mirror of
https://github.com/jxxghp/MoviePilot.git
synced 2026-11-13 00:59:01 +08:00
262 lines
9.4 KiB
Python
262 lines
9.4 KiB
Python
"""把 AMLL 的主唱 TTML 时轴转换为宿主歌词候选。"""
|
||
|
||
import re
|
||
from dataclasses import dataclass, replace
|
||
from io import StringIO
|
||
from typing import Optional
|
||
|
||
from lxml import etree
|
||
from ruamel.yaml import YAML
|
||
|
||
from app.domain.context import MusicLyrics
|
||
|
||
_TTML = "{http://www.w3.org/ns/ttml}"
|
||
_METADATA = "{http://www.w3.org/ns/ttml#metadata}"
|
||
_STYLING = "{http://www.w3.org/ns/ttml#styling}"
|
||
_XML = "{http://www.w3.org/XML/1998/namespace}"
|
||
_MAX_BYTES = 1024 * 1024
|
||
_MAX_DEPTH = 20
|
||
_MAX_NODES = 10000
|
||
_TIMESTAMP = re.compile(r"(?:[0-9]+:){0,2}[0-9]+(?:\.[0-9]+)?\Z")
|
||
_AUXILIARY_ROLES = frozenset({"x-translation", "x-roman", "x-bg"})
|
||
_RUBY_ANNOTATIONS = frozenset({"text", "textContainer", "delimiter"})
|
||
|
||
|
||
@dataclass(frozen=True)
|
||
class _Fragment:
|
||
"""保存主唱文本片段及来源明确提供的绝对毫秒时轴。"""
|
||
|
||
text: str
|
||
start: Optional[int] = None
|
||
end: Optional[int] = None
|
||
|
||
|
||
@dataclass(frozen=True)
|
||
class _Line:
|
||
"""保留完整主唱句子，只有全部词语有可靠时轴时才提供逐词数据。"""
|
||
|
||
text: str
|
||
start: Optional[int]
|
||
end: Optional[int]
|
||
words: tuple[_Fragment, ...]
|
||
|
||
|
||
def _load_document(content: str) -> Optional[etree._Element]:
|
||
"""限制外部 XML 的体积、结构和实体能力，解析失败时拒绝整个文档。"""
|
||
if not content or len(content) > _MAX_BYTES:
|
||
return None
|
||
try:
|
||
data = content.encode("utf-8")
|
||
if len(data) > _MAX_BYTES:
|
||
return None
|
||
parser = etree.XMLParser(
|
||
encoding="utf-8", resolve_entities=False, no_network=True,
|
||
load_dtd=False, remove_comments=True, remove_pis=True,
|
||
)
|
||
root = etree.fromstring(data, parser=parser)
|
||
except (etree.XMLSyntaxError, UnicodeError, ValueError):
|
||
return None
|
||
if root.tag != f"{_TTML}tt" or root.getroottree().docinfo.doctype:
|
||
return None
|
||
return root if _bounded_tree(root) else None
|
||
|
||
|
||
def _bounded_tree(root: etree._Element) -> bool:
|
||
"""按开始和结束事件计算深度及节点数，限制后续递归转换的资源消耗。"""
|
||
depth = 0
|
||
count = 0
|
||
for event, _element in etree.iterwalk(root, events=("start", "end")):
|
||
if event == "end":
|
||
depth -= 1
|
||
continue
|
||
depth += 1
|
||
count += 1
|
||
if depth > _MAX_DEPTH or count > _MAX_NODES:
|
||
return False
|
||
return True
|
||
|
||
|
||
def _timestamp(value: Optional[str]) -> Optional[int]:
|
||
"""解析 AMLL 的秒、分秒或时分秒格式，不接受单位后缀和帧计时。"""
|
||
text = (value or "").strip()
|
||
if not text or len(text) > 32 or not _TIMESTAMP.fullmatch(text):
|
||
return None
|
||
integer, _, fraction = text.partition(".")
