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PaddleSpeech/paddlespeech/s2t/transform/cmvn.py

198 lines
6.4 KiB

# Copyright (c) 2021 PaddlePaddle Authors. All Rights Reserved.
#
# 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.
# Modified from espnet(https://github.com/espnet/espnet)
import io
import json
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import h5py
import kaldiio
import numpy as np
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class CMVN():
"Apply Global/Spk CMVN/iverserCMVN."
def __init__(
self,
stats,
norm_means=True,
norm_vars=False,
filetype="mat",
utt2spk=None,
spk2utt=None,
reverse=False,
std_floor=1.0e-20, ):
self.stats_file = stats
self.norm_means = norm_means
self.norm_vars = norm_vars
self.reverse = reverse
if isinstance(stats, dict):
stats_dict = dict(stats)
else:
# Use for global CMVN
if filetype == "mat":
stats_dict = {None: kaldiio.load_mat(stats)}
# Use for global CMVN
elif filetype == "npy":
stats_dict = {None: np.load(stats)}
# Use for speaker CMVN
elif filetype == "ark":
self.accept_uttid = True
stats_dict = dict(kaldiio.load_ark(stats))
# Use for speaker CMVN
elif filetype == "hdf5":
self.accept_uttid = True
stats_dict = h5py.File(stats)
else:
raise ValueError("Not supporting filetype={}".format(filetype))
if utt2spk is not None:
self.utt2spk = {}
with io.open(utt2spk, "r", encoding="utf-8") as f:
for line in f:
utt, spk = line.rstrip().split(None, 1)
self.utt2spk[utt] = spk
elif spk2utt is not None:
self.utt2spk = {}
with io.open(spk2utt, "r", encoding="utf-8") as f:
for line in f:
spk, utts = line.rstrip().split(None, 1)
for utt in utts.split():
self.utt2spk[utt] = spk
else:
self.utt2spk = None
# Kaldi makes a matrix for CMVN which has a shape of (2, feat_dim + 1),
# and the first vector contains the sum of feats and the second is
# the sum of squares. The last value of the first, i.e. stats[0,-1],
# is the number of samples for this statistics.
self.bias = {}
self.scale = {}
for spk, stats in stats_dict.items():
assert len(stats) == 2, stats.shape
count = stats[0, -1]
# If the feature has two or more dimensions
if not (np.isscalar(count) or isinstance(count, (int, float))):
# The first is only used
count = count.flatten()[0]
mean = stats[0, :-1] / count
# V(x) = E(x^2) - (E(x))^2
var = stats[1, :-1] / count - mean * mean
std = np.maximum(np.sqrt(var), std_floor)
self.bias[spk] = -mean
self.scale[spk] = 1 / std
def __repr__(self):
return ("{name}(stats_file={stats_file}, "
"norm_means={norm_means}, norm_vars={norm_vars}, "
"reverse={reverse})".format(
name=self.__class__.__name__,
stats_file=self.stats_file,
norm_means=self.norm_means,
norm_vars=self.norm_vars,
reverse=self.reverse, ))
def __call__(self, x, uttid=None):
if self.utt2spk is not None:
spk = self.utt2spk[uttid]
else:
spk = uttid
if not self.reverse:
# apply cmvn
if self.norm_means:
x = np.add(x, self.bias[spk])
if self.norm_vars:
x = np.multiply(x, self.scale[spk])
else:
# apply reverse cmvn
if self.norm_vars:
x = np.divide(x, self.scale[spk])
if self.norm_means:
x = np.subtract(x, self.bias[spk])
return x
class UtteranceCMVN():
"Apply Utterance CMVN"
def __init__(self, norm_means=True, norm_vars=False, std_floor=1.0e-20):
self.norm_means = norm_means
self.norm_vars = norm_vars
self.std_floor = std_floor
def __repr__(self):
return "{name}(norm_means={norm_means}, norm_vars={norm_vars})".format(
name=self.__class__.__name__,
norm_means=self.norm_means,
norm_vars=self.norm_vars, )
def __call__(self, x, uttid=None):
# x: [Time, Dim]
square_sums = (x**2).sum(axis=0)
mean = x.mean(axis=0)
if self.norm_means:
x = np.subtract(x, mean)
if self.norm_vars:
var = square_sums / x.shape[0] - mean**2
std = np.maximum(np.sqrt(var), self.std_floor)
x = np.divide(x, std)
return x
class GlobalCMVN():
"Apply Global CMVN"
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def __init__(self,
cmvn_path,
norm_means=True,
norm_vars=True,
std_floor=1.0e-20):
self.cmvn_path = cmvn_path
self.norm_means = norm_means
self.norm_vars = norm_vars
self.std_floor = std_floor
with open(cmvn_path) as f:
cmvn_stats = json.load(f)
self.count = cmvn_stats['frame_num']
self.mean = np.array(cmvn_stats['mean_stat']) / self.count
self.square_sums = np.array(cmvn_stats['var_stat'])
self.var = self.square_sums / self.count - self.mean**2
self.std = np.maximum(np.sqrt(self.var), self.std_floor)
def __repr__(self):
return f"""{self.__class__.__name__}(
cmvn_path={self.cmvn_path},
norm_means={self.norm_means},
norm_vars={self.norm_vars},)"""
def __call__(self, x, uttid=None):
# x: [Time, Dim]
if self.norm_means:
x = np.subtract(x, self.mean)
if self.norm_vars:
x = np.divide(x, self.std)
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return x