replace by references in confermer_ctc

This commit is contained in:
sathvik udupa 2023-05-01 17:58:46 +05:30
parent b2555fb249
commit 99487d3000
12 changed files with 86 additions and 3292 deletions

View File

@ -0,0 +1,75 @@
## Introduction
Please visit
<https://icefall.readthedocs.io/en/latest/recipes/librispeech/conformer_ctc.html>
for how to run this recipe.
## How to compute framewise alignment information
### Step 1: Train a model
Please use `conformer_ctc/train.py` to train a model.
See <https://icefall.readthedocs.io/en/latest/recipes/librispeech/conformer_ctc.html>
for how to do it.
### Step 2: Compute framewise alignment
Run
```
# Choose a checkpoint and determine the number of checkpoints to average
epoch=30
avg=15
./conformer_ctc/ali.py \
--epoch $epoch \
--avg $avg \
--max-duration 500 \
--bucketing-sampler 0 \
--full-libri 1 \
--exp-dir conformer_ctc/exp \
--lang-dir data/lang_bpe_500 \
--ali-dir data/ali_500
```
and you will get four files inside the folder `data/ali_500`:
```
$ ls -lh data/ali_500
total 546M
-rw-r--r-- 1 kuangfangjun root 1.1M Sep 28 08:06 test_clean.pt
-rw-r--r-- 1 kuangfangjun root 1.1M Sep 28 08:07 test_other.pt
-rw-r--r-- 1 kuangfangjun root 542M Sep 28 11:36 train-960.pt
-rw-r--r-- 1 kuangfangjun root 2.1M Sep 28 11:38 valid.pt
```
**Note**: It can take more than 3 hours to compute the alignment
for the training dataset, which contains 960 * 3 = 2880 hours of data.
**Caution**: The model parameters in `conformer_ctc/ali.py` have to match those
in `conformer_ctc/train.py`.
**Caution**: You have to set the parameter `preserve_id` to `True` for `CutMix`.
Search `./conformer_ctc/asr_datamodule.py` for `preserve_id`.
### Step 3: Check your extracted alignments
There is a file `test_ali.py` in `icefall/test` that can be used to test your
alignments. It uses pre-computed alignments to modify a randomly generated
`nnet_output` and it checks that we can decode the correct transcripts
from the resulting `nnet_output`.
You should get something like the following if you run that script:
```
$ ./test/test_ali.py
['THE GOOD NATURED AUDIENCE IN PITY TO FALLEN MAJESTY SHOWED FOR ONCE GREATER DEFERENCE TO THE KING THAN TO THE MINISTER AND SUNG THE PSALM WHICH THE FORMER HAD CALLED FOR', 'THE OLD SERVANT TOLD HIM QUIETLY AS THEY CREPT BACK TO DWELL THAT THIS PASSAGE THAT LED FROM THE HUT IN THE PLEASANCE TO SHERWOOD AND THAT GEOFFREY FOR THE TIME WAS HIDING WITH THE OUTLAWS IN THE FOREST', 'FOR A WHILE SHE LAY IN HER CHAIR IN HAPPY DREAMY PLEASURE AT SUN AND BIRD AND TREE', "BUT THE ESSENCE OF LUTHER'S LECTURES IS THERE"]
['THE GOOD NATURED AUDIENCE IN PITY TO FALLEN MAJESTY SHOWED FOR ONCE GREATER DEFERENCE TO THE KING THAN TO THE MINISTER AND SUNG THE PSALM WHICH THE FORMER HAD CALLED FOR', 'THE OLD SERVANT TOLD HIM QUIETLY AS THEY CREPT BACK TO GAMEWELL THAT THIS PASSAGE WAY LED FROM THE HUT IN THE PLEASANCE TO SHERWOOD AND THAT GEOFFREY FOR THE TIME WAS HIDING WITH THE OUTLAWS IN THE FOREST', 'FOR A WHILE SHE LAY IN HER CHAIR IN HAPPY DREAMY PLEASURE AT SUN AND BIRD AND TREE', "BUT THE ESSENCE OF LUTHER'S LECTURES IS THERE"]
```
### Step 4: Use your alignments in training
Please refer to `conformer_mmi/train.py` for usage. Some useful
functions are:
- `load_alignments()`, it loads alignment saved by `conformer_ctc/ali.py`
- `convert_alignments_to_tensor()`, it converts alignments to PyTorch tensors
- `lookup_alignments()`, it returns the alignments of utterances by giving the cut ID of the utterances.

View File

@ -0,0 +1 @@
../../../librispeech/ASR/conformer_ctc/__init__.py

View File

@ -1,395 +0,0 @@
#!/usr/bin/env python3
# Copyright 2021 Xiaomi Corp. (authors: Fangjun Kuang)
#
# See ../../../../LICENSE for clarification regarding multiple authors
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""
Usage:
./conformer_ctc/ali.py \
--exp-dir ./conformer_ctc/exp \
--lang-dir ./data/lang_bpe_500 \
--epoch 20 \
--avg 10 \
--max-duration 300 \
--dataset train-clean-100 \
--out-dir data/ali
"""
import argparse
import logging
from pathlib import Path
import k2
import numpy as np
import torch
from asr_datamodule import LibriSpeechAsrDataModule
from conformer import Conformer
from lhotse import CutSet
from lhotse.features.io import FeaturesWriter, NumpyHdf5Writer
from icefall.bpe_graph_compiler import BpeCtcTrainingGraphCompiler
from icefall.checkpoint import average_checkpoints, load_checkpoint
from icefall.decode import one_best_decoding
from icefall.env import get_env_info
from icefall.lexicon import Lexicon
from icefall.utils import (
AttributeDict,
encode_supervisions,
get_alignments,
setup_logger,
)
def get_parser():
parser = argparse.ArgumentParser(
formatter_class=argparse.ArgumentDefaultsHelpFormatter
)
parser.add_argument(
"--epoch",
type=int,
default=34,
help="It specifies the checkpoint to use for decoding."
"Note: Epoch counts from 0.",
)
parser.add_argument(
"--avg",
type=int,
default=20,
help="Number of checkpoints to average. Automatically select "
"consecutive checkpoints before the checkpoint specified by "
"'--epoch'. ",
)
parser.add_argument(
"--lang-dir",
type=str,
default="data/lang_bpe_500",
help="The lang dir",
)
parser.add_argument(
"--exp-dir",
type=str,
default="conformer_ctc/exp",
help="The experiment dir",
)
parser.add_argument(
"--out-dir",
type=str,
required=True,
help="""Output directory.
It contains 3 generated files:
- labels_xxx.h5
- aux_labels_xxx.h5
- librispeech_cuts_xxx.jsonl.gz
where xxx is the value of `--dataset`. For instance, if
`--dataset` is `train-clean-100`, it will contain 3 files:
- `labels_train-clean-100.h5`
- `aux_labels_train-clean-100.h5`
- `librispeech_cuts_train-clean-100.jsonl.gz`
Note: Both labels_xxx.h5 and aux_labels_xxx.h5 contain framewise
alignment. The difference is that labels_xxx.h5 contains repeats.
""",
)
parser.add_argument(
"--dataset",
type=str,
required=True,
help="""The name of the dataset to compute alignments for.
Possible values are:
- test-clean.
- test-other
- train-clean-100
- train-clean-360
- train-other-500
- dev-clean
- dev-other
""",
)
return parser
def get_params() -> AttributeDict:
params = AttributeDict(
{
"lm_dir": Path("data/lm"),
"feature_dim": 80,
"nhead": 8,
"attention_dim": 512,
"subsampling_factor": 4,
# Set it to 0 since attention decoder
# is not used for computing alignments
"num_decoder_layers": 0,
"vgg_frontend": False,
"use_feat_batchnorm": True,
"output_beam": 10,
"use_double_scores": True,
"env_info": get_env_info(),
}
)
return params
def compute_alignments(
model: torch.nn.Module,
dl: torch.utils.data.DataLoader,
labels_writer: FeaturesWriter,
aux_labels_writer: FeaturesWriter,
params: AttributeDict,
graph_compiler: BpeCtcTrainingGraphCompiler,
) -> CutSet:
"""Compute the framewise alignments of a dataset.
Args:
model:
The neural network model.
dl:
Dataloader containing the dataset.
params:
Parameters for computing alignments.
graph_compiler:
It converts token IDs to decoding graphs.
Returns:
Return a CutSet. Each cut has two custom fields: labels_alignment
and aux_labels_alignment, containing framewise alignments information.
Both are of type `lhotse.array.TemporalArray`. The difference between
the two alignments is that `labels_alignment` contain repeats.
"""
try:
num_batches = len(dl)
except TypeError:
num_batches = "?"
num_cuts = 0
device = graph_compiler.device
cuts = []
for batch_idx, batch in enumerate(dl):
feature = batch["inputs"]
# at entry, feature is [N, T, C]
assert feature.ndim == 3
feature = feature.to(device)
supervisions = batch["supervisions"]
cut_list = supervisions["cut"]
for cut in cut_list:
assert len(cut.supervisions) == 1, f"{len(cut.supervisions)}"
nnet_output, encoder_memory, memory_mask = model(feature, supervisions)
# nnet_output is [N, T, C]
supervision_segments, texts = encode_supervisions(
supervisions, subsampling_factor=params.subsampling_factor
)
# we need also to sort cut_ids as encode_supervisions()
# reorders "texts".
# In general, new2old is an identity map since lhotse sorts the returned
# cuts by duration in descending order
new2old = supervision_segments[:, 0].tolist()
cut_list = [cut_list[i] for i in new2old]
token_ids = graph_compiler.texts_to_ids(texts)
decoding_graph = graph_compiler.compile(token_ids)
dense_fsa_vec = k2.DenseFsaVec(
nnet_output,
supervision_segments,
allow_truncate=params.subsampling_factor - 1,
)
lattice = k2.intersect_dense(
decoding_graph,
dense_fsa_vec,
params.output_beam,
)
best_path = one_best_decoding(
lattice=lattice,
use_double_scores=params.use_double_scores,
)
labels_ali = get_alignments(best_path, kind="labels")
aux_labels_ali = get_alignments(best_path, kind="aux_labels")
assert len(labels_ali) == len(aux_labels_ali) == len(cut_list)
for cut, labels, aux_labels in zip(cut_list, labels_ali, aux_labels_ali):
cut.labels_alignment = labels_writer.store_array(
key=cut.id,
value=np.asarray(labels, dtype=np.int32),
# frame shift is 0.01s, subsampling_factor is 4
frame_shift=0.04,
temporal_dim=0,
start=0,
)
cut.aux_labels_alignment = aux_labels_writer.store_array(
key=cut.id,
value=np.asarray(aux_labels, dtype=np.int32),
# frame shift is 0.01s, subsampling_factor is 4
frame_shift=0.04,
temporal_dim=0,
start=0,
)
cuts += cut_list
num_cuts += len(cut_list)
if batch_idx % 100 == 0:
batch_str = f"{batch_idx}/{num_batches}"
logging.info(f"batch {batch_str}, cuts processed until now is {num_cuts}")
return CutSet.from_cuts(cuts)
@torch.no_grad()
def main():
parser = get_parser()
LibriSpeechAsrDataModule.add_arguments(parser)
args = parser.parse_args()
args.enable_spec_aug = False
args.enable_musan = False
args.return_cuts = True
args.concatenate_cuts = False
params = get_params()
params.update(vars(args))
setup_logger(f"{params.exp_dir}/log-ali")
logging.info(f"Computing alignments for {params.dataset} - started")
logging.info(params)
out_dir = Path(params.out_dir)
out_dir.mkdir(exist_ok=True)
out_labels_ali_filename = out_dir / f"labels_{params.dataset}.h5"
out_aux_labels_ali_filename = out_dir / f"aux_labels_{params.dataset}.h5"
out_manifest_filename = out_dir / f"librispeech_cuts_{params.dataset}.jsonl.gz"
for f in (
out_labels_ali_filename,
out_aux_labels_ali_filename,
out_manifest_filename,
):
if f.exists():
logging.info(f"{f} exists - skipping")
return
lexicon = Lexicon(params.lang_dir)
max_token_id = max(lexicon.tokens)
num_classes = max_token_id + 1 # +1 for the blank
device = torch.device("cpu")
if torch.cuda.is_available():
device = torch.device("cuda", 0)
logging.info(f"device: {device}")
graph_compiler = BpeCtcTrainingGraphCompiler(
params.lang_dir,
device=device,
sos_token="<sos/eos>",
eos_token="<sos/eos>",
)
logging.info("About to create model")
model = Conformer(
num_features=params.feature_dim,
nhead=params.nhead,
d_model=params.attention_dim,
num_classes=num_classes,
subsampling_factor=params.subsampling_factor,
num_decoder_layers=params.num_decoder_layers,
vgg_frontend=params.vgg_frontend,
use_feat_batchnorm=params.use_feat_batchnorm,
)
model.to(device)
if params.avg == 1:
load_checkpoint(
f"{params.exp_dir}/epoch-{params.epoch}.pt", model, strict=False
)
else:
start = params.epoch - params.avg + 1
filenames = []
for i in range(start, params.epoch + 1):
if start >= 0:
filenames.append(f"{params.exp_dir}/epoch-{i}.pt")
logging.info(f"averaging {filenames}")
model.load_state_dict(
average_checkpoints(filenames, device=device), strict=False
)
model.eval()
librispeech = LibriSpeechAsrDataModule(args)
if params.dataset == "test-clean":
test_clean_cuts = librispeech.test_clean_cuts()
dl = librispeech.test_dataloaders(test_clean_cuts)
elif params.dataset == "test-other":
test_other_cuts = librispeech.test_other_cuts()
dl = librispeech.test_dataloaders(test_other_cuts)
elif params.dataset == "train-clean-100":
train_clean_100_cuts = librispeech.train_clean_100_cuts()
dl = librispeech.train_dataloaders(train_clean_100_cuts)
elif params.dataset == "train-clean-360":
train_clean_360_cuts = librispeech.train_clean_360_cuts()
dl = librispeech.train_dataloaders(train_clean_360_cuts)
elif params.dataset == "train-other-500":
train_other_500_cuts = librispeech.train_other_500_cuts()
dl = librispeech.train_dataloaders(train_other_500_cuts)
elif params.dataset == "dev-clean":
dev_clean_cuts = librispeech.dev_clean_cuts()
dl = librispeech.valid_dataloaders(dev_clean_cuts)
else:
assert params.dataset == "dev-other", f"{params.dataset}"
dev_other_cuts = librispeech.dev_other_cuts()
dl = librispeech.valid_dataloaders(dev_other_cuts)
logging.info(f"Processing {params.dataset}")
with NumpyHdf5Writer(out_labels_ali_filename) as labels_writer:
with NumpyHdf5Writer(out_aux_labels_ali_filename) as aux_labels_writer:
cut_set = compute_alignments(
model=model,
dl=dl,
labels_writer=labels_writer,
aux_labels_writer=aux_labels_writer,
params=params,
graph_compiler=graph_compiler,
)
cut_set.to_file(out_manifest_filename)
logging.info(
f"For dataset {params.dataset}, its alignments with repeats are "
f"saved to {out_labels_ali_filename}, the alignments without repeats "
f"are saved to {out_aux_labels_ali_filename}, and the cut manifest "
f"file is {out_manifest_filename}. Number of cuts: {len(cut_set)}"
)
torch.set_num_threads(1)
torch.set_num_interop_threads(1)
if __name__ == "__main__":
main()