|
||
seconds = 0
|
||
for part in integer.split(":"):
|
||
seconds = seconds * 60 + int(part)
|
||
# 使用十进制整数截取毫秒，避免浮点数把已有时轴偏移一个毫秒。
|
||
return seconds * 1000 + int((fraction + "000")[:3])
|
||
|
||
|
||
def _time_range(element: etree._Element) -> tuple[Optional[int], Optional[int]]:
|
||
"""读取绝对起止时轴；AMLL 子节点时间不叠加父节点的开始时间。"""
|
||
start = _timestamp(element.get("begin"))
|
||
end = _timestamp(element.get("end"))
|
||
if start is None or end is None or end <= start:
|
||
return None, None
|
||
return start, end
|
||
|
||
|
||
def _is_auxiliary(element: etree._Element) -> bool:
|
||
"""排除翻译、音译、背景人声以及 Ruby 注音文本，保留主唱和 Ruby 基字。"""
|
||
roles = set((element.get(f"{_METADATA}role") or "").split())
|
||
return bool(roles & _AUXILIARY_ROLES) or (
|
||
element.get(f"{_STYLING}ruby") in _RUBY_ANNOTATIONS
|
||
)
|
||
|
||
|
||
def _text(value: Optional[str]) -> str:
|
||
"""忽略纯换行缩进，同时保留词内、词尾和同行片段间的必要空格。"""
|
||
if not value or ("\n" in value and not value.strip()):
|
||
return ""
|
||
return re.sub(r"\s+", " ", value)
|
||
|
||
|
||
def _fragments(element: etree._Element) -> list[_Fragment]:
|
||
"""按 XML 混合内容顺序提取主唱片段，不把排除节点的正文混入歌词。"""
|
||
parts = [_Fragment(_text(element.text))]
|
||
for child in element:
|
||
if not _is_auxiliary(child):
|
||
if child.tag == f"{_TTML}span":
|
||
parts.extend(_span_fragments(child))
|
||
elif child.tag == f"{_TTML}br":
|
||
parts.append(_Fragment(" "))
|
||
parts.append(_Fragment(_text(child.tail)))
|
||
return [part for part in parts if part.text]
|
||
|
||
|
||
def _span_fragments(element: etree._Element) -> list[_Fragment]:
|
||
"""保留最细的可用词时轴，纯样式嵌套则归入外层已有的词时轴。"""
|
||
parts = _fragments(element)
|
||
start, end = _time_range(element)
|
||
if start is None or any(part.start is not None for part in parts):
|
||
return parts
|
||
text = "".join(part.text for part in parts)
|
||
return [_Fragment(text, start, end)] if text else []
|
||
|
||
|
||
def _complete_words(parts: list[_Fragment]) -> tuple[_Fragment, ...]:
|
||
"""仅在主唱文本完整受词时轴覆盖时生成逐词列表，并保留词间空白。"""
|
||
words: list[_Fragment] = []
|
||
for part in parts:
|
||
if not part.text.strip():
|
||
if words:
|
||
words[-1] = replace(words[-1], text=words[-1].text + part.text)
|
||
elif part.start is None or part.end is None:
|
||
return ()
|
||
else:
|
||
words.append(part)
|
||
if words:
|
||
words[0] = replace(words[0], text=words[0].text.lstrip())
|
||
words[-1] = replace(words[-1], text=words[-1].text.rstrip())
|
||
return tuple(words)
|
||
|
||
|
||
def _line(element: etree._Element) -> Optional[_Line]:
|
||
"""构造完整歌词行，缺少行时间时只从完整逐词时轴恢复行范围。"""
|
||
parts = _fragments(element)
|
||
text = "".join(part.text for part in parts).strip()
|
||
if not text:
|
||
return None
|
||
words = _complete_words(parts)
|
||
start, end = _time_range(element)
|
||
if not element.get("begin") and not element.get("end") and words:
|
||
start = min(word.start for word in words if word.start is not None)
|
||
end = max(word.end for word in words if word.end is not None)
|
||
if not _words_fit_line(words, start, end):
|
||
words = ()
