FunASR/funasr/models/ct_transformer_streaming/attention.py
2024-01-13 23:43:17 +08:00

1092 lines
42 KiB
Python

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
# Copyright 2019 Shigeki Karita
# Apache 2.0 (http://www.apache.org/licenses/LICENSE-2.0)
"""Multi-Head Attention layer definition."""
import math
import numpy
import torch
from torch import nn
from typing import Optional, Tuple
import torch.nn.functional as F
from funasr.models.transformer.utils.nets_utils import make_pad_mask
import funasr.models.lora.layers as lora
class MultiHeadedAttention(nn.Module):
"""Multi-Head Attention layer.
Args:
n_head (int): The number of heads.
n_feat (int): The number of features.
dropout_rate (float): Dropout rate.
"""
def __init__(self, n_head, n_feat, dropout_rate):
"""Construct an MultiHeadedAttention object."""
super(MultiHeadedAttention, self).__init__()
assert n_feat % n_head == 0
# We assume d_v always equals d_k
self.d_k = n_feat // n_head
self.h = n_head
self.linear_q = nn.Linear(n_feat, n_feat)
self.linear_k = nn.Linear(n_feat, n_feat)
self.linear_v = nn.Linear(n_feat, n_feat)
self.linear_out = nn.Linear(n_feat, n_feat)
self.attn = None
self.dropout = nn.Dropout(p=dropout_rate)
def forward_qkv(self, query, key, value):
"""Transform query, key and value.
Args:
query (torch.Tensor): Query tensor (#batch, time1, size).
key (torch.Tensor): Key tensor (#batch, time2, size).
value (torch.Tensor): Value tensor (#batch, time2, size).
Returns:
torch.Tensor: Transformed query tensor (#batch, n_head, time1, d_k).
torch.Tensor: Transformed key tensor (#batch, n_head, time2, d_k).
torch.Tensor: Transformed value tensor (#batch, n_head, time2, d_k).
"""
n_batch = query.size(0)
q = self.linear_q(query).view(n_batch, -1, self.h, self.d_k)
k = self.linear_k(key).view(n_batch, -1, self.h, self.d_k)
v = self.linear_v(value).view(n_batch, -1, self.h, self.d_k)
q = q.transpose(1, 2) # (batch, head, time1, d_k)
k = k.transpose(1, 2) # (batch, head, time2, d_k)
v = v.transpose(1, 2) # (batch, head, time2, d_k)
return q, k, v
def forward_attention(self, value, scores, mask):
"""Compute attention context vector.
Args:
value (torch.Tensor): Transformed value (#batch, n_head, time2, d_k).
scores (torch.Tensor): Attention score (#batch, n_head, time1, time2).
mask (torch.Tensor): Mask (#batch, 1, time2) or (#batch, time1, time2).
Returns:
torch.Tensor: Transformed value (#batch, time1, d_model)
weighted by the attention score (#batch, time1, time2).
"""
n_batch = value.size(0)
if mask is not None:
mask = mask.unsqueeze(1).eq(0) # (batch, 1, *, time2)
min_value = float(
numpy.finfo(torch.tensor(0, dtype=scores.dtype).numpy().dtype).min
)
scores = scores.masked_fill(mask, min_value)
self.attn = torch.softmax(scores, dim=-1).masked_fill(
mask, 0.0
) # (batch, head, time1, time2)
else:
self.attn = torch.softmax(scores, dim=-1) # (batch, head, time1, time2)
p_attn = self.dropout(self.attn)
x = torch.matmul(p_attn, value) # (batch, head, time1, d_k)
x = (
x.transpose(1, 2).contiguous().view(n_batch, -1, self.h * self.d_k)
) # (batch, time1, d_model)
return self.linear_out(x) # (batch, time1, d_model)
def forward(self, query, key, value, mask):
"""Compute scaled dot product attention.
Args:
query (torch.Tensor): Query tensor (#batch, time1, size).
key (torch.Tensor): Key tensor (#batch, time2, size).
value (torch.Tensor): Value tensor (#batch, time2, size).
mask (torch.Tensor): Mask tensor (#batch, 1, time2) or
(#batch, time1, time2).
Returns:
torch.Tensor: Output tensor (#batch, time1, d_model).
"""
q, k, v = self.forward_qkv(query, key, value)
scores = torch.matmul(q, k.transpose(-2, -1)) / math.sqrt(self.d_k)
return self.forward_attention(v, scores, mask)
class LegacyRelPositionMultiHeadedAttention(MultiHeadedAttention):
"""Multi-Head Attention layer with relative position encoding (old version).
Details can be found in https://github.com/espnet/espnet/pull/2816.
Paper: https://arxiv.org/abs/1901.02860
Args:
n_head (int): The number of heads.
n_feat (int): The number of features.
dropout_rate (float): Dropout rate.
zero_triu (bool): Whether to zero the upper triangular part of attention matrix.
"""
def __init__(self, n_head, n_feat, dropout_rate, zero_triu=False):
"""Construct an RelPositionMultiHeadedAttention object."""
super().__init__(n_head, n_feat, dropout_rate)
self.zero_triu = zero_triu
# linear transformation for positional encoding
self.linear_pos = nn.Linear(n_feat, n_feat, bias=False)
# these two learnable bias are used in matrix c and matrix d
# as described in https://arxiv.org/abs/1901.02860 Section 3.3
self.pos_bias_u = nn.Parameter(torch.Tensor(self.h, self.d_k))
self.pos_bias_v = nn.Parameter(torch.Tensor(self.h, self.d_k))
torch.nn.init.xavier_uniform_(self.pos_bias_u)
torch.nn.init.xavier_uniform_(self.pos_bias_v)
def rel_shift(self, x):
"""Compute relative positional encoding.
