diff --git a/README.md b/README.md
index c501e0c3..9a049df8 100644
--- a/README.md
+++ b/README.md
@@ -335,4 +335,4 @@ PaddleSpeech is provided under the [Apache-2.0 License](./LICENSE).
 
 ## Acknowledgement
 
-PaddleSpeech depends on a lot of open source repos. See [references](docs/source/asr/reference.md) for more information.
+PaddleSpeech depends on a lot of open source repos. See [references](docs/source/reference.md) for more information.
diff --git a/audio/paddleaudio/features/core.py b/audio/paddleaudio/features/core.py
index f53f60f3..dd25724f 100644
--- a/audio/paddleaudio/features/core.py
+++ b/audio/paddleaudio/features/core.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from librosa(https://github.com/librosa/librosa)
 import warnings
 from typing import List
 from typing import Optional
diff --git a/docs/source/asr/reference.md b/docs/source/asr/reference.md
deleted file mode 100644
index d3676fff..00000000
--- a/docs/source/asr/reference.md
+++ /dev/null
@@ -1,8 +0,0 @@
-# Reference
-
-We refer these repos to build `model` and `engine`:
-
-* [delta](https://github.com/Delta-ML/delta.git)
-* [espnet](https://github.com/espnet/espnet.git)
-* [kaldi](https://github.com/kaldi-asr/kaldi.git)
-* [wenet](https://github.com/mobvoi/wenet)
diff --git a/docs/source/reference.md b/docs/source/reference.md
new file mode 100644
index 00000000..39c7afe5
--- /dev/null
+++ b/docs/source/reference.md
@@ -0,0 +1,37 @@
+# Reference
+
+We borrowed a lot of code from these repos to build `model` and `engine`, thank for these great work:
+
+* [espnet](https://github.com/espnet/espnet/blob/master/LICENSE)
+- Apache-2.0 License
+- python/shell `utils`
+- kaldi feat preprocessing
+- datapipeline and `transform`
+- a lot of tts model, like `fastspeech2` and GAN-based `vocoder`
+
+* [wenet](https://github.com/wenet-e2e/wenet/blob/main/LICENSE)
+- Apache-2.0 License
+- U2 model
+- Building TLG based Graph
+
+* [kaldi](https://github.com/kaldi-asr/kaldi/blob/master/COPYING)
+- Apache-2.0 License
+- shell/perl/python utils.
+- feature bins.
+- WFST based decoding for LM integration.
+
+* [delta](https://github.com/Delta-ML/delta/blob/master/LICENSE)
+- Apache-2.0 License
+- `engine` arch
+
+* [speechbrain](https://github.com/speechbrain/speechbrain/blob/develop/LICENSE)
+- Apache-2.0 License
+- ECAPA-TDNN SV model
+
+* [chainer](https://github.com/chainer/chainer/blob/master/LICENSE)
+- MIT License
+- Updater, Trainer and more utils.
+
+* [librosa](https://github.com/librosa/librosa/blob/main/LICENSE.md)
+- ISC License
+- Audio feature
diff --git a/paddlespeech/s2t/decoders/README.md b/paddlespeech/s2t/decoders/README.md
index ee7d53de..0b91ddd1 100644
--- a/paddlespeech/s2t/decoders/README.md
+++ b/paddlespeech/s2t/decoders/README.md
@@ -1,4 +1,5 @@
 # Decoders
+we borrow a lot of code from Espnet Apache 2.0  (http://www.apache.org/licenses/LICENSE-2.0)
 
 ## Reference
 ### CTC Prefix Beam Search
diff --git a/paddlespeech/s2t/decoders/beam_search/batch_beam_search.py b/paddlespeech/s2t/decoders/beam_search/batch_beam_search.py
index 3fc1c435..ed9790cd 100644
--- a/paddlespeech/s2t/decoders/beam_search/batch_beam_search.py
+++ b/paddlespeech/s2t/decoders/beam_search/batch_beam_search.py
@@ -11,6 +11,7 @@
 # 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.
+# Reference espnet Apache 2.0 (http://www.apache.org/licenses/LICENSE-2.0)
 
 
 class BatchBeamSearch():
diff --git a/paddlespeech/s2t/decoders/beam_search/beam_search.py b/paddlespeech/s2t/decoders/beam_search/beam_search.py
index 6c4f069d..f331cb1c 100644
--- a/paddlespeech/s2t/decoders/beam_search/beam_search.py
+++ b/paddlespeech/s2t/decoders/beam_search/beam_search.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from espnet(https://github.com/espnet/espnet)
 """Beam search module."""
 from itertools import chain
 from typing import Any
diff --git a/paddlespeech/s2t/decoders/recog.py b/paddlespeech/s2t/decoders/recog.py
index d0710f9c..d9324ca0 100644
--- a/paddlespeech/s2t/decoders/recog.py
+++ b/paddlespeech/s2t/decoders/recog.py
@@ -11,6 +11,7 @@
 # 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.
+# Reference espnet Apache 2.0 (http://www.apache.org/licenses/LICENSE-2.0)
 """V2 backend for `asr_recog.py` using py:class:`decoders.beam_search.BeamSearch`."""
 import jsonlines
 import paddle
diff --git a/paddlespeech/s2t/decoders/recog_bin.py b/paddlespeech/s2t/decoders/recog_bin.py
index e4d81f40..cd7a360a 100644
--- a/paddlespeech/s2t/decoders/recog_bin.py
+++ b/paddlespeech/s2t/decoders/recog_bin.py
@@ -11,6 +11,7 @@
 # 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.
+# Reference espnet Apache 2.0 (http://www.apache.org/licenses/LICENSE-2.0)
 """End-to-end speech recognition model decoding script."""
 import logging
 import os
diff --git a/paddlespeech/s2t/decoders/scorers/ctc.py b/paddlespeech/s2t/decoders/scorers/ctc.py
index 74a5f578..ace80bd3 100644
--- a/paddlespeech/s2t/decoders/scorers/ctc.py
+++ b/paddlespeech/s2t/decoders/scorers/ctc.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from espnet(https://github.com/espnet/espnet)
 """ScorerInterface implementation for CTC."""
 import numpy as np
 import paddle
diff --git a/paddlespeech/s2t/decoders/scorers/length_bonus.py b/paddlespeech/s2t/decoders/scorers/length_bonus.py
index 864e22d1..c5a76db8 100644
--- a/paddlespeech/s2t/decoders/scorers/length_bonus.py
+++ b/paddlespeech/s2t/decoders/scorers/length_bonus.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from espnet(https://github.com/espnet/espnet)
 """Length bonus module."""
 from typing import Any
 from typing import List
diff --git a/paddlespeech/s2t/decoders/scorers/ngram.py b/paddlespeech/s2t/decoders/scorers/ngram.py
index a34d8248..f2600828 100644
--- a/paddlespeech/s2t/decoders/scorers/ngram.py
+++ b/paddlespeech/s2t/decoders/scorers/ngram.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from espnet(https://github.com/espnet/espnet)
 """Ngram lm implement."""
 from abc import ABC
 
