diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index b9c0956f0..baa9c1727 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -103,8 +103,10 @@ jobs:
cd egs/librispeech/ASR/conformer_ctc
pytest -v -s
- cd ..
- pytest -v -s ./transducer
+ if [[ ${{ matrix.torchaudio }} == "0.10.0" ]]; then
+ cd ../transducer
+ pytest -v -s
+ fi
- name: Run tests
if: startsWith(matrix.os, 'macos')
@@ -120,5 +122,7 @@ jobs:
cd egs/librispeech/ASR/conformer_ctc
pytest -v -s
- cd ..
- pytest -v -s ./transducer
+ if [[ ${{ matrix.torchaudio }} == "0.10.0" ]]; then
+ cd ../transducer
+ pytest -v -s
+ fi
diff --git a/.gitignore b/.gitignore
index 31da5ed3e..870d3cea3 100644
--- a/.gitignore
+++ b/.gitignore
@@ -8,3 +8,4 @@ exp*/
download
*.bak
*-bak
+*bak.py
diff --git a/README.md b/README.md
index 707ed09d0..23389d483 100644
--- a/README.md
+++ b/README.md
@@ -34,8 +34,11 @@ We do provide a Colab notebook for this recipe.
### LibriSpeech
-We provide two models for this recipe: [conformer CTC model][LibriSpeech_conformer_ctc]
-and [TDNN LSTM CTC model][LibriSpeech_tdnn_lstm_ctc].
+We provide 3 models for this recipe:
+
+- [conformer CTC model][LibriSpeech_conformer_ctc]
+- [TDNN LSTM CTC model][LibriSpeech_tdnn_lstm_ctc]
+- [RNN-T Conformer model][LibriSpeech_transducer]
#### Conformer CTC Model
@@ -58,6 +61,20 @@ The WER for this model is:
We provide a Colab notebook to run a pre-trained TDNN LSTM CTC model: [](https://colab.research.google.com/drive/1kNmDXNMwREi0rZGAOIAOJo93REBuOTcd?usp=sharing)
+
+#### RNN-T Conformer model
+
+Using Conformer as encoder.
+
+The best WER with greedy search is:
+
+| | test-clean | test-other |
+|-----|------------|------------|
+| WER | 3.16 | 7.71 |
+
+We provide a Colab notebook to run a pre-trained RNN-T conformer model: [](https://colab.research.google.com/drive/1_u6yK9jDkPwG_NLrZMN2XK7Aeq4suMO2?usp=sharing)
+
+
### Aishell
We provide two models for this recipe: [conformer CTC model][Aishell_conformer_ctc]
@@ -125,6 +142,7 @@ Please see: [
+
+#### 2021-12-17
+
+RNN-T + Conformer encoder
+
+The best WER is
+
+| | test-clean | test-other |
+|-----|------------|------------|
+| WER | 3.16 | 7.71 |
+
+using `--epoch 26 --avg 12` during decoding with greedy search.
+
+The training command to reproduce the above WER is:
+
+```
+export CUDA_VISIBLE_DEVICES="0,1,2,3"
+
+./transducer/train.py \
+ --world-size 4 \
+ --num-epochs 30 \
+ --start-epoch 0 \
+ --exp-dir transducer/exp-lr-2.5-full \
+ --full-libri 1 \
+ --max-duration 250 \
+ --lr-factor 2.5
+```
+
+The decoding command is:
+
+```
+epoch=26
+avg=12
+
+./transducer/decode.py \
+ --epoch $epoch \
+ --avg $avg \
+ --exp-dir transducer/exp-lr-2.5-full \
+ --bpe-model ./data/lang_bpe_500/bpe.model \
+ --max-duration 100
+```
+
+You can find the tensorboard log at:
+
+
### LibriSpeech BPE training results (Conformer-CTC)
#### 2021-11-09
diff --git a/egs/librispeech/ASR/conformer_ctc/decode.py b/egs/librispeech/ASR/conformer_ctc/decode.py
index bcd363df3..177e33a6e 100755
--- a/egs/librispeech/ASR/conformer_ctc/decode.py
+++ b/egs/librispeech/ASR/conformer_ctc/decode.py
@@ -428,8 +428,6 @@ def decode_dataset(
The first is the reference transcript, and the second is the
predicted result.
"""
- results = []
-
num_cuts = 0
try:
diff --git a/egs/librispeech/ASR/local/display_manifest_statistics.py b/egs/librispeech/ASR/local/display_manifest_statistics.py
new file mode 100755
index 000000000..15bd206fa
--- /dev/null
+++ b/egs/librispeech/ASR/local/display_manifest_statistics.py
@@ -0,0 +1,215 @@
+#!/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.
+
+"""
+This file displays duration statistics of utterances in a manifest.
+You can use the displayed value to choose minimum/maximum duration
+to remove short and long utterances during the training.
+
+See the function `remove_short_and_long_utt()` in transducer/train.py
+for usage.
+"""
+
+
+from lhotse import load_manifest
+
+
+def main():
+ path = "./data/fbank/cuts_train-clean-100.json.gz"
+ path = "./data/fbank/cuts_train-clean-360.json.gz"
+ path = "./data/fbank/cuts_train-other-500.json.gz"
+ path = "./data/fbank/cuts_dev-clean.json.gz"
+ path = "./data/fbank/cuts_dev-other.json.gz"
+ path = "./data/fbank/cuts_test-clean.json.gz"
+ path = "./data/fbank/cuts_test-other.json.gz"
+
+ cuts = load_manifest(path)
+ cuts.describe()
+
+
+if __name__ == "__main__":
+ main()
+
+"""
+## train-clean-100
+Cuts count: 85617
+Total duration (hours): 303.8
+Speech duration (hours): 303.8 (100.0%)
+***
+Duration statistics (seconds):
+mean 12.8
+std 3.8
+min 1.3
+0.1% 1.9
+0.5% 2.2
+1% 2.5
+5% 4.2
+10% 6.4
+25% 11.4
+50% 13.8
+75% 15.3
+90% 16.7
+95% 17.3
+99% 18.1
+99.5% 18.4
+99.9% 18.8
+max 27.2
+
+## train-clean-360
+Cuts count: 312042
+Total duration (hours): 1098.2
+Speech duration (hours): 1098.2 (100.0%)
+***
+Duration statistics (seconds):
+mean 12.7
+std 3.8
+min 1.0
+0.1% 1.8
+0.5% 2.2
+1% 2.5
+5% 4.2
+10% 6.2
+25% 11.2
+50% 13.7
+75% 15.3
+90% 16.6
+95% 17.3
+99% 18.1
+99.5% 18.4
+99.9% 18.8
+max 33.0
+
+## train-other 500
+Cuts count: 446064
+Total duration (hours): 1500.6
+Speech duration (hours): 1500.6 (100.0%)
+***
+Duration statistics (seconds):
+mean 12.1
+std 4.2
+min 0.8
+0.1% 1.7
+0.5% 2.1
+1% 2.3
+5% 3.5
+10% 5.0
+25% 9.8
+50% 13.4
+75% 15.1
+90% 16.5
+95% 17.2
+99% 18.1
+99.5% 18.4
+99.9% 18.9
+max 31.0
+
+## dev-clean
+Cuts count: 2703
+Total duration (hours): 5.4
+Speech duration (hours): 5.4 (100.0%)
+***
+Duration statistics (seconds):
+mean 7.2
+std 4.7
+min 1.4
+0.1% 1.6
+0.5% 1.8
+1% 1.9
+5% 2.4
+10% 2.7
+25% 3.8
+50% 5.9
+75% 9.3
+90% 13.3
+95% 16.4
+99% 23.8
+99.5% 28.5
+99.9% 32.3
+max 32.6
+
+## dev-other
+Cuts count: 2864
+Total duration (hours): 5.1
+Speech duration (hours): 5.1 (100.0%)
+***
+Duration statistics (seconds):
+mean 6.4
+std 4.3
+min 1.1
+0.1% 1.3
+0.5% 1.7
+1% 1.8
+5% 2.2
+10% 2.6
+25% 3.5
+50% 5.3
+75% 7.9
+90% 12.0
+95% 15.0
+99% 22.2
+99.5% 27.1
+99.9% 32.4
+max 35.2
+
+## test-clean
+Cuts count: 2620
+Total duration (hours): 5.4
+Speech duration (hours): 5.4 (100.0%)
+***
+Duration statistics (seconds):
+mean 7.4
+std 5.2
+min 1.3
+0.1% 1.6
+0.5% 1.8
+1% 2.0
+5% 2.3
+10% 2.7
+25% 3.7
+50% 5.8
+75% 9.6
+90% 14.6
+95% 17.8
+99% 25.5
+99.5% 28.4
+99.9% 32.8
+max 35.0
+
+## test-other
+Cuts count: 2939
+Total duration (hours): 5.3
+Speech duration (hours): 5.3 (100.0%)
+***
+Duration statistics (seconds):
+mean 6.5
+std 4.4
+min 1.2
+0.1% 1.5
+0.5% 1.8
+1% 1.9
+5% 2.3
+10% 2.6
+25% 3.4
+50% 5.2
+75% 8.2
+90% 12.6
+95% 15.8
+99% 21.4
+99.5% 23.8
+99.9% 33.5
+max 34.5
+"""
diff --git a/egs/librispeech/ASR/transducer/README.md b/egs/librispeech/ASR/transducer/README.md
new file mode 100644
index 000000000..a5b067f64
--- /dev/null
+++ b/egs/librispeech/ASR/transducer/README.md
@@ -0,0 +1,19 @@
+## Introduction
+
+The encoder consists of Conformer layers in this folder. You can use the
+following command to start the training:
+
+```bash
+cd egs/librispeech/ASR
+
+export CUDA_VISIBLE_DEVICES="0,1,2,3"
+
+./transducer/train.py \
+ --world-size 4 \
+ --num-epochs 30 \
+ --start-epoch 0 \
+ --exp-dir transducer/exp \
+ --full-libri 1 \
+ --max-duration 250 \
+ --lr-factor 2.5
+```
diff --git a/egs/librispeech/ASR/transducer/asr_datamodule.py b/egs/librispeech/ASR/transducer/asr_datamodule.py
new file mode 120000
index 000000000..fa1b8cca3
--- /dev/null
+++ b/egs/librispeech/ASR/transducer/asr_datamodule.py
@@ -0,0 +1 @@
+../tdnn_lstm_ctc/asr_datamodule.py
\ No newline at end of file
diff --git a/egs/librispeech/ASR/transducer/beam_search.py b/egs/librispeech/ASR/transducer/beam_search.py
new file mode 100644
index 000000000..013e065be
--- /dev/null
+++ b/egs/librispeech/ASR/transducer/beam_search.py
@@ -0,0 +1,212 @@
+# 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 dataclasses import dataclass
+from typing import Dict, List, Optional, Tuple
+
+import torch
+from model import Transducer
+
+
+def greedy_search(model: Transducer, encoder_out: torch.Tensor) -> List[int]:
+ """
+ Args:
+ model:
+ An instance of `Transducer`.
+ encoder_out:
+ A tensor of shape (N, T, C) from the encoder. Support only N==1 for now.
+ Returns:
+ Return the decoded result.
+ """
+ assert encoder_out.ndim == 3
+
+ # support only batch_size == 1 for now
+ assert encoder_out.size(0) == 1, encoder_out.size(0)
+ blank_id = model.decoder.blank_id
+ device = model.device
+
+ sos = torch.tensor([blank_id], device=device).reshape(1, 1)
+ decoder_out, (h, c) = model.decoder(sos)
+ T = encoder_out.size(1)
+ t = 0
+ hyp = []
+ max_u = 1000 # terminate after this number of steps
+ u = 0
+
+ while t < T and u < max_u:
+ # fmt: off
+ current_encoder_out = encoder_out[:, t:t+1, :]
+ # fmt: on
+ logits = model.joiner(current_encoder_out, decoder_out)
+ # logits is (1, 1, 1, vocab_size)
+
+ log_prob = logits.log_softmax(dim=-1)
+ # log_prob is (1, 1, 1, vocab_size)
+ # TODO: Use logits.argmax()
+ y = log_prob.argmax()
+ if y != blank_id:
+ hyp.append(y.item())
+ y = y.reshape(1, 1)
+ decoder_out, (h, c) = model.decoder(y, (h, c))
+ u += 1
+ else:
+ t += 1
+
+ return hyp
+
+
+@dataclass
+class Hypothesis:
+ ys: List[int] # the predicted sequences so far
+ log_prob: float # The log prob of ys
+
+ # Optional decoder state. We assume it is LSTM for now,
+ # so the state is a tuple (h, c)
+ decoder_state: Optional[Tuple[torch.Tensor, torch.Tensor]] = None
+
+
+def beam_search(
+ model: Transducer,
+ encoder_out: torch.Tensor,
+ beam: int = 5,
+) -> List[int]:
+ """
+ It implements Algorithm 1 in https://arxiv.org/pdf/1211.3711.pdf
+
+ espnet/nets/beam_search_transducer.py#L247 is used as a reference.
+
+ Args:
+ model:
+ An instance of `Transducer`.
+ encoder_out:
+ A tensor of shape (N, T, C) from the encoder. Support only N==1 for now.
+ beam:
+ Beam size.
+ Returns:
+ Return the decoded result.
+ """
+ assert encoder_out.ndim == 3
+
+ # support only batch_size == 1 for now
+ assert encoder_out.size(0) == 1, encoder_out.size(0)
+ blank_id = model.decoder.blank_id
+ sos_id = model.decoder.sos_id
+ device = model.device
+
+ sos = torch.tensor([blank_id], device=device).reshape(1, 1)
+ decoder_out, (h, c) = model.decoder(sos)
+ T = encoder_out.size(1)
+ t = 0
+ B = [Hypothesis(ys=[blank_id], log_prob=0.0, decoder_state=None)]
+ max_u = 20000 # terminate after this number of steps
+ u = 0
+
+ cache: Dict[
+ str, Tuple[torch.Tensor, Tuple[torch.Tensor, torch.Tensor]]
+ ] = {}
+
+ while t < T and u < max_u:
+ # fmt: off
+ current_encoder_out = encoder_out[:, t:t+1, :]
+ # fmt: on
+ A = B
+ B = []
+ # for hyp in A:
+ # for h in A:
+ # if h.ys == hyp.ys[:-1]:
+ # # update the score of hyp
+ # decoder_input = torch.tensor(
+ # [h.ys[-1]], device=device
+ # ).reshape(1, 1)
+ # decoder_out, _ = model.decoder(
+ # decoder_input, h.decoder_state
+ # )
+ # logits = model.joiner(current_encoder_out, decoder_out)
+ # log_prob = logits.log_softmax(dim=-1)
+ # log_prob = log_prob.squeeze()
+ # hyp.log_prob += h.log_prob + log_prob[hyp.ys[-1]].item()
+
+ while u < max_u:
+ y_star = max(A, key=lambda hyp: hyp.log_prob)
+ A.remove(y_star)
+
+ # Note: y_star.ys is unhashable, i.e., cannot be used
+ # as a key into a dict
+ cached_key = "_".join(map(str, y_star.ys))
+
+ if cached_key not in cache:
+ decoder_input = torch.tensor(
+ [y_star.ys[-1]], device=device
+ ).reshape(1, 1)
+
+ decoder_out, decoder_state = model.decoder(
+ decoder_input,
+ y_star.decoder_state,
+ )
+ cache[cached_key] = (decoder_out, decoder_state)
+ else:
+ decoder_out, decoder_state = cache[cached_key]
+
+ logits = model.joiner(current_encoder_out, decoder_out)
+ log_prob = logits.log_softmax(dim=-1)
+ # log_prob is (1, 1, 1, vocab_size)
+ log_prob = log_prob.squeeze()
+ # Now log_prob is (vocab_size,)
+
+ # If we choose blank here, add the new hypothesis to B.
+ # Otherwise, add the new hypothesis to A
+
+ # First, choose blank
+ skip_log_prob = log_prob[blank_id]
+ new_y_star_log_prob = y_star.log_prob + skip_log_prob.item()
+
+ # ys[:] returns a copy of ys
+ new_y_star = Hypothesis(
+ ys=y_star.ys[:],
+ log_prob=new_y_star_log_prob,
+ # Caution: Use y_star.decoder_state here
+ decoder_state=y_star.decoder_state,
+ )
+ B.append(new_y_star)
+
+ # Second, choose other labels
+ for i, v in enumerate(log_prob.tolist()):
+ if i in (blank_id, sos_id):
+ continue
+ new_ys = y_star.ys + [i]
+ new_log_prob = y_star.log_prob + v
+ new_hyp = Hypothesis(
+ ys=new_ys,
+ log_prob=new_log_prob,
+ decoder_state=decoder_state,
+ )
+ A.append(new_hyp)
+ u += 1
+ # check whether B contains more than "beam" elements more probable
+ # than the most probable in A
+ A_most_probable = max(A, key=lambda hyp: hyp.log_prob)
+ B = sorted(
+ [hyp for hyp in B if hyp.log_prob > A_most_probable.log_prob],
+ key=lambda hyp: hyp.log_prob,
+ reverse=True,
+ )
+ if len(B) >= beam:
+ B = B[:beam]
+ break
+ t += 1
+ best_hyp = max(B, key=lambda hyp: hyp.log_prob / len(hyp.ys[1:]))
+ ys = best_hyp.ys[1:] # [1:] to remove the blank
+ return ys
diff --git a/egs/librispeech/ASR/transducer/conformer.py b/egs/librispeech/ASR/transducer/conformer.py
new file mode 100644
index 000000000..245aaa428
--- /dev/null
+++ b/egs/librispeech/ASR/transducer/conformer.py
@@ -0,0 +1,922 @@
+#!/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
+
+import torch
+from torch import Tensor, nn
+from transformer import Transformer
+
+from icefall.utils import make_pad_mask
+
+
+class Conformer(Transformer):
+ """
+ Args:
+ num_features (int): Number of input features
+ output_dim (int): Number of output dimension
+ 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
+ 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,
+ output_dim: int,
+ subsampling_factor: int = 4,
+ d_model: int = 256,
+ nhead: int = 4,
+ dim_feedforward: int = 2048,
+ num_encoder_layers: int = 12,
+ dropout: float = 0.1,
+ cnn_module_kernel: int = 31,
+ normalize_before: bool = True,
+ vgg_frontend: bool = False,
+ use_feat_batchnorm: bool = False,
+ ) -> None:
+ super(Conformer, self).__init__(
+ num_features=num_features,
+ output_dim=output_dim,
+ subsampling_factor=subsampling_factor,
+ d_model=d_model,
+ nhead=nhead,
+ dim_feedforward=dim_feedforward,
+ num_encoder_layers=num_encoder_layers,
+ dropout=dropout,
+ normalize_before=normalize_before,
+ vgg_frontend=vgg_frontend,
+ use_feat_batchnorm=use_feat_batchnorm,
+ )
+
+ self.encoder_pos = RelPositionalEncoding(d_model, dropout)
+
+ encoder_layer = ConformerEncoderLayer(
+ d_model,
+ nhead,
+ dim_feedforward,
+ dropout,
+ cnn_module_kernel,
+ normalize_before,
+ )
+ 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 forward(
+ self, x: torch.Tensor, x_lens: torch.Tensor
+ ) -> Tuple[torch.Tensor, torch.Tensor]:
+ """
+ Args:
+ x:
+ The input tensor. Its shape is (batch_size, seq_len, feature_dim).
+ x_lens:
+ A tensor of shape (batch_size,) containing the number of frames in
+ `x` before padding.
+ Returns:
+ Return a tuple containing 2 tensors:
+ - logits, its shape is (batch_size, output_seq_len, output_dim)
+ - logit_lens, a tensor of shape (batch_size,) containing the number
+ of frames in `logits` before padding.
+ """
+ if 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)
+
+ x = self.encoder_embed(x)
+ x, pos_emb = self.encoder_pos(x)
+ x = x.permute(1, 0, 2) # (N, T, C) -> (T, N, C)
+
+ # Caution: We assume the subsampling factor is 4!
+ lengths = ((x_lens - 1) // 2 - 1) // 2
+ assert x.size(0) == lengths.max().item()
+ mask = make_pad_mask(lengths)
+
+ x = self.encoder(x, pos_emb, src_key_padding_mask=mask) # (T, N, C)
+
+ if self.normalize_before:
+ x = self.after_norm(x)
+
+ logits = self.encoder_output_layer(x)
+ logits = logits.permute(1, 0, 2) # (T, N, C) ->(N, T, C)
+
+ return logits, lengths
+
+
+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,
+ ) -> 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)
+
+ 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))
+ 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 vecotr 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 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
+ ) -> 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.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,
+ )
+ 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) -> Tensor:
+ """Compute convolution module.
+
+ Args:
+ x: Input tensor (#time, batch, channels).
+
+ 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
+ x = self.depthwise_conv(x)
+ x = self.activation(self.norm(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
diff --git a/egs/librispeech/ASR/transducer/decode.py b/egs/librispeech/ASR/transducer/decode.py
new file mode 100755
index 000000000..80b72a89f
--- /dev/null
+++ b/egs/librispeech/ASR/transducer/decode.py
@@ -0,0 +1,463 @@
+#!/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.
+"""
+Usage:
+(1) greedy search
+./transducer/decode.py \
+ --epoch 14 \
+ --avg 7 \
+ --exp-dir ./transducer/exp \
+ --max-duration 100 \
+ --decoding-method greedy_search
+
+(2) beam search
+./transducer/decode.py \
+ --epoch 14 \
+ --avg 7 \
+ --exp-dir ./transducer/exp \
+ --max-duration 100 \
+ --decoding-method beam_search \
+ --beam-size 8
+"""
+
+
+import argparse
+import logging
+from collections import defaultdict
+from pathlib import Path
+from typing import Dict, List, Tuple
+
+import sentencepiece as spm
+import torch
+import torch.nn as nn
+from asr_datamodule import LibriSpeechAsrDataModule
+from beam_search import beam_search, greedy_search
+from conformer import Conformer
+from decoder import Decoder
+from joiner import Joiner
+from model import Transducer
+
+from icefall.checkpoint import average_checkpoints, load_checkpoint
+from icefall.env import get_env_info
+from icefall.utils import (
+ AttributeDict,
+ setup_logger,
+ store_transcripts,
+ write_error_stats,
+)
+
+
+def get_parser():
+ parser = argparse.ArgumentParser(
+ formatter_class=argparse.ArgumentDefaultsHelpFormatter
+ )
+
+ parser.add_argument(
+ "--epoch",
+ type=int,
+ default=26,
+ help="It specifies the checkpoint to use for decoding."
+ "Note: Epoch counts from 0.",
+ )
+ parser.add_argument(
+ "--avg",
+ type=int,
+ default=12,
+ help="Number of checkpoints to average. Automatically select "
+ "consecutive checkpoints before the checkpoint specified by "
+ "'--epoch'. ",
+ )
+
+ parser.add_argument(
+ "--exp-dir",
+ type=str,
+ default="transducer/exp",
+ help="The experiment dir",
+ )
+
+ parser.add_argument(
+ "--bpe-model",
+ type=str,
+ default="data/lang_bpe_500/bpe.model",
+ help="Path to the BPE model",
+ )
+
+ parser.add_argument(
+ "--decoding-method",
+ type=str,
+ default="greedy_search",
+ help="""Possible values are:
+ - greedy_search
+ - beam_search
+ """,
+ )
+
+ parser.add_argument(
+ "--beam-size",
+ type=int,
+ default=5,
+ help="Used only when --decoding-method is beam_search",
+ )
+
+ return parser
+
+
+def get_params() -> AttributeDict:
+ params = AttributeDict(
+ {
+ # parameters for conformer
+ "feature_dim": 80,
+ "encoder_out_dim": 512,
+ "subsampling_factor": 4,
+ "attention_dim": 512,
+ "nhead": 8,
+ "dim_feedforward": 2048,
+ "num_encoder_layers": 12,
+ "vgg_frontend": False,
+ "use_feat_batchnorm": True,
+ # decoder params
+ "decoder_embedding_dim": 1024,
+ "num_decoder_layers": 4,
+ "decoder_hidden_dim": 512,
+ "env_info": get_env_info(),
+ }
+ )
+ return params
+
+
+def get_encoder_model(params: AttributeDict):
+ # TODO: We can add an option to switch between Conformer and Transformer
+ encoder = Conformer(
+ num_features=params.feature_dim,
+ output_dim=params.encoder_out_dim,
+ subsampling_factor=params.subsampling_factor,
+ d_model=params.attention_dim,
+ nhead=params.nhead,
+ dim_feedforward=params.dim_feedforward,
+ num_encoder_layers=params.num_encoder_layers,
+ vgg_frontend=params.vgg_frontend,
+ use_feat_batchnorm=params.use_feat_batchnorm,
+ )
+ return encoder
+
+
+def get_decoder_model(params: AttributeDict):
+ decoder = Decoder(
+ vocab_size=params.vocab_size,
+ embedding_dim=params.decoder_embedding_dim,
+ blank_id=params.blank_id,
+ sos_id=params.sos_id,
+ num_layers=params.num_decoder_layers,
+ hidden_dim=params.decoder_hidden_dim,
+ output_dim=params.encoder_out_dim,
+ )
+ return decoder
+
+
+def get_joiner_model(params: AttributeDict):
+ joiner = Joiner(
+ input_dim=params.encoder_out_dim,
+ output_dim=params.vocab_size,
+ )
+ return joiner
+
+
+def get_transducer_model(params: AttributeDict):
+ encoder = get_encoder_model(params)
+ decoder = get_decoder_model(params)
+ joiner = get_joiner_model(params)
+
+ model = Transducer(
+ encoder=encoder,
+ decoder=decoder,
+ joiner=joiner,
+ )
+ return model
+
+
+def decode_one_batch(
+ params: AttributeDict,
+ model: nn.Module,
+ sp: spm.SentencePieceProcessor,
+ batch: dict,
+) -> Dict[str, List[List[str]]]:
+ """Decode one batch and return the result in a dict. The dict has the
+ following format:
+
+ - key: It indicates the setting used for decoding. For example,
+ if greedy_search is used, it would be "greedy_search"
+ If beam search with a beam size of 7 is used, it would be
+ "beam_7"
+ - value: It contains the decoding result. `len(value)` equals to
+ batch size. `value[i]` is the decoding result for the i-th
+ utterance in the given batch.