Args:
x (torch.Tensor): Input tensor (batch, head, time1, time2).
Returns:
torch.Tensor: Output tensor.
"""
zero_pad = torch.zeros((*x.size()[:3], 1), device=x.device, dtype=x.dtype)
x_padded = torch.cat([zero_pad, x], dim=-1)
x_padded = x_padded.view(*x.size()[:2], x.size(3) + 1, x.size(2))
x = x_padded[:, :, 1:].view_as(x)
if self.zero_triu:
ones = torch.ones((x.size(2), x.size(3)))
x = x * torch.tril(ones, x.size(3) - x.size(2))[None, None, :, :]
return x
def forward(self, query, key, value, pos_emb, mask):
"""Compute 'Scaled Dot Product Attention' with rel. positional encoding.
Args:
query (torch.Tensor): Query tensor (#batch, time1, size).
key (torch.Tensor): Key tensor (#batch, time2, size).
value (torch.Tensor): Value tensor (#batch, time2, size).
pos_emb (torch.Tensor): Positional embedding tensor (#batch, time1, size).
mask (torch.Tensor): Mask tensor (#batch, 1, time2) or
(#batch, time1, time2).
Returns:
torch.Tensor: Output tensor (#batch, time1, d_model).
"""
q, k, v = self.forward_qkv(query, key, value)
q = q.transpose(1, 2) # (batch, time1, head, d_k)
n_batch_pos = pos_emb.size(0)
p = self.linear_pos(pos_emb).view(n_batch_pos, -1, self.h, self.d_k)
p = p.transpose(1, 2) # (batch, head, time1, d_k)
# (batch, head, time1, 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)
# compute attention score
# first compute matrix a and matrix c
# as described in https://arxiv.org/abs/1901.02860 Section 3.3
# (batch, head, time1, time2)
matrix_ac = torch.matmul(q_with_bias_u, k.transpose(-2, -1))
# compute matrix b and matrix d
# (batch, head, time1, time1)
matrix_bd = torch.matmul(q_with_bias_v, p.transpose(-2, -1))
matrix_bd = self.rel_shift(matrix_bd)
scores = (matrix_ac + matrix_bd) / math.sqrt(
self.d_k
) # (batch, head, time1, time2)
return self.forward_attention(v, scores, mask)
class RelPositionMultiHeadedAttention(MultiHeadedAttention):
"""Multi-Head Attention layer with relative position encoding (new implementation).
Details can be found in https://github.com/espnet/espnet/pull/2816.
Paper: https://arxiv.org/abs/1901.02860
Args:
n_head (int): The number of heads.
n_feat (int): The number of features.
dropout_rate (float): Dropout rate.
zero_triu (bool): Whether to zero the upper triangular part of attention matrix.
"""
def __init__(self, n_head, n_feat, dropout_rate, zero_triu=False):
"""Construct an RelPositionMultiHeadedAttention object."""
super().__init__(n_head, n_feat, dropout_rate)
self.zero_triu = zero_triu
# linear transformation for positional encoding
self.linear_pos = nn.Linear(n_feat, n_feat, bias=False)
# these two learnable bias are used in matrix c and matrix d
# as described in https://arxiv.org/abs/1901.02860 Section 3.3
self.pos_bias_u = nn.Parameter(torch.Tensor(self.h, self.d_k))
self.pos_bias_v = nn.Parameter(torch.Tensor(self.h, self.d_k))
torch.nn.init.xavier_uniform_(self.pos_bias_u)
torch.nn.init.xavier_uniform_(self.pos_bias_v)
def rel_shift(self, x):
"""Compute relative positional encoding.
Args:
x (torch.Tensor): Input tensor (batch, head, time1, 2*time1-1).
time1 means the length of query vector.
Returns:
torch.Tensor: Output tensor.
"""
zero_pad = torch.zeros((*x.size()[:3], 1), device=x.device, dtype=x.dtype)
x_padded = torch.cat([zero_pad, x], dim=-1)
x_padded = x_padded.view(*x.size()[:2], x.size(3) + 1, x.size(2))
x = x_padded[:, :, 1:].view_as(x)[
:, :, :, : x.size(-1) // 2 + 1
] # only keep the positions from 0 to time2
if self.zero_triu:
ones = torch.ones((x.size(2), x.size(3)), device=x.device)
x = x * torch.tril(ones, x.size(3) - x.size(2))[None, None, :, :]
return x
def forward(self, query, key, value, pos_emb, mask):
"""Compute 'Scaled Dot Product Attention' with rel. positional encoding.
Args:
query (torch.Tensor): Query tensor (#batch, time1, size).
key (torch.Tensor): Key tensor (#batch, time2, size).
value (torch.Tensor): Value tensor (#batch, time2, size).
pos_emb (torch.Tensor): Positional embedding tensor
(#batch, 2*time1-1, size).
mask (torch.Tensor): Mask tensor (#batch, 1, time2) or
(#batch, time1, time2).
Returns:
torch.Tensor: Output tensor (#batch, time1, d_model).
