aboutsummaryrefslogtreecommitdiff
path: root/app/converter
diff options
context:
space:
mode:
Diffstat (limited to 'app/converter')
-rw-r--r--app/converter/chunking.py400
-rw-r--r--app/converter/config.py7
-rw-r--r--app/converter/converter.py36
3 files changed, 412 insertions, 31 deletions
diff --git a/app/converter/chunking.py b/app/converter/chunking.py
index 9ef6a5d..0ffaa21 100644
--- a/app/converter/chunking.py
+++ b/app/converter/chunking.py
@@ -8,32 +8,346 @@ from . import config
logger = logging.getLogger(__name__)
+# Smart-chunking tuning, as fractions of the word limit (not exposed as
+# settings): once a smart chunk crosses the target it ends at the next
+# clean boundary, so most chunks land between the target and the limit
+# with some headroom under the configured size. When the next sentence
+# will not fit the running chunk, the break retreats to the previous
+# boundary that is clean and at least the floor, so a quotation is not
+# severed when a later clean boundary exists nearby.
+_TARGET_RATIO = 0.85
+_FLOOR_RATIO = 0.7
+# A single token with no whitespace cannot be broken at a word
+# boundary; if such a token runs longer than this many characters per
+# allowed word it is sliced at the hard character cap (a last-resort
+# bound for punctuation-free input such as some CJK text or damage from
+# text extraction).
+_MAX_CHARS_PER_WORD = 8
-def split_into_chunks(text: str, max_words: Optional[int] = None) -> List[str]:
- """Split text into chunks of at most ``max_words`` words.
+_ABBREVIATIONS = frozenset(
+ "mr mrs ms miss dr prof rev hon pres gov sen rep capt lt col gen "
+ "sgt maj cpl pvt jr sr st mt vs etc eg ie aka fig figs no nos vol "
+ "vols ch pp p pg dept univ ave blvd rd inc ltd co corp bros apt "
+ "ste est approx min sec hrs msg mme mlle".split())
- ``max_words`` defaults to ``config.CHUNK_SIZE`` (read at call time).
- There is no ceiling beyond that setting, but note that the TTS
- servers silently truncate audio when a single generation runs too
- long without reporting an error, so very large values are at your
- own risk (see CHUNK_SIZE in app/converter/config.py).
+_EVENT = re.compile(
+ r"(?P<end>[.!?…。!?][\"'”’»)}\]]*)"
+ r"|(?P<para>\n[ \t]*\n)"
+ r"|(?P<open>[“«])"
+ r"|(?P<close>[”»])"
+ r"|(?P<straight>\")")
+
+_PARA_AFTER = re.compile(r"[ \t\r]*\n[ \t]*\n")
+
+# Scripts whose characters are not whitespace-delimited: count each one
+# as a word so a long CJK passage is bounded like English text of the
+# same spoken length instead of reading as one giant "word".
+_NON_SPACED_RUN = re.compile(r"[\u3040-\u30ff\u3400-\u4dbf\u4e00-\u9fff"
+ r"\uf900-\ufaff]")
+
+
+class _Unit:
+ """A sentence-sized piece of text plus its packing metadata.
- Splits on sentence boundaries. Sentences longer than the limit are
- split further at clause punctuation (which is kept attached for TTS
- prosody). Clause splits only happen at whitespace after punctuation,
- so tokens like "1,000,000" or "12:30" are never broken apart. A piece
- with no usable punctuation split point longer than the limit is split
- at word boundaries as a last resort: individual tokens stay intact,
- but whitespace between them is normalized.
+ ``in_quote_end`` is the quotation state after the unit's terminator
+ (double-quote open marks and closes are tracked; apostrophes do not
+ count as quotes), and ``para_after`` marks a unit that a blank line
+ follows.
"""
- if max_words is None:
- max_words = config.CHUNK_SIZE
- if max_words < 1:
- max_words = 1
- if not text.strip():
- return []
+ __slots__ = ("text", "words", "para_after", "in_quote_end")
+
+ def __init__(self, text: str, words: int, para_after: bool,
+ in_quote_end: bool):
+ self.text = text
+ self.words = words
+ self.para_after = para_after
+ self.in_quote_end = in_quote_end
+
+
+def _count_words(text: str) -> int:
+ """Words in TEXT; non-spaced-script characters each count as one."""
