def multi_conv_res(x, padding, name, layers, hparams, mask=None, source=None):
"""A stack of separable convolution blocks with residual connections."""
with tf.variable_scope(name):
padding_bias = None
if mask is not None:
padding_bias = (1.0 -
mask) * -1e9 # Bias to not attend to padding.
if padding == "LEFT": # Do not mask anything when left-padding.
mask = None
if (hparams.kernel_scheme in _KERNEL_SCHEMES
and hparams.dilation_scheme in _DILATION_SCHEMES):
kernels = _KERNEL_SCHEMES[hparams.kernel_scheme]
dilations = _DILATION_SCHEMES[hparams.dilation_scheme]
dilations_and_kernels = list(zip(dilations, kernels))
dilations_and_kernels1 = dilations_and_kernels[:2]
dilations_and_kernels2 = dilations_and_kernels[2:]
else:
k = (hparams.kernel_height, hparams.kernel_width)
k2 = (hparams.large_kernel_size, 1)
dilations_and_kernels1 = [((1, 1), k), ((1, 1), k)]
dilations_and_kernels2 = [((1, 1), k2), ((4, 4), k2)]
separabilities1 = [hparams.separability, hparams.separability]
separabilities2 = [hparams.separability] * len(dilations_and_kernels2)
if hparams.separability < 0:
separabilities1 = [hparams.separability - 1, hparams.separability]
separabilities2 = [
hparams.separability - i
for i in reversed(range(len(dilations_and_kernels2)))
]
norm_fn = get_norm(hparams)
for layer in xrange(layers):
with tf.variable_scope("layer_%d" % layer):
y = common_layers.subseparable_conv_block(
x,
hparams.hidden_size,
dilations_and_kernels1,
normalizer_fn=norm_fn,
padding=padding,
mask=mask,
separabilities=separabilities1,
name="residual1")
x += common_layers.subseparable_conv_block(
x + y,
hparams.hidden_size,
dilations_and_kernels2,
normalizer_fn=norm_fn,
padding=padding,
mask=mask,
separabilities=separabilities2,
name="residual2") + y
if source is not None and hparams.attention_type != "none":
x += attention(x,
source,
norm_fn,
hparams,
bias=padding_bias)
if mask is not None:
x *= mask
return tf.nn.dropout(x, 1.0 - hparams.dropout)
def multi_conv_res(x, padding, name, layers, hparams, train,
mask=None, source=None):
"""A stack of separable convolution blocks with residual connections."""
with tf.variable_scope(name):
padding_bias = None
if mask is not None:
padding_bias = (1.0 - mask) * -1e9 # Bias to not attend to padding.
if padding == "LEFT": # Do not mask anything when left-padding.
mask = None
if (hparams.kernel_scheme in _KERNEL_SCHEMES and
hparams.dilation_scheme in _DILATION_SCHEMES):
kernels = _KERNEL_SCHEMES[hparams.kernel_scheme]
dilations = _DILATION_SCHEMES[hparams.dilation_scheme]
dilations_and_kernels = list(zip(dilations, kernels))
dilations_and_kernels1 = dilations_and_kernels[:2]
dilations_and_kernels2 = dilations_and_kernels[2:]
else:
k = (hparams.kernel_height, hparams.kernel_width)
k2 = (hparams.large_kernel_size, 1)
dilations_and_kernels1 = [((1, 1), k), ((1, 1), k)]
dilations_and_kernels2 = [((1, 1), k2), ((4, 4), k2)]
separabilities1 = [hparams.separability, hparams.separability]
separabilities2 = [hparams.separability] * len(dilations_and_kernels2)
if hparams.separability < 0:
separabilities1 = [hparams.separability - 1, hparams.separability]
separabilities2 = [
hparams.separability - i
for i in reversed(range(len(dilations_and_kernels2)))
]
norm_fn = get_norm(hparams)
for layer in xrange(layers):
with tf.variable_scope("layer_%d" % layer):
y = common_layers.subseparable_conv_block(
x,
hparams.hidden_size,
dilations_and_kernels1,
normalizer_fn=norm_fn,
padding=padding,
mask=mask,
separabilities=separabilities1,
name="residual1")
x += common_layers.subseparable_conv_block(
x + y,
hparams.hidden_size,
dilations_and_kernels2,
normalizer_fn=norm_fn,
padding=padding,
mask=mask,
separabilities=separabilities2,
name="residual2") + y
if source is not None and hparams.attention_type != "none":
x += attention(x, source, norm_fn, hparams, train, bias=padding_bias)
if mask is not None:
x *= mask
return tf.nn.dropout(x, 1.0 - hparams.dropout * tf.to_float(train))
def attention(targets_shifted,
inputs_encoded,
norm_fn,
hparams,
train,
bias=None):
"""Complete attention layer with preprocessing."""
