marcoyang1998 16a2748d6c
PromptASR for contextualized ASR with controllable style (#1250)
* Add PromptASR with BERT as text encoder

* Support using word-list based content prompts for context biasing

* Upload the pretrained models to huggingface

* Add usage example
2023-10-11 14:56:41 +08:00

87 lines
2.9 KiB
Python

# Copyright 2023 Xiaomi Corp. (authors: Xiaoyu Yang)
#
# 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,
context_dim: int = 512,
context_injection: bool = False,
):
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)
if context_injection:
self.context_proj = ScaledLinear(
context_dim, joiner_dim, initial_scale=0.25
)
else:
self.context_proj = None
def forward(
self,
encoder_out: torch.Tensor,
decoder_out: torch.Tensor,
context: torch.Tensor = None,
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).
context:
An embedding vector representing the previous context information
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 == 4
assert encoder_out.shape[:-1] == decoder_out.shape[:-1]
if project_input:
if context:
logit = (
self.encoder_proj(encoder_out)
+ self.decoder_proj(decoder_out)
+ self.context_proj(context)
)
else:
logit = self.encoder_proj(encoder_out) + self.decoder_proj(decoder_out)
else:
if context is not None:
logit = encoder_out + decoder_out + context.unsqueeze(1).unsqueeze(1)
else:
logit = encoder_out + decoder_out
logit = self.output_linear(torch.tanh(logit))
return logit