[refactor] Single quotes consistency
[youtube-dl] / youtube_dl / utils.py
index c761ea22a4580216bb2484bd08ec7e8de1d724e4..672ce05ea17b9d0ab9c009c383810ff54a97dd10 100644 (file)
@@ -56,7 +56,7 @@ from .compat import (
 compiled_regex_type = type(re.compile(''))
 
 std_headers = {
 compiled_regex_type = type(re.compile(''))
 
 std_headers = {
-    'User-Agent': 'Mozilla/5.0 (X11; Linux x86_64; rv:10.0) Gecko/20150101 Firefox/20.0 (Chrome)',
+    'User-Agent': 'Mozilla/5.0 (X11; Linux x86_64; rv:10.0) Gecko/20150101 Firefox/44.0 (Chrome)',
     'Accept-Charset': 'ISO-8859-1,utf-8;q=0.7,*;q=0.7',
     'Accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8',
     'Accept-Encoding': 'gzip, deflate',
     'Accept-Charset': 'ISO-8859-1,utf-8;q=0.7,*;q=0.7',
     'Accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8',
     'Accept-Encoding': 'gzip, deflate',
@@ -70,6 +70,21 @@ ENGLISH_MONTH_NAMES = [
     'January', 'February', 'March', 'April', 'May', 'June',
     'July', 'August', 'September', 'October', 'November', 'December']
 
     'January', 'February', 'March', 'April', 'May', 'June',
     'July', 'August', 'September', 'October', 'November', 'December']
 
+KNOWN_EXTENSIONS = (
+    'mp4', 'm4a', 'm4p', 'm4b', 'm4r', 'm4v', 'aac',
+    'flv', 'f4v', 'f4a', 'f4b',
+    'webm', 'ogg', 'ogv', 'oga', 'ogx', 'spx', 'opus',
+    'mkv', 'mka', 'mk3d',
+    'avi', 'divx',
+    'mov',
+    'asf', 'wmv', 'wma',
+    '3gp', '3g2',
+    'mp3',
+    'flac',
+    'ape',
+    'wav',
+    'f4f', 'f4m', 'm3u8', 'smil')
+
 
 def preferredencoding():
     """Get preferred encoding.
 
 def preferredencoding():
     """Get preferred encoding.
@@ -179,10 +194,19 @@ def xpath_with_ns(path, ns_map):
 
 
 def xpath_element(node, xpath, name=None, fatal=False, default=NO_DEFAULT):
 
 
 def xpath_element(node, xpath, name=None, fatal=False, default=NO_DEFAULT):
-    if sys.version_info < (2, 7):  # Crazy 2.6
-        xpath = xpath.encode('ascii')
+    def _find_xpath(xpath):
+        if sys.version_info < (2, 7):  # Crazy 2.6
+            xpath = xpath.encode('ascii')
+        return node.find(xpath)
+
+    if isinstance(xpath, (str, compat_str)):
+        n = _find_xpath(xpath)
+    else:
+        for xp in xpath:
+            n = _find_xpath(xp)
+            if n is not None:
+                break
 
 
-    n = node.find(xpath)
     if n is None:
         if default is not NO_DEFAULT:
             return default
     if n is None:
         if default is not NO_DEFAULT:
             return default
@@ -224,7 +248,7 @@ def xpath_attr(node, xpath, key, name=None, fatal=False, default=NO_DEFAULT):
 
 def get_element_by_id(id, html):
     """Return the content of the tag with the specified ID in the passed HTML document"""
 
 def get_element_by_id(id, html):
     """Return the content of the tag with the specified ID in the passed HTML document"""
-    return get_element_by_attribute("id", id, html)
+    return get_element_by_attribute('id', id, html)
 
 
 def get_element_by_attribute(attribute, value, html):
 
 
 def get_element_by_attribute(attribute, value, html):
@@ -357,13 +381,20 @@ def sanitize_path(s):
     if drive_or_unc:
         norm_path.pop(0)
     sanitized_path = [
     if drive_or_unc:
         norm_path.pop(0)
     sanitized_path = [
-        path_part if path_part in ['.', '..'] else re.sub('(?:[/<>:"\\|\\\\?\\*]|\.$)', '#', path_part)
+        path_part if path_part in ['.', '..'] else re.sub('(?:[/<>:"\\|\\\\?\\*]|[\s.]$)', '#', path_part)
         for path_part in norm_path]
     if drive_or_unc:
         sanitized_path.insert(0, drive_or_unc + os.path.sep)
     return os.path.join(*sanitized_path)
 
 
         for path_part in norm_path]
     if drive_or_unc:
         sanitized_path.insert(0, drive_or_unc + os.path.sep)
     return os.path.join(*sanitized_path)
 
