fbank online

This commit is contained in:
游雁 2023-02-22 20:10:20 +08:00
parent 33ca30ce6a
commit 2d7bd18d0e
2 changed files with 181 additions and 1 deletions

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@ -0,0 +1,180 @@
# 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
import kaldifeat
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_kaldifeat(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,
lfr_m: int = 1,
lfr_n: int = 1,
dither: float = 1.0,
snip_edges: bool = True,
upsacle_samples: bool = True,
device: str = 'cpu',
**kwargs,
):
super().__init__()
opts = kaldifeat.FbankOptions()
opts.device = device
opts.frame_opts.samp_freq = fs
opts.frame_opts.dither = dither
opts.frame_opts.window_type = window
opts.frame_opts.frame_shift_ms = float(frame_shift)
opts.frame_opts.frame_length_ms = float(frame_length)
opts.mel_opts.num_bins = n_mels
opts.energy_floor = 0
opts.frame_opts.snip_edges = snip_edges
opts.mel_opts.debug_mel = False
self.opts = opts
self.fbank_fn = None
self.fbank_beg_idx = 0
self.reset_fbank_status()
self.lfr_m = lfr_m
self.lfr_n = lfr_n
self.cmvn_file = cmvn_file
self.upsacle_samples = upsacle_samples
def output_size(self) -> int:
return self.n_mels * self.lfr_m
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)
self.fbank_fn.accept_waveform(self.opts.frame_opts.samp_freq, waveform.tolist())
frames = self.fbank_fn.num_frames_ready
frames_cur = frames - self.fbank_beg_idx
mat = torch.empty([frames_cur, self.opts.mel_opts.num_bins], dtype=torch.float32).to(
device=self.opts.device)
for i in range(self.fbank_beg_idx, frames):
mat[i, :] = self.fbank_fn.get_frame(i)
self.fbank_beg_idx += frames_cur
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 reset_fbank_status(self):
self.fbank_fn = kaldifeat.OnlineFbank(self.opts)
self.fbank_beg_idx = 0
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

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@ -76,7 +76,7 @@ class WavFrontend():
mat = np.empty([frames, self.opts.mel_opts.num_bins])
for i in range(self.fbank_beg_idx, frames):
mat[i, :] = self.fbank_fn.get_frame(i)
self.fbank_beg_idx += (frames-self.fbank_beg_idx)
# self.fbank_beg_idx += (frames-self.fbank_beg_idx)
feat = mat.astype(np.float32)
feat_len = np.array(mat.shape[0]).astype(np.int32)
return feat, feat_len