diff --git a/paddlespeech/s2t/decoders/scorers/scorer_interface.py b/paddlespeech/s2t/decoders/scorers/scorer_interface.py
index 366904a4..3272e6b7 100644
--- a/paddlespeech/s2t/decoders/scorers/scorer_interface.py
+++ b/paddlespeech/s2t/decoders/scorers/scorer_interface.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from espnet(https://github.com/espnet/espnet)
 """Scorer interface module."""
 import warnings
 from typing import Any
diff --git a/paddlespeech/s2t/decoders/utils.py b/paddlespeech/s2t/decoders/utils.py
index 7dff14c1..a609f1c6 100644
--- a/paddlespeech/s2t/decoders/utils.py
+++ b/paddlespeech/s2t/decoders/utils.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from espnet(https://github.com/espnet/espnet)
 import numpy as np
 
 from paddlespeech.s2t.utils.log import Log
diff --git a/paddlespeech/s2t/io/batchfy.py b/paddlespeech/s2t/io/batchfy.py
index 3517f059..f59fb24c 100644
--- a/paddlespeech/s2t/io/batchfy.py
+++ b/paddlespeech/s2t/io/batchfy.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from espnet(https://github.com/espnet/espnet)
 import itertools
 
 import numpy as np
diff --git a/paddlespeech/s2t/io/converter.py b/paddlespeech/s2t/io/converter.py
index 94634360..b217d2b1 100644
--- a/paddlespeech/s2t/io/converter.py
+++ b/paddlespeech/s2t/io/converter.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from espnet(https://github.com/espnet/espnet)
 import numpy as np
 
 from paddlespeech.s2t.io.utility import pad_list
diff --git a/paddlespeech/s2t/io/dataset.py b/paddlespeech/s2t/io/dataset.py
index 121410c8..7c96cb43 100644
--- a/paddlespeech/s2t/io/dataset.py
+++ b/paddlespeech/s2t/io/dataset.py
@@ -11,6 +11,8 @@
 # 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.
+# Modified from espnet(https://github.com/espnet/espnet)
+# Modified from wenet(https://github.com/wenet-e2e/wenet)
 from typing import Optional
 
 from paddle.io import Dataset
diff --git a/paddlespeech/s2t/io/reader.py b/paddlespeech/s2t/io/reader.py
index faf2f600..e810662d 100644
--- a/paddlespeech/s2t/io/reader.py
+++ b/paddlespeech/s2t/io/reader.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from espnet(https://github.com/espnet/espnet)
 from collections import OrderedDict
 
 import kaldiio
diff --git a/paddlespeech/s2t/models/asr_interface.py b/paddlespeech/s2t/models/asr_interface.py
index ece83e51..8c2db279 100644
--- a/paddlespeech/s2t/models/asr_interface.py
+++ b/paddlespeech/s2t/models/asr_interface.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from espnet(https://github.com/espnet/espnet)
 """ASR Interface module."""
 import argparse
 
diff --git a/paddlespeech/s2t/models/lm/transformer.py b/paddlespeech/s2t/models/lm/transformer.py
index 447f1dbc..85bd7c23 100644
--- a/paddlespeech/s2t/models/lm/transformer.py
+++ b/paddlespeech/s2t/models/lm/transformer.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from espnet(https://github.com/espnet/espnet)
 from typing import Any
 from typing import List
 from typing import Tuple
diff --git a/paddlespeech/s2t/models/lm_interface.py b/paddlespeech/s2t/models/lm_interface.py
index 7ae39b35..c8f3776a 100644
--- a/paddlespeech/s2t/models/lm_interface.py
+++ b/paddlespeech/s2t/models/lm_interface.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from espnet(https://github.com/espnet/espnet)
 """Language model interface."""
 import argparse
 
diff --git a/paddlespeech/s2t/models/st_interface.py b/paddlespeech/s2t/models/st_interface.py
index 331f1e82..4d368590 100644
--- a/paddlespeech/s2t/models/st_interface.py
+++ b/paddlespeech/s2t/models/st_interface.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from espnet(https://github.com/espnet/espnet)
 """ST Interface module."""
 from .asr_interface import ASRInterface
 from paddlespeech.s2t.utils.dynamic_import import dynamic_import
diff --git a/paddlespeech/s2t/modules/attention.py b/paddlespeech/s2t/modules/attention.py
index d5246777..80eaf975 100644
--- a/paddlespeech/s2t/modules/attention.py
+++ b/paddlespeech/s2t/modules/attention.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from wenet(https://github.com/wenet-e2e/wenet)
 """Multi-Head Attention layer definition."""
 import math
 from typing import Optional
diff --git a/paddlespeech/s2t/modules/cmvn.py b/paddlespeech/s2t/modules/cmvn.py
index 9aa938af..6e97f824 100644
--- a/paddlespeech/s2t/modules/cmvn.py
+++ b/paddlespeech/s2t/modules/cmvn.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from wenet(https://github.com/wenet-e2e/wenet)
 import paddle
 from paddle import nn
 
