MockingBird/models/vocoder/fregan/modules.py

import torch
import torch.nn.functional as F

class KernelPredictor(torch.nn.Module):
    ''' Kernel predictor for the location-variable convolutions
    '''

    def __init__(self,
                 cond_channels,
                 conv_in_channels,
                 conv_out_channels,
                 conv_layers,
                 conv_kernel_size=3,
                 kpnet_hidden_channels=64,
                 kpnet_conv_size=3,
                 kpnet_dropout=0.0,
                 kpnet_nonlinear_activation="LeakyReLU",
                 kpnet_nonlinear_activation_params={"negative_slope": 0.1}
                 ):
        '''
        Args:
            cond_channels (int): number of channel for the conditioning sequence,
            conv_in_channels (int): number of channel for the input sequence,
            conv_out_channels (int): number of channel for the output sequence,
            conv_layers (int):
            kpnet_
        '''
        super().__init__()

        self.conv_in_channels = conv_in_channels
        self.conv_out_channels = conv_out_channels
        self.conv_kernel_size = conv_kernel_size
        self.conv_layers = conv_layers

        l_w = conv_in_channels * conv_out_channels * conv_kernel_size * conv_layers
        l_b = conv_out_channels * conv_layers

        padding = (kpnet_conv_size - 1) // 2
        self.input_conv = torch.nn.Sequential(
            torch.nn.Conv1d(cond_channels, kpnet_hidden_channels, 5, padding=(5 - 1) // 2, bias=True),
            getattr(torch.nn, kpnet_nonlinear_activation)(**kpnet_nonlinear_activation_params),
        )

        self.residual_conv = torch.nn.Sequential(
            torch.nn.Dropout(kpnet_dropout),
            torch.nn.Conv1d(kpnet_hidden_channels, kpnet_hidden_channels, kpnet_conv_size, padding=padding, bias=True),
            getattr(torch.nn, kpnet_nonlinear_activation)(**kpnet_nonlinear_activation_params),
            torch.nn.Conv1d(kpnet_hidden_channels, kpnet_hidden_channels, kpnet_conv_size, padding=padding, bias=True),
            getattr(torch.nn, kpnet_nonlinear_activation)(**kpnet_nonlinear_activation_params),
            torch.nn.Dropout(kpnet_dropout),
            torch.nn.Conv1d(kpnet_hidden_channels, kpnet_hidden_channels, kpnet_conv_size, padding=padding, bias=True),
            getattr(torch.nn, kpnet_nonlinear_activation)(**kpnet_nonlinear_activation_params),
            torch.nn.Conv1d(kpnet_hidden_channels, kpnet_hidden_channels, kpnet_conv_size, padding=padding, bias=True),
            getattr(torch.nn, kpnet_nonlinear_activation)(**kpnet_nonlinear_activation_params),
            torch.nn.Dropout(kpnet_dropout),
            torch.nn.Conv1d(kpnet_hidden_channels, kpnet_hidden_channels, kpnet_conv_size, padding=padding, bias=True),
            getattr(torch.nn, kpnet_nonlinear_activation)(**kpnet_nonlinear_activation_params),
            torch.nn.Conv1d(kpnet_hidden_channels, kpnet_hidden_channels, kpnet_conv_size, padding=padding, bias=True),
            getattr(torch.nn, kpnet_nonlinear_activation)(**kpnet_nonlinear_activation_params),
        )

        self.kernel_conv = torch.nn.Conv1d(kpnet_hidden_channels, l_w, kpnet_conv_size,
                                           padding=padding, bias=True)
        self.bias_conv = torch.nn.Conv1d(kpnet_hidden_channels, l_b, kpnet_conv_size, padding=padding,
                                         bias=True)

    def forward(self, c):
        '''
        Args:
            c (Tensor): the conditioning sequence (batch, cond_channels, cond_length)
        Returns:
        '''
        batch, cond_channels, cond_length = c.shape

        c = self.input_conv(c)
        c = c + self.residual_conv(c)
        k = self.kernel_conv(c)
        b = self.bias_conv(c)

        kernels = k.contiguous().view(batch,
                                      self.conv_layers,
                                      self.conv_in_channels,
                                      self.conv_out_channels,
                                      self.conv_kernel_size,
                                      cond_length)
        bias = b.contiguous().view(batch,
                                   self.conv_layers,
                                   self.conv_out_channels,
                                   cond_length)
        return kernels, bias


class LVCBlock(torch.nn.Module):
    ''' the location-variable convolutions
    '''