View File

@ -0,0 +1 @@
../../../librispeech/ASR/conformer_ctc/ali.py

View File

@ -1,910 +0,0 @@
#!/usr/bin/env python3
# Copyright (c) 2021 University of Chinese Academy of Sciences (author: Han Zhu)
#
# See ../../../../LICENSE for clarification regarding multiple authors
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import math
import warnings
from typing import Optional, Tuple, Union
import torch
from torch import Tensor, nn
from transformer import Supervisions, Transformer, encoder_padding_mask
class Conformer(Transformer):
"""
Args:
num_features (int): Number of input features
num_classes (int): Number of output classes
subsampling_factor (int): subsampling factor of encoder (the convolution layers before transformers)
d_model (int): attention dimension
nhead (int): number of head
dim_feedforward (int): feedforward dimention
num_encoder_layers (int): number of encoder layers
num_decoder_layers (int): number of decoder layers
dropout (float): dropout rate
cnn_module_kernel (int): Kernel size of convolution module
normalize_before (bool): whether to use layer_norm before the first block.
vgg_frontend (bool): whether to use vgg frontend.
"""
def __init__(
self,
num_features: int,
num_classes: int,
subsampling_factor: int = 4,
d_model: int = 256,
nhead: int = 4,
dim_feedforward: int = 2048,
num_encoder_layers: int = 12,
num_decoder_layers: int = 6,
dropout: float = 0.1,
cnn_module_kernel: int = 31,
normalize_before: bool = True,
vgg_frontend: bool = False,
use_feat_batchnorm: Union[float, bool] = 0.1,
) -> None:
super(Conformer, self).__init__(
num_features=num_features,
num_classes=num_classes,
subsampling_factor=subsampling_factor,
d_model=d_model,
nhead=nhead,
dim_feedforward=dim_feedforward,
num_encoder_layers=num_encoder_layers,
num_decoder_layers=num_decoder_layers,
dropout=dropout,
normalize_before=normalize_before,
vgg_frontend=vgg_frontend,
use_feat_batchnorm=use_feat_batchnorm,
)
self.encoder_pos = RelPositionalEncoding(d_model, dropout)
use_conv_batchnorm = True
if isinstance(use_feat_batchnorm, float):
use_conv_batchnorm = False
encoder_layer = ConformerEncoderLayer(
d_model,
nhead,
dim_feedforward,
dropout,
cnn_module_kernel,
normalize_before,
use_conv_batchnorm,
)
self.encoder = ConformerEncoder(encoder_layer, num_encoder_layers)
self.normalize_before = normalize_before
if self.normalize_before:
self.after_norm = nn.LayerNorm(d_model)
else:
# Note: TorchScript detects that self.after_norm could be used inside forward()
# and throws an error without this change.
self.after_norm = identity
def run_encoder(
self, x: Tensor, supervisions: Optional[Supervisions] = None
) -> Tuple[Tensor, Optional[Tensor]]:
"""
Args:
x:
The model input. Its shape is (N, T, C).
supervisions:
Supervision in lhotse format.
See https://github.com/lhotse-speech/lhotse/blob/master/lhotse/dataset/speech_recognition.py#L32 # noqa
CAUTION: It contains length information, i.e., start and number of
frames, before subsampling
It is read directly from the batch, without any sorting. It is used
to compute encoder padding mask, which is used as memory key padding
mask for the decoder.
Returns:
Tensor: Predictor tensor of dimension (input_length, batch_size, d_model).
Tensor: Mask tensor of dimension (batch_size, input_length)
"""
x = self.encoder_embed(x)
x, pos_emb = self.encoder_pos(x)
x = x.permute(1, 0, 2) # (B, T, F) -> (T, B, F)
mask = encoder_padding_mask(x.size(0), supervisions)
if mask is not None:
mask = mask.to(x.device)
x = self.encoder(x, pos_emb, src_key_padding_mask=mask) # (T, B, F)
if self.normalize_before:
x = self.after_norm(x)
return x, mask
class ConformerEncoderLayer(nn.Module):
"""
ConformerEncoderLayer is made up of self-attn, feedforward and convolution networks.
See: "Conformer: Convolution-augmented Transformer for Speech Recognition"
Args:
d_model: the number of expected features in the input (required).
nhead: the number of heads in the multiheadattention models (required).
dim_feedforward: the dimension of the feedforward network model (default=2048).
dropout: the dropout value (default=0.1).
cnn_module_kernel (int): Kernel size of convolution module.
normalize_before: whether to use layer_norm before the first block.
Examples::
>>> encoder_layer = ConformerEncoderLayer(d_model=512, nhead=8)
>>> src = torch.rand(10, 32, 512)
>>> pos_emb = torch.rand(32, 19, 512)
>>> out = encoder_layer(src, pos_emb)
"""
def __init__(
self,
d_model: int,
nhead: int,
dim_feedforward: int = 2048,
dropout: float = 0.1,
cnn_module_kernel: int = 31,
normalize_before: bool = True,
use_conv_batchnorm: bool = False,
) -> None:
super(ConformerEncoderLayer, self).__init__()
self.self_attn = RelPositionMultiheadAttention(d_model, nhead, dropout=0.0)
self.feed_forward = nn.Sequential(
nn.Linear(d_model, dim_feedforward),
Swish(),
nn.Dropout(dropout),
nn.Linear(dim_feedforward, d_model),
)
self.feed_forward_macaron = nn.Sequential(
nn.Linear(d_model, dim_feedforward),
Swish(),
nn.Dropout(dropout),
nn.Linear(dim_feedforward, d_model),
)
self.conv_module = ConvolutionModule(
d_model, cnn_module_kernel, use_batchnorm=use_conv_batchnorm
)
self.norm_ff_macaron = nn.LayerNorm(d_model) # for the macaron style FNN module
self.norm_ff = nn.LayerNorm(d_model) # for the FNN module
self.norm_mha = nn.LayerNorm(d_model) # for the MHA module
self.ff_scale = 0.5
self.norm_conv = nn.LayerNorm(d_model) # for the CNN module
self.norm_final = nn.LayerNorm(d_model) # for the final output of the block
self.dropout = nn.Dropout(dropout)
self.normalize_before = normalize_before
def forward(
self,
src: Tensor,
pos_emb: Tensor,
src_mask: Optional[Tensor] = None,
src_key_padding_mask: Optional[Tensor] = None,
) -> Tensor:
"""
Pass the input through the encoder layer.
Args:
src: the sequence to the encoder layer (required).
pos_emb: Positional embedding tensor (required).
src_mask: the mask for the src sequence (optional).
src_key_padding_mask: the mask for the src keys per batch (optional).
Shape:
src: (S, N, E).
pos_emb: (N, 2*S-1, E)
src_mask: (S, S).
src_key_padding_mask: (N, S).
S is the source sequence length, N is the batch size, E is the feature number
"""
# macaron style feed forward module
residual = src
if self.normalize_before:
src = self.norm_ff_macaron(src)
src = residual + self.ff_scale * self.dropout(self.feed_forward_macaron(src))
if not self.normalize_before:
src = self.norm_ff_macaron(src)
# multi-headed self-attention module
residual = src
if self.normalize_before:
src = self.norm_mha(src)
src_att = self.self_attn(
src,
src,
src,
pos_emb=pos_emb,
attn_mask=src_mask,
key_padding_mask=src_key_padding_mask,
)[0]
src = residual + self.dropout(src_att)
if not self.normalize_before:
src = self.norm_mha(src)
# convolution module
residual = src
if self.normalize_before:
src = self.norm_conv(src)
src = residual + self.dropout(
self.conv_module(src, src_key_padding_mask=src_key_padding_mask)
)
if not self.normalize_before:
src = self.norm_conv(src)
# feed forward module
residual = src
if self.normalize_before:
src = self.norm_ff(src)
src = residual + self.ff_scale * self.dropout(self.feed_forward(src))
if not self.normalize_before:
src = self.norm_ff(src)
if self.normalize_before:
src = self.norm_final(src)
return src
class ConformerEncoder(nn.TransformerEncoder):
r"""ConformerEncoder is a stack of N encoder layers
Args:
encoder_layer: an instance of the ConformerEncoderLayer() class (required).
num_layers: the number of sub-encoder-layers in the encoder (required).
norm: the layer normalization component (optional).
Examples::
>>> encoder_layer = ConformerEncoderLayer(d_model=512, nhead=8)
>>> conformer_encoder = ConformerEncoder(encoder_layer, num_layers=6)
>>> src = torch.rand(10, 32, 512)
>>> pos_emb = torch.rand(32, 19, 512)
>>> out = conformer_encoder(src, pos_emb)
"""
def __init__(
self, encoder_layer: nn.Module, num_layers: int, norm: nn.Module = None
) -> None:
super(ConformerEncoder, self).__init__(
encoder_layer=encoder_layer, num_layers=num_layers, norm=norm
)
def forward(
self,
src: Tensor,
pos_emb: Tensor,
mask: Optional[Tensor] = None,
src_key_padding_mask: Optional[Tensor] = None,
) -> Tensor:
r"""Pass the input through the encoder layers in turn.
Args:
src: the sequence to the encoder (required).
pos_emb: Positional embedding tensor (required).
mask: the mask for the src sequence (optional).
src_key_padding_mask: the mask for the src keys per batch (optional).
Shape:
src: (S, N, E).
pos_emb: (N, 2*S-1, E)
mask: (S, S).
src_key_padding_mask: (N, S).
S is the source sequence length, T is the target sequence length, N is the batch size, E is the feature number
"""
output = src
for mod in self.layers:
output = mod(
output,
pos_emb,
src_mask=mask,
src_key_padding_mask=src_key_padding_mask,
)
if self.norm is not None:
output = self.norm(output)
return output
class RelPositionalEncoding(torch.nn.Module):
"""Relative positional encoding module.
See : Appendix B in "Transformer-XL: Attentive Language Models Beyond a Fixed-Length Context"
Modified from https://github.com/espnet/espnet/blob/master/espnet/nets/pytorch_backend/transformer/embedding.py
Args:
d_model: Embedding dimension.
dropout_rate: Dropout rate.
max_len: Maximum input length.
"""
def __init__(self, d_model: int, dropout_rate: float, max_len: int = 5000) -> None:
"""Construct an PositionalEncoding object."""
super(RelPositionalEncoding, self).__init__()
self.d_model = d_model
self.xscale = math.sqrt(self.d_model)
self.dropout = torch.nn.Dropout(p=dropout_rate)
self.pe = None
self.extend_pe(torch.tensor(0.0).expand(1, max_len))
def extend_pe(self, x: Tensor) -> None:
"""Reset the positional encodings."""
if self.pe is not None:
# self.pe contains both positive and negative parts
# the length of self.pe is 2 * input_len - 1
if self.pe.size(1) >= x.size(1) * 2 - 1:
# Note: TorchScript doesn't implement operator== for torch.Device
if self.pe.dtype != x.dtype or str(self.pe.device) != str(x.device):
self.pe = self.pe.to(dtype=x.dtype, device=x.device)
return
# Suppose `i` means to the position of query vector and `j` means the
# position of key vector. We use position relative positions when keys
# are to the left (i>j) and negative relative positions otherwise (i<j).
pe_positive = torch.zeros(x.size(1), self.d_model)
pe_negative = torch.zeros(x.size(1), self.d_model)
position = torch.arange(0, x.size(1), dtype=torch.float32).unsqueeze(1)
div_term = torch.exp(
torch.arange(0, self.d_model, 2, dtype=torch.float32)
* -(math.log(10000.0) / self.d_model)
)
pe_positive[:, 0::2] = torch.sin(position * div_term)
pe_positive[:, 1::2] = torch.cos(position * div_term)
pe_negative[:, 0::2] = torch.sin(-1 * position * div_term)
pe_negative[:, 1::2] = torch.cos(-1 * position * div_term)
# Reserve the order of positive indices and concat both positive and
# negative indices. This is used to support the shifting trick
# as in "Transformer-XL: Attentive Language Models Beyond a Fixed-Length Context"
pe_positive = torch.flip(pe_positive, [0]).unsqueeze(0)
pe_negative = pe_negative[1:].unsqueeze(0)
pe = torch.cat([pe_positive, pe_negative], dim=1)
self.pe = pe.to(device=x.device, dtype=x.dtype)
def forward(self, x: torch.Tensor) -> Tuple[Tensor, Tensor]:
"""Add positional encoding.
Args:
x (torch.Tensor): Input tensor (batch, time, `*`).
Returns:
torch.Tensor: Encoded tensor (batch, time, `*`).
torch.Tensor: Encoded tensor (batch, 2*time-1, `*`).
"""
self.extend_pe(x)
x = x * self.xscale
pos_emb = self.pe[
:,
self.pe.size(1) // 2
- x.size(1)
+ 1 : self.pe.size(1) // 2 # noqa E203
+ x.size(1),
]
return self.dropout(x), self.dropout(pos_emb)
class RelPositionMultiheadAttention(nn.Module):
r"""Multi-Head Attention layer with relative position encoding
See reference: "Transformer-XL: Attentive Language Models Beyond a Fixed-Length Context"
Args:
embed_dim: total dimension of the model.
num_heads: parallel attention heads.
dropout: a Dropout layer on attn_output_weights. Default: 0.0.
Examples::
>>> rel_pos_multihead_attn = RelPositionMultiheadAttention(embed_dim, num_heads)
>>> attn_output, attn_output_weights = multihead_attn(query, key, value, pos_emb)
"""
def __init__(
self,
embed_dim: int,
num_heads: int,
dropout: float = 0.0,
) -> None:
super(RelPositionMultiheadAttention, self).__init__()
self.embed_dim = embed_dim
self.num_heads = num_heads
self.dropout = dropout
self.head_dim = embed_dim // num_heads
assert (
self.head_dim * num_heads == self.embed_dim
), "embed_dim must be divisible by num_heads"
self.in_proj = nn.Linear(embed_dim, 3 * embed_dim, bias=True)
self.out_proj = nn.Linear(embed_dim, embed_dim, bias=True)
# linear transformation for positional encoding.
self.linear_pos = nn.Linear(embed_dim, embed_dim, bias=False)
# these two learnable bias are used in matrix c and matrix d
# as described in "Transformer-XL: Attentive Language Models Beyond a Fixed-Length Context" Section 3.3
self.pos_bias_u = nn.Parameter(torch.Tensor(num_heads, self.head_dim))
self.pos_bias_v = nn.Parameter(torch.Tensor(num_heads, self.head_dim))
self._reset_parameters()
def _reset_parameters(self) -> None:
nn.init.xavier_uniform_(self.in_proj.weight)
nn.init.constant_(self.in_proj.bias, 0.0)
nn.init.constant_(self.out_proj.bias, 0.0)
nn.init.xavier_uniform_(self.pos_bias_u)
nn.init.xavier_uniform_(self.pos_bias_v)
def forward(
self,
query: Tensor,
key: Tensor,
value: Tensor,
pos_emb: Tensor,
key_padding_mask: Optional[Tensor] = None,
need_weights: bool = True,
attn_mask: Optional[Tensor] = None,
) -> Tuple[Tensor, Optional[Tensor]]:
r"""
Args:
query, key, value: map a query and a set of key-value pairs to an output.
pos_emb: Positional embedding tensor
key_padding_mask: if provided, specified padding elements in the key will
be ignored by the attention. When given a binary mask and a value is True,
the corresponding value on the attention layer will be ignored. When given
a byte mask and a value is non-zero, the corresponding value on the attention
layer will be ignored
need_weights: output attn_output_weights.
attn_mask: 2D or 3D mask that prevents attention to certain positions. A 2D mask will be broadcasted for all
the batches while a 3D mask allows to specify a different mask for the entries of each batch.
Shape:
- Inputs:
- query: :math:`(L, N, E)` where L is the target sequence length, N is the batch size, E is
the embedding dimension.
- key: :math:`(S, N, E)`, where S is the source sequence length, N is the batch size, E is
the embedding dimension.
- value: :math:`(S, N, E)` where S is the source sequence length, N is the batch size, E is
the embedding dimension.
- pos_emb: :math:`(N, 2*L-1, E)` where L is the target sequence length, N is the batch size, E is
the embedding dimension.
- key_padding_mask: :math:`(N, S)` where N is the batch size, S is the source sequence length.
If a ByteTensor is provided, the non-zero positions will be ignored while the position
with the zero positions will be unchanged. If a BoolTensor is provided, the positions with the
value of ``True`` will be ignored while the position with the value of ``False`` will be unchanged.
- attn_mask: 2D mask :math:`(L, S)` where L is the target sequence length, S is the source sequence length.
3D mask :math:`(N*num_heads, L, S)` where N is the batch size, L is the target sequence length,
S is the source sequence length. attn_mask ensure that position i is allowed to attend the unmasked
positions. If a ByteTensor is provided, the non-zero positions are not allowed to attend
while the zero positions will be unchanged. If a BoolTensor is provided, positions with ``True``
is not allowed to attend while ``False`` values will be unchanged. If a FloatTensor
is provided, it will be added to the attention weight.
- Outputs:
- attn_output: :math:`(L, N, E)` where L is the target sequence length, N is the batch size,
E is the embedding dimension.
- attn_output_weights: :math:`(N, L, S)` where N is the batch size,
L is the target sequence length, S is the source sequence length.
"""
return self.multi_head_attention_forward(
query,
key,
value,
pos_emb,
self.embed_dim,
self.num_heads,
self.in_proj.weight,
self.in_proj.bias,
self.dropout,
self.out_proj.weight,
self.out_proj.bias,
training=self.training,
key_padding_mask=key_padding_mask,
need_weights=need_weights,
attn_mask=attn_mask,
)
def rel_shift(self, x: Tensor) -> Tensor:
"""Compute relative positional encoding.
Args:
x: Input tensor (batch, head, time1, 2*time1-1).
time1 means the length of query vector.
Returns:
Tensor: tensor of shape (batch, head, time1, time2)
(note: time2 has the same value as time1, but it is for
the key, while time1 is for the query).
"""
(batch_size, num_heads, time1, n) = x.shape
assert n == 2 * time1 - 1
# Note: TorchScript requires explicit arg for stride()
batch_stride = x.stride(0)
head_stride = x.stride(1)
time1_stride = x.stride(2)
n_stride = x.stride(3)
return x.as_strided(
(batch_size, num_heads, time1, time1),
(batch_stride, head_stride, time1_stride - n_stride, n_stride),
storage_offset=n_stride * (time1 - 1),
)
def multi_head_attention_forward(
self,
query: Tensor,
key: Tensor,
value: Tensor,
pos_emb: Tensor,
embed_dim_to_check: int,
num_heads: int,
in_proj_weight: Tensor,
in_proj_bias: Tensor,
dropout_p: float,
out_proj_weight: Tensor,
out_proj_bias: Tensor,
training: bool = True,
key_padding_mask: Optional[Tensor] = None,
need_weights: bool = True,
attn_mask: Optional[Tensor] = None,
) -> Tuple[Tensor, Optional[Tensor]]:
r"""
Args:
query, key, value: map a query and a set of key-value pairs to an output.
pos_emb: Positional embedding tensor
embed_dim_to_check: total dimension of the model.
num_heads: parallel attention heads.
in_proj_weight, in_proj_bias: input projection weight and bias.
dropout_p: probability of an element to be zeroed.
out_proj_weight, out_proj_bias: the output projection weight and bias.
training: apply dropout if is ``True``.
key_padding_mask: if provided, specified padding elements in the key will
be ignored by the attention. This is an binary mask. When the value is True,
the corresponding value on the attention layer will be filled with -inf.
need_weights: output attn_output_weights.
attn_mask: 2D or 3D mask that prevents attention to certain positions. A 2D mask will be broadcasted for all
the batches while a 3D mask allows to specify a different mask for the entries of each batch.
Shape:
Inputs:
- query: :math:`(L, N, E)` where L is the target sequence length, N is the batch size, E is
the embedding dimension.
- key: :math:`(S, N, E)`, where S is the source sequence length, N is the batch size, E is
the embedding dimension.
- value: :math:`(S, N, E)` where S is the source sequence length, N is the batch size, E is
the embedding dimension.
- pos_emb: :math:`(N, 2*L-1, E)` or :math:`(1, 2*L-1, E)` where L is the target sequence
length, N is the batch size, E is the embedding dimension.
- key_padding_mask: :math:`(N, S)` where N is the batch size, S is the source sequence length.
If a ByteTensor is provided, the non-zero positions will be ignored while the zero positions
will be unchanged. If a BoolTensor is provided, the positions with the
value of ``True`` will be ignored while the position with the value of ``False`` will be unchanged.
- attn_mask: 2D mask :math:`(L, S)` where L is the target sequence length, S is the source sequence length.
3D mask :math:`(N*num_heads, L, S)` where N is the batch size, L is the target sequence length,
S is the source sequence length. attn_mask ensures that position i is allowed to attend the unmasked
positions. If a ByteTensor is provided, the non-zero positions are not allowed to attend
while the zero positions will be unchanged. If a BoolTensor is provided, positions with ``True``
are not allowed to attend while ``False`` values will be unchanged. If a FloatTensor
is provided, it will be added to the attention weight.
Outputs:
- attn_output: :math:`(L, N, E)` where L is the target sequence length, N is the batch size,
E is the embedding dimension.
- attn_output_weights: :math:`(N, L, S)` where N is the batch size,
L is the target sequence length, S is the source sequence length.
"""
tgt_len, bsz, embed_dim = query.size()
assert embed_dim == embed_dim_to_check
assert key.size(0) == value.size(0) and key.size(1) == value.size(1)
head_dim = embed_dim // num_heads
assert (
head_dim * num_heads == embed_dim
), "embed_dim must be divisible by num_heads"
scaling = float(head_dim) ** -0.5
if torch.equal(query, key) and torch.equal(key, value):
# self-attention
q, k, v = nn.functional.linear(query, in_proj_weight, in_proj_bias).chunk(
3, dim=-1
)
elif torch.equal(key, value):
# encoder-decoder attention
# This is inline in_proj function with in_proj_weight and in_proj_bias
_b = in_proj_bias
_start = 0
_end = embed_dim
_w = in_proj_weight[_start:_end, :]
if _b is not None:
_b = _b[_start:_end]
q = nn.functional.linear(query, _w, _b)
# This is inline in_proj function with in_proj_weight and in_proj_bias
_b = in_proj_bias
_start = embed_dim
_end = None
_w = in_proj_weight[_start:, :]
if _b is not None:
_b = _b[_start:]
k, v = nn.functional.linear(key, _w, _b).chunk(2, dim=-1)
else:
# This is inline in_proj function with in_proj_weight and in_proj_bias
_b = in_proj_bias
_start = 0
_end = embed_dim
_w = in_proj_weight[_start:_end, :]
if _b is not None:
_b = _b[_start:_end]
q = nn.functional.linear(query, _w, _b)
# This is inline in_proj function with in_proj_weight and in_proj_bias
_b = in_proj_bias
_start = embed_dim
_end = embed_dim * 2
_w = in_proj_weight[_start:_end, :]
if _b is not None:
_b = _b[_start:_end]
k = nn.functional.linear(key, _w, _b)
# This is inline in_proj function with in_proj_weight and in_proj_bias
_b = in_proj_bias
_start = embed_dim * 2
_end = None
_w = in_proj_weight[_start:, :]
if _b is not None:
_b = _b[_start:]
v = nn.functional.linear(value, _w, _b)
if attn_mask is not None:
assert (
attn_mask.dtype == torch.float32
or attn_mask.dtype == torch.float64
or attn_mask.dtype == torch.float16
or attn_mask.dtype == torch.uint8
or attn_mask.dtype == torch.bool
), "Only float, byte, and bool types are supported for attn_mask, not {}".format(
attn_mask.dtype
)
if attn_mask.dtype == torch.uint8:
warnings.warn(
"Byte tensor for attn_mask is deprecated. Use bool tensor instead."
)
attn_mask = attn_mask.to(torch.bool)
if attn_mask.dim() == 2:
attn_mask = attn_mask.unsqueeze(0)
if list(attn_mask.size()) != [1, query.size(0), key.size(0)]:
raise RuntimeError("The size of the 2D attn_mask is not correct.")
elif attn_mask.dim() == 3:
if list(attn_mask.size()) != [
bsz * num_heads,
query.size(0),
key.size(0),
]:
raise RuntimeError("The size of the 3D attn_mask is not correct.")
else:
raise RuntimeError(
"attn_mask's dimension {} is not supported".format(attn_mask.dim())
)
# attn_mask's dim is 3 now.
# convert ByteTensor key_padding_mask to bool
if key_padding_mask is not None and key_padding_mask.dtype == torch.uint8:
warnings.warn(
"Byte tensor for key_padding_mask is deprecated. Use bool tensor instead."
)
key_padding_mask = key_padding_mask.to(torch.bool)
q = q.contiguous().view(tgt_len, bsz, num_heads, head_dim)
k = k.contiguous().view(-1, bsz, num_heads, head_dim)
v = v.contiguous().view(-1, bsz * num_heads, head_dim).transpose(0, 1)
src_len = k.size(0)
if key_padding_mask is not None:
assert key_padding_mask.size(0) == bsz, "{} == {}".format(
key_padding_mask.size(0), bsz
)
assert key_padding_mask.size(1) == src_len, "{} == {}".format(
key_padding_mask.size(1), src_len
)
q = q.transpose(0, 1) # (batch, time1, head, d_k)
pos_emb_bsz = pos_emb.size(0)
assert pos_emb_bsz in (1, bsz) # actually it is 1
p = self.linear_pos(pos_emb).view(pos_emb_bsz, -1, num_heads, head_dim)
p = p.transpose(1, 2) # (batch, head, 2*time1-1, d_k)
q_with_bias_u = (q + self.pos_bias_u).transpose(
1, 2
) # (batch, head, time1, d_k)
q_with_bias_v = (q + self.pos_bias_v).transpose(
1, 2
) # (batch, head, time1, d_k)
# compute attention score
# first compute matrix a and matrix c
# as described in "Transformer-XL: Attentive Language Models Beyond a Fixed-Length Context" Section 3.3
k = k.permute(1, 2, 3, 0) # (batch, head, d_k, time2)
matrix_ac = torch.matmul(q_with_bias_u, k) # (batch, head, time1, time2)
# compute matrix b and matrix d
matrix_bd = torch.matmul(
q_with_bias_v, p.transpose(-2, -1)
) # (batch, head, time1, 2*time1-1)
matrix_bd = self.rel_shift(matrix_bd)
attn_output_weights = (
matrix_ac + matrix_bd
) * scaling # (batch, head, time1, time2)
attn_output_weights = attn_output_weights.view(bsz * num_heads, tgt_len, -1)
assert list(attn_output_weights.size()) == [
bsz * num_heads,
tgt_len,
src_len,
]
if attn_mask is not None:
if attn_mask.dtype == torch.bool:
attn_output_weights.masked_fill_(attn_mask, float("-inf"))
else:
attn_output_weights += attn_mask
if key_padding_mask is not None:
attn_output_weights = attn_output_weights.view(
bsz, num_heads, tgt_len, src_len
)
attn_output_weights = attn_output_weights.masked_fill(
key_padding_mask.unsqueeze(1).unsqueeze(2),
float("-inf"),
)
attn_output_weights = attn_output_weights.view(
bsz * num_heads, tgt_len, src_len
)
attn_output_weights = nn.functional.softmax(attn_output_weights, dim=-1)
attn_output_weights = nn.functional.dropout(
attn_output_weights, p=dropout_p, training=training
)
attn_output = torch.bmm(attn_output_weights, v)
assert list(attn_output.size()) == [bsz * num_heads, tgt_len, head_dim]
attn_output = (
attn_output.transpose(0, 1).contiguous().view(tgt_len, bsz, embed_dim)
)
attn_output = nn.functional.linear(attn_output, out_proj_weight, out_proj_bias)
if need_weights:
# average attention weights over heads
attn_output_weights = attn_output_weights.view(
bsz, num_heads, tgt_len, src_len
)
return attn_output, attn_output_weights.sum(dim=1) / num_heads
else:
return attn_output, None
class ConvolutionModule(nn.Module):
"""ConvolutionModule in Conformer model.
Modified from https://github.com/espnet/espnet/blob/master/espnet/nets/pytorch_backend/conformer/convolution.py
Args:
channels (int): The number of channels of conv layers.
kernel_size (int): Kernerl size of conv layers.
bias (bool): Whether to use bias in conv layers (default=True).
"""
def __init__(
self,
channels: int,
kernel_size: int,
bias: bool = True,
use_batchnorm: bool = False,
) -> None:
"""Construct an ConvolutionModule object."""
super(ConvolutionModule, self).__init__()
# kernerl_size should be a odd number for 'SAME' padding
assert (kernel_size - 1) % 2 == 0
self.use_batchnorm = use_batchnorm
self.pointwise_conv1 = nn.Conv1d(
channels,
2 * channels,
kernel_size=1,
stride=1,
padding=0,
bias=bias,
)
self.depthwise_conv = nn.Conv1d(
channels,
channels,
kernel_size,
stride=1,
padding=(kernel_size - 1) // 2,
groups=channels,
bias=bias,
)
if self.use_batchnorm:
self.norm = nn.BatchNorm1d(channels)
self.pointwise_conv2 = nn.Conv1d(
channels,
channels,
kernel_size=1,
stride=1,
padding=0,
bias=bias,
)
self.activation = Swish()
def forward(
self,
x: Tensor,
src_key_padding_mask: Optional[Tensor] = None,
) -> Tensor:
"""Compute convolution module.
Args:
x: Input tensor (#time, batch, channels).
src_key_padding_mask: the mask for the src keys per batch (optional).
Returns:
Tensor: Output tensor (#time, batch, channels).
"""
# exchange the temporal dimension and the feature dimension
x = x.permute(1, 2, 0) # (#batch, channels, time).
# GLU mechanism
x = self.pointwise_conv1(x) # (batch, 2*channels, time)
x = nn.functional.glu(x, dim=1) # (batch, channels, time)
# 1D Depthwise Conv
if src_key_padding_mask is not None:
x.masked_fill_(src_key_padding_mask.unsqueeze(1).expand_as(x), 0.0)
x = self.depthwise_conv(x)
if self.use_batchnorm:
x = self.norm(x)
x = self.activation(x)
x = self.pointwise_conv2(x) # (batch, channel, time)
return x.permute(2, 0, 1)
class Swish(torch.nn.Module):
"""Construct an Swish object."""
def forward(self, x: Tensor) -> Tensor:
"""Return Swich activation function."""
return x * torch.sigmoid(x)
def identity(x):
return x

View File

@ -0,0 +1 @@
../../../librispeech/ASR/conformer_ctc/conformer.py

View File

@ -1,163 +0,0 @@
#!/usr/bin/env python3
#
# Copyright 2021 Xiaomi Corporation (Author: Fangjun Kuang)
#
# See ../../../../LICENSE for clarification regarding multiple authors
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# This script converts several saved checkpoints
# to a single one using model averaging.
import argparse
import logging
from pathlib import Path
import torch
from conformer import Conformer
from icefall.checkpoint import average_checkpoints, load_checkpoint
from icefall.lexicon import Lexicon
from icefall.utils import AttributeDict, str2bool
def get_parser():
parser = argparse.ArgumentParser(
formatter_class=argparse.ArgumentDefaultsHelpFormatter
)
parser.add_argument(
"--epoch",
type=int,
default=34,
help="It specifies the checkpoint to use for decoding."
"Note: Epoch counts from 0.",
)
parser.add_argument(
"--avg",
type=int,
default=20,
help="Number of checkpoints to average. Automatically select "
"consecutive checkpoints before the checkpoint specified by "
"'--epoch'. ",
)
parser.add_argument(
"--exp-dir",
type=str,
default="conformer_ctc/exp",
help="""It specifies the directory where all training related
files, e.g., checkpoints, log, etc, are saved
""",
)
parser.add_argument(
"--lang-dir",
type=str,
default="data/lang_bpe_500",
help="""It contains language related input files such as "lexicon.txt"
""",
)
parser.add_argument(
"--jit",
type=str2bool,
default=True,
help="""True to save a model after applying torch.jit.script.
""",
)
return parser
def get_params() -> AttributeDict:
params = AttributeDict(
{
"feature_dim": 80,
"subsampling_factor": 4,
"use_feat_batchnorm": True,
"attention_dim": 512,
"nhead": 8,
"num_decoder_layers": 6,
}
)
return params
def main():
args = get_parser().parse_args()
args.exp_dir = Path(args.exp_dir)
args.lang_dir = Path(args.lang_dir)
params = get_params()
params.update(vars(args))
logging.info(params)
lexicon = Lexicon(params.lang_dir)
max_token_id = max(lexicon.tokens)
num_classes = max_token_id + 1 # +1 for the blank
device = torch.device("cpu")
if torch.cuda.is_available():
device = torch.device("cuda", 0)
logging.info(f"device: {device}")
model = Conformer(
num_features=params.feature_dim,
nhead=params.nhead,
d_model=params.attention_dim,
num_classes=num_classes,
subsampling_factor=params.subsampling_factor,
num_decoder_layers=params.num_decoder_layers,
vgg_frontend=False,
use_feat_batchnorm=params.use_feat_batchnorm,
)
model.to(device)
if params.avg == 1:
load_checkpoint(f"{params.exp_dir}/epoch-{params.epoch}.pt", model)
else:
start = params.epoch - params.avg + 1
filenames = []
for i in range(start, params.epoch + 1):
if start >= 0:
filenames.append(f"{params.exp_dir}/epoch-{i}.pt")
logging.info(f"averaging {filenames}")
model.load_state_dict(average_checkpoints(filenames))
model.to("cpu")
model.eval()
if params.jit:
logging.info("Using torch.jit.script")
model = torch.jit.script(model)
filename = params.exp_dir / "cpu_jit.pt"
model.save(str(filename))
logging.info(f"Saved to {filename}")
else:
logging.info("Not using torch.jit.script")
# Save it using a format so that it can be loaded
# by :func:`load_checkpoint`
filename = params.exp_dir / "pretrained.pt"
torch.save({"model": model.state_dict()}, str(filename))
logging.info(f"Saved to {filename}")
if __name__ == "__main__":
formatter = "%(asctime)s %(levelname)s [%(filename)s:%(lineno)d] %(message)s"
logging.basicConfig(format=formatter, level=logging.INFO)
main()

View File

@ -0,0 +1 @@
../../../librispeech/ASR/conformer_ctc/export.py

View File

@ -1,109 +0,0 @@
# Copyright 2021 Xiaomi Corp. (authors: Fangjun Kuang)
#
# See ../../../../LICENSE for clarification regarding multiple authors
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import torch
class LabelSmoothingLoss(torch.nn.Module):
"""
Implement the LabelSmoothingLoss proposed in the following paper
https://arxiv.org/pdf/1512.00567.pdf
(Rethinking the Inception Architecture for Computer Vision)
"""
def __init__(
self,
ignore_index: int = -1,
label_smoothing: float = 0.1,
reduction: str = "sum",
) -> None:
"""
Args:
ignore_index:
ignored class id
label_smoothing:
smoothing rate (0.0 means the conventional cross entropy loss)
reduction:
It has the same meaning as the reduction in
`torch.nn.CrossEntropyLoss`. It can be one of the following three
values: (1) "none": No reduction will be applied. (2) "mean": the
mean of the output is taken. (3) "sum": the output will be summed.
"""
super().__init__()
assert 0.0 <= label_smoothing < 1.0, f"{label_smoothing}"
assert reduction in ("none", "sum", "mean"), reduction
self.ignore_index = ignore_index
self.label_smoothing = label_smoothing
self.reduction = reduction
def forward(self, x: torch.Tensor, target: torch.Tensor) -> torch.Tensor:
"""
Compute loss between x and target.
Args:
x:
prediction of dimension
(batch_size, input_length, number_of_classes).
target:
target masked with self.ignore_index of
dimension (batch_size, input_length).
Returns:
A scalar tensor containing the loss without normalization.
"""
assert x.ndim == 3
assert target.ndim == 2
assert x.shape[:2] == target.shape
num_classes = x.size(-1)
x = x.reshape(-1, num_classes)
# Now x is of shape (N*T, C)
# We don't want to change target in-place below,
# so we make a copy of it here
target = target.clone().reshape(-1)
ignored = target == self.ignore_index
# See https://github.com/k2-fsa/icefall/issues/240
# and https://github.com/k2-fsa/icefall/issues/297
# for why we don't use target[ignored] = 0 here
target = torch.where(ignored, torch.zeros_like(target), target)
true_dist = torch.nn.functional.one_hot(target, num_classes=num_classes).to(x)
true_dist = (
true_dist * (1 - self.label_smoothing) + self.label_smoothing / num_classes
)
# Set the value of ignored indexes to 0
#
# See https://github.com/k2-fsa/icefall/issues/240
# and https://github.com/k2-fsa/icefall/issues/297
# for why we don't use true_dist[ignored] = 0 here
true_dist = torch.where(
ignored.unsqueeze(1).repeat(1, true_dist.shape[1]),
torch.zeros_like(true_dist),
true_dist,
)
loss = -1 * (torch.log_softmax(x, dim=1) * true_dist)
if self.reduction == "sum":
return loss.sum()
elif self.reduction == "mean":
return loss.sum() / (~ignored).sum()
else:
return loss.sum(dim=-1)

View File

@ -0,0 +1 @@
../../../librispeech/ASR/conformer_ctc/label_smoothing.py

View File

@ -1,430 +0,0 @@
#!/usr/bin/env python3
# Copyright 2021 Xiaomi Corp. (authors: Fangjun Kuang,
# Mingshuang Luo)
#
# See ../../../../LICENSE for clarification regarding multiple authors
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import argparse
import logging
import math
from typing import List
import k2
import kaldifeat
import sentencepiece as spm
import torch
import torchaudio
from conformer import Conformer
from torch.nn.utils.rnn import pad_sequence
from icefall.decode import (
get_lattice,
one_best_decoding,
rescore_with_attention_decoder,
rescore_with_whole_lattice,
)
from icefall.utils import AttributeDict, get_texts
def get_parser():
parser = argparse.ArgumentParser(
formatter_class=argparse.ArgumentDefaultsHelpFormatter
)
parser.add_argument(
"--checkpoint",
type=str,
required=True,
help="Path to the checkpoint. "
"The checkpoint is assumed to be saved by "
"icefall.checkpoint.save_checkpoint().",
)
parser.add_argument(
"--words-file",
type=str,
help="""Path to words.txt.
Used only when method is not ctc-decoding.
""",
)
parser.add_argument(
"--HLG",
type=str,
help="""Path to HLG.pt.
Used only when method is not ctc-decoding.
""",
)
parser.add_argument(
"--bpe-model",
type=str,
help="""Path to bpe.model.
Used only when method is ctc-decoding.
""",
)
parser.add_argument(
"--method",
type=str,
default="1best",
help="""Decoding method.
Possible values are:
(0) ctc-decoding - Use CTC decoding. It uses a sentence
piece model, i.e., lang_dir/bpe.model, to convert
word pieces to words. It needs neither a lexicon
nor an n-gram LM.
(1) 1best - Use the best path as decoding output. Only
the transformer encoder output is used for decoding.
We call it HLG decoding.
(2) whole-lattice-rescoring - Use an LM to rescore the
decoding lattice and then use 1best to decode the
rescored lattice.
We call it HLG decoding + n-gram LM rescoring.
(3) attention-decoder - Extract n paths from the rescored
lattice and use the transformer attention decoder for
rescoring.
We call it HLG decoding + n-gram LM rescoring + attention
decoder rescoring.
""",
)
parser.add_argument(
"--G",
type=str,
help="""An LM for rescoring.
Used only when method is
whole-lattice-rescoring or attention-decoder.
It's usually a 4-gram LM.
""",
)
parser.add_argument(
"--num-paths",
type=int,
default=100,
help="""
Used only when method is attention-decoder.
It specifies the size of n-best list.""",
)
parser.add_argument(
"--ngram-lm-scale",
type=float,
default=1.3,
help="""
Used only when method is whole-lattice-rescoring and attention-decoder.
It specifies the scale for n-gram LM scores.
(Note: You need to tune it on a dataset.)
""",
)
parser.add_argument(
"--attention-decoder-scale",
type=float,
default=1.2,
help="""
Used only when method is attention-decoder.
It specifies the scale for attention decoder scores.
(Note: You need to tune it on a dataset.)
""",
)
parser.add_argument(
"--nbest-scale",
type=float,
default=0.5,
help="""
Used only when method is attention-decoder.
It specifies the scale for lattice.scores when
extracting n-best lists. A smaller value results in
more unique number of paths with the risk of missing
the best path.
""",
)
parser.add_argument(
"--sos-id",
type=int,
default=1,
help="""
Used only when method is attention-decoder.
It specifies ID for the SOS token.
""",
)
parser.add_argument(
"--num-classes",
type=int,
default=500,
help="""
Vocab size in the BPE model.
""",
)
parser.add_argument(
"--eos-id",
type=int,
default=1,
help="""
Used only when method is attention-decoder.
It specifies ID for the EOS token.
""",
)
parser.add_argument(
"sound_files",
type=str,
nargs="+",
help="The input sound file(s) to transcribe. "
"Supported formats are those supported by torchaudio.load(). "
"For example, wav and flac are supported. "
"The sample rate has to be 16kHz.",
)
return parser
def get_params() -> AttributeDict:
params = AttributeDict(
{
"sample_rate": 16000,
# parameters for conformer
"subsampling_factor": 4,
"vgg_frontend": False,
"use_feat_batchnorm": True,
"feature_dim": 80,
"nhead": 8,
"attention_dim": 512,
"num_decoder_layers": 6,
# parameters for decoding
"search_beam": 20,
"output_beam": 8,
"min_active_states": 30,
"max_active_states": 10000,
"use_double_scores": True,
}
)
return params
def read_sound_files(
filenames: List[str], expected_sample_rate: float
) -> List[torch.Tensor]:
"""Read a list of sound files into a list 1-D float32 torch tensors.
Args:
filenames:
A list of sound filenames.
expected_sample_rate:
The expected sample rate of the sound files.
Returns:
Return a list of 1-D float32 torch tensors.
"""
ans = []
for f in filenames:
wave, sample_rate = torchaudio.load(f)
assert (
sample_rate == expected_sample_rate
), f"expected sample rate: {expected_sample_rate}. Given: {sample_rate}"
# We use only the first channel
ans.append(wave[0])
return ans
def main():
parser = get_parser()
args = parser.parse_args()
params = get_params()
if args.method != "attention-decoder":
# to save memory as the attention decoder
# will not be used
params.num_decoder_layers = 0
params.update(vars(args))
logging.info(f"{params}")
device = torch.device("cpu")
if torch.cuda.is_available():
device = torch.device("cuda", 0)
logging.info(f"device: {device}")
logging.info("Creating model")
model = Conformer(
num_features=params.feature_dim,
nhead=params.nhead,
d_model=params.attention_dim,
num_classes=params.num_classes,
subsampling_factor=params.subsampling_factor,
num_decoder_layers=params.num_decoder_layers,
vgg_frontend=params.vgg_frontend,
use_feat_batchnorm=params.use_feat_batchnorm,
)
checkpoint = torch.load(args.checkpoint, map_location="cpu")
model.load_state_dict(checkpoint["model"], strict=False)
model.to(device)
model.eval()
logging.info("Constructing Fbank computer")
opts = kaldifeat.FbankOptions()
opts.device = device
opts.frame_opts.dither = 0
opts.frame_opts.snip_edges = False
opts.frame_opts.samp_freq = params.sample_rate
opts.mel_opts.num_bins = params.feature_dim
fbank = kaldifeat.Fbank(opts)
logging.info(f"Reading sound files: {params.sound_files}")
waves = read_sound_files(
filenames=params.sound_files, expected_sample_rate=params.sample_rate
)
waves = [w.to(device) for w in waves]
logging.info("Decoding started")
features = fbank(waves)
features = pad_sequence(features, batch_first=True, padding_value=math.log(1e-10))
# Note: We don't use key padding mask for attention during decoding
with torch.no_grad():
nnet_output, memory, memory_key_padding_mask = model(features)
batch_size = nnet_output.shape[0]
supervision_segments = torch.tensor(
[[i, 0, nnet_output.shape[1]] for i in range(batch_size)],
dtype=torch.int32,
)
if params.method == "ctc-decoding":
logging.info("Use CTC decoding")
bpe_model = spm.SentencePieceProcessor()
bpe_model.load(params.bpe_model)
max_token_id = params.num_classes - 1
H = k2.ctc_topo(
max_token=max_token_id,
modified=params.num_classes > 500,
device=device,
)
lattice = get_lattice(
nnet_output=nnet_output,
decoding_graph=H,
supervision_segments=supervision_segments,
search_beam=params.search_beam,
output_beam=params.output_beam,
min_active_states=params.min_active_states,
max_active_states=params.max_active_states,
subsampling_factor=params.subsampling_factor,
)
best_path = one_best_decoding(
lattice=lattice, use_double_scores=params.use_double_scores
)
token_ids = get_texts(best_path)
hyps = bpe_model.decode(token_ids)
hyps = [s.split() for s in hyps]
elif params.method in [
"1best",
"whole-lattice-rescoring",
"attention-decoder",
]:
logging.info(f"Loading HLG from {params.HLG}")
HLG = k2.Fsa.from_dict(torch.load(params.HLG, map_location="cpu"))
HLG = HLG.to(device)
if not hasattr(HLG, "lm_scores"):
# For whole-lattice-rescoring and attention-decoder
HLG.lm_scores = HLG.scores.clone()
if params.method in [
"whole-lattice-rescoring",
"attention-decoder",
]:
logging.info(f"Loading G from {params.G}")
G = k2.Fsa.from_dict(torch.load(params.G, map_location="cpu"))
# Add epsilon self-loops to G as we will compose
# it with the whole lattice later
G = G.to(device)
G = k2.add_epsilon_self_loops(G)
G = k2.arc_sort(G)
G.lm_scores = G.scores.clone()
lattice = get_lattice(
nnet_output=nnet_output,
decoding_graph=HLG,
supervision_segments=supervision_segments,
search_beam=params.search_beam,
output_beam=params.output_beam,
min_active_states=params.min_active_states,
max_active_states=params.max_active_states,
subsampling_factor=params.subsampling_factor,
)
if params.method == "1best":
logging.info("Use HLG decoding")
best_path = one_best_decoding(
lattice=lattice, use_double_scores=params.use_double_scores
)
elif params.method == "whole-lattice-rescoring":
logging.info("Use HLG decoding + LM rescoring")
best_path_dict = rescore_with_whole_lattice(
lattice=lattice,
G_with_epsilon_loops=G,
lm_scale_list=[params.ngram_lm_scale],
)
best_path = next(iter(best_path_dict.values()))
elif params.method == "attention-decoder":
logging.info("Use HLG + LM rescoring + attention decoder rescoring")
rescored_lattice = rescore_with_whole_lattice(
lattice=lattice, G_with_epsilon_loops=G, lm_scale_list=None
)
best_path_dict = rescore_with_attention_decoder(
lattice=rescored_lattice,
num_paths=params.num_paths,
model=model,
memory=memory,
memory_key_padding_mask=memory_key_padding_mask,
sos_id=params.sos_id,
eos_id=params.eos_id,
nbest_scale=params.nbest_scale,
ngram_lm_scale=params.ngram_lm_scale,
attention_scale=params.attention_decoder_scale,
)
best_path = next(iter(best_path_dict.values()))
hyps = get_texts(best_path)
word_sym_table = k2.SymbolTable.from_file(params.words_file)
hyps = [[word_sym_table[i] for i in ids] for ids in hyps]
else:
raise ValueError(f"Unsupported decoding method: {params.method}")
s = "\n"
for filename, hyp in zip(params.sound_files, hyps):
words = " ".join(hyp)
s += f"{filename}:\n{words}\n\n"
logging.info(s)
logging.info("Decoding Done")
if __name__ == "__main__":
formatter = "%(asctime)s %(levelname)s [%(filename)s:%(lineno)d] %(message)s"
logging.basicConfig(format=formatter, level=logging.INFO)
main()

View File

@ -0,0 +1 @@
../../../librispeech/ASR/conformer_ctc/pretrained.py

View File

@ -1,153 +0,0 @@
# Copyright 2021 Xiaomi Corp. (authors: Fangjun Kuang)
#
# See ../../../../LICENSE for clarification regarding multiple authors
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import torch
import torch.nn as nn
class Conv2dSubsampling(nn.Module):
"""Convolutional 2D subsampling (to 1/4 length).
Convert an input of shape (N, T, idim) to an output
with shape (N, T', odim), where
T' = ((T-1)//2 - 1)//2, which approximates T' == T//4
It is based on
https://github.com/espnet/espnet/blob/master/espnet/nets/pytorch_backend/transformer/subsampling.py # noqa
"""
def __init__(self, idim: int, odim: int) -> None:
"""
Args:
idim:
Input dim. The input shape is (N, T, idim).
Caution: It requires: T >=7, idim >=7
odim:
Output dim. The output shape is (N, ((T-1)//2 - 1)//2, odim)
"""
assert idim >= 7
super().__init__()
self.conv = nn.Sequential(
nn.Conv2d(in_channels=1, out_channels=odim, kernel_size=3, stride=2),
nn.ReLU(),
nn.Conv2d(in_channels=odim, out_channels=odim, kernel_size=3, stride=2),
nn.ReLU(),
)
self.out = nn.Linear(odim * (((idim - 1) // 2 - 1) // 2), odim)
def forward(self, x: torch.Tensor) -> torch.Tensor:
"""Subsample x.
Args:
x:
Its shape is (N, T, idim).
Returns:
Return a tensor of shape (N, ((T-1)//2 - 1)//2, odim)
"""
# On entry, x is (N, T, idim)
x = x.unsqueeze(1) # (N, T, idim) -> (N, 1, T, idim) i.e., (N, C, H, W)
x = self.conv(x)
# Now x is of shape (N, odim, ((T-1)//2 - 1)//2, ((idim-1)//2 - 1)//2)
b, c, t, f = x.size()
x = self.out(x.transpose(1, 2).contiguous().view(b, t, c * f))
# Now x is of shape (N, ((T-1)//2 - 1))//2, odim)
return x
class VggSubsampling(nn.Module):
"""Trying to follow the setup described in the following paper:
https://arxiv.org/pdf/1910.09799.pdf
This paper is not 100% explicit so I am guessing to some extent,
and trying to compare with other VGG implementations.
Convert an input of shape (N, T, idim) to an output
with shape (N, T', odim), where
T' = ((T-1)//2 - 1)//2, which approximates T' = T//4
"""
def __init__(self, idim: int, odim: int) -> None:
"""Construct a VggSubsampling object.
This uses 2 VGG blocks with 2 Conv2d layers each,
subsampling its input by a factor of 4 in the time dimensions.
Args:
idim:
Input dim. The input shape is (N, T, idim).
Caution: It requires: T >=7, idim >=7
odim:
Output dim. The output shape is (N, ((T-1)//2 - 1)//2, odim)
"""
super().__init__()
cur_channels = 1
layers = []
block_dims = [32, 64]
# The decision to use padding=1 for the 1st convolution, then padding=0
# for the 2nd and for the max-pooling, and ceil_mode=True, was driven by
# a back-compatibility concern so that the number of frames at the
# output would be equal to:
# (((T-1)//2)-1)//2.
# We can consider changing this by using padding=1 on the
# 2nd convolution, so the num-frames at the output would be T//4.
for block_dim in block_dims:
layers.append(
torch.nn.Conv2d(
in_channels=cur_channels,
out_channels=block_dim,
kernel_size=3,
padding=1,
stride=1,
)
)
layers.append(torch.nn.ReLU())
layers.append(
torch.nn.Conv2d(
in_channels=block_dim,
out_channels=block_dim,
kernel_size=3,
padding=0,
stride=1,
)
)
layers.append(
torch.nn.MaxPool2d(kernel_size=2, stride=2, padding=0, ceil_mode=True)
)
cur_channels = block_dim
self.layers = nn.Sequential(*layers)
self.out = nn.Linear(block_dims[-1] * (((idim - 1) // 2 - 1) // 2), odim)
def forward(self, x: torch.Tensor) -> torch.Tensor:
"""Subsample x.
Args:
x:
Its shape is (N, T, idim).
Returns:
Return a tensor of shape (N, ((T-1)//2 - 1)//2, odim)
"""
x = x.unsqueeze(1)
x = self.layers(x)
b, c, t, f = x.size()
x = self.out(x.transpose(1, 2).contiguous().view(b, t, c * f))
return x

View File

@ -0,0 +1 @@
../../../librispeech/ASR/conformer_ctc/subsampling.py

View File

@ -1,52 +0,0 @@
#!/usr/bin/env python3
# Copyright 2021 Xiaomi Corp. (authors: Fangjun Kuang)
#
# See ../../../../LICENSE for clarification regarding multiple authors
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
from distutils.version import LooseVersion
import torch
from label_smoothing import LabelSmoothingLoss
torch_ver = LooseVersion(torch.__version__)
def test_with_torch_label_smoothing_loss():
if torch_ver < LooseVersion("1.10.0"):
print(f"Current torch version: {torch_ver}")
print("Please use torch >= 1.10 to run this test - skipping")
return
torch.manual_seed(20211105)
x = torch.rand(20, 30, 5000)
tgt = torch.randint(low=-1, high=x.size(-1), size=x.shape[:2])
for reduction in ["none", "sum", "mean"]:
custom_loss_func = LabelSmoothingLoss(
ignore_index=-1, label_smoothing=0.1, reduction=reduction
)
custom_loss = custom_loss_func(x, tgt)
torch_loss_func = torch.nn.CrossEntropyLoss(
ignore_index=-1, reduction=reduction, label_smoothing=0.1
)
torch_loss = torch_loss_func(x.reshape(-1, x.size(-1)), tgt.reshape(-1))
assert torch.allclose(custom_loss, torch_loss)
def main():
test_with_torch_label_smoothing_loss()
if __name__ == "__main__":
main()

View File

@ -0,0 +1 @@
../../../librispeech/ASR/conformer_ctc/test_label_smoothing.py

View File

@ -1,48 +0,0 @@
#!/usr/bin/env python3
# Copyright 2021 Xiaomi Corp. (authors: Fangjun Kuang)
#
# See ../../../../LICENSE for clarification regarding multiple authors
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import torch
from subsampling import Conv2dSubsampling, VggSubsampling
def test_conv2d_subsampling():
N = 3
odim = 2
for T in range(7, 19):
for idim in range(7, 20):
model = Conv2dSubsampling(idim=idim, odim=odim)
x = torch.empty(N, T, idim)
y = model(x)
assert y.shape[0] == N
assert y.shape[1] == ((T - 1) // 2 - 1) // 2
assert y.shape[2] == odim
def test_vgg_subsampling():
N = 3
odim = 2
for T in range(7, 19):
for idim in range(7, 20):
model = VggSubsampling(idim=idim, odim=odim)
x = torch.empty(N, T, idim)
y = model(x)
assert y.shape[0] == N
assert y.shape[1] == ((T - 1) // 2 - 1) // 2
assert y.shape[2] == odim

View File

@ -0,0 +1 @@
../../../librispeech/ASR/conformer_ctc/test_subsampling.py

View File

@ -1,104 +0,0 @@
#!/usr/bin/env python3
# Copyright 2021 Xiaomi Corp. (authors: Fangjun Kuang)
#
# See ../../../../LICENSE for clarification regarding multiple authors
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import torch
from torch.nn.utils.rnn import pad_sequence
from transformer import (
Transformer,
add_eos,
add_sos,
decoder_padding_mask,
encoder_padding_mask,
generate_square_subsequent_mask,
)
def test_encoder_padding_mask():
supervisions = {
"sequence_idx": torch.tensor([0, 1, 2]),
"start_frame": torch.tensor([0, 0, 0]),
"num_frames": torch.tensor([18, 7, 13]),
}
max_len = ((18 - 1) // 2 - 1) // 2
mask = encoder_padding_mask(max_len, supervisions)
expected_mask = torch.tensor(
[
[False, False, False], # ((18 - 1)//2 - 1)//2 = 3,
[False, True, True], # ((7 - 1)//2 - 1)//2 = 1,
[False, False, True], # ((13 - 1)//2 - 1)//2 = 2,
]
)
assert torch.all(torch.eq(mask, expected_mask))
def test_transformer():
num_features = 40
num_classes = 87
model = Transformer(num_features=num_features, num_classes=num_classes)
N = 31
for T in range(7, 30):
x = torch.rand(N, T, num_features)
y, _, _ = model(x)
assert y.shape == (N, (((T - 1) // 2) - 1) // 2, num_classes)
def test_generate_square_subsequent_mask():
s = 5
mask = generate_square_subsequent_mask(s)
inf = float("inf")
expected_mask = torch.tensor(
[
[0.0, -inf, -inf, -inf, -inf],
[0.0, 0.0, -inf, -inf, -inf],
[0.0, 0.0, 0.0, -inf, -inf],
[0.0, 0.0, 0.0, 0.0, -inf],
[0.0, 0.0, 0.0, 0.0, 0.0],
]
)
assert torch.all(torch.eq(mask, expected_mask))
def test_decoder_padding_mask():
x = [torch.tensor([1, 2]), torch.tensor([3]), torch.tensor([2, 5, 8])]
y = pad_sequence(x, batch_first=True, padding_value=-1)
mask = decoder_padding_mask(y, ignore_id=-1)
expected_mask = torch.tensor(
[
[False, False, True],
[False, True, True],
[False, False, False],
]
)
assert torch.all(torch.eq(mask, expected_mask))
def test_add_sos():
x = [[1, 2], [3], [2, 5, 8]]
y = add_sos(x, sos_id=0)
expected_y = [[0, 1, 2], [0, 3], [0, 2, 5, 8]]
assert y == expected_y
def test_add_eos():
x = [[1, 2], [3], [2, 5, 8]]
y = add_eos(x, eos_id=0)
expected_y = [[1, 2, 0], [3, 0], [2, 5, 8, 0]]
assert y == expected_y