+ Args:
+ params:
+ It's the return value of :func:`get_params`.
+ model:
+ The neural model.
+ sp:
+ The BPE model.
+ batch:
+ It is the return value from iterating
+ `lhotse.dataset.K2SpeechRecognitionDataset`. See its documentation
+ for the format of the `batch`.
+ Returns:
+ Return the decoding result. See above description for the format of
+ the returned dict.
+ """
+ device = model.device
+ feature = batch["inputs"]
+ assert feature.ndim == 3
+
+ feature = feature.to(device)
+ # at entry, feature is (N, T, C)
+
+ supervisions = batch["supervisions"]
+ feature_lens = supervisions["num_frames"].to(device)
+
+ encoder_out, encoder_out_lens = model.encoder(
+ x=feature, x_lens=feature_lens
+ )
+ hyps = []
+ batch_size = encoder_out.size(0)
+
+ for i in range(batch_size):
+ # fmt: off
+ encoder_out_i = encoder_out[i:i+1, :encoder_out_lens[i]]
+ # fmt: on
+ if params.decoding_method == "greedy_search":
+ hyp = greedy_search(model=model, encoder_out=encoder_out_i)
+ elif params.decoding_method == "beam_search":
+ hyp = beam_search(
+ model=model, encoder_out=encoder_out_i, beam=params.beam_size
+ )
+ else:
+ raise ValueError(
+ f"Unsupported decoding method: {params.decoding_method}"
+ )
+ hyps.append(sp.decode(hyp).split())
+
+ if params.decoding_method == "greedy_search":
+ return {"greedy_search": hyps}
+ else:
+ return {f"beam_{params.beam_size}": hyps}
+
+
+def decode_dataset(
+ dl: torch.utils.data.DataLoader,
+ params: AttributeDict,
+ model: nn.Module,
+ sp: spm.SentencePieceProcessor,
+) -> Dict[str, List[Tuple[List[str], List[str]]]]:
+ """Decode dataset.
+
+ Args:
+ dl:
+ PyTorch's dataloader containing the dataset to decode.
+ params:
+ It is returned by :func:`get_params`.
+ model:
+ The neural model.
+ sp:
+ The BPE model.
+ Returns:
+ Return a dict, whose key may be "greedy_search" if greedy search
+ is used, or it may be "beam_7" if beam size of 7 is used.
+ Its value is a list of tuples. Each tuple contains two elements:
+ The first is the reference transcript, and the second is the
+ predicted result.
+ """
+ num_cuts = 0
+
+ try:
+ num_batches = len(dl)
+ except TypeError:
+ num_batches = "?"
+
+ if params.decoding_method == "greedy_search":
+ log_interval = 100
+ else:
+ log_interval = 2
+
+ results = defaultdict(list)
+ for batch_idx, batch in enumerate(dl):
+ texts = batch["supervisions"]["text"]
+
+ hyps_dict = decode_one_batch(
+ params=params,
+ model=model,
+ sp=sp,
+ batch=batch,
+ )
+
+ for name, hyps in hyps_dict.items():
+ this_batch = []
+ assert len(hyps) == len(texts)
+ for hyp_words, ref_text in zip(hyps, texts):
+ ref_words = ref_text.split()
+ this_batch.append((ref_words, hyp_words))
+
+ results[name].extend(this_batch)
+
+ num_cuts += len(texts)
+
+ if batch_idx % log_interval == 0:
+ batch_str = f"{batch_idx}/{num_batches}"
+
+ logging.info(
+ f"batch {batch_str}, cuts processed until now is {num_cuts}"
+ )
+ return results
+
+
+def save_results(
+ params: AttributeDict,
+ test_set_name: str,
+ results_dict: Dict[str, List[Tuple[List[int], List[int]]]],
+):
+ test_set_wers = dict()
+ for key, results in results_dict.items():
+ recog_path = (
+ params.res_dir / f"recogs-{test_set_name}-{key}-{params.suffix}.txt"
+ )
+ store_transcripts(filename=recog_path, texts=results)
+ logging.info(f"The transcripts are stored in {recog_path}")
+
+ # The following prints out WERs, per-word error statistics and aligned
+ # ref/hyp pairs.
+ errs_filename = (
+ params.res_dir / f"errs-{test_set_name}-{key}-{params.suffix}.txt"
+ )
+ with open(errs_filename, "w") as f:
+ wer = write_error_stats(
+ f, f"{test_set_name}-{key}", results, enable_log=True
+ )
+ test_set_wers[key] = wer
+
+ logging.info("Wrote detailed error stats to {}".format(errs_filename))
+
+ test_set_wers = sorted(test_set_wers.items(), key=lambda x: x[1])
+ errs_info = (
+ params.res_dir
+ / f"wer-summary-{test_set_name}-{key}-{params.suffix}.txt"
+ )
+ with open(errs_info, "w") as f:
+ print("settings\tWER", file=f)
+ for key, val in test_set_wers:
+ print("{}\t{}".format(key, val), file=f)
+
+ s = "\nFor {}, WER of different settings are:\n".format(test_set_name)
+ note = "\tbest for {}".format(test_set_name)
+ for key, val in test_set_wers:
+ s += "{}\t{}{}\n".format(key, val, note)
+ note = ""
+ logging.info(s)
+
+
+@torch.no_grad()
+def main():
+ parser = get_parser()
+ LibriSpeechAsrDataModule.add_arguments(parser)
+ args = parser.parse_args()
+ args.exp_dir = Path(args.exp_dir)
+
+ params = get_params()
+ params.update(vars(args))
+
+ assert params.decoding_method in ("greedy_search", "beam_search")
+ params.res_dir = params.exp_dir / params.decoding_method
+
+ params.suffix = f"epoch-{params.epoch}-avg-{params.avg}"
+ if params.decoding_method == "beam_search":
+ params.suffix += f"-beam-{params.beam_size}"
+
+ setup_logger(f"{params.res_dir}/log-decode-{params.suffix}")
+ logging.info("Decoding started")
+
+ device = torch.device("cpu")
+ if torch.cuda.is_available():
+ device = torch.device("cuda", 0)
+
+ logging.info(f"Device: {device}")
+
+ sp = spm.SentencePieceProcessor()
+ sp.load(params.bpe_model)
+
+ # and are defined in local/train_bpe_model.py
+ params.blank_id = sp.piece_to_id("")
+ params.sos_id = sp.piece_to_id("")
+ params.vocab_size = sp.get_piece_size()
+
+ logging.info(params)
+
+ logging.info("About to create model")
+ model = get_transducer_model(params)
+
+ 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.to(device)
+ model.load_state_dict(average_checkpoints(filenames, device=device))
+
+ model.to(device)
+ model.eval()
+ model.device = device
+
+ num_param = sum([p.numel() for p in model.parameters()])
+ logging.info(f"Number of model parameters: {num_param}")
+
+ librispeech = LibriSpeechAsrDataModule(args)
+
+ test_clean_cuts = librispeech.test_clean_cuts()
+ test_other_cuts = librispeech.test_other_cuts()
+
+ test_clean_dl = librispeech.test_dataloaders(test_clean_cuts)
+ test_other_dl = librispeech.test_dataloaders(test_other_cuts)
+
+ test_sets = ["test-clean", "test-other"]
+ test_dl = [test_clean_dl, test_other_dl]
+
+ for test_set, test_dl in zip(test_sets, test_dl):
+ results_dict = decode_dataset(
+ dl=test_dl,
+ params=params,
+ model=model,
+ sp=sp,
+ )
+
+ save_results(
+ params=params,
+ test_set_name=test_set,
+ results_dict=results_dict,
+ )
+
+ logging.info("Done!")
+
+
+torch.set_num_threads(1)
+torch.set_num_interop_threads(1)
+
+if __name__ == "__main__":
+ main()
diff --git a/egs/librispeech/ASR/transducer/decoder.py b/egs/librispeech/ASR/transducer/decoder.py
new file mode 100644
index 000000000..2f6bf4c07
--- /dev/null
+++ b/egs/librispeech/ASR/transducer/decoder.py
@@ -0,0 +1,101 @@
+# 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 typing import Optional, Tuple
+
+import torch
+import torch.nn as nn
+
+
+# TODO(fangjun): Support switching between LSTM and GRU
+class Decoder(nn.Module):
+ def __init__(
+ self,
+ vocab_size: int,
+ embedding_dim: int,
+ blank_id: int,
+ sos_id: int,
+ num_layers: int,
+ hidden_dim: int,
+ output_dim: int,
+ embedding_dropout: float = 0.0,
+ rnn_dropout: float = 0.0,
+ ):
+ """
+ Args:
+ vocab_size:
+ Number of tokens of the modeling unit including blank.
+ embedding_dim:
+ Dimension of the input embedding.
+ blank_id:
+ The ID of the blank symbol.
+ sos_id:
+ The ID of the SOS symbol.
+ num_layers:
+ Number of LSTM layers.
+ hidden_dim:
+ Hidden dimension of LSTM layers.
+ output_dim:
+ Output dimension of the decoder.
+ embedding_dropout:
+ Dropout rate for the embedding layer.
+ rnn_dropout:
+ Dropout for LSTM layers.
+ """
+ super().__init__()
+ self.embedding = nn.Embedding(
+ num_embeddings=vocab_size,
+ embedding_dim=embedding_dim,
+ padding_idx=blank_id,
+ )
+ self.embedding_dropout = nn.Dropout(embedding_dropout)
+ # TODO(fangjun): Use layer normalized LSTM
+ self.rnn = nn.LSTM(
+ input_size=embedding_dim,
+ hidden_size=hidden_dim,
+ num_layers=num_layers,
+ batch_first=True,
+ dropout=rnn_dropout,
+ )
+ self.blank_id = blank_id
+ self.sos_id = sos_id
+ self.output_linear = nn.Linear(hidden_dim, output_dim)
+
+ def forward(
+ self,
+ y: torch.Tensor,
+ states: Optional[Tuple[torch.Tensor, torch.Tensor]] = None,
+ ) -> Tuple[torch.Tensor, Tuple[torch.Tensor, torch.Tensor]]:
+ """
+ Args:
+ y:
+ A 2-D tensor of shape (N, U) with BOS prepended.
+ states:
+ A tuple of two tensors containing the states information of
+ LSTM layers in this decoder.
+ Returns:
+ Return a tuple containing:
+
+ - rnn_output, a tensor of shape (N, U, C)
+ - (h, c), containing the state information for LSTM layers.
+ Both are of shape (num_layers, N, C)
+ """
+ embeding_out = self.embedding(y)
+ embeding_out = self.embedding_dropout(embeding_out)
+ rnn_out, (h, c) = self.rnn(embeding_out, states)
+ out = self.output_linear(rnn_out)
+
+ return out, (h, c)
diff --git a/egs/librispeech/ASR/transducer/encoder_interface.py b/egs/librispeech/ASR/transducer/encoder_interface.py
new file mode 100644
index 000000000..257facce4
--- /dev/null
+++ b/egs/librispeech/ASR/transducer/encoder_interface.py
@@ -0,0 +1,43 @@
+# 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 typing import Tuple
+
+import torch
+import torch.nn as nn
+
+
+class EncoderInterface(nn.Module):
+ def forward(
+ self, x: torch.Tensor, x_lens: torch.Tensor
+ ) -> Tuple[torch.Tensor, torch.Tensor]:
+ """
+ Args:
+ x:
+ A tensor of shape (batch_size, input_seq_len, num_features)
+ containing the input features.
+ x_lens:
+ A tensor of shape (batch_size,) containing the number of frames
+ in `x` before padding.
+ Returns:
+ Return a tuple containing two tensors:
+ - encoder_out, a tensor of (batch_size, out_seq_len, output_dim)
+ containing unnormalized probabilities, i.e., the output of a
+ linear layer.
+ - encoder_out_lens, a tensor of shape (batch_size,) containing
+ the number of frames in `encoder_out` before padding.
+ """
+ raise NotImplementedError("Please implement it in a subclass")
diff --git a/egs/librispeech/ASR/transducer/export.py b/egs/librispeech/ASR/transducer/export.py
new file mode 100755
index 000000000..27fa8974e
--- /dev/null
+++ b/egs/librispeech/ASR/transducer/export.py
@@ -0,0 +1,250 @@
+#!/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.
+"""
+Usage:
+./transducer/export.py \
+ --exp-dir ./transducer/exp \
+ --bpe-model data/lang_bpe_500/bpe.model \
+ --epoch 26 \
+ --avg 12
+
+It will generate a file exp_dir/pretrained.pt
+
+To use the generated file with `transducer/decode.py`, you can do:
+
+ cd /path/to/exp_dir
+ ln -s pretrained.pt epoch-9999.pt
+
+ cd /path/to/egs/librispeech/ASR
+ ./transducer/decode.py \
+ --exp-dir ./transducer/exp \
+ --epoch 9999 \
+ --avg 1 \
+ --max-duration 1 \
+ --bpe-model data/lang_bpe_500/bpe.model
+"""
+
+import argparse
+import logging
+from pathlib import Path
+
+import sentencepiece as spm
+import torch
+from conformer import Conformer
+from decoder import Decoder
+from joiner import Joiner
+from model import Transducer
+
+from icefall.checkpoint import average_checkpoints, load_checkpoint
+from icefall.env import get_env_info
+from icefall.utils import AttributeDict, str2bool
+
+
+def get_parser():
+ parser = argparse.ArgumentParser(
+ formatter_class=argparse.ArgumentDefaultsHelpFormatter
+ )
+
+ parser.add_argument(
+ "--epoch",
+ type=int,
+ default=26,
+ help="It specifies the checkpoint to use for decoding."
+ "Note: Epoch counts from 0.",
+ )
+
+ parser.add_argument(
+ "--avg",
+ type=int,
+ default=12,
+ help="Number of checkpoints to average. Automatically select "
+ "consecutive checkpoints before the checkpoint specified by "
+ "'--epoch'. ",
+ )
+
+ parser.add_argument(
+ "--exp-dir",
+ type=str,
+ default="transducer/exp",
+ help="""It specifies the directory where all training related
+ files, e.g., checkpoints, log, etc, are saved
+ """,
+ )
+
+ parser.add_argument(
+ "--bpe-model",
+ type=str,
+ default="data/lang_bpe_500/bpe.model",
+ help="Path to the BPE model",
+ )
+
+ parser.add_argument(
+ "--jit",
+ type=str2bool,
+ default=False,
+ help="""True to save a model after applying torch.jit.script.
+ """,
+ )
+
+ return parser
+
+
+def get_params() -> AttributeDict:
+ params = AttributeDict(
+ {
+ # parameters for conformer
+ "feature_dim": 80,
+ "encoder_out_dim": 512,
+ "subsampling_factor": 4,
+ "attention_dim": 512,
+ "nhead": 8,
+ "dim_feedforward": 2048,
+ "num_encoder_layers": 12,
+ "vgg_frontend": False,
+ "use_feat_batchnorm": True,
+ # decoder params
+ "decoder_embedding_dim": 1024,
+ "num_decoder_layers": 4,
+ "decoder_hidden_dim": 512,
+ "env_info": get_env_info(),
+ }
+ )
+ return params
+
+
+def get_encoder_model(params: AttributeDict):
+ encoder = Conformer(
+ num_features=params.feature_dim,
+ output_dim=params.encoder_out_dim,
+ subsampling_factor=params.subsampling_factor,
+ d_model=params.attention_dim,
+ nhead=params.nhead,
+ dim_feedforward=params.dim_feedforward,
+ num_encoder_layers=params.num_encoder_layers,
+ vgg_frontend=params.vgg_frontend,
+ use_feat_batchnorm=params.use_feat_batchnorm,
+ )
+ return encoder
+
+
+def get_decoder_model(params: AttributeDict):
+ decoder = Decoder(
+ vocab_size=params.vocab_size,
+ embedding_dim=params.decoder_embedding_dim,
+ blank_id=params.blank_id,
+ sos_id=params.sos_id,
+ num_layers=params.num_decoder_layers,
+ hidden_dim=params.decoder_hidden_dim,
+ output_dim=params.encoder_out_dim,
+ )
+ return decoder
+
+
+def get_joiner_model(params: AttributeDict):
+ joiner = Joiner(
+ input_dim=params.encoder_out_dim,
+ output_dim=params.vocab_size,
+ )
+ return joiner
+
+
+def get_transducer_model(params: AttributeDict):
+ encoder = get_encoder_model(params)
+ decoder = get_decoder_model(params)
+ joiner = get_joiner_model(params)
+
+ model = Transducer(
+ encoder=encoder,
+ decoder=decoder,
+ joiner=joiner,
+ )
+ return model
+
+
+def main():
+ args = get_parser().parse_args()
+ args.exp_dir = Path(args.exp_dir)
+
+ assert args.jit is False, "Support torchscript will be added later"
+
+ params = get_params()
+ params.update(vars(args))
+
+ device = torch.device("cpu")
+ if torch.cuda.is_available():
+ device = torch.device("cuda", 0)
+
+ logging.info(f"device: {device}")
+
+ sp = spm.SentencePieceProcessor()
+ sp.load(params.bpe_model)
+
+ # and are defined in local/train_bpe_model.py
+ params.blank_id = sp.piece_to_id("")
+ params.sos_id = sp.piece_to_id("")
+ params.vocab_size = sp.get_piece_size()
+
+ logging.info(params)
+
+ logging.info("About to create model")
+ model = get_transducer_model(params)
+
+ 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.to(device)
+ model.load_state_dict(average_checkpoints(filenames, device=device))
+
+ model.eval()
+
+ 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()
diff --git a/egs/librispeech/ASR/transducer/joiner.py b/egs/librispeech/ASR/transducer/joiner.py
new file mode 100644
index 000000000..0422f8a6f
--- /dev/null
+++ b/egs/librispeech/ASR/transducer/joiner.py
@@ -0,0 +1,55 @@
+# 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
+import torch.nn.functional as F
+
+
+class Joiner(nn.Module):
+ def __init__(self, input_dim: int, output_dim: int):
+ super().__init__()
+
+ self.output_linear = nn.Linear(input_dim, output_dim)
+
+ def forward(
+ self, encoder_out: torch.Tensor, decoder_out: torch.Tensor
+ ) -> torch.Tensor:
+ """
+ Args:
+ encoder_out:
+ Output from the encoder. Its shape is (N, T, C).
+ decoder_out:
+ Output from the decoder. Its shape is (N, U, C).
+ Returns:
+ Return a tensor of shape (N, T, U, C).
+ """
+ assert encoder_out.ndim == decoder_out.ndim == 3
+ assert encoder_out.size(0) == decoder_out.size(0)
+ assert encoder_out.size(2) == decoder_out.size(2)
+
+ encoder_out = encoder_out.unsqueeze(2)
+ # Now encoder_out is (N, T, 1, C)
+
+ decoder_out = decoder_out.unsqueeze(1)
+ # Now decoder_out is (N, 1, U, C)
+
+ logit = encoder_out + decoder_out
+ logit = F.relu(logit)
+
+ output = self.output_linear(logit)
+
+ return output
diff --git a/egs/librispeech/ASR/transducer/model.py b/egs/librispeech/ASR/transducer/model.py
new file mode 100644
index 000000000..8a4d3ca69
--- /dev/null
+++ b/egs/librispeech/ASR/transducer/model.py
@@ -0,0 +1,127 @@
+# 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.
+
+"""
+Note we use `rnnt_loss` from torchaudio, which exists only in
+torchaudio >= v0.10.0. It also means you have to use torch >= v1.10.0
+"""
+import k2
+import torch
+import torch.nn as nn
+import torchaudio
+import torchaudio.functional
+from encoder_interface import EncoderInterface
+
+from icefall.utils import add_sos
+
+assert hasattr(torchaudio.functional, "rnnt_loss"), (
+ f"Current torchaudio version: {torchaudio.__version__}\n"
+ "Please install a version >= 0.10.0"
+)
+
+
+class Transducer(nn.Module):
+ """It implements https://arxiv.org/pdf/1211.3711.pdf
+ "Sequence Transduction with Recurrent Neural Networks"
+ """
+
+ def __init__(
+ self,
+ encoder: EncoderInterface,
+ decoder: nn.Module,
+ joiner: nn.Module,
+ ):
+ """
+ Args:
+ encoder:
+ It is the transcription network in the paper. Its accepts
+ two inputs: `x` of (N, T, C) and `x_lens` of shape (N,).
+ It returns two tensors: `logits` of shape (N, T, C) and
+ `logit_lens` of shape (N,).
+ decoder:
+ It is the prediction network in the paper. Its input shape
+ is (N, U) and its output shape is (N, U, C). It should contain
+ two attributes: `blank_id` and `sos_id`.
+ joiner:
+ It has two inputs with shapes: (N, T, C) and (N, U, C). Its
+ output shape is (N, T, U, C). Note that its output contains
+ unnormalized probs, i.e., not processed by log-softmax.
+ """
+ super().__init__()
+ assert isinstance(encoder, EncoderInterface)
+ assert hasattr(decoder, "blank_id")
+ assert hasattr(decoder, "sos_id")
+
+ self.encoder = encoder
+ self.decoder = decoder
+ self.joiner = joiner
+
+ def forward(
+ self,
+ x: torch.Tensor,
+ x_lens: torch.Tensor,
+ y: k2.RaggedTensor,
+ ) -> torch.Tensor:
+ """
+ Args:
+ x:
+ A 3-D tensor of shape (N, T, C).
+ x_lens:
+ A 1-D tensor of shape (N,). It contains the number of frames in `x`
+ before padding.
+ y:
+ A ragged tensor with 2 axes [utt][label]. It contains labels of each
+ utterance.
+ Returns:
+ Return the transducer loss.
+ """
+ assert x.ndim == 3, x.shape
+ assert x_lens.ndim == 1, x_lens.shape
+ assert y.num_axes == 2, y.num_axes
+
+ assert x.size(0) == x_lens.size(0) == y.dim0
+
+ encoder_out, x_lens = self.encoder(x, x_lens)
+ assert torch.all(x_lens > 0)
+
+ # Now for the decoder, i.e., the prediction network
+ row_splits = y.shape.row_splits(1)
+ y_lens = row_splits[1:] - row_splits[:-1]
+
+ blank_id = self.decoder.blank_id
+ sos_id = self.decoder.sos_id
+ sos_y = add_sos(y, sos_id=sos_id)
+
+ sos_y_padded = sos_y.pad(mode="constant", padding_value=blank_id)
+
+ decoder_out, _ = self.decoder(sos_y_padded)
+
+ logits = self.joiner(encoder_out, decoder_out)
+
+ # rnnt_loss requires 0 padded targets
+ # Note: y does not start with SOS
+ y_padded = y.pad(mode="constant", padding_value=0)
+
+ loss = torchaudio.functional.rnnt_loss(
+ logits=logits,
+ targets=y_padded,
+ logit_lengths=x_lens,
+ target_lengths=y_lens,
+ blank=blank_id,
+ reduction="sum",
+ )
+
+ return loss
diff --git a/egs/librispeech/ASR/transducer/pretrained.py b/egs/librispeech/ASR/transducer/pretrained.py
new file mode 100755
index 000000000..4cf4fd4a7
--- /dev/null
+++ b/egs/librispeech/ASR/transducer/pretrained.py
@@ -0,0 +1,299 @@
+#!/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:
+
+./transducer/pretrained.py \
+ --checkpoint ./transducer/exp/pretrained.pt \
+ --bpe-model ./data/lang_bpe_500/bpe.model \
+ --method greedy_search \
+ /path/to/foo.wav \
+ /path/to/bar.wav \
+
+You can also use `./transducer/exp/epoch-xx.pt`.
