import numpy as np
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import torch
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import torch.nn.functional as F
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from torch import nn
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class EncoderDecoderAttractor(nn.Module):
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def __init__(self, n_units, encoder_dropout=0.1, decoder_dropout=0.1):
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super(EncoderDecoderAttractor, self).__init__()
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self.enc0_dropout = nn.Dropout(encoder_dropout)
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self.encoder = nn.LSTM(n_units, n_units, 1, batch_first=True, dropout=encoder_dropout)
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self.dec0_dropout = nn.Dropout(decoder_dropout)
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self.decoder = nn.LSTM(n_units, n_units, 1, batch_first=True, dropout=decoder_dropout)
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self.counter = nn.Linear(n_units, 1)
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self.n_units = n_units
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def forward_core(self, xs, zeros):
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ilens = torch.from_numpy(np.array([x.shape[0] for x in xs])).to(torch.int64)
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xs = [self.enc0_dropout(x) for x in xs]
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xs = nn.utils.rnn.pad_sequence(xs, batch_first=True, padding_value=-1)
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xs = nn.utils.rnn.pack_padded_sequence(xs, ilens, batch_first=True, enforce_sorted=False)
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_, (hx, cx) = self.encoder(xs)
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zlens = torch.from_numpy(np.array([z.shape[0] for z in zeros])).to(torch.int64)
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max_zlen = torch.max(zlens).to(torch.int).item()
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zeros = [self.enc0_dropout(z) for z in zeros]
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zeros = nn.utils.rnn.pad_sequence(zeros, batch_first=True, padding_value=-1)
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zeros = nn.utils.rnn.pack_padded_sequence(zeros, zlens, batch_first=True, enforce_sorted=False)
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attractors, (_, _) = self.decoder(zeros, (hx, cx))
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attractors = nn.utils.rnn.pad_packed_sequence(attractors, batch_first=True, padding_value=-1,
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total_length=max_zlen)[0]
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attractors = [att[:zlens[i].to(torch.int).item()] for i, att in enumerate(attractors)]
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return attractors
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def forward(self, xs, n_speakers):
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zeros = [torch.zeros(n_spk + 1, self.n_units).to(torch.float32).to(xs[0].device) for n_spk in n_speakers]
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attractors = self.forward_core(xs, zeros)
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labels = torch.cat([torch.from_numpy(np.array([[1] * n_spk + [0]], np.float32)) for n_spk in n_speakers], dim=1)
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labels = labels.to(xs[0].device)
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logit = torch.cat([self.counter(att).view(-1, n_spk + 1) for att, n_spk in zip(attractors, n_speakers)], dim=1)
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loss = F.binary_cross_entropy(torch.sigmoid(logit), labels)
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attractors = [att[slice(0, att.shape[0] - 1)] for att in attractors]
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return loss, attractors
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def estimate(self, xs, max_n_speakers=15):
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zeros = [torch.zeros(max_n_speakers, self.n_units).to(torch.float32).to(xs[0].device) for _ in xs]
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attractors = self.forward_core(xs, zeros)
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probs = [torch.sigmoid(torch.flatten(self.counter(att))) for att in attractors]
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return attractors, probs
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