View File

@ -0,0 +1 @@
../../../librispeech/ASR/conformer_ctc/test_transformer.py

View File

@ -1,928 +0,0 @@
# Copyright 2021 University of Chinese Academy of Sciences (author: Han Zhu)
#
# See ../../../../LICENSE for clarification regarding multiple authors
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import math
from typing import Dict, List, Optional, Tuple, Union
import torch
import torch.nn as nn
from label_smoothing import LabelSmoothingLoss
from subsampling import Conv2dSubsampling, VggSubsampling
from torch.nn.utils.rnn import pad_sequence
# Note: TorchScript requires Dict/List/etc. to be fully typed.
Supervisions = Dict[str, torch.Tensor]
class Transformer(nn.Module):
def __init__(
self,
num_features: int,
num_classes: int,
subsampling_factor: int = 4,
d_model: int = 256,
nhead: int = 4,
dim_feedforward: int = 2048,
num_encoder_layers: int = 12,
num_decoder_layers: int = 6,
dropout: float = 0.1,
normalize_before: bool = True,
vgg_frontend: bool = False,
use_feat_batchnorm: Union[float, bool] = 0.1,
) -> None:
"""
Args:
num_features:
The input dimension of the model.
num_classes:
The output dimension of the model.
subsampling_factor:
Number of output frames is num_in_frames // subsampling_factor.
Currently, subsampling_factor MUST be 4.
d_model:
Attention dimension.
nhead:
Number of heads in multi-head attention.
Must satisfy d_model // nhead == 0.
dim_feedforward:
The output dimension of the feedforward layers in encoder/decoder.
num_encoder_layers:
Number of encoder layers.
num_decoder_layers:
Number of decoder layers.
dropout:
Dropout in encoder/decoder.
normalize_before:
If True, use pre-layer norm; False to use post-layer norm.
vgg_frontend:
True to use vgg style frontend for subsampling.
use_feat_batchnorm:
True to use batchnorm for the input layer.
Float value to scale the input layer.
False to do nothing.
"""
super().__init__()
self.use_feat_batchnorm = use_feat_batchnorm
assert isinstance(use_feat_batchnorm, (float, bool))
if isinstance(use_feat_batchnorm, bool) and use_feat_batchnorm:
self.feat_batchnorm = nn.BatchNorm1d(num_features)
self.num_features = num_features
self.num_classes = num_classes
self.subsampling_factor = subsampling_factor
if subsampling_factor != 4:
raise NotImplementedError("Support only 'subsampling_factor=4'.")
# self.encoder_embed converts the input of shape (N, T, num_classes)
# to the shape (N, T//subsampling_factor, d_model).
# That is, it does two things simultaneously:
# (1) subsampling: T -> T//subsampling_factor
# (2) embedding: num_classes -> d_model
if vgg_frontend:
self.encoder_embed = VggSubsampling(num_features, d_model)
else:
self.encoder_embed = Conv2dSubsampling(num_features, d_model)
self.encoder_pos = PositionalEncoding(d_model, dropout)
encoder_layer = TransformerEncoderLayer(
d_model=d_model,
nhead=nhead,
dim_feedforward=dim_feedforward,
dropout=dropout,
normalize_before=normalize_before,
)
if normalize_before:
encoder_norm = nn.LayerNorm(d_model)
else:
encoder_norm = None
self.encoder = nn.TransformerEncoder(
encoder_layer=encoder_layer,
num_layers=num_encoder_layers,
norm=encoder_norm,
)
# TODO(fangjun): remove dropout
self.encoder_output_layer = nn.Sequential(
nn.Dropout(p=dropout), nn.Linear(d_model, num_classes)
)
if num_decoder_layers > 0:
self.decoder_num_class = (
self.num_classes
) # bpe model already has sos/eos symbol
self.decoder_embed = nn.Embedding(
num_embeddings=self.decoder_num_class, embedding_dim=d_model
)
self.decoder_pos = PositionalEncoding(d_model, dropout)
decoder_layer = TransformerDecoderLayer(
d_model=d_model,
nhead=nhead,
dim_feedforward=dim_feedforward,
dropout=dropout,
normalize_before=normalize_before,
)
if normalize_before:
decoder_norm = nn.LayerNorm(d_model)
else:
decoder_norm = None
self.decoder = nn.TransformerDecoder(
decoder_layer=decoder_layer,
num_layers=num_decoder_layers,
norm=decoder_norm,
)
self.decoder_output_layer = torch.nn.Linear(d_model, self.decoder_num_class)
self.decoder_criterion = LabelSmoothingLoss()
else:
self.decoder_criterion = None
def forward(
self, x: torch.Tensor, supervision: Optional[Supervisions] = None
) -> Tuple[torch.Tensor, torch.Tensor, Optional[torch.Tensor]]:
"""
Args:
x:
The input tensor. Its shape is (N, T, C).
supervision:
Supervision in lhotse format.
See https://github.com/lhotse-speech/lhotse/blob/master/lhotse/dataset/speech_recognition.py#L32 # noqa
(CAUTION: It contains length information, i.e., start and number of
frames, before subsampling)
Returns:
Return a tuple containing 3 tensors:
- CTC output for ctc decoding. Its shape is (N, T, C)
- Encoder output with shape (T, N, C). It can be used as key and
value for the decoder.
- Encoder output padding mask. It can be used as
memory_key_padding_mask for the decoder. Its shape is (N, T).
It is None if `supervision` is None.
"""
if isinstance(self.use_feat_batchnorm, bool) and self.use_feat_batchnorm:
x = x.permute(0, 2, 1) # (N, T, C) -> (N, C, T)
x = self.feat_batchnorm(x)
x = x.permute(0, 2, 1) # (N, C, T) -> (N, T, C)
if isinstance(self.use_feat_batchnorm, float):
x *= self.use_feat_batchnorm
encoder_memory, memory_key_padding_mask = self.run_encoder(x, supervision)
x = self.ctc_output(encoder_memory)
return x, encoder_memory, memory_key_padding_mask
def run_encoder(
self, x: torch.Tensor, supervisions: Optional[Supervisions] = None
) -> Tuple[torch.Tensor, Optional[torch.Tensor]]:
"""Run the transformer encoder.
Args:
x:
The model input. Its shape is (N, T, C).
supervisions:
Supervision in lhotse format.
See https://github.com/lhotse-speech/lhotse/blob/master/lhotse/dataset/speech_recognition.py#L32 # noqa
CAUTION: It contains length information, i.e., start and number of
frames, before subsampling
It is read directly from the batch, without any sorting. It is used
to compute the encoder padding mask, which is used as memory key
padding mask for the decoder.
Returns:
Return a tuple with two tensors:
- The encoder output, with shape (T, N, C)
- encoder padding mask, with shape (N, T).
The mask is None if `supervisions` is None.
It is used as memory key padding mask in the decoder.
"""
x = self.encoder_embed(x)
x = self.encoder_pos(x)
x = x.permute(1, 0, 2) # (N, T, C) -> (T, N, C)
mask = encoder_padding_mask(x.size(0), supervisions)
mask = mask.to(x.device) if mask is not None else None
x = self.encoder(x, src_key_padding_mask=mask) # (T, N, C)
return x, mask
def ctc_output(self, x: torch.Tensor) -> torch.Tensor:
"""
Args:
x:
The output tensor from the transformer encoder.
Its shape is (T, N, C)
Returns:
Return a tensor that can be used for CTC decoding.
Its shape is (N, T, C)
"""
x = self.encoder_output_layer(x)
x = x.permute(1, 0, 2) # (T, N, C) ->(N, T, C)
x = nn.functional.log_softmax(x, dim=-1) # (N, T, C)
return x
@torch.jit.export
def decoder_forward(
self,
memory: torch.Tensor,
memory_key_padding_mask: torch.Tensor,
token_ids: List[List[int]],
sos_id: int,
eos_id: int,
) -> torch.Tensor:
"""
Args:
memory:
It's the output of the encoder with shape (T, N, C)
memory_key_padding_mask:
The padding mask from the encoder.
token_ids:
A list-of-list IDs. Each sublist contains IDs for an utterance.
The IDs can be either phone IDs or word piece IDs.
sos_id:
sos token id
eos_id:
eos token id
Returns:
A scalar, the **sum** of label smoothing loss over utterances
in the batch without any normalization.
"""
ys_in = add_sos(token_ids, sos_id=sos_id)
ys_in = [torch.tensor(y) for y in ys_in]
ys_in_pad = pad_sequence(ys_in, batch_first=True, padding_value=float(eos_id))
ys_out = add_eos(token_ids, eos_id=eos_id)
ys_out = [torch.tensor(y) for y in ys_out]
ys_out_pad = pad_sequence(ys_out, batch_first=True, padding_value=float(-1))
device = memory.device
ys_in_pad = ys_in_pad.to(device)
ys_out_pad = ys_out_pad.to(device)
tgt_mask = generate_square_subsequent_mask(ys_in_pad.shape[-1]).to(device)
tgt_key_padding_mask = decoder_padding_mask(ys_in_pad, ignore_id=eos_id)
# TODO: Use length information to create the decoder padding mask
# We set the first column to False since the first column in ys_in_pad
# contains sos_id, which is the same as eos_id in our current setting.
tgt_key_padding_mask[:, 0] = False
tgt = self.decoder_embed(ys_in_pad) # (N, T) -> (N, T, C)
tgt = self.decoder_pos(tgt)
tgt = tgt.permute(1, 0, 2) # (N, T, C) -> (T, N, C)
pred_pad = self.decoder(
tgt=tgt,
memory=memory,
tgt_mask=tgt_mask,
tgt_key_padding_mask=tgt_key_padding_mask,
memory_key_padding_mask=memory_key_padding_mask,
) # (T, N, C)
pred_pad = pred_pad.permute(1, 0, 2) # (T, N, C) -> (N, T, C)
pred_pad = self.decoder_output_layer(pred_pad) # (N, T, C)
decoder_loss = self.decoder_criterion(pred_pad, ys_out_pad)
return decoder_loss
@torch.jit.export
def decoder_nll(
self,
memory: torch.Tensor,
memory_key_padding_mask: torch.Tensor,
token_ids: List[torch.Tensor],
sos_id: int,
eos_id: int,
) -> torch.Tensor:
"""
Args:
memory:
It's the output of the encoder with shape (T, N, C)
memory_key_padding_mask:
The padding mask from the encoder.
token_ids:
A list-of-list IDs (e.g., word piece IDs).
Each sublist represents an utterance.
sos_id:
The token ID for SOS.
eos_id:
The token ID for EOS.
Returns:
A 2-D tensor of shape (len(token_ids), max_token_length)
representing the cross entropy loss (i.e., negative log-likelihood).
"""
# The common part between this function and decoder_forward could be
# extracted as a separate function.
if isinstance(token_ids[0], torch.Tensor):
# This branch is executed by torchscript in C++.
# See https://github.com/k2-fsa/k2/pull/870
# https://github.com/k2-fsa/k2/blob/3c1c18400060415b141ccea0115fd4bf0ad6234e/k2/torch/bin/attention_rescore.cu#L286
token_ids = [tolist(t) for t in token_ids]
ys_in = add_sos(token_ids, sos_id=sos_id)
ys_in = [torch.tensor(y) for y in ys_in]
ys_in_pad = pad_sequence(ys_in, batch_first=True, padding_value=float(eos_id))
ys_out = add_eos(token_ids, eos_id=eos_id)
ys_out = [torch.tensor(y) for y in ys_out]
ys_out_pad = pad_sequence(ys_out, batch_first=True, padding_value=float(-1))
device = memory.device
ys_in_pad = ys_in_pad.to(device, dtype=torch.int64)
ys_out_pad = ys_out_pad.to(device, dtype=torch.int64)
tgt_mask = generate_square_subsequent_mask(ys_in_pad.shape[-1]).to(device)
tgt_key_padding_mask = decoder_padding_mask(ys_in_pad, ignore_id=eos_id)
# TODO: Use length information to create the decoder padding mask
# We set the first column to False since the first column in ys_in_pad
# contains sos_id, which is the same as eos_id in our current setting.
tgt_key_padding_mask[:, 0] = False
tgt = self.decoder_embed(ys_in_pad) # (B, T) -> (B, T, F)
tgt = self.decoder_pos(tgt)
tgt = tgt.permute(1, 0, 2) # (B, T, F) -> (T, B, F)
pred_pad = self.decoder(
tgt=tgt,
memory=memory,
tgt_mask=tgt_mask,
tgt_key_padding_mask=tgt_key_padding_mask,
memory_key_padding_mask=memory_key_padding_mask,
) # (T, B, F)
pred_pad = pred_pad.permute(1, 0, 2) # (T, B, F) -> (B, T, F)
pred_pad = self.decoder_output_layer(pred_pad) # (B, T, F)
# nll: negative log-likelihood
nll = torch.nn.functional.cross_entropy(
pred_pad.view(-1, self.decoder_num_class),
ys_out_pad.view(-1),
ignore_index=-1,
reduction="none",
)
nll = nll.view(pred_pad.shape[0], -1)
return nll
class TransformerEncoderLayer(nn.Module):
"""
Modified from torch.nn.TransformerEncoderLayer.
Add support of normalize_before,
i.e., use layer_norm before the first block.
Args:
d_model:
the number of expected features in the input (required).
nhead:
the number of heads in the multiheadattention models (required).
dim_feedforward:
the dimension of the feedforward network model (default=2048).
dropout:
the dropout value (default=0.1).
activation:
the activation function of intermediate layer, relu or
gelu (default=relu).
normalize_before:
whether to use layer_norm before the first block.
Examples::
>>> encoder_layer = TransformerEncoderLayer(d_model=512, nhead=8)
>>> src = torch.rand(10, 32, 512)
>>> out = encoder_layer(src)
"""
def __init__(
self,
d_model: int,
nhead: int,
dim_feedforward: int = 2048,
dropout: float = 0.1,
activation: str = "relu",
normalize_before: bool = True,
) -> None:
super(TransformerEncoderLayer, self).__init__()
self.self_attn = nn.MultiheadAttention(d_model, nhead, dropout=0.0)
# Implementation of Feedforward model
self.linear1 = nn.Linear(d_model, dim_feedforward)
self.dropout = nn.Dropout(dropout)
self.linear2 = nn.Linear(dim_feedforward, d_model)
self.norm1 = nn.LayerNorm(d_model)
self.norm2 = nn.LayerNorm(d_model)
self.dropout1 = nn.Dropout(dropout)
self.dropout2 = nn.Dropout(dropout)
