#!/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.modules.nets_utils import make_pad_mask import funasr.modules.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) 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