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#!/usr/bin/env python3
# -*- coding: utf-8 -*-
#
# Copyright 2016-2099 Ailemon.net
#
# This file is part of ASRT Speech Recognition Tool.
#
# ASRT is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
# ASRT is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with ASRT. If not, see <https://www.gnu.org/licenses/>.
# ============================================================================
"""
@author: nl8590687
一些常用操作函数的定义
"""
import wave
import difflib
import matplotlib.pyplot as plt
import numpy as np
def read_wav_data(filename: str) -> tuple:
"""
读取一个wav文件,返回声音信号的时域谱矩阵和播放时间
"""
wav = wave.open(filename,"rb") # 打开一个wav格式的声音文件流
num_frame = wav.getnframes() # 获取帧数
num_channel=wav.getnchannels() # 获取声道数
framerate=wav.getframerate() # 获取帧速率
num_sample_width=wav.getsampwidth() # 获取实例的比特宽度,即每一帧的字节数
str_data = wav.readframes(num_frame) # 读取全部的帧
wav.close() # 关闭流
wave_data = np.fromstring(str_data, dtype = np.short) # 将声音文件数据转换为数组矩阵形式
wave_data.shape = -1, num_channel # 按照声道数将数组整形,单声道时候是一列数组,双声道时候是两列的矩阵
wave_data = wave_data.T # 将矩阵转置
return wave_data, framerate, num_channel, num_sample_width
def read_wav_bytes(filename: str) -> tuple:
"""
读取一个wav文件,返回声音信号的时域谱矩阵和播放时间
"""
wav = wave.open(filename,"rb") # 打开一个wav格式的声音文件流
num_frame = wav.getnframes() # 获取帧数
num_channel=wav.getnchannels() # 获取声道数
framerate=wav.getframerate() # 获取帧速率
num_sample_width=wav.getsampwidth() # 获取实例的比特宽度,即每一帧的字节数
str_data = wav.readframes(num_frame) # 读取全部的帧
wav.close() # 关闭流
return str_data, framerate, num_channel, num_sample_width
def get_edit_distance(str1, str2) -> int:
"""
计算两个串的编辑距离,支持str和list类型
"""
leven_cost = 0
sequence_match = difflib.SequenceMatcher(None, str1, str2)
for tag, index_1, index_2, index_j1, index_j2 in sequence_match.get_opcodes():
if tag == 'replace':
leven_cost += max(index_2-index_1, index_j2-index_j1)
elif tag == 'insert':
leven_cost += (index_j2-index_j1)
elif tag == 'delete':
leven_cost += (index_2-index_1)
return leven_cost
def ctc_decode_delete_tail_blank(ctc_decode_list):
"""
处理CTC解码后序列末尾余留的空白元素,删除掉
"""
p = 0
while p < len(ctc_decode_list) and ctc_decode_list[p] != -1:
p += 1
return ctc_decode_list[0:p]
def visual_1D(points_list, frequency=1):
"""
可视化1D数据
"""
# 首先创建绘图网格,1个子图
fig, ax = plt.subplots(1)
x = np.linspace(0, len(points_list)-1, len(points_list)) / frequency
# 在对应对象上调用 plot() 方法
ax.plot(x, points_list)
fig.show()
def visual_2D(img):
"""
可视化2D数据
"""
plt.subplot(111)
plt.imshow(img)
plt.colorbar(cax=None, ax=None, shrink=0.5)
plt.show()
def decode_wav_bytes(samples_data: bytes, channels: int = 1, byte_width: int = 2) -> list:
"""
解码wav格式样本点字节流,得到numpy数组
"""
numpy_type = np.short
if byte_width == 4:
numpy_type = np.int
elif byte_width != 2:
raise Exception('error: unsurpport byte width `' + str(byte_width) + '`')
wave_data = np.fromstring(samples_data, dtype=numpy_type) # 将声音文件数据转换为数组矩阵形式
wave_data.shape = -1, channels # 按照声道数将数组整形,单声道时候是一列数组,双声道时候是两列的矩阵
wave_data = wave_data.T # 将矩阵转置
return wave_data
def get_symbol_dict(dict_filename):
"""
读取拼音汉字的字典文件
返回读取后的字典
"""
txt_obj = open(dict_filename, 'r', encoding='UTF-8') # 打开文件并读入
txt_text = txt_obj.read()
txt_obj.close()
txt_lines = txt_text.split('\n') # 文本分割
dic_symbol = {} # 初始化符号字典
for i in txt_lines:
list_symbol = [] # 初始化符号列表
if i != '':
txt_l=i.split('\t')
pinyin = txt_l[0]
for word in txt_l[1]:
list_symbol.append(word)
dic_symbol[pinyin] = list_symbol
return dic_symbol
def get_language_model(model_language_filename):
"""
读取语言模型的文件
返回读取后的模型
"""
txt_obj = open(model_language_filename, 'r', encoding='UTF-8') # 打开文件并读入
txt_text = txt_obj.read()
txt_obj.close()
txt_lines = txt_text.split('\n') # 文本分割
dic_model = {} # 初始化符号字典
for i in txt_lines:
if i != '':
txt_l = i.split('\t')
if len(txt_l) == 1:
continue
dic_model[txt_l[0]] = txt_l[1]
return dic_model
def ctc_decode_stream(tokens):
i = 0
while i < len(tokens):
while i+1 < len(tokens) and tokens[i] == tokens[i+1]:
i += 1
if i+1 == len(tokens) and tokens[i] != -1:
return tokens[0], []
if tokens[i] != -1:
return tokens[i], tokens[i+1:]
i += 1
return -1, []