diff --git a/paddlespeech/s2t/modules/conformer_convolution.py b/paddlespeech/s2t/modules/conformer_convolution.py
index 39b1ee32..7601a5cc 100644
--- a/paddlespeech/s2t/modules/conformer_convolution.py
+++ b/paddlespeech/s2t/modules/conformer_convolution.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from wenet(https://github.com/wenet-e2e/wenet)
 """ConvolutionModule definition."""
 from typing import Optional
 from typing import Tuple
diff --git a/paddlespeech/s2t/modules/decoder.py b/paddlespeech/s2t/modules/decoder.py
index 7d545f5e..b0ab869a 100644
--- a/paddlespeech/s2t/modules/decoder.py
+++ b/paddlespeech/s2t/modules/decoder.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from wenet(https://github.com/wenet-e2e/wenet)
 """Decoder definition."""
 from typing import Any
 from typing import List
diff --git a/paddlespeech/s2t/modules/decoder_layer.py b/paddlespeech/s2t/modules/decoder_layer.py
index 816bc9f6..4d516068 100644
--- a/paddlespeech/s2t/modules/decoder_layer.py
+++ b/paddlespeech/s2t/modules/decoder_layer.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from wenet(https://github.com/wenet-e2e/wenet)
 """Decoder self-attention layer definition."""
 from typing import Optional
 from typing import Tuple
diff --git a/paddlespeech/s2t/modules/embedding.py b/paddlespeech/s2t/modules/embedding.py
index 938898c1..9207658f 100644
--- a/paddlespeech/s2t/modules/embedding.py
+++ b/paddlespeech/s2t/modules/embedding.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from wenet(https://github.com/wenet-e2e/wenet)
 """Positonal Encoding Module."""
 import math
 from typing import Tuple
diff --git a/paddlespeech/s2t/modules/encoder.py b/paddlespeech/s2t/modules/encoder.py
index 246536db..0cde5b9f 100644
--- a/paddlespeech/s2t/modules/encoder.py
+++ b/paddlespeech/s2t/modules/encoder.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from wenet(https://github.com/wenet-e2e/wenet)
 """Encoder definition."""
 from typing import List
 from typing import Optional
diff --git a/paddlespeech/s2t/modules/encoder_layer.py b/paddlespeech/s2t/modules/encoder_layer.py
index 0525a614..29d5a2d8 100644
--- a/paddlespeech/s2t/modules/encoder_layer.py
+++ b/paddlespeech/s2t/modules/encoder_layer.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from wenet(https://github.com/wenet-e2e/wenet)
 """Encoder self-attention layer definition."""
 from typing import Optional
 from typing import Tuple
diff --git a/paddlespeech/s2t/modules/loss.py b/paddlespeech/s2t/modules/loss.py
index 012ef242..5750f5a0 100644
--- a/paddlespeech/s2t/modules/loss.py
+++ b/paddlespeech/s2t/modules/loss.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from wenet(https://github.com/wenet-e2e/wenet)
 import inspect
 
 import paddle
diff --git a/paddlespeech/s2t/modules/mask.py b/paddlespeech/s2t/modules/mask.py
index 5c7886d4..6576cb92 100644
--- a/paddlespeech/s2t/modules/mask.py
+++ b/paddlespeech/s2t/modules/mask.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from wenet(https://github.com/wenet-e2e/wenet)
 import paddle
 
 from paddlespeech.s2t.utils.log import Log
diff --git a/paddlespeech/s2t/modules/positionwise_feed_forward.py b/paddlespeech/s2t/modules/positionwise_feed_forward.py
index ccea8e57..347264e9 100644
--- a/paddlespeech/s2t/modules/positionwise_feed_forward.py
+++ b/paddlespeech/s2t/modules/positionwise_feed_forward.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from wenet(https://github.com/wenet-e2e/wenet)
 """Positionwise feed forward layer definition."""
 import paddle
 from paddle import nn
diff --git a/paddlespeech/s2t/modules/subsampling.py b/paddlespeech/s2t/modules/subsampling.py
index 6b8c28c6..759bd540 100644
--- a/paddlespeech/s2t/modules/subsampling.py
+++ b/paddlespeech/s2t/modules/subsampling.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from wenet(https://github.com/wenet-e2e/wenet)
 """Subsampling layer definition."""
 from typing import Tuple
 
diff --git a/paddlespeech/s2t/training/extensions/evaluator.py b/paddlespeech/s2t/training/extensions/evaluator.py
index 9da0d731..b96a4818 100644
--- a/paddlespeech/s2t/training/extensions/evaluator.py
+++ b/paddlespeech/s2t/training/extensions/evaluator.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from chainer(https://github.com/chainer/chainer)
 from typing import Dict
 
 import paddle
diff --git a/paddlespeech/s2t/training/extensions/extension.py b/paddlespeech/s2t/training/extensions/extension.py
index 02f92495..7493213a 100644
--- a/paddlespeech/s2t/training/extensions/extension.py
+++ b/paddlespeech/s2t/training/extensions/extension.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from chainer(https://github.com/chainer/chainer)
 PRIORITY_WRITER = 300
 PRIORITY_EDITOR = 200
 PRIORITY_READER = 100
diff --git a/paddlespeech/s2t/training/extensions/plot.py b/paddlespeech/s2t/training/extensions/plot.py
index 6fbb4d4d..7782b95b 100644
--- a/paddlespeech/s2t/training/extensions/plot.py
+++ b/paddlespeech/s2t/training/extensions/plot.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from chainer(https://github.com/chainer/chainer)
 import copy
 import os
 