+ return len(text.split()) + len(_NON_SPACED_RUN.findall(text))
+
+
+def _is_abbreviation(text: str, dot: int) -> bool:
+ """True when the '.' before which a sentence split is being
+ considered belongs to an abbreviation or a name initial (Mr. St.
+ U.S. J.), where a break would fall mid-sentence."""
+ start = dot
+ while start > 0 and (text[start - 1].isalnum()
+ or text[start - 1] in ".-'’"):
+ start -= 1
+ token = text[start:dot]
+ if not token:
+ return False
+ tail = token.split(".")[-1]
+ if len(tail) == 1 and tail.isalpha():
+ return True
+ return token.lower() in _ABBREVIATIONS
+
+
+def _sentence_continues(text: str, end: int, attach: bool) -> bool:
+ """True when the text after a terminator belongs to the same unit.
+
+ Only a closing quote or an ellipsis can pull a lowercase word into
+ the unit (dialogue tags: ``“Come here!” she said.``); a plain
+ period always ends the sentence, whatever follows.
+ """
+ match = re.compile(r"\S").search(text, end)
+ if match is None:
+ return False
+ return attach and match.group().islower()
+
+
+def _scan_units(text: str) -> List[_Unit]:
+ """Split TEXT into sentence units, tracking quotes and paragraphs.
+
+ Splits at sentence terminators (.!?…) plus any closing quotes or
+ brackets that trail them, suppressing false boundaries for
+ abbreviations, initials, and lowercase continuations. Blank lines
+ close a paragraph (and reset the quotation state, so one unclosed
+ quote cannot silence clean boundaries for the rest of a book).
+ Non-whitespace content is preserved; only whitespace between
+ boundaries may be normalized.
+ """
+ units: List[_Unit] = []
+ seg_start = 0
+ in_quote = False
+ depth = 0
+
+ def emit(end: int, para_after: bool) -> None:
+ nonlocal seg_start
+ segment = text[seg_start:end]
+ seg_start = end
+ if not segment.strip():
+ return
+ units.append(_Unit(segment, _count_words(segment), para_after,
+ in_quote or depth > 0))
+
+ for match in _EVENT.finditer(text):
+ kind = match.lastgroup
+ if kind == "end":
+ run = match.group()
+ for ch in run[1:]:
+ if ch == '"':
+ in_quote = not in_quote
+ elif ch in "”»":
+ depth = max(0, depth - 1)
+ end = match.end()
+ nxt = text[end:end + 1]
+ if nxt and not nxt.isspace() \
+ and not _NON_SPACED_RUN.match(nxt):
+ continue # glued punctuation: "3.14" is not a boundary
+ if (run[0] == "." and _is_abbreviation(text, match.start())) \
+ or _sentence_continues(text, end, len(run) > 1
+ or run[0] == "…"):
+ continue
+ emit(end, _PARA_AFTER.match(text, end) is not None)
+ elif kind == "para":
+ emit(match.start(), True)
+ in_quote = False
+ depth = 0
+ elif kind == "open":
+ depth += 1
+ elif kind == "close":
+ depth = max(0, depth - 1)
+ elif kind == "straight":
+ in_quote = not in_quote
+
+ emit(len(text), False)
+ return units
+
+
+def _join(units: List[_Unit]) -> str:
+ """Join units into one chunk, keeping paragraph breaks inside it."""
+ parts: List[str] = []
+ previous = None
+ for unit in units:
+ text = unit.text.strip()
+ if not text:
+ continue
+ if parts:
+ parts.append("\n\n" if previous.para_after else " ")
+ parts.append(text)
+ previous = unit
+ return "".join(parts)
+
+
+def _retreat_point(cur: List[_Unit], floor: int) -> int:
+ """Index in CUR to break at when the next unit will not fit.
+
+ Picks the largest prefix of at least FLOOR words that ends outside
+ a quotation; failing that, the largest prefix of at least FLOOR
+ words that ends a paragraph; failing both, the whole prefix (the
+ chunk keeps as much as fits and carries the open quotation into the
+ next chunk).