self.activation = _get_activation_fn(activation)
self.normalize_before = normalize_before
def __setstate__(self, state):
if "activation" not in state:
state["activation"] = nn.functional.relu
super(TransformerEncoderLayer, self).__setstate__(state)
def forward(
self,
src: torch.Tensor,
src_mask: Optional[torch.Tensor] = None,
src_key_padding_mask: Optional[torch.Tensor] = None,
) -> torch.Tensor:
"""
Pass the input through the encoder layer.
Args:
src: the sequence to the encoder layer (required).
src_mask: the mask for the src sequence (optional).
src_key_padding_mask: the mask for the src keys per batch (optional)
Shape:
src: (S, N, E).
src_mask: (S, S).
src_key_padding_mask: (N, S).
S is the source sequence length, T is the target sequence length,
N is the batch size, E is the feature number
"""
residual = src
if self.normalize_before:
src = self.norm1(src)
src2 = self.self_attn(
src,
src,
src,
attn_mask=src_mask,
key_padding_mask=src_key_padding_mask,
)[0]
src = residual + self.dropout1(src2)
if not self.normalize_before:
src = self.norm1(src)
residual = src
if self.normalize_before:
src = self.norm2(src)
src2 = self.linear2(self.dropout(self.activation(self.linear1(src))))
src = residual + self.dropout2(src2)
if not self.normalize_before:
src = self.norm2(src)
return src
class TransformerDecoderLayer(nn.Module):
"""
Modified from torch.nn.TransformerDecoderLayer.
Add support of normalize_before,
i.e., use layer_norm before the first block.
Args:
d_model:
the number of expected features in the input (required).
nhead:
the number of heads in the multiheadattention models (required).
dim_feedforward:
the dimension of the feedforward network model (default=2048).
dropout:
the dropout value (default=0.1).
activation:
the activation function of intermediate layer, relu or
gelu (default=relu).
Examples::
>>> decoder_layer = nn.TransformerDecoderLayer(d_model=512, nhead=8)
>>> memory = torch.rand(10, 32, 512)
>>> tgt = torch.rand(20, 32, 512)
>>> out = decoder_layer(tgt, memory)
"""
def __init__(
self,
d_model: int,
nhead: int,
dim_feedforward: int = 2048,
dropout: float = 0.1,
activation: str = "relu",
normalize_before: bool = True,
) -> None:
super(TransformerDecoderLayer, self).__init__()
self.self_attn = nn.MultiheadAttention(d_model, nhead, dropout=0.0)
self.src_attn = nn.MultiheadAttention(d_model, nhead, dropout=0.0)
# Implementation of Feedforward model
self.linear1 = nn.Linear(d_model, dim_feedforward)
self.dropout = nn.Dropout(dropout)
self.linear2 = nn.Linear(dim_feedforward, d_model)
self.norm1 = nn.LayerNorm(d_model)
self.norm2 = nn.LayerNorm(d_model)
self.norm3 = nn.LayerNorm(d_model)
self.dropout1 = nn.Dropout(dropout)
self.dropout2 = nn.Dropout(dropout)
self.dropout3 = nn.Dropout(dropout)
self.activation = _get_activation_fn(activation)
self.normalize_before = normalize_before
def __setstate__(self, state):
if "activation" not in state:
state["activation"] = nn.functional.relu
super(TransformerDecoderLayer, self).__setstate__(state)
def forward(
self,
tgt: torch.Tensor,
memory: torch.Tensor,
tgt_mask: Optional[torch.Tensor] = None,
memory_mask: Optional[torch.Tensor] = None,
tgt_key_padding_mask: Optional[torch.Tensor] = None,
memory_key_padding_mask: Optional[torch.Tensor] = None,
) -> torch.Tensor:
"""Pass the inputs (and mask) through the decoder layer.
Args:
tgt:
the sequence to the decoder layer (required).
memory:
the sequence from the last layer of the encoder (required).
tgt_mask:
the mask for the tgt sequence (optional).
memory_mask:
the mask for the memory sequence (optional).
tgt_key_padding_mask:
the mask for the tgt keys per batch (optional).
memory_key_padding_mask:
the mask for the memory keys per batch (optional).
Shape:
tgt: (T, N, E).
memory: (S, N, E).
tgt_mask: (T, T).
memory_mask: (T, S).
tgt_key_padding_mask: (N, T).
memory_key_padding_mask: (N, S).
S is the source sequence length, T is the target sequence length,
N is the batch size, E is the feature number
"""
residual = tgt
if self.normalize_before:
tgt = self.norm1(tgt)
tgt2 = self.self_attn(
tgt,
tgt,
tgt,
attn_mask=tgt_mask,
key_padding_mask=tgt_key_padding_mask,
)[0]
tgt = residual + self.dropout1(tgt2)
if not self.normalize_before:
tgt = self.norm1(tgt)
residual = tgt
if self.normalize_before:
tgt = self.norm2(tgt)
tgt2 = self.src_attn(
tgt,
memory,
memory,
attn_mask=memory_mask,
key_padding_mask=memory_key_padding_mask,
)[0]
tgt = residual + self.dropout2(tgt2)
if not self.normalize_before:
tgt = self.norm2(tgt)
residual = tgt
if self.normalize_before:
tgt = self.norm3(tgt)
tgt2 = self.linear2(self.dropout(self.activation(self.linear1(tgt))))
tgt = residual + self.dropout3(tgt2)
if not self.normalize_before:
tgt = self.norm3(tgt)
return tgt
def _get_activation_fn(activation: str):
if activation == "relu":
return nn.functional.relu
elif activation == "gelu":
return nn.functional.gelu
raise RuntimeError("activation should be relu/gelu, not {}".format(activation))
class PositionalEncoding(nn.Module):
"""This class implements the positional encoding
proposed in the following paper:
- Attention Is All You Need: https://arxiv.org/pdf/1706.03762.pdf
PE(pos, 2i) = sin(pos / (10000^(2i/d_modle))
PE(pos, 2i+1) = cos(pos / (10000^(2i/d_modle))
Note::
1 / (10000^(2i/d_model)) = exp(-log(10000^(2i/d_model)))
= exp(-1* 2i / d_model * log(100000))
= exp(2i * -(log(10000) / d_model))
"""
def __init__(self, d_model: int, dropout: float = 0.1) -> None:
"""
Args:
d_model:
Embedding dimension.
dropout:
Dropout probability to be applied to the output of this module.
"""
super().__init__()
self.d_model = d_model
self.xscale = math.sqrt(self.d_model)
self.dropout = nn.Dropout(p=dropout)
# not doing: self.pe = None because of errors thrown by torchscript
self.pe = torch.zeros(1, 0, self.d_model, dtype=torch.float32)
def extend_pe(self, x: torch.Tensor) -> None:
"""Extend the time t in the positional encoding if required.
The shape of `self.pe` is (1, T1, d_model). The shape of the input x
is (N, T, d_model). If T > T1, then we change the shape of self.pe
to (N, T, d_model). Otherwise, nothing is done.
Args:
x:
It is a tensor of shape (N, T, C).
Returns:
Return None.
"""
if self.pe is not None:
if self.pe.size(1) >= x.size(1):
self.pe = self.pe.to(dtype=x.dtype, device=x.device)
return
pe = torch.zeros(x.size(1), self.d_model, dtype=torch.float32)
position = torch.arange(0, x.size(1), dtype=torch.float32).unsqueeze(1)
div_term = torch.exp(
torch.arange(0, self.d_model, 2, dtype=torch.float32)
* -(math.log(10000.0) / self.d_model)
)
pe[:, 0::2] = torch.sin(position * div_term)
pe[:, 1::2] = torch.cos(position * div_term)
pe = pe.unsqueeze(0)
# Now pe is of shape (1, T, d_model), where T is x.size(1)
self.pe = pe.to(device=x.device, dtype=x.dtype)
def forward(self, x: torch.Tensor) -> torch.Tensor:
"""
Add positional encoding.
Args:
x:
Its shape is (N, T, C)
Returns:
Return a tensor of shape (N, T, C)
"""
self.extend_pe(x)
x = x * self.xscale + self.pe[:, : x.size(1), :]
return self.dropout(x)
class Noam(object):
"""
Implements Noam optimizer.
Proposed in
"Attention Is All You Need", https://arxiv.org/pdf/1706.03762.pdf
Modified from
https://github.com/espnet/espnet/blob/master/espnet/nets/pytorch_backend/transformer/optimizer.py # noqa
Args:
params:
iterable of parameters to optimize or dicts defining parameter groups
model_size:
attention dimension of the transformer model
factor:
learning rate factor
warm_step:
warmup steps
"""
def __init__(
self,
params,
model_size: int = 256,
factor: float = 10.0,
warm_step: int = 25000,
weight_decay=0,
) -> None:
"""Construct an Noam object."""
self.optimizer = torch.optim.Adam(
params, lr=0, betas=(0.9, 0.98), eps=1e-9, weight_decay=weight_decay
)
self._step = 0
self.warmup = warm_step
self.factor = factor
self.model_size = model_size
self._rate = 0
@property
def param_groups(self):
"""Return param_groups."""
return self.optimizer.param_groups
def step(self):
"""Update parameters and rate."""
self._step += 1
rate = self.rate()
for p in self.optimizer.param_groups:
p["lr"] = rate
self._rate = rate
self.optimizer.step()
def rate(self, step=None):
"""Implement `lrate` above."""
if step is None:
step = self._step
return (
self.factor
* self.model_size ** (-0.5)
* min(step ** (-0.5), step * self.warmup ** (-1.5))
)
def zero_grad(self):
"""Reset gradient."""
self.optimizer.zero_grad()
def state_dict(self):
"""Return state_dict."""
return {
"_step": self._step,
"warmup": self.warmup,
"factor": self.factor,
"model_size": self.model_size,
"_rate": self._rate,
"optimizer": self.optimizer.state_dict(),
}
def load_state_dict(self, state_dict):
"""Load state_dict."""
for key, value in state_dict.items():
if key == "optimizer":
self.optimizer.load_state_dict(state_dict["optimizer"])
else:
setattr(self, key, value)
def encoder_padding_mask(
max_len: int, supervisions: Optional[Supervisions] = None
) -> Optional[torch.Tensor]:
"""Make mask tensor containing indexes of padded part.
TODO::
This function **assumes** that the model uses
a subsampling factor of 4. We should remove that
assumption later.
Args:
max_len:
Maximum length of input features.
CAUTION: It is the length after subsampling.
supervisions:
Supervision in lhotse format.
See https://github.com/lhotse-speech/lhotse/blob/master/lhotse/dataset/speech_recognition.py#L32 # noqa
(CAUTION: It contains length information, i.e., start and number of
frames, before subsampling)
Returns:
Tensor: Mask tensor of dimension (batch_size, input_length),
True denote the masked indices.
"""
if supervisions is None:
return None
supervision_segments = torch.stack(
(
supervisions["sequence_idx"],
supervisions["start_frame"],
supervisions["num_frames"],
),
1,
).to(torch.int32)
lengths = [0 for _ in range(int(supervision_segments[:, 0].max().item()) + 1)]
for idx in range(supervision_segments.size(0)):
# Note: TorchScript doesn't allow to unpack tensors as tuples
sequence_idx = supervision_segments[idx, 0].item()
start_frame = supervision_segments[idx, 1].item()
num_frames = supervision_segments[idx, 2].item()
lengths[sequence_idx] = start_frame + num_frames
lengths = [((i - 1) // 2 - 1) // 2 for i in lengths]
bs = int(len(lengths))
seq_range = torch.arange(0, max_len, dtype=torch.int64)
seq_range_expand = seq_range.unsqueeze(0).expand(bs, max_len)
# Note: TorchScript doesn't implement Tensor.new()
seq_length_expand = torch.tensor(
lengths, device=seq_range_expand.device, dtype=seq_range_expand.dtype
).unsqueeze(-1)
mask = seq_range_expand >= seq_length_expand
return mask
def decoder_padding_mask(ys_pad: torch.Tensor, ignore_id: int = -1) -> torch.Tensor:
"""Generate a length mask for input.
The masked position are filled with True,
Unmasked positions are filled with False.
Args:
ys_pad:
padded tensor of dimension (batch_size, input_length).
ignore_id:
the ignored number (the padding number) in ys_pad
Returns:
Tensor:
a bool tensor of the same shape as the input tensor.
"""
ys_mask = ys_pad == ignore_id
return ys_mask
def generate_square_subsequent_mask(sz: int) -> torch.Tensor:
"""Generate a square mask for the sequence. The masked positions are
filled with float('-inf'). Unmasked positions are filled with float(0.0).
The mask can be used for masked self-attention.
For instance, if sz is 3, it returns::
tensor([[0., -inf, -inf],
[0., 0., -inf],
[0., 0., 0]])
Args:
sz: mask size
Returns:
A square mask of dimension (sz, sz)
"""
mask = (torch.triu(torch.ones(sz, sz)) == 1).transpose(0, 1)
mask = (
mask.float()
.masked_fill(mask == 0, float("-inf"))
.masked_fill(mask == 1, float(0.0))
)
return mask
def add_sos(token_ids: List[List[int]], sos_id: int) -> List[List[int]]:
"""Prepend sos_id to each utterance.
Args:
token_ids:
A list-of-list of token IDs. Each sublist contains
token IDs (e.g., word piece IDs) of an utterance.
sos_id:
The ID of the SOS token.
Return:
Return a new list-of-list, where each sublist starts
with SOS ID.
"""
return [[sos_id] + utt for utt in token_ids]
def add_eos(token_ids: List[List[int]], eos_id: int) -> List[List[int]]:
"""Append eos_id to each utterance.
Args:
token_ids:
A list-of-list of token IDs. Each sublist contains
token IDs (e.g., word piece IDs) of an utterance.
eos_id:
The ID of the EOS token.
Return:
Return a new list-of-list, where each sublist ends
with EOS ID.
"""
return [utt + [eos_id] for utt in token_ids]
def tolist(t: torch.Tensor) -> List[int]:
"""Used by jit"""
return torch.jit.annotate(List[int], t.tolist())

View File

@ -0,0 +1 @@
../../../librispeech/ASR/conformer_ctc/transformer.py