diff --git a/paddlespeech/s2t/training/extensions/snapshot.py b/paddlespeech/s2t/training/extensions/snapshot.py
index 753c7ec0..426bf72c 100644
--- a/paddlespeech/s2t/training/extensions/snapshot.py
+++ b/paddlespeech/s2t/training/extensions/snapshot.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from chainer(https://github.com/chainer/chainer)
 import os
 from datetime import datetime
 from pathlib import Path
diff --git a/paddlespeech/s2t/training/optimizer.py b/paddlespeech/s2t/training/optimizer.py
index 8ed30769..f7f70c57 100644
--- a/paddlespeech/s2t/training/optimizer.py
+++ b/paddlespeech/s2t/training/optimizer.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from espnet(https://github.com/espnet/espnet)
 from typing import Any
 from typing import Dict
 from typing import Text
diff --git a/paddlespeech/s2t/training/reporter.py b/paddlespeech/s2t/training/reporter.py
index 7afc33f3..4d8eb2a1 100644
--- a/paddlespeech/s2t/training/reporter.py
+++ b/paddlespeech/s2t/training/reporter.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from chainer(https://github.com/chainer/chainer)
 import contextlib
 import math
 from collections import defaultdict
diff --git a/paddlespeech/s2t/training/scheduler.py b/paddlespeech/s2t/training/scheduler.py
index f850f6f5..0222246e 100644
--- a/paddlespeech/s2t/training/scheduler.py
+++ b/paddlespeech/s2t/training/scheduler.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from espnet(https://github.com/espnet/espnet)
 from typing import Any
 from typing import Dict
 from typing import Text
diff --git a/paddlespeech/s2t/training/triggers/compare_value_trigger.py b/paddlespeech/s2t/training/triggers/compare_value_trigger.py
index efb928e2..5c2a2721 100644
--- a/paddlespeech/s2t/training/triggers/compare_value_trigger.py
+++ b/paddlespeech/s2t/training/triggers/compare_value_trigger.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from chainer(https://github.com/chainer/chainer)
 from ..reporter import DictSummary
 from .utils import get_trigger
 
diff --git a/paddlespeech/s2t/training/triggers/interval_trigger.py b/paddlespeech/s2t/training/triggers/interval_trigger.py
index 1e04afad..14201d29 100644
--- a/paddlespeech/s2t/training/triggers/interval_trigger.py
+++ b/paddlespeech/s2t/training/triggers/interval_trigger.py
@@ -11,6 +11,7 @@
 # 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.
+# Reference chainer MIT (https://opensource.org/licenses/MIT)
 
 
 class IntervalTrigger():
diff --git a/paddlespeech/s2t/training/triggers/limit_trigger.py b/paddlespeech/s2t/training/triggers/limit_trigger.py
index ecd527ac..cd96040e 100644
--- a/paddlespeech/s2t/training/triggers/limit_trigger.py
+++ b/paddlespeech/s2t/training/triggers/limit_trigger.py
@@ -11,6 +11,7 @@
 # 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.
+# Reference chainer MIT (https://opensource.org/licenses/MIT)
 
 
 class LimitTrigger():
diff --git a/paddlespeech/s2t/training/triggers/time_trigger.py b/paddlespeech/s2t/training/triggers/time_trigger.py
index e31179a9..53c398d1 100644
--- a/paddlespeech/s2t/training/triggers/time_trigger.py
+++ b/paddlespeech/s2t/training/triggers/time_trigger.py
@@ -11,6 +11,7 @@
 # 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.
+# Reference chainer MIT (https://opensource.org/licenses/MIT)
 
 
 class TimeTrigger():
diff --git a/paddlespeech/s2t/training/updaters/standard_updater.py b/paddlespeech/s2t/training/updaters/standard_updater.py
index 83180a38..a320a80d 100644
--- a/paddlespeech/s2t/training/updaters/standard_updater.py
+++ b/paddlespeech/s2t/training/updaters/standard_updater.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from chainer(https://github.com/chainer/chainer)
 from typing import Dict
 from typing import Optional
 
diff --git a/paddlespeech/s2t/training/updaters/trainer.py b/paddlespeech/s2t/training/updaters/trainer.py
index dcf844e3..a0698c60 100644
--- a/paddlespeech/s2t/training/updaters/trainer.py
+++ b/paddlespeech/s2t/training/updaters/trainer.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from chainer(https://github.com/chainer/chainer)
 import sys
 import traceback
 from collections import OrderedDict
diff --git a/paddlespeech/s2t/training/updaters/updater.py b/paddlespeech/s2t/training/updaters/updater.py
index ff8d925f..6875deb3 100644
--- a/paddlespeech/s2t/training/updaters/updater.py
+++ b/paddlespeech/s2t/training/updaters/updater.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from chainer(https://github.com/chainer/chainer)
 from dataclasses import dataclass
 
 import paddle
diff --git a/paddlespeech/s2t/transform/add_deltas.py b/paddlespeech/s2t/transform/add_deltas.py
index 4cab0084..1387fe9d 100644
--- a/paddlespeech/s2t/transform/add_deltas.py
+++ b/paddlespeech/s2t/transform/add_deltas.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from espnet(https://github.com/espnet/espnet)
 import numpy as np
 
 
diff --git a/paddlespeech/s2t/transform/channel_selector.py b/paddlespeech/s2t/transform/channel_selector.py
index d985b482..b078dcf8 100644
--- a/paddlespeech/s2t/transform/channel_selector.py
+++ b/paddlespeech/s2t/transform/channel_selector.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from espnet(https://github.com/espnet/espnet)
 import numpy
 
 
diff --git a/paddlespeech/s2t/transform/cmvn.py b/paddlespeech/s2t/transform/cmvn.py
index 5d318590..4d2d2324 100644
--- a/paddlespeech/s2t/transform/cmvn.py
+++ b/paddlespeech/s2t/transform/cmvn.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from espnet(https://github.com/espnet/espnet)
 import io
 
 import h5py
diff --git a/paddlespeech/s2t/transform/functional.py b/paddlespeech/s2t/transform/functional.py
index e23d55f9..ccb50081 100644
--- a/paddlespeech/s2t/transform/functional.py
+++ b/paddlespeech/s2t/transform/functional.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from espnet(https://github.com/espnet/espnet)
 import inspect
 