+
+Note: ./transducer/exp/pretrained.pt is generated by
+./transducer/export.py
+"""
+
+
+import argparse
+import logging
+import math
+from typing import List
+
+import kaldifeat
+import sentencepiece as spm
+import torch
+import torchaudio
+from beam_search import beam_search, greedy_search
+from conformer import Conformer
+from decoder import Decoder
+from joiner import Joiner
+from model import Transducer
+from torch.nn.utils.rnn import pad_sequence
+
+from icefall.env import get_env_info
+from icefall.utils import AttributeDict
+
+
+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(
+ "--bpe-model",
+ type=str,
+ help="""Path to bpe.model.
+ Used only when method is ctc-decoding.
+ """,
+ )
+
+ parser.add_argument(
+ "--method",
+ type=str,
+ default="greedy_search",
+ help="""Possible values are:
+ - greedy_search
+ - beam_search
+ """,
+ )
+
+ 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.",
+ )
+
+ parser.add_argument(
+ "--beam-size",
+ type=int,
+ default=5,
+ help="Used only when --method is beam_search",
+ )
+
+ return parser
+
+
+def get_params() -> AttributeDict:
+ params = AttributeDict(
+ {
+ "sample_rate": 16000,
+ # parameters for conformer
+ "feature_dim": 80,
+ "encoder_out_dim": 512,
+ "subsampling_factor": 4,
+ "attention_dim": 512,
+ "nhead": 8,
+ "dim_feedforward": 2048,
+ "num_encoder_layers": 12,
+ "vgg_frontend": False,
+ "use_feat_batchnorm": True,
+ # decoder params
+ "decoder_embedding_dim": 1024,
+ "num_decoder_layers": 4,
+ "decoder_hidden_dim": 512,
+ "env_info": get_env_info(),
+ }
+ )
+ return params
+
+
+def get_encoder_model(params: AttributeDict):
+ encoder = Conformer(
+ num_features=params.feature_dim,
+ output_dim=params.encoder_out_dim,
+ subsampling_factor=params.subsampling_factor,
+ d_model=params.attention_dim,
+ nhead=params.nhead,
+ dim_feedforward=params.dim_feedforward,
+ num_encoder_layers=params.num_encoder_layers,
+ vgg_frontend=params.vgg_frontend,
+ use_feat_batchnorm=params.use_feat_batchnorm,
+ )
+ return encoder
+
+
+def get_decoder_model(params: AttributeDict):
+ decoder = Decoder(
+ vocab_size=params.vocab_size,
+ embedding_dim=params.decoder_embedding_dim,
+ blank_id=params.blank_id,
+ sos_id=params.sos_id,
+ num_layers=params.num_decoder_layers,
+ hidden_dim=params.decoder_hidden_dim,
+ output_dim=params.encoder_out_dim,
+ )
+ return decoder
+
+
+def get_joiner_model(params: AttributeDict):
+ joiner = Joiner(
+ input_dim=params.encoder_out_dim,
+ output_dim=params.vocab_size,
+ )
+ return joiner
+
+
+def get_transducer_model(params: AttributeDict):
+ encoder = get_encoder_model(params)
+ decoder = get_decoder_model(params)
+ joiner = get_joiner_model(params)
+
+ model = Transducer(
+ encoder=encoder,
+ decoder=decoder,
+ joiner=joiner,
+ )
+ return model
+
+
+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}. "
+ f"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()
+
+ params.update(vars(args))
+
+ sp = spm.SentencePieceProcessor()
+ sp.load(params.bpe_model)
+
+ # and are defined in local/train_bpe_model.py
+ params.blank_id = sp.piece_to_id("")
+ params.sos_id = sp.piece_to_id("")
+ params.vocab_size = sp.get_piece_size()
+
+ 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 = get_transducer_model(params)
+
+ checkpoint = torch.load(args.checkpoint, map_location="cpu")
+ model.load_state_dict(checkpoint["model"], strict=False)
+ model.to(device)
+ model.eval()
+ model.device = device
+
+ 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)
+ feature_lengths = [f.size(0) for f in features]
+
+ features = pad_sequence(
+ features, batch_first=True, padding_value=math.log(1e-10)
+ )
+
+ feature_lengths = torch.tensor(feature_lengths, device=device)
+
+ with torch.no_grad():
+ encoder_out, encoder_out_lens = model.encoder(
+ x=features, x_lens=feature_lengths
+ )
+
+ num_waves = encoder_out.size(0)
+ hyps = []
+ for i in range(num_waves):
+ # fmt: off
+ encoder_out_i = encoder_out[i:i+1, :encoder_out_lens[i]]
+ # fmt: on
+ if params.method == "greedy_search":
+ hyp = greedy_search(model=model, encoder_out=encoder_out_i)
+ elif params.method == "beam_search":
+ hyp = beam_search(
+ model=model, encoder_out=encoder_out_i, beam=params.beam_size
+ )
+ else:
+ raise ValueError(f"Unsupported method: {params.method}")
+
+ hyps.append(sp.decode(hyp).split())
+
+ 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()
diff --git a/egs/librispeech/ASR/transducer/rnn.py b/egs/librispeech/ASR/transducer/rnn.py
index 8e695db50..2a165b0c1 100644
--- a/egs/librispeech/ASR/transducer/rnn.py
+++ b/egs/librispeech/ASR/transducer/rnn.py
@@ -212,6 +212,24 @@ class LayerNormLSTMCell(nn.Module):
if "layernorm" not in name:
nn.init.uniform_(weight, -stdv, stdv)
+ if "bias_ih" in name or "bias_hh" in name:
+ # See the paper
+ # An Empirical Exploration of Recurrent Network Architectures
+ # https://proceedings.mlr.press/v37/jozefowicz15.pdf
+ #
+ # It recommends initializing the bias of the forget gate to
+ # a large value, such as 1 or 2. In PyTorch, there are two
+ # biases for the forget gate, we set both of them to 1 here.
+ #
+ # See also https://arxiv.org/pdf/1804.04849.pdf
+ assert weight.ndim == 1
+ # Layout of the bias:
+ # | in_gate | forget_gate | cell_gate | output_gate |
+ start = weight.numel() // 4
+ end = weight.numel() // 2
+ with torch.no_grad():
+ weight[start:end].fill_(1.0)
+
class LayerNormLSTMLayer(nn.Module):
"""
diff --git a/egs/librispeech/ASR/transducer/subsampling.py b/egs/librispeech/ASR/transducer/subsampling.py
new file mode 120000
index 000000000..6fee09e58
--- /dev/null
+++ b/egs/librispeech/ASR/transducer/subsampling.py
@@ -0,0 +1 @@
+../conformer_ctc/subsampling.py
\ No newline at end of file
diff --git a/egs/librispeech/ASR/transducer/test_conformer.py b/egs/librispeech/ASR/transducer/test_conformer.py
new file mode 100755
index 000000000..5d941d98a
--- /dev/null
+++ b/egs/librispeech/ASR/transducer/test_conformer.py
@@ -0,0 +1,60 @@
+#!/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.
+
+"""
+To run this file, do:
+
+ cd icefall/egs/librispeech/ASR
+ python ./transducer/test_conformer.py
+"""
+
+import torch
+from conformer import Conformer
+
+
+def test_conformer():
+ output_dim = 1024
+ conformer = Conformer(
+ num_features=80,
+ output_dim=output_dim,
+ subsampling_factor=4,
+ d_model=512,
+ nhead=8,
+ dim_feedforward=2048,
+ num_encoder_layers=12,
+ use_feat_batchnorm=True,
+ )
+ N = 3
+ T = 100
+ C = 80
+ x = torch.randn(N, T, C)
+ x_lens = torch.tensor([50, 100, 80])
+ logits, logit_lens = conformer(x, x_lens)
+
+ expected_T = ((T - 1) // 2 - 1) // 2
+ assert logits.shape == (N, expected_T, output_dim)
+ assert logit_lens.max().item() == expected_T
+ print(logits.shape)
+ print(logit_lens)
+
+
+def main():
+ test_conformer()
+
+
+if __name__ == "__main__":
+ main()
diff --git a/egs/librispeech/ASR/transducer/test_decoder.py b/egs/librispeech/ASR/transducer/test_decoder.py
new file mode 100755
index 000000000..44c6eb6db
--- /dev/null
+++ b/egs/librispeech/ASR/transducer/test_decoder.py
@@ -0,0 +1,69 @@
+#!/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.
+
+"""
+To run this file, do:
+
+ cd icefall/egs/librispeech/ASR
+ python ./transducer/test_decoder.py
+"""
+
+import torch
+from decoder import Decoder
+
+
+def test_decoder():
+ vocab_size = 3
+ blank_id = 0
+ sos_id = 2
+ embedding_dim = 128
+ num_layers = 2
+ hidden_dim = 6
+ output_dim = 8
+ N = 3
+ U = 5
+
+ decoder = Decoder(
+ vocab_size=vocab_size,
+ embedding_dim=embedding_dim,
+ blank_id=blank_id,
+ sos_id=sos_id,
+ num_layers=num_layers,
+ hidden_dim=hidden_dim,
+ output_dim=output_dim,
+ embedding_dropout=0.0,
+ rnn_dropout=0.0,
+ )
+ x = torch.randint(1, vocab_size, (N, U))
+ decoder_out, (h, c) = decoder(x)
+
+ assert decoder_out.shape == (N, U, output_dim)
+ assert h.shape == (num_layers, N, hidden_dim)
+ assert c.shape == (num_layers, N, hidden_dim)
+
+ decoder_out, (h, c) = decoder(x, (h, c))
+ assert decoder_out.shape == (N, U, output_dim)
+ assert h.shape == (num_layers, N, hidden_dim)
+ assert c.shape == (num_layers, N, hidden_dim)
+
+
+def main():
+ test_decoder()
+
+
+if __name__ == "__main__":
+ main()
diff --git a/egs/librispeech/ASR/transducer/test_joiner.py b/egs/librispeech/ASR/transducer/test_joiner.py
new file mode 100755
index 000000000..23948bbf6
--- /dev/null
+++ b/egs/librispeech/ASR/transducer/test_joiner.py
@@ -0,0 +1,50 @@
+#!/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.
+
+"""
+To run this file, do:
+
+ cd icefall/egs/librispeech/ASR
+ python ./transducer/test_joiner.py
+"""
+
+
+import torch
+from joiner import Joiner
+
+
+def test_joiner():
+ N = 2
+ T = 3
+ C = 4
+ U = 5
+
+ joiner = Joiner(C, 10)
+
+ encoder_out = torch.rand(N, T, C)
+ decoder_out = torch.rand(N, U, C)
+
+ joint = joiner(encoder_out, decoder_out)
+ assert joint.shape == (N, T, U, 10)
+
+
+def main():
+ test_joiner()
+
+
+if __name__ == "__main__":
+ main()
diff --git a/egs/librispeech/ASR/transducer/test_rnn.py b/egs/librispeech/ASR/transducer/test_rnn.py
index c7d524f7d..8591e2d8a 100755
--- a/egs/librispeech/ASR/transducer/test_rnn.py
+++ b/egs/librispeech/ASR/transducer/test_rnn.py
@@ -15,9 +15,15 @@
# See the License for the specific language governing permissions and
# limitations under the License.
+"""
+To run this file, do:
+
+ cd icefall/egs/librispeech/ASR
+ python ./transducer/test_rnn.py
+"""
import torch
import torch.nn as nn
-from transducer.rnn import (
+from rnn import (
LayerNormGRU,
LayerNormGRUCell,
LayerNormGRULayer,
@@ -499,6 +505,28 @@ def test_layernorm_lstm_with_projection_forward(device="cpu"):
assert_allclose(x.grad, x_clone.grad)
+def test_lstm_forget_gate_bias(device="cpu"):
+ input_size = 2
+ hidden_size = 3
+ num_layers = 4
+ bias = True
+
+ lstm = LayerNormLSTM(
+ input_size=input_size,
+ hidden_size=hidden_size,
+ num_layers=num_layers,
+ bias=bias,
+ ln=nn.Identity,
+ device=device,
+ )
+ for name, weight in lstm.named_parameters():
+ if "bias_hh" in name or "bias_ih" in name:
+ start = weight.numel() // 4
+ end = weight.numel() // 2
+ expected = torch.ones(hidden_size).to(weight)
+ assert torch.all(torch.eq(weight[start:end], expected))
+
+
def test_layernorm_gru_cell_jit(device="cpu"):
input_size = 10
hidden_size = 20
@@ -735,6 +763,8 @@ def _test_lstm(device):
test_layernorm_lstm_with_projection_jit(device)
test_layernorm_lstm_forward(device)
test_layernorm_lstm_with_projection_forward(device)
+ #
+ test_lstm_forget_gate_bias(device)
def _test_gru(device):
diff --git a/egs/librispeech/ASR/transducer/test_transducer.py b/egs/librispeech/ASR/transducer/test_transducer.py
new file mode 100755
index 000000000..bd4f2c188
--- /dev/null
+++ b/egs/librispeech/ASR/transducer/test_transducer.py
@@ -0,0 +1,89 @@
+#!/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.
+
+"""
+To run this file, do:
+
+ cd icefall/egs/librispeech/ASR
+ python ./transducer/test_transducer.py
+"""
+
+
+import k2
+import torch
+from conformer import Conformer
+from decoder import Decoder
+from joiner import Joiner
+from model import Transducer
+
+
+def test_transducer():
+ # encoder params
+ input_dim = 10
+ output_dim = 20
+
+ # decoder params
+ vocab_size = 3
+ blank_id = 0
+ sos_id = 2
+ embedding_dim = 128
+ num_layers = 2
+
+ encoder = Conformer(
+ num_features=input_dim,
+ output_dim=output_dim,
+ subsampling_factor=4,
+ d_model=512,
+ nhead=8,
+ dim_feedforward=2048,
+ num_encoder_layers=12,
+ use_feat_batchnorm=True,
+ )
+
+ decoder = Decoder(
+ vocab_size=vocab_size,
+ embedding_dim=embedding_dim,
+ blank_id=blank_id,
+ sos_id=sos_id,
+ num_layers=num_layers,
+ hidden_dim=output_dim,
+ output_dim=output_dim,
+ embedding_dropout=0.0,
+ rnn_dropout=0.0,
+ )
+
+ joiner = Joiner(output_dim, vocab_size)
+ transducer = Transducer(encoder=encoder, decoder=decoder, joiner=joiner)
+
+ y = k2.RaggedTensor([[1, 2, 1], [1, 1, 1, 2, 1]])
+ N = y.dim0
+ T = 50
+
+ x = torch.rand(N, T, input_dim)
+ x_lens = torch.randint(low=30, high=T, size=(N,), dtype=torch.int32)
+ x_lens[0] = T
+
+ loss = transducer(x, x_lens, y)
+ print(loss)
+
+
+def main():
+ test_transducer()
+
+
+if __name__ == "__main__":
+ main()
diff --git a/egs/librispeech/ASR/transducer/test_transformer.py b/egs/librispeech/ASR/transducer/test_transformer.py
new file mode 100755
index 000000000..8f4585504
--- /dev/null
+++ b/egs/librispeech/ASR/transducer/test_transformer.py
@@ -0,0 +1,60 @@
+#!/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.
+
+"""
+To run this file, do:
+
+ cd icefall/egs/librispeech/ASR
+ python ./transducer/test_transformer.py
+"""
+
+import torch
+from transformer import Transformer
+
+
+def test_transformer():
+ output_dim = 1024
+ transformer = Transformer(
+ num_features=80,
+ output_dim=output_dim,
+ subsampling_factor=4,
+ d_model=512,
+ nhead=8,
+ dim_feedforward=2048,
+ num_encoder_layers=12,
+ use_feat_batchnorm=True,
+ )
+ N = 3
+ T = 100
+ C = 80
+ x = torch.randn(N, T, C)
+ x_lens = torch.tensor([50, 100, 80])
+ logits, logit_lens = transformer(x, x_lens)
+
+ expected_T = ((T - 1) // 2 - 1) // 2
+ assert logits.shape == (N, expected_T, output_dim)
+ assert logit_lens.max().item() == expected_T
+ print(logits.shape)
+ print(logit_lens)
+
+
+def main():
+ test_transformer()
+
+
+if __name__ == "__main__":
+ main()
diff --git a/egs/librispeech/ASR/transducer/train.py b/egs/librispeech/ASR/transducer/train.py
new file mode 100755
index 000000000..5d0b2d33a
--- /dev/null
+++ b/egs/librispeech/ASR/transducer/train.py
@@ -0,0 +1,743 @@
+#!/usr/bin/env python3
+# Copyright 2021 Xiaomi Corp. (authors: Fangjun Kuang,
+# Wei Kang
+# 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.
+"""
+Usage:
+
+export CUDA_VISIBLE_DEVICES="0,1,2,3"
+
+./transducer/train.py \
+ --world-size 4 \
+ --num-epochs 30 \
+ --start-epoch 0 \
+ --exp-dir transducer/exp \
+ --full-libri 1 \
+ --max-duration 250 \
+ --lr-factor 2.5
+"""
+
+
+import argparse
+import logging
+from pathlib import Path
+from shutil import copyfile
+from typing import Optional, Tuple
+
+import k2
+import sentencepiece as spm
+import torch
+import torch.multiprocessing as mp
+import torch.nn as nn
+from asr_datamodule import LibriSpeechAsrDataModule
+from conformer import Conformer
+from decoder import Decoder
+from joiner import Joiner
+from lhotse.cut import Cut
+from lhotse.utils import fix_random_seed
+from model import Transducer
+from torch import Tensor
+from torch.nn.parallel import DistributedDataParallel as DDP
+from torch.nn.utils import clip_grad_norm_
+from torch.utils.tensorboard import SummaryWriter
+from transformer import Noam
+
+from icefall.checkpoint import load_checkpoint
+from icefall.checkpoint import save_checkpoint as save_checkpoint_impl
+from icefall.dist import cleanup_dist, setup_dist
+from icefall.env import get_env_info
+from icefall.utils import AttributeDict, MetricsTracker, setup_logger, str2bool
+
+
+def get_parser():
+ parser = argparse.ArgumentParser(
+ formatter_class=argparse.ArgumentDefaultsHelpFormatter
+ )
+
+ parser.add_argument(
+ "--world-size",
+ type=int,
+ default=1,
+ help="Number of GPUs for DDP training.",
+ )
+
+ parser.add_argument(
+ "--master-port",
+ type=int,
+ default=12354,
+ help="Master port to use for DDP training.",
+ )
+
+ parser.add_argument(
+ "--tensorboard",
+ type=str2bool,
+ default=True,
+ help="Should various information be logged in tensorboard.",
+ )
+
+ parser.add_argument(
+ "--num-epochs",
+ type=int,
+ default=30,
+ help="Number of epochs to train.",
+ )
+
+ parser.add_argument(
+ "--start-epoch",
+ type=int,
+ default=0,
+ help="""Resume training from from this epoch.
+ If it is positive, it will load checkpoint from
+ transducer/exp/epoch-{start_epoch-1}.pt
+ """,
+ )
+
+ parser.add_argument(
+ "--exp-dir",
+ type=str,
+ default="transducer/exp",
+ help="""The experiment dir.
+ It specifies the directory where all training related
+ files, e.g., checkpoints, log, etc, are saved
+ """,
+ )
+
+ parser.add_argument(
+ "--bpe-model",
+ type=str,
+ default="data/lang_bpe_500/bpe.model",
+ help="Path to the BPE model",
+ )
+
+ parser.add_argument(
+ "--lr-factor",
+ type=float,
+ default=3.0,
+ help="The lr_factor for Noam optimizer",
+ )
+
+ return parser
+
+
+def get_params() -> AttributeDict:
+ """Return a dict containing training parameters.
+
+ All training related parameters that are not passed from the commandline
+ are saved in the variable `params`.
+
+ Commandline options are merged into `params` after they are parsed, so
+ you can also access them via `params`.
+
+ Explanation of options saved in `params`:
+
+ - best_train_loss: Best training loss so far. It is used to select
+ the model that has the lowest training loss. It is
+ updated during the training.
+
+ - best_valid_loss: Best validation loss so far. It is used to select
+ the model that has the lowest validation loss. It is
+ updated during the training.
+
+ - best_train_epoch: It is the epoch that has the best training loss.
+
+ - best_valid_epoch: It is the epoch that has the best validation loss.
+
+ - batch_idx_train: Used to writing statistics to tensorboard. It
+ contains number of batches trained so far across
+ epochs.
+
+ - log_interval: Print training loss if batch_idx % log_interval` is 0
+
+ - reset_interval: Reset statistics if batch_idx % reset_interval is 0
+
+ - valid_interval: Run validation if batch_idx % valid_interval is 0
+
+ - feature_dim: The model input dim. It has to match the one used
+ in computing features.
+
+ - subsampling_factor: The subsampling factor for the model.
+
+ - use_feat_batchnorm: Whether to do batch normalization for the
+ input features.
+
+ - attention_dim: Hidden dim for multi-head attention model.
+
+ - num_decoder_layers: Number of decoder layer of transformer decoder.
+
+ - weight_decay: The weight_decay for the optimizer.
+
+ - warm_step: The warm_step for Noam optimizer.
+ """
+ params = AttributeDict(
+ {
+ "best_train_loss": float("inf"),
+ "best_valid_loss": float("inf"),
+ "best_train_epoch": -1,
+ "best_valid_epoch": -1,
+ "batch_idx_train": 0,
+ "log_interval": 50,
+ "reset_interval": 200,
+ "valid_interval": 3000, # For the 100h subset, use 800
+ # parameters for conformer
+ "feature_dim": 80,
+ "encoder_out_dim": 512,
+ "subsampling_factor": 4,
+ "attention_dim": 512,
+ "nhead": 8,
+ "dim_feedforward": 2048,
+ "num_encoder_layers": 12,
+ "vgg_frontend": False,
+ "use_feat_batchnorm": True,
+ # decoder params
+ "decoder_embedding_dim": 1024,
+ "num_decoder_layers": 4,
+ "decoder_hidden_dim": 512,
+ # parameters for Noam
+ "weight_decay": 1e-6,
+ "warm_step": 80000, # For the 100h subset, use 8k
+ "env_info": get_env_info(),
+ }
+ )
+
+ return params
+
+
+def get_encoder_model(params: AttributeDict):
+ # TODO: We can add an option to switch between Conformer and Transformer
+ encoder = Conformer(
+ num_features=params.feature_dim,
+ output_dim=params.encoder_out_dim,
+ subsampling_factor=params.subsampling_factor,
+ d_model=params.attention_dim,
+ nhead=params.nhead,
+ dim_feedforward=params.dim_feedforward,
+ num_encoder_layers=params.num_encoder_layers,
+ vgg_frontend=params.vgg_frontend,
+ use_feat_batchnorm=params.use_feat_batchnorm,
+ )
+ return encoder
+
+
+def get_decoder_model(params: AttributeDict):
+ decoder = Decoder(
+ vocab_size=params.vocab_size,
+ embedding_dim=params.decoder_embedding_dim,
+ blank_id=params.blank_id,
+ sos_id=params.sos_id,
+ num_layers=params.num_decoder_layers,
+ hidden_dim=params.decoder_hidden_dim,
+ output_dim=params.encoder_out_dim,
+ )
+ return decoder
+
+
+def get_joiner_model(params: AttributeDict):
+ joiner = Joiner(
+ input_dim=params.encoder_out_dim,
+ output_dim=params.vocab_size,
+ )
+ return joiner
+
+
+def get_transducer_model(params: AttributeDict):
+ encoder = get_encoder_model(params)
+ decoder = get_decoder_model(params)
+ joiner = get_joiner_model(params)
+
+ model = Transducer(
+ encoder=encoder,
+ decoder=decoder,
+ joiner=joiner,
+ )
+ return model
+
+
+def load_checkpoint_if_available(
+ params: AttributeDict,
+ model: nn.Module,
+ optimizer: Optional[torch.optim.Optimizer] = None,
+ scheduler: Optional[torch.optim.lr_scheduler._LRScheduler] = None,
+) -> None:
+ """Load checkpoint from file.
