def model(flags):
"""Fully connected layer based model.
It is based on paper (with added pooling):
SMALL-FOOTPRINT KEYWORD SPOTTING USING DEEP NEURAL NETWORKS
https://static.googleusercontent.com/media/research.google.com/en//pubs/archive/42537.pdf
Hello Edge: Keyword Spotting on Microcontrollers
https://arxiv.org/pdf/1711.07128.pdf
Args:
flags: data/model parameters
Returns:
Keras model for training
"""
input_audio = tf.keras.layers.Input(
shape=(flags.desired_samples,), batch_size=flags.batch_size)
net = speech_features.SpeechFeatures(
frame_size_ms=flags.window_size_ms,
frame_step_ms=flags.window_stride_ms,
sample_rate=flags.sample_rate,
use_tf_fft=flags.use_tf_fft,
preemph=flags.preemph,
window_type=flags.window_type,
mel_num_bins=flags.mel_num_bins,
mel_lower_edge_hertz=flags.mel_lower_edge_hertz,
mel_upper_edge_hertz=flags.mel_upper_edge_hertz,
mel_non_zero_only=flags.mel_non_zero_only,
fft_magnitude_squared=flags.fft_magnitude_squared,
dct_num_features=flags.dct_num_features)(
input_audio)
for units, activation in zip(parse(flags.units1), parse(flags.act1)):
net = tf.keras.layers.Dense(units=units, activation=activation)(net)
net = Stream(cell=tf.keras.layers.Flatten())(net)
# after flattening data in time, we can apply any layer: pooling, bi-lstm etc
if flags.pool_size > 1:
# add fake dim for compatibility with pooling
net = tf.keras.backend.expand_dims(net, axis=-1)
net = tf.keras.layers.MaxPool1D(
pool_size=flags.pool_size,
strides=flags.strides,
data_format='channels_last')(net)
# remove fake dim
net = tf.keras.backend.squeeze(net, axis=-1)
net = tf.keras.layers.Dropout(rate=flags.dropout1)(net)
for units, activation in zip(parse(flags.units2), parse(flags.act2)):
net = tf.keras.layers.Dense(units=units, activation=activation)(net)
net = tf.keras.layers.Dense(units=flags.label_count)(net)
return tf.keras.Model(input_audio, net)
def model(flags):
"""Convolutional recurrent neural network (CRNN) model.
It is based on paper
Convolutional Recurrent Neural Networks for Small-Footprint Keyword Spotting
https://arxiv.org/pdf/1703.05390.pdf
Represented as sequence of Conv, RNN/GRU, FC layers.
Model topology is similar with "Hello Edge: Keyword Spotting on
Microcontrollers" https://arxiv.org/pdf/1711.07128.pdf
Args:
flags: data/model parameters
Returns:
Keras model for training
"""
input_audio = tf.keras.layers.Input(shape=modes.get_input_data_shape(
flags, modes.Modes.TRAINING),
batch_size=flags.batch_size)
net = input_audio
if flags.preprocess == 'raw':
# it is a self contained model, user need to feed raw audio only
net = speech_features.SpeechFeatures(
speech_features.SpeechFeatures.get_params(flags))(net)
# expand dims for the next layer 2d conv
net = tf.keras.backend.expand_dims(net)
for filters, kernel_size, activation, dilation_rate, strides in zip(
parse(flags.cnn_filters), parse(flags.cnn_kernel_size),
parse(flags.cnn_act), parse(flags.cnn_dilation_rate),
parse(flags.cnn_strides)):
net = stream.Stream(
cell=tf.keras.layers.Conv2D(filters=filters,
kernel_size=kernel_size,
activation=activation,
dilation_rate=dilation_rate,
strides=strides))(net)
shape = net.shape
# input net dimension: [batch, time, feature, channels]
# reshape dimension: [batch, time, feature * channels]
# so that GRU/RNN can process it
net = tf.keras.layers.Reshape((-1, shape[2] * shape[3]))(net)
for units, return_sequences in zip(parse(flags.gru_units),
parse(flags.return_sequences)):
net = gru.GRU(units=units,
return_sequences=return_sequences,
stateful=flags.stateful)(net)
net = stream.Stream(cell=tf.keras.layers.Flatten())(net)
net = tf.keras.layers.Dropout(rate=flags.dropout1)(net)
for units, activation in zip(parse(flags.units1), parse(flags.act1)):
net = tf.keras.layers.Dense(units=units, activation=activation)(net)
net = tf.keras.layers.Dense(units=flags.label_count)(net)
if flags.return_softmax:
net = tf.keras.layers.Activation('softmax')(net)
return tf.keras.Model(input_audio, net)
def model(flags):
"""Fully connected layer based model.
It is based on paper (with added pooling):
SMALL-FOOTPRINT KEYWORD SPOTTING USING DEEP NEURAL NETWORKS
https://static.googleusercontent.com/media/research.google.com/en//pubs/archive/42537.pdf
Model topology is similar with "Hello Edge: Keyword Spotting on
Microcontrollers" https://arxiv.org/pdf/1711.07128.pdf
Args:
flags: data/model parameters
Returns:
Keras model for training
"""
input_audio = tf.keras.layers.Input(
shape=modes.get_input_data_shape(flags, modes.Modes.TRAINING),
batch_size=flags.batch_size)
net = input_audio
if flags.preprocess == 'raw':
# it is a self contained model, user need to feed raw audio only
net = speech_features.SpeechFeatures(
speech_features.SpeechFeatures.get_params(flags))(
net)
for units, activation in zip(
utils.parse(flags.units1), utils.parse(flags.act1)):
net = tf.keras.layers.Dense(units=units, activation=activation)(net)
net = stream.Stream(cell=tf.keras.layers.Flatten())(net)
# after flattening data in time, we can apply any layer: pooling, bi-lstm etc
if flags.pool_size > 1:
# add fake dim for compatibility with pooling
net = tf.keras.backend.expand_dims(net, axis=-1)
net = tf.keras.layers.MaxPool1D(
pool_size=flags.pool_size,
strides=flags.strides,
data_format='channels_last')(net)
# remove fake dim
net = tf.keras.backend.squeeze(net, axis=-1)
net = tf.keras.layers.Dropout(rate=flags.dropout1)(net)
for units, activation in zip(
utils.parse(flags.units2), utils.parse(flags.act2)):
net = tf.keras.layers.Dense(units=units, activation=activation)(net)
net = tf.keras.layers.Dense(units=flags.label_count)(net)
if flags.return_softmax:
net = tf.keras.layers.Activation('softmax')(net)
return tf.keras.Model(input_audio, net)
def model(flags):
"""Inception resnet model.
It is based on paper:
Inception-v4, Inception-ResNet and the Impact of
Residual Connections on Learning https://arxiv.org/abs/1602.07261
Args:
flags: data/model parameters
Returns:
Keras model for training
"""
input_audio = tf.keras.layers.Input(shape=modes.get_input_data_shape(
flags, modes.Modes.TRAINING),
batch_size=flags.batch_size)
net = input_audio
if flags.preprocess == 'raw':
# it is a self contained model, user need to feed raw audio only
net = speech_features.SpeechFeatures(
speech_features.SpeechFeatures.get_params(flags))(net)
# [batch, time, feature]
net = tf.keras.backend.expand_dims(net, axis=-1)
# [batch, time, feature, 1]
for filters in utils.parse(flags.cnn_filters0):
net = tf.keras.layers.SeparableConv2D(filters, (3, 3),
padding='valid',
use_bias=False)(net)
net = tf.keras.layers.BatchNormalization(scale=flags.bn_scale)(net)
net = tf.keras.layers.Activation('relu')(net)
net = tf.keras.layers.MaxPooling2D((3, 3), strides=(2, 2))(net)
# [batch, time, feature, filters]
for stride, scale, filters_branch0, filters_branch1 in zip(
utils.parse(flags.strides), utils.parse(flags.scales),
utils.parse(flags.filters_branch0),
utils.parse(flags.filters_branch1)):
net = inception_resnet_block(net,
scale,
filters_branch0,
filters_branch1,
bn_scale=flags.bn_scale)
net = tf.keras.layers.MaxPooling2D(3, strides=stride,
padding='valid')(net)
# [batch, time, feature, filters]
net = tf.keras.layers.GlobalAveragePooling2D()(net)
# [batch, filters]
net = tf.keras.layers.Dropout(flags.dropout)(net)
net = tf.keras.layers.Dense(flags.label_count)(net)
return tf.keras.Model(input_audio, net)
def model(flags):
"""LSTM model.