 from paddlespeech.s2t.transform.transform_interface import TransformInterface
diff --git a/paddlespeech/s2t/transform/perturb.py b/paddlespeech/s2t/transform/perturb.py
index f7e8bb76..153d494b 100644
--- a/paddlespeech/s2t/transform/perturb.py
+++ b/paddlespeech/s2t/transform/perturb.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from espnet(https://github.com/espnet/espnet)
 import librosa
 import numpy
 import scipy
diff --git a/paddlespeech/s2t/transform/spec_augment.py b/paddlespeech/s2t/transform/spec_augment.py
index 01ead8ad..83e4e2e7 100644
--- a/paddlespeech/s2t/transform/spec_augment.py
+++ b/paddlespeech/s2t/transform/spec_augment.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from espnet(https://github.com/espnet/espnet)
 """Spec Augment module for preprocessing i.e., data augmentation"""
 import random
 
diff --git a/paddlespeech/s2t/transform/spectrogram.py b/paddlespeech/s2t/transform/spectrogram.py
index e63bd680..df3130da 100644
--- a/paddlespeech/s2t/transform/spectrogram.py
+++ b/paddlespeech/s2t/transform/spectrogram.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from espnet(https://github.com/espnet/espnet)
 import librosa
 import numpy as np
 
diff --git a/paddlespeech/s2t/transform/transform_interface.py b/paddlespeech/s2t/transform/transform_interface.py
index 7ab29554..8bc62420 100644
--- a/paddlespeech/s2t/transform/transform_interface.py
+++ b/paddlespeech/s2t/transform/transform_interface.py
@@ -11,7 +11,9 @@
 # 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.
-# TODO(karita): add this to all the transform impl.
+# Modified from espnet(https://github.com/espnet/espnet)
+
+
 class TransformInterface:
     """Transform Interface"""
 
diff --git a/paddlespeech/s2t/transform/transformation.py b/paddlespeech/s2t/transform/transformation.py
index d9bb7c16..1aee4b36 100644
--- a/paddlespeech/s2t/transform/transformation.py
+++ b/paddlespeech/s2t/transform/transformation.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from espnet(https://github.com/espnet/espnet)
 """Transformation module."""
 import copy
 import io
@@ -23,8 +24,6 @@ import yaml
 
 from paddlespeech.s2t.utils.dynamic_import import dynamic_import
 
-# TODO(karita): inherit TransformInterface
-# TODO(karita): register cmd arguments in asr_train.py
 import_alias = dict(
     identity="paddlespeech.s2t.transform.transform_interface:Identity",
     time_warp="paddlespeech.s2t.transform.spec_augment:TimeWarp",
diff --git a/paddlespeech/s2t/transform/wpe.py b/paddlespeech/s2t/transform/wpe.py
index d82005f6..777379d0 100644
--- a/paddlespeech/s2t/transform/wpe.py
+++ b/paddlespeech/s2t/transform/wpe.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from espnet(https://github.com/espnet/espnet)
 from nara_wpe.wpe import wpe
 
 
diff --git a/paddlespeech/s2t/utils/asr_utils.py b/paddlespeech/s2t/utils/asr_utils.py
index 6f86e56f..9184fd6a 100644
--- a/paddlespeech/s2t/utils/asr_utils.py
+++ b/paddlespeech/s2t/utils/asr_utils.py
@@ -11,6 +11,7 @@
 # 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.
+# Reference espnet Apache 2.0 (http://www.apache.org/licenses/LICENSE-2.0)
 import json
 
 import numpy as np
@@ -18,7 +19,6 @@ import numpy as np
 __all__ = ["label_smoothing_dist"]
 
 
-# TODO(takaaki-hori): add different smoothing methods
 def label_smoothing_dist(odim, lsm_type, transcript=None, blank=0):
     """Obtain label distribution for loss smoothing.
 
diff --git a/paddlespeech/s2t/utils/check_kwargs.py b/paddlespeech/s2t/utils/check_kwargs.py
index 1ee7329b..0aa839ac 100644
--- a/paddlespeech/s2t/utils/check_kwargs.py
+++ b/paddlespeech/s2t/utils/check_kwargs.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from espnet(https://github.com/espnet/espnet)
 import inspect
 
 
diff --git a/paddlespeech/s2t/utils/cli_readers.py b/paddlespeech/s2t/utils/cli_readers.py
index 010adb7a..735d590d 100644
--- a/paddlespeech/s2t/utils/cli_readers.py
+++ b/paddlespeech/s2t/utils/cli_readers.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from espnet(https://github.com/espnet/espnet)
 import io
 import logging
 import sys
diff --git a/paddlespeech/s2t/utils/cli_utils.py b/paddlespeech/s2t/utils/cli_utils.py
index f8e1d60b..4aee3f43 100644
--- a/paddlespeech/s2t/utils/cli_utils.py
+++ b/paddlespeech/s2t/utils/cli_utils.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from espnet(https://github.com/espnet/espnet)
 import sys
 from collections.abc import Sequence
 from distutils.util import strtobool as dist_strtobool
diff --git a/paddlespeech/s2t/utils/cli_writers.py b/paddlespeech/s2t/utils/cli_writers.py
index 5866a82e..d3a4c2b8 100644
--- a/paddlespeech/s2t/utils/cli_writers.py
+++ b/paddlespeech/s2t/utils/cli_writers.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from espnet(https://github.com/espnet/espnet)
 from pathlib import Path
 from typing import Dict
 
diff --git a/paddlespeech/s2t/utils/ctc_utils.py b/paddlespeech/s2t/utils/ctc_utils.py
index ff23350a..e005e5d2 100644
--- a/paddlespeech/s2t/utils/ctc_utils.py
+++ b/paddlespeech/s2t/utils/ctc_utils.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from wenet(https://github.com/wenet-e2e/wenet)
 from typing import List
 
 import numpy as np
@@ -138,16 +139,6 @@ def forced_align(ctc_probs: paddle.Tensor, y: paddle.Tensor,
     return output_alignment
 
