diff --git a/egs/librispeech/ASR/conformer_ctc_embedding_scale/README.md b/egs/librispeech/ASR/conformer_ctc_embedding_scale/README.md new file mode 100644 index 000000000..5106f28cf --- /dev/null +++ b/egs/librispeech/ASR/conformer_ctc_embedding_scale/README.md @@ -0,0 +1,31 @@ +## Differences between `conformer_ctc` and `conformer_ctc_embedding_scale` + +`conformer_ctc_embedding_scale` replaces `nn.Embedding` with modified +`Embedding`. Modified embedding contains two changes: + + - (1) The weight matrix is initialized to the range `(-std, std)` where + `std = 1 / sqrt(embedding_dim)` + + - (2) The output of the embedding is scaled by `sqrt(embedding_dim)` + +Also, `conformer_ctc_embedding_scale` modifies the `PositionalEncoding` +in `transformer.py`. It replaces + +```python +self.xscale = math.sqrt(self.d_model) +x = x * self.xscale + self.pe[:, : x.size(1), :] +``` +with + +```python +self.pos_scale = 1. / math.sqrt(self.d_model) +x = x + self.pe[:, : x.size(1), :] * self.pos_scale +``` + +You can use + +```bash +diff conformer_ctc/transformer.py conformer_ctc_embedding_scale/transformer.py +``` + +to find the exact differences. diff --git a/egs/librispeech/ASR/conformer_ctc_embedding_scale/__init__.py b/egs/librispeech/ASR/conformer_ctc_embedding_scale/__init__.py new file mode 100644 index 000000000..e69de29bb diff --git a/egs/librispeech/ASR/conformer_ctc_embedding_scale/asr_datamodule.py b/egs/librispeech/ASR/conformer_ctc_embedding_scale/asr_datamodule.py new file mode 120000 index 000000000..fa1b8cca3 --- /dev/null +++ b/egs/librispeech/ASR/conformer_ctc_embedding_scale/asr_datamodule.py @@ -0,0 +1 @@ +../tdnn_lstm_ctc/asr_datamodule.py \ No newline at end of file diff --git a/egs/librispeech/ASR/conformer_ctc_embedding_scale/conformer.py b/egs/librispeech/ASR/conformer_ctc_embedding_scale/conformer.py new file mode 100644 index 000000000..a00664a99 --- /dev/null +++ b/egs/librispeech/ASR/conformer_ctc_embedding_scale/conformer.py @@ -0,0 +1,920 @@ +#!/usr/bin/env python3 + +# Copyright (c) 2021 University of Chinese Academy of Sciences (author: Han Zhu) +# Apache 2.0 + +import math +import warnings +from typing import Optional, Tuple + +import torch +from torch import Tensor, nn +from transformer import Supervisions, Transformer, encoder_padding_mask + + +class Conformer(Transformer): + """ + Args: + num_features (int): Number of input features + num_classes (int): Number of output classes + subsampling_factor (int): subsampling factor of encoder (the convolution layers before transformers) + d_model (int): attention dimension + nhead (int): number of head + dim_feedforward (int): feedforward dimention + num_encoder_layers (int): number of encoder layers + num_decoder_layers (int): number of decoder layers + dropout (float): dropout rate + cnn_module_kernel (int): Kernel size of convolution module + normalize_before (bool): whether to use layer_norm before the first block. + vgg_frontend (bool): whether to use vgg frontend. + """ + + def __init__( + self, + num_features: int, + num_classes: int, + subsampling_factor: int = 4, + d_model: int = 256, + nhead: int = 4, + dim_feedforward: int = 2048, + num_encoder_layers: int = 12, + num_decoder_layers: int = 6, + dropout: float = 0.1, + cnn_module_kernel: int = 31, + normalize_before: bool = True, + vgg_frontend: bool = False, + is_espnet_structure: bool = False, + mmi_loss: bool = True, + use_feat_batchnorm: bool = False, + ) -> None: + super(Conformer, self).