Similar model in papers:
Convolutional Recurrent Neural Networks for Small-Footprint Keyword Spotting
https://arxiv.org/pdf/1703.05390.pdf (with no conv layer)
Hello Edge: Keyword Spotting on Microcontrollers
https://arxiv.org/pdf/1711.07128.pdf
Args:
flags: data/model parameters
Returns:
Keras model for training
"""
input_audio = tf.keras.layers.Input(
shape=(flags.desired_samples,), batch_size=flags.batch_size)
net = speech_features.SpeechFeatures(
frame_size_ms=flags.window_size_ms,
frame_step_ms=flags.window_stride_ms,
sample_rate=flags.sample_rate,
use_tf_fft=flags.use_tf_fft,
preemph=flags.preemph,
window_type=flags.window_type,
mel_num_bins=flags.mel_num_bins,
mel_lower_edge_hertz=flags.mel_lower_edge_hertz,
mel_upper_edge_hertz=flags.mel_upper_edge_hertz,
mel_non_zero_only=flags.mel_non_zero_only,
fft_magnitude_squared=flags.fft_magnitude_squared,
dct_num_features=flags.dct_num_features)(
input_audio)
for units, return_sequences, num_proj in zip(
parse(flags.lstm_units), parse(flags.return_sequences),
parse(flags.num_proj)):
net = LSTM(
units=units,
return_sequences=return_sequences,
stateful=flags.stateful,
use_peepholes=flags.use_peepholes,
num_proj=num_proj)(
net)
net = Stream(cell=tf.keras.layers.Flatten())(net)
net = tf.keras.layers.Dropout(rate=flags.dropout1)(net)
for units, activation in zip(parse(flags.units1), parse(flags.act1)):
net = tf.keras.layers.Dense(units=units, activation=activation)(net)
net = tf.keras.layers.Dense(units=flags.label_count)(net)
return tf.keras.Model(input_audio, net)
def model(flags):
"""Fully connected layer based model on raw wav data.
It is based on paper (with added pooling and raw audio data):
SMALL-FOOTPRINT KEYWORD SPOTTING USING DEEP NEURAL NETWORKS
https://static.googleusercontent.com/media/research.google.com/en//pubs/archive/42537.pdf
Args:
flags: data/model parameters
Returns:
Keras model for training
"""
if flags.preprocess != 'raw':
ValueError('input audio has to be raw, but get ', flags.preprocess)
input_audio = tf.keras.layers.Input(
shape=(flags.desired_samples,), batch_size=flags.batch_size)
net = data_frame.DataFrame(
frame_size=flags.window_size_samples,
frame_step=flags.window_stride_samples)(
input_audio)
for units, activation in zip(
utils.parse(flags.units1), utils.parse(flags.act1)):
net = tf.keras.layers.Dense(units=units, activation=activation)(net)
net = stream.Stream(cell=tf.keras.layers.Flatten())(net)
# after flattening data in time, we can apply any layer: pooling, bi-lstm etc
if flags.pool_size > 1:
# add fake dim for compatibility with pooling
net = tf.keras.backend.expand_dims(net, axis=-1)
net = tf.keras.layers.MaxPool1D(
pool_size=flags.pool_size,
strides=flags.strides,
data_format='channels_last')(
net)
# remove fake dim
net = tf.keras.backend.squeeze(net, axis=-1)
net = tf.keras.layers.Dropout(rate=flags.dropout1)(net)
for units, activation in zip(
utils.parse(flags.units2), utils.parse(flags.act2)):
net = tf.keras.layers.Dense(units=units, activation=activation)(net)
net = tf.keras.layers.Dense(units=flags.label_count)(net)
if flags.return_softmax:
net = tf.keras.layers.Activation('softmax')(net)
return tf.keras.Model(input_audio, net)
def model(flags):
"""LSTM model.
Similar model in papers:
Convolutional Recurrent Neural Networks for Small-Footprint Keyword Spotting
https://arxiv.org/pdf/1703.05390.pdf (with no conv layer)
Model topology is similar with "Hello Edge: Keyword Spotting on
Microcontrollers" https://arxiv.org/pdf/1711.07128.pdf
Args:
flags: data/model parameters
Returns:
Keras model for training
"""
input_audio = tf.keras.layers.Input(
shape=modes.get_input_data_shape(flags, modes.Modes.TRAINING),
batch_size=flags.batch_size)
net = input_audio
if flags.preprocess == 'raw':
# it is a self contained model, user need to feed raw audio only
net = speech_features.SpeechFeatures(
speech_features.SpeechFeatures.get_params(flags))(
net)
for units, return_sequences, num_proj in zip(
parse(flags.lstm_units), parse(flags.return_sequences),
parse(flags.num_proj)):
net = LSTM(
units=units,
return_sequences=return_sequences,
stateful=flags.stateful,
use_peepholes=flags.use_peepholes,
num_proj=num_proj)(
net)
net = Stream(cell=tf.keras.layers.Flatten())(net)
net = tf.keras.layers.Dropout(rate=flags.dropout1)(net)
for units, activation in zip(parse(flags.units1), parse(flags.act1)):
net = tf.keras.layers.Dense(units=units, activation=activation)(net)
net = tf.keras.layers.Dense(units=flags.label_count)(net)
if flags.return_softmax:
net = tf.keras.layers.Activation('softmax')(net)
return tf.keras.Model(input_audio, net)
def model(flags):
"""LSTM model.
It is based on paper https://arxiv.org/pdf/1705.02411.pdf
Args:
flags: data/model parameters
Returns:
Keras model for training
"""
input_audio = tf.keras.layers.Input(shape=(flags.desired_samples, ),
batch_size=flags.batch_size)
net = speech_features.SpeechFeatures(
frame_size_ms=flags.window_size_ms,
frame_step_ms=flags.window_stride_ms,
sample_rate=flags.sample_rate,
use_tf_fft=flags.use_tf_fft,
preemph=flags.preemph,
window_type=flags.window_type,
mel_num_bins=flags.mel_num_bins,
mel_lower_edge_hertz=flags.mel_lower_edge_hertz,
mel_upper_edge_hertz=flags.mel_upper_edge_hertz,
mel_non_zero_only=flags.mel_non_zero_only,
fft_magnitude_squared=flags.fft_magnitude_squared,
dct_num_features=flags.dct_num_features)(input_audio)
for units, return_sequences, num_proj in zip(parse(flags.lstm_units),
parse(flags.return_sequences),
parse(flags.num_proj)):
net = LSTM(units=units,
return_sequences=return_sequences,
stateful=flags.stateful,
use_peepholes=flags.use_peepholes,
num_proj=num_proj)(net)
net = Stream(cell=tf.keras.layers.Flatten())(net)
net = tf.keras.layers.Dropout(rate=flags.dropout1)(net)
for units, activation in zip(parse(flags.units1), parse(flags.act1)):
net = tf.keras.layers.Dense(units=units, activation=activation)(net)
net = tf.keras.layers.Dense(units=flags.label_count)(net)
return tf.keras.Model(input_audio, net)
def model(flags):
"""Fully connected layer based model on raw wav data.
It is absed on paper (with added pooling and raw audio data):
https://static.googleusercontent.com/media/research.google.com/en//pubs/archive/42537.pdf
Args:
flags: data/model parameters
Returns:
Keras model for training
"""
input_audio = tf.keras.layers.Input(shape=(flags.desired_samples, ),
batch_size=flags.batch_size)
net = dataframe.DataFrame(
frame_size=flags.window_size_samples,
frame_step=flags.window_stride_samples)(input_audio)
for units, activation in zip(parse(flags.units1), parse(flags.act1)):
net = tf.keras.layers.Dense(units=units, activation=activation)(net)
net = Stream(cell=tf.keras.layers.Flatten())(net)
# after flattening data in time, we can apply any layer: pooling, bi-lstm etc
if flags.pool_size > 1:
# add fake dim for compatibility with pooling
net = tf.keras.backend.expand_dims(net, axis=-1)
net = tf.keras.layers.MaxPool1D(pool_size=flags.pool_size,
strides=flags.strides,
data_format='channels_last')(net)
# remove fake dim
net = tf.keras.backend.squeeze(net, axis=-1)
net = tf.keras.layers.Dropout(rate=flags.dropout1)(net)
for units, activation in zip(parse(flags.units2), parse(flags.act2)):
net = tf.keras.layers.Dense(units=units, activation=activation)(net)
net = tf.keras.layers.Dense(units=flags.label_count)(net)
return tf.keras.Model(input_audio, net)
def model(flags):
"""SVDF model.
This model is based on decomposition of a densely connected ops
into low rank filters.