 
-# ctc_align(
-# self.model,
-# self.align_loader,
-# self.config.decoding.batch_size,
-# self.align_loader.collate_fn.stride_ms,
-# self.align_loader.collate_fn.vocab_list,
-# self.args.result_file,
-# )
-
-
 def ctc_align(model, dataloader, batch_size, stride_ms, token_dict,
               result_file):
     """ctc alignment.
diff --git a/paddlespeech/s2t/utils/dynamic_import.py b/paddlespeech/s2t/utils/dynamic_import.py
index ddf17afe..50bd73a6 100644
--- a/paddlespeech/s2t/utils/dynamic_import.py
+++ b/paddlespeech/s2t/utils/dynamic_import.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from espnet(https://github.com/espnet/espnet)
 import importlib
 import inspect
 from typing import Any
diff --git a/paddlespeech/t2s/data/batch.py b/paddlespeech/t2s/data/batch.py
index 5e7ac399..9d83bbe0 100644
--- a/paddlespeech/t2s/data/batch.py
+++ b/paddlespeech/t2s/data/batch.py
@@ -52,9 +52,8 @@ def batch_text_id(minibatch, pad_id=0, dtype=np.int64):
     """
     peek_example = minibatch[0]
     assert len(peek_example.shape) == 1, "text example is an 1D tensor"
-
-    lengths = [example.shape[0] for example in
-               minibatch]  # assume (channel, n_samples) or (n_samples, )
+    # assume (channel, n_samples) or (n_samples, )
+    lengths = [example.shape[0] for example in minibatch]
     max_len = np.max(lengths)
 
     batch = []
diff --git a/paddlespeech/t2s/data/get_feats.py b/paddlespeech/t2s/data/get_feats.py
index d7ab7640..b4bea0bd 100644
--- a/paddlespeech/t2s/data/get_feats.py
+++ b/paddlespeech/t2s/data/get_feats.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from espnet(https://github.com/espnet/espnet)
 import librosa
 import numpy as np
 import pyworld
diff --git a/paddlespeech/t2s/models/fastspeech2/fastspeech2.py b/paddlespeech/t2s/models/fastspeech2/fastspeech2.py
index 754fef2a..5942533a 100644
--- a/paddlespeech/t2s/models/fastspeech2/fastspeech2.py
+++ b/paddlespeech/t2s/models/fastspeech2/fastspeech2.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from espnet(https://github.com/espnet/espnet)
 """Fastspeech2 related modules for paddle"""
 from typing import Dict
 from typing import Sequence
diff --git a/paddlespeech/t2s/models/melgan/melgan.py b/paddlespeech/t2s/models/melgan/melgan.py
index 94d6e631..80bb1c1b 100644
--- a/paddlespeech/t2s/models/melgan/melgan.py
+++ b/paddlespeech/t2s/models/melgan/melgan.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from espnet(https://github.com/espnet/espnet)
 """MelGAN Modules."""
 from typing import Any
 from typing import Dict
diff --git a/paddlespeech/t2s/models/parallel_wavegan/parallel_wavegan.py b/paddlespeech/t2s/models/parallel_wavegan/parallel_wavegan.py
index fe4ec355..9b0ba474 100644
--- a/paddlespeech/t2s/models/parallel_wavegan/parallel_wavegan.py
+++ b/paddlespeech/t2s/models/parallel_wavegan/parallel_wavegan.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from espnet(https://github.com/espnet/espnet)
 import math
 from typing import Any
 from typing import Dict
diff --git a/paddlespeech/t2s/models/transformer_tts/transformer_tts.py b/paddlespeech/t2s/models/transformer_tts/transformer_tts.py
index f8feb553..97233c76 100644
--- a/paddlespeech/t2s/models/transformer_tts/transformer_tts.py
+++ b/paddlespeech/t2s/models/transformer_tts/transformer_tts.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from espnet(https://github.com/espnet/espnet)
 """Fastspeech2 related modules for paddle"""
 from typing import Dict
 from typing import Sequence
diff --git a/paddlespeech/t2s/modules/adversarial_loss.py b/paddlespeech/t2s/modules/adversarial_loss.py
index 02e8c807..d2c8f7a9 100644
--- a/paddlespeech/t2s/modules/adversarial_loss.py
+++ b/paddlespeech/t2s/modules/adversarial_loss.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from espnet(https://github.com/espnet/espnet)
 """Adversarial loss modules."""
 import paddle
 import paddle.nn.functional as F
diff --git a/paddlespeech/t2s/modules/fastspeech2_predictor/duration_predictor.py b/paddlespeech/t2s/modules/fastspeech2_predictor/duration_predictor.py
index eac7cf99..b269b686 100644
--- a/paddlespeech/t2s/modules/fastspeech2_predictor/duration_predictor.py
+++ b/paddlespeech/t2s/modules/fastspeech2_predictor/duration_predictor.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from espnet(https://github.com/espnet/espnet)
 """Duration predictor related modules."""
 import paddle
 from paddle import nn
diff --git a/paddlespeech/t2s/modules/fastspeech2_predictor/length_regulator.py b/paddlespeech/t2s/modules/fastspeech2_predictor/length_regulator.py
index a4d508ad..bf595b24 100644
--- a/paddlespeech/t2s/modules/fastspeech2_predictor/length_regulator.py
+++ b/paddlespeech/t2s/modules/fastspeech2_predictor/length_regulator.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from espnet(https://github.com/espnet/espnet)
 """Length regulator related modules."""
 import paddle
 from paddle import nn
diff --git a/paddlespeech/t2s/modules/fastspeech2_predictor/variance_predictor.py b/paddlespeech/t2s/modules/fastspeech2_predictor/variance_predictor.py
index 0fd108d3..417fca82 100644
--- a/paddlespeech/t2s/modules/fastspeech2_predictor/variance_predictor.py
+++ b/paddlespeech/t2s/modules/fastspeech2_predictor/variance_predictor.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from espnet(https://github.com/espnet/espnet)
 """Variance predictor related modules."""
 import paddle
 from paddle import nn
diff --git a/paddlespeech/t2s/modules/fastspeech2_transformer/attention.py b/paddlespeech/t2s/modules/fastspeech2_transformer/attention.py
index a61f1245..b11329b0 100644
--- a/paddlespeech/t2s/modules/fastspeech2_transformer/attention.py
+++ b/paddlespeech/t2s/modules/fastspeech2_transformer/attention.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from espnet(https://github.com/espnet/espnet)
 """Multi-Head Attention layer definition."""
 import math
 
