Beam search implementation in one pass? Dayyyum

This commit is contained in:
James Betker 2021-08-08 23:22:42 -06:00
parent 83ab5e6a00
commit 01cfae28d8

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@ -71,9 +71,9 @@ class GptTts(nn.Module):
return loss_text.mean(), loss_mel.mean(), mel_codes, mel_targets
def inference(self, text_inputs):
b, _ = text_inputs.shape
b, s = text_inputs.shape
text_emb = self.text_embedding(text_inputs)
text_emb = text_emb + self.text_pos_embedding(torch.arange(text_inputs.shape[1], device=text_inputs.device))
text_emb = text_emb + self.text_pos_embedding(torch.arange(s, device=text_inputs.device))
mel_seq = torch.full((b,1), fill_value=self.MEL_START_TOKEN, device=text_emb.device)
stop_encountered = torch.zeros((b,), device=text_emb.device)
@ -98,7 +98,46 @@ class GptTts(nn.Module):
return mel_seq
def inference_beam(self, text_inputs):
pass
beam_width = 16
b, s = text_inputs.shape
assert b == 1 # Beam search only works on batches of one.
text_emb = self.text_embedding(text_inputs)
text_emb = text_emb + self.text_pos_embedding(torch.arange(s, device=text_inputs.device))
mel_seq = torch.full((b,1), fill_value=self.MEL_START_TOKEN, device=text_emb.device)
probabilities = torch.ones((b,), device=text_emb.device)
while len(mel_seq) < self.max_mel_frames:
mel_emb = self.mel_embedding(mel_seq)
mel_emb = mel_emb + self.mel_pos_embedding(torch.arange(mel_emb.shape[1], device=mel_emb.device))
if text_emb.shape[0] != mel_emb.shape[0]:
text_emb = text_emb.repeat(mel_emb.shape[0], 1, 1)
emb = torch.cat([text_emb, mel_emb], dim=1)
enc = self.gpt(emb)
mel_logits = self.final_norm(enc[:, text_emb.shape[1]:])
mel_logits = self.mel_head(mel_logits)
topk = torch.topk(F.softmax(mel_logits[:, -1], dim=-1), dim=-1, k=beam_width)
probabilities = (probabilities.repeat_interleave(beam_width, dim=0) * topk.values.flatten())
probabilities, sort_indices = torch.sort(probabilities, descending=True)
probabilities = probabilities[:beam_width]
mel_seq = mel_seq.repeat_interleave(beam_width, dim=0)
codes = topk.indices.flatten()
mel_seq = torch.cat([mel_seq, codes.unsqueeze(1)], dim=1)
mel_seq = mel_seq[sort_indices]
mel_seq = mel_seq[:beam_width]
if torch.all(torch.any(mel_seq == self.MEL_STOP_TOKEN, dim=1)):
break
if mel_seq.shape[1] >= self.max_mel_frames:
print("Warning! Encountered frame limit before a stop token. Output is likely wrong.")
# Format mel_seq so that the DVAE can actually use it (it is a two-tiered DVAE)
mel_seq = mel_seq[0, 1:-1].unsqueeze(0) # Pick most likely outcome, remove first and last tokens, which were artificially added for GPT
mel_seq = mel_seq * (mel_seq < 512) # The DVAE doesn't understand BOS/EOS/PAD tokens.
return mel_seq
@register_model