It is based on paper
END-TO-END STREAMING KEYWORD SPOTTING https://arxiv.org/pdf/1812.02802.pdf
Args:
flags: data/model parameters
Returns:
Keras model for training
"""
input_audio = tf.keras.layers.Input(
shape=(flags.desired_samples,), batch_size=flags.batch_size)
net = speech_features.SpeechFeatures(
frame_size_ms=flags.window_size_ms,
frame_step_ms=flags.window_stride_ms,
sample_rate=flags.sample_rate,
use_tf_fft=flags.use_tf_fft,
preemph=flags.preemph,
window_type=flags.window_type,
feature_type=flags.feature_type,
mel_num_bins=flags.mel_num_bins,
mel_lower_edge_hertz=flags.mel_lower_edge_hertz,
mel_upper_edge_hertz=flags.mel_upper_edge_hertz,
mel_non_zero_only=flags.mel_non_zero_only,
fft_magnitude_squared=flags.fft_magnitude_squared,
dct_num_features=flags.dct_num_features)(
input_audio)
for i, (units1, memory_size, units2, dropout, activation) in enumerate(
zip(
parse(flags.svdf_units1), parse(flags.svdf_memory_size),
parse(flags.svdf_units2), parse(flags.svdf_dropout),
parse(flags.svdf_act))):
net = svdf.Svdf(
units1=units1,
memory_size=memory_size,
units2=units2,
dropout=dropout,
activation=activation,
pad=flags.svdf_pad,
name='svdf_%d' % i)(
net)
net = Stream(cell=tf.keras.layers.Flatten())(net)
net = tf.keras.layers.Dropout(rate=flags.dropout1)(net)
for units, activation in zip(parse(flags.units2), parse(flags.act2)):
net = tf.keras.layers.Dense(units=units, activation=activation)(net)
net = tf.keras.layers.Dense(units=flags.label_count)(net)
return tf.keras.Model(input_audio, net)
def model(flags):
"""LSTM model.
Similar model in papers:
Convolutional Recurrent Neural Networks for Small-Footprint Keyword Spotting
https://arxiv.org/pdf/1703.05390.pdf (with no conv layer)
Hello Edge: Keyword Spotting on Microcontrollers
https://arxiv.org/pdf/1711.07128.pdf
Args:
flags: data/model parameters
Returns:
Keras model for training
"""
input_audio = tf.keras.layers.Input(
shape=(flags.desired_samples,), batch_size=flags.batch_size)
net = speech_features.SpeechFeatures(
speech_features.SpeechFeatures.get_params(flags))(
input_audio)
for units, return_sequences, num_proj in zip(
parse(flags.lstm_units), parse(flags.return_sequences),
parse(flags.num_proj)):
net = LSTM(
units=units,
return_sequences=return_sequences,
stateful=flags.stateful,
use_peepholes=flags.use_peepholes,
num_proj=num_proj)(
net)
net = Stream(cell=tf.keras.layers.Flatten())(net)
net = tf.keras.layers.Dropout(rate=flags.dropout1)(net)
for units, activation in zip(parse(flags.units1), parse(flags.act1)):
net = tf.keras.layers.Dense(units=units, activation=activation)(net)
net = tf.keras.layers.Dense(units=flags.label_count)(net)
return tf.keras.Model(input_audio, net)
def model(flags):
"""CNN model.
It is based on paper:
Convolutional Neural Networks for Small-footprint Keyword Spotting
http://www.isca-speech.org/archive/interspeech_2015/papers/i15_1478.pdf
Args:
flags: data/model parameters
Returns:
Keras model for training
"""
input_audio = tf.keras.layers.Input(
shape=(flags.desired_samples,), batch_size=flags.batch_size)
net = speech_features.SpeechFeatures(
frame_size_ms=flags.window_size_ms,
frame_step_ms=flags.window_stride_ms,
sample_rate=flags.sample_rate,
use_tf_fft=flags.use_tf_fft,
preemph=flags.preemph,
window_type=flags.window_type,
feature_type=flags.feature_type,
mel_num_bins=flags.mel_num_bins,
mel_lower_edge_hertz=flags.mel_lower_edge_hertz,
mel_upper_edge_hertz=flags.mel_upper_edge_hertz,
mel_non_zero_only=flags.mel_non_zero_only,
fft_magnitude_squared=flags.fft_magnitude_squared,
dct_num_features=flags.dct_num_features)(
input_audio)
net = tf.keras.backend.expand_dims(net)
for filters, kernel_size, activation, dilation_rate, strides in zip(
parse(flags.cnn_filters), parse(flags.cnn_kernel_size),
parse(flags.cnn_act), parse(flags.cnn_dilation_rate),
parse(flags.cnn_strides)):
net = Stream(
cell=tf.keras.layers.Conv2D(
filters=filters,
kernel_size=kernel_size,
activation=activation,
dilation_rate=dilation_rate,
strides=strides))(
net)
net = Stream(cell=tf.keras.layers.Flatten())(net)
net = tf.keras.layers.Dropout(rate=flags.dropout1)(net)
for units, activation in zip(parse(flags.units2), parse(flags.act2)):
net = tf.keras.layers.Dense(units=units, activation=activation)(net)
net = tf.keras.layers.Dense(units=flags.label_count)(net)
return tf.keras.Model(input_audio, net)
def model(flags):
"""SVDF model.
This model is based on decomposition of a densely connected ops
into low rank filters.
It is based on paper
END-TO-END STREAMING KEYWORD SPOTTING https://arxiv.org/pdf/1812.02802.pdf
Args:
flags: data/model parameters
Returns:
Keras model for training
"""
input_audio = tf.keras.layers.Input(
shape=modes.get_input_data_shape(flags, modes.Modes.TRAINING),
batch_size=flags.batch_size)
net = input_audio
if flags.preprocess == 'raw':
# it is a self contained model, user need to feed raw audio only
net = speech_features.SpeechFeatures(
speech_features.SpeechFeatures.get_params(flags))(
net)
# for streaming mode it is better to use causal padding
padding = 'causal' if flags.svdf_pad else 'valid'
for i, (units1, memory_size, units2, dropout, activation) in enumerate(
zip(
utils.parse(flags.svdf_units1), utils.parse(flags.svdf_memory_size),
utils.parse(flags.svdf_units2), utils.parse(flags.svdf_dropout),
utils.parse(flags.svdf_act))):
net = svdf.Svdf(
units1=units1,
memory_size=memory_size,
units2=units2,
dropout=dropout,
activation=activation,
pad=padding,
name='svdf_%d' % i)(
net)
net = stream.Stream(cell=tf.keras.layers.Flatten())(net)
net = tf.keras.layers.Dropout(rate=flags.dropout1)(net)
for units, activation in zip(
utils.parse(flags.units2), utils.parse(flags.act2)):
net = tf.keras.layers.Dense(units=units, activation=activation)(net)
net = tf.keras.layers.Dense(units=flags.label_count)(net)
if flags.return_softmax:
net = tf.keras.layers.Activation('softmax')(net)
return tf.keras.Model(input_audio, net)
def model(flags):
"""Gated Recurrent Unit(GRU) model.
It is based on paper
Convolutional Recurrent Neural Networks for Small-Footprint Keyword Spotting
https://arxiv.org/pdf/1703.05390.pdf (with no conv layer)
Hello Edge: Keyword Spotting on Microcontrollers
https://arxiv.org/pdf/1711.07128.pdf
Args:
flags: data/model parameters
Returns:
Keras model for training
"""
input_audio = tf.keras.layers.Input(shape=modes.get_input_data_shape(
flags, modes.Modes.TRAINING),
batch_size=flags.batch_size)
net = input_audio
if flags.preprocess == 'raw':
# it is a self contained model, user need to feed raw audio only
net = speech_features.SpeechFeatures(
speech_features.SpeechFeatures.get_params(flags))(net)
for units, return_sequences in zip(parse(flags.gru_units),
parse(flags.return_sequences)):
net = GRU(units=units,
return_sequences=return_sequences,
stateful=flags.stateful)(net)
net = Stream(cell=tf.keras.layers.Flatten())(net)
net = tf.keras.layers.Dropout(rate=flags.dropout1)(net)
for units, activation in zip(parse(flags.units1), parse(flags.act1)):
net = tf.keras.layers.Dense(units=units, activation=activation)(net)
net = tf.keras.layers.Dense(units=flags.label_count)(net)
return tf.keras.Model(input_audio, net)
def model(flags):
"""CNN model.
