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PaddleSpeech/deepspeech/transform/channel_selector.py

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1.9 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.
import numpy
class ChannelSelector():
"""Select 1ch from multi-channel signal"""
def __init__(self, train_channel="random", eval_channel=0, axis=1):
self.train_channel = train_channel
self.eval_channel = eval_channel
self.axis = axis
def __repr__(self):
return ("{name}(train_channel={train_channel}, "
"eval_channel={eval_channel}, axis={axis})".format(
name=self.__class__.__name__,
train_channel=self.train_channel,
eval_channel=self.eval_channel,
axis=self.axis, ))
def __call__(self, x, train=True):
# Assuming x: [Time, Channel] by default
if x.ndim <= self.axis:
# If the dimension is insufficient, then unsqueeze
# (e.g [Time] -> [Time, 1])
ind = tuple(
slice(None) if i < x.ndim else None
for i in range(self.axis + 1))
x = x[ind]
if train:
channel = self.train_channel
else:
channel = self.eval_channel
if channel == "random":
ch = numpy.random.randint(0, x.shape[self.axis])
else:
ch = channel
ind = tuple(
slice(None) if i != self.axis else ch for i in range(x.ndim))
return x[ind]