+
+ If params.start_epoch is positive, it will load the checkpoint from
+ `params.start_epoch - 1`. Otherwise, this function does nothing.
+
+ Apart from loading state dict for `model`, `optimizer` and `scheduler`,
+ it also updates `best_train_epoch`, `best_train_loss`, `best_valid_epoch`,
+ and `best_valid_loss` in `params`.
+
+ Args:
+ params:
+ The return value of :func:`get_params`.
+ model:
+ The training model.
+ optimizer:
+ The optimizer that we are using.
+ scheduler:
+ The learning rate scheduler we are using.
+ Returns:
+ Return None.
+ """
+ if params.start_epoch <= 0:
+ return
+
+ filename = params.exp_dir / f"epoch-{params.start_epoch-1}.pt"
+ saved_params = load_checkpoint(
+ filename,
+ model=model,
+ optimizer=optimizer,
+ scheduler=scheduler,
+ )
+
+ keys = [
+ "best_train_epoch",
+ "best_valid_epoch",
+ "batch_idx_train",
+ "best_train_loss",
+ "best_valid_loss",
+ ]
+ for k in keys:
+ params[k] = saved_params[k]
+
+ return saved_params
+
+
+def save_checkpoint(
+ params: AttributeDict,
+ model: nn.Module,
+ optimizer: Optional[torch.optim.Optimizer] = None,
+ scheduler: Optional[torch.optim.lr_scheduler._LRScheduler] = None,
+ rank: int = 0,
+) -> None:
+ """Save model, optimizer, scheduler and training stats to file.
+
+ Args:
+ params:
+ It is returned by :func:`get_params`.
+ model:
+ The training model.
+ """
+ if rank != 0:
+ return
+ filename = params.exp_dir / f"epoch-{params.cur_epoch}.pt"
+ save_checkpoint_impl(
+ filename=filename,
+ model=model,
+ params=params,
+ optimizer=optimizer,
+ scheduler=scheduler,
+ rank=rank,
+ )
+
+ if params.best_train_epoch == params.cur_epoch:
+ best_train_filename = params.exp_dir / "best-train-loss.pt"
+ copyfile(src=filename, dst=best_train_filename)
+
+ if params.best_valid_epoch == params.cur_epoch:
+ best_valid_filename = params.exp_dir / "best-valid-loss.pt"
+ copyfile(src=filename, dst=best_valid_filename)
+
+
+def compute_loss(
+ params: AttributeDict,
+ model: nn.Module,
+ sp: spm.SentencePieceProcessor,
+ batch: dict,
+ is_training: bool,
+) -> Tuple[Tensor, MetricsTracker]:
+ """
+ Compute CTC loss given the model and its inputs.
+
+ Args:
+ params:
+ Parameters for training. See :func:`get_params`.
+ model:
+ The model for training. It is an instance of Conformer in our case.
+ batch:
+ A batch of data. See `lhotse.dataset.K2SpeechRecognitionDataset()`
+ for the content in it.
+ is_training:
+ True for training. False for validation. When it is True, this
+ function enables autograd during computation; when it is False, it
+ disables autograd.
+ """
+ device = model.device
+ feature = batch["inputs"]
+ # at entry, feature is (N, T, C)
+ assert feature.ndim == 3
+ feature = feature.to(device)
+
+ supervisions = batch["supervisions"]
+ feature_lens = supervisions["num_frames"].to(device)
+
+ texts = batch["supervisions"]["text"]
+ y = sp.encode(texts, out_type=int)
+ y = k2.RaggedTensor(y).to(device)
+
+ with torch.set_grad_enabled(is_training):
+ loss = model(x=feature, x_lens=feature_lens, y=y)
+
+ assert loss.requires_grad == is_training
+
+ info = MetricsTracker()
+ info["frames"] = (feature_lens // params.subsampling_factor).sum().item()
+
+ # Note: We use reduction=sum while computing the loss.
+ info["loss"] = loss.detach().cpu().item()
+
+ return loss, info
+
+
+def compute_validation_loss(
+ params: AttributeDict,
+ model: nn.Module,
+ sp: spm.SentencePieceProcessor,
+ valid_dl: torch.utils.data.DataLoader,
+ world_size: int = 1,
+) -> MetricsTracker:
+ """Run the validation process."""
+ model.eval()
+
+ tot_loss = MetricsTracker()
+
+ for batch_idx, batch in enumerate(valid_dl):
+ loss, loss_info = compute_loss(
+ params=params,
+ model=model,
+ sp=sp,
+ batch=batch,
+ is_training=False,
+ )
+ assert loss.requires_grad is False
+ tot_loss = tot_loss + loss_info
+
+ if world_size > 1:
+ tot_loss.reduce(loss.device)
+
+ loss_value = tot_loss["loss"] / tot_loss["frames"]
+ if loss_value < params.best_valid_loss:
+ params.best_valid_epoch = params.cur_epoch
+ params.best_valid_loss = loss_value
+
+ return tot_loss
+
+
+def train_one_epoch(
+ params: AttributeDict,
+ model: nn.Module,
+ optimizer: torch.optim.Optimizer,
+ sp: spm.SentencePieceProcessor,
+ train_dl: torch.utils.data.DataLoader,
+ valid_dl: torch.utils.data.DataLoader,
+ tb_writer: Optional[SummaryWriter] = None,
+ world_size: int = 1,
+) -> None:
+ """Train the model for one epoch.
+
+ The training loss from the mean of all frames is saved in
+ `params.train_loss`. It runs the validation process every
+ `params.valid_interval` batches.
+
+ Args:
+ params:
+ It is returned by :func:`get_params`.
+ model:
+ The model for training.
+ optimizer:
+ The optimizer we are using.
+ train_dl:
+ Dataloader for the training dataset.
+ valid_dl:
+ Dataloader for the validation dataset.
+ tb_writer:
+ Writer to write log messages to tensorboard.
+ world_size:
+ Number of nodes in DDP training. If it is 1, DDP is disabled.
+ """
+ model.train()
+
+ tot_loss = MetricsTracker()
+
+ for batch_idx, batch in enumerate(train_dl):
+ params.batch_idx_train += 1
+ batch_size = len(batch["supervisions"]["text"])
+
+ loss, loss_info = compute_loss(
+ params=params,
+ model=model,
+ sp=sp,
+ batch=batch,
+ is_training=True,
+ )
+ # summary stats
+ tot_loss = (tot_loss * (1 - 1 / params.reset_interval)) + loss_info
+
+ # NOTE: We use reduction==sum and loss is computed over utterances
+ # in the batch and there is no normalization to it so far.
+
+ optimizer.zero_grad()
+ loss.backward()
+ clip_grad_norm_(model.parameters(), 5.0, 2.0)
+ optimizer.step()
+
+ if batch_idx % params.log_interval == 0:
+ logging.info(
+ f"Epoch {params.cur_epoch}, "
+ f"batch {batch_idx}, loss[{loss_info}], "
+ f"tot_loss[{tot_loss}], batch size: {batch_size}"
+ )
+
+ if batch_idx % params.log_interval == 0:
+
+ if tb_writer is not None:
+ loss_info.write_summary(
+ tb_writer, "train/current_", params.batch_idx_train
+ )
+ tot_loss.write_summary(
+ tb_writer, "train/tot_", params.batch_idx_train
+ )
+
+ if batch_idx > 0 and batch_idx % params.valid_interval == 0:
+ logging.info("Computing validation loss")
+ valid_info = compute_validation_loss(
+ params=params,
+ model=model,
+ sp=sp,
+ valid_dl=valid_dl,
+ world_size=world_size,
+ )
+ model.train()
+ logging.info(f"Epoch {params.cur_epoch}, validation: {valid_info}")
+ if tb_writer is not None:
+ valid_info.write_summary(
+ tb_writer, "train/valid_", params.batch_idx_train
+ )
+
+ loss_value = tot_loss["loss"] / tot_loss["frames"]
+ params.train_loss = loss_value
+ if params.train_loss < params.best_train_loss:
+ params.best_train_epoch = params.cur_epoch
+ params.best_train_loss = params.train_loss
+
+
+def run(rank, world_size, args):
+ """
+ Args:
+ rank:
+ It is a value between 0 and `world_size-1`, which is
+ passed automatically by `mp.spawn()` in :func:`main`.
+ The node with rank 0 is responsible for saving checkpoint.
+ world_size:
+ Number of GPUs for DDP training.
+ args:
+ The return value of get_parser().parse_args()
+ """
+ params = get_params()
+ params.update(vars(args))
+ if params.full_libri is False:
+ params.valid_interval = 800
+ params.warm_step = 8000
+
+ fix_random_seed(42)
+ if world_size > 1:
+ setup_dist(rank, world_size, params.master_port)
+
+ setup_logger(f"{params.exp_dir}/log/log-train")
+ logging.info("Training started")
+
+ if args.tensorboard and rank == 0:
+ tb_writer = SummaryWriter(log_dir=f"{params.exp_dir}/tensorboard")
+ else:
+ tb_writer = None
+
+ device = torch.device("cpu")
+ if torch.cuda.is_available():
+ device = torch.device("cuda", rank)
+ logging.info(f"Device: {device}")
+
+ sp = spm.SentencePieceProcessor()
+ sp.load(params.bpe_model)
+
+ # and are defined in local/train_bpe_model.py
+ params.blank_id = sp.piece_to_id("")
+ params.sos_id = sp.piece_to_id("")
+ params.vocab_size = sp.get_piece_size()
+
+ logging.info(params)
+
+ logging.info("About to create model")
+ model = get_transducer_model(params)
+
+ num_param = sum([p.numel() for p in model.parameters()])
+ logging.info(f"Number of model parameters: {num_param}")
+
+ checkpoints = load_checkpoint_if_available(params=params, model=model)
+
+ model.to(device)
+ if world_size > 1:
+ logging.info("Using DDP")
+ model = DDP(model, device_ids=[rank])
+ model.device = device
+
+ optimizer = Noam(
+ model.parameters(),
+ model_size=params.attention_dim,
+ factor=params.lr_factor,
+ warm_step=params.warm_step,
+ weight_decay=params.weight_decay,
+ )
+
+ if checkpoints and "optimizer" in checkpoints:
+ logging.info("Loading optimizer state dict")
+ optimizer.load_state_dict(checkpoints["optimizer"])
+
+ librispeech = LibriSpeechAsrDataModule(args)
+
+ train_cuts = librispeech.train_clean_100_cuts()
+ if params.full_libri:
+ train_cuts += librispeech.train_clean_360_cuts()
+ train_cuts += librispeech.train_other_500_cuts()
+
+ def remove_short_and_long_utt(c: Cut):
+ # Keep only utterances with duration between 1 second and 20 seconds
+ return 1.0 <= c.duration <= 20.0
+
+ num_in_total = len(train_cuts)
+
+ train_cuts = train_cuts.filter(remove_short_and_long_utt)
+
+ num_left = len(train_cuts)
+ num_removed = num_in_total - num_left
+ removed_percent = num_removed / num_in_total * 100
+
+ logging.info(f"Before removing short and long utterances: {num_in_total}")
+ logging.info(f"After removing short and long utterances: {num_left}")
+ logging.info(f"Removed {num_removed} utterances ({removed_percent:.5f}%)")
+
+ train_dl = librispeech.train_dataloaders(train_cuts)
+
+ valid_cuts = librispeech.dev_clean_cuts()
+ valid_cuts += librispeech.dev_other_cuts()
+ valid_dl = librispeech.valid_dataloaders(valid_cuts)
+
+ scan_pessimistic_batches_for_oom(
+ model=model,
+ train_dl=train_dl,
+ optimizer=optimizer,
+ sp=sp,
+ params=params,
+ )
+
+ for epoch in range(params.start_epoch, params.num_epochs):
+ train_dl.sampler.set_epoch(epoch)
+
+ cur_lr = optimizer._rate
+ if tb_writer is not None:
+ tb_writer.add_scalar(
+ "train/learning_rate", cur_lr, params.batch_idx_train
+ )
+ tb_writer.add_scalar("train/epoch", epoch, params.batch_idx_train)
+
+ if rank == 0:
+ logging.info("epoch {}, learning rate {}".format(epoch, cur_lr))
+
+ params.cur_epoch = epoch
+
+ train_one_epoch(
+ params=params,
+ model=model,
+ optimizer=optimizer,
+ sp=sp,
+ train_dl=train_dl,
+ valid_dl=valid_dl,
+ tb_writer=tb_writer,
+ world_size=world_size,
+ )
+
+ save_checkpoint(
+ params=params,
+ model=model,
+ optimizer=optimizer,
+ rank=rank,
+ )
+
+ logging.info("Done!")
+
+ if world_size > 1:
+ torch.distributed.barrier()
+ cleanup_dist()
+
+
+def scan_pessimistic_batches_for_oom(
+ model: nn.Module,
+ train_dl: torch.utils.data.DataLoader,
+ optimizer: torch.optim.Optimizer,
+ sp: spm.SentencePieceProcessor,
+ params: AttributeDict,
+):
+ from lhotse.dataset import find_pessimistic_batches
+
+ logging.info(
+ "Sanity check -- see if any of the batches in epoch 0 would cause OOM."
+ )
+ batches, crit_values = find_pessimistic_batches(train_dl.sampler)
+ for criterion, cuts in batches.items():
+ batch = train_dl.dataset[cuts]
+ try:
+ optimizer.zero_grad()
+ loss, _ = compute_loss(
+ params=params,
+ model=model,
+ sp=sp,
+ batch=batch,
+ is_training=True,
+ )
+ loss.backward()
+ clip_grad_norm_(model.parameters(), 5.0, 2.0)
+ optimizer.step()
+ except RuntimeError as e:
+ if "CUDA out of memory" in str(e):
+ logging.error(
+ "Your GPU ran out of memory with the current "
+ "max_duration setting. We recommend decreasing "
+ "max_duration and trying again.\n"
+ f"Failing criterion: {criterion} "
+ f"(={crit_values[criterion]}) ..."
+ )
+ raise
+
+
+def main():
+ parser = get_parser()
+ LibriSpeechAsrDataModule.add_arguments(parser)
+ args = parser.parse_args()
+ args.exp_dir = Path(args.exp_dir)
+
+ world_size = args.world_size
+ assert world_size >= 1
+ if world_size > 1:
+ mp.spawn(run, args=(world_size, args), nprocs=world_size, join=True)
+ else:
+ run(rank=0, world_size=1, args=args)
+
+
+torch.set_num_threads(1)
+torch.set_num_interop_threads(1)
+
+if __name__ == "__main__":
+ main()
diff --git a/egs/librispeech/ASR/transducer/transformer.py b/egs/librispeech/ASR/transducer/transformer.py
new file mode 100644
index 000000000..814290264
--- /dev/null
+++ b/egs/librispeech/ASR/transducer/transformer.py
@@ -0,0 +1,429 @@
+# 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 Optional, Tuple
+
+import torch
+import torch.nn as nn
+from encoder_interface import EncoderInterface
+from subsampling import Conv2dSubsampling, VggSubsampling
+
+from icefall.utils import make_pad_mask
+
+
+class Transformer(EncoderInterface):
+ def __init__(
+ self,
+ num_features: int,
+ output_dim: int,
+ subsampling_factor: int = 4,
+ d_model: int = 256,
+ nhead: int = 4,
+ dim_feedforward: int = 2048,
+ num_encoder_layers: int = 12,
+ dropout: float = 0.1,
+ normalize_before: bool = True,
+ vgg_frontend: bool = False,
+ use_feat_batchnorm: bool = False,
+ ) -> None:
+ """
+ Args:
+ num_features:
+ The input dimension of the model.
+ output_dim:
+ 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.
+ num_encoder_layers:
+ Number of encoder layers.
+ dropout:
+ Dropout in encoder.
+ 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.
+ """
+ super().__init__()
+ self.use_feat_batchnorm = use_feat_batchnorm
+ if use_feat_batchnorm:
+ self.feat_batchnorm = nn.BatchNorm1d(num_features)
+
+ self.num_features = num_features
+ self.output_dim = output_dim
+ 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_features)
+ # 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_features -> 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, output_dim)
+ )
+
+ def forward(
+ self, x: torch.Tensor, x_lens: torch.Tensor
+ ) -> Tuple[torch.Tensor, torch.Tensor]:
+ """
+ Args:
+ x:
+ The input tensor. Its shape is (batch_size, seq_len, feature_dim).
+ x_lens:
+ A tensor of shape (batch_size,) containing the number of frames in
+ `x` before padding.
+ Returns:
+ Return a tuple containing 2 tensors:
+ - logits, its shape is (batch_size, output_seq_len, output_dim)
+ - logit_lens, a tensor of shape (batch_size,) containing the number
+ of frames in `logits` before padding.
+ """
+ if 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)
+
+ x = self.encoder_embed(x)
+ x = self.encoder_pos(x)
+ x = x.permute(1, 0, 2) # (N, T, C) -> (T, N, C)
+
+ # Caution: We assume the subsampling factor is 4!
+ lengths = ((x_lens - 1) // 2 - 1) // 2
+ assert x.size(0) == lengths.max().item()
+
+ mask = make_pad_mask(lengths)
+ x = self.encoder(x, src_key_padding_mask=mask) # (T, N, C)
+
+ logits = self.encoder_output_layer(x)
+ logits = logits.permute(1, 0, 2) # (T, N, C) ->(N, T, C)
+
+ return logits, lengths
+
+
+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
+
+
+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)
diff --git a/egs/librispeech/ASR/transducer_lstm/README.md b/egs/librispeech/ASR/transducer_lstm/README.md
new file mode 100644
index 000000000..38c3d2bfd
--- /dev/null
+++ b/egs/librispeech/ASR/transducer_lstm/README.md
@@ -0,0 +1,19 @@
+## Introduction
+
+The encoder consists of LSTM layers in this folder. You can use the
+following command to start the training:
+
+```bash
+cd egs/librispeech/ASR
+
+export CUDA_VISIBLE_DEVICES="0,1,2"
+
+./transducer_lstm/train.py \
+ --world-size 3 \
+ --num-epochs 30 \
+ --start-epoch 0 \
+ --exp-dir transducer_lstm/exp \
+ --full-libri 1 \
+ --max-duration 300 \
+ --lr-factor 3
+```
diff --git a/egs/librispeech/ASR/transducer_lstm/asr_datamodule.py b/egs/librispeech/ASR/transducer_lstm/asr_datamodule.py
new file mode 120000
index 000000000..07f39b451
--- /dev/null
+++ b/egs/librispeech/ASR/transducer_lstm/asr_datamodule.py
@@ -0,0 +1 @@
+../transducer/asr_datamodule.py
\ No newline at end of file
diff --git a/egs/librispeech/ASR/transducer_lstm/beam_search.py b/egs/librispeech/ASR/transducer_lstm/beam_search.py
new file mode 100644
index 000000000..013e065be
--- /dev/null
+++ b/egs/librispeech/ASR/transducer_lstm/beam_search.py
@@ -0,0 +1,212 @@
+# 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 dataclasses import dataclass
+from typing import Dict, List, Optional, Tuple
+
+import torch
+from model import Transducer
+
+
+def greedy_search(model: Transducer, encoder_out: torch.Tensor) -> List[int]:
+ """
+ Args:
+ model:
+ An instance of `Transducer`.
+ encoder_out:
+ A tensor of shape (N, T, C) from the encoder. Support only N==1 for now.
+ Returns:
+ Return the decoded result.
+ """
+ assert encoder_out.ndim == 3
+
+ # support only batch_size == 1 for now
+ assert encoder_out.size(0) == 1, encoder_out.size(0)
+ blank_id = model.decoder.blank_id
+ device = model.device
+
+ sos = torch.tensor([blank_id], device=device).reshape(1, 1)
+ decoder_out, (h, c) = model.decoder(sos)
+ T = encoder_out.size(1)
+ t = 0
+ hyp = []
+ max_u = 1000 # terminate after this number of steps
+ u = 0
+
+ while t < T and u < max_u:
+ # fmt: off
+ current_encoder_out = encoder_out[:, t:t+1, :]
+ # fmt: on
+ logits = model.joiner(current_encoder_out, decoder_out)
+ # logits is (1, 1, 1, vocab_size)
+
+ log_prob = logits.log_softmax(dim=-1)
+ # log_prob is (1, 1, 1, vocab_size)
+ # TODO: Use logits.argmax()
+ y = log_prob.argmax()
+ if y != blank_id:
+ hyp.append(y.item())
+ y = y.reshape(1, 1)
+ decoder_out, (h, c) = model.decoder(y, (h, c))
+ u += 1
+ else:
+ t += 1
+
+ return hyp
+
+
+@dataclass
+class Hypothesis:
+ ys: List[int] # the predicted sequences so far
+ log_prob: float # The log prob of ys
+
+ # Optional decoder state. We assume it is LSTM for now,
+ # so the state is a tuple (h, c)
+ decoder_state: Optional[Tuple[torch.Tensor, torch.Tensor]] = None
+
+
+def beam_search(
+ model: Transducer,
+ encoder_out: torch.Tensor,
+ beam: int = 5,
+) -> List[int]:
+ """
+ It implements Algorithm 1 in https://arxiv.org/pdf/1211.3711.pdf
+
+ espnet/nets/beam_search_transducer.py#L247 is used as a reference.
+
+ Args:
+ model:
+ An instance of `Transducer`.
+ encoder_out:
+ A tensor of shape (N, T, C) from the encoder. Support only N==1 for now.
+ beam:
+ Beam size.
+ Returns:
+ Return the decoded result.
+ """
+ assert encoder_out.ndim == 3
+
+ # support only batch_size == 1 for now
+ assert encoder_out.size(0) == 1, encoder_out.size(0)
+ blank_id = model.decoder.blank_id
+ sos_id = model.decoder.sos_id
+ device = model.device
+
+ sos = torch.tensor([blank_id], device=device).reshape(1, 1)
+ decoder_out, (h, c) = model.decoder(sos)
+ T = encoder_out.size(1)
+ t = 0
+ B = [Hypothesis(ys=[blank_id], log_prob=0.0, decoder_state=None)]
+ max_u = 20000 # terminate after this number of steps
+ u = 0
+
+ cache: Dict[
+ str, Tuple[torch.Tensor, Tuple[torch.Tensor, torch.Tensor]]
+ ] = {}
+
+ while t < T and u < max_u:
+ # fmt: off
+ current_encoder_out = encoder_out[:, t:t+1, :]
+ # fmt: on
+ A = B
+ B = []
+ # for hyp in A:
+ # for h in A:
+ # if h.ys == hyp.ys[:-1]:
+ # # update the score of hyp
+ # decoder_input = torch.tensor(
+ # [h.ys[-1]], device=device
+ # ).reshape(1, 1)
+ # decoder_out, _ = model.decoder(
+ # decoder_input, h.decoder_state
+ # )
+ # logits = model.joiner(current_encoder_out, decoder_out)
+ # log_prob = logits.log_softmax(dim=-1)
+ # log_prob = log_prob.squeeze()
+ # hyp.log_prob += h.log_prob + log_prob[hyp.ys[-1]].item()
+
+ while u < max_u:
+ y_star = max(A, key=lambda hyp: hyp.log_prob)
+ A.remove(y_star)
+
+ # Note: y_star.ys is unhashable, i.e., cannot be used
+ # as a key into a dict
+ cached_key = "_".join(map(str, y_star.ys))
+
+ if cached_key not in cache:
+ decoder_input = torch.tensor(
+ [y_star.ys[-1]], device=device
+ ).reshape(1, 1)
+
+ decoder_out, decoder_state = model.decoder(
+ decoder_input,
+ y_star.decoder_state,
+ )
+ cache[cached_key] = (decoder_out, decoder_state)
+ else:
+ decoder_out, decoder_state = cache[cached_key]
+
+ logits = model.joiner(current_encoder_out, decoder_out)
+ log_prob = logits.log_softmax(dim=-1)
+ # log_prob is (1, 1, 1, vocab_size)
+ log_prob = log_prob.squeeze()
+ # Now log_prob is (vocab_size,)
+
+ # If we choose blank here, add the new hypothesis to B.