It is based on paper:
Convolutional Neural Networks for Small-footprint Keyword Spotting
http://www.isca-speech.org/archive/interspeech_2015/papers/i15_1478.pdf
Model topology is similar with "Hello Edge: Keyword Spotting on
Microcontrollers" https://arxiv.org/pdf/1711.07128.pdf
Args:
flags: data/model parameters
Returns:
Keras model for training
"""
input_audio = tf.keras.layers.Input(shape=modes.get_input_data_shape(
flags, modes.Modes.TRAINING),
batch_size=flags.batch_size)
net = input_audio
if flags.preprocess == 'raw':
# it is a self contained model, user need to feed raw audio only
net = speech_features.SpeechFeatures(
speech_features.SpeechFeatures.get_params(flags))(net)
net = tf.keras.backend.expand_dims(net)
for filters, kernel_size, activation, dilation_rate, strides in zip(
utils.parse(flags.cnn_filters), utils.parse(flags.cnn_kernel_size),
utils.parse(flags.cnn_act), utils.parse(flags.cnn_dilation_rate),
utils.parse(flags.cnn_strides)):
net = stream.Stream(
cell=tf.keras.layers.Conv2D(filters=filters,
kernel_size=kernel_size,
activation=activation,
dilation_rate=dilation_rate,
strides=strides))(net)
net = stream.Stream(cell=tf.keras.layers.Flatten())(net)
net = tf.keras.layers.Dropout(rate=flags.dropout1)(net)
for units, activation in zip(utils.parse(flags.units2),
utils.parse(flags.act2)):
net = tf.keras.layers.Dense(units=units, activation=activation)(net)
net = tf.keras.layers.Dense(units=flags.label_count)(net)
if flags.return_softmax:
net = tf.keras.layers.Activation('softmax')(net)
return tf.keras.Model(input_audio, net)
def model(flags):
"""Temporal Convolution ResNet model.
It can be configured to reproduce model config as described in the paper below
Temporal Convolution for Real-time Keyword Spotting on Mobile Devices
https://arxiv.org/pdf/1904.03814.pdf
Args:
flags: data/model parameters
Returns:
Keras model for training
"""
tc_filters = parse(flags.tc_filters)
repeat_tc_convs = parse(flags.repeat_tc_convs)
kernel_sizes = parse(flags.kernel_sizes)
pool_sizes = parse(flags.pool_sizes)
dilations = parse(flags.dilations)
residuals = parse(flags.residuals)
if len(
set((len(repeat_tc_convs), len(kernel_sizes), len(pool_sizes),
len(dilations), len(residuals), len(tc_filters)))) != 1:
raise ValueError('all input lists have to be the same length')
input_audio = tf.keras.layers.Input(shape=modes.get_input_data_shape(
flags, modes.Modes.TRAINING),
batch_size=flags.batch_size)
net = input_audio
if flags.preprocess == 'raw':
# it is a self contained model, user need to feed raw audio only
net = speech_features.SpeechFeatures(
speech_features.SpeechFeatures.get_params(flags))(net)
# make it [batch, time, 1, feature]
net = tf.keras.backend.expand_dims(net, axis=2)
for filters, repeat, kernel_size, pool_size, dilation, residual in zip(
tc_filters, repeat_tc_convs, kernel_sizes, pool_sizes, dilations,
residuals):
net = resnet_block(net, repeat, kernel_size, filters, dilation,
residual, flags.padding_in_time, flags.dropout,
flags.activation)
if pool_size > 1:
net = tf.keras.layers.MaxPooling2D((pool_size, 1))(net)
net = stream.Stream(cell=tf.keras.layers.GlobalAveragePooling2D())(net)
net = tf.keras.layers.Dense(units=flags.label_count)(net)
if flags.return_softmax:
net = tf.keras.layers.Activation('softmax')(net)
return tf.keras.Model(input_audio, net)
def model(flags):
"""SVDF model.
This model is based on decomposition of a densely connected ops
into low rank filters.
It is based on paper
END-TO-END STREAMING KEYWORD SPOTTING https://arxiv.org/pdf/1812.02802.pdf
Args:
flags: data/model parameters
Returns:
Keras model for training
"""
input_audio = tf.keras.layers.Input(
shape=(flags.desired_samples,), batch_size=flags.batch_size)
net = speech_features.SpeechFeatures(
speech_features.SpeechFeatures.get_params(flags))(
input_audio)
for i, (units1, memory_size, units2, dropout, activation) in enumerate(
zip(
parse(flags.svdf_units1), parse(flags.svdf_memory_size),
parse(flags.svdf_units2), parse(flags.svdf_dropout),
parse(flags.svdf_act))):
net = svdf.Svdf(
units1=units1,
memory_size=memory_size,
units2=units2,
dropout=dropout,
activation=activation,
pad=flags.svdf_pad,
name='svdf_%d' % i)(
net)
net = Stream(cell=tf.keras.layers.Flatten())(net)
net = tf.keras.layers.Dropout(rate=flags.dropout1)(net)
for units, activation in zip(parse(flags.units2), parse(flags.act2)):
net = tf.keras.layers.Dense(units=units, activation=activation)(net)
net = tf.keras.layers.Dense(units=flags.label_count)(net)
return tf.keras.Model(input_audio, net)
def model(flags):
"""CNN model.
It is based on paper:
Convolutional Neural Networks for Small-footprint Keyword Spotting
http://www.isca-speech.org/archive/interspeech_2015/papers/i15_1478.pdf
Args:
flags: data/model parameters
Returns:
Keras model for training
"""
input_audio = tf.keras.layers.Input(shape=(flags.desired_samples, ),
batch_size=flags.batch_size)
net = speech_features.SpeechFeatures(
speech_features.SpeechFeatures.get_params(flags))(input_audio)
net = tf.keras.backend.expand_dims(net)
for filters, kernel_size, activation, dilation_rate, strides in zip(
parse(flags.cnn_filters), parse(flags.cnn_kernel_size),
parse(flags.cnn_act), parse(flags.cnn_dilation_rate),
parse(flags.cnn_strides)):
net = Stream(cell=tf.keras.layers.Conv2D(filters=filters,
kernel_size=kernel_size,
activation=activation,
dilation_rate=dilation_rate,
strides=strides))(net)
net = Stream(cell=tf.keras.layers.Flatten())(net)
net = tf.keras.layers.Dropout(rate=flags.dropout1)(net)
for units, activation in zip(parse(flags.units2), parse(flags.act2)):
net = tf.keras.layers.Dense(units=units, activation=activation)(net)
net = tf.keras.layers.Dense(units=flags.label_count)(net)
return tf.keras.Model(input_audio, net)
def model(flags):
"""Mobilenet model.
It is based on paper:
MobileNets: Efficient Convolutional Neural Networks for
Mobile Vision Applications https://arxiv.org/abs/1704.04861
It is applied on sequence in time, so only 1D filters applied
Args:
flags: data/model parameters
Returns:
Keras model for training
"""
input_audio = tf.keras.layers.Input(
shape=modes.get_input_data_shape(flags, modes.Modes.TRAINING),
batch_size=flags.batch_size)
net = input_audio
if flags.preprocess == 'raw':
# it is a self contained model, user need to feed raw audio only
net = speech_features.SpeechFeatures(
speech_features.SpeechFeatures.get_params(flags))(
net)
# [batch, time, feature]
net = tf.keras.backend.expand_dims(net, axis=2)
# [batch, time, feature, 1]
# it is convolutional block
net = tf.keras.layers.Conv2D(
filters=flags.cnn1_filters,
kernel_size=utils.parse(flags.cnn1_kernel_size),
padding='valid',
use_bias=False,
strides=utils.parse(flags.cnn1_strides))(
net)
net = tf.keras.layers.BatchNormalization(scale=flags.bn_scale)(net)
net = tf.keras.layers.ReLU(6.)(net)
# [batch, time, feature, filters]
for kernel_size, strides, filters in zip(
utils.parse(flags.ds_kernel_size), utils.parse(flags.ds_strides),
utils.parse(flags.cnn_filters)):
# it is depthwise convolutional block
net = tf.keras.layers.DepthwiseConv2D(
kernel_size,
padding='same' if strides == (1, 1) else 'valid',
depth_multiplier=1,
strides=strides,
use_bias=False)(
net)
net = tf.keras.layers.BatchNormalization(scale=flags.bn_scale)(net)
net = tf.keras.layers.ReLU(6.,)(net)
net = tf.keras.layers.Conv2D(
filters=filters, kernel_size=(1, 1),
padding='same',
use_bias=False,
strides=(1, 1))(net)
net = tf.keras.layers.BatchNormalization(scale=flags.bn_scale)(net)
net = tf.keras.layers.ReLU(6.)(net)
# [batch, time, feature, filters]
net = tf.keras.layers.GlobalAveragePooling2D()(net)
# [batch, filters]
net = tf.keras.layers.Dropout(flags.dropout)(net)
net = tf.keras.layers.Dense(flags.label_count)(net)
if flags.return_softmax:
net = tf.keras.layers.Activation('softmax')(net)
# [batch, label_count]
return tf.keras.Model(input_audio, net)
def model(flags):
"""Inception model.