"""
q, k, v = self.forward_qkv(query, key, value)
q = q.transpose(1, 2) # (batch, time1, head, d_k)
n_batch_pos = pos_emb.size(0)
p = self.linear_pos(pos_emb).view(n_batch_pos, -1, self.h, self.d_k)
p = p.transpose(1, 2) # (batch, head, 2*time1-1, d_k)
# (batch, head, time1, 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)
# compute attention score
# first compute matrix a and matrix c
# as described in https://arxiv.org/abs/1901.02860 Section 3.3
# (batch, head, time1, time2)
matrix_ac = torch.matmul(q_with_bias_u, k.transpose(-2, -1))
# compute matrix b and matrix d
# (batch, head, time1, 2*time1-1)
matrix_bd = torch.matmul(q_with_bias_v, p.transpose(-2, -1))
matrix_bd = self.rel_shift(matrix_bd)
scores = (matrix_ac + matrix_bd) / math.sqrt(
self.d_k
) # (batch, head, time1, time2)
return self.forward_attention(v, scores, mask)
class MultiHeadedAttentionSANM(nn.Module):
"""Multi-Head Attention layer.
Args:
n_head (int): The number of heads.
n_feat (int): The number of features.
dropout_rate (float): Dropout rate.
"""
def __init__(self, n_head, in_feat, n_feat, dropout_rate, kernel_size, sanm_shfit=0, lora_list=None, lora_rank=8, lora_alpha=16, lora_dropout=0.1):
"""Construct an MultiHeadedAttention object."""
super(MultiHeadedAttentionSANM, self).__init__()
assert n_feat % n_head == 0
# We assume d_v always equals d_k
self.d_k = n_feat // n_head
self.h = n_head
# self.linear_q = nn.Linear(n_feat, n_feat)
# self.linear_k = nn.Linear(n_feat, n_feat)
# self.linear_v = nn.Linear(n_feat, n_feat)
if lora_list is not None:
if "o" in lora_list:
self.linear_out = lora.Linear(n_feat, n_feat, r=lora_rank, lora_alpha=lora_alpha, lora_dropout=lora_dropout)
else:
self.linear_out = nn.Linear(n_feat, n_feat)
lora_qkv_list = ["q" in lora_list, "k" in lora_list, "v" in lora_list]
if lora_qkv_list == [False, False, False]:
self.linear_q_k_v = nn.Linear(in_feat, n_feat * 3)
else:
self.linear_q_k_v = lora.MergedLinear(in_feat, n_feat * 3, r=lora_rank, lora_alpha=lora_alpha, lora_dropout=lora_dropout, enable_lora=lora_qkv_list)
else:
self.linear_out = nn.Linear(n_feat, n_feat)
self.linear_q_k_v = nn.Linear(in_feat, n_feat * 3)
self.attn = None
self.dropout = nn.Dropout(p=dropout_rate)
self.fsmn_block = nn.Conv1d(n_feat, n_feat, kernel_size, stride=1, padding=0, groups=n_feat, bias=False)
# padding
left_padding = (kernel_size - 1) // 2
if sanm_shfit > 0:
left_padding = left_padding + sanm_shfit
right_padding = kernel_size - 1 - left_padding
self.pad_fn = nn.ConstantPad1d((left_padding, right_padding), 0.0)
def forward_fsmn(self, inputs, mask, mask_shfit_chunk=None):
b, t, d = inputs.size()
if mask is not None:
mask = torch.reshape(mask, (b, -1, 1))
if mask_shfit_chunk is not None:
mask = mask * mask_shfit_chunk
inputs = inputs * mask
x = inputs.transpose(1, 2)
x = self.pad_fn(x)
x = self.fsmn_block(x)
x = x.transpose(1, 2)
x += inputs
x = self.dropout(x)
if mask is not None:
x = x * mask
return x
def forward_qkv(self, x):
"""Transform query, key and value.
Args:
query (torch.Tensor): Query tensor (#batch, time1, size).
key (torch.Tensor): Key tensor (#batch, time2, size).
value (torch.Tensor): Value tensor (#batch, time2, size).
Returns:
torch.Tensor: Transformed query tensor (#batch, n_head, time1, d_k).
torch.Tensor: Transformed key tensor (#batch, n_head, time2, d_k).
torch.Tensor: Transformed value tensor (#batch, n_head, time2, d_k).
"""
b, t, d = x.size()
q_k_v = self.linear_q_k_v(x)
q, k, v = torch.split(q_k_v, int(self.h * self.d_k), dim=-1)
q_h = torch.reshape(q, (b, t, self.h, self.d_k)).transpose(1, 2) # (batch, head, time1, d_k)
k_h = torch.reshape(k, (b, t, self.h, self.d_k)).transpose(1, 2) # (batch, head, time2, d_k)
v_h = torch.reshape(v, (b, t, self.h, self.d_k)).transpose(1, 2) # (batch, head, time2, d_k)
return q_h, k_h, v_h, v
def forward_attention(self, value, scores, mask, mask_att_chunk_encoder=None):
"""Compute attention context vector.
Args:
value (torch.Tensor): Transformed value (#batch, n_head, time2, d_k).
scores (torch.Tensor): Attention score (#batch, n_head, time1, time2).
mask (torch.Tensor): Mask (#batch, 1, time2) or (#batch, time1, time2).
Returns:
torch.Tensor: Transformed value (#batch, time1, d_model)
weighted by the attention score (#batch, time1, time2).
