Zengwei Yao f18b539fbc
Add the upgraded Zipformer model (#1058)
* add the zipformer codes, copied from branch from_dan_scaled_adam_exp1119

* support model export with torch.jit.script

* update RESULTS.md

* support exporting streaming model with torch.jit.script

* add results of streaming models, with some minor changes

* update README.md

* add CI test

* update k2 version in requirements-ci.txt

* update pyproject.toml
2023-05-19 16:47:59 +08:00

67 lines
2.2 KiB
Python

# 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
from scaling import ScaledLinear
class Joiner(nn.Module):
def __init__(
self,
encoder_dim: int,
decoder_dim: int,
joiner_dim: int,
vocab_size: int,
):
super().__init__()
self.encoder_proj = ScaledLinear(encoder_dim, joiner_dim, initial_scale=0.25)
self.decoder_proj = ScaledLinear(decoder_dim, joiner_dim, initial_scale=0.25)
self.output_linear = nn.Linear(joiner_dim, vocab_size)
def forward(
self,
encoder_out: torch.Tensor,
decoder_out: torch.Tensor,
project_input: bool = True,
) -> torch.Tensor:
"""
Args:
encoder_out:
Output from the encoder. Its shape is (N, T, s_range, C).
decoder_out:
Output from the decoder. Its shape is (N, T, s_range, C).
project_input:
If true, apply input projections encoder_proj and decoder_proj.
If this is false, it is the user's responsibility to do this
manually.
Returns:
Return a tensor of shape (N, T, s_range, C).
"""
assert encoder_out.ndim == decoder_out.ndim, (encoder_out.shape, decoder_out.shape)
if project_input:
logit = self.encoder_proj(encoder_out) + self.decoder_proj(
decoder_out
)
else:
logit = encoder_out + decoder_out
logit = self.output_linear(torch.tanh(logit))
return logit