It is based on paper:
Rethinking the Inception Architecture for Computer Vision
http://arxiv.org/abs/1512.00567
Args:
flags: data/model parameters
Returns:
Keras model for training
"""
input_audio = tf.keras.layers.Input(shape=modes.get_input_data_shape(
flags, modes.Modes.TRAINING),
batch_size=flags.batch_size)
net = input_audio
if flags.preprocess == 'raw':
# it is a self contained model, user need to feed raw audio only
net = speech_features.SpeechFeatures(
speech_features.SpeechFeatures.get_params(flags))(net)
# [batch, time, feature]
net = tf.keras.backend.expand_dims(net, axis=-1)
# [batch, time, feature, 1]
for filters in utils.parse(flags.cnn_filters0):
net = tf.keras.layers.SeparableConv2D(filters, (3, 3),
padding='valid',
use_bias=False)(net)
net = tf.keras.layers.BatchNormalization(scale=flags.bn_scale)(net)
net = tf.keras.layers.Activation('relu')(net)
net = tf.keras.layers.MaxPooling2D((3, 3), strides=(2, 2))(net)
# [batch, time, feature, filters]
filters = utils.parse(flags.cnn_filters0)[-1]
net = utils.conv2d_bn(net,
filters, (3, 1),
padding='valid',
scale=flags.bn_scale)
net = utils.conv2d_bn(net,
filters, (1, 3),
padding='valid',
scale=flags.bn_scale)
for stride, filters1, filters2 in zip(utils.parse(flags.cnn_strides),
utils.parse(flags.cnn_filters1),
utils.parse(flags.cnn_filters2)):
if stride > 1:
net = tf.keras.layers.MaxPooling2D((3, 3), strides=stride)(net)
branch1 = utils.conv2d_bn(net, filters2, (1, 1), scale=flags.bn_scale)
branch2 = utils.conv2d_bn(net, filters1, (1, 1), scale=flags.bn_scale)
branch2 = utils.conv2d_bn(branch2,
filters1, (3, 1),
scale=flags.bn_scale)
branch2 = utils.conv2d_bn(branch2,
filters2, (1, 3),
scale=flags.bn_scale)
branch3 = utils.conv2d_bn(net, filters1, (1, 1), scale=flags.bn_scale)
branch3 = utils.conv2d_bn(branch3,
filters1, (3, 1),
scale=flags.bn_scale)
branch3 = utils.conv2d_bn(branch3,
filters1, (1, 3),
scale=flags.bn_scale)
branch3 = utils.conv2d_bn(branch3,
filters1, (3, 1),
scale=flags.bn_scale)
branch3 = utils.conv2d_bn(branch3,
filters2, (1, 3),
scale=flags.bn_scale)
branch4 = tf.keras.layers.AveragePooling2D((3, 3),
strides=(1, 1),
padding='same')(net)
branch4 = utils.conv2d_bn(branch4,
filters2, (1, 1),
scale=flags.bn_scale)
net = tf.keras.layers.concatenate([branch1, branch2, branch3, branch4])
# [batch, time, feature, filters*4]
net = tf.keras.layers.GlobalAveragePooling2D()(net)
# [batch, filters*4]
net = tf.keras.layers.Dropout(flags.dropout)(net)
net = tf.keras.layers.Dense(flags.label_count)(net)
return tf.keras.Model(input_audio, net)
def model(flags):
"""BiRNN attention model.
It is based on paper:
A neural attention model for speech command recognition
https://arxiv.org/pdf/1808.08929.pdf
Depending on parameter rnn_type, model can be biLSTM or biGRU
Args:
flags: data/model parameters
Returns:
Keras model for training
"""
rnn_types = {'lstm': tf.keras.layers.LSTM, 'gru': tf.keras.layers.GRU}
if flags.rnn_type not in rnn_types:
ValueError('not supported RNN type ', flags.rnn_type)
rnn = rnn_types[flags.rnn_type]
input_audio = tf.keras.layers.Input(shape=(flags.desired_samples, ),
batch_size=flags.batch_size)
net = speech_features.SpeechFeatures(
speech_features.SpeechFeatures.get_params(flags))(input_audio)
net = tf.keras.backend.expand_dims(net)
for filters, kernel_size, activation, dilation_rate, strides in zip(
parse(flags.cnn_filters), parse(flags.cnn_kernel_size),
parse(flags.cnn_act), parse(flags.cnn_dilation_rate),
parse(flags.cnn_strides)):
net = tf.keras.layers.Conv2D(filters=filters,
kernel_size=kernel_size,
activation=activation,
dilation_rate=dilation_rate,
strides=strides,
padding='same')(net)
net = tf.keras.layers.BatchNormalization()(net)
shape = net.shape
# input net dimension: [batch, time, feature, channels]
# reshape dimension: [batch, time, feature * channels]
# so that GRU/RNN can process it
net = tf.keras.layers.Reshape((-1, shape[2] * shape[3]))(net)
# dims: [batch, time, feature]
for _ in range(flags.rnn_layers):
net = tf.keras.layers.Bidirectional(
rnn(flags.rnn_units, return_sequences=True, unroll=True))(net)
feature_dim = net.shape[-1]
middle = net.shape[1] // 2 # index of middle point of sequence
# feature vector at middle point [batch, feature]
mid_feature = net[:, middle, :]
# apply one projection layer with the same dim as input feature
query = tf.keras.layers.Dense(feature_dim)(mid_feature)
# attention weights [batch, time]
att_weights = tf.keras.layers.Dot(axes=[1, 2])([query, net])
att_weights = tf.keras.layers.Softmax(name='attSoftmax')(att_weights)
# apply attention weights [batch, feature]
net = tf.keras.layers.Dot(axes=[1, 1])([att_weights, net])
net = tf.keras.layers.Dropout(rate=flags.dropout1)(net)
for units, activation in zip(parse(flags.units2), parse(flags.act2)):
net = tf.keras.layers.Dense(units=units, activation=activation)(net)
net = tf.keras.layers.Dense(units=flags.label_count)(net)
return tf.keras.Model(input_audio, net)
def model(flags):
"""Inception model.
It is based on paper:
Rethinking the Inception Architecture for Computer Vision
http://arxiv.org/abs/1512.00567
Args:
flags: data/model parameters
Returns:
Keras model for training
"""
input_audio = tf.keras.layers.Input(shape=modes.get_input_data_shape(
flags, modes.Modes.TRAINING),
batch_size=flags.batch_size)
net = input_audio
if flags.preprocess == 'raw':
# it is a self contained model, user need to feed raw audio only
net = speech_features.SpeechFeatures(
speech_features.SpeechFeatures.get_params(flags))(net)
# [batch, time, feature]
net = tf.keras.backend.expand_dims(net, axis=2)
# [batch, time, 1, feature]
for stride, filters, kernel_size in zip(
utils.parse(flags.cnn1_strides), utils.parse(flags.cnn1_filters),
utils.parse(flags.cnn1_kernel_sizes)):
net = utils.conv2d_bn(net,
filters, (kernel_size, 1),
padding='valid',
scale=flags.bn_scale)
if stride > 1:
net = tf.keras.layers.MaxPooling2D((3, 1),
strides=(stride, 1))(net)
for stride, filters1, filters2, kernel_size in zip(
utils.parse(flags.cnn2_strides), utils.parse(flags.cnn2_filters1),
utils.parse(flags.cnn2_filters2),
utils.parse(flags.cnn2_kernel_sizes)):
branch1 = utils.conv2d_bn(net, filters1, (1, 1), scale=flags.bn_scale)
branch2 = utils.conv2d_bn(net, filters1, (1, 1), scale=flags.bn_scale)
branch2 = utils.conv2d_bn(branch2,
filters1, (kernel_size, 1),
scale=flags.bn_scale)
branch3 = utils.conv2d_bn(net, filters1, (1, 1), scale=flags.bn_scale)
branch3 = utils.conv2d_bn(branch3,
filters1, (kernel_size, 1),
scale=flags.bn_scale)
branch3 = utils.conv2d_bn(branch3,
filters1, (kernel_size, 1),
scale=flags.bn_scale)
net = tf.keras.layers.concatenate([branch1, branch2, branch3])
# [batch, time, 1, filters*4]
net = utils.conv2d_bn(net, filters2, (1, 1), scale=flags.bn_scale)
# [batch, time, 1, filters2]
if stride > 1:
net = tf.keras.layers.MaxPooling2D((3, 1),
strides=(stride, 1))(net)
net = tf.keras.layers.GlobalAveragePooling2D()(net)
# [batch, filters*4]
net = tf.keras.layers.Dropout(flags.dropout)(net)
net = tf.keras.layers.Dense(flags.label_count)(net)
if flags.return_softmax:
net = tf.keras.layers.Activation('softmax')(net)
return tf.keras.Model(input_audio, net)
def model(flags):
"""Xception model.
It is based on paper:
Xception: Deep Learning with Depthwise Separable Convolutions
https://arxiv.org/abs/1610.02357
Args:
flags: data/model parameters
Returns:
Keras model for training
"""
input_audio = tf.keras.layers.Input(shape=modes.get_input_data_shape(
flags, modes.Modes.TRAINING),
batch_size=flags.batch_size)
net = input_audio
if flags.preprocess == 'raw':
# it is a self contained model, user need to feed raw audio only
net = speech_features.SpeechFeatures(
speech_features.SpeechFeatures.get_params(flags))(net)
# [batch, time, feature]
net = tf.keras.backend.expand_dims(net, axis=-1)
# [batch, time, feature, 1]
# conv block
for kernel_size, stride, filters in zip(parse(flags.cnn1_kernel_size),
parse(flags.cnn1_strides),
parse(flags.cnn1_filters)):
net = tf.keras.layers.Conv2D(filters,
kernel_size,
strides=stride,
use_bias=False)(net)
net = tf.keras.layers.BatchNormalization(scale=flags.bn_scale)(net)
net = tf.keras.layers.Activation('relu')(net)
# [batch, time, feature, filters]
# first residual block
for filters in parse(flags.cnn2_filters):
residual = tf.keras.layers.Conv2D(filters, (1, 1),
strides=(2, 2),
padding='same',
use_bias=False)(net)
residual = tf.keras.layers.BatchNormalization(
scale=flags.bn_scale)(residual)
net = tf.keras.layers.SeparableConv2D(filters, (3, 3),
padding='same',
use_bias=False)(net)
net = tf.keras.layers.BatchNormalization(scale=flags.bn_scale)(net)
net = tf.keras.layers.MaxPooling2D((3, 3),
strides=(2, 2),
padding='same')(net)
net = tf.keras.layers.add([net, residual])
# [batch, time, feature, filters]
# second residual block
filters = parse(flags.cnn2_filters)[-1]
for _ in range(flags.cnn3_blocks):
residual = net
net = tf.keras.layers.Activation('relu')(net)
net = tf.keras.layers.SeparableConv2D(filters, (3, 3),
padding='same',
use_bias=False)(net)
net = tf.keras.layers.BatchNormalization(scale=flags.bn_scale)(net)
net = tf.keras.layers.Activation('relu')(net)
net = tf.keras.layers.SeparableConv2D(
filters,
(3, 3),
padding='same',
use_bias=False,
)(net)
net = tf.keras.layers.BatchNormalization(scale=flags.bn_scale)(net)
net = tf.keras.layers.Activation('relu')(net)
net = tf.keras.layers.SeparableConv2D(filters, (3, 3),
padding='same',
use_bias=False)(net)
net = tf.keras.layers.BatchNormalization(scale=flags.bn_scale)(net)
net = tf.keras.layers.add([net, residual])
# [batch, time, feature, filters]
net = tf.keras.layers.GlobalAveragePooling2D()(net)
# [batch, filters]
net = tf.keras.layers.Dropout(flags.dropout)(net)
net = tf.keras.layers.Dense(flags.label_count)(net)
# [batch, label_count]
return tf.keras.Model(input_audio, net)
def model(flags):
"""Inception resnet model.
It is based on paper:
Inception-v4, Inception-ResNet and the Impact of
Residual Connections on Learning https://arxiv.org/abs/1602.07261
Args:
flags: data/model parameters
Returns:
Keras model for training
"""
input_audio = tf.keras.layers.Input(
shape=modes.get_input_data_shape(flags, modes.Modes.TRAINING),
batch_size=flags.batch_size)
net = input_audio
if flags.preprocess == 'raw':
# it is a self contained model, user need to feed raw audio only
net = speech_features.SpeechFeatures(
speech_features.SpeechFeatures.get_params(flags))(
net)
# [batch, time, feature]
net = tf.keras.backend.expand_dims(net, axis=2)
# [batch, time, 1, feature]
for filters, kernel_size, stride in zip(
utils.parse(flags.cnn1_filters), utils.parse(flags.cnn1_kernel_sizes),
utils.parse(flags.cnn1_strides)):
net = utils.conv2d_bn(
net, filters, (kernel_size, 1), scale=flags.bn_scale, padding='valid')
if stride > 1:
net = tf.keras.layers.MaxPooling2D((3, 1), strides=(stride, 1))(net)
# [batch, time, 1, filters]
for stride, scale, filters_branch0, filters_branch1, filters_branch2, kernel_size in zip(
utils.parse(flags.cnn2_strides), utils.parse(flags.cnn2_scales),
utils.parse(flags.cnn2_filters_branch0),
utils.parse(flags.cnn2_filters_branch1),
utils.parse(flags.cnn2_filters_branch2),
utils.parse(flags.cnn2_kernel_sizes)):
net = inception_resnet_block(
net,
scale,
filters_branch0,
filters_branch1,
kernel_size,
bn_scale=flags.bn_scale)
net = utils.conv2d_bn(
net, filters_branch2, (1, 1), scale=flags.bn_scale, padding='valid')
if stride > 1:
net = tf.keras.layers.MaxPooling2D((3, 1),
strides=(stride, 1),
padding='valid')(
net)
# [batch, time, 1, filters]
net = tf.keras.layers.GlobalAveragePooling2D()(net)
# [batch, filters]
net = tf.keras.layers.Dropout(flags.dropout)(net)
net = tf.keras.layers.Dense(flags.label_count)(net)
if flags.return_softmax:
net = tf.keras.layers.Activation('softmax')(net)
return tf.keras.Model(input_audio, net)
def model(flags):
"""BiRNN multihead attention model.
It is based on paper:
Attention Is All You Need
https://papers.nips.cc/paper/7181-attention-is-all-you-need.pdf
A neural attention model for speech command recognition
https://arxiv.org/pdf/1808.08929.pdf
Depending on parameter rnn_type, model can be biLSTM or biGRU
Args:
flags: data/model parameters
Returns:
Keras model for training
"""
rnn_types = {'lstm': tf.keras.layers.LSTM, 'gru': tf.keras.layers.GRU}
if flags.rnn_type not in rnn_types:
ValueError('not supported RNN type ', flags.rnn_type)
rnn = rnn_types[flags.rnn_type]
input_audio = tf.keras.layers.Input(shape=modes.get_input_data_shape(
flags, modes.Modes.TRAINING),
batch_size=flags.batch_size)
net = input_audio
if flags.preprocess == 'raw':
# it is a self contained model, user need to feed raw audio only
net = speech_features.SpeechFeatures(
speech_features.SpeechFeatures.get_params(flags))(net)
net = tf.keras.backend.expand_dims(net)
for filters, kernel_size, activation, dilation_rate, strides in zip(
parse(flags.cnn_filters), parse(flags.cnn_kernel_size),
parse(flags.cnn_act), parse(flags.cnn_dilation_rate),
parse(flags.cnn_strides)):
net = tf.keras.layers.Conv2D(
filters=filters,
kernel_size=kernel_size,
activation=activation,
dilation_rate=dilation_rate,
strides=strides,
padding='same',
kernel_regularizer=tf.keras.regularizers.l2(flags.l2_weight_decay),
bias_regularizer=tf.keras.regularizers.l2(
flags.l2_weight_decay))(net)
net = tf.keras.layers.BatchNormalization()(net)
shape = net.shape
# input net dimension: [batch, time, feature, channels]
# reshape dimension: [batch, time, feature * channels]
# so that GRU/RNN can process it
net = tf.keras.layers.Reshape((-1, shape[2] * shape[3]))(net)
# dims: [batch, time, feature]
for _ in range(flags.rnn_layers):
net = tf.keras.layers.Bidirectional(
rnn(flags.rnn_units,
return_sequences=True,
unroll=True,
kernel_regularizer=tf.keras.regularizers.l2(
flags.l2_weight_decay),
bias_regularizer=tf.keras.regularizers.l2(
flags.l2_weight_decay)))(net)
feature_dim = net.shape[-1]
middle = net.shape[1] // 2 # index of middle point of sequence
# feature vector at middle point [batch, feature]
mid_feature = net[:, middle, :]
# prepare multihead attention
multiheads = []
for _ in range(flags.heads):
# apply one projection layer with the same dim as input feature
query = tf.keras.layers.Dense(
feature_dim,
kernel_regularizer=tf.keras.regularizers.l2(flags.l2_weight_decay),
bias_regularizer=tf.keras.regularizers.l2(
flags.l2_weight_decay))(mid_feature)
# attention weights [batch, time]
att_weights = tf.keras.layers.Dot(axes=[1, 2])([query, net])
att_weights = tf.keras.layers.Softmax()(att_weights)
# apply attention weights [batch, feature]
multiheads.append(tf.keras.layers.Dot(axes=[1, 1])([att_weights, net]))
net = tf.keras.layers.concatenate(multiheads)
net = tf.keras.layers.Dropout(rate=flags.dropout1)(net)
for units, activation in zip(parse(flags.units2), parse(flags.act2)):
net = tf.keras.layers.Dense(
units=units,
activation=activation,
kernel_regularizer=tf.keras.regularizers.l2(flags.l2_weight_decay),
bias_regularizer=tf.keras.regularizers.l2(
flags.l2_weight_decay))(net)
net = tf.keras.layers.Dense(units=flags.label_count)(net)
if flags.return_softmax:
net = tf.keras.layers.Activation('softmax')(net)
return tf.keras.Model(input_audio, net)
def model(flags):
"""Convolutional recurrent neural network (CRNN) model.