separabilities = [hparams.separability, hparams.separability]
if hparams.separability < 0:
separabilities = [hparams.separability - 1, hparams.separability]
targets_timed = common_layers.subseparable_conv_block(
common_layers.add_timing_signal(targets_shifted),
hparams.hidden_size, [((1, 1), (5, 1)), ((4, 1), (5, 1))],
normalizer_fn=norm_fn,
padding="LEFT",
separabilities=separabilities,
name="targets_time")
if hparams.attention_type == "transformer":
targets_timed = tf.squeeze(targets_timed, 2)
target_shape = tf.shape(targets_timed)
targets_segment = tf.zeros([target_shape[0], target_shape[1]])
target_attention_bias = common_attention.attention_bias(
targets_segment, targets_segment, lower_triangular=True)
inputs_attention_bias = tf.zeros([
tf.shape(inputs_encoded)[0], hparams.num_heads,
tf.shape(targets_segment)[1],
tf.shape(inputs_encoded)[1]
])
attention_dropout = hparams.attention_dropout * tf.to_float(train)
qv = common_attention.multihead_attention(targets_timed,
None,
target_attention_bias,
hparams.hidden_size,
hparams.hidden_size,
hparams.hidden_size,
hparams.num_heads,
attention_dropout,
name="self_attention",
summaries=False)
qv = common_attention.multihead_attention(qv,
inputs_encoded,
inputs_attention_bias,
hparams.hidden_size,
hparams.hidden_size,
hparams.hidden_size,
hparams.num_heads,
attention_dropout,
name="encdec_attention",
summaries=False)
return tf.expand_dims(qv, 2)
elif hparams.attention_type == "simple":
targets_with_attention = common_layers.simple_attention(
targets_timed, inputs_encoded, bias=bias, summaries=False)
return norm_fn(targets_shifted + targets_with_attention,
name="attn_norm")
def residual_block(x, hparams):
"""A stack of convolution blocks with residual connection."""
k = (hparams.kernel_height, hparams.kernel_width)
dilations_and_kernels = [((1, 1), k) for _ in xrange(3)]
y = common_layers.subseparable_conv_block(x,
hparams.hidden_size,
dilations_and_kernels,
padding="SAME",
separability=0,
name="residual_block")
x = common_layers.layer_norm(x + y, hparams.hidden_size, name="lnorm")
return tf.nn.dropout(x, 1.0 - hparams.dropout)
def attention(targets_shifted, inputs_encoded, norm_fn, hparams, train,
bias=None):
"""Complete attention layer with preprocessing."""
separabilities = [hparams.separability, hparams.separability]
if hparams.separability < 0:
separabilities = [hparams.separability - 1, hparams.separability]
targets_timed = common_layers.subseparable_conv_block(
common_layers.add_timing_signal(targets_shifted),
hparams.hidden_size, [((1, 1), (5, 1)), ((4, 1), (5, 1))],
normalizer_fn=norm_fn,
padding="LEFT",
separabilities=separabilities,
name="targets_time")
if hparams.attention_type == "transformer":
targets_timed = tf.squeeze(targets_timed, 2)
target_shape = tf.shape(targets_timed)
targets_segment = tf.zeros([target_shape[0], target_shape[1]])
target_attention_bias = common_attention.attention_bias(
targets_segment, targets_segment, lower_triangular=True)
inputs_attention_bias = tf.zeros([
tf.shape(inputs_encoded)[0], hparams.num_heads,
tf.shape(targets_segment)[1],
tf.shape(inputs_encoded)[1]
])
attention_dropout = hparams.attention_dropout * tf.to_float(train)
qv = common_attention.multihead_attention(
targets_timed,
None,
target_attention_bias,
hparams.hidden_size,
hparams.hidden_size,
hparams.hidden_size,
hparams.num_heads,
attention_dropout,
name="self_attention",
summaries=False)
qv = common_attention.multihead_attention(
qv,
inputs_encoded,
inputs_attention_bias,
hparams.hidden_size,
hparams.hidden_size,
hparams.hidden_size,
hparams.num_heads,
attention_dropout,
name="encdec_attention",
summaries=False)
return tf.expand_dims(qv, 2)
elif hparams.attention_type == "simple":
targets_with_attention = common_layers.simple_attention(
targets_timed, inputs_encoded, bias=bias, summaries=False)
return norm_fn(targets_shifted + targets_with_attention, name="attn_norm")
def residual_block(x, hparams, train):
"""A stack of convolution blocks with residual connection."""
k = (hparams.kernel_height, hparams.kernel_width)
dilations_and_kernels = [((1, 1), k) for _ in xrange(3)]
y = common_layers.subseparable_conv_block(
x,
hparams.hidden_size,
dilations_and_kernels,
padding="SAME",
separability=0,
name="residual_block")
x = common_layers.layer_norm(x + y, hparams.hidden_size, name="lnorm")
return tf.nn.dropout(x, 1.0 - hparams.dropout * tf.to_float(train))
def testSubSeparableConvBlock(self):
for sep in [0, 1, 2, 4]:
x = np.random.rand(5, 7, 1, 12)
with self.test_session() as session:
with tf.variable_scope("sep_%d" % sep):
y = common_layers.subseparable_conv_block(
tf.constant(x, dtype=tf.float32),
16, [(1, (3, 3)), (1, (3, 3))],
padding="SAME",
separability=sep)
session.run(tf.global_variables_initializer())
res = session.run(y)
self.assertEqual(res.shape, (5, 7, 1, 16))
def testSubSeparableConvBlock(self):
for sep in [0, 1, 2, 4]:
x = np.random.rand(5, 7, 1, 12)
with self.test_session() as session:
with tf.variable_scope("sep_%d" % sep):
y = common_layers.subseparable_conv_block(
tf.constant(x, dtype=tf.float32),
16, [(1, (3, 3)), (1, (3, 3))],
padding="SAME",
separability=sep)
session.run(tf.global_variables_initializer())
res = session.run(y)
self.assertEqual(res.shape, (5, 7, 1, 16))
def residual_module(x, hparams, train, n, sep):
"""A stack of convolution blocks with residual connection."""
k = (hparams.kernel_height, hparams.kernel_width)
dilations_and_kernels = [((1, 1), k) for _ in xrange(n)]
with tf.variable_scope("residual_module%d_sep%d" % (n, sep)):
y = common_layers.subseparable_conv_block(x,
hparams.hidden_size,
dilations_and_kernels,
padding="SAME",
separability=sep,
name="block")
x = common_layers.layer_norm(x + y, hparams.hidden_size, name="lnorm")
return tf.nn.dropout(x, 1.0 - hparams.dropout * tf.to_float(train))
def conv_res_step(x, hparams, padding, mask):
"""One step of convolutions and mid-residual."""
k = (hparams.kernel_height, hparams.kernel_width)
k2 = (hparams.large_kernel_size, 1)
dilations_and_kernels1 = [((1, 1), k), ((1, 1), k)]
dilations_and_kernels2 = [((1, 1), k2), ((4, 4), k2)]
with tf.variable_scope("conv_res_step"):
y = common_layers.subseparable_conv_block(x,
hparams.filter_size,
dilations_and_kernels1,
padding=padding,
mask=mask,
separabilities=0,
name="residual1")
y = tf.nn.dropout(y, 1.0 - hparams.dropout)
return common_layers.subseparable_conv_block(y,
hparams.hidden_size,
dilations_and_kernels2,
padding=padding,
mask=mask,
separabilities=0,
name="residual2")
def slicenet_middle(inputs_encoded, targets, target_space_emb, mask, hparams,
train):
"""Middle part of slicenet, connecting encoder and decoder."""
norm_fn = get_norm(hparams)
# Flatten targets and embed target_space_id.
targets_flat = tf.expand_dims(common_layers.flatten4d3d(targets), axis=2)
target_space_emb = tf.tile(target_space_emb,
[tf.shape(targets_flat)[0], 1, 1, 1])
# Calculate similarity loss (but don't run if not needed).
if len(hparams.problems) > 1 and hparams.sim_loss_mult > 0.00001:
targets_timed = common_layers.add_timing_signal(targets_flat)
extra_layers = int(hparams.num_hidden_layers * 1.5)
with tf.variable_scope(tf.get_variable_scope(), reuse=True):
targets_encoded = multi_conv_res(targets_timed, "SAME", "encoder",
extra_layers, hparams, train)
with tf.variable_scope("similarity_loss"):
similarity_loss = similarity_cost(inputs_encoded, targets_encoded)
similarity_loss *= hparams.sim_loss_mult
else:
similarity_loss = 0.0
# Use attention from each target to look at input and retrieve.
targets_shifted = common_layers.shift_left(targets_flat,
pad_value=target_space_emb)
if hparams.attention_type == "none":
targets_with_attention = tf.zeros_like(targets_shifted)
else:
inputs_padding_bias = (1.0 -
mask) * -1e9 # Bias to not attend to padding.
targets_with_attention = attention(targets_shifted,
inputs_encoded,
norm_fn,
hparams,
train,
bias=inputs_padding_bias)
# Positional targets: merge attention and raw.
kernel = (hparams.kernel_height, hparams.kernel_width)
targets_merged = common_layers.subseparable_conv_block(
tf.concat([targets_with_attention, targets_shifted], axis=3),
hparams.hidden_size, [((1, 1), kernel)],
normalizer_fn=norm_fn,
padding="LEFT",
separability=4,
name="targets_merge")
return targets_merged, similarity_loss
def slicenet_middle(inputs_encoded, targets, target_space_emb, mask,
hparams, train):
"""Middle part of slicenet, connecting encoder and decoder."""
norm_fn = get_norm(hparams)
# Flatten targets and embed target_space_id.
targets_flat = tf.expand_dims(common_layers.flatten4d3d(targets), axis=2)
target_space_emb = tf.tile(target_space_emb,
[tf.shape(targets_flat)[0], 1, 1, 1])
# Calculate similarity loss (but don't run if not needed).
if len(hparams.problems) > 1 and hparams.sim_loss_mult > 0.00001:
targets_timed = common_layers.add_timing_signal(targets_flat)
extra_layers = int(hparams.num_hidden_layers * 1.5)
with tf.variable_scope(tf.get_variable_scope(), reuse=True):
targets_encoded = multi_conv_res(targets_timed, "SAME", "encoder",
extra_layers, hparams, train)
with tf.variable_scope("similarity_loss"):
similarity_loss = similarity_cost(inputs_encoded, targets_encoded)
similarity_loss *= hparams.sim_loss_mult
else:
similarity_loss = 0.0
# Use attention from each target to look at input and retrieve.
targets_shifted = common_layers.shift_left(
targets_flat, pad_value=target_space_emb)
if hparams.attention_type == "none":
targets_with_attention = tf.zeros_like(targets_shifted)
else:
inputs_padding_bias = (1.0 - mask) * -1e9 # Bias to not attend to padding.
targets_with_attention = attention(
targets_shifted, inputs_encoded, norm_fn, hparams, train,
bias=inputs_padding_bias)
# Positional targets: merge attention and raw.
kernel = (hparams.kernel_height, hparams.kernel_width)
targets_merged = common_layers.subseparable_conv_block(
tf.concat([targets_with_attention, targets_shifted], axis=3),
hparams.hidden_size, [((1, 1), kernel)],
normalizer_fn=norm_fn,
padding="LEFT",
separability=4,
name="targets_merge")
return targets_merged, similarity_loss
