mirror of
https://github.com/k2-fsa/icefall.git
synced 2025-08-11 11:02:29 +00:00
54 lines
2.0 KiB
Python
54 lines
2.0 KiB
Python
#!/usr/bin/env python3
|
|
# Copyright 2023 Xiaomi Corp. (Author: Weiji Zhuang,
|
|
# Liyong Guo)
|
|
#
|
|
# 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.
|
|
|
|
from typing import List
|
|
|
|
|
|
def ctc_trivial_decoding_graph(wakeup_word_tokens: List[int]) -> str:
|
|
"""
|
|
A graph starts with blank/unknown and following by wakeup word.
|
|
|
|
Args:
|
|
wakeup_word_tokens: A sequence of token ids corresponding wakeup_word.
|
|
It should not contain 0 and 1.
|
|
We assume 0 is for blank and 1 is for unknown.
|
|
Returns:
|
|
Returns a finite-state transducer in string format,
|
|
used as a decoding graph.
|
|
Arcs are separated with "\n".
|
|
"""
|
|
assert 0 not in wakeup_word_tokens
|
|
assert 1 not in wakeup_word_tokens
|
|
assert len(wakeup_word_tokens) >= 2
|
|
keyword_ilabel_start = wakeup_word_tokens[0]
|
|
fst_graph = ""
|
|
for non_wake_word_token in range(keyword_ilabel_start):
|
|
fst_graph += f"0 0 {non_wake_word_token} 0\n"
|
|
cur_state = 1
|
|
for token_idx in range(len(wakeup_word_tokens) - 1):
|
|
token = wakeup_word_tokens[token_idx]
|
|
fst_graph += f"{cur_state - 1} {cur_state} {token} 0\n"
|
|
fst_graph += f"{cur_state} {cur_state} {token} 0\n"
|
|
cur_state += 1
|
|
|
|
token = wakeup_word_tokens[-1]
|
|
fst_graph += f"{cur_state - 1} {cur_state} {token} 1\n"
|
|
fst_graph += f"{cur_state} {cur_state} {token} 0\n"
|
|
fst_graph += f"{cur_state}\n"
|
|
return fst_graph
|