+ """
+ best_clean = 0
+ best_para = 0
+ words = 0
+ for k, unit in enumerate(cur, 1):
+ words += unit.words
+ if words < floor:
+ continue
+ if not unit.in_quote_end:
+ best_clean = k
+ elif unit.para_after:
+ best_para = k
+ return best_clean or best_para or len(cur)
+
+
+def _split_oversized(text: str, max_words: int) -> List[str]:
+ """Break a sentence longer than the limit into packable pieces.
+
+ First at clause punctuation (kept attached for TTS prosody, and
+ never at commas without whitespace so tokens like "1,000,000" and
+ "12:30" survive), then at word boundaries. A token with no
+ whitespace at all is sliced at the hard character cap so a
+ punctuation-free run cannot exceed the bound.
+ """
+ parts = re.split(r"(?:(?<=[,;:])\s+|(?<=[,、;:]))", text)
+ pieces: List[str] = []
+ cap = max_words * _MAX_CHARS_PER_WORD
+ for part in parts:
+ part = part.strip()
+ if not part:
+ continue
+ if len(part) <= cap and _count_words(part) <= max_words:
+ pieces.append(part)
+ continue
+ pieces.extend(_hard_slices(part, max_words, cap))
+ return pieces
+
+
+def _hard_slices(text: str, max_words: int, cap: int) -> List[str]:
+ """Slice TEXT at word boundaries, then at CAP characters when a
+ single token has no whitespace to break at. Buffers never exceed
+ the word limit or the character cap, so every piece is packable."""
+ pieces: List[str] = []
+ buf: List[str] = []
+ buf_words = 0
+ buf_chars = 0
+ for word in text.split():
+ if len(word) > cap:
+ if buf:
+ pieces.append(" ".join(buf))
+ buf, buf_words, buf_chars = [], 0, 0
+ for start in range(0, len(word), cap):
+ pieces.append(word[start:start + cap])
+ continue
+ words = _count_words(word)
+ if buf and buf_words + words <= max_words \
+ and buf_chars + 1 + len(word) <= cap:
+ buf.append(word)
+ buf_words += words
+ buf_chars += 1 + len(word)
+ else:
+ if buf:
+ pieces.append(" ".join(buf))
+ buf, buf_words, buf_chars = [word], words, len(word)
+ if buf:
+ pieces.append(" ".join(buf))
+ return pieces
+
+
+def _joined_chars(units: List[_Unit]) -> int:
+ """The character length of the text _join would produce."""
+ total = 0
+ previous = None
+ for unit in units:
+ text = unit.text.strip()
+ if not text:
+ continue
+ if previous is not None:
+ total += 2 if previous.para_after else 1
+ total += len(text)
+ previous = unit
+ return total
+
+def _split_smart(text: str, max_words: int) -> List[str]:
+ """Smart strategy: fill chunks up to MAX_WORDS at sentence
+ boundaries, end them at the target once a quotation has closed or
+ a paragraph ends, and retreat cleanly instead of breaking quotes
+ when the next sentence does not fit. Every chunk also respects the
+ hard character cap, so punctuation-free or non-spaced input stays
+ bounded."""
+ target = max(1, round(max_words * _TARGET_RATIO))
+ floor = max(1, round(max_words * _FLOOR_RATIO))
+ char_cap = max_words * _MAX_CHARS_PER_WORD
+ chunks: List[str] = []
+ cur: List[_Unit] = []
+ cur_words = 0
+ cur_chars = 0
+
+ def flush() -> None:
+ nonlocal cur, cur_words, cur_chars
+ if cur:
+ chunks.append(_join(cur))
+ cur, cur_words, cur_chars = [], 0, 0
+
+ for unit in _scan_units(text):
+ if cur and cur_words >= target \
+ and (not cur[-1].in_quote_end or cur[-1].para_after):
+ flush()
+ if unit.words <= max_words \
+ and len(unit.text.strip()) <= char_cap \
+ and _joined_chars(cur + [unit]) <= char_cap:
+ if cur_words + unit.words <= max_words:
+ cur.append(unit)
+ cur_words += unit.words
+ cur_chars = _joined_chars(cur)
+ continue
+ # The sentence does not fit: break earlier if a clean
+ # boundary keeps the chunk above the floor.