It is based on paper
Convolutional Recurrent Neural Networks for Small-Footprint Keyword Spotting
https://arxiv.org/pdf/1703.05390.pdf
Represented as sequence of Conv, RNN/GRU, FC layers.
Hello Edge: Keyword Spotting on Microcontrollers
https://arxiv.org/pdf/1711.07128.pdf
Args:
flags: data/model parameters
Returns:
Keras model for training
"""
input_audio = tf.keras.layers.Input(shape=(flags.desired_samples, ),
batch_size=flags.batch_size)
net = speech_features.SpeechFeatures(
frame_size_ms=flags.window_size_ms,
frame_step_ms=flags.window_stride_ms,
sample_rate=flags.sample_rate,
use_tf_fft=flags.use_tf_fft,
preemph=flags.preemph,
window_type=flags.window_type,
feature_type=flags.feature_type,
mel_num_bins=flags.mel_num_bins,
mel_lower_edge_hertz=flags.mel_lower_edge_hertz,
mel_upper_edge_hertz=flags.mel_upper_edge_hertz,
mel_non_zero_only=flags.mel_non_zero_only,
fft_magnitude_squared=flags.fft_magnitude_squared,
dct_num_features=flags.dct_num_features)(input_audio)
# expand dims for the next layer 2d conv
net = tf.keras.backend.expand_dims(net)
for filters, kernel_size, activation, dilation_rate, strides in zip(
parse(flags.cnn_filters), parse(flags.cnn_kernel_size),
parse(flags.cnn_act), parse(flags.cnn_dilation_rate),
parse(flags.cnn_strides)):
net = Stream(cell=tf.keras.layers.Conv2D(filters=filters,
kernel_size=kernel_size,
activation=activation,
dilation_rate=dilation_rate,
strides=strides))(net)
shape = net.shape
# input net dimension: [batch, time, feature, channels]
# reshape dimension: [batch, time, feature * channels]
# so that GRU/RNN can process it
net = tf.keras.layers.Reshape((-1, shape[2] * shape[3]))(net)
for units, return_sequences in zip(parse(flags.gru_units),
parse(flags.return_sequences)):
net = GRU(units=units,
return_sequences=return_sequences,
stateful=flags.stateful)(net)
net = Stream(cell=tf.keras.layers.Flatten())(net)
net = tf.keras.layers.Dropout(rate=flags.dropout1)(net)
for units, activation in zip(parse(flags.units1), parse(flags.act1)):
net = tf.keras.layers.Dense(units=units, activation=activation)(net)
net = tf.keras.layers.Dense(units=flags.label_count)(net)
return tf.keras.Model(input_audio, net)
def model(flags):
"""SVDF model with residual connections.
This model is based on decomposition of a densely connected ops
into low rank filters.
It is based on paper
END-TO-END STREAMING KEYWORD SPOTTING https://arxiv.org/pdf/1812.02802.pdf
In addition we added residual connection
Args:
flags: data/model parameters
Returns:
Keras model for training
"""
input_audio = tf.keras.layers.Input(shape=modes.get_input_data_shape(
flags, modes.Modes.TRAINING),
batch_size=flags.batch_size)
net = input_audio
if flags.preprocess == 'raw':
# it is a self contained model, user need to feed raw audio only
net = speech_features.SpeechFeatures(
speech_features.SpeechFeatures.get_params(flags))(net)
blocks_pool = parse(flags.blocks_pool)
if len(blocks_pool) != 3:
raise ValueError('number of pooling blocks has to be 3, but get: ',
len(blocks_pool))
# for streaming mode it is better to use causal padding
padding = 'causal' if flags.svdf_pad else 'valid'
# first residual block
number_of_blocks = len(parse(flags.block1_units1))
activations = [flags.activation] * number_of_blocks
activations[-1] = 'linear' # last layer is linear
residual = net
for i, (units1, memory_size, activation) in enumerate(
zip(parse(flags.block1_units1), parse(flags.block1_memory_size),
activations)):
# [batch, time, feature]
net = svdf.Svdf(units1=units1,
memory_size=memory_size,
units2=-1,
dropout=flags.svdf_dropout,
activation=activation,
pad=padding,
use_bias=flags.svdf_use_bias,
use_batch_norm=flags.use_batch_norm,
bn_scale=flags.bn_scale,
name='svdf_1_%d' % i)(net)
# number of channels in the last layer
units1_last = parse(flags.block1_units1)[-1]
# equivalent to 1x1 convolution
residual = tf.keras.layers.Dense(units1_last, use_bias=False)(residual)
residual = tf.keras.layers.BatchNormalization(
scale=flags.bn_scale)(residual)
# residual connection
net = tf.keras.layers.Add()([net, residual])
# [batch, time, feature]
net = tf.keras.layers.Activation(flags.activation)(net)
net = tf.keras.layers.MaxPool1D(3, strides=blocks_pool[0],
padding='valid')(net)
# second residual block
number_of_blocks = len(parse(flags.block2_units1))
activations = [flags.activation] * number_of_blocks
activations[-1] = 'linear' # last layer is linear
residual = net
for i, (units1, memory_size, activation) in enumerate(
zip(parse(flags.block2_units1), parse(flags.block2_memory_size),
activations)):
# [batch, time, feature]
net = svdf.Svdf(units1=units1,
memory_size=memory_size,
units2=-1,
dropout=flags.svdf_dropout,
activation=activation,
pad=padding,
use_bias=flags.svdf_use_bias,
use_batch_norm=flags.use_batch_norm,
bn_scale=flags.bn_scale,
name='svdf_2_%d' % i)(net)
# number of channels in the last layer
units1_last = parse(flags.block2_units1)[-1]
# equivalent to 1x1 convolution
residual = tf.keras.layers.Dense(units1_last, use_bias=False)(residual)
residual = tf.keras.layers.BatchNormalization(
scale=flags.bn_scale)(residual)
# residual connection
net = tf.keras.layers.Add()([net, residual])
net = tf.keras.layers.Activation(flags.activation)(net)
# [batch, time, feature]
net = tf.keras.layers.MaxPool1D(3, strides=blocks_pool[1],
padding='valid')(net)
# third residual block
number_of_blocks = len(parse(flags.block3_units1))
activations = [flags.activation] * number_of_blocks
activations[-1] = 'linear' # last layer is linear
residual = net
for i, (units1, memory_size, activation) in enumerate(
zip(parse(flags.block3_units1), parse(flags.block3_memory_size),
activations)):
net = svdf.Svdf(units1=units1,
memory_size=memory_size,
units2=-1,
dropout=flags.svdf_dropout,
activation=activation,
pad=padding,
use_bias=flags.svdf_use_bias,
use_batch_norm=flags.use_batch_norm,
bn_scale=flags.bn_scale,
name='svdf_3_%d' % i)(net)
# number of channels in the last layer
units1_last = parse(flags.block3_units1)[-1]
# equivalent to 1x1 convolution
residual = tf.keras.layers.Dense(units1_last, use_bias=False)(residual)
residual = tf.keras.layers.BatchNormalization(
scale=flags.bn_scale)(residual)
# residual connection
net = tf.keras.layers.Add()([net, residual])
net = tf.keras.layers.Activation(flags.activation)(net)
net = tf.keras.layers.MaxPool1D(3, strides=blocks_pool[2],
padding='valid')(net)
# [batch, time, feature]
# convert all feature to one vector
if flags.flatten:
net = tf.keras.layers.Flatten()(net)
else:
net = tf.keras.layers.GlobalAveragePooling1D()(net)
# [batch, feature]
net = tf.keras.layers.Dropout(rate=flags.dropout1)(net)
for units in parse(flags.units2):
net = tf.keras.layers.Dense(units=units,
activation=flags.activation)(net)
net = tf.keras.layers.Dense(units=flags.label_count)(net)
if flags.return_softmax:
net = tf.keras.layers.Activation('softmax')(net)
return tf.keras.Model(input_audio, net)
def model(flags):
"""BiRNN multihead attention model.
It is based on paper:
Attention Is All You Need
https://papers.nips.cc/paper/7181-attention-is-all-you-need.pdf
A neural attention model for speech command recognition
https://arxiv.org/pdf/1808.08929.pdf
Depending on parameter rnn_type, model can be biLSTM or biGRU
Args:
flags: data/model parameters
Returns:
Keras model for training
"""
rnn_types = {'lstm': tf.keras.layers.LSTM, 'gru': tf.keras.layers.GRU}
if flags.rnn_type not in rnn_types:
ValueError('not supported RNN type ', flags.rnn_type)
rnn = rnn_types[flags.rnn_type]
input_audio = tf.keras.layers.Input(shape=(flags.desired_samples, ),
batch_size=flags.batch_size)
net = speech_features.SpeechFeatures(
frame_size_ms=flags.window_size_ms,
frame_step_ms=flags.window_stride_ms,
sample_rate=flags.sample_rate,
use_tf_fft=flags.use_tf_fft,
preemph=flags.preemph,
window_type=flags.window_type,
feature_type=flags.feature_type,
mel_num_bins=flags.mel_num_bins,
mel_lower_edge_hertz=flags.mel_lower_edge_hertz,
mel_upper_edge_hertz=flags.mel_upper_edge_hertz,
mel_non_zero_only=flags.mel_non_zero_only,
fft_magnitude_squared=flags.fft_magnitude_squared,
dct_num_features=flags.dct_num_features)(input_audio)
net = tf.keras.backend.expand_dims(net)
for filters, kernel_size, activation, dilation_rate, strides in zip(
parse(flags.cnn_filters), parse(flags.cnn_kernel_size),
parse(flags.cnn_act), parse(flags.cnn_dilation_rate),
parse(flags.cnn_strides)):
net = tf.keras.layers.Conv2D(filters=filters,
kernel_size=kernel_size,
activation=activation,
dilation_rate=dilation_rate,
strides=strides,
padding='same')(net)
net = tf.keras.layers.BatchNormalization()(net)
shape = net.shape
# input net dimension: [batch, time, feature, channels]
# reshape dimension: [batch, time, feature * channels]
# so that GRU/RNN can process it
net = tf.keras.layers.Reshape((-1, shape[2] * shape[3]))(net)
# dims: [batch, time, feature]
for _ in range(flags.rnn_layers):
net = tf.keras.layers.Bidirectional(
rnn(flags.rnn_units, return_sequences=True, unroll=True))(net)
feature_dim = net.shape[-1]
middle = net.shape[1] // 2 # index of middle point of sequence
# feature vector at middle point [batch, feature]
mid_feature = net[:, middle, :]
# prepare multihead attention
multiheads = []
for _ in range(flags.heads):
# apply one projection layer with the same dim as input feature
query = tf.keras.layers.Dense(feature_dim)(mid_feature)
# attention weights [batch, time]
att_weights = tf.keras.layers.Dot(axes=[1, 2])([query, net])
att_weights = tf.keras.layers.Softmax()(att_weights)
# apply attention weights [batch, feature]
multiheads.append(tf.keras.layers.Dot(axes=[1, 1])([att_weights, net]))
net = tf.keras.layers.concatenate(multiheads)
net = tf.keras.layers.Dropout(rate=flags.dropout1)(net)
for units, activation in zip(parse(flags.units2), parse(flags.act2)):
net = tf.keras.layers.Dense(units=units, activation=activation)(net)
net = tf.keras.layers.Dense(units=flags.label_count)(net)
return tf.keras.Model(input_audio, net)
def model(flags):
"""Depthwise convolutional model.
It is based on paper:
MobileNets: Efficient Convolutional Neural Networks for
Mobile Vision Applications https://arxiv.org/abs/1704.04861
Model topology is similar with "Hello Edge: Keyword Spotting on
Microcontrollers" https://arxiv.org/pdf/1711.07128.pdf
Args:
flags: data/model parameters
Returns:
Keras model for training
"""
input_audio = tf.keras.layers.Input(shape=modes.get_input_data_shape(
flags, modes.Modes.TRAINING),
batch_size=flags.batch_size)
net = input_audio
if flags.preprocess == 'raw':
# it is a self contained model, user need to feed raw audio only
net = speech_features.SpeechFeatures(
speech_features.SpeechFeatures.get_params(flags))(net)
net = tf.keras.backend.expand_dims(net)
net = stream.Stream(cell=tf.keras.layers.Conv2D(
kernel_size=utils.parse(flags.cnn1_kernel_size),
dilation_rate=utils.parse(flags.cnn1_dilation_rate),
filters=flags.cnn1_filters,
padding=flags.cnn1_padding,
strides=utils.parse(flags.cnn1_strides)))(net)
net = tf.keras.layers.BatchNormalization(momentum=flags.bn_momentum,
center=flags.bn_center,
scale=flags.bn_scale,
renorm=flags.bn_renorm)(net)
net = tf.keras.layers.Activation('relu')(net)
for kernel_size, dw2_act, dilation_rate, strides, filters, cnn2_act in zip(
utils.parse(flags.dw2_kernel_size), utils.parse(flags.dw2_act),
utils.parse(flags.dw2_dilation_rate),
utils.parse(flags.dw2_strides), utils.parse(flags.cnn2_filters),
utils.parse(flags.cnn2_act)):
net = stream.Stream(
cell=tf.keras.layers.DepthwiseConv2D(kernel_size=kernel_size,
dilation_rate=dilation_rate,
padding=flags.dw2_padding,
strides=strides))(net)
net = tf.keras.layers.BatchNormalization(momentum=flags.bn_momentum,
center=flags.bn_center,
scale=flags.bn_scale,
renorm=flags.bn_renorm)(net)
net = tf.keras.layers.Activation(dw2_act)(net)
net = tf.keras.layers.Conv2D(kernel_size=(1, 1), filters=filters)(net)
net = tf.keras.layers.BatchNormalization(momentum=flags.bn_momentum,
center=flags.bn_center,
scale=flags.bn_scale,
renorm=flags.bn_renorm)(net)
net = tf.keras.layers.Activation(cnn2_act)(net)
net = stream.Stream(cell=tf.keras.layers.AveragePooling2D(
pool_size=(int(net.shape[1]), int(net.shape[2]))))(net)
net = stream.Stream(cell=tf.keras.layers.Flatten())(net)
net = tf.keras.layers.Dropout(rate=flags.dropout1)(net)
net = tf.keras.layers.Dense(units=flags.label_count)(net)
if flags.return_softmax:
net = tf.keras.layers.Activation('softmax')(net)
return tf.keras.Model(input_audio, net)
def model(flags):
"""MatchboxNet model.
It is based on paper
MatchboxNet: 1D Time-Channel Separable Convolutional Neural Network
Architecture for Speech Commands Recognition
https://arxiv.org/pdf/2004.08531.pdf
Args:
flags: data/model parameters
Returns:
Keras model for training
Raises:
ValueError: if any of input list has different length from any other;
or if padding is not supported
"""
ds_filters = parse(flags.ds_filters)
ds_repeat = parse(flags.ds_repeat)
ds_kernel_size = parse(flags.ds_kernel_size)
ds_stride = parse(flags.ds_stride)
ds_dilation = parse(flags.ds_dilation)
ds_residual = parse(flags.ds_residual)
ds_pool = parse(flags.ds_pool)
ds_padding = parse(flags.ds_padding)
ds_filter_separable = parse(flags.ds_filter_separable)
for l in (ds_repeat, ds_kernel_size, ds_stride, ds_dilation, ds_residual,
ds_pool, ds_padding, ds_filter_separable):
if len(ds_filters) != len(l):
raise ValueError('all input lists have to be the same length')
input_audio = tf.keras.layers.Input(shape=modes.get_input_data_shape(
flags, modes.Modes.TRAINING),
batch_size=flags.batch_size)
net = input_audio
if flags.preprocess == 'raw':
# it is a self contained model, user need to feed raw audio only
net = speech_features.SpeechFeatures(
speech_features.SpeechFeatures.get_params(flags))(net)
# make it [batch, time, 1, feature]
net = tf.keras.backend.expand_dims(net, axis=2)
# encoder
for filters, repeat, ksize, stride, sep, dilation, res, pool, pad in zip(
ds_filters, ds_repeat, ds_kernel_size, ds_stride,
ds_filter_separable, ds_dilation, ds_residual, ds_pool,
ds_padding):
net = resnet_block(net, repeat, ksize, filters, dilation, stride, sep,
res, pad, flags.dropout, flags.activation,
flags.ds_scale)
if pool > 1:
if flags.ds_max_pool:
net = tf.keras.layers.MaxPooling2D(pool_size=(pool, 1),
strides=(pool, 1))(net)
else:
net = tf.keras.layers.AveragePooling2D(pool_size=(pool, 1),
strides=(pool, 1))(net)
# decoder
net = stream.Stream(cell=tf.keras.layers.GlobalAveragePooling2D())(net)
net = tf.keras.layers.Flatten()(net)
net = tf.keras.layers.Dense(units=flags.label_count)(net)
if flags.return_softmax:
net = tf.keras.layers.Activation('softmax')(net)
return tf.keras.Model(input_audio, net)