__init__( + num_features=num_features, + num_classes=num_classes, + subsampling_factor=subsampling_factor, + d_model=d_model, + nhead=nhead, + dim_feedforward=dim_feedforward, + num_encoder_layers=num_encoder_layers, + num_decoder_layers=num_decoder_layers, + dropout=dropout, + normalize_before=normalize_before, + vgg_frontend=vgg_frontend, + mmi_loss=mmi_loss, + use_feat_batchnorm=use_feat_batchnorm, + ) + + self.encoder_pos = RelPositionalEncoding(d_model, dropout) + + encoder_layer = ConformerEncoderLayer( + d_model, + nhead, + dim_feedforward, + dropout, + cnn_module_kernel, + normalize_before, + is_espnet_structure, + ) + self.encoder = ConformerEncoder(encoder_layer, num_encoder_layers) + self.normalize_before = normalize_before + self.is_espnet_structure = is_espnet_structure + if self.normalize_before and self.is_espnet_structure: + self.after_norm = nn.LayerNorm(d_model) + else: + # Note: TorchScript detects that self.after_norm could be used inside forward() + # and throws an error without this change. + self.after_norm = identity + + def run_encoder( + self, x: Tensor, supervisions: Optional[Supervisions] = None + ) -> Tuple[Tensor, Optional[Tensor]]: + """ + Args: + x: + The model input. Its shape is [N, T, C]. + supervisions: + Supervision in lhotse format. + See https://github.com/lhotse-speech/lhotse/blob/master/lhotse/dataset/speech_recognition.py#L32 # noqa + CAUTION: It contains length information, i.e., start and number of + frames, before subsampling + It is read directly from the batch, without any sorting. It is used + to compute encoder padding mask, which is used as memory key padding + mask for the decoder. + + Returns: + Tensor: Predictor tensor of dimension (input_length, batch_size, d_model). + Tensor: Mask tensor of dimension (batch_size, input_length) + """ + x = self.encoder_embed(x) + x, pos_emb = self.encoder_pos(x) + x = x.permute(1, 0, 2) # (B, T, F) -> (T, B, F) + mask = encoder_padding_mask(x.size(0), supervisions) + if mask is not None: + mask = mask.to(x.device) + x = self.encoder(x, pos_emb, src_key_padding_mask=mask) # (T, B, F) + + if self.normalize_before and self.is_espnet_structure: + x = self.after_norm(x) + + return x, mask + + +class ConformerEncoderLayer(nn.Module): + """ + ConformerEncoderLayer is made up of self-attn, feedforward and convolution networks. + See: "Conformer: Convolution-augmented Transformer for Speech Recognition" + + Args: + d_model: the number of expected features in the input (required). + nhead: the number of heads in the multiheadattention models (required). + dim_feedforward: the dimension of the feedforward network model (default=2048). + dropout: the dropout value (default=0.1). + cnn_module_kernel (int): Kernel size of convolution module. + normalize_before: whether to use layer_norm before the first block. + + Examples:: + >>> encoder_layer = ConformerEncoderLayer(d_model=512, nhead=8) + >>> src = torch.rand(10, 32, 512) + >>> pos_emb = torch.rand(32, 19, 512) + >>> out = encoder_layer(src, pos_emb) + """ + + def __init__( + self, + d_model: int, + nhead: int, + dim_feedforward: int = 2048, + dropout: float = 0.1, + cnn_module_kernel: int = 31, + normalize_before: bool = True, + is_espnet_structure: bool = False, + ) -> None: + super(ConformerEncoderLayer, self).