icefall/egs/wenetspeech/ASR/local/prepare_pinyin.py
2024-03-04 23:28:04 +08:00

277 lines
7.7 KiB
Python
Executable File

#!/usr/bin/env python
# -*- coding: utf-8 -*-
# Copyright 2023 Xiaomi Corp. (authors: Wei Kang)
#
# See ../../../../LICENSE for clarification regarding multiple authors
#
# 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.
"""
This script takes as input `lang_dir`, which should contain::
- lang_dir/words.txt
and generates the following files in the directory `lang_dir`:
- lexicon.txt
- lexicon_disambig.txt
- L.pt
- L_disambig.pt
- tokens.txt
"""
import argparse
import re
from pathlib import Path
from typing import Dict, List
import k2
import torch
from prepare_lang import (
Lexicon,
add_disambig_symbols,
add_self_loops,
write_lexicon,
write_mapping,
)
from icefall.utils import text_to_pinyin
def get_parser():
parser = argparse.ArgumentParser(
description="Prepare lang for pinyin",
formatter_class=argparse.ArgumentDefaultsHelpFormatter,
)
parser.add_argument("--lang-dir", type=str, help="The lang directory.")
parser.add_argument(
"--token-type",
default="full_with_tone",
type=str,
help="""The type of pinyin, should be in:
full_with_tone: zhōng guó
full_no_tone: zhong guo
partial_with_tone: zh ōng g uó
partial_no_tone: zh ong g uo
""",
)
parser.add_argument(
"--pinyin-errors",
default="split",
type=str,
help="""How to handle characters that has no pinyin,
see `text_to_pinyin` in icefall/utils.py for details
""",
)
return parser
def lexicon_to_fst_no_sil(
lexicon: Lexicon,
token2id: Dict[str, int],
word2id: Dict[str, int],
need_self_loops: bool = False,
) -> k2.Fsa:
"""Convert a lexicon to an FST (in k2 format).
Args:
lexicon:
The input lexicon. See also :func:`read_lexicon`
token2id:
A dict mapping tokens to IDs.
word2id:
A dict mapping words to IDs.
need_self_loops:
If True, add self-loop to states with non-epsilon output symbols
on at least one arc out of the state. The input label for this
self loop is `token2id["#0"]` and the output label is `word2id["#0"]`.
Returns:
Return an instance of `k2.Fsa` representing the given lexicon.
"""
loop_state = 0 # words enter and leave from here
next_state = 1 # the next un-allocated state, will be incremented as we go
arcs = []
# The blank symbol <blk> is defined in local/train_bpe_model.py
assert token2id["<blk>"] == 0
assert word2id["<eps>"] == 0
eps = 0
for word, pieces in lexicon:
assert len(pieces) > 0, f"{word} has no pronunciations"
cur_state = loop_state
word = word2id[word]
pieces = [token2id[i] if i in token2id else token2id["<unk>"] for i in pieces]
for i in range(len(pieces) - 1):
w = word if i == 0 else eps
arcs.append([cur_state, next_state, pieces[i], w, 0])
cur_state = next_state
next_state += 1
# now for the last piece of this word
i = len(pieces) - 1
w = word if i == 0 else eps
arcs.append([cur_state, loop_state, pieces[i], w, 0])
if need_self_loops:
disambig_token = token2id["#0"]
disambig_word = word2id["#0"]
arcs = add_self_loops(
arcs,
disambig_token=disambig_token,
disambig_word=disambig_word,
)
final_state = next_state
arcs.append([loop_state, final_state, -1, -1, 0])
arcs.append([final_state])
arcs = sorted(arcs, key=lambda arc: arc[0])
arcs = [[str(i) for i in arc] for arc in arcs]
arcs = [" ".join(arc) for arc in arcs]
arcs = "\n".join(arcs)
fsa = k2.Fsa.from_str(arcs, acceptor=False)
return fsa
def contain_oov(token_sym_table: Dict[str, int], tokens: List[str]) -> bool:
"""Check if all the given tokens are in token symbol table.
Args:
token_sym_table:
Token symbol table that contains all the valid tokens.
tokens:
A list of tokens.
Returns:
Return True if there is any token not in the token_sym_table,
otherwise False.
"""
for tok in tokens:
if tok not in token_sym_table:
return True
return False
def generate_lexicon(
args, token_sym_table: Dict[str, int], words: List[str]
) -> Lexicon:
"""Generate a lexicon from a word list and token_sym_table.
Args:
token_sym_table:
Token symbol table that mapping token to token ids.
words:
A list of strings representing words.
Returns:
Return a dict whose keys are words and values are the corresponding
tokens.
"""
lexicon = []
for word in words:
tokens = text_to_pinyin(
word.strip(), mode=args.token_type, errors=args.pinyin_errors
)
if contain_oov(token_sym_table, tokens):
print(f"Word : {word} contains OOV token, skipping.")
continue
lexicon.append((word, tokens))
# The OOV word is <UNK>
lexicon.append(("<UNK>", ["<unk>"]))
return lexicon
def generate_tokens(args, words: List[str]) -> Dict[str, int]:
"""Generate tokens from the given word list.
Args:
words:
A list that contains words to generate tokens.
Returns:
Return a dict whose keys are tokens and values are token ids ranged
from 0 to len(keys) - 1.
"""
tokens: Dict[str, int] = dict()
tokens["<blk>"] = 0
tokens["<sos/eos>"] = 1
tokens["<unk>"] = 2
for word in words:
word = word.strip()
tokens_list = text_to_pinyin(
word, mode=args.token_type, errors=args.pinyin_errors
)
for token in tokens_list:
if token not in tokens:
tokens[token] = len(tokens)
return tokens
def main():
parser = get_parser()
args = parser.parse_args()
lang_dir = Path(args.lang_dir)
word_sym_table = k2.SymbolTable.from_file(lang_dir / "words.txt")
words = word_sym_table.symbols
excluded = ["<eps>", "!SIL", "<SPOKEN_NOISE>", "<UNK>", "#0", "<s>", "</s>"]
for w in excluded:
if w in words:
words.remove(w)
token_sym_table = generate_tokens(args, words)
lexicon = generate_lexicon(args, token_sym_table, words)
lexicon_disambig, max_disambig = add_disambig_symbols(lexicon)
next_token_id = max(token_sym_table.values()) + 1
for i in range(max_disambig + 1):
disambig = f"#{i}"
assert disambig not in token_sym_table
token_sym_table[disambig] = next_token_id
next_token_id += 1
word_sym_table.add("#0")
word_sym_table.add("<s>")
word_sym_table.add("</s>")
write_mapping(lang_dir / "tokens.txt", token_sym_table)
write_lexicon(lang_dir / "lexicon.txt", lexicon)
write_lexicon(lang_dir / "lexicon_disambig.txt", lexicon_disambig)
L = lexicon_to_fst_no_sil(
lexicon,
token2id=token_sym_table,
word2id=word_sym_table,
)
L_disambig = lexicon_to_fst_no_sil(
lexicon_disambig,
token2id=token_sym_table,
word2id=word_sym_table,
need_self_loops=True,
)
torch.save(L.as_dict(), lang_dir / "L.pt")
torch.save(L_disambig.as_dict(), lang_dir / "L_disambig.pt")
if __name__ == "__main__":
main()