    def __init__(self,
                 in_channels,
                 cond_channels,
                 upsample_ratio,
                 conv_layers=4,
                 conv_kernel_size=3,
                 cond_hop_length=256,
                 kpnet_hidden_channels=64,
                 kpnet_conv_size=3,
                 kpnet_dropout=0.0
                 ):
        super().__init__()

        self.cond_hop_length = cond_hop_length
        self.conv_layers = conv_layers
        self.conv_kernel_size = conv_kernel_size
        self.convs = torch.nn.ModuleList()

        self.upsample = torch.nn.ConvTranspose1d(in_channels, in_channels,
                                    kernel_size=upsample_ratio*2, stride=upsample_ratio,
                                    padding=upsample_ratio // 2 + upsample_ratio % 2,
                                    output_padding=upsample_ratio % 2)


        self.kernel_predictor = KernelPredictor(
            cond_channels=cond_channels,
            conv_in_channels=in_channels,
            conv_out_channels=2 * in_channels,
            conv_layers=conv_layers,
            conv_kernel_size=conv_kernel_size,
            kpnet_hidden_channels=kpnet_hidden_channels,
            kpnet_conv_size=kpnet_conv_size,
            kpnet_dropout=kpnet_dropout
        )


        for i in range(conv_layers):
            padding = (3 ** i) * int((conv_kernel_size - 1) / 2)
            conv = torch.nn.Conv1d(in_channels, in_channels, kernel_size=conv_kernel_size, padding=padding, dilation=3 ** i)

            self.convs.append(conv)


    def forward(self, x, c):
        ''' forward propagation of the location-variable convolutions.
        Args:
            x (Tensor): the input sequence (batch, in_channels, in_length)
            c (Tensor): the conditioning sequence (batch, cond_channels, cond_length)

        Returns:
            Tensor: the output sequence (batch, in_channels, in_length)
        '''
        batch, in_channels, in_length = x.shape


        kernels, bias = self.kernel_predictor(c)

        x = F.leaky_relu(x, 0.2)
        x = self.upsample(x)

        for i in range(self.conv_layers):
            y = F.leaky_relu(x, 0.2)
            y = self.convs[i](y)
            y = F.leaky_relu(y, 0.2)

            k = kernels[:, i, :, :, :, :]
            b = bias[:, i, :, :]
            y = self.location_variable_convolution(y, k, b, 1, self.cond_hop_length)
            x = x + torch.sigmoid(y[:, :in_channels, :]) * torch.tanh(y[:, in_channels:, :])
        return x

    def location_variable_convolution(self, x, kernel, bias, dilation, hop_size):
        ''' perform location-variable convolution operation on the input sequence (x) using the local convolution kernl.
        Time: 414 μs ± 309 ns per loop (mean ± std. dev. of 7 runs, 1000 loops each), test on NVIDIA V100.
        Args:
            x (Tensor): the input sequence (batch, in_channels, in_length).
            kernel (Tensor): the local convolution kernel (batch, in_channel, out_channels, kernel_size, kernel_length)
            bias (Tensor): the bias for the local convolution (batch, out_channels, kernel_length)
            dilation (int): the dilation of convolution.
            hop_size (int): the hop_size of the conditioning sequence.
        Returns:
            (Tensor): the output sequence after performing local convolution. (batch, out_channels, in_length).
        '''
        batch, in_channels, in_length = x.shape
        batch, in_channels, out_channels, kernel_size, kernel_length = kernel.shape


        assert in_length == (kernel_length * hop_size), "length of (x, kernel) is not matched"

        padding = dilation * int((kernel_size - 1) / 2)
        x = F.pad(x, (padding, padding), 'constant', 0)  # (batch, in_channels, in_length + 2*padding)
        x = x.unfold(2, hop_size + 2 * padding, hop_size)  # (batch, in_channels, kernel_length, hop_size + 2*padding)

        if hop_size < dilation:
            x = F.pad(x, (0, dilation), 'constant', 0)
        x = x.unfold(3, dilation,
                     dilation)  # (batch, in_channels, kernel_length, (hop_size + 2*padding)/dilation, dilation)
        x = x[:, :, :, :, :hop_size]
        x = x.transpose(3, 4)  # (batch, in_channels, kernel_length, dilation, (hop_size + 2*padding)/dilation)
        x = x.unfold(4, kernel_size, 1)  # (batch, in_channels, kernel_length, dilation, _, kernel_size)

        o = torch.einsum('bildsk,biokl->bolsd', x, kernel)
        o = o + bias.unsqueeze(-1).unsqueeze(-1)
        o = o.contiguous().view(batch, out_channels, -1)
        return o