+ point = _retreat_point(cur, floor)
+ if point < len(cur):
+ chunks.append(_join(cur[:point]))
+ cur = cur[point:]
+ cur_words = sum(u.words for u in cur)
+ cur_chars = _joined_chars(cur)
+ if cur_words + unit.words <= max_words:
+ cur.append(unit)
+ cur_words += unit.words
+ cur_chars = _joined_chars(cur)
+ continue
+ flush()
+ cur.append(unit)
+ cur_words = unit.words
+ cur_chars = _joined_chars(cur)
+ continue
+ # One piece exceeds the limit itself: send its pieces out
+ # packed as tightly as the pieces allow.
+ flush()
+ for piece_text in _split_oversized(unit.text, max_words):
+ if _count_words(piece_text) > max_words \
+ or len(piece_text) > char_cap:
+ # A character-sliced piece of degenerate input: its own
+ # chunk (already at the hard cap).
+ flush()
+ chunks.append(piece_text)
+ continue
+ piece = _Unit(piece_text, _count_words(piece_text), False, False)
+ if cur and cur_words + piece.words <= max_words \
+ and cur_chars + 1 + len(piece_text) <= char_cap:
+ cur.append(piece)
+ cur_words += piece.words
+ cur_chars += 1 + len(piece_text)
+ continue
+ flush()
+ cur.append(piece)
+ cur_words = piece.words
+ cur_chars = len(piece_text)
+ flush()
+ return [chunk for chunk in chunks if chunk.strip()]
+
+
+def _split_legacy(text: str, max_words: int) -> List[str]:
+ """The pre-smart splitter, kept intact for the Smart chunking=off
+ setting. Chunks pack whole sentences up to MAX_WORDS; sentences
+ longer than the limit split at clause punctuation, then at word
+ boundaries."""
sentences = re.split(r"(?<=[.!?])\s+", text)
chunks = []
current_chunk = ""
@@ -89,3 +403,49 @@ def split_into_chunks(text: str, max_words: Optional[int] = None) -> List[str]:
chunks.append(current_chunk.strip())
return [chunk for chunk in chunks if chunk.strip()]
+
+
+def split_into_chunks(text: str, max_words: Optional[int] = None,
+ smart: Optional[bool] = None) -> List[str]:
+ """Split text into chunks of at most ``max_words`` words.
+
+ ``max_words`` defaults to ``config.CHUNK_SIZE`` (read at call time).
+ There is no ceiling beyond that setting, but note that the TTS
+ servers silently truncate audio when a single generation runs too
+ long without reporting an error, so very large values are at your
+ own risk (see CHUNK_SIZE in app/converter/config.py).
+
+ With smart chunking on (``config.SMART_CHUNKING``, the default), a
+ chunk crossing the target (~85% of the limit) ends at the next
+ sentence end outside a quotation or at a paragraph break, so most
+ requests stop at natural boundaries instead of pressing against the
+ limit. When the next sentence will not fit, the break retreats to
+ the last boundary that ends outside a quotation (never smaller than
+ ~70% of the limit), so short quotations stay in one request when
+ possible; very long or unclosed quotes still split, carrying their
+ open state into the next chunk. Malformed punctuation never grows a
+ chunk beyond the limit: every break consumes text, and input without
+ sentence punctuation or whitespace (some CJK text, extraction
+ damage) falls back to clause punctuation, then word boundaries,
+ then a hard character cap. Content is preserved: no closing quote
+ or punctuation is ever invented or dropped.
+
+ Both strategies split on sentence boundaries. Sentences longer than
+ the limit are split further at clause punctuation (which is kept
+ attached for TTS prosody). Clause splits only happen at whitespace
+ after punctuation, so tokens like "1,000,000" or "12:30" are never
+ broken apart.
