def cbhg(inputs, K, projections, depth, is_training, scope):
r"""Returns the 1D Convolution Bank Highwaynet bindirectional
GRU (CBHG) module.
Args:
inputs (nn.Variable): NNabla Variable of shape (B, C, T).
K (int): Maximum kernel size.
projections (list of int): A list of channels.
depth (int): A depth. This should be an even number.
is_training (bool): Whether training mode is activated.
scope (str): The parameter scope name.
Returns:
nn.Variable: Output variable.
"""
with nn.parameter_scope(scope):
# Convolution bank: concatenate channels from all 1D convolutions
with nn.parameter_scope('conv_bank'):
conv = partial(conv1d,
inputs,
channels=128,
activation=F.relu,
is_training=is_training)
conv_outputs = [
conv(kernel_size=k, scope=f'conv1d_{k}')
for k in range(1, K + 1)
]
conv_outputs = F.concatenate(*conv_outputs, axis=1)
# make sure a valid input to max_pooling
x = F.pad(conv_outputs, (0, ) * 5 + (1, ), mode='constant')
# Maxpooling: reshape is needed because nnabla does support 1D pooling
maxpool_output = F.max_pooling(x.reshape(x.shape + (1, )),
kernel=(2, 1),
stride=(1,
1)).reshape(conv_outputs.shape)
# Two projection layers:
proj1_output = conv1d(maxpool_output,
kernel_size=3,
channels=projections[0],
activation=F.relu,
is_training=is_training,
scope='proj_1')
proj2_output = conv1d(proj1_output,
kernel_size=3,
channels=projections[1],
activation=None,
is_training=is_training,
scope='proj_2')
# Residual connection:
highway_input = proj2_output + inputs
assert depth % 2 == 0
half_depth = depth // 2
with nn.parameter_scope('highwaynet'):
# transposing to shape (B, T, C)
highway_input = F.transpose(highway_input, (0, 2, 1))
# Handle dimensionality mismatch:
if highway_input.shape[2] != half_depth:
highway_input = PF.affine(highway_input,
half_depth,
base_axis=2,
name='adjust_dim')
# 4-layer HighwayNet:
for i in range(4):
highway_input = highwaynet(highway_input,
half_depth,
scope=f'highway_{i+1}')
with nn.parameter_scope('rnn_net'):
# transpose to shape (T, B, C)
rnn_input = F.transpose(highway_input, (1, 0, 2))
outputs, _ = PF.gru(rnn_input,
F.constant(shape=(2, 2, rnn_input.shape[1],
half_depth)),
training=is_training,
bidirectional=True) # (T, B, C)
return outputs
def test_pf_gru_execution(g_rng, inshape, w0_init, w_init, b_init, num_layers,
dropout, bidirectional, with_bias, hidden_size,
training, fix_parameters, rng, ctx, func_name):
with nn.context_scope(ctx):
if func_name == "GRU":
pytest.skip("Not implemented in CPU.")
num_directions = 2 if bidirectional else 1
w0_shape = (num_directions, 3, hidden_size, inshape[2] + hidden_size)
w_shape = (max(1, num_layers - 1), num_directions, 3, hidden_size,
num_directions * hidden_size + hidden_size)
b_shape = (num_layers, num_directions, 4, hidden_size)
w0_init = process_param_init(w0_init, w0_shape, g_rng)
w_init = process_param_init(w_init, w_shape, g_rng)
b_init = process_param_init(b_init, b_shape, g_rng)
rng = process_rng(rng)
kw = {}
insert_if_not_none(kw, 'w0_init', w0_init)
insert_if_not_none(kw, 'w_init', w_init)
insert_if_not_none(kw, 'b_init', b_init)
insert_if_not_default(kw, 'num_layers', num_layers, 1)
insert_if_not_default(kw, 'dropout', dropout, 0.0)
insert_if_not_default(kw, 'bidirectional', bidirectional, False)
insert_if_not_default(kw, 'training', training, True)
insert_if_not_none(kw, 'rng', rng)
insert_if_not_default(kw, 'with_bias', with_bias, True)
insert_if_not_default(kw, 'fix_parameters', fix_parameters, False)
x = nn.Variable.from_numpy_array(g_rng.randn(*inshape))
h = nn.Variable.from_numpy_array(
g_rng.randn(*(num_layers, num_directions, inshape[1],