+ # Otherwise, add the new hypothesis to A
+
+ # First, choose blank
+ skip_log_prob = log_prob[blank_id]
+ new_y_star_log_prob = y_star.log_prob + skip_log_prob.item()
+
+ # ys[:] returns a copy of ys
+ new_y_star = Hypothesis(
+ ys=y_star.ys[:],
+ log_prob=new_y_star_log_prob,
+ # Caution: Use y_star.decoder_state here
+ decoder_state=y_star.decoder_state,
+ )
+ B.append(new_y_star)
+
+ # Second, choose other labels
+ for i, v in enumerate(log_prob.tolist()):
+ if i in (blank_id, sos_id):
+ continue
+ new_ys = y_star.ys + [i]
+ new_log_prob = y_star.log_prob + v
+ new_hyp = Hypothesis(
+ ys=new_ys,
+ log_prob=new_log_prob,
+ decoder_state=decoder_state,
+ )
+ A.append(new_hyp)
+ u += 1
+ # check whether B contains more than "beam" elements more probable
+ # than the most probable in A
+ A_most_probable = max(A, key=lambda hyp: hyp.log_prob)
+ B = sorted(
+ [hyp for hyp in B if hyp.log_prob > A_most_probable.log_prob],
+ key=lambda hyp: hyp.log_prob,
+ reverse=True,
+ )
+ if len(B) >= beam:
+ B = B[:beam]
+ break
+ t += 1
+ best_hyp = max(B, key=lambda hyp: hyp.log_prob / len(hyp.ys[1:]))
+ ys = best_hyp.ys[1:] # [1:] to remove the blank
+ return ys
diff --git a/egs/librispeech/ASR/transducer_lstm/decode.py b/egs/librispeech/ASR/transducer_lstm/decode.py
new file mode 100755
index 000000000..18ae5234c
--- /dev/null
+++ b/egs/librispeech/ASR/transducer_lstm/decode.py
@@ -0,0 +1,457 @@
+#!/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.
+"""
+Usage:
+(1) greedy search
+./transducer_lstm/decode.py \
+ --epoch 14 \
+ --avg 7 \
+ --exp-dir ./transducer_lstm/exp \
+ --max-duration 100 \
+ --decoding-method greedy_search
+(2) beam search
+
+./transducer_lstm/decode.py \
+ --epoch 14 \
+ --avg 7 \
+ --exp-dir ./transducer_lstm/exp \
+ --max-duration 100 \
+ --decoding-method beam_search \
+ --beam-size 8
+"""
+
+
+import argparse
+import logging
+from collections import defaultdict
+from pathlib import Path
+from typing import Dict, List, Tuple
+
+import sentencepiece as spm
+import torch
+import torch.nn as nn
+from asr_datamodule import LibriSpeechAsrDataModule
+from beam_search import beam_search, greedy_search
+from decoder import Decoder
+from encoder import LstmEncoder
+from joiner import Joiner
+from model import Transducer
+
+from icefall.checkpoint import average_checkpoints, load_checkpoint
+from icefall.env import get_env_info
+from icefall.utils import (
+ AttributeDict,
+ setup_logger,
+ store_transcripts,
+ write_error_stats,
+)
+
+
+def get_parser():
+ parser = argparse.ArgumentParser(
+ formatter_class=argparse.ArgumentDefaultsHelpFormatter
+ )
+
+ parser.add_argument(
+ "--epoch",
+ type=int,
+ default=77,
+ help="It specifies the checkpoint to use for decoding."
+ "Note: Epoch counts from 0.",
+ )
+ parser.add_argument(
+ "--avg",
+ type=int,
+ default=55,
+ help="Number of checkpoints to average. Automatically select "
+ "consecutive checkpoints before the checkpoint specified by "
+ "'--epoch'. ",
+ )
+
+ parser.add_argument(
+ "--exp-dir",
+ type=str,
+ default="transducer_lstm/exp",
+ help="The experiment dir",
+ )
+
+ parser.add_argument(
+ "--bpe-model",
+ type=str,
+ default="data/lang_bpe_500/bpe.model",
+ help="Path to the BPE model",
+ )
+
+ parser.add_argument(
+ "--decoding-method",
+ type=str,
+ default="greedy_search",
+ help="""Possible values are:
+ - greedy_search
+ - beam_search
+ """,
+ )
+
+ parser.add_argument(
+ "--beam-size",
+ type=int,
+ default=5,
+ help="Used only when --decoding-method is beam_search",
+ )
+
+ return parser
+
+
+def get_params() -> AttributeDict:
+ params = AttributeDict(
+ {
+ # parameters for conformer
+ "feature_dim": 80,
+ "encoder_out_dim": 512,
+ "subsampling_factor": 4,
+ "encoder_hidden_size": 1024,
+ "num_encoder_layers": 4,
+ "proj_size": 512,
+ "vgg_frontend": False,
+ # decoder params
+ "decoder_embedding_dim": 1024,
+ "num_decoder_layers": 4,
+ "decoder_hidden_dim": 512,
+ "env_info": get_env_info(),
+ }
+ )
+ return params
+
+
+def get_encoder_model(params: AttributeDict):
+ encoder = LstmEncoder(
+ num_features=params.feature_dim,
+ hidden_size=params.encoder_hidden_size,
+ output_dim=params.encoder_out_dim,
+ subsampling_factor=params.subsampling_factor,
+ num_encoder_layers=params.num_encoder_layers,
+ vgg_frontend=params.vgg_frontend,
+ )
+ return encoder
+
+
+def get_decoder_model(params: AttributeDict):
+ decoder = Decoder(
+ vocab_size=params.vocab_size,
+ embedding_dim=params.decoder_embedding_dim,
+ blank_id=params.blank_id,
+ sos_id=params.sos_id,
+ num_layers=params.num_decoder_layers,
+ hidden_dim=params.decoder_hidden_dim,
+ output_dim=params.encoder_out_dim,
+ )
+ return decoder
+
+
+def get_joiner_model(params: AttributeDict):
+ joiner = Joiner(
+ input_dim=params.encoder_out_dim,
+ output_dim=params.vocab_size,
+ )
+ return joiner
+
+
+def get_transducer_model(params: AttributeDict):
+ encoder = get_encoder_model(params)
+ decoder = get_decoder_model(params)
+ joiner = get_joiner_model(params)
+
+ model = Transducer(
+ encoder=encoder,
+ decoder=decoder,
+ joiner=joiner,
+ )
+ return model
+
+
+def decode_one_batch(
+ params: AttributeDict,
+ model: nn.Module,
+ sp: spm.SentencePieceProcessor,
+ batch: dict,
+) -> Dict[str, List[List[str]]]:
+ """Decode one batch and return the result in a dict. The dict has the
+ following format:
+
+ - key: It indicates the setting used for decoding. For example,
+ if greedy_search is used, it would be "greedy_search"
+ If beam search with a beam size of 7 is used, it would be
+ "beam_7"
+ - value: It contains the decoding result. `len(value)` equals to
+ batch size. `value[i]` is the decoding result for the i-th
+ utterance in the given batch.
+ Args:
+ params:
+ It's the return value of :func:`get_params`.
+ model:
+ The neural model.
+ sp:
+ The BPE model.
+ batch:
+ It is the return value from iterating
+ `lhotse.dataset.K2SpeechRecognitionDataset`. See its documentation
+ for the format of the `batch`.
+ Returns:
+ Return the decoding result. See above description for the format of
+ the returned dict.
+ """
+ device = model.device
+ feature = batch["inputs"]
+ assert feature.ndim == 3
+
+ feature = feature.to(device)
+ # at entry, feature is (N, T, C)
+
+ supervisions = batch["supervisions"]
+ feature_lens = supervisions["num_frames"].to(device)
+
+ encoder_out, encoder_out_lens = model.encoder(
+ x=feature, x_lens=feature_lens
+ )
+ hyps = []
+ batch_size = encoder_out.size(0)
+
+ for i in range(batch_size):
+ # fmt: off
+ encoder_out_i = encoder_out[i:i+1, :encoder_out_lens[i]]
+ # fmt: on
+ if params.decoding_method == "greedy_search":
+ hyp = greedy_search(model=model, encoder_out=encoder_out_i)
+ elif params.decoding_method == "beam_search":
+ hyp = beam_search(
+ model=model, encoder_out=encoder_out_i, beam=params.beam_size
+ )
+ else:
+ raise ValueError(
+ f"Unsupported decoding method: {params.decoding_method}"
+ )
+ hyps.append(sp.decode(hyp).split())
+
+ if params.decoding_method == "greedy_search":
+ return {"greedy_search": hyps}
+ else:
+ return {f"beam_{params.beam_size}": hyps}
+
+
+def decode_dataset(
+ dl: torch.utils.data.DataLoader,
+ params: AttributeDict,
+ model: nn.Module,
+ sp: spm.SentencePieceProcessor,
+) -> Dict[str, List[Tuple[List[str], List[str]]]]:
+ """Decode dataset.
+
+ Args:
+ dl:
+ PyTorch's dataloader containing the dataset to decode.
+ params:
+ It is returned by :func:`get_params`.
+ model:
+ The neural model.
+ sp:
+ The BPE model.
+ Returns:
+ Return a dict, whose key may be "greedy_search" if greedy search
+ is used, or it may be "beam_7" if beam size of 7 is used.
+ Its value is a list of tuples. Each tuple contains two elements:
+ The first is the reference transcript, and the second is the
+ predicted result.
+ """
+ num_cuts = 0
+
+ try:
+ num_batches = len(dl)
+ except TypeError:
+ num_batches = "?"
+
+ if params.decoding_method == "greedy_search":
+ log_interval = 100
+ else:
+ log_interval = 2
+
+ results = defaultdict(list)
+ for batch_idx, batch in enumerate(dl):
+ texts = batch["supervisions"]["text"]
+
+ hyps_dict = decode_one_batch(
+ params=params,
+ model=model,
+ sp=sp,
+ batch=batch,
+ )
+
+ for name, hyps in hyps_dict.items():
+ this_batch = []
+ assert len(hyps) == len(texts)
+ for hyp_words, ref_text in zip(hyps, texts):
+ ref_words = ref_text.split()
+ this_batch.append((ref_words, hyp_words))
+
+ results[name].extend(this_batch)
+
+ num_cuts += len(texts)
+
+ if batch_idx % log_interval == 0:
+ batch_str = f"{batch_idx}/{num_batches}"
+
+ logging.info(
+ f"batch {batch_str}, cuts processed until now is {num_cuts}"
+ )
+ return results
+
+
+def save_results(
+ params: AttributeDict,
+ test_set_name: str,
+ results_dict: Dict[str, List[Tuple[List[int], List[int]]]],
+):
+ test_set_wers = dict()
+ for key, results in results_dict.items():
+ recog_path = (
+ params.res_dir / f"recogs-{test_set_name}-{key}-{params.suffix}.txt"
+ )
+ store_transcripts(filename=recog_path, texts=results)
+ logging.info(f"The transcripts are stored in {recog_path}")
+
+ # The following prints out WERs, per-word error statistics and aligned
+ # ref/hyp pairs.
+ errs_filename = (
+ params.res_dir / f"errs-{test_set_name}-{key}-{params.suffix}.txt"
+ )
+ with open(errs_filename, "w") as f:
+ wer = write_error_stats(
+ f, f"{test_set_name}-{key}", results, enable_log=True
+ )
+ test_set_wers[key] = wer
+
+ logging.info("Wrote detailed error stats to {}".format(errs_filename))
+
+ test_set_wers = sorted(test_set_wers.items(), key=lambda x: x[1])
+ errs_info = (
+ params.res_dir
+ / f"wer-summary-{test_set_name}-{key}-{params.suffix}.txt"
+ )
+ with open(errs_info, "w") as f:
+ print("settings\tWER", file=f)
+ for key, val in test_set_wers:
+ print("{}\t{}".format(key, val), file=f)
+
+ s = "\nFor {}, WER of different settings are:\n".format(test_set_name)
+ note = "\tbest for {}".format(test_set_name)
+ for key, val in test_set_wers:
+ s += "{}\t{}{}\n".format(key, val, note)
+ note = ""
+ logging.info(s)
+
+
+@torch.no_grad()
+def main():
+ parser = get_parser()
+ LibriSpeechAsrDataModule.add_arguments(parser)
+ args = parser.parse_args()
+ args.exp_dir = Path(args.exp_dir)
+
+ params = get_params()
+ params.update(vars(args))
+
+ assert params.decoding_method in ("greedy_search", "beam_search")
+ params.res_dir = params.exp_dir / params.decoding_method
+
+ params.suffix = f"epoch-{params.epoch}-avg-{params.avg}"
+ if params.decoding_method == "beam_search":
+ params.suffix += f"-beam-{params.beam_size}"
+
+ setup_logger(f"{params.res_dir}/log-decode-{params.suffix}")
+ logging.info("Decoding started")
+
+ device = torch.device("cpu")
+ if torch.cuda.is_available():
+ device = torch.device("cuda", 0)
+
+ logging.info(f"Device: {device}")
+
+ sp = spm.SentencePieceProcessor()
+ sp.load(params.bpe_model)
+
+ # and are defined in local/train_bpe_model.py
+ params.blank_id = sp.piece_to_id("")
+ params.sos_id = sp.piece_to_id("")
+ params.vocab_size = sp.get_piece_size()
+
+ logging.info(params)
+
+ logging.info("About to create model")
+ model = get_transducer_model(params)
+
+ 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.to(device)
+ model.load_state_dict(average_checkpoints(filenames, device=device))
+
+ model.to(device)
+ model.eval()
+ model.device = device
+
+ num_param = sum([p.numel() for p in model.parameters()])
+ logging.info(f"Number of model parameters: {num_param}")
+
+ librispeech = LibriSpeechAsrDataModule(args)
+
+ test_clean_cuts = librispeech.test_clean_cuts()
+ test_other_cuts = librispeech.test_other_cuts()
+
+ test_clean_dl = librispeech.test_dataloaders(test_clean_cuts)
+ test_other_dl = librispeech.test_dataloaders(test_other_cuts)
+
+ test_sets = ["test-clean", "test-other"]
+ test_dl = [test_clean_dl, test_other_dl]
+
+ for test_set, test_dl in zip(test_sets, test_dl):
+ results_dict = decode_dataset(
+ dl=test_dl,
+ params=params,
+ model=model,
+ sp=sp,
+ )
+
+ save_results(
+ params=params,
+ test_set_name=test_set,
+ results_dict=results_dict,
+ )
+
+ logging.info("Done!")
+
+
+torch.set_num_threads(1)
+torch.set_num_interop_threads(1)
+
+if __name__ == "__main__":
+ main()
diff --git a/egs/librispeech/ASR/transducer_lstm/decoder.py b/egs/librispeech/ASR/transducer_lstm/decoder.py
new file mode 100644
index 000000000..2f6bf4c07
--- /dev/null
+++ b/egs/librispeech/ASR/transducer_lstm/decoder.py
@@ -0,0 +1,101 @@
+# 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 typing import Optional, Tuple
+
+import torch
+import torch.nn as nn
+
+
+# TODO(fangjun): Support switching between LSTM and GRU
+class Decoder(nn.Module):
+ def __init__(
+ self,
+ vocab_size: int,
+ embedding_dim: int,
+ blank_id: int,
+ sos_id: int,
+ num_layers: int,
+ hidden_dim: int,
+ output_dim: int,
+ embedding_dropout: float = 0.0,
+ rnn_dropout: float = 0.0,
+ ):
+ """
+ Args:
+ vocab_size:
+ Number of tokens of the modeling unit including blank.
+ embedding_dim:
+ Dimension of the input embedding.
+ blank_id:
+ The ID of the blank symbol.
+ sos_id:
+ The ID of the SOS symbol.
+ num_layers:
+ Number of LSTM layers.
+ hidden_dim:
+ Hidden dimension of LSTM layers.
+ output_dim:
+ Output dimension of the decoder.
+ embedding_dropout:
+ Dropout rate for the embedding layer.
+ rnn_dropout:
+ Dropout for LSTM layers.
+ """
+ super().__init__()
+ self.embedding = nn.Embedding(
+ num_embeddings=vocab_size,
+ embedding_dim=embedding_dim,
+ padding_idx=blank_id,
+ )
+ self.embedding_dropout = nn.Dropout(embedding_dropout)
+ # TODO(fangjun): Use layer normalized LSTM
+ self.rnn = nn.LSTM(
+ input_size=embedding_dim,
+ hidden_size=hidden_dim,
+ num_layers=num_layers,
+ batch_first=True,
+ dropout=rnn_dropout,
+ )
+ self.blank_id = blank_id
+ self.sos_id = sos_id
+ self.output_linear = nn.Linear(hidden_dim, output_dim)
+
+ def forward(
+ self,
+ y: torch.Tensor,
+ states: Optional[Tuple[torch.Tensor, torch.Tensor]] = None,
+ ) -> Tuple[torch.Tensor, Tuple[torch.Tensor, torch.Tensor]]:
+ """
+ Args:
+ y:
+ A 2-D tensor of shape (N, U) with BOS prepended.
+ states:
+ A tuple of two tensors containing the states information of
+ LSTM layers in this decoder.
+ Returns:
+ Return a tuple containing:
+
+ - rnn_output, a tensor of shape (N, U, C)
+ - (h, c), containing the state information for LSTM layers.
+ Both are of shape (num_layers, N, C)
+ """
+ embeding_out = self.embedding(y)
+ embeding_out = self.embedding_dropout(embeding_out)
+ rnn_out, (h, c) = self.rnn(embeding_out, states)
+ out = self.output_linear(rnn_out)
+
+ return out, (h, c)
diff --git a/egs/librispeech/ASR/transducer_lstm/encoder.py b/egs/librispeech/ASR/transducer_lstm/encoder.py
new file mode 100644
index 000000000..860a84bb1
--- /dev/null
+++ b/egs/librispeech/ASR/transducer_lstm/encoder.py
@@ -0,0 +1,115 @@
+# 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 typing import Tuple
+
+import torch
+import torch.nn as nn
+from encoder_interface import EncoderInterface
+from subsampling import Conv2dSubsampling, VggSubsampling
+from torch.nn.utils.rnn import pack_padded_sequence, pad_packed_sequence
+
+
+class LstmEncoder(EncoderInterface):
+ def __init__(
+ self,
+ num_features: int,
+ hidden_size: int,
+ output_dim: int,
+ subsampling_factor: int = 4,
+ num_encoder_layers: int = 12,
+ dropout: float = 0.1,
+ vgg_frontend: bool = False,
+ proj_size: int = 0,
+ ):
+ super().__init__()
+ real_hidden_size = proj_size if proj_size > 0 else hidden_size
+ assert (
+ subsampling_factor == 4
+ ), "Only subsampling_factor==4 is supported at present"
+
+ # self.encoder_embed converts the input of shape (N, T, num_features)
+ # 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_features -> d_model
+ if vgg_frontend:
+ self.encoder_embed = VggSubsampling(num_features, real_hidden_size)
+ else:
+ self.encoder_embed = Conv2dSubsampling(
+ num_features, real_hidden_size
+ )
+
+ self.rnn = nn.LSTM(
+ input_size=hidden_size,
+ hidden_size=hidden_size,
+ num_layers=num_encoder_layers,
+ bias=True,
+ proj_size=proj_size,
+ batch_first=True,
+ dropout=dropout,
+ bidirectional=False,
+ )
+
+ self.encoder_output_layer = nn.Sequential(
+ nn.Dropout(p=dropout),
+ nn.Linear(real_hidden_size, output_dim),
+ )
+
+ def forward(
+ self, x: torch.Tensor, x_lens: torch.Tensor
+ ) -> Tuple[torch.Tensor, torch.Tensor]:
+ """
+ Args:
+ x:
+ The input tensor. Its shape is (batch_size, seq_len, feature_dim).
+ x_lens:
+ A tensor of shape (batch_size,) containing the number of frames in
+ `x` before padding.
+ Returns:
+ Return a tuple containing 2 tensors:
+ - logits, its shape is (batch_size, output_seq_len, output_dim)
+ - logit_lens, a tensor of shape (batch_size,) containing the number
+ of frames in `logits` before padding.
+ """
+ x = self.encoder_embed(x)
+
+ # Caution: We assume the subsampling factor is 4!
+ lengths = ((x_lens - 1) // 2 - 1) // 2
+ assert x.size(1) == lengths.max().item(), (
+ x.size(1),
+ lengths.max(),
+ )
+
+ if False:
+ # It is commented out as DPP complains that not all parameters are
+ # used. Need more checks later for the reason.
+ #
+ # Caution: We assume the dataloader returns utterances with
+ # duration being sorted in decreasing order
+ packed_x = pack_padded_sequence(
+ input=x,
+ lengths=lengths.cpu(),
+ batch_first=True,
+ enforce_sorted=True,
+ )
+
+ packed_rnn_out, _ = self.rnn(packed_x)
+ rnn_out, _ = pad_packed_sequence(packed_x, batch_first=True)
+ else:
+ rnn_out, _ = self.rnn(x)
+
+ logits = self.encoder_output_layer(rnn_out)
+ return logits, lengths
diff --git a/egs/librispeech/ASR/transducer_lstm/encoder_interface.py b/egs/librispeech/ASR/transducer_lstm/encoder_interface.py
new file mode 100644
index 000000000..257facce4
--- /dev/null
+++ b/egs/librispeech/ASR/transducer_lstm/encoder_interface.py
@@ -0,0 +1,43 @@
+# 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 typing import Tuple
+
+import torch
+import torch.nn as nn
+
+
+class EncoderInterface(nn.Module):
+ def forward(
+ self, x: torch.Tensor, x_lens: torch.Tensor
+ ) -> Tuple[torch.Tensor, torch.Tensor]:
+ """
+ Args:
+ x:
+ A tensor of shape (batch_size, input_seq_len, num_features)
+ containing the input features.
+ x_lens:
+ A tensor of shape (batch_size,) containing the number of frames
+ in `x` before padding.
+ Returns:
+ Return a tuple containing two tensors:
+ - encoder_out, a tensor of (batch_size, out_seq_len, output_dim)
+ containing unnormalized probabilities, i.e., the output of a
+ linear layer.
+ - encoder_out_lens, a tensor of shape (batch_size,) containing
+ the number of frames in `encoder_out` before padding.
+ """
+ raise NotImplementedError("Please implement it in a subclass")
diff --git a/egs/librispeech/ASR/transducer_lstm/joiner.py b/egs/librispeech/ASR/transducer_lstm/joiner.py
new file mode 100644
index 000000000..0422f8a6f
--- /dev/null
+++ b/egs/librispeech/ASR/transducer_lstm/joiner.py
@@ -0,0 +1,55 @@
+# 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
+import torch.nn.functional as F
+
+
+class Joiner(nn.Module):
+ def __init__(self, input_dim: int, output_dim: int):
+ super().__init__()
+
+ self.output_linear = nn.Linear(input_dim, output_dim)
+
+ def forward(
+ self, encoder_out: torch.Tensor, decoder_out: torch.Tensor
+ ) -> torch.Tensor:
+ """
+ Args:
+ encoder_out:
+ Output from the encoder. Its shape is (N, T, C).
+ decoder_out:
+ Output from the decoder. Its shape is (N, U, C).
+ Returns:
+ Return a tensor of shape (N, T, U, C).
+ """
+ assert encoder_out.ndim == decoder_out.ndim == 3
+ assert encoder_out.size(0) == decoder_out.size(0)
+ assert encoder_out.size(2) == decoder_out.size(2)
+
+ encoder_out = encoder_out.unsqueeze(2)
+ # Now encoder_out is (N, T, 1, C)
+
+ decoder_out = decoder_out.unsqueeze(1)
+ # Now decoder_out is (N, 1, U, C)
+
+ logit = encoder_out + decoder_out
+ logit = F.relu(logit)
+
+ output = self.output_linear(logit)
+
+ return output
diff --git a/egs/librispeech/ASR/transducer_lstm/model.py b/egs/librispeech/ASR/transducer_lstm/model.py
new file mode 100644
index 000000000..8a4d3ca69
--- /dev/null
+++ b/egs/librispeech/ASR/transducer_lstm/model.py
@@ -0,0 +1,127 @@
+# 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.
+
+"""
+Note we use `rnnt_loss` from torchaudio, which exists only in
+torchaudio >= v0.10.0. It also means you have to use torch >= v1.10.0
+"""
+import k2
+import torch
+import torch.nn as nn
+import torchaudio
+import torchaudio.functional
+from encoder_interface import EncoderInterface
+
+from icefall.utils import add_sos
+
+assert hasattr(torchaudio.functional, "rnnt_loss"), (
+ f"Current torchaudio version: {torchaudio.__version__}\n"
+ "Please install a version >= 0.10.0"
+)
+
+
+class Transducer(nn.Module):
+ """It implements https://arxiv.org/pdf/1211.3711.pdf
+ "Sequence Transduction with Recurrent Neural Networks"
+ """
+
+ def __init__(
+ self,
+ encoder: EncoderInterface,
+ decoder: nn.Module,
+ joiner: nn.Module,
+ ):
+ """
+ Args:
+ encoder:
+ It is the transcription network in the paper. Its accepts
+ two inputs: `x` of (N, T, C) and `x_lens` of shape (N,).
