from contextlib import contextmanager
from typing import Dict, List, Optional, Tuple, Union
import torch
from packaging.version import parse as V
from typeguard import typechecked
from espnet2.asr.ctc import CTC
from espnet2.asr.decoder.abs_decoder import AbsDecoder
from espnet2.asr.encoder.abs_encoder import AbsEncoder
from espnet2.asr.frontend.abs_frontend import AbsFrontend
from espnet2.asr.postencoder.abs_postencoder import AbsPostEncoder
from espnet2.asr.preencoder.abs_preencoder import AbsPreEncoder
from espnet2.asr.specaug.abs_specaug import AbsSpecAug
from espnet2.mt.espnet_model import ESPnetMTModel
from espnet2.torch_utils.device_funcs import force_gatherable
from espnet.nets.e2e_asr_common import ErrorCalculator as ASRErrorCalculator
from espnet.nets.pytorch_backend.nets_utils import th_accuracy
from espnet.nets.pytorch_backend.transformer.add_sos_eos import add_sos_eos
if V(torch.__version__) >= V("1.6.0"):
from torch.cuda.amp import autocast
else:
# Nothing to do if torch<1.6.0
@contextmanager
def autocast(enabled=True):
yield
[docs]class ESPnetDiscreteASRModel(ESPnetMTModel):
"""Encoder-Decoder model"""
@typechecked
def __init__(
self,
vocab_size: int,
token_list: Union[Tuple[str, ...], List[str]],
frontend: Optional[AbsFrontend],
specaug: Optional[AbsSpecAug],
preencoder: Optional[AbsPreEncoder],
encoder: AbsEncoder,
postencoder: Optional[AbsPostEncoder],
decoder: AbsDecoder,
ctc: Optional[CTC],
ctc_weight: float = 0.5,
interctc_weight: float = 0.0,
src_vocab_size: int = 0,
src_token_list: Union[Tuple[str, ...], List[str]] = [],
ignore_id: int = -1,
lsm_weight: float = 0.0,
length_normalized_loss: bool = False,
report_bleu: bool = True,
sym_space: str = "<space>",
sym_blank: str = "<blank>",
extract_feats_in_collect_stats: bool = True,
share_decoder_input_output_embed: bool = False,
share_encoder_decoder_input_embed: bool = False,
):
assert 0.0 <= ctc_weight <= 1.0, ctc_weight
super().__init__(
vocab_size=vocab_size,
token_list=token_list,
frontend=frontend,
preencoder=preencoder,
encoder=encoder,
postencoder=postencoder,
decoder=decoder,
src_vocab_size=src_vocab_size,
src_token_list=src_token_list,
ignore_id=ignore_id,
lsm_weight=lsm_weight,
length_normalized_loss=length_normalized_loss,
report_bleu=report_bleu,
sym_space=sym_space,
sym_blank=sym_blank,
extract_feats_in_collect_stats=extract_feats_in_collect_stats,
share_decoder_input_output_embed=share_decoder_input_output_embed,
share_encoder_decoder_input_embed=share_encoder_decoder_input_embed,
)
self.specaug = specaug
# note that eos is the same as sos (equivalent ID)
self.blank_id = 0
self.ctc_weight = ctc_weight
self.interctc_weight = interctc_weight
if ctc_weight == 0.0:
self.ctc = None
else:
self.ctc = ctc
if report_bleu:
self.error_calculator = ASRErrorCalculator(
token_list, sym_space, sym_blank, True, True
)
if not hasattr(self.encoder, "interctc_use_conditioning"):
self.encoder.interctc_use_conditioning = False
if self.encoder.interctc_use_conditioning:
self.encoder.conditioning_layer = torch.nn.Linear(
vocab_size, self.encoder.output_size()
)
[docs] def forward(
self,
text: torch.Tensor,
text_lengths: torch.Tensor,
src_text: torch.Tensor,
src_text_lengths: torch.Tensor,
**kwargs,
) -> Tuple[torch.Tensor, Dict[str, torch.Tensor], torch.Tensor]:
"""Frontend + Encoder + Decoder + Calc loss
Args:
text: (Batch, Length)
text_lengths: (Batch,)
src_text: (Batch, length)
src_text_lengths: (Batch,)
kwargs: "utt_id" is among the input.
"""
assert text_lengths.dim() == 1, text_lengths.shape
# Check that batch_size is unified
assert (
text.shape[0]
== text_lengths.shape[0]
== src_text.shape[0]
== src_text_lengths.shape[0]
), (text.shape, text_lengths.shape, src_text.shape, src_text_lengths.shape)
batch_size = src_text.shape[0]
# for data-parallel
text = text[:, : text_lengths.max()]
src_text = src_text[:, : src_text_lengths.max()]
# 1. Encoder
encoder_out, encoder_out_lens = self.encode(src_text, src_text_lengths)
intermediate_outs = None
if isinstance(encoder_out, tuple):
intermediate_outs = encoder_out[1]
encoder_out = encoder_out[0]
loss_ctc, cer_ctc = None, None
stats = dict()
# 1. CTC branch
if self.ctc_weight != 0.0:
loss_ctc, cer_ctc = self._calc_ctc_loss(
encoder_out, encoder_out_lens, text, text_lengths
)
# Collect CTC branch stats
stats["loss_ctc"] = loss_ctc.detach() if loss_ctc is not None else None
stats["cer_ctc"] = cer_ctc
# Intermediate CTC (optional)
loss_interctc = 0.0
if self.interctc_weight != 0.0 and intermediate_outs is not None:
for layer_idx, intermediate_out in intermediate_outs:
# we assume intermediate_out has the same length & padding
# as those of encoder_out
loss_ic, cer_ic = self._calc_ctc_loss(
intermediate_out, encoder_out_lens, text, text_lengths
)
loss_interctc = loss_interctc + loss_ic
# Collect Intermedaite CTC stats
stats["loss_interctc_layer{}".format(layer_idx)] = (
loss_ic.detach() if loss_ic is not None else None
)
stats["cer_interctc_layer{}".format(layer_idx)] = cer_ic
loss_interctc = loss_interctc / len(intermediate_outs)
# calculate whole encoder loss
loss_ctc = (
1 - self.interctc_weight
) * loss_ctc + self.interctc_weight * loss_interctc
# 2a. Attention-decoder branch (MT)
loss_att, acc_att, cer_att, wer_att = self._calc_att_loss(
encoder_out, encoder_out_lens, text, text_lengths
)
# 3. Loss computation
if self.ctc_weight > 0.0:
loss = self.ctc_weight * loss_ctc + (1 - self.ctc_weight) * loss_att
else:
loss = loss_att
stats["loss_att"] = loss_att.detach() if loss_att is not None else None
stats["acc"] = acc_att
stats["cer"] = cer_att
stats["wer"] = wer_att
stats["loss"] = loss.detach()
# force_gatherable: to-device and to-tensor if scalar for DataParallel
loss, stats, weight = force_gatherable((loss, stats, batch_size), loss.device)
return loss, stats, weight
[docs] def encode(
self, src_text: torch.Tensor, src_text_lengths: torch.Tensor
) -> Tuple[torch.Tensor, torch.Tensor]:
"""Frontend + Encoder. Note that this method is used by mt_inference.py
Args:
src_text: (Batch, Length, ...)
src_text_lengths: (Batch, )
"""
with autocast(False):
# 1. Extract feats
feats, feats_lengths = self._extract_feats(src_text, src_text_lengths)
# 2. Data augmentation
if self.specaug is not None and self.training:
feats, feats_lengths = self.specaug(feats, feats_lengths)
# Pre-encoder, e.g. used for raw input data
if self.preencoder is not None:
feats, feats_lengths = self.preencoder(feats, feats_lengths)
# 4. Forward encoder
# feats: (Batch, Length, Dim)
# -> encoder_out: (Batch, Length2, Dim2)
# encoder_out, encoder_out_lens, _ = self.encoder(feats, feats_lengths)
if self.encoder.interctc_use_conditioning:
encoder_out, encoder_out_lens, _ = self.encoder(
feats, feats_lengths, ctc=self.ctc
)
else:
encoder_out, encoder_out_lens, _ = self.encoder(feats, feats_lengths)
intermediate_outs = None
if isinstance(encoder_out, tuple):
intermediate_outs = encoder_out[1]
encoder_out = encoder_out[0]
# Post-encoder, e.g. NLU
if self.postencoder is not None:
encoder_out, encoder_out_lens = self.postencoder(
encoder_out, encoder_out_lens
)
assert encoder_out.size(0) == src_text.size(0), (
encoder_out.size(),
src_text.size(0),
)
assert encoder_out.size(1) <= encoder_out_lens.max(), (
encoder_out.size(),
encoder_out_lens.max(),
)
if intermediate_outs is not None:
return (encoder_out, intermediate_outs), encoder_out_lens
return encoder_out, encoder_out_lens
def _calc_att_loss(
self,
encoder_out: torch.Tensor,
encoder_out_lens: torch.Tensor,
ys_pad: torch.Tensor,
ys_pad_lens: torch.Tensor,
):
ys_in_pad, ys_out_pad = add_sos_eos(ys_pad, self.sos, self.eos, self.ignore_id)
ys_in_lens = ys_pad_lens + 1
# 1. Forward decoder
decoder_out, _ = self.decoder(
encoder_out, encoder_out_lens, ys_in_pad, ys_in_lens
)
# 2. Compute attention loss
loss_att = self.criterion_mt(decoder_out, ys_out_pad)
acc_att = th_accuracy(
decoder_out.view(-1, self.vocab_size),
ys_out_pad,
ignore_label=self.ignore_id,
)
# Compute cer/wer using attention-decoder
if self.training or self.error_calculator is None:
cer_att, wer_att = None, None
else:
ys_hat = decoder_out.argmax(dim=-1)
cer_att, wer_att = self.error_calculator(ys_hat.cpu(), ys_pad.cpu())
return loss_att, acc_att, cer_att, wer_att
def _calc_ctc_loss(
self,
encoder_out: torch.Tensor,
encoder_out_lens: torch.Tensor,
ys_pad: torch.Tensor,
ys_pad_lens: torch.Tensor,
):
# Calc CTC loss
loss_ctc = self.ctc(encoder_out, encoder_out_lens, ys_pad, ys_pad_lens)
# Calc CER using CTC
cer_ctc = None
if not self.training and self.error_calculator is not None:
ys_hat = self.ctc.argmax(encoder_out).data
cer_ctc = self.error_calculator(ys_hat.cpu(), ys_pad.cpu(), is_ctc=True)
return loss_ctc, cer_ctc