FunASR/funasr/models/frontend/wav_frontend.py
2023-02-13 17:43:01 +08:00

207 lines
7.1 KiB
Python

# Copyright (c) Alibaba, Inc. and its affiliates.
# Part of the implementation is borrowed from espnet/espnet.
from typing import Tuple
import numpy as np
import torch
import torchaudio.compliance.kaldi as kaldi
from funasr.models.frontend.abs_frontend import AbsFrontend
from typeguard import check_argument_types
from torch.nn.utils.rnn import pad_sequence
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)
class WavFrontend(AbsFrontend):
"""Conventional frontend structure for ASR.
"""
def __init__(
self,
cmvn_file: str = None,
fs: int = 16000,
window: str = 'hamming',
n_mels: int = 80,
frame_length: int = 25,
frame_shift: int = 10,
filter_length_min: int = -1,
filter_length_max: int = -1,
lfr_m: int = 1,
lfr_n: int = 1,
dither: float = 1.0,
snip_edges: bool = True,
upsacle_samples: bool = True,
):
assert check_argument_types()
super().__init__()
self.fs = fs
self.window = window
self.n_mels = n_mels
self.frame_length = frame_length
self.frame_shift = frame_shift
self.filter_length_min = filter_length_min
self.filter_length_max = filter_length_max
self.lfr_m = lfr_m
self.lfr_n = lfr_n
self.cmvn_file = cmvn_file
self.dither = dither
self.snip_edges = snip_edges
self.upsacle_samples = upsacle_samples
def output_size(self) -> int:
return self.n_mels * self.lfr_m
def forward(
self,
input: torch.Tensor,
input_lengths: torch.Tensor) -> Tuple[torch.Tensor, torch.Tensor]:
batch_size = input.size(0)
feats = []
feats_lens = []
for i in range(batch_size):
waveform_length = input_lengths[i]
waveform = input[i][:waveform_length]
if self.upsacle_samples:
waveform = waveform * (1 << 15)
waveform = waveform.unsqueeze(0)
mat = kaldi.fbank(waveform,
num_mel_bins=self.n_mels,
frame_length=self.frame_length,
frame_shift=self.frame_shift,
dither=self.dither,
energy_floor=0.0,
window_type=self.window,
sample_frequency=self.fs,
snip_edges=self.snip_edges)
if self.lfr_m != 1 or self.lfr_n != 1:
mat = apply_lfr(mat, self.lfr_m, self.lfr_n)
if self.cmvn_file is not None:
mat = apply_cmvn(mat, self.cmvn_file)
feat_length = mat.size(0)
feats.append(mat)
feats_lens.append(feat_length)
feats_lens = torch.as_tensor(feats_lens)
feats_pad = pad_sequence(feats,
batch_first=True,
padding_value=0.0)
return feats_pad, feats_lens
def forward_fbank(
self,
input: torch.Tensor,
input_lengths: torch.Tensor) -> Tuple[torch.Tensor, torch.Tensor]:
batch_size = input.size(0)
feats = []
feats_lens = []
for i in range(batch_size):
waveform_length = input_lengths[i]
waveform = input[i][:waveform_length]
waveform = waveform * (1 << 15)
waveform = waveform.unsqueeze(0)
mat = kaldi.fbank(waveform,
num_mel_bins=self.n_mels,
frame_length=self.frame_length,
frame_shift=self.frame_shift,
dither=self.dither,
energy_floor=0.0,
window_type=self.window,
sample_frequency=self.fs)
feat_length = mat.size(0)
feats.append(mat)
feats_lens.append(feat_length)
feats_lens = torch.as_tensor(feats_lens)
feats_pad = pad_sequence(feats,
batch_first=True,
padding_value=0.0)
return feats_pad, feats_lens
def forward_lfr_cmvn(
self,
input: torch.Tensor,
input_lengths: torch.Tensor) -> Tuple[torch.Tensor, torch.Tensor]:
batch_size = input.size(0)
feats = []
feats_lens = []
for i in range(batch_size):
mat = input[i, :input_lengths[i], :]
if self.lfr_m != 1 or self.lfr_n != 1:
mat = apply_lfr(mat, self.lfr_m, self.lfr_n)
if self.cmvn_file is not None:
mat = apply_cmvn(mat, self.cmvn_file)
feat_length = mat.size(0)
feats.append(mat)
feats_lens.append(feat_length)
feats_lens = torch.as_tensor(feats_lens)
feats_pad = pad_sequence(feats,
batch_first=True,
padding_value=0.0)
return feats_pad, feats_lens