"""
n_batch = value.size(0)
if mask is not None:
if mask_att_chunk_encoder is not None:
mask = mask * mask_att_chunk_encoder
mask = mask.unsqueeze(1).eq(0) # (batch, 1, *, time2)
min_value = float(
numpy.finfo(torch.tensor(0, dtype=scores.dtype).numpy().dtype).min
)
scores = scores.masked_fill(mask, min_value)
self.attn = torch.softmax(scores, dim=-1).masked_fill(
mask, 0.0
) # (batch, head, time1, time2)
else:
self.attn = torch.softmax(scores, dim=-1) # (batch, head, time1, time2)
p_attn = self.dropout(self.attn)
x = torch.matmul(p_attn, value) # (batch, head, time1, d_k)
x = (
x.transpose(1, 2).contiguous().view(n_batch, -1, self.h * self.d_k)
) # (batch, time1, d_model)
return self.linear_out(x) # (batch, time1, d_model)
def forward(self, x, mask, mask_shfit_chunk=None, mask_att_chunk_encoder=None):
"""Compute scaled dot product attention.
Args:
query (torch.Tensor): Query tensor (#batch, time1, size).
key (torch.Tensor): Key tensor (#batch, time2, size).
value (torch.Tensor): Value tensor (#batch, time2, size).
mask (torch.Tensor): Mask tensor (#batch, 1, time2) or
(#batch, time1, time2).
Returns:
torch.Tensor: Output tensor (#batch, time1, d_model).
"""
q_h, k_h, v_h, v = self.forward_qkv(x)
fsmn_memory = self.forward_fsmn(v, mask, mask_shfit_chunk)
q_h = q_h * self.d_k ** (-0.5)
scores = torch.matmul(q_h, k_h.transpose(-2, -1))
att_outs = self.forward_attention(v_h, scores, mask, mask_att_chunk_encoder)
return att_outs + fsmn_memory
def forward_chunk(self, x, cache=None, chunk_size=None, look_back=0):
"""Compute scaled dot product attention.
Args:
query (torch.Tensor): Query tensor (#batch, time1, size).
key (torch.Tensor): Key tensor (#batch, time2, size).
value (torch.Tensor): Value tensor (#batch, time2, size).
mask (torch.Tensor): Mask tensor (#batch, 1, time2) or
(#batch, time1, time2).
Returns:
torch.Tensor: Output tensor (#batch, time1, d_model).
"""
q_h, k_h, v_h, v = self.forward_qkv(x)
if chunk_size is not None and look_back > 0 or look_back == -1:
if cache is not None:
k_h_stride = k_h[:, :, :-(chunk_size[2]), :]
v_h_stride = v_h[:, :, :-(chunk_size[2]), :]
k_h = torch.cat((cache["k"], k_h), dim=2)
v_h = torch.cat((cache["v"], v_h), dim=2)
cache["k"] = torch.cat((cache["k"], k_h_stride), dim=2)
cache["v"] = torch.cat((cache["v"], v_h_stride), dim=2)
if look_back != -1:
cache["k"] = cache["k"][:, :, -(look_back * chunk_size[1]):, :]
cache["v"] = cache["v"][:, :, -(look_back * chunk_size[1]):, :]
else:
cache_tmp = {"k": k_h[:, :, :-(chunk_size[2]), :],
"v": v_h[:, :, :-(chunk_size[2]), :]}
cache = cache_tmp
fsmn_memory = self.forward_fsmn(v, None)
q_h = q_h * self.d_k ** (-0.5)
scores = torch.matmul(q_h, k_h.transpose(-2, -1))
att_outs = self.forward_attention(v_h, scores, None)
return att_outs + fsmn_memory, cache
class MultiHeadedAttentionSANMwithMask(MultiHeadedAttentionSANM):
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
def forward(self, x, mask, mask_shfit_chunk=None, mask_att_chunk_encoder=None):
q_h, k_h, v_h, v = self.forward_qkv(x)
fsmn_memory = self.forward_fsmn(v, mask[0], mask_shfit_chunk)
q_h = q_h * self.d_k ** (-0.5)
scores = torch.matmul(q_h, k_h.transpose(-2, -1))
att_outs = self.forward_attention(v_h, scores, mask[1], mask_att_chunk_encoder)
return att_outs + fsmn_memory
class MultiHeadedAttentionSANMDecoder(nn.Module):
"""Multi-Head Attention layer.
Args:
n_head (int): The number of heads.
n_feat (int): The number of features.
dropout_rate (float): Dropout rate.
"""
def __init__(self, n_feat, dropout_rate, kernel_size, sanm_shfit=0):
"""Construct an MultiHeadedAttention object."""
super(MultiHeadedAttentionSANMDecoder, self).__init__()
self.dropout = nn.Dropout(p=dropout_rate)
self.fsmn_block = nn.Conv1d(n_feat, n_feat,
kernel_size, stride=1, padding=0, groups=n_feat, bias=False)
# padding
# padding
left_padding = (kernel_size - 1) // 2
if sanm_shfit > 0:
left_padding = left_padding + sanm_shfit
right_padding = kernel_size - 1 - left_padding
self.pad_fn = nn.ConstantPad1d((left_padding, right_padding), 0.0)
self.kernel_size = kernel_size
def forward(self, inputs, mask, cache=None, mask_shfit_chunk=None):
'''
:param x: (#batch, time1, size).
