FunASR/funasr/models/ct_transformer/model.py
2023-12-21 14:20:21 +08:00

212 lines
7.4 KiB
Python

from typing import Any
from typing import List
from typing import Tuple
import torch
import torch.nn as nn
from funasr.register import tables
@tables.register("model_classes", "CTTransformer")
class CTTransformer(nn.Module):
"""
Author: Speech Lab of DAMO Academy, Alibaba Group
CT-Transformer: Controllable time-delay transformer for real-time punctuation prediction and disfluency detection
https://arxiv.org/pdf/2003.01309.pdf
"""
def __init__(
self,
encoder: str = None,
encoder_conf: str = None,
vocab_size: int = -1,
punc_list: list = None,
punc_weight: list = None,
embed_unit: int = 128,
att_unit: int = 256,
dropout_rate: float = 0.5,
ignore_id: int = -1,
sos: int = 1,
eos: int = 2,
**kwargs,
):
super().__init__()
punc_size = len(punc_list)
if punc_weight is None:
punc_weight = [1] * punc_size
self.embed = nn.Embedding(vocab_size, embed_unit)
encoder_class = tables.encoder_classes.get(encoder.lower())
encoder = encoder_class(**encoder_conf)
self.decoder = nn.Linear(att_unit, punc_size)
self.encoder = encoder
self.punc_list = punc_list
self.punc_weight = punc_weight
self.ignore_id = ignore_id
self.sos = sos
self.eos = eos
def punc_forward(self, input: torch.Tensor, text_lengths: torch.Tensor) -> Tuple[torch.Tensor, None]:
"""Compute loss value from buffer sequences.
Args:
input (torch.Tensor): Input ids. (batch, len)
hidden (torch.Tensor): Target ids. (batch, len)
"""
x = self.embed(input)
# mask = self._target_mask(input)
h, _, _ = self.encoder(x, text_lengths)
y = self.decoder(h)
return y, None
def with_vad(self):
return False
def score(self, y: torch.Tensor, state: Any, x: torch.Tensor) -> Tuple[torch.Tensor, Any]:
"""Score new token.
Args:
y (torch.Tensor): 1D torch.int64 prefix tokens.
state: Scorer state for prefix tokens
x (torch.Tensor): encoder feature that generates ys.
Returns:
tuple[torch.Tensor, Any]: Tuple of
torch.float32 scores for next token (vocab_size)
and next state for ys
"""
y = y.unsqueeze(0)
h, _, cache = self.encoder.forward_one_step(self.embed(y), self._target_mask(y), cache=state)
h = self.decoder(h[:, -1])
logp = h.log_softmax(dim=-1).squeeze(0)
return logp, cache
def batch_score(self, ys: torch.Tensor, states: List[Any], xs: torch.Tensor) -> Tuple[torch.Tensor, List[Any]]:
"""Score new token batch.
Args:
ys (torch.Tensor): torch.int64 prefix tokens (n_batch, ylen).
states (List[Any]): Scorer states for prefix tokens.
xs (torch.Tensor):
The encoder feature that generates ys (n_batch, xlen, n_feat).
Returns:
tuple[torch.Tensor, List[Any]]: Tuple of
batchfied scores for next token with shape of `(n_batch, vocab_size)`
and next state list for ys.
"""
# merge states
n_batch = len(ys)
n_layers = len(self.encoder.encoders)
if states[0] is None:
batch_state = None
else:
# transpose state of [batch, layer] into [layer, batch]
batch_state = [torch.stack([states[b][i] for b in range(n_batch)]) for i in range(n_layers)]
# batch decoding
h, _, states = self.encoder.forward_one_step(self.embed(ys), self._target_mask(ys), cache=batch_state)
h = self.decoder(h[:, -1])
logp = h.log_softmax(dim=-1)
# transpose state of [layer, batch] into [batch, layer]
state_list = [[states[i][b] for i in range(n_layers)] for b in range(n_batch)]
return logp, state_list
def nll(
self,
text: torch.Tensor,
punc: torch.Tensor,
text_lengths: torch.Tensor,
punc_lengths: torch.Tensor,
max_length: Optional[int] = None,
vad_indexes: Optional[torch.Tensor] = None,
vad_indexes_lengths: Optional[torch.Tensor] = None,
) -> Tuple[torch.Tensor, torch.Tensor]:
"""Compute negative log likelihood(nll)
Normally, this function is called in batchify_nll.
Args:
text: (Batch, Length)
punc: (Batch, Length)
text_lengths: (Batch,)
max_lengths: int
"""
batch_size = text.size(0)
# For data parallel
if max_length is None:
text = text[:, :text_lengths.max()]
punc = punc[:, :text_lengths.max()]
else:
text = text[:, :max_length]
punc = punc[:, :max_length]
if self.with_vad():
# Should be VadRealtimeTransformer
assert vad_indexes is not None
y, _ = self.punc_forward(text, text_lengths, vad_indexes)
else:
# Should be TargetDelayTransformer,
y, _ = self.punc_forward(text, text_lengths)
# Calc negative log likelihood
# nll: (BxL,)
if self.training == False:
_, indices = y.view(-1, y.shape[-1]).topk(1, dim=1)
from sklearn.metrics import f1_score
f1_score = f1_score(punc.view(-1).detach().cpu().numpy(),
indices.squeeze(-1).detach().cpu().numpy(),
average='micro')
nll = torch.Tensor([f1_score]).repeat(text_lengths.sum())
return nll, text_lengths
else:
self.punc_weight = self.punc_weight.to(punc.device)
nll = F.cross_entropy(y.view(-1, y.shape[-1]), punc.view(-1), self.punc_weight, reduction="none",
ignore_index=self.ignore_id)
# nll: (BxL,) -> (BxL,)
if max_length is None:
nll.masked_fill_(make_pad_mask(text_lengths).to(nll.device).view(-1), 0.0)
else:
nll.masked_fill_(
make_pad_mask(text_lengths, maxlen=max_length + 1).to(nll.device).view(-1),
0.0,
)
# nll: (BxL,) -> (B, L)
nll = nll.view(batch_size, -1)
return nll, text_lengths
def forward(
self,
text: torch.Tensor,
punc: torch.Tensor,
text_lengths: torch.Tensor,
punc_lengths: torch.Tensor,
vad_indexes: Optional[torch.Tensor] = None,
vad_indexes_lengths: Optional[torch.Tensor] = None,
) -> Tuple[torch.Tensor, Dict[str, torch.Tensor], torch.Tensor]:
nll, y_lengths = self.nll(text, punc, text_lengths, punc_lengths, vad_indexes=vad_indexes)
ntokens = y_lengths.sum()
loss = nll.sum() / ntokens
stats = dict(loss=loss.detach())
# force_gatherable: to-device and to-tensor if scalar for DataParallel
loss, stats, weight = force_gatherable((loss, stats, ntokens), loss.device)
return loss, stats, weight
def generate(self,
text: torch.Tensor,
text_lengths: torch.Tensor,
vad_indexes: Optional[torch.Tensor] = None) -> Tuple[torch.Tensor, None]:
if self.with_vad():
assert vad_indexes is not None
return self.punc_forward(text, text_lengths, vad_indexes)
else:
return self.punc_forward(text, text_lengths)