hidden_size)))
# Check execution
y, hn = PF.gru(x, h, **kw)
y.forward()
if training:
y.backward()
# Check values
# TODO
# Check args
assert y.parent.info.type_name == 'GRU'
args = y.parent.info.args
# Check created parameters
assert y.parent.inputs[0] == x
assert y.parent.inputs[1] == h
w0 = nn.get_parameters()['gru/weight_l0']
assert w0.shape == w0_shape
assert w0.need_grad
assert y.parent.inputs[2].need_grad == (not fix_parameters)
if isinstance(w0_init, np.ndarray):
assert np.allclose(w0_init, w0.d)
if num_layers > 1:
w = nn.get_parameters()['gru/weight']
assert w.shape == w_shape
assert w.need_grad
assert y.parent.inputs[3].need_grad == (not fix_parameters)
if isinstance(w_init, np.ndarray):
assert np.allclose(w_init, w.d)
if with_bias:
b = nn.get_parameters()['gru/bias']
assert b.shape == b_shape
assert b.need_grad
if num_layers > 1:
assert y.parent.inputs[4].need_grad == (not fix_parameters)
else:
assert y.parent.inputs[3].need_grad == (not fix_parameters)
if isinstance(b_init, np.ndarray):
assert np.allclose(b_init, b.d)
def call(self, memory, inputs=None):
r"""Return mel-spectrogram and attention matrix.
Args:
memory(nn.Variable): A 3D tensor of shape (T, B, C).
inputs(nn.Variable, optional): A 3D tensor with shape of
[B, T/r, n_mels(*r)]. Shifted log melspectrogram of sound files.
Defaults to None.
Returns:
nn.Variable: The synthetic mel-spectrograms of shape
(B, Ty/r, r*n_mels).
nn.Variable: The attention matrix of shape
(B, Tx, Ty).
References:
- https://github.com/Kyubyong/tacotron/
"""
hp = self._hparams
bz, mel_shape = hp.batch_size, hp.n_mels * hp.r
encoder_dim = hp.encoder_embedding_dim
# initialize input tensor
input = F.constant(shape=(bz, 1, mel_shape))
# initialize hidden states
context = F.constant(shape=(bz, 1, hp.attention_dim))
hidden = F.constant(shape=(1, 1, bz, encoder_dim))
h_gru = [
F.constant(shape=(1, 1, bz, encoder_dim)),
F.constant(shape=(1, 1, bz, encoder_dim))
]
outputs, attends = [], []
for i in range(hp.n_frames):
if i > 0:
input = (outputs[-1] if inputs is None else inputs[:,
i - 1:i, :])
# feed a prenet to the input
input = prenet(input,
layer_sizes=hp.prenet_channels,
is_training=self.training,
scope='prenet_decoder') # (bz, 1, C)
# concat the input and context vector
input = F.concatenate(input, context) # (bz, 1, 384)
with nn.parameter_scope('rnn_attention'):
# calculate the output
output, hidden = PF.gru(
input.reshape((1, bz, -1)),
hidden,
training=self.training,
bidirectional=False) # (1, bz, 256), (1, 1, bz, 256)
# compute the context and attention vectors
context, attend = Bahdanau_attention(
F.transpose(hidden[0], (1, 0, 2)),
memory,
out_features=hp.attention_dim,
scope='Bahdanau_attention') # (bz, 1, 256), (bz, 1, T)
with nn.parameter_scope('rnn_decoder'):
# concat RNN output and attention context vector
with nn.parameter_scope('project_to_decoder'):
output = F.concatenate(output,
F.transpose(context, (1, 0, 2)),
axis=2)
output = PF.affine(output, encoder_dim,
base_axis=2) # (1, bz, 256)
# decoder RNN with residual connection
for j in range(2):
with nn.parameter_scope(f'gru_resisidual_{j}'):
out, h_gru[j] = PF.gru(output,
h_gru[j],
training=self.training,
bidirectional=False)
output += out # (1, bz, 256)
# projector to mels
with nn.parameter_scope('project_to_mel'):
output = F.transpose(output, (1, 0, 2))
# (bz, 1, n_mels*r)
output = PF.affine(output, mel_shape, base_axis=2)
outputs.append(output)
attends.append(attend)
outputs = F.concatenate(*outputs, axis=1) # (B, T2, C2)
attends = F.concatenate(*attends, axis=1) # (B, T2, T1)
return outputs, attends