:param mask: Mask tensor (#batch, 1, time)
:return:
'''
# print("in fsmn, inputs", inputs.size())
b, t, d = inputs.size()
# logging.info(
# "mask: {}".format(mask.size()))
if mask is not None:
mask = torch.reshape(mask, (b ,-1, 1))
# logging.info("in fsmn, mask: {}, {}".format(mask.size(), mask[0:100:50, :, :]))
if mask_shfit_chunk is not None:
# logging.info("in fsmn, mask_fsmn: {}, {}".format(mask_shfit_chunk.size(), mask_shfit_chunk[0:100:50, :, :]))
mask = mask * mask_shfit_chunk
# logging.info("in fsmn, mask_after_fsmn: {}, {}".format(mask.size(), mask[0:100:50, :, :]))
# print("in fsmn, mask", mask.size())
# print("in fsmn, inputs", inputs.size())
inputs = inputs * mask
x = inputs.transpose(1, 2)
b, d, t = x.size()
if cache is None:
# print("in fsmn, cache is None, x", x.size())
x = self.pad_fn(x)
if not self.training:
cache = x
else:
# print("in fsmn, cache is not None, x", x.size())
# x = torch.cat((x, cache), dim=2)[:, :, :-1]
# if t < self.kernel_size:
# x = self.pad_fn(x)
x = torch.cat((cache[:, :, 1:], x), dim=2)
x = x[:, :, -(self.kernel_size+t-1):]
# print("in fsmn, cache is not None, x_cat", x.size())
cache = x
x = self.fsmn_block(x)
x = x.transpose(1, 2)
# print("in fsmn, fsmn_out", x.size())
if x.size(1) != inputs.size(1):
inputs = inputs[:, -1, :]
x = x + inputs
x = self.dropout(x)
if mask is not None:
x = x * mask
return x, cache
class MultiHeadedAttentionCrossAtt(nn.Module):
"""Multi-Head Attention layer.
Args:
n_head (int): The number of heads.
n_feat (int): The number of features.
dropout_rate (float): Dropout rate.
"""
def __init__(self, n_head, n_feat, dropout_rate, lora_list=None, lora_rank=8, lora_alpha=16, lora_dropout=0.1, encoder_output_size=None):
"""Construct an MultiHeadedAttention object."""
super(MultiHeadedAttentionCrossAtt, self).__init__()
assert n_feat % n_head == 0
# We assume d_v always equals d_k
self.d_k = n_feat // n_head
self.h = n_head
if lora_list is not None:
if "q" in lora_list:
self.linear_q = lora.Linear(n_feat, n_feat, r=lora_rank, lora_alpha=lora_alpha, lora_dropout=lora_dropout)
else:
self.linear_q = nn.Linear(n_feat, n_feat)
lora_kv_list = ["k" in lora_list, "v" in lora_list]
if lora_kv_list == [False, False]:
self.linear_k_v = nn.Linear(n_feat if encoder_output_size is None else encoder_output_size, n_feat*2)
else:
self.linear_k_v = lora.MergedLinear(n_feat if encoder_output_size is None else encoder_output_size, n_feat * 2,
r=lora_rank, lora_alpha=lora_alpha, lora_dropout=lora_dropout, enable_lora=lora_kv_list)
if "o" in lora_list:
self.linear_out = lora.Linear(n_feat, n_feat, r=lora_rank, lora_alpha=lora_alpha, lora_dropout=lora_dropout)
else:
self.linear_out = nn.Linear(n_feat, n_feat)
else:
self.linear_q = nn.Linear(n_feat, n_feat)
self.linear_k_v = nn.Linear(n_feat if encoder_output_size is None else encoder_output_size, n_feat*2)
self.linear_out = nn.Linear(n_feat, n_feat)
self.attn = None
self.dropout = nn.Dropout(p=dropout_rate)
def forward_qkv(self, x, memory):
"""Transform query, key and value.
Args:
query (torch.Tensor): Query tensor (#batch, time1, size).
key (torch.Tensor): Key tensor (#batch, time2, size).
value (torch.Tensor): Value tensor (#batch, time2, size).
Returns:
torch.Tensor: Transformed query tensor (#batch, n_head, time1, d_k).
torch.Tensor: Transformed key tensor (#batch, n_head, time2, d_k).
torch.Tensor: Transformed value tensor (#batch, n_head, time2, d_k).
"""
# print("in forward_qkv, x", x.size())
b = x.size(0)
q = self.linear_q(x)
q_h = torch.reshape(q, (b, -1, self.h, self.d_k)).transpose(1, 2) # (batch, head, time1, d_k)
k_v = self.linear_k_v(memory)
k, v = torch.split(k_v, int(self.h*self.d_k), dim=-1)
k_h = torch.reshape(k, (b, -1, self.h, self.d_k)).transpose(1, 2) # (batch, head, time2, d_k)
v_h = torch.reshape(v, (b, -1, self.h, self.d_k)).transpose(1, 2) # (batch, head, time2, d_k)
return q_h, k_h, v_h
def forward_attention(self, value, scores, mask):
"""Compute attention context vector.
Args:
value (torch.Tensor): Transformed value (#batch, n_head, time2, d_k).
scores (torch.Tensor): Attention score (#batch, n_head, time1, time2).
mask (torch.Tensor): Mask (#batch, 1, time2) or (#batch, time1, time2).
Returns:
torch.Tensor: Transformed value (#batch, time1, d_model)
weighted by the attention score (#batch, time1, time2).