__init__() + self.self_attn = RelPositionMultiheadAttention( + d_model, nhead, dropout=0.0, is_espnet_structure=is_espnet_structure + ) + + self.feed_forward = nn.Sequential( + nn.Linear(d_model, dim_feedforward), + Swish(), + nn.Dropout(dropout), + nn.Linear(dim_feedforward, d_model), + ) + + self.feed_forward_macaron = nn.Sequential( + nn.Linear(d_model, dim_feedforward), + Swish(), + nn.Dropout(dropout), + nn.Linear(dim_feedforward, d_model), + ) + + self.conv_module = ConvolutionModule(d_model, cnn_module_kernel) + + self.norm_ff_macaron = nn.LayerNorm( + d_model + ) # for the macaron style FNN module + self.norm_ff = nn.LayerNorm(d_model) # for the FNN module + self.norm_mha = nn.LayerNorm(d_model) # for the MHA module + + self.ff_scale = 0.5 + + self.norm_conv = nn.LayerNorm(d_model) # for the CNN module + self.norm_final = nn.LayerNorm( + d_model + ) # for the final output of the block + + self.dropout = nn.Dropout(dropout) + + self.normalize_before = normalize_before + + def forward( + self, + src: Tensor, + pos_emb: Tensor, + src_mask: Optional[Tensor] = None, + src_key_padding_mask: Optional[Tensor] = None, + ) -> Tensor: + """ + Pass the input through the encoder layer. + + Args: + src: the sequence to the encoder layer (required). + pos_emb: Positional embedding tensor (required). + src_mask: the mask for the src sequence (optional). + src_key_padding_mask: the mask for the src keys per batch (optional). + + Shape: + src: (S, N, E). + pos_emb: (N, 2*S-1, E) + src_mask: (S, S). + src_key_padding_mask: (N, S). + S is the source sequence length, N is the batch size, E is the feature number + """ + + # macaron style feed forward module + residual = src + if self.normalize_before: + src = self.norm_ff_macaron(src) + src = residual + self.ff_scale * self.dropout( + self.feed_forward_macaron(src) + ) + if not self.normalize_before: + src = self.norm_ff_macaron(src) + + # multi-headed self-attention module + residual = src + if self.normalize_before: + src = self.norm_mha(src) + src_att = self.self_attn( + src, + src, + src, + pos_emb=pos_emb, + attn_mask=src_mask, + key_padding_mask=src_key_padding_mask, + )[0] + src = residual + self.dropout(src_att) + if not self.normalize_before: + src = self.norm_mha(src) + + # convolution module + residual = src + if self.normalize_before: + src = self.norm_conv(src) + src = residual + self.dropout(self.conv_module(src)) + if not self.normalize_before: + src = self.norm_conv(src) + + # feed forward module + residual = src + if self.normalize_before: + src = self.norm_ff(src) + src = residual + self.ff_scale * self.dropout(self.feed_forward(src)) + if not self.normalize_before: + src = self.norm_ff(src) + + if self.normalize_before: + src = self.norm_final(src) + + return src + + +class ConformerEncoder(nn.TransformerEncoder): + r"""ConformerEncoder is a stack of N encoder layers + + Args: + encoder_layer: an instance of the ConformerEncoderLayer() class (required). + num_layers: the number of sub-encoder-layers in the encoder (required). + norm: the layer normalization component (optional). + + Examples:: + >>> encoder_layer = ConformerEncoderLayer(d_model=512, nhead=8) + >>> conformer_encoder = ConformerEncoder(encoder_layer, num_layers=6) + >>> src = torch.rand(10, 32, 512) + >>> pos_emb = torch.rand(32, 19, 512) + >>> out = conformer_encoder(src, pos_emb) + """ + + def __init__( + self, encoder_layer: nn.Module, num_layers: int, norm: nn.Module = None + ) -> None: + super(ConformerEncoder, self).__init__( + encoder_layer=encoder_layer, num_layers=num_layers, norm=norm + ) + + def forward( + self, + src: Tensor, + pos_emb: Tensor, + mask: Optional[Tensor] = None, + src_key_padding_mask: Optional[Tensor] = None, + ) -> Tensor: + r"""Pass the input through the encoder layers in turn. + + Args: + src: the sequence to the encoder (required). + pos_emb: Positional embedding tensor (required). + mask: the mask for the src sequence (optional). + src_key_padding_mask: the mask for the src keys per batch (optional). + + Shape: + src: (S, N, E). + pos_emb: (N, 2*S-1, E) + mask: (S, S). + src_key_padding_mask: (N, S). + S is the source sequence length, T is the target sequence length, N is the batch size, E is the feature number + + """ + output = src + + for mod in self.layers: + output = mod( + output, + pos_emb, + src_mask=mask, + src_key_padding_mask=src_key_padding_mask, + ) + + if self.norm is not None: + output = self.norm(output) + + return output + + +class RelPositionalEncoding(torch.nn.Module): + """Relative positional encoding module. + + See : Appendix B in "Transformer-XL: Attentive Language Models Beyond a Fixed-Length Context" + Modified from https://github.com/espnet/espnet/blob/master/espnet/nets/pytorch_backend/transformer/embedding.py + + Args: + d_model: Embedding dimension. + dropout_rate: Dropout rate. + max_len: Maximum input length. + + """ + + def __init__( + self, d_model: int, dropout_rate: float, max_len: int = 5000 + ) -> None: + """Construct an PositionalEncoding object.""" + super(RelPositionalEncoding, self).__init__() + self.d_model = d_model + self.xscale = math.sqrt(self.d_model) + self.dropout = torch.nn.Dropout(p=dropout_rate) + self.pe = None + self.extend_pe(torch.tensor(0.0).expand(1, max_len)) + + def extend_pe(self, x: Tensor) -> None: + """Reset the positional encodings.""" + if self.pe is not None: + # self.pe contains both positive and negative parts + # the length of self.pe is 2 * input_len - 1 + if self.pe.size(1) >= x.size(1) * 2 - 1: + # Note: TorchScript doesn't implement operator== for torch.Device + if self.pe.dtype != x.dtype or str(self.pe.device) != str( + x.device + ): + self.pe = self.pe.to(dtype=x.dtype, device=x.device) + return + # Suppose `i` means to the position of query vecotr and `j` means the + # position of key vector. We use position relative positions when keys + # are to the left (i>j) and negative relative positions otherwise (i Tuple[Tensor, Tensor]: + """Add positional encoding. + + Args: + x (torch.Tensor): Input tensor (batch, time, `*`). + + Returns: + torch.Tensor: Encoded tensor (batch, time, `*`). + torch.Tensor: Encoded tensor (batch, 2*time-1, `*`). + + """ + self.extend_pe(x) + x = x * self.xscale + pos_emb = self.pe[ + :, + self.pe.size(1) // 2 + - x.size(1) + + 1 : self.pe.size(1) // 2 + + x.size(1), + ] + return self.dropout(x), self.dropout(pos_emb) + + +class RelPositionMultiheadAttention(nn.Module): + r"""Multi-Head Attention layer with relative position encoding + + See reference: "Transformer-XL: Attentive Language Models Beyond a Fixed-Length Context" + + Args: + embed_dim: total dimension of the model. + num_heads: parallel attention heads. + dropout: a Dropout layer on attn_output_weights. Default: 0.0. + + Examples:: + + >>> rel_pos_multihead_attn = RelPositionMultiheadAttention(embed_dim, num_heads) + >>> attn_output, attn_output_weights = multihead_attn(query, key, value, pos_emb) + """ + + def __init__( + self, + embed_dim: int, + num_heads: int, + dropout: float = 0.0, + is_espnet_structure: bool = False, + ) -> None: + super(RelPositionMultiheadAttention, self).__init__() + self.embed_dim = embed_dim + self.num_heads = num_heads + self.dropout = dropout + self.head_dim = embed_dim // num_heads + assert ( + self.head_dim * num_heads == self.embed_dim + ), "embed_dim must be divisible by num_heads" + + self.in_proj = nn.Linear(embed_dim, 3 * embed_dim, bias=True) + self.out_proj = nn.Linear(embed_dim, embed_dim, bias=True) + + # linear transformation for positional encoding. + self.linear_pos = nn.Linear(embed_dim, embed_dim, bias=False) + # these two learnable bias are used in matrix c and matrix d + # as described in "Transformer-XL: Attentive Language Models Beyond a Fixed-Length Context" Section 3.3 + self.pos_bias_u = nn.Parameter(torch.Tensor(num_heads, self.head_dim)) + self.pos_bias_v = nn.Parameter(torch.Tensor(num_heads, self.head_dim)) + + self._reset_parameters() + + self.is_espnet_structure = is_espnet_structure + + def _reset_parameters(self) -> None: + nn.init.xavier_uniform_(self.in_proj.weight) + nn.init.constant_(self.in_proj.bias, 0.0) + nn.init.constant_(self.out_proj.bias, 0.0) + + nn.init.xavier_uniform_(self.pos_bias_u) + nn.init.xavier_uniform_(self.pos_bias_v) + + def forward( + self, + query: Tensor, + key: Tensor, + value: Tensor, + pos_emb: Tensor, + key_padding_mask: Optional[Tensor] = None, + need_weights: bool = True, + attn_mask: Optional[Tensor] = None, + ) -> Tuple[Tensor, Optional[Tensor]]: + r""" + Args: + query, key, value: map a query and a set of key-value pairs to an output. + pos_emb: Positional embedding tensor + key_padding_mask: if provided, specified padding elements in the key will + be ignored by the attention. When given a binary mask and a value is True, + the corresponding value on the attention layer will be ignored. When given + a byte mask and a value is non-zero, the corresponding value on the attention + layer will be ignored + need_weights: output attn_output_weights. + attn_mask: 2D or 3D mask that prevents attention to certain positions. A 2D mask will be broadcasted for all + the batches while a 3D mask allows to specify a different mask for the entries of each batch. + + Shape: + - Inputs: + - query: :math:`(L, N, E)` where L is the target sequence length, N is the batch size, E is + the embedding dimension. + - key: :math:`(S, N, E)`, where S is the source sequence length, N is the batch size, E is + the embedding dimension. + - value: :math:`(S, N, E)` where S is the source sequence length, N is the batch size, E is + the embedding dimension. + - pos_emb: :math:`(N, 2*L-1, E)` where L is the target sequence length, N is the batch size, E is + the embedding dimension. + - key_padding_mask: :math:`(N, S)` where N is the batch size, S is the source sequence length. + If a ByteTensor is provided, the non-zero positions will be ignored while the position + with the zero positions will be unchanged. If a BoolTensor is provided, the positions with the + value of ``True`` will be ignored while the position with the value of ``False`` will be unchanged. + - attn_mask: 2D mask :math:`(L, S)` where L is the target sequence length, S is the source sequence length. + 3D mask :math:`(N*num_heads, L, S)` where N is the batch size, L is the target sequence length, + S is the source sequence length. attn_mask ensure that position i is allowed to attend the unmasked + positions. If a ByteTensor is provided, the non-zero positions are not allowed to attend + while the zero positions will be unchanged. If a BoolTensor is provided, positions with ``True`` + is not allowed to attend while ``False`` values will be unchanged. If a FloatTensor + is provided, it will be added to the attention weight. + + - Outputs: + - attn_output: :math:`(L, N, E)` where L is the target sequence length, N is the batch size, + E is the embedding dimension. + - attn_output_weights: :math:`(N, L, S)` where N is the batch size, + L is the target sequence length, S is the source sequence length. + """ + return self.multi_head_attention_forward( + query, + key, + value, + pos_emb, + self.embed_dim, + self.num_heads, + self.in_proj.weight, + self.in_proj.bias, + self.dropout, + self.out_proj.weight, + self.out_proj.bias, + training=self.training, + key_padding_mask=key_padding_mask, + need_weights=need_weights, + attn_mask=attn_mask, + ) + + def rel_shift(self, x: Tensor) -> Tensor: + """Compute relative positional encoding. + + Args: + x: Input tensor (batch, head, time1, 2*time1-1). + time1 means the length of query vector. + + Returns: + Tensor: tensor of shape (batch, head, time1, time2) + (note: time2 has the same value as time1, but it is for + the key, while time1 is for the query). + """ + (batch_size, num_heads, time1, n) = x.shape + assert n == 2 * time1 - 1 + # Note: TorchScript requires explicit arg for stride() + batch_stride = x.stride(0) + head_stride = x.stride(1) + time1_stride = x.stride(2) + n_stride = x.stride(3) + return x.as_strided( + (batch_size, num_heads, time1, time1), + (batch_stride, head_stride, time1_stride - n_stride, n_stride), + storage_offset=n_stride * (time1 - 1), + ) + + def multi_head_attention_forward( + self, + query: Tensor, + key: Tensor, + value: Tensor, + pos_emb: Tensor, + embed_dim_to_check: int, + num_heads: int, + in_proj_weight: Tensor, + in_proj_bias: Tensor, + dropout_p: float, + out_proj_weight: Tensor, + out_proj_bias: Tensor, + training: bool = True, + key_padding_mask: Optional[Tensor] = None, + need_weights: bool = True, + attn_mask: Optional[Tensor] = None, + ) -> Tuple[Tensor, Optional[Tensor]]: + r""" + Args: + query, key, value: map a query and a set of key-value pairs to an output. + pos_emb: Positional embedding tensor + embed_dim_to_check: total dimension of the model. + num_heads: parallel attention heads. + in_proj_weight, in_proj_bias: input projection weight and bias. + dropout_p: probability of an element to be zeroed. + out_proj_weight, out_proj_bias: the output projection weight and bias. + training: apply dropout if is ``True``. + key_padding_mask: if provided, specified padding elements in the key will + be ignored by the attention. This is an binary mask. When the value is True, + the corresponding value on the attention layer will be filled with -inf. + need_weights: output attn_output_weights. + attn_mask: 2D or 3D mask that prevents attention to certain positions. A 2D mask will be broadcasted for all + the batches while a 3D mask allows to specify a different mask for the entries of each batch. + + Shape: + Inputs: + - query: :math:`(L, N, E)` where L is the target sequence length, N is the batch size, E is + the embedding dimension. + - key: :math:`(S, N, E)`, where S is the source sequence length, N is the batch size, E is + the embedding dimension. + - value: :math:`(S, N, E)` where S is the source sequence length, N is the batch size, E is + the embedding dimension. + - pos_emb: :math:`(N, 2*L-1, E)` or :math:`(1, 2*L-1, E)` where L is the target sequence + length, N is the batch size, E is the embedding dimension. + - key_padding_mask: :math:`(N, S)` where N is the batch size, S is the source sequence length. + If a ByteTensor is provided, the non-zero positions will be ignored while the zero positions + will be unchanged. If a BoolTensor is provided, the positions with the + value of ``True`` will be ignored while the position with the value of ``False`` will be unchanged. + - attn_mask: 2D mask :math:`(L, S)` where L is the target sequence length, S is the source sequence length. + 3D mask :math:`(N*num_heads, L, S)` where N is the batch size, L is the target sequence length, + S is the source sequence length. attn_mask ensures that position i is allowed to attend the unmasked + positions. If a ByteTensor is provided, the non-zero positions are not allowed to attend + while the zero positions will be unchanged. If a BoolTensor is provided, positions with ``True`` + are not allowed to attend while ``False`` values will be unchanged. If a FloatTensor + is provided, it will be added to the attention weight. + + Outputs: + - attn_output: :math:`(L, N, E)` where L is the target sequence length, N is the batch size, + E is the embedding dimension. + - attn_output_weights: :math:`(N, L, S)` where N is the batch size, + L is the target sequence length, S is the source sequence length. + """ + + tgt_len, bsz, embed_dim = query.size() + assert embed_dim == embed_dim_to_check + assert key.size(0) == value.size(0) and key.size(1) == value.size(1) + + head_dim = embed_dim // num_heads + assert ( + head_dim * num_heads == embed_dim + ), "embed_dim must be divisible by num_heads" + scaling = float(head_dim) ** -0.5 + + if torch.equal(query, key) and torch.equal(key, value): + # self-attention + q, k, v = nn.functional.linear( + query, in_proj_weight, in_proj_bias + ).chunk(3, dim=-1) + + elif torch.equal(key, value): + # encoder-decoder attention + # This is inline in_proj function with in_proj_weight and in_proj_bias + _b = in_proj_bias + _start = 0 + _end = embed_dim + _w = in_proj_weight[_start:_end, :] + if _b is not None: + _b = _b[_start:_end] + q = nn.functional.linear(query, _w, _b) + # This is inline in_proj function with in_proj_weight and in_proj_bias + _b = in_proj_bias + _start = embed_dim + _end = None + _w = in_proj_weight[_start:, :] + if _b is not None: + _b = _b[_start:] + k, v = nn.functional.linear(key, _w, _b).chunk(2, dim=-1) + + else: + # This is inline in_proj function with in_proj_weight and in_proj_bias + _b = in_proj_bias + _start = 0 + _end = embed_dim + _w = in_proj_weight[_start:_end, :] + if _b is not None: + _b = _b[_start:_end] + q = nn.functional.linear(query, _w, _b) + + # This is inline in_proj function with in_proj_weight and in_proj_bias + _b = in_proj_bias + _start = embed_dim + _end = embed_dim * 2 + _w = in_proj_weight[_start:_end, :] + if _b is not None: + _b = _b[_start:_end] + k = nn.functional.linear(key, _w, _b) + + # This is inline in_proj function with in_proj_weight and in_proj_bias + _b = in_proj_bias + _start = embed_dim * 2 + _end = None + _w = in_proj_weight[_start:, :] + if _b is not None: + _b = _b[_start:] + v = nn.functional.linear(value, _w, _b) + + if not self.is_espnet_structure: + q = q * scaling + + if attn_mask is not None: + assert ( + attn_mask.dtype == torch.float32 + or attn_mask.dtype == torch.float64 + or attn_mask.dtype == torch.float16 + or attn_mask.dtype == torch.uint8 + or attn_mask.dtype == torch.bool + ), "Only float, byte, and bool types are supported for attn_mask, not {}".format( + attn_mask.dtype + ) + if attn_mask.dtype == torch.uint8: + warnings.warn( + "Byte tensor for attn_mask is deprecated. Use bool tensor instead." + ) + attn_mask = attn_mask.to(torch.bool) + + if attn_mask.dim() == 2: + attn_mask = attn_mask.unsqueeze(0) + if list(attn_mask.size()) != [1, query.size(0), key.size(0)]: + raise RuntimeError( + "The size of the 2D attn_mask is not correct." + ) + elif attn_mask.dim() == 3: + if list(attn_mask.size()) != [ + bsz * num_heads, + query.size(0), + key.size(0), + ]: + raise RuntimeError( + "The size of the 3D attn_mask is not correct." + ) + else: + raise RuntimeError( + "attn_mask's dimension {} is not supported".format( + attn_mask.dim() + ) + ) + # attn_mask's dim is 3 now. + + # convert ByteTensor key_padding_mask to bool + if ( + key_padding_mask is not None + and key_padding_mask.dtype == torch.uint8 + ): + warnings.warn( + "Byte tensor for key_padding_mask is deprecated. Use bool tensor instead." + ) + key_padding_mask = key_padding_mask.to(torch.bool) + + q = q.contiguous().view(tgt_len, bsz, num_heads, head_dim) + k = k.contiguous().view(-1, bsz, num_heads, head_dim) + v = v