|
||
return _Line(text, start, end, words)
|
||
|
||
|
||
def _words_fit_line(
|
||
words: tuple[_Fragment, ...], start: Optional[int], end: Optional[int],
|
||
) -> bool:
|
||
"""只保留完全位于行时间范围内的逐词时轴，不夹断来源时间。"""
|
||
if start is None or end is None:
|
||
return False
|
||
return all(
|
||
word.start is not None and word.end is not None
|
||
and start <= word.start < word.end <= end
|
||
for word in words
|
||
)
|
||
|
||
|
||
def _main_lines(body: etree._Element) -> list[_Line]:
|
||
"""按正文顺序读取歌词行，同时排除整个辅助轨道容器下的行。"""
|
||
lines = []
|
||
for element in body.iter(f"{_TTML}p"):
|
||
if _is_auxiliary(element) or any(
|
||
_is_auxiliary(parent) for parent in element.iterancestors()
|
||
):
|
||
continue
|
||
line = _line(element)
|
||
if line:
|
||
lines.append(line)
|
||
return lines
|
||
|
||
|
||
def _line_payload(line: _Line) -> dict[str, object]:
|
||
"""生成 Lyricsfile 1.0 行结构，仅在有效逐词时轴存在时写入 words。"""
|
||
payload: dict[str, object] = {
|
||
"start_ms": line.start,
|
||
"end_ms": line.end,
|
||
"text": line.text,
|
||
}
|
||
if line.words:
|
||
payload["words"] = [
|
||
{"start_ms": word.start, "end_ms": word.end, "text": word.text}
|
||
for word in line.words
|
||
]
|
||
return payload
|
||
|
||
|
||
def parse_lyrics(
|
||
content: str, *, title: str, artist: str, provider_id: str, match_score: int,
|
||
) -> Optional[MusicLyrics]:
|
||
"""转换已匹配的 AMLL TTML；不完整行时轴整份降为纯文本且不推测音轨时长。"""
|
||
root = _load_document(content)
|
||
if root is None or not title.strip() or not artist.strip():
|
||
return None
|
||
body = root.find(f"{_TTML}body")
|
||
if body is None:
|
||
return None
|
||
lines = _main_lines(body)
|
||
if not lines:
|
||
return None
|
||
language = root.get(f"{_XML}lang") or None
|
||
lyrics = MusicLyrics(
|
||
provider="amll", provider_id=provider_id, match_score=match_score,
|
||
language=language,
|
||
)
|
||
if any(line.start is None or line.end is None for line in lines):
|
||
lyrics.plain_lyrics = "\n".join(line.text for line in lines)
|
||
return lyrics
|
||
payload: dict[str, object] = {
|
||
"version": "1.0",
|
||
"metadata": {"title": title, "artist": artist, "language": language},
|
||
"lines": [_line_payload(line) for line in lines],
|
||
}
|
||
serialized = _serialize_payload(payload)
|
||
if len(serialized.encode("utf-8")) > _MAX_BYTES:
|
||
return None
|
||
return _lyricsfile_result(lyrics, serialized)
|
||
|
||
|
||
def _serialize_payload(payload: dict[str, object]) -> str:
|
||
"""使用已锁定且带类型声明的安全 YAML 序列化器生成标准 Lyricsfile。"""
|
||
serializer = YAML(typ="safe")
|
||
# 宿主使用 YAML 1.1 读者；按同一规则引用 No、on 等歌词，避免被解析为布尔值。
|
||
serializer.version = (1, 1)
|
||
serializer.allow_unicode = True
|
||
serializer.default_flow_style = False
|
||
with StringIO() as stream:
|
||
serializer.dump(payload, stream)
|
||
return stream.getvalue()
|
||
|
||
|
||
def _lyricsfile_result(lyrics: MusicLyrics, serialized: str) -> Optional[MusicLyrics]:
|
||
"""通过宿主模型校验并派生 LRC 与纯文本，拒绝不能安全派生的输出。"""
|
||
result = replace(lyrics, lyricsfile=serialized)
|
||
return result if result.content else None
|