"""
n_batch = value.size(0)
if mask is not None:
mask = mask.unsqueeze(1).eq(0) # (batch, 1, *, time2)
min_value = float(
numpy.finfo(torch.tensor(0, dtype=scores.dtype).numpy().dtype).min
)
# logging.info(
# "scores: {}, mask_size: {}".format(scores.size(), mask.size()))
scores = scores.masked_fill(mask, min_value)
self.attn = torch.softmax(scores, dim=-1).masked_fill(
mask, 0.0
) # (batch, head, time1, time2)
else:
self.attn = torch.softmax(scores, dim=-1) # (batch, head, time1, time2)
p_attn = self.dropout(self.attn)
x = torch.matmul(p_attn, value) # (batch, head, time1, d_k)
x = (
x.transpose(1, 2).contiguous().view(n_batch, -1, self.h * self.d_k)
) # (batch, time1, d_model)
return self.linear_out(x) # (batch, time1, d_model)
def forward(self, x, memory, memory_mask):
"""Compute scaled dot product attention.
Args:
query (torch.Tensor): Query tensor (#batch, time1, size).
key (torch.Tensor): Key tensor (#batch, time2, size).
value (torch.Tensor): Value tensor (#batch, time2, size).
mask (torch.Tensor): Mask tensor (#batch, 1, time2) or
(#batch, time1, time2).
Returns:
torch.Tensor: Output tensor (#batch, time1, d_model).
"""
q_h, k_h, v_h = self.forward_qkv(x, memory)
q_h = q_h * self.d_k ** (-0.5)
scores = torch.matmul(q_h, k_h.transpose(-2, -1))
return self.forward_attention(v_h, scores, memory_mask)
def forward_chunk(self, x, memory, cache=None, chunk_size=None, look_back=0):
"""Compute scaled dot product attention.
Args:
query (torch.Tensor): Query tensor (#batch, time1, size).
key (torch.Tensor): Key tensor (#batch, time2, size).
value (torch.Tensor): Value tensor (#batch, time2, size).
mask (torch.Tensor): Mask tensor (#batch, 1, time2) or
(#batch, time1, time2).
Returns:
torch.Tensor: Output tensor (#batch, time1, d_model).
"""
q_h, k_h, v_h = self.forward_qkv(x, memory)
if chunk_size is not None and look_back > 0:
if cache is not None:
k_h = torch.cat((cache["k"], k_h), dim=2)
v_h = torch.cat((cache["v"], v_h), dim=2)
cache["k"] = k_h[:, :, -(look_back * chunk_size[1]):, :]
cache["v"] = v_h[:, :, -(look_back * chunk_size[1]):, :]
else:
cache_tmp = {"k": k_h[:, :, -(look_back * chunk_size[1]):, :],
"v": v_h[:, :, -(look_back * chunk_size[1]):, :]}
cache = cache_tmp
q_h = q_h * self.d_k ** (-0.5)
scores = torch.matmul(q_h, k_h.transpose(-2, -1))
return self.forward_attention(v_h, scores, None), cache
class MultiHeadSelfAttention(nn.Module):
"""Multi-Head Attention layer.
Args:
n_head (int): The number of heads.
n_feat (int): The number of features.
dropout_rate (float): Dropout rate.
"""
def __init__(self, n_head, in_feat, n_feat, dropout_rate):
"""Construct an MultiHeadedAttention object."""
super(MultiHeadSelfAttention, self).__init__()
assert n_feat % n_head == 0
# We assume d_v always equals d_k
self.d_k = n_feat // n_head
self.h = n_head
self.linear_out = nn.Linear(n_feat, n_feat)
self.linear_q_k_v = nn.Linear(in_feat, n_feat * 3)
self.attn = None
self.dropout = nn.Dropout(p=dropout_rate)
def forward_qkv(self, x):
"""Transform query, key and value.
Args:
query (torch.Tensor): Query tensor (#batch, time1, size).
key (torch.Tensor): Key tensor (#batch, time2, size).
value (torch.Tensor): Value tensor (#batch, time2, size).
Returns:
torch.Tensor: Transformed query tensor (#batch, n_head, time1, d_k).
torch.Tensor: Transformed key tensor (#batch, n_head, time2, d_k).
torch.Tensor: Transformed value tensor (#batch, n_head, time2, d_k).
"""
b, t, d = x.size()
q_k_v = self.linear_q_k_v(x)
q, k, v = torch.split(q_k_v, int(self.h * self.d_k), dim=-1)
q_h = torch.reshape(q, (b, t, self.h, self.d_k)).transpose(1, 2) # (batch, head, time1, d_k)
k_h = torch.reshape(k, (b, t, self.h, self.d_k)).transpose(1, 2) # (batch, head, time2, d_k)
v_h = torch.reshape(v, (b, t, self.h, self.d_k)).transpose(1, 2) # (batch, head, time2, d_k)
return q_h, k_h, v_h, v
def forward_attention(self, value, scores, mask, mask_att_chunk_encoder=None):
"""Compute attention context vector.
Args:
value (torch.Tensor): Transformed value (#batch, n_head, time2, d_k).
scores (torch.Tensor): Attention score (#batch, n_head, time1, time2).
mask (torch.Tensor): Mask (#batch, 1, time2) or (#batch, time1, time2).
Returns:
torch.Tensor: Transformed value (#batch, time1, d_model)
weighted by the attention score (#batch, time1, time2).