diff --git a/paddlespeech/t2s/modules/fastspeech2_transformer/decoder.py b/paddlespeech/t2s/modules/fastspeech2_transformer/decoder.py
index c41e3995..489fda12 100644
--- a/paddlespeech/t2s/modules/fastspeech2_transformer/decoder.py
+++ b/paddlespeech/t2s/modules/fastspeech2_transformer/decoder.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from espnet(https://github.com/espnet/espnet)
 # 暂时删除了 dyminic conv
 """Decoder definition."""
 import logging
diff --git a/paddlespeech/t2s/modules/fastspeech2_transformer/decoder_layer.py b/paddlespeech/t2s/modules/fastspeech2_transformer/decoder_layer.py
index 9b042483..0310d83e 100644
--- a/paddlespeech/t2s/modules/fastspeech2_transformer/decoder_layer.py
+++ b/paddlespeech/t2s/modules/fastspeech2_transformer/decoder_layer.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from espnet(https://github.com/espnet/espnet)
 """Decoder self-attention layer definition."""
 import paddle
 from paddle import nn
diff --git a/paddlespeech/t2s/modules/fastspeech2_transformer/embedding.py b/paddlespeech/t2s/modules/fastspeech2_transformer/embedding.py
index 1dfd6dfd..f26c9dcb 100644
--- a/paddlespeech/t2s/modules/fastspeech2_transformer/embedding.py
+++ b/paddlespeech/t2s/modules/fastspeech2_transformer/embedding.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from espnet(https://github.com/espnet/espnet)
 """Positional Encoding Module."""
 import math
 
diff --git a/paddlespeech/t2s/modules/fastspeech2_transformer/encoder.py b/paddlespeech/t2s/modules/fastspeech2_transformer/encoder.py
index 904b9d8b..62d7a96f 100644
--- a/paddlespeech/t2s/modules/fastspeech2_transformer/encoder.py
+++ b/paddlespeech/t2s/modules/fastspeech2_transformer/encoder.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from espnet(https://github.com/espnet/espnet)
 import logging
 
 from paddle import nn
diff --git a/paddlespeech/t2s/modules/fastspeech2_transformer/encoder_layer.py b/paddlespeech/t2s/modules/fastspeech2_transformer/encoder_layer.py
index d8f89d67..fb2c2e82 100644
--- a/paddlespeech/t2s/modules/fastspeech2_transformer/encoder_layer.py
+++ b/paddlespeech/t2s/modules/fastspeech2_transformer/encoder_layer.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from espnet(https://github.com/espnet/espnet)
 """Encoder self-attention layer definition."""
 import paddle
 from paddle import nn
diff --git a/paddlespeech/t2s/modules/fastspeech2_transformer/lightconv.py b/paddlespeech/t2s/modules/fastspeech2_transformer/lightconv.py
index 3aceed31..1aeb6d6e 100644
--- a/paddlespeech/t2s/modules/fastspeech2_transformer/lightconv.py
+++ b/paddlespeech/t2s/modules/fastspeech2_transformer/lightconv.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from espnet(https://github.com/espnet/espnet)
 """Lightweight Convolution Module."""
 import numpy
 import paddle
diff --git a/paddlespeech/t2s/modules/fastspeech2_transformer/positionwise_feed_forward.py b/paddlespeech/t2s/modules/fastspeech2_transformer/positionwise_feed_forward.py
index 39c06eba..297a3b4f 100644
--- a/paddlespeech/t2s/modules/fastspeech2_transformer/positionwise_feed_forward.py
+++ b/paddlespeech/t2s/modules/fastspeech2_transformer/positionwise_feed_forward.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from espnet(https://github.com/espnet/espnet)
 """Positionwise feed forward layer definition."""
 import paddle
 
diff --git a/paddlespeech/t2s/modules/fastspeech2_transformer/repeat.py b/paddlespeech/t2s/modules/fastspeech2_transformer/repeat.py
index 3c62298e..0325a638 100644
--- a/paddlespeech/t2s/modules/fastspeech2_transformer/repeat.py
+++ b/paddlespeech/t2s/modules/fastspeech2_transformer/repeat.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from espnet(https://github.com/espnet/espnet)
 """Repeat the same layer definition."""
 import paddle
 
diff --git a/paddlespeech/t2s/modules/nets_utils.py b/paddlespeech/t2s/modules/nets_utils.py
index 0696335a..30d3db86 100644
--- a/paddlespeech/t2s/modules/nets_utils.py
+++ b/paddlespeech/t2s/modules/nets_utils.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from espnet(https://github.com/espnet/espnet)
 import paddle
 from paddle import nn
 from typeguard import check_argument_types
diff --git a/paddlespeech/t2s/modules/pqmf.py b/paddlespeech/t2s/modules/pqmf.py
index 70210e3b..c299fb57 100644
--- a/paddlespeech/t2s/modules/pqmf.py
+++ b/paddlespeech/t2s/modules/pqmf.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from espnet(https://github.com/espnet/espnet)
 """Pseudo QMF modules."""
 import numpy as np
 import paddle
diff --git a/paddlespeech/t2s/modules/residual_stack.py b/paddlespeech/t2s/modules/residual_stack.py
index 71bd4f0c..236f41d3 100644
--- a/paddlespeech/t2s/modules/residual_stack.py
+++ b/paddlespeech/t2s/modules/residual_stack.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from espnet(https://github.com/espnet/espnet)
 """Residual stack module in MelGAN."""
 from typing import Any
 from typing import Dict
diff --git a/paddlespeech/t2s/modules/stft_loss.py b/paddlespeech/t2s/modules/stft_loss.py
index 8af55ab1..31963e71 100644
--- a/paddlespeech/t2s/modules/stft_loss.py
+++ b/paddlespeech/t2s/modules/stft_loss.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from espnet(https://github.com/espnet/espnet)
 import paddle
 from paddle import nn
 from paddle.nn import functional as F
diff --git a/paddlespeech/t2s/modules/style_encoder.py b/paddlespeech/t2s/modules/style_encoder.py
index c6b12d44..868a73a9 100644
--- a/paddlespeech/t2s/modules/style_encoder.py
+++ b/paddlespeech/t2s/modules/style_encoder.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from espnet(https://github.com/espnet/espnet)
 """Style encoder of GST-Tacotron."""
 from typing import Sequence
 
diff --git a/paddlespeech/t2s/modules/tacotron2/decoder.py b/paddlespeech/t2s/modules/tacotron2/decoder.py
index 779fd0c6..691bb3ee 100644
--- a/paddlespeech/t2s/modules/tacotron2/decoder.py
+++ b/paddlespeech/t2s/modules/tacotron2/decoder.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from espnet(https://github.com/espnet/espnet)
 """Tacotron2 decoder related modules."""
 import paddle.nn.functional as F
 import six
diff --git a/paddlespeech/t2s/modules/tacotron2/encoder.py b/paddlespeech/t2s/modules/tacotron2/encoder.py
index 95f71d5e..b95e3529 100644
--- a/paddlespeech/t2s/modules/tacotron2/encoder.py
+++ b/paddlespeech/t2s/modules/tacotron2/encoder.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from espnet(https://github.com/espnet/espnet)
 """Tacotron2 encoder related modules."""
 import paddle
 import six
diff --git a/paddlespeech/t2s/training/extension.py b/paddlespeech/t2s/training/extension.py
index 07e92696..3f755a76 100644
--- a/paddlespeech/t2s/training/extension.py
+++ b/paddlespeech/t2s/training/extension.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from chainer(https://github.com/chainer/chainer)
 from typing import Callable
 
 PRIORITY_WRITER = 300
diff --git a/paddlespeech/t2s/training/extensions/evaluator.py b/paddlespeech/t2s/training/extensions/evaluator.py
index 28249d09..3940dffe 100644
--- a/paddlespeech/t2s/training/extensions/evaluator.py
+++ b/paddlespeech/t2s/training/extensions/evaluator.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from chainer(https://github.com/chainer/chainer)
 from typing import Dict
 
 import paddle
diff --git a/paddlespeech/t2s/training/extensions/snapshot.py b/paddlespeech/t2s/training/extensions/snapshot.py
index 2e401596..3a86556b 100644
--- a/paddlespeech/t2s/training/extensions/snapshot.py
+++ b/paddlespeech/t2s/training/extensions/snapshot.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from chainer(https://github.com/chainer/chainer)
 import logging
 import os
 from datetime import datetime
diff --git a/paddlespeech/t2s/training/reporter.py b/paddlespeech/t2s/training/reporter.py
index 013c754e..a61506da 100644
--- a/paddlespeech/t2s/training/reporter.py
+++ b/paddlespeech/t2s/training/reporter.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from chainer(https://github.com/chainer/chainer)
 import contextlib
 import math
 from collections import defaultdict
diff --git a/paddlespeech/t2s/training/triggers/interval_trigger.py b/paddlespeech/t2s/training/triggers/interval_trigger.py
index 98c03684..a83139ba 100644
--- a/paddlespeech/t2s/training/triggers/interval_trigger.py
+++ b/paddlespeech/t2s/training/triggers/interval_trigger.py
@@ -11,6 +11,7 @@
 # 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.
+# Reference chainer MIT (https://opensource.org/licenses/MIT)
 
 
 class IntervalTrigger(object):
diff --git a/paddlespeech/t2s/training/triggers/limit_trigger.py b/paddlespeech/t2s/training/triggers/limit_trigger.py
index dd7a135e..db1db774 100644
--- a/paddlespeech/t2s/training/triggers/limit_trigger.py
+++ b/paddlespeech/t2s/training/triggers/limit_trigger.py
@@ -11,6 +11,7 @@
 # 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.
+# Reference chainer MIT (https://opensource.org/licenses/MIT)
 
 
 class LimitTrigger(object):
diff --git a/paddlespeech/t2s/training/triggers/time_trigger.py b/paddlespeech/t2s/training/triggers/time_trigger.py
index aff93825..d7123524 100644
--- a/paddlespeech/t2s/training/triggers/time_trigger.py
+++ b/paddlespeech/t2s/training/triggers/time_trigger.py
@@ -11,6 +11,7 @@
 # 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.
+# Reference chainer MIT (https://opensource.org/licenses/MIT)
 
 
 class TimeTrigger(object):
diff --git a/paddlespeech/t2s/training/updater.py b/paddlespeech/t2s/training/updater.py
index 1db3d5f9..a7055031 100644
--- a/paddlespeech/t2s/training/updater.py
+++ b/paddlespeech/t2s/training/updater.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from chainer(https://github.com/chainer/chainer)
 import logging
 from dataclasses import dataclass
 
diff --git a/paddlespeech/t2s/training/updaters/standard_updater.py b/paddlespeech/t2s/training/updaters/standard_updater.py
index 2d00d196..b1c48620 100644
--- a/paddlespeech/t2s/training/updaters/standard_updater.py
+++ b/paddlespeech/t2s/training/updaters/standard_updater.py
@@ -11,6 +11,7 @@
 # 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.
+# Modified from chainer(https://github.com/chainer/chainer)
 import logging
 import time
 from typing import Dict