 
+# Prepend protocol-less URLs with `http:` scheme in order to mitigate the number of
+# unwanted failures due to missing protocol
+def sanitized_Request(url, *args, **kwargs):
+    return compat_urllib_request.Request(
+        'http:%s' % url if url.startswith('//') else url, *args, **kwargs)
+
+
 def orderedSet(iterable):
     """ Remove all duplicates from the input iterable """
     res = []
 def orderedSet(iterable):
     """ Remove all duplicates from the input iterable """
     res = []
@@ -387,10 +418,14 @@ def _htmlentity_transform(entity):
             numstr = '0%s' % numstr
         else:
             base = 10
             numstr = '0%s' % numstr
         else:
             base = 10
-        return compat_chr(int(numstr, base))
+        # See https://github.com/rg3/youtube-dl/issues/7518
+        try:
+            return compat_chr(int(numstr, base))
+        except ValueError:
+            pass
 
     # Unknown entity in name, return its literal representation
 
     # Unknown entity in name, return its literal representation
-    return ('&%s;' % entity)
+    return '&%s;' % entity
 
 
 def unescapeHTML(s):
 
 
 def unescapeHTML(s):
@@ -643,6 +678,16 @@ def _create_http_connection(ydl_handler, http_class, is_https, *args, **kwargs):
     return hc
 
 
     return hc
 
 
+def handle_youtubedl_headers(headers):
+    filtered_headers = headers
+
+    if 'Youtubedl-no-compression' in filtered_headers:
+        filtered_headers = dict((k, v) for k, v in filtered_headers.items() if k.lower() != 'accept-encoding')
+        del filtered_headers['Youtubedl-no-compression']
+
+    return filtered_headers
+
+
 class YoutubeDLHandler(compat_urllib_request.HTTPHandler):
     """Handler for HTTP requests and responses.
 
 class YoutubeDLHandler(compat_urllib_request.HTTPHandler):
     """Handler for HTTP requests and responses.
 
@@ -650,7 +695,7 @@ class YoutubeDLHandler(compat_urllib_request.HTTPHandler):
     the standard headers to every HTTP request and handles gzipped and
     deflated responses from web servers. If compression is to be avoided in
     a particular request, the original request in the program code only has
     the standard headers to every HTTP request and handles gzipped and
     deflated responses from web servers. If compression is to be avoided in
     a particular request, the original request in the program code only has
-    to include the HTTP header "Youtubedl-No-Compression", which will be
+    to include the HTTP header "Youtubedl-no-compression", which will be
     removed before making the real request.
 
     Part of this code was copied from:
     removed before making the real request.
 
     Part of this code was copied from:
@@ -711,10 +756,8 @@ class YoutubeDLHandler(compat_urllib_request.HTTPHandler):
             # The dict keys are capitalized because of this bug by urllib
             if h.capitalize() not in req.headers:
                 req.add_header(h, v)
             # The dict keys are capitalized because of this bug by urllib
             if h.capitalize() not in req.headers:
                 req.add_header(h, v)
-        if 'Youtubedl-no-compression' in req.headers:
-            if 'Accept-encoding' in req.headers:
-                del req.headers['Accept-encoding']
-            del req.headers['Youtubedl-no-compression']
+
+        req.headers = handle_youtubedl_headers(req.headers)
 
         if sys.version_info < (2, 7) and '#' in req.get_full_url():
             # Python 2.6 is brain-dead when it comes to fragments
 
         if sys.version_info < (2, 7) and '#' in req.get_full_url():
             # Python 2.6 is brain-dead when it comes to fragments
@@ -745,11 +788,13 @@ class YoutubeDLHandler(compat_urllib_request.HTTPHandler):
                     raise original_ioerror
             resp = self.addinfourl_wrapper(uncompressed, old_resp.headers, old_resp.url, old_resp.code)
             resp.msg = old_resp.msg
                     raise original_ioerror
             resp = self.addinfourl_wrapper(uncompressed, old_resp.headers, old_resp.url, old_resp.code)
             resp.msg = old_resp.msg
+            del resp.headers['Content-encoding']
         # deflate
         if resp.headers.get('Content-encoding', '') == 'deflate':
             gz = io.BytesIO(self.deflate(resp.read()))
             resp = self.addinfourl_wrapper(gz, old_resp.headers, old_resp.url, old_resp.code)
             resp.msg = old_resp.msg
         # deflate
         if resp.headers.get('Content-encoding', '') == 'deflate':
             gz = io.BytesIO(self.deflate(resp.read()))
             resp = self.addinfourl_wrapper(gz, old_resp.headers, old_resp.url, old_resp.code)
             resp.msg = old_resp.msg
+            del resp.headers['Content-encoding']
         # Percent-encode redirect URL of Location HTTP header to satisfy RFC 3986 (see
         # https://github.com/rg3/youtube-dl/issues/6457).
         if 300 <= resp.code < 400:
         # Percent-encode redirect URL of Location HTTP header to satisfy RFC 3986 (see
         # https://github.com/rg3/youtube-dl/issues/6457).
         if 300 <= resp.code < 400:
@@ -815,9 +860,11 @@ def parse_iso8601(date_str, delimiter='T', timezone=None):
     if date_str is None:
         return None
 
     if date_str is None:
         return None
 
+    date_str = re.sub(r'\.[0-9]+', '', date_str)
+
     if timezone is None:
         m = re.search(
     if timezone is None:
         m = re.search(
-            r'(\.[0-9]+)?(?:Z$| ?(?P<sign>\+|-)(?P<hours>[0-9]{2}):?(?P<minutes>[0-9]{2})$)',
+            r'(?:Z$| ?(?P<sign>\+|-)(?P<hours>[0-9]{2}):?(?P<minutes>[0-9]{2})$)',
             date_str)
         if not m:
             timezone = datetime.timedelta()
             date_str)
         if not m:
             timezone = datetime.timedelta()
@@ -830,9 +877,12 @@ def parse_iso8601(date_str, delimiter='T', timezone=None):
                 timezone = datetime.timedelta(
                     hours=sign * int(m.group('hours')),
                     minutes=sign * int(m.group('minutes')))
                 timezone = datetime.timedelta(
                     hours=sign * int(m.group('hours')),
                     minutes=sign * int(m.group('minutes')))
-    date_format = '%Y-%m-%d{0}%H:%M:%S'.format(delimiter)
-    dt = datetime.datetime.strptime(date_str, date_format) - timezone
-    return calendar.timegm(dt.timetuple())
+    try:
+        date_format = '%Y-%m-%d{0}%H:%M:%S'.format(delimiter)
+        dt = datetime.datetime.strptime(date_str, date_format) - timezone
+        return calendar.timegm(dt.timetuple())
+    except ValueError:
+        pass
 
 
 def unified_strdate(date_str, day_first=True):
 
 
 def unified_strdate(date_str, day_first=True):
@@ -897,7 +947,8 @@ def unified_strdate(date_str, day_first=True):
         timetuple = email.utils.parsedate_tz(date_str)
         if timetuple:
             upload_date = datetime.datetime(*timetuple[:6]).strftime('%Y%m%d')
         timetuple = email.utils.parsedate_tz(date_str)
         if timetuple:
             upload_date = datetime.datetime(*timetuple[:6]).strftime('%Y%m%d')
-    return upload_date
+    if upload_date is not None:
+        return compat_str(upload_date)
 
 
 def determine_ext(url, default_ext='unknown_video'):
 
 
 def determine_ext(url, default_ext='unknown_video'):
@@ -906,6 +957,9 @@ def determine_ext(url, default_ext='unknown_video'):
     guess = url.partition('?')[0].rpartition('.')[2]
     if re.match(r'^[A-Za-z0-9]+$', guess):
         return guess
     guess = url.partition('?')[0].rpartition('.')[2]
     if re.match(r'^[A-Za-z0-9]+$', guess):
         return guess
+    # Try extract ext from URLs like http://example.com/foo/bar.mp4/?download
+    elif guess.rstrip('/') in KNOWN_EXTENSIONS:
+        return guess.rstrip('/')
     else:
         return default_ext
 
     else:
         return default_ext
 
@@ -930,7 +984,7 @@ def date_from_str(date_str):
         if sign == '-':
             time = -time
         unit = match.group('unit')
         if sign == '-':
             time = -time
         unit = match.group('unit')
-        # A bad aproximation?
+        # A bad approximation?
         if unit == 'month':
             unit = 'day'
             time *= 30
         if unit == 'month':
             unit = 'day'
             time *= 30
@@ -940,7 +994,7 @@ def date_from_str(date_str):
         unit += 's'
         delta = datetime.timedelta(**{unit: time})
         return today + delta
         unit += 's'
         delta = datetime.timedelta(**{unit: time})
         return today + delta
-    return datetime.datetime.strptime(date_str, "%Y%m%d").date()
+    return datetime.datetime.strptime(date_str, '%Y%m%d').date()
 
 
 def hyphenate_date(date_str):
 
 
 def hyphenate_date(date_str):
@@ -1020,22 +1074,22 @@ def _windows_write_string(s, out):
 
     GetStdHandle = ctypes.WINFUNCTYPE(
         ctypes.wintypes.HANDLE, ctypes.wintypes.DWORD)(
 
     GetStdHandle = ctypes.WINFUNCTYPE(
         ctypes.wintypes.HANDLE, ctypes.wintypes.DWORD)(
-        (b"GetStdHandle", ctypes.windll.kernel32))
+        (b'GetStdHandle', ctypes.windll.kernel32))
     h = GetStdHandle(WIN_OUTPUT_IDS[fileno])
 
     WriteConsoleW = ctypes.WINFUNCTYPE(
         ctypes.wintypes.BOOL, ctypes.wintypes.HANDLE, ctypes.wintypes.LPWSTR,
         ctypes.wintypes.DWORD, ctypes.POINTER(ctypes.wintypes.DWORD),
     h = GetStdHandle(WIN_OUTPUT_IDS[fileno])
 
     WriteConsoleW = ctypes.WINFUNCTYPE(
         ctypes.wintypes.BOOL, ctypes.wintypes.HANDLE, ctypes.wintypes.LPWSTR,
         ctypes.wintypes.DWORD, ctypes.POINTER(ctypes.wintypes.DWORD),
-        ctypes.wintypes.LPVOID)((b"WriteConsoleW", ctypes.windll.kernel32))
+        ctypes.wintypes.LPVOID)((b'WriteConsoleW', ctypes.windll.kernel32))
     written = ctypes.wintypes.DWORD(0)
 
     written = ctypes.wintypes.DWORD(0)
 
-    GetFileType = ctypes.WINFUNCTYPE(ctypes.wintypes.DWORD, ctypes.wintypes.DWORD)((b"GetFileType", ctypes.windll.kernel32))
+    GetFileType = ctypes.WINFUNCTYPE(ctypes.wintypes.DWORD, ctypes.wintypes.DWORD)((b'GetFileType', ctypes.windll.kernel32))
     FILE_TYPE_CHAR = 0x0002
     FILE_TYPE_REMOTE = 0x8000
     GetConsoleMode = ctypes.WINFUNCTYPE(
         ctypes.wintypes.BOOL, ctypes.wintypes.HANDLE,
         ctypes.POINTER(ctypes.wintypes.DWORD))(
     FILE_TYPE_CHAR = 0x0002
     FILE_TYPE_REMOTE = 0x8000
     GetConsoleMode = ctypes.WINFUNCTYPE(
         ctypes.wintypes.BOOL, ctypes.wintypes.HANDLE,
         ctypes.POINTER(ctypes.wintypes.DWORD))(
-        (b"GetConsoleMode", ctypes.windll.kernel32))
+        (b'GetConsoleMode', ctypes.windll.kernel32))
     INVALID_HANDLE_VALUE = ctypes.wintypes.DWORD(-1).value
 
     def not_a_console(handle):
     INVALID_HANDLE_VALUE = ctypes.wintypes.DWORD(-1).value
 
     def not_a_console(handle):
@@ -1253,7 +1307,7 @@ def parse_filesize(s):
     if s is None:
         return None
 
     if s is None:
         return None
 
-    # The lower-case forms are of course incorrect and inofficial,
+    # The lower-case forms are of course incorrect and unofficial,
     # but we support those too
     _UNIT_TABLE = {
         'B': 1,
     # but we support those too
     _UNIT_TABLE = {
         'B': 1,
@@ -1333,7 +1387,7 @@ def fix_xml_ampersands(xml_str):
 def setproctitle(title):
     assert isinstance(title, compat_str)
     try:
 def setproctitle(title):
     assert isinstance(title, compat_str)
     try:
-        libc = ctypes.cdll.LoadLibrary("libc.so.6")
+        libc = ctypes.cdll.LoadLibrary('libc.so.6')
     except OSError:
         return
     title_bytes = title.encode('utf-8')
     except OSError:
         return
     title_bytes = title.encode('utf-8')
@@ -1357,6 +1411,15 @@ def remove_end(s, end):
     return s
 
 
     return s
 
 
+def remove_quotes(s):
+    if s is None or len(s) < 2:
+        return s
+    for quote in ('"', "'", ):
+        if s[0] == quote and s[-1] == quote:
+            return s[1:-1]
+    return s
+
+
 def url_basename(url):
     path = compat_urlparse.urlparse(url).path
     return path.strip('/').split('/')[-1]
 def url_basename(url):
     path = compat_urlparse.urlparse(url).path
     return path.strip('/').split('/')[-1]
@@ -1364,7 +1427,7 @@ def url_basename(url):
 
 class HEADRequest(compat_urllib_request.Request):
     def get_method(self):
 
 class HEADRequest(compat_urllib_request.Request):
     def get_method(self):
-        return "HEAD"
+        return 'HEAD'
 
 
 def int_or_none(v, scale=1, default=None, get_attr=None, invscale=1):
 
 
 def int_or_none(v, scale=1, default=None, get_attr=None, invscale=1):
@@ -1649,7 +1712,23 @@ def urlencode_postdata(*args, **kargs):
 
 
 def encode_dict(d, encoding='utf-8'):
 
 
 def encode_dict(d, encoding='utf-8'):
-    return dict((k.encode(encoding), v.encode(encoding)) for k, v in d.items())
+    def encode(v):
+        return v.encode(encoding) if isinstance(v, compat_basestring) else v
+    return dict((encode(k), encode(v)) for k, v in d.items())
+
+
+def dict_get(d, key_or_keys, default=None, skip_false_values=True):
+    if isinstance(key_or_keys, (list, tuple)):
+        for key in key_or_keys:
+            if key not in d or d[key] is None or skip_false_values and not d[key]:
+                continue
+            return d[key]
+        return default
+    return d.get(key_or_keys, default)
+
+
+def encode_compat_str(string, encoding=preferredencoding(), errors='strict'):
+    return string if isinstance(string, compat_str) else compat_str(string, encoding, errors)
 
 
 US_RATINGS = {
 
 
 US_RATINGS = {
@@ -1665,12 +1744,12 @@ def parse_age_limit(s):
     if s is None:
         return None
     m = re.match(r'^(?P<age>\d{1,2})\+?$', s)
     if s is None:
         return None
     m = re.match(r'^(?P<age>\d{1,2})\+?$', s)
-    return int(m.group('age')) if m else US_RATINGS.get(s, None)
+    return int(m.group('age')) if m else US_RATINGS.get(s)
 
 
 def strip_jsonp(code):
     return re.sub(
 
 
 def strip_jsonp(code):
     return re.sub(
-        r'(?s)^[a-zA-Z0-9_]+\s*\(\s*(.*)\);?\s*?(?://[^\n]*)*$', r'\1', code)
+        r'(?s)^[a-zA-Z0-9_.]+\s*\(\s*(.*)\);?\s*?(?://[^\n]*)*$', r'\1', code)
 
 
 def js_to_json(code):
 
 
 def js_to_json(code):
@@ -1746,13 +1825,24 @@ def args_to_str(args):
     return ' '.join(shlex_quote(a) for a in args)
 
 
     return ' '.join(shlex_quote(a) for a in args)
 
 
+def error_to_compat_str(err):
+    err_str = str(err)
+    # On python 2 error byte string must be decoded with proper
+    # encoding rather than ascii
+    if sys.version_info[0] < 3:
+        err_str = err_str.decode(preferredencoding())
+    return err_str
+
+
 def mimetype2ext(mt):
     _, _, res = mt.rpartition('/')
 
     return {
 def mimetype2ext(mt):
     _, _, res = mt.rpartition('/')
 
     return {
-        'x-ms-wmv': 'wmv',
-        'x-mp4-fragmented': 'mp4',
+        '3gpp': '3gp',
         'ttml+xml': 'ttml',
         'ttml+xml': 'ttml',
+        'x-flv': 'flv',
+        'x-mp4-fragmented': 'mp4',
+        'x-ms-wmv': 'wmv',
     }.get(res, res)
 
 
     }.get(res, res)
 
 
@@ -1916,15 +2006,15 @@ def match_filter_func(filter_str):
 
 def parse_dfxp_time_expr(time_expr):
     if not time_expr:
 
 def parse_dfxp_time_expr(time_expr):
     if not time_expr:
-        return 0.0
+        return
 
     mobj = re.match(r'^(?P<time_offset>\d+(?:\.\d+)?)s?$', time_expr)
     if mobj:
         return float(mobj.group('time_offset'))
 
 
     mobj = re.match(r'^(?P<time_offset>\d+(?:\.\d+)?)s?$', time_expr)
     if mobj:
         return float(mobj.group('time_offset'))
 
-    mobj = re.match(r'^(\d+):(\d\d):(\d\d(?:\.\d+)?)$', time_expr)
+    mobj = re.match(r'^(\d+):(\d\d):(\d\d(?:(?:\.|:)\d+)?)$', time_expr)
     if mobj:
     if mobj:
-        return 3600 * int(mobj.group(1)) + 60 * int(mobj.group(2)) + float(mobj.group(3))
+        return 3600 * int(mobj.group(1)) + 60 * int(mobj.group(2)) + float(mobj.group(3).replace(':', '.'))
 
 
 def srt_subtitles_timecode(seconds):
 
 
 def srt_subtitles_timecode(seconds):
@@ -1937,20 +2027,27 @@ def dfxp2srt(dfxp_data):
         'ttaf1': 'http://www.w3.org/2006/10/ttaf1',
     })
 
         'ttaf1': 'http://www.w3.org/2006/10/ttaf1',
     })
 
-    def parse_node(node):
-        str_or_empty = functools.partial(str_or_none, default='')
+    class TTMLPElementParser(object):
+        out = ''
 
 
-        out = str_or_empty(node.text)
+        def start(self, tag, attrib):
+            if tag in (_x('ttml:br'), _x('ttaf1:br'), 'br'):
+                self.out += '\n'
 
 
-        for child in node:
-            if child.tag in (_x('ttml:br'), _x('ttaf1:br'), 'br'):
-                out += '\n' + str_or_empty(child.tail)
-            elif child.tag in (_x('ttml:span'), _x('ttaf1:span'), 'span'):
-                out += str_or_empty(parse_node(child))
-            else:
-                out += str_or_empty(xml.etree.ElementTree.tostring(child))
+        def end(self, tag):
+            pass
+
+        def data(self, data):
+            self.out += data
 
 
-        return out
+        def close(self):
+            return self.out.strip()
+
+    def parse_node(node):
+        target = TTMLPElementParser()
+        parser = xml.etree.ElementTree.XMLParser(target=target)
+        parser.feed(xml.etree.ElementTree.tostring(node))
+        return parser.close()
 
     dfxp = compat_etree_fromstring(dfxp_data.encode('utf-8'))
     out = []
 
     dfxp = compat_etree_fromstring(dfxp_data.encode('utf-8'))
     out = []
@@ -1960,10 +2057,15 @@ def dfxp2srt(dfxp_data):
         raise ValueError('Invalid dfxp/TTML subtitle')
 
     for para, index in zip(paras, itertools.count(1)):
         raise ValueError('Invalid dfxp/TTML subtitle')
 
     for para, index in zip(paras, itertools.count(1)):
-        begin_time = parse_dfxp_time_expr(para.attrib['begin'])
+        begin_time = parse_dfxp_time_expr(para.attrib.get('begin'))
         end_time = parse_dfxp_time_expr(para.attrib.get('end'))
         end_time = parse_dfxp_time_expr(para.attrib.get('end'))
+        dur = parse_dfxp_time_expr(para.attrib.get('dur'))
+        if begin_time is None:
+            continue
         if not end_time:
         if not end_time:
-            end_time = begin_time + parse_dfxp_time_expr(para.attrib['dur'])
+            if not dur:
+                continue
+            end_time = begin_time + dur
         out.append('%d\n%s --> %s\n%s\n\n' % (
             index,
             srt_subtitles_timecode(begin_time),
         out.append('%d\n%s --> %s\n%s\n\n' % (
             index,
             srt_subtitles_timecode(begin_time),