+ """
+ if max_words is None:
+ max_words = config.CHUNK_SIZE
+ if max_words < 1:
+ max_words = 1
+
+ if not text.strip():
+ return []
+
+ if smart is None:
+ smart = bool(getattr(config, "SMART_CHUNKING", False))
+ if smart:
+ return _split_smart(text, max_words)
+ return _split_legacy(text, max_words)
diff --git a/app/converter/config.py b/app/converter/config.py
index da73427..c021375 100644
--- a/app/converter/config.py
+++ b/app/converter/config.py
@@ -10,6 +10,13 @@ HEARTBEAT_INTERVAL_SECONDS = 30 # Print "still working" in console logs every N
# Words per TTS generation request (client-side chunking).
CHUNK_SIZE = 250
+# Chunking strategy. Smart chunking ends each request at the end of a
+# sentence or quotation instead of a mid-sentence overflow: chunks stay
+# at or below CHUNK_SIZE (most land slightly under it, aiming for a
+# natural boundary near 85%) and short quotations are kept in one
+# request when they fit. Turn it off for the exact legacy splitting.
+SMART_CHUNKING = True
+
# Where books are read from and where finished audiobooks are written.
# Relative paths resolve against the project root.
INPUT_DIR = "input"
diff --git a/app/converter/converter.py b/app/converter/converter.py
index 2b849a2..f8815d8 100644
--- a/app/converter/converter.py
+++ b/app/converter/converter.py
@@ -251,11 +251,11 @@ def chunk_clamp_needed(entry) -> bool:
def chunk_clamp_message(entry) -> List[str]:
"""The popup text for a chunk_words-capped ENTRY (short lines)."""
return [
- f"{entry.label} can narrate at most ~{entry.chunk_words} words "
- "per request: the server caps",
- "each request's prompt plus generation at a fixed window. "
- "Longer sub-chunks",
- "may cut off mid-sentence.",
+ f"{entry.label} narrates best at ~{entry.chunk_words} words "
+ "per request on this server:",
+ "each request's prompt plus generation must fit a fixed "
+ "window, so longer",
+ "sub-chunks may cut off mid-sentence.",
]
@@ -305,6 +305,9 @@ class AudiobookConverter:
# Class-level default so a partially-constructed instance (tests build
# these with __new__) behaves like a plain console run.
_progress = None
+ # Same for the per-run chunk override: without __init__ there is no
+ # clamp, so chunking follows the config.CHUNK_SIZE setting.
+ chunk_size = None
def __init__(self, voice_mode: str = VOICE_MODE_CUSTOM, voice_clone_ref_audio: Optional[str] = None,
voice_clone_ref_text: Optional[str] = None, skip_transcription: bool = False,
@@ -340,6 +343,12 @@ class AudiobookConverter:
self.backend = backend
self.voice = voice
self.debug = bool(debug)
+ # Per-run chunk-word override (the pre-flight popup's clamp for
+ # models whose engine caps one request below a full sub-chunk,
+ # SGLang-Omni's Higgs): caps the chapter chunks themselves so
+ # progress and debug dumps span one generation request each.
+ # None follows the config.CHUNK_SIZE setting.
+ self.chunk_size = chunk_size
# The run's model selection (audio.cpp: a server entry id, sglomni:
# the resolved catalog key, None elsewhere) — the startup banner
# reports it.
@@ -404,10 +413,9 @@ class AudiobookConverter:
"catalog key for --model (see the backend docs).")
model_id = entry.key
self.model_id = model_id
- # CHUNK_SIZE carries a per-run override (the pre-flight chunk
- # popup's clamp for models whose engine caps one request below
- # a full sub-chunk); None follows the config.CHUNK_SIZE setting.
- self.chunk_size = chunk_size
+ # The catalog/request shape is resolved below; the per-run
+ # chunk override (self.chunk_size) was recorded above and
+ # reaches the client here.
self.tts = SgOmniTTSClient(
chunks_dir=CHUNKS_FOLDER, model=model_id, voice=voice,
ref_audio=voice_clone_ref_audio,
@@ -839,8 +847,14 @@ class AudiobookConverter:
return results
def _chapter_chunks(self, text: str) -> List[str]:
- """Split chapter text into CHUNK_SIZE-word TTS requests."""
- return chunking.split_into_chunks(text)
+ """Split chapter text into word-capped TTS request chunks.
+
+ Each chunk is one progress unit; when the pre-flight popup set
+ a per-run clamp (models whose engine caps one request below
+ CHUNK_SIZE), it caps these chunks too so a chunk is never
+ wider than one generation request.
+ """
+ return chunking.split_into_chunks(text, max_words=self.chunk_size)
def _convert_text(self, text: str, output_path: Path, start_time: float,
speed: Optional[float] = None,