+ It returns two tensors: `logits` of shape (N, T, C) and
+ `logit_lens` of shape (N,).
+ decoder:
+ It is the prediction network in the paper. Its input shape
+ is (N, U) and its output shape is (N, U, C). It should contain
+ two attributes: `blank_id` and `sos_id`.
+ joiner:
+ It has two inputs with shapes: (N, T, C) and (N, U, C). Its
+ output shape is (N, T, U, C). Note that its output contains
+ unnormalized probs, i.e., not processed by log-softmax.
+ """
+ super().__init__()
+ assert isinstance(encoder, EncoderInterface)
+ assert hasattr(decoder, "blank_id")
+ assert hasattr(decoder, "sos_id")
+
+ self.encoder = encoder
+ self.decoder = decoder
+ self.joiner = joiner
+
+ def forward(
+ self,
+ x: torch.Tensor,
+ x_lens: torch.Tensor,
+ y: k2.RaggedTensor,
+ ) -> torch.Tensor:
+ """
+ Args:
+ x:
+ A 3-D tensor of shape (N, T, C).
+ x_lens:
+ A 1-D tensor of shape (N,). It contains the number of frames in `x`
+ before padding.
+ y:
+ A ragged tensor with 2 axes [utt][label]. It contains labels of each
+ utterance.
+ Returns:
+ Return the transducer loss.
+ """
+ assert x.ndim == 3, x.shape
+ assert x_lens.ndim == 1, x_lens.shape
+ assert y.num_axes == 2, y.num_axes
+
+ assert x.size(0) == x_lens.size(0) == y.dim0
+
+ encoder_out, x_lens = self.encoder(x, x_lens)
+ assert torch.all(x_lens > 0)
+
+ # Now for the decoder, i.e., the prediction network
+ row_splits = y.shape.row_splits(1)
+ y_lens = row_splits[1:] - row_splits[:-1]
+
+ blank_id = self.decoder.blank_id
+ sos_id = self.decoder.sos_id
+ sos_y = add_sos(y, sos_id=sos_id)
+
+ sos_y_padded = sos_y.pad(mode="constant", padding_value=blank_id)
+
+ decoder_out, _ = self.decoder(sos_y_padded)
+
+ logits = self.joiner(encoder_out, decoder_out)
+
+ # rnnt_loss requires 0 padded targets
+ # Note: y does not start with SOS
+ y_padded = y.pad(mode="constant", padding_value=0)
+
+ loss = torchaudio.functional.rnnt_loss(
+ logits=logits,
+ targets=y_padded,
+ logit_lengths=x_lens,
+ target_lengths=y_lens,
+ blank=blank_id,
+ reduction="sum",
+ )
+
+ return loss
diff --git a/egs/librispeech/ASR/transducer_lstm/noam.py b/egs/librispeech/ASR/transducer_lstm/noam.py
new file mode 100644
index 000000000..e46bf35fb
--- /dev/null
+++ b/egs/librispeech/ASR/transducer_lstm/noam.py
@@ -0,0 +1,104 @@
+# 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 torch
+
+
+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)
diff --git a/egs/librispeech/ASR/transducer_lstm/subsampling.py b/egs/librispeech/ASR/transducer_lstm/subsampling.py
new file mode 120000
index 000000000..73068da26
--- /dev/null
+++ b/egs/librispeech/ASR/transducer_lstm/subsampling.py
@@ -0,0 +1 @@
+../transducer/subsampling.py
\ No newline at end of file
diff --git a/egs/librispeech/ASR/transducer_lstm/test_encoder.py b/egs/librispeech/ASR/transducer_lstm/test_encoder.py
new file mode 100755
index 000000000..cad5f1148
--- /dev/null
+++ b/egs/librispeech/ASR/transducer_lstm/test_encoder.py
@@ -0,0 +1,48 @@
+#!/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.
+"""
+To run this file, do:
+
+ cd icefall/egs/librispeech/ASR
+ python ./transducer_lstm/test_encoder.py
+"""
+
+from encoder import LstmEncoder
+
+
+def test_encoder():
+ encoder = LstmEncoder(
+ num_features=80,
+ hidden_size=1024,
+ proj_size=512,
+ output_dim=512,
+ subsampling_factor=4,
+ num_encoder_layers=12,
+ )
+ num_params = sum(p.numel() for p in encoder.parameters() if p.requires_grad)
+ print(num_params)
+ # 93979284
+ # 66427392
+
+
+def main():
+ test_encoder()
+
+
+if __name__ == "__main__":
+ main()
diff --git a/egs/librispeech/ASR/transducer_lstm/train.py b/egs/librispeech/ASR/transducer_lstm/train.py
new file mode 100755
index 000000000..62e9b5b12
--- /dev/null
+++ b/egs/librispeech/ASR/transducer_lstm/train.py
@@ -0,0 +1,738 @@
+#!/usr/bin/env python3
+# Copyright 2021 Xiaomi Corp. (authors: Fangjun Kuang,
+# Wei Kang
+# 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.
+
+"""
+Usage:
+
+export CUDA_VISIBLE_DEVICES="0,1,2"
+
+./transducer_lstm/train.py \
+ --world-size 3 \
+ --num-epochs 30 \
+ --start-epoch 0 \
+ --exp-dir transducer_lstm/exp \
+ --full-libri 1 \
+ --max-duration 400 \
+ --lr-factor 3
+"""
+
+
+import argparse
+import logging
+from pathlib import Path
+from shutil import copyfile
+from typing import Optional, Tuple
+
+import k2
+import sentencepiece as spm
+import torch
+import torch.multiprocessing as mp
+import torch.nn as nn
+from asr_datamodule import LibriSpeechAsrDataModule
+from decoder import Decoder
+from encoder import LstmEncoder
+from joiner import Joiner
+from lhotse.cut import Cut
+from lhotse.utils import fix_random_seed
+from model import Transducer
+from noam import Noam
+from torch import Tensor
+from torch.nn.parallel import DistributedDataParallel as DDP
+from torch.nn.utils import clip_grad_norm_
+from torch.utils.tensorboard import SummaryWriter
+
+from icefall.checkpoint import load_checkpoint
+from icefall.checkpoint import save_checkpoint as save_checkpoint_impl
+from icefall.dist import cleanup_dist, setup_dist
+from icefall.env import get_env_info
+from icefall.utils import AttributeDict, MetricsTracker, setup_logger, str2bool
+
+
+def get_parser():
+ parser = argparse.ArgumentParser(
+ formatter_class=argparse.ArgumentDefaultsHelpFormatter
+ )
+
+ parser.add_argument(
+ "--world-size",
+ type=int,
+ default=1,
+ help="Number of GPUs for DDP training.",
+ )
+
+ parser.add_argument(
+ "--master-port",
+ type=int,
+ default=12354,
+ help="Master port to use for DDP training.",
+ )
+
+ parser.add_argument(
+ "--tensorboard",
+ type=str2bool,
+ default=True,
+ help="Should various information be logged in tensorboard.",
+ )
+
+ parser.add_argument(
+ "--num-epochs",
+ type=int,
+ default=30,
+ help="Number of epochs to train.",
+ )
+
+ parser.add_argument(
+ "--start-epoch",
+ type=int,
+ default=0,
+ help="""Resume training from from this epoch.
+ If it is positive, it will load checkpoint from
+ transducer_lstm/exp/epoch-{start_epoch-1}.pt
+ """,
+ )
+
+ parser.add_argument(
+ "--exp-dir",
+ type=str,
+ default="transducer_lstm/exp",
+ help="""The experiment dir.
+ It specifies the directory where all training related
+ files, e.g., checkpoints, log, etc, are saved
+ """,
+ )
+
+ parser.add_argument(
+ "--bpe-model",
+ type=str,
+ default="data/lang_bpe_500/bpe.model",
+ help="Path to the BPE model",
+ )
+
+ parser.add_argument(
+ "--lr-factor",
+ type=float,
+ default=3.0,
+ help="The lr_factor for Noam optimizer",
+ )
+
+ return parser
+
+
+def get_params() -> AttributeDict:
+ """Return a dict containing training parameters.
+
+ All training related parameters that are not passed from the commandline
+ are saved in the variable `params`.
+
+ Commandline options are merged into `params` after they are parsed, so
+ you can also access them via `params`.
+
+ Explanation of options saved in `params`:
+
+ - best_train_loss: Best training loss so far. It is used to select
+ the model that has the lowest training loss. It is
+ updated during the training.
+
+ - best_valid_loss: Best validation loss so far. It is used to select
+ the model that has the lowest validation loss. It is
+ updated during the training.
+
+ - best_train_epoch: It is the epoch that has the best training loss.
+
+ - best_valid_epoch: It is the epoch that has the best validation loss.
+
+ - batch_idx_train: Used to writing statistics to tensorboard. It
+ contains number of batches trained so far across
+ epochs.
+
+ - log_interval: Print training loss if batch_idx % log_interval` is 0
+
+ - reset_interval: Reset statistics if batch_idx % reset_interval is 0
+
+ - valid_interval: Run validation if batch_idx % valid_interval is 0
+
+ - feature_dim: The model input dim. It has to match the one used
+ in computing features.
+
+ - subsampling_factor: The subsampling factor for the model.
+
+ - use_feat_batchnorm: Whether to do batch normalization for the
+ input features.
+
+ - attention_dim: Hidden dim for multi-head attention model.
+
+ - num_decoder_layers: Number of decoder layer of transformer decoder.
+
+ - weight_decay: The weight_decay for the optimizer.
+
+ - warm_step: The warm_step for Noam optimizer.
+ """
+ params = AttributeDict(
+ {
+ "best_train_loss": float("inf"),
+ "best_valid_loss": float("inf"),
+ "best_train_epoch": -1,
+ "best_valid_epoch": -1,
+ "batch_idx_train": 0,
+ "log_interval": 50,
+ "reset_interval": 200,
+ "valid_interval": 3000, # For the 100h subset, use 800
+ # parameters for conformer
+ "feature_dim": 80,
+ "encoder_out_dim": 512,
+ "subsampling_factor": 4,
+ "encoder_hidden_size": 1024,
+ "num_encoder_layers": 4,
+ "proj_size": 512,
+ "vgg_frontend": False,
+ # decoder params
+ "decoder_embedding_dim": 1024,
+ "num_decoder_layers": 4,
+ "decoder_hidden_dim": 512,
+ # parameters for Noam
+ "weight_decay": 1e-6,
+ "warm_step": 80000, # For the 100h subset, use 8k
+ "env_info": get_env_info(),
+ }
+ )
+
+ return params
+
+
+def get_encoder_model(params: AttributeDict):
+ encoder = LstmEncoder(
+ num_features=params.feature_dim,
+ hidden_size=params.encoder_hidden_size,
+ output_dim=params.encoder_out_dim,
+ subsampling_factor=params.subsampling_factor,
+ num_encoder_layers=params.num_encoder_layers,
+ vgg_frontend=params.vgg_frontend,
+ )
+ return encoder
+
+
+def get_decoder_model(params: AttributeDict):
+ decoder = Decoder(
+ vocab_size=params.vocab_size,
+ embedding_dim=params.decoder_embedding_dim,
+ blank_id=params.blank_id,
+ sos_id=params.sos_id,
+ num_layers=params.num_decoder_layers,
+ hidden_dim=params.decoder_hidden_dim,
+ output_dim=params.encoder_out_dim,
+ )
+ return decoder
+
+
+def get_joiner_model(params: AttributeDict):
+ joiner = Joiner(
+ input_dim=params.encoder_out_dim,
+ output_dim=params.vocab_size,
+ )
+ return joiner
+
+
+def get_transducer_model(params: AttributeDict):
+ encoder = get_encoder_model(params)
+ decoder = get_decoder_model(params)
+ joiner = get_joiner_model(params)
+
+ model = Transducer(
+ encoder=encoder,
+ decoder=decoder,
+ joiner=joiner,
+ )
+ return model
+
+
+def load_checkpoint_if_available(
+ params: AttributeDict,
+ model: nn.Module,
+ optimizer: Optional[torch.optim.Optimizer] = None,
+ scheduler: Optional[torch.optim.lr_scheduler._LRScheduler] = None,
+) -> None:
+ """Load checkpoint from file.
+
+ If params.start_epoch is positive, it will load the checkpoint from
+ `params.start_epoch - 1`. Otherwise, this function does nothing.
+
+ Apart from loading state dict for `model`, `optimizer` and `scheduler`,
+ it also updates `best_train_epoch`, `best_train_loss`, `best_valid_epoch`,
+ and `best_valid_loss` in `params`.
+
+ Args:
+ params:
+ The return value of :func:`get_params`.
+ model:
+ The training model.
+ optimizer:
+ The optimizer that we are using.
+ scheduler:
+ The learning rate scheduler we are using.
+ Returns:
+ Return None.
+ """
+ if params.start_epoch <= 0:
+ return
+
+ filename = params.exp_dir / f"epoch-{params.start_epoch-1}.pt"
+ saved_params = load_checkpoint(
+ filename,
+ model=model,
+ optimizer=optimizer,
+ scheduler=scheduler,
+ )
+
+ keys = [
+ "best_train_epoch",
+ "best_valid_epoch",
+ "batch_idx_train",
+ "best_train_loss",
+ "best_valid_loss",
+ ]
+ for k in keys:
+ params[k] = saved_params[k]
+
+ return saved_params
+
+
+def save_checkpoint(
+ params: AttributeDict,
+ model: nn.Module,
+ optimizer: Optional[torch.optim.Optimizer] = None,
+ scheduler: Optional[torch.optim.lr_scheduler._LRScheduler] = None,
+ rank: int = 0,
+) -> None:
+ """Save model, optimizer, scheduler and training stats to file.
+
+ Args:
+ params:
+ It is returned by :func:`get_params`.
+ model:
+ The training model.
+ """
+ if rank != 0:
+ return
+ filename = params.exp_dir / f"epoch-{params.cur_epoch}.pt"
+ save_checkpoint_impl(
+ filename=filename,
+ model=model,
+ params=params,
+ optimizer=optimizer,
+ scheduler=scheduler,
+ rank=rank,
+ )
+
+ if params.best_train_epoch == params.cur_epoch:
+ best_train_filename = params.exp_dir / "best-train-loss.pt"
+ copyfile(src=filename, dst=best_train_filename)
+
+ if params.best_valid_epoch == params.cur_epoch:
+ best_valid_filename = params.exp_dir / "best-valid-loss.pt"
+ copyfile(src=filename, dst=best_valid_filename)
+
+
+def compute_loss(
+ params: AttributeDict,
+ model: nn.Module,
+ sp: spm.SentencePieceProcessor,
+ batch: dict,
+ is_training: bool,
+) -> Tuple[Tensor, MetricsTracker]:
+ """
+ Compute CTC loss given the model and its inputs.
+
+ Args:
+ params:
+ Parameters for training. See :func:`get_params`.
+ model:
+ The model for training. It is an instance of Conformer in our case.
+ batch:
+ A batch of data. See `lhotse.dataset.K2SpeechRecognitionDataset()`
+ for the content in it.
+ is_training:
+ True for training. False for validation. When it is True, this
+ function enables autograd during computation; when it is False, it
+ disables autograd.
+ """
+ device = model.device
+ feature = batch["inputs"]
+ # at entry, feature is (N, T, C)
+ assert feature.ndim == 3
+ feature = feature.to(device)
+
+ supervisions = batch["supervisions"]
+ feature_lens = supervisions["num_frames"].to(device)
+
+ texts = batch["supervisions"]["text"]
+ y = sp.encode(texts, out_type=int)
+ y = k2.RaggedTensor(y).to(device)
+
+ with torch.set_grad_enabled(is_training):
+ loss = model(x=feature, x_lens=feature_lens, y=y)
+
+ assert loss.requires_grad == is_training
+
+ info = MetricsTracker()
+ info["frames"] = (feature_lens // params.subsampling_factor).sum().item()
+
+ # Note: We use reduction=sum while computing the loss.
+ info["loss"] = loss.detach().cpu().item()
+
+ return loss, info
+
+
+def compute_validation_loss(
+ params: AttributeDict,
+ model: nn.Module,
+ sp: spm.SentencePieceProcessor,
+ valid_dl: torch.utils.data.DataLoader,
+ world_size: int = 1,
+) -> MetricsTracker:
+ """Run the validation process."""
+ model.eval()
+
+ tot_loss = MetricsTracker()
+
+ for batch_idx, batch in enumerate(valid_dl):
+ loss, loss_info = compute_loss(
+ params=params,
+ model=model,
+ sp=sp,
+ batch=batch,
+ is_training=False,
+ )
+ assert loss.requires_grad is False
+ tot_loss = tot_loss + loss_info
+
+ if world_size > 1:
+ tot_loss.reduce(loss.device)
+
+ loss_value = tot_loss["loss"] / tot_loss["frames"]
+ if loss_value < params.best_valid_loss:
+ params.best_valid_epoch = params.cur_epoch
+ params.best_valid_loss = loss_value
+
+ return tot_loss
+
+
+def train_one_epoch(
+ params: AttributeDict,
+ model: nn.Module,
+ optimizer: torch.optim.Optimizer,
+ sp: spm.SentencePieceProcessor,
+ train_dl: torch.utils.data.DataLoader,
+ valid_dl: torch.utils.data.DataLoader,
+ tb_writer: Optional[SummaryWriter] = None,
+ world_size: int = 1,
+) -> None:
+ """Train the model for one epoch.
+
+ The training loss from the mean of all frames is saved in
+ `params.train_loss`. It runs the validation process every
+ `params.valid_interval` batches.
+
+ Args:
+ params:
+ It is returned by :func:`get_params`.
+ model:
+ The model for training.
+ optimizer:
+ The optimizer we are using.
+ train_dl:
+ Dataloader for the training dataset.
+ valid_dl:
+ Dataloader for the validation dataset.
+ tb_writer:
+ Writer to write log messages to tensorboard.
+ world_size:
+ Number of nodes in DDP training. If it is 1, DDP is disabled.
+ """
+ model.train()
+
+ tot_loss = MetricsTracker()
+
+ for batch_idx, batch in enumerate(train_dl):
+ params.batch_idx_train += 1
+ batch_size = len(batch["supervisions"]["text"])
+
+ loss, loss_info = compute_loss(
+ params=params,
+ model=model,
+ sp=sp,
+ batch=batch,
+ is_training=True,
+ )
+ # summary stats
+ tot_loss = (tot_loss * (1 - 1 / params.reset_interval)) + loss_info
+
+ # NOTE: We use reduction==sum and loss is computed over utterances
+ # in the batch and there is no normalization to it so far.
+
+ optimizer.zero_grad()
+ loss.backward()
+ clip_grad_norm_(model.parameters(), 5.0, 2.0)
+ optimizer.step()
+
+ if batch_idx % params.log_interval == 0:
+ logging.info(
+ f"Epoch {params.cur_epoch}, "
+ f"batch {batch_idx}, loss[{loss_info}], "
+ f"tot_loss[{tot_loss}], batch size: {batch_size}"
+ )
+
+ if batch_idx % params.log_interval == 0:
+
+ if tb_writer is not None:
+ loss_info.write_summary(
+ tb_writer, "train/current_", params.batch_idx_train
+ )
+ tot_loss.write_summary(
+ tb_writer, "train/tot_", params.batch_idx_train
+ )
+
+ if batch_idx > 0 and batch_idx % params.valid_interval == 0:
+ logging.info("Computing validation loss")
+ valid_info = compute_validation_loss(
+ params=params,
+ model=model,
+ sp=sp,
+ valid_dl=valid_dl,
+ world_size=world_size,
+ )
+ model.train()
+ logging.info(f"Epoch {params.cur_epoch}, validation: {valid_info}")
+ if tb_writer is not None:
+ valid_info.write_summary(
+ tb_writer, "train/valid_", params.batch_idx_train
+ )
+
+ loss_value = tot_loss["loss"] / tot_loss["frames"]
+ params.train_loss = loss_value
+ if params.train_loss < params.best_train_loss:
+ params.best_train_epoch = params.cur_epoch
+ params.best_train_loss = params.train_loss
+
+
+def run(rank, world_size, args):
+ """
+ Args:
+ rank:
+ It is a value between 0 and `world_size-1`, which is
+ passed automatically by `mp.spawn()` in :func:`main`.
+ The node with rank 0 is responsible for saving checkpoint.
+ world_size:
+ Number of GPUs for DDP training.
+ args:
+ The return value of get_parser().parse_args()
+ """
+ params = get_params()
+ params.update(vars(args))
+ if params.full_libri is False:
+ params.valid_interval = 800
+ params.warm_step = 8000
+
+ fix_random_seed(42)
+ if world_size > 1:
+ setup_dist(rank, world_size, params.master_port)
+
+ setup_logger(f"{params.exp_dir}/log/log-train")
+ logging.info("Training started")
+
+ if args.tensorboard and rank == 0:
+ tb_writer = SummaryWriter(log_dir=f"{params.exp_dir}/tensorboard")
+ else:
+ tb_writer = None
+
+ device = torch.device("cpu")
+ if torch.cuda.is_available():
+ device = torch.device("cuda", rank)
+ logging.info(f"Device: {device}")
+
+ sp = spm.SentencePieceProcessor()
+ sp.load(params.bpe_model)
+
+ # and are defined in local/train_bpe_model.py
+ params.blank_id = sp.piece_to_id("")
+ params.sos_id = sp.piece_to_id("")
+ params.vocab_size = sp.get_piece_size()
+
+ logging.info(params)
+
+ logging.info("About to create model")
+ model = get_transducer_model(params)
+
+ checkpoints = load_checkpoint_if_available(params=params, model=model)
+
+ num_param = sum([p.numel() for p in model.parameters() if p.requires_grad])
+ logging.info(f"Number of model parameters: {num_param}")
+
+ model.to(device)
+ if world_size > 1:
+ logging.info("Using DDP")
+ model = DDP(model, device_ids=[rank])
+ model.device = device
+
+ optimizer = Noam(
+ model.parameters(),
+ model_size=params.encoder_hidden_size,
+ factor=params.lr_factor,
+ warm_step=params.warm_step,
+ weight_decay=params.weight_decay,
+ )
+
+ if checkpoints and "optimizer" in checkpoints:
+ logging.info("Loading optimizer state dict")
+ optimizer.load_state_dict(checkpoints["optimizer"])
+
+ librispeech = LibriSpeechAsrDataModule(args)
+
+ train_cuts = librispeech.train_clean_100_cuts()
+ if params.full_libri:
+ train_cuts += librispeech.train_clean_360_cuts()
+ train_cuts += librispeech.train_other_500_cuts()
+
+ def remove_short_and_long_utt(c: Cut):
+ # Keep only utterances with duration between 1 second and 20 seconds
+ return 1.0 <= c.duration <= 20.0
+
+ num_in_total = len(train_cuts)
+
+ train_cuts = train_cuts.filter(remove_short_and_long_utt)
+
+ num_left = len(train_cuts)
+ num_removed = num_in_total - num_left
+ removed_percent = num_removed / num_in_total * 100
+
+ logging.info(f"Before removing short and long utterances: {num_in_total}")
+ logging.info(f"After removing short and long utterances: {num_left}")
+ logging.info(f"Removed {num_removed} utterances ({removed_percent:.5f}%)")
+
+ train_dl = librispeech.train_dataloaders(train_cuts)
+
+ valid_cuts = librispeech.dev_clean_cuts()
+ valid_cuts += librispeech.dev_other_cuts()
+ valid_dl = librispeech.valid_dataloaders(valid_cuts)
+
+ scan_pessimistic_batches_for_oom(
+ model=model,
+ train_dl=train_dl,
+ optimizer=optimizer,
+ sp=sp,
+ params=params,
+ )
+
+ for epoch in range(params.start_epoch, params.num_epochs):
+ train_dl.sampler.set_epoch(epoch)
+
+ cur_lr = optimizer._rate
+ if tb_writer is not None:
+ tb_writer.add_scalar(
+ "train/learning_rate", cur_lr, params.batch_idx_train
+ )
+ tb_writer.add_scalar("train/epoch", epoch, params.batch_idx_train)
+
+ if rank == 0:
+ logging.info("epoch {}, learning rate {}".format(epoch, cur_lr))
+
+ params.cur_epoch = epoch
+
+ train_one_epoch(
+ params=params,
+ model=model,
+ optimizer=optimizer,
+ sp=sp,
+ train_dl=train_dl,
+ valid_dl=valid_dl,
+ tb_writer=tb_writer,
+ world_size=world_size,
+ )
+
+ save_checkpoint(
+ params=params,
+ model=model,
+ optimizer=optimizer,
+ rank=rank,
+ )
+
+ logging.info("Done!")
