FunASR/funasr/models/frontend/wav_frontend_kaldifeat.py
2023-04-27 17:51:13 +08:00

70 lines
2.3 KiB
Python

# Copyright (c) Alibaba, Inc. and its affiliates.
# Part of the implementation is borrowed from espnet/espnet.
import numpy as np
import torch
def load_cmvn(cmvn_file):
with open(cmvn_file, 'r', encoding='utf-8') as f:
lines = f.readlines()
means_list = []
vars_list = []
for i in range(len(lines)):
line_item = lines[i].split()
if line_item[0] == '<AddShift>':
line_item = lines[i + 1].split()
if line_item[0] == '<LearnRateCoef>':
add_shift_line = line_item[3:(len(line_item) - 1)]
means_list = list(add_shift_line)
continue
elif line_item[0] == '<Rescale>':
line_item = lines[i + 1].split()
if line_item[0] == '<LearnRateCoef>':
rescale_line = line_item[3:(len(line_item) - 1)]
vars_list = list(rescale_line)
continue
means = np.array(means_list).astype(np.float)
vars = np.array(vars_list).astype(np.float)
cmvn = np.array([means, vars])
cmvn = torch.as_tensor(cmvn)
return cmvn
def apply_cmvn(inputs, cmvn_file): # noqa
"""
Apply CMVN with mvn data
"""
device = inputs.device
dtype = inputs.dtype
frame, dim = inputs.shape
cmvn = load_cmvn(cmvn_file)
means = np.tile(cmvn[0:1, :dim], (frame, 1))
vars = np.tile(cmvn[1:2, :dim], (frame, 1))
inputs += torch.from_numpy(means).type(dtype).to(device)
inputs *= torch.from_numpy(vars).type(dtype).to(device)
return inputs.type(torch.float32)
def apply_lfr(inputs, lfr_m, lfr_n):
LFR_inputs = []
T = inputs.shape[0]
T_lfr = int(np.ceil(T / lfr_n))
left_padding = inputs[0].repeat((lfr_m - 1) // 2, 1)
inputs = torch.vstack((left_padding, inputs))
T = T + (lfr_m - 1) // 2
for i in range(T_lfr):
if lfr_m <= T - i * lfr_n:
LFR_inputs.append((inputs[i * lfr_n:i * lfr_n + lfr_m]).view(1, -1))
else: # process last LFR frame
num_padding = lfr_m - (T - i * lfr_n)
frame = (inputs[i * lfr_n:]).view(-1)
for _ in range(num_padding):
frame = torch.hstack((frame, inputs[-1]))
LFR_inputs.append(frame)
LFR_outputs = torch.vstack(LFR_inputs)
return LFR_outputs.type(torch.float32)