"""
n_batch = value.size(0)
if mask is not None:
if mask_att_chunk_encoder is not None:
mask = mask * mask_att_chunk_encoder
mask = mask.unsqueeze(1).eq(0) # (batch, 1, *, time2)
min_value = float(
numpy.finfo(torch.tensor(0, dtype=scores.dtype).numpy().dtype).min
)
scores = scores.masked_fill(mask, min_value)
self.attn = torch.softmax(scores, dim=-1).masked_fill(
mask, 0.0
) # (batch, head, time1, time2)
else:
self.attn = torch.softmax(scores, dim=-1) # (batch, head, time1, time2)
p_attn = self.dropout(self.attn)
x = torch.matmul(p_attn, value) # (batch, head, time1, d_k)
x = (
x.transpose(1, 2).contiguous().view(n_batch, -1, self.h * self.d_k)
) # (batch, time1, d_model)
return self.linear_out(x) # (batch, time1, d_model)
def forward(self, x, mask, mask_att_chunk_encoder=None):
"""Compute scaled dot product attention.
Args:
query (torch.Tensor): Query tensor (#batch, time1, size).
key (torch.Tensor): Key tensor (#batch, time2, size).
value (torch.Tensor): Value tensor (#batch, time2, size).
mask (torch.Tensor): Mask tensor (#batch, 1, time2) or
(#batch, time1, time2).
Returns:
torch.Tensor: Output tensor (#batch, time1, d_model).
"""
q_h, k_h, v_h, v = self.forward_qkv(x)
q_h = q_h * self.d_k ** (-0.5)
scores = torch.matmul(q_h, k_h.transpose(-2, -1))
att_outs = self.forward_attention(v_h, scores, mask, mask_att_chunk_encoder)
return att_outs
class RelPositionMultiHeadedAttentionChunk(torch.nn.Module):
"""RelPositionMultiHeadedAttention definition.
Args:
num_heads: Number of attention heads.
embed_size: Embedding size.
dropout_rate: Dropout rate.
"""
def __init__(
self,
num_heads: int,
embed_size: int,
dropout_rate: float = 0.0,
simplified_attention_score: bool = False,
) -> None:
"""Construct an MultiHeadedAttention object."""
super().__init__()
self.d_k = embed_size // num_heads
self.num_heads = num_heads
assert self.d_k * num_heads == embed_size, (
"embed_size (%d) must be divisible by num_heads (%d)",
(embed_size, num_heads),
)
self.linear_q = torch.nn.Linear(embed_size, embed_size)
self.linear_k = torch.nn.Linear(embed_size, embed_size)
self.linear_v = torch.nn.Linear(embed_size, embed_size)
self.linear_out = torch.nn.Linear(embed_size, embed_size)
if simplified_attention_score:
self.linear_pos = torch.nn.Linear(embed_size, num_heads)
self.compute_att_score = self.compute_simplified_attention_score
else:
self.linear_pos = torch.nn.Linear(embed_size, embed_size, bias=False)
self.pos_bias_u = torch.nn.Parameter(torch.Tensor(num_heads, self.d_k))
self.pos_bias_v = torch.nn.Parameter(torch.Tensor(num_heads, self.d_k))
torch.nn.init.xavier_uniform_(self.pos_bias_u)
torch.nn.init.xavier_uniform_(self.pos_bias_v)
self.compute_att_score = self.compute_attention_score
self.dropout = torch.nn.Dropout(p=dropout_rate)
self.attn = None
def rel_shift(self, x: torch.Tensor, left_context: int = 0) -> torch.Tensor:
"""Compute relative positional encoding.
Args:
x: Input sequence. (B, H, T_1, 2 * T_1 - 1)
left_context: Number of frames in left context.
Returns:
x: Output sequence. (B, H, T_1, T_2)
"""
batch_size, n_heads, time1, n = x.shape
time2 = time1 + left_context
batch_stride, n_heads_stride, time1_stride, n_stride = x.stride()
return x.as_strided(
(batch_size, n_heads, time1, time2),
(batch_stride, n_heads_stride, time1_stride - n_stride, n_stride),
storage_offset=(n_stride * (time1 - 1)),
)
def compute_simplified_attention_score(
self,
query: torch.Tensor,
key: torch.Tensor,
pos_enc: torch.Tensor,
left_context: int = 0,
) -> torch.Tensor:
"""Simplified attention score computation.
Reference: https://github.com/k2-fsa/icefall/pull/458
Args:
query: Transformed query tensor. (B, H, T_1, d_k)
key: Transformed key tensor. (B, H, T_2, d_k)
pos_enc: Positional embedding tensor. (B, 2 * T_1 - 1, size)
left_context: Number of frames in left context.
Returns:
: Attention score. (B, H, T_1, T_2)
"""
pos_enc = self.linear_pos(pos_enc)
matrix_ac = torch.matmul(query, key.transpose(2, 3))
matrix_bd = self.rel_shift(
pos_enc.transpose(1, 2).unsqueeze(2).repeat(1, 1, query.size(2), 1),
left_context=left_context,
)
return (matrix_ac + matrix_bd) / math.sqrt(self.d_k)
def compute_attention_score(
self,
query: torch.Tensor,
key: torch.Tensor,
pos_enc: torch.Tensor,
left_context: int = 0,
) -> torch.Tensor:
"""Attention score computation.
Args:
query: Transformed query tensor. (B, H, T_1, d_k)
key: Transformed key tensor. (B, H, T_2, d_k)
pos_enc: Positional embedding tensor. (B, 2 * T_1 - 1, size)
left_context: Number of frames in left context.
Returns:
: Attention score. (B, H, T_1, T_2)
"""
p = self.linear_pos(pos_enc).view(pos_enc.size(0), -1, self.num_heads, self.d_k)
query = query.transpose(1, 2)
q_with_bias_u = (query + self.pos_bias_u).transpose(1, 2)
q_with_bias_v = (query + self.pos_bias_v).transpose(1, 2)
matrix_ac = torch.matmul(q_with_bias_u, key.transpose(-2, -1))
matrix_bd = torch.matmul(q_with_bias_v, p.permute(0, 2, 3, 1))
matrix_bd = self.rel_shift(matrix_bd, left_context=left_context)
return (matrix_ac + matrix_bd) / math.sqrt(self.d_k)
def forward_qkv(
self, query: torch.Tensor, key: torch.Tensor, value: torch.Tensor
) -> Tuple[torch.Tensor, torch.Tensor, torch.Tensor]:
"""Transform query, key and value.
Args:
query: Query tensor. (B, T_1, size)
key: Key tensor. (B, T_2, size)
v: Value tensor. (B, T_2, size)
Returns:
q: Transformed query tensor. (B, H, T_1, d_k)
k: Transformed key tensor. (B, H, T_2, d_k)
v: Transformed value tensor. (B, H, T_2, d_k)
"""
n_batch = query.size(0)
q = (
self.linear_q(query)
.view(n_batch, -1, self.num_heads, self.d_k)
.transpose(1, 2)
)
k = (
self.linear_k(key)
.view(n_batch, -1, self.num_heads, self.d_k)
.transpose(1, 2)
)
v = (
self.linear_v(value)
.view(n_batch, -1, self.num_heads, self.d_k)
.transpose(1, 2)
)
return q, k, v
def forward_attention(
self,
value: torch.Tensor,
scores: torch.Tensor,
mask: torch.Tensor,
chunk_mask: Optional[torch.Tensor] = None,
) -> torch.Tensor:
"""Compute attention context vector.
Args:
value: Transformed value. (B, H, T_2, d_k)
scores: Attention score. (B, H, T_1, T_2)
mask: Source mask. (B, T_2)
chunk_mask: Chunk mask. (T_1, T_1)
Returns:
attn_output: Transformed value weighted by attention score. (B, T_1, H * d_k)
"""
batch_size = scores.size(0)
mask = mask.unsqueeze(1).unsqueeze(2)
if chunk_mask is not None:
mask = chunk_mask.unsqueeze(0).unsqueeze(1) | mask
scores = scores.masked_fill(mask, float("-inf"))
self.attn = torch.softmax(scores, dim=-1).masked_fill(mask, 0.0)
attn_output = self.dropout(self.attn)
attn_output = torch.matmul(attn_output, value)
attn_output = self.linear_out(
attn_output.transpose(1, 2)
.contiguous()
.view(batch_size, -1, self.num_heads * self.d_k)
)
return attn_output
def forward(
self,
query: torch.Tensor,
key: torch.Tensor,
value: torch.Tensor,
pos_enc: torch.Tensor,
mask: torch.Tensor,
chunk_mask: Optional[torch.Tensor] = None,
left_context: int = 0,
) -> torch.Tensor:
"""Compute scaled dot product attention with rel. positional encoding.
Args:
query: Query tensor. (B, T_1, size)
key: Key tensor. (B, T_2, size)
value: Value tensor. (B, T_2, size)
pos_enc: Positional embedding tensor. (B, 2 * T_1 - 1, size)
mask: Source mask. (B, T_2)
chunk_mask: Chunk mask. (T_1, T_1)
left_context: Number of frames in left context.
Returns:
: Output tensor. (B, T_1, H * d_k)
"""
q, k, v = self.forward_qkv(query, key, value)
scores = self.compute_att_score(q, k, pos_enc, left_context=left_context)
return self.forward_attention(v, scores, mask, chunk_mask=chunk_mask)
class CosineDistanceAttention(nn.Module):
""" Compute Cosine Distance between spk decoder output and speaker profile
Args:
profile_path: speaker profile file path (.npy file)
"""
def __init__(self):
super().__init__()
self.softmax = nn.Softmax(dim=-1)
def forward(self, spk_decoder_out, profile, profile_lens=None):
"""
Args:
spk_decoder_out(torch.Tensor):(B, L, D)
spk_profiles(torch.Tensor):(B, N, D)
"""
x = spk_decoder_out.unsqueeze(2) # (B, L, 1, D)
if profile_lens is not None:
mask = (make_pad_mask(profile_lens)[:, None, :]).to(profile.device)
min_value = float(
numpy.finfo(torch.tensor(0, dtype=x.dtype).numpy().dtype).min
)
weights_not_softmax=F.cosine_similarity(x, profile.unsqueeze(1), dim=-1).masked_fill(mask, min_value)
weights = self.softmax(weights_not_softmax).masked_fill(mask, 0.0) # (B, L, N)
else:
x = x[:, -1:, :, :]
weights_not_softmax=F.cosine_similarity(x, profile.unsqueeze(1).to(x.device), dim=-1)
weights = self.softmax(weights_not_softmax) # (B, 1, N)
spk_embedding = torch.matmul(weights, profile.to(weights.device)) # (B, L, D)
return spk_embedding, weights