+
+ if world_size > 1:
+ torch.distributed.barrier()
+ cleanup_dist()
+
+
+def scan_pessimistic_batches_for_oom(
+ model: nn.Module,
+ train_dl: torch.utils.data.DataLoader,
+ optimizer: torch.optim.Optimizer,
+ sp: spm.SentencePieceProcessor,
+ params: AttributeDict,
+):
+ from lhotse.dataset import find_pessimistic_batches
+
+ logging.info(
+ "Sanity check -- see if any of the batches in epoch 0 would cause OOM."
+ )
+ batches, crit_values = find_pessimistic_batches(train_dl.sampler)
+ for criterion, cuts in batches.items():
+ batch = train_dl.dataset[cuts]
+ try:
+ optimizer.zero_grad()
+ loss, _ = compute_loss(
+ params=params,
+ model=model,
+ sp=sp,
+ batch=batch,
+ is_training=True,
+ )
+ loss.backward()
+ clip_grad_norm_(model.parameters(), 5.0, 2.0)
+ optimizer.step()
+ except RuntimeError as e:
+ if "CUDA out of memory" in str(e):
+ logging.error(
+ "Your GPU ran out of memory with the current "
+ "max_duration setting. We recommend decreasing "
+ "max_duration and trying again.\n"
+ f"Failing criterion: {criterion} "
+ f"(={crit_values[criterion]}) ..."
+ )
+ raise
+
+
+def main():
+ parser = get_parser()
+ LibriSpeechAsrDataModule.add_arguments(parser)
+ args = parser.parse_args()
+ args.exp_dir = Path(args.exp_dir)
+
+ world_size = args.world_size
+ assert world_size >= 1
+ if world_size > 1:
+ mp.spawn(run, args=(world_size, args), nprocs=world_size, join=True)
+ else:
+ run(rank=0, world_size=1, args=args)
+
+
+torch.set_num_threads(1)
+torch.set_num_interop_threads(1)
+
+if __name__ == "__main__":
+ main()
diff --git a/egs/librispeech/ASR/transducer_stateless/README.md b/egs/librispeech/ASR/transducer_stateless/README.md
new file mode 100644
index 000000000..964bddfab
--- /dev/null
+++ b/egs/librispeech/ASR/transducer_stateless/README.md
@@ -0,0 +1,22 @@
+## Introduction
+
+The decoder, i.e., the prediction network, is from
+https://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=9054419
+(Rnn-Transducer with Stateless Prediction Network)
+
+You can use the following command to start the training:
+
+```bash
+cd egs/librispeech/ASR
+
+export CUDA_VISIBLE_DEVICES="0,1,2,3"
+
+./transducer_stateless/train.py \
+ --world-size 4 \
+ --num-epochs 30 \
+ --start-epoch 0 \
+ --exp-dir transducer_stateless/exp \
+ --full-libri 1 \
+ --max-duration 250 \
+ --lr-factor 2.5
+```
diff --git a/egs/librispeech/ASR/transducer_stateless/__init__.py b/egs/librispeech/ASR/transducer_stateless/__init__.py
new file mode 100644
index 000000000..e69de29bb
diff --git a/egs/librispeech/ASR/transducer_stateless/asr_datamodule.py b/egs/librispeech/ASR/transducer_stateless/asr_datamodule.py
new file mode 120000
index 000000000..07f39b451
--- /dev/null
+++ b/egs/librispeech/ASR/transducer_stateless/asr_datamodule.py
@@ -0,0 +1 @@
+../transducer/asr_datamodule.py
\ No newline at end of file
diff --git a/egs/librispeech/ASR/transducer_stateless/beam_search.py b/egs/librispeech/ASR/transducer_stateless/beam_search.py
new file mode 100644
index 000000000..013e065be
--- /dev/null
+++ b/egs/librispeech/ASR/transducer_stateless/beam_search.py
@@ -0,0 +1,212 @@
+# 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 dataclasses import dataclass
+from typing import Dict, List, Optional, Tuple
+
+import torch
+from model import Transducer
+
+
+def greedy_search(model: Transducer, encoder_out: torch.Tensor) -> List[int]:
+ """
+ Args:
+ model:
+ An instance of `Transducer`.
+ encoder_out:
+ A tensor of shape (N, T, C) from the encoder. Support only N==1 for now.
+ Returns:
+ Return the decoded result.
+ """
+ assert encoder_out.ndim == 3
+
+ # support only batch_size == 1 for now
+ assert encoder_out.size(0) == 1, encoder_out.size(0)
+ blank_id = model.decoder.blank_id
+ device = model.device
+
+ sos = torch.tensor([blank_id], device=device).reshape(1, 1)
+ decoder_out, (h, c) = model.decoder(sos)
+ T = encoder_out.size(1)
+ t = 0
+ hyp = []
+ max_u = 1000 # terminate after this number of steps
+ u = 0
+
+ while t < T and u < max_u:
+ # fmt: off
+ current_encoder_out = encoder_out[:, t:t+1, :]
+ # fmt: on
+ logits = model.joiner(current_encoder_out, decoder_out)
+ # logits is (1, 1, 1, vocab_size)
+
+ log_prob = logits.log_softmax(dim=-1)
+ # log_prob is (1, 1, 1, vocab_size)
+ # TODO: Use logits.argmax()
+ y = log_prob.argmax()
+ if y != blank_id:
+ hyp.append(y.item())
+ y = y.reshape(1, 1)
+ decoder_out, (h, c) = model.decoder(y, (h, c))
+ u += 1
+ else:
+ t += 1
+
+ return hyp
+
+
+@dataclass
+class Hypothesis:
+ ys: List[int] # the predicted sequences so far
+ log_prob: float # The log prob of ys
+
+ # Optional decoder state. We assume it is LSTM for now,
+ # so the state is a tuple (h, c)
+ decoder_state: Optional[Tuple[torch.Tensor, torch.Tensor]] = None
+
+
+def beam_search(
+ model: Transducer,
+ encoder_out: torch.Tensor,
+ beam: int = 5,
+) -> List[int]:
+ """
+ It implements Algorithm 1 in https://arxiv.org/pdf/1211.3711.pdf
+
+ espnet/nets/beam_search_transducer.py#L247 is used as a reference.
+
+ Args:
+ model:
+ An instance of `Transducer`.
+ encoder_out:
+ A tensor of shape (N, T, C) from the encoder. Support only N==1 for now.
+ beam:
+ Beam size.
+ Returns:
+ Return the decoded result.
+ """
+ assert encoder_out.ndim == 3
+
+ # support only batch_size == 1 for now
+ assert encoder_out.size(0) == 1, encoder_out.size(0)
+ blank_id = model.decoder.blank_id
+ sos_id = model.decoder.sos_id
+ device = model.device
+
+ sos = torch.tensor([blank_id], device=device).reshape(1, 1)
+ decoder_out, (h, c) = model.decoder(sos)
+ T = encoder_out.size(1)
+ t = 0
+ B = [Hypothesis(ys=[blank_id], log_prob=0.0, decoder_state=None)]
+ max_u = 20000 # terminate after this number of steps
+ u = 0
+
+ cache: Dict[
+ str, Tuple[torch.Tensor, Tuple[torch.Tensor, torch.Tensor]]
+ ] = {}
+
+ while t < T and u < max_u:
+ # fmt: off
+ current_encoder_out = encoder_out[:, t:t+1, :]
+ # fmt: on
+ A = B
+ B = []
+ # for hyp in A:
+ # for h in A:
+ # if h.ys == hyp.ys[:-1]:
+ # # update the score of hyp
+ # decoder_input = torch.tensor(
+ # [h.ys[-1]], device=device
+ # ).reshape(1, 1)
+ # decoder_out, _ = model.decoder(
+ # decoder_input, h.decoder_state
+ # )
+ # logits = model.joiner(current_encoder_out, decoder_out)
+ # log_prob = logits.log_softmax(dim=-1)
+ # log_prob = log_prob.squeeze()
+ # hyp.log_prob += h.log_prob + log_prob[hyp.ys[-1]].item()
+
+ while u < max_u:
+ y_star = max(A, key=lambda hyp: hyp.log_prob)
+ A.remove(y_star)
+
+ # Note: y_star.ys is unhashable, i.e., cannot be used
+ # as a key into a dict
+ cached_key = "_".join(map(str, y_star.ys))
+
+ if cached_key not in cache:
+ decoder_input = torch.tensor(
+ [y_star.ys[-1]], device=device
+ ).reshape(1, 1)
+
+ decoder_out, decoder_state = model.decoder(
+ decoder_input,
+ y_star.decoder_state,
+ )
+ cache[cached_key] = (decoder_out, decoder_state)
+ else:
+ decoder_out, decoder_state = cache[cached_key]
+
+ logits = model.joiner(current_encoder_out, decoder_out)
+ log_prob = logits.log_softmax(dim=-1)
+ # log_prob is (1, 1, 1, vocab_size)
+ log_prob = log_prob.squeeze()
+ # Now log_prob is (vocab_size,)
+
+ # If we choose blank here, add the new hypothesis to B.
+ # Otherwise, add the new hypothesis to A
+
+ # First, choose blank
+ skip_log_prob = log_prob[blank_id]
+ new_y_star_log_prob = y_star.log_prob + skip_log_prob.item()
+
+ # ys[:] returns a copy of ys
+ new_y_star = Hypothesis(
+ ys=y_star.ys[:],
+ log_prob=new_y_star_log_prob,
+ # Caution: Use y_star.decoder_state here
+ decoder_state=y_star.decoder_state,
+ )
+ B.append(new_y_star)
+
+ # Second, choose other labels
+ for i, v in enumerate(log_prob.tolist()):
+ if i in (blank_id, sos_id):
+ continue
+ new_ys = y_star.ys + [i]
+ new_log_prob = y_star.log_prob + v
+ new_hyp = Hypothesis(
+ ys=new_ys,
+ log_prob=new_log_prob,
+ decoder_state=decoder_state,
+ )
+ A.append(new_hyp)
+ u += 1
+ # check whether B contains more than "beam" elements more probable
+ # than the most probable in A
+ A_most_probable = max(A, key=lambda hyp: hyp.log_prob)
+ B = sorted(
+ [hyp for hyp in B if hyp.log_prob > A_most_probable.log_prob],
+ key=lambda hyp: hyp.log_prob,
+ reverse=True,
+ )
+ if len(B) >= beam:
+ B = B[:beam]
+ break
+ t += 1
+ best_hyp = max(B, key=lambda hyp: hyp.log_prob / len(hyp.ys[1:]))
+ ys = best_hyp.ys[1:] # [1:] to remove the blank
+ return ys
diff --git a/egs/librispeech/ASR/transducer_stateless/conformer.py b/egs/librispeech/ASR/transducer_stateless/conformer.py
new file mode 100644
index 000000000..22977b835
--- /dev/null
+++ b/egs/librispeech/ASR/transducer_stateless/conformer.py
@@ -0,0 +1,922 @@
+#!/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
+
+import torch
+from torch import Tensor, nn
+from transducer.transformer import Transformer
+
+from icefall.utils import make_pad_mask
+
+
+class Conformer(Transformer):
+ """
+ Args:
+ num_features (int): Number of input features
+ output_dim (int): Number of output dimension
+ 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
+ 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,
+ output_dim: int,
+ subsampling_factor: int = 4,
+ d_model: int = 256,
+ nhead: int = 4,
+ dim_feedforward: int = 2048,
+ num_encoder_layers: int = 12,
+ dropout: float = 0.1,
+ cnn_module_kernel: int = 31,
+ normalize_before: bool = True,
+ vgg_frontend: bool = False,
+ use_feat_batchnorm: bool = False,
+ ) -> None:
+ super(Conformer, self).__init__(
+ num_features=num_features,
+ output_dim=output_dim,
+ subsampling_factor=subsampling_factor,
+ d_model=d_model,
+ nhead=nhead,
+ dim_feedforward=dim_feedforward,
+ num_encoder_layers=num_encoder_layers,
+ dropout=dropout,
+ normalize_before=normalize_before,
+ vgg_frontend=vgg_frontend,
+ use_feat_batchnorm=use_feat_batchnorm,
+ )
+
+ self.encoder_pos = RelPositionalEncoding(d_model, dropout)
+
+ encoder_layer = ConformerEncoderLayer(
+ d_model,
+ nhead,
+ dim_feedforward,
+ dropout,
+ cnn_module_kernel,
+ normalize_before,
+ )
+ 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 forward(
+ self, x: torch.Tensor, x_lens: torch.Tensor
+ ) -> Tuple[torch.Tensor, torch.Tensor]:
+ """
+ Args:
+ x:
+ The input tensor. Its shape is (batch_size, seq_len, feature_dim).
+ x_lens:
+ A tensor of shape (batch_size,) containing the number of frames in
+ `x` before padding.
+ Returns:
+ Return a tuple containing 2 tensors:
+ - logits, its shape is (batch_size, output_seq_len, output_dim)
+ - logit_lens, a tensor of shape (batch_size,) containing the number
+ of frames in `logits` before padding.
+ """
+ if 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)
+
+ x = self.encoder_embed(x)
+ x, pos_emb = self.encoder_pos(x)
+ x = x.permute(1, 0, 2) # (N, T, C) -> (T, N, C)
+
+ # Caution: We assume the subsampling factor is 4!
+ lengths = ((x_lens - 1) // 2 - 1) // 2
+ assert x.size(0) == lengths.max().item()
+ mask = make_pad_mask(lengths)
+
+ x = self.encoder(x, pos_emb, src_key_padding_mask=mask) # (T, N, C)
+
+ if self.normalize_before:
+ x = self.after_norm(x)
+
+ logits = self.encoder_output_layer(x)
+ logits = logits.permute(1, 0, 2) # (T, N, C) ->(N, T, C)
+
+ return logits, lengths
+
+
+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,
+ ) -> 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)
+
+ 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))
+ 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 vecotr 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 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
+ ) -> 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.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,
+ )
+ 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) -> Tensor:
+ """Compute convolution module.
+
+ Args:
+ x: Input tensor (#time, batch, channels).
+
+ 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
+ x = self.depthwise_conv(x)
+ x = self.activation(self.norm(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
diff --git a/egs/librispeech/ASR/transducer_stateless/decoder.py b/egs/librispeech/ASR/transducer_stateless/decoder.py
new file mode 100644
index 000000000..9d6b3aaf2
--- /dev/null
+++ b/egs/librispeech/ASR/transducer_stateless/decoder.py
@@ -0,0 +1,65 @@
+# 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 Decoder(nn.Module):
+ """This class implements the stateless decoder from the following paper:
+
+ RNN-transducer with stateless prediction network
+ https://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=9054419
+
+ It removes the recurrent connection from the decoder, i.e., the prediction
+ network.
+
+ TODO: Implement https://arxiv.org/pdf/2109.07513.pdf
+ """
+
+ def __init__(
+ self,
+ vocab_size: int,
+ embedding_dim: int,
+ blank_id: int,
+ ):
+ """
+ Args:
+ vocab_size:
+ Number of tokens of the modeling unit including blank.
+ embedding_dim:
+ Dimension of the input embedding.
+ blank_id:
+ The ID of the blank symbol.
+ """
+ super().__init__()
+ self.embedding = nn.Embedding(
+ num_embeddings=vocab_size,
+ embedding_dim=embedding_dim,
+ padding_idx=blank_id,
+ )
+ self.blank_id = blank_id
+
+ def forward(self, y: torch.Tensor) -> torch.Tensor:
+ """
+ Args:
+ y:
+ A 2-D tensor of shape (N, U) with blank prepended.
+ Returns:
+ Return a tensor of shape (N, U, embedding_dim).
+ """
+ embeding_out = self.embedding(y)
+ return embeding_out
diff --git a/egs/librispeech/ASR/transducer_stateless/encoder_interface.py b/egs/librispeech/ASR/transducer_stateless/encoder_interface.py
new file mode 100644
index 000000000..257facce4
--- /dev/null
+++ b/egs/librispeech/ASR/transducer_stateless/encoder_interface.py
@@ -0,0 +1,43 @@
+# 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 typing import Tuple
+
+import torch
+import torch.nn as nn
+
+
+class EncoderInterface(nn.Module):
+ def forward(
+ self, x: torch.Tensor, x_lens: torch.Tensor
+ ) -> Tuple[torch.Tensor, torch.Tensor]:
+ """
+ Args:
+ x:
+ A tensor of shape (batch_size, input_seq_len, num_features)
+ containing the input features.
+ x_lens:
+ A tensor of shape (batch_size,) containing the number of frames
+ in `x` before padding.
+ Returns:
+ Return a tuple containing two tensors:
+ - encoder_out, a tensor of (batch_size, out_seq_len, output_dim)
+ containing unnormalized probabilities, i.e., the output of a
+ linear layer.
+ - encoder_out_lens, a tensor of shape (batch_size,) containing
+ the number of frames in `encoder_out` before padding.
+ """
+ raise NotImplementedError("Please implement it in a subclass")
diff --git a/egs/librispeech/ASR/transducer_stateless/joiner.py b/egs/librispeech/ASR/transducer_stateless/joiner.py
new file mode 100644
index 000000000..0422f8a6f
--- /dev/null
+++ b/egs/librispeech/ASR/transducer_stateless/joiner.py
@@ -0,0 +1,55 @@
+# 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
+import torch.nn.functional as F
+
+
+class Joiner(nn.Module):
+ def __init__(self, input_dim: int, output_dim: int):
+ super().__init__()
+
+ self.output_linear = nn.Linear(input_dim, output_dim)
+
+ def forward(
+ self, encoder_out: torch.Tensor, decoder_out: torch.Tensor
+ ) -> torch.Tensor:
+ """
+ Args:
+ encoder_out:
+ Output from the encoder. Its shape is (N, T, C).
+ decoder_out:
+ Output from the decoder. Its shape is (N, U, C).
+ Returns:
+ Return a tensor of shape (N, T, U, C).
+ """
+ assert encoder_out.ndim == decoder_out.ndim == 3
+ assert encoder_out.size(0) == decoder_out.size(0)
+ assert encoder_out.size(2) == decoder_out.size(2)
+
+ encoder_out = encoder_out.unsqueeze(2)
+ # Now encoder_out is (N, T, 1, C)
+
+ decoder_out = decoder_out.unsqueeze(1)
+ # Now decoder_out is (N, 1, U, C)
+
+ logit = encoder_out + decoder_out
+ logit = F.relu(logit)
+
+ output = self.output_linear(logit)
+
+ return output
diff --git a/egs/librispeech/ASR/transducer_stateless/model.py b/egs/librispeech/ASR/transducer_stateless/model.py
new file mode 100644
index 000000000..9e6ab167f
--- /dev/null
+++ b/egs/librispeech/ASR/transducer_stateless/model.py
@@ -0,0 +1,125 @@
+# 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.
+
+"""
+Note we use `rnnt_loss` from torchaudio, which exists only in
+torchaudio >= v0.10.0. It also means you have to use torch >= v1.10.0
+"""
+import k2
+import torch
+import torch.nn as nn
+import torchaudio
+import torchaudio.functional
+from encoder_interface import EncoderInterface
+
+from icefall.utils import add_sos
+
+assert hasattr(torchaudio.functional, "rnnt_loss"), (
+ f"Current torchaudio version: {torchaudio.__version__}\n"
+ "Please install a version >= 0.10.0"
+)
+
+
+class Transducer(nn.Module):
+ """It implements https://arxiv.org/pdf/1211.3711.pdf
+ "Sequence Transduction with Recurrent Neural Networks"
+ """
+
+ def __init__(
+ self,
+ encoder: EncoderInterface,
+ decoder: nn.Module,
+ joiner: nn.Module,
+ ):
+ """
+ Args:
+ encoder:
+ It is the transcription network in the paper. Its accepts
+ two inputs: `x` of (N, T, C) and `x_lens` of shape (N,).
+ It returns two tensors: `logits` of shape (N, T, C) and
+ `logit_lens` of shape (N,).
+ decoder:
+ It is the prediction network in the paper. Its input shape
+ is (N, U) and its output shape is (N, U, C). It should contain
+ one attribute: `blank_id`.
+ joiner:
+ It has two inputs with shapes: (N, T, C) and (N, U, C). Its
+ output shape is (N, T, U, C). Note that its output contains
+ unnormalized probs, i.e., not processed by log-softmax.
+ """
+ super().__init__()
+ assert isinstance(encoder, EncoderInterface)
+ assert hasattr(decoder, "blank_id")
+
+ self.encoder = encoder
+ self.decoder = decoder
+ self.joiner = joiner
+
+ def forward(
+ self,
+ x: torch.Tensor,
+ x_lens: torch.Tensor,
+ y: k2.RaggedTensor,
+ ) -> torch.Tensor:
+ """
+ Args:
+ x:
+ A 3-D tensor of shape (N, T, C).
+ x_lens:
+ A 1-D tensor of shape (N,). It contains the number of frames in `x`
+ before padding.
+ y:
+ A ragged tensor with 2 axes [utt][label]. It contains labels of each
+ utterance.
+ Returns:
+ Return the transducer loss.
+ """
+ assert x.ndim == 3, x.shape
+ assert x_lens.ndim == 1, x_lens.shape
+ assert y.num_axes == 2, y.num_axes
+
+ assert x.size(0) == x_lens.size(0) == y.dim0
+
+ encoder_out, x_lens = self.encoder(x, x_lens)
+ assert torch.all(x_lens > 0)
+
+ # Now for the decoder, i.e., the prediction network
+ row_splits = y.shape.row_splits(1)
+ y_lens = row_splits[1:] - row_splits[:-1]
+
+ blank_id = self.decoder.blank_id
+ sos_y = add_sos(y, sos_id=blank_id)
+
+ sos_y_padded = sos_y.pad(mode="constant", padding_value=blank_id)
+
+ decoder_out = self.decoder(sos_y_padded)
+
+ logits = self.joiner(encoder_out, decoder_out)
+
+ # rnnt_loss requires 0 padded targets
+ # Note: y does not start with SOS
+ y_padded = y.pad(mode="constant", padding_value=0)
+
+ loss = torchaudio.functional.rnnt_loss(
+ logits=logits,
+ targets=y_padded,
+ logit_lengths=x_lens,
+ target_lengths=y_lens,
+ blank=blank_id,
+ reduction="sum",
+ )
+
+ return loss
diff --git a/egs/librispeech/ASR/transducer_stateless/subsampling.py b/egs/librispeech/ASR/transducer_stateless/subsampling.py
new file mode 120000
index 000000000..73068da26
--- /dev/null
+++ b/egs/librispeech/ASR/transducer_stateless/subsampling.py
@@ -0,0 +1 @@
+../transducer/subsampling.py
\ No newline at end of file
diff --git a/egs/librispeech/ASR/transducer_stateless/train.py b/egs/librispeech/ASR/transducer_stateless/train.py
new file mode 100755
index 000000000..e20aedf9b
--- /dev/null
+++ b/egs/librispeech/ASR/transducer_stateless/train.py
@@ -0,0 +1,734 @@
+#!/usr/bin/env python3
+# Copyright 2021 Xiaomi Corp. (authors: Fangjun Kuang,
+# Wei Kang
+# 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.
+"""
+Usage:
+
+export CUDA_VISIBLE_DEVICES="0,1,2,3"
+
+./transducer_stateless/train.py \
+ --world-size 4 \
+ --num-epochs 30 \
+ --start-epoch 0 \
+ --exp-dir transducer_stateless/exp \
+ --full-libri 1 \
+ --max-duration 250 \
+ --lr-factor 2.5
+"""
+
+
+import argparse
+import logging
+from pathlib import Path
+from shutil import copyfile
+from typing import Optional, Tuple
+
+import k2
+import sentencepiece as spm
+import torch
+import torch.multiprocessing as mp
+import torch.nn as nn
+from asr_datamodule import LibriSpeechAsrDataModule
+from conformer import Conformer
+from decoder import Decoder
+from joiner import Joiner
+from lhotse.cut import Cut
+from lhotse.utils import fix_random_seed
+from model import Transducer
+from torch import Tensor
+from torch.nn.parallel import DistributedDataParallel as DDP
+from torch.nn.utils import clip_grad_norm_
+from torch.utils.tensorboard import SummaryWriter
+from transformer import Noam
+
+from icefall.checkpoint import load_checkpoint
+from icefall.checkpoint import save_checkpoint as save_checkpoint_impl
+from icefall.dist import cleanup_dist, setup_dist
+from icefall.env import get_env_info
+from icefall.utils import AttributeDict, MetricsTracker, setup_logger, str2bool
+
+
+def get_parser():
+ parser = argparse.ArgumentParser(
+ formatter_class=argparse.ArgumentDefaultsHelpFormatter
+ )
+
+ parser.add_argument(
+ "--world-size",
+ type=int,
+ default=1,
+ help="Number of GPUs for DDP training.",
+ )
+
+ parser.add_argument(
+ "--master-port",
+ type=int,
+ default=12354,
+ help="Master port to use for DDP training.",
+ )
+
+ parser.add_argument(
+ "--tensorboard",
+ type=str2bool,
+ default=True,
+ help="Should various information be logged in tensorboard.",
+ )
+
+ parser.add_argument(
+ "--num-epochs",
+ type=int,
+ default=78,
+ help="Number of epochs to train.",
+ )
+
+ parser.add_argument(
+ "--start-epoch",
+ type=int,
+ default=0,
+ help="""Resume training from from this epoch.
+ If it is positive, it will load checkpoint from
+ transducer_stateless/exp/epoch-{start_epoch-1}.pt
+ """,
+ )
+
+ parser.add_argument(
+ "--exp-dir",
+ type=str,
+ default="transducer_stateless/exp",
+ help="""The experiment dir.
+ It specifies the directory where all training related
+ files, e.g., checkpoints, log, etc, are saved
+ """,
+ )
+
+ parser.add_argument(
+ "--bpe-model",
+ type=str,
+ default="data/lang_bpe_500/bpe.model",
+ help="Path to the BPE model",
+ )
+
+ parser.add_argument(
+ "--lr-factor",
+ type=float,
+ default=5.0,
+ help="The lr_factor for Noam optimizer",
+ )
+
+ return parser
+
+
+def get_params() -> AttributeDict:
+ """Return a dict containing training parameters.
+
+ All training related parameters that are not passed from the commandline
+ are saved in the variable `params`.
+
+ Commandline options are merged into `params` after they are parsed, so
+ you can also access them via `params`.
+
+ Explanation of options saved in `params`:
+
+ - best_train_loss: Best training loss so far. It is used to select
+ the model that has the lowest training loss. It is
+ updated during the training.
+
+ - best_valid_loss: Best validation loss so far. It is used to select
+ the model that has the lowest validation loss. It is
+ updated during the training.
+
+ - best_train_epoch: It is the epoch that has the best training loss.
+
+ - best_valid_epoch: It is the epoch that has the best validation loss.
+
+ - batch_idx_train: Used to writing statistics to tensorboard. It
+ contains number of batches trained so far across
+ epochs.
+
+ - log_interval: Print training loss if batch_idx % log_interval` is 0
+
+ - reset_interval: Reset statistics if batch_idx % reset_interval is 0
+
+ - valid_interval: Run validation if batch_idx % valid_interval is 0
+
+ - feature_dim: The model input dim. It has to match the one used
+ in computing features.
+
+ - subsampling_factor: The subsampling factor for the model.
+
+ - use_feat_batchnorm: Whether to do batch normalization for the
+ input features.
+
+ - attention_dim: Hidden dim for multi-head attention model.
+
+ - num_decoder_layers: Number of decoder layer of transformer decoder.
+
+ - weight_decay: The weight_decay for the optimizer.
+
+ - warm_step: The warm_step for Noam optimizer.
+ """
+ params = AttributeDict(
+ {
+ "best_train_loss": float("inf"),
+ "best_valid_loss": float("inf"),
+ "best_train_epoch": -1,
+ "best_valid_epoch": -1,
+ "batch_idx_train": 0,
+ "log_interval": 50,
+ "reset_interval": 200,
+ "valid_interval": 3000, # For the 100h subset, use 800
+ # parameters for conformer
+ "feature_dim": 80,
+ "encoder_out_dim": 512,
+ "subsampling_factor": 4,
+ "attention_dim": 512,
+ "nhead": 8,
+ "dim_feedforward": 2048,
+ "num_encoder_layers": 12,
+ "vgg_frontend": False,
+ "use_feat_batchnorm": True,
+ # parameters for Noam
+ "weight_decay": 1e-6,
+ "warm_step": 80000, # For the 100h subset, use 8k
+ "env_info": get_env_info(),
+ }
+ )
+
+ return params
+
+
+def get_encoder_model(params: AttributeDict):
+ # TODO: We can add an option to switch between Conformer and Transformer
+ encoder = Conformer(
+ num_features=params.feature_dim,
+ output_dim=params.encoder_out_dim,
+ subsampling_factor=params.subsampling_factor,
+ d_model=params.attention_dim,
+ nhead=params.nhead,
+ dim_feedforward=params.dim_feedforward,
+ num_encoder_layers=params.num_encoder_layers,
+ vgg_frontend=params.vgg_frontend,
+ use_feat_batchnorm=params.use_feat_batchnorm,
+ )
+ return encoder
+
+
+def get_decoder_model(params: AttributeDict):
+ decoder = Decoder(
+ vocab_size=params.vocab_size,
+ embedding_dim=params.encoder_out_dim,
+ blank_id=params.blank_id,
+ )
+ return decoder
+
+
+def get_joiner_model(params: AttributeDict):
+ joiner = Joiner(
+ input_dim=params.encoder_out_dim,
+ output_dim=params.vocab_size,
+ )
+ return joiner
+
+
+def get_transducer_model(params: AttributeDict):
+ encoder = get_encoder_model(params)
+ decoder = get_decoder_model(params)
+ joiner = get_joiner_model(params)
+
+ model = Transducer(
+ encoder=encoder,
+ decoder=decoder,
+ joiner=joiner,
+ )
+ return model
+
+
+def load_checkpoint_if_available(
+ params: AttributeDict,
+ model: nn.Module,
+ optimizer: Optional[torch.optim.Optimizer] = None,
+ scheduler: Optional[torch.optim.lr_scheduler._LRScheduler] = None,
+) -> None:
+ """Load checkpoint from file.
+
+ If params.start_epoch is positive, it will load the checkpoint from
+ `params.start_epoch - 1`. Otherwise, this function does nothing.
+
+ Apart from loading state dict for `model`, `optimizer` and `scheduler`,
+ it also updates `best_train_epoch`, `best_train_loss`, `best_valid_epoch`,
+ and `best_valid_loss` in `params`.
+
+ Args:
+ params:
+ The return value of :func:`get_params`.
+ model:
+ The training model.
+ optimizer:
+ The optimizer that we are using.
+ scheduler:
+ The learning rate scheduler we are using.
+ Returns:
+ Return None.
+ """
+ if params.start_epoch <= 0:
+ return
+
+ filename = params.exp_dir / f"epoch-{params.start_epoch-1}.pt"
+ saved_params = load_checkpoint(
+ filename,
+ model=model,
+ optimizer=optimizer,
+ scheduler=scheduler,
+ )
+
+ keys = [
+ "best_train_epoch",
+ "best_valid_epoch",
+ "batch_idx_train",
+ "best_train_loss",
+ "best_valid_loss",
+ ]
+ for k in keys:
+ params[k] = saved_params[k]
+
+ return saved_params
+
+
+def save_checkpoint(
+ params: AttributeDict,
+ model: nn.Module,
+ optimizer: Optional[torch.optim.Optimizer] = None,
+ scheduler: Optional[torch.optim.lr_scheduler._LRScheduler] = None,
+ rank: int = 0,
+) -> None:
+ """Save model, optimizer, scheduler and training stats to file.
+
+ Args:
+ params:
+ It is returned by :func:`get_params`.
+ model:
+ The training model.
+ """
+ if rank != 0:
+ return
+ filename = params.exp_dir / f"epoch-{params.cur_epoch}.pt"
+ save_checkpoint_impl(
+ filename=filename,
+ model=model,
+ params=params,
+ optimizer=optimizer,
+ scheduler=scheduler,
+ rank=rank,
+ )
+
+ if params.best_train_epoch == params.cur_epoch:
+ best_train_filename = params.exp_dir / "best-train-loss.pt"
+ copyfile(src=filename, dst=best_train_filename)
+
+ if params.best_valid_epoch == params.cur_epoch:
+ best_valid_filename = params.exp_dir / "best-valid-loss.pt"
+ copyfile(src=filename, dst=best_valid_filename)
+
+
+def compute_loss(
+ params: AttributeDict,
+ model: nn.Module,
+ sp: spm.SentencePieceProcessor,
+ batch: dict,
+ is_training: bool,
+) -> Tuple[Tensor, MetricsTracker]:
+ """
+ Compute CTC loss given the model and its inputs.
+
+ Args:
+ params:
+ Parameters for training. See :func:`get_params`.
+ model:
+ The model for training. It is an instance of Conformer in our case.
+ batch:
+ A batch of data. See `lhotse.dataset.K2SpeechRecognitionDataset()`
+ for the content in it.
+ is_training:
+ True for training. False for validation. When it is True, this
+ function enables autograd during computation; when it is False, it
+ disables autograd.
+ """
+ device = model.device
+ feature = batch["inputs"]
+ # at entry, feature is (N, T, C)
+ assert feature.ndim == 3
+ feature = feature.to(device)
+
+ supervisions = batch["supervisions"]
+ feature_lens = supervisions["num_frames"].to(device)
+
+ texts = batch["supervisions"]["text"]
+ y = sp.encode(texts, out_type=int)
+ y = k2.RaggedTensor(y).to(device)
+
+ with torch.set_grad_enabled(is_training):
+ loss = model(x=feature, x_lens=feature_lens, y=y)
+
+ assert loss.requires_grad == is_training
+
+ info = MetricsTracker()
+ info["frames"] = (feature_lens // params.subsampling_factor).sum().item()
+
+ # Note: We use reduction=sum while computing the loss.
+ info["loss"] = loss.detach().cpu().item()
+
+ return loss, info
+
+
+def compute_validation_loss(
+ params: AttributeDict,
+ model: nn.Module,
+ sp: spm.SentencePieceProcessor,
+ valid_dl: torch.utils.data.DataLoader,
+ world_size: int = 1,
+) -> MetricsTracker:
+ """Run the validation process."""
+ model.eval()
+
+ tot_loss = MetricsTracker()
+
+ for batch_idx, batch in enumerate(valid_dl):
+ loss, loss_info = compute_loss(
+ params=params,
+ model=model,
+ sp=sp,
+ batch=batch,
+ is_training=False,
+ )
+ assert loss.requires_grad is False
+ tot_loss = tot_loss + loss_info
+
+ if world_size > 1:
+ tot_loss.reduce(loss.device)
+
+ loss_value = tot_loss["loss"] / tot_loss["frames"]
+ if loss_value < params.best_valid_loss:
+ params.best_valid_epoch = params.cur_epoch
+ params.best_valid_loss = loss_value
+
+ return tot_loss
+
+
+def train_one_epoch(
+ params: AttributeDict,
+ model: nn.Module,
+ optimizer: torch.optim.Optimizer,
+ sp: spm.SentencePieceProcessor,
+ train_dl: torch.utils.data.DataLoader,
+ valid_dl: torch.utils.data.DataLoader,
+ tb_writer: Optional[SummaryWriter] = None,
+ world_size: int = 1,
+) -> None:
+ """Train the model for one epoch.
+
+ The training loss from the mean of all frames is saved in
+ `params.train_loss`. It runs the validation process every
+ `params.valid_interval` batches.
+
+ Args:
+ params:
+ It is returned by :func:`get_params`.
+ model:
+ The model for training.
+ optimizer:
+ The optimizer we are using.
+ train_dl:
+ Dataloader for the training dataset.
+ valid_dl:
+ Dataloader for the validation dataset.
+ tb_writer:
+ Writer to write log messages to tensorboard.
+ world_size:
+ Number of nodes in DDP training. If it is 1, DDP is disabled.
+ """
+ model.train()
+
+ tot_loss = MetricsTracker()
+
+ for batch_idx, batch in enumerate(train_dl):
+ params.batch_idx_train += 1
+ batch_size = len(batch["supervisions"]["text"])
+
+ loss, loss_info = compute_loss(
+ params=params,
+ model=model,
+ sp=sp,
+ batch=batch,
+ is_training=True,
+ )
+ # summary stats
+ tot_loss = (tot_loss * (1 - 1 / params.reset_interval)) + loss_info
+
+ # NOTE: We use reduction==sum and loss is computed over utterances
+ # in the batch and there is no normalization to it so far.
+
+ optimizer.zero_grad()
+ loss.backward()
+ clip_grad_norm_(model.parameters(), 5.0, 2.0)
+ optimizer.step()
+
+ if batch_idx % params.log_interval == 0:
+ logging.info(
+ f"Epoch {params.cur_epoch}, "
+ f"batch {batch_idx}, loss[{loss_info}], "
+ f"tot_loss[{tot_loss}], batch size: {batch_size}"
+ )
+
+ if batch_idx % params.log_interval == 0:
+
+ if tb_writer is not None:
+ loss_info.write_summary(
+ tb_writer, "train/current_", params.batch_idx_train
+ )
+ tot_loss.write_summary(
+ tb_writer, "train/tot_", params.batch_idx_train
+ )
+
+ if batch_idx > 0 and batch_idx % params.valid_interval == 0:
+ logging.info("Computing validation loss")
+ valid_info = compute_validation_loss(
+ params=params,
+ model=model,
+ sp=sp,
+ valid_dl=valid_dl,
+ world_size=world_size,
+ )
+ model.train()
+ logging.info(f"Epoch {params.cur_epoch}, validation: {valid_info}")
+ if tb_writer is not None:
+ valid_info.write_summary(
+ tb_writer, "train/valid_", params.batch_idx_train
+ )
+
+ loss_value = tot_loss["loss"] / tot_loss["frames"]
+ params.train_loss = loss_value
+ if params.train_loss < params.best_train_loss:
+ params.best_train_epoch = params.cur_epoch
+ params.best_train_loss = params.train_loss
+
+
+def run(rank, world_size, args):
+ """
+ Args:
+ rank:
+ It is a value between 0 and `world_size-1`, which is
+ passed automatically by `mp.spawn()` in :func:`main`.
+ The node with rank 0 is responsible for saving checkpoint.
+ world_size:
+ Number of GPUs for DDP training.
+ args:
+ The return value of get_parser().parse_args()
+ """
+ params = get_params()
+ params.update(vars(args))
+ if params.full_libri is False:
+ params.valid_interval = 800
+ params.warm_step = 8000
+
+ fix_random_seed(42)
+ if world_size > 1:
+ setup_dist(rank, world_size, params.master_port)
+
+ setup_logger(f"{params.exp_dir}/log/log-train")
+ logging.info("Training started")
+
+ if args.tensorboard and rank == 0:
+ tb_writer = SummaryWriter(log_dir=f"{params.exp_dir}/tensorboard")
+ else:
+ tb_writer = None
+
+ device = torch.device("cpu")
+ if torch.cuda.is_available():
+ device = torch.device("cuda", rank)
+ logging.info(f"Device: {device}")
+
+ sp = spm.SentencePieceProcessor()
+ sp.load(params.bpe_model)
+
+ # and are defined in local/train_bpe_model.py
+ params.blank_id = sp.piece_to_id("")
+ params.vocab_size = sp.get_piece_size()
+
+ logging.info(params)
+
+ logging.info("About to create model")
+ model = get_transducer_model(params)
+
+ num_param = sum([p.numel() for p in model.parameters()])
+ logging.info(f"Number of model parameters: {num_param}")
+
+ checkpoints = load_checkpoint_if_available(params=params, model=model)
+
+ model.to(device)
+ if world_size > 1:
+ logging.info("Using DDP")
+ model = DDP(model, device_ids=[rank])
+ model.device = device
+
+ optimizer = Noam(
+ model.parameters(),
+ model_size=params.attention_dim,
+ factor=params.lr_factor,
+ warm_step=params.warm_step,
+ weight_decay=params.weight_decay,
+ )
+
+ if checkpoints and "optimizer" in checkpoints:
+ logging.info("Loading optimizer state dict")
+ optimizer.load_state_dict(checkpoints["optimizer"])
+
+ librispeech = LibriSpeechAsrDataModule(args)
+
+ train_cuts = librispeech.train_clean_100_cuts()
+ if params.full_libri:
+ train_cuts += librispeech.train_clean_360_cuts()
+ train_cuts += librispeech.train_other_500_cuts()
+
+ def remove_short_and_long_utt(c: Cut):
+ # Keep only utterances with duration between 1 second and 20 seconds
+ return 1.0 <= c.duration <= 20.0
+
+ num_in_total = len(train_cuts)
+
+ train_cuts = train_cuts.filter(remove_short_and_long_utt)
+
+ num_left = len(train_cuts)
+ num_removed = num_in_total - num_left
+ removed_percent = num_removed / num_in_total * 100
+
+ logging.info(f"Before removing short and long utterances: {num_in_total}")
+ logging.info(f"After removing short and long utterances: {num_left}")
+ logging.info(f"Removed {num_removed} utterances ({removed_percent:.5f}%)")
+
+ train_dl = librispeech.train_dataloaders(train_cuts)
+
+ valid_cuts = librispeech.dev_clean_cuts()
+ valid_cuts += librispeech.dev_other_cuts()
+ valid_dl = librispeech.valid_dataloaders(valid_cuts)
+
+ scan_pessimistic_batches_for_oom(
+ model=model,
+ train_dl=train_dl,
+ optimizer=optimizer,
+ sp=sp,
+ params=params,
+ )
+
+ for epoch in range(params.start_epoch, params.num_epochs):
+ train_dl.sampler.set_epoch(epoch)
+
+ cur_lr = optimizer._rate
+ if tb_writer is not None:
+ tb_writer.add_scalar(
+ "train/learning_rate", cur_lr, params.batch_idx_train
+ )
+ tb_writer.add_scalar("train/epoch", epoch, params.batch_idx_train)
+
+ if rank == 0:
+ logging.info("epoch {}, learning rate {}".format(epoch, cur_lr))
+
+ params.cur_epoch = epoch
+
+ train_one_epoch(
+ params=params,
+ model=model,
+ optimizer=optimizer,
+ sp=sp,
+ train_dl=train_dl,
+ valid_dl=valid_dl,
+ tb_writer=tb_writer,
+ world_size=world_size,
+ )
+
+ save_checkpoint(
+ params=params,
+ model=model,
+ optimizer=optimizer,
+ rank=rank,
+ )
+
+ logging.info("Done!")
+
+ if world_size > 1:
+ torch.distributed.barrier()
+ cleanup_dist()
+
+
+def scan_pessimistic_batches_for_oom(
+ model: nn.Module,
+ train_dl: torch.utils.data.DataLoader,
+ optimizer: torch.optim.Optimizer,
+ sp: spm.SentencePieceProcessor,
+ params: AttributeDict,
+):
+ from lhotse.dataset import find_pessimistic_batches
+
+ logging.info(
+ "Sanity check -- see if any of the batches in epoch 0 would cause OOM."
+ )
+ batches, crit_values = find_pessimistic_batches(train_dl.sampler)
+ for criterion, cuts in batches.items():
+ batch = train_dl.dataset[cuts]
+ try:
+ optimizer.zero_grad()
+ loss, _ = compute_loss(
+ params=params,
+ model=model,
+ sp=sp,
+ batch=batch,
+ is_training=True,
+ )
+ loss.backward()
+ clip_grad_norm_(model.parameters(), 5.0, 2.0)
+ optimizer.step()
+ except RuntimeError as e:
+ if "CUDA out of memory" in str(e):
+ logging.error(
+ "Your GPU ran out of memory with the current "
+ "max_duration setting. We recommend decreasing "
+ "max_duration and trying again.\n"
+ f"Failing criterion: {criterion} "
+ f"(={crit_values[criterion]}) ..."
+ )
+ raise
+
+
+def main():
+ parser = get_parser()
+ LibriSpeechAsrDataModule.add_arguments(parser)
+ args = parser.parse_args()
+ args.exp_dir = Path(args.exp_dir)
+
+ world_size = args.world_size
+ assert world_size >= 1
+ if world_size > 1:
+ mp.spawn(run, args=(world_size, args), nprocs=world_size, join=True)
+ else:
+ run(rank=0, world_size=1, args=args)
+
+
+torch.set_num_threads(1)
+torch.set_num_interop_threads(1)
+
+if __name__ == "__main__":
+ main()
diff --git a/egs/librispeech/ASR/transducer_stateless/transformer.py b/egs/librispeech/ASR/transducer_stateless/transformer.py
new file mode 100644
index 000000000..e38e9e12c
--- /dev/null
+++ b/egs/librispeech/ASR/transducer_stateless/transformer.py
@@ -0,0 +1,429 @@
+# 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 Optional, Tuple
+
+import torch
+import torch.nn as nn
+from transducer.encoder_interface import EncoderInterface
+from transducer.subsampling import Conv2dSubsampling, VggSubsampling
+
+from icefall.utils import make_pad_mask
+
+
+class Transformer(EncoderInterface):
+ def __init__(
+ self,
+ num_features: int,
+ output_dim: int,
+ subsampling_factor: int = 4,
+ d_model: int = 256,
+ nhead: int = 4,
+ dim_feedforward: int = 2048,
+ num_encoder_layers: int = 12,
+ dropout: float = 0.1,
+ normalize_before: bool = True,
+ vgg_frontend: bool = False,
+ use_feat_batchnorm: bool = False,
+ ) -> None:
+ """
+ Args:
+ num_features:
+ The input dimension of the model.
+ output_dim:
+ 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.
+ num_encoder_layers:
+ Number of encoder layers.
+ dropout:
+ Dropout in encoder.
+ 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.
+ """
+ super().__init__()
+ self.use_feat_batchnorm = use_feat_batchnorm
+ if use_feat_batchnorm:
+ self.feat_batchnorm = nn.BatchNorm1d(num_features)
+
+ self.num_features = num_features
+ self.output_dim = output_dim
+ 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_features)
+ # 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_features -> 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, output_dim)
+ )
+
+ def forward(
+ self, x: torch.Tensor, x_lens: torch.Tensor
+ ) -> Tuple[torch.Tensor, torch.Tensor]:
+ """
+ Args:
+ x:
+ The input tensor. Its shape is (batch_size, seq_len, feature_dim).
+ x_lens:
+ A tensor of shape (batch_size,) containing the number of frames in
+ `x` before padding.
+ Returns:
+ Return a tuple containing 2 tensors:
+ - logits, its shape is (batch_size, output_seq_len, output_dim)
+ - logit_lens, a tensor of shape (batch_size,) containing the number
+ of frames in `logits` before padding.
+ """
+ if 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)
+
+ x = self.encoder_embed(x)
+ x = self.encoder_pos(x)
+ x = x.permute(1, 0, 2) # (N, T, C) -> (T, N, C)
+
+ # Caution: We assume the subsampling factor is 4!
+ lengths = ((x_lens - 1) // 2 - 1) // 2
+ assert x.size(0) == lengths.max().item()
+
+ mask = make_pad_mask(lengths)
+ x = self.encoder(x, src_key_padding_mask=mask) # (T, N, C)
+
+ logits = self.encoder_output_layer(x)
+ logits = logits.permute(1, 0, 2) # (T, N, C) ->(N, T, C)
+
+ return logits, lengths
+
+
+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
+
+
+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)
diff --git a/egs/yesno/ASR/transducer/beam_search.py b/egs/yesno/ASR/transducer/beam_search.py
index ae0f39478..b98090636 100644
--- a/egs/yesno/ASR/transducer/beam_search.py
+++ b/egs/yesno/ASR/transducer/beam_search.py
@@ -20,7 +20,7 @@ import torch
from transducer.model import Transducer
-def greedy_search(model: Transducer, encoder_out: torch.Tensor) -> List[int]:
+def greedy_search(model: Transducer, encoder_out: torch.Tensor) -> List[str]:
"""
Args:
model:
@@ -42,7 +42,7 @@ def greedy_search(model: Transducer, encoder_out: torch.Tensor) -> List[int]:
T = encoder_out.size(1)
t = 0
hyp = []
- max_u = 1000 # terminte after this number of steps
+ max_u = 1000 # terminate after this number of steps
u = 0
while t < T and u < max_u: