bazarr/libs/pysubs2/subrip.py

165 lines
6.9 KiB
Python

import re
from .formatbase import FormatBase
from .ssaevent import SSAEvent
from .ssastyle import SSAStyle
from .substation import parse_tags
from .exceptions import ContentNotUsable
from .time import ms_to_times, make_time, TIMESTAMP, timestamp_to_ms
#: Largest timestamp allowed in SubRip, ie. 99:59:59,999.
MAX_REPRESENTABLE_TIME = make_time(h=100) - 1
class SubripFormat(FormatBase):
"""SubRip Text (SRT) subtitle format implementation"""
TIMESTAMP = TIMESTAMP
@staticmethod
def ms_to_timestamp(ms: int) -> str:
"""Convert ms to 'HH:MM:SS,mmm'"""
# XXX throw on overflow/underflow?
if ms < 0: ms = 0
if ms > MAX_REPRESENTABLE_TIME: ms = MAX_REPRESENTABLE_TIME
h, m, s, ms = ms_to_times(ms)
return "%02d:%02d:%02d,%03d" % (h, m, s, ms)
@staticmethod
def timestamp_to_ms(groups):
return timestamp_to_ms(groups)
@classmethod
def guess_format(cls, text):
"""See :meth:`pysubs2.formats.FormatBase.guess_format()`"""
if "[Script Info]" in text or "[V4+ Styles]" in text:
# disambiguation vs. SSA/ASS
return None
if text.lstrip().startswith("WEBVTT"):
# disambiguation vs. WebVTT
return None
for line in text.splitlines():
if len(cls.TIMESTAMP.findall(line)) == 2:
return "srt"
@classmethod
def from_file(cls, subs, fp, format_, keep_html_tags=False, keep_unknown_html_tags=False, **kwargs):
"""
See :meth:`pysubs2.formats.FormatBase.from_file()`
Supported tags:
- ``<i>``
- ``<u>``
- ``<s>``
- ``<b>``
Keyword args:
keep_html_tags: If True, all HTML tags will be kept as-is instead of being
converted to SubStation tags (eg. you will get ``<i>example</i>`` instead of ``{\\i1}example{\\i0}``).
Setting this to True overrides the ``keep_unknown_html_tags`` option.
keep_unknown_html_tags: If True, supported HTML tags will be converted
to SubStation tags and any other HTML tags will be kept as-is
(eg. you would get ``<blink>example {\\i1}text{\\i0}</blink>``).
If False, these other HTML tags will be stripped from output
(in the previous example, you would get only ``example {\\i1}text{\\i0}``).
"""
timestamps = [] # (start, end)
following_lines = [] # contains lists of lines following each timestamp
for line in fp:
stamps = cls.TIMESTAMP.findall(line)
if len(stamps) == 2: # timestamp line
start, end = map(cls.timestamp_to_ms, stamps)
timestamps.append((start, end))
following_lines.append([])
else:
if timestamps:
following_lines[-1].append(line)
def prepare_text(lines):
# Handle the "happy" empty subtitle case, which is timestamp line followed by blank line(s)
# followed by number line and timestamp line of the next subtitle. Fixes issue #11.
if (len(lines) >= 2
and all(re.match(r"\s*$", line) for line in lines[:-1])
and re.match(r"\s*\d+\s*$", lines[-1])):
return ""
# Handle the general case.
s = "".join(lines).strip()
s = re.sub(r"\n+ *\d+ *$", "", s) # strip number of next subtitle
if not keep_html_tags:
s = re.sub(r"< *i *>", r"{\\i1}", s)
s = re.sub(r"< */ *i *>", r"{\\i0}", s)
s = re.sub(r"< *s *>", r"{\\s1}", s)
s = re.sub(r"< */ *s *>", r"{\\s0}", s)
s = re.sub(r"< *u *>", r"{\\u1}", s)
s = re.sub(r"< */ *u *>", r"{\\u0}", s)
s = re.sub(r"< *b *>", r"{\\b1}", s)
s = re.sub(r"< */ *b *>", r"{\\b0}", s)
if not (keep_html_tags or keep_unknown_html_tags):
s = re.sub(r"< */? *[a-zA-Z][^>]*>", "", s) # strip other HTML tags
s = re.sub(r"\n", r"\\N", s) # convert newlines
return s
subs.events = [SSAEvent(start=start, end=end, text=prepare_text(lines))
for (start, end), lines in zip(timestamps, following_lines)]
@classmethod
def to_file(cls, subs, fp, format_, apply_styles=True, keep_ssa_tags=False, **kwargs):
"""
See :meth:`pysubs2.formats.FormatBase.to_file()`
Italic, underline and strikeout styling is supported.
Keyword args:
apply_styles: If False, do not write any styling (ignore line style
and override tags).
keep_ssa_tags: If True, instead of trying to convert inline override
tags to HTML (as supported by SRT), any inline tags will be passed
to output (eg. ``{\\an7}``, which would be otherwise stripped;
or ``{\\b1}`` instead of ``<b>``). Whitespace tags ``\\h``, ``\\n``
and ``\\N`` will always be converted to whitespace regardless of
this option. In the current implementation, enabling this option
disables processing of line styles - you will get inline tags but
if for example line's style is italic you will not get ``{\\i1}``
at the beginning of the line. (Since this option is mostly useful
for dealing with non-standard SRT files, ie. both input and output
is SRT which doesn't use line styles - this shouldn't be much
of an issue in practice.)
"""
def prepare_text(text: str, style: SSAStyle):
text = text.replace(r"\h", " ")
text = text.replace(r"\n", "\n")
text = text.replace(r"\N", "\n")
body = []
if keep_ssa_tags:
body.append(text)
else:
for fragment, sty in parse_tags(text, style, subs.styles):
if apply_styles:
if sty.italic: fragment = "<i>%s</i>" % fragment
if sty.underline: fragment = "<u>%s</u>" % fragment
if sty.strikeout: fragment = "<s>%s</s>" % fragment
if sty.drawing: raise ContentNotUsable
body.append(fragment)
return re.sub("\n+", "\n", "".join(body).strip())
visible_lines = (line for line in subs if not line.is_comment)
lineno = 1
for line in visible_lines:
start = cls.ms_to_timestamp(line.start)
end = cls.ms_to_timestamp(line.end)
try:
text = prepare_text(line.text, subs.styles.get(line.style, SSAStyle.DEFAULT_STYLE))
except ContentNotUsable:
continue
print("%d" % lineno, file=fp) # Python 2.7 compat
print(start, "-->", end, file=fp)
print(text, end="\n\n", file=fp)
lineno += 1