = OptionParser(usage = 'usage: %prog [options] input output')
parser.set_defaults(reader_class=STL)
parser.add_option('-d', '--debug', dest='debug_level', action='store_const', const=logging.DEBUG, default=logging.ERROR)
parser.add_option('-r', '--rich', dest='rich_formatting', action='store_true', default=False, help='Output text with some formatting, the following HTML tags are used: b i u font(color)')
parser.add_option("-s", "--stl", dest="reader_class", action="store_const", const=STL,
help="Set input file format as STL (default)")
parser.add_option("-t", "--tt", dest="reader_class", action="store_const", const=TT,
help="Set input file format as TT, handles both the EBU and SMPTE variants")
(options, args) = parser.parse_args()
if len(args) != 2:
parser.print_help()
sys.exit(1)
logging.basicConfig(level=options.debug_level)
input = options.reader_class(args[0], options.rich_formatting)
c = SRT(args[1])
for sub in input:
(tci, tco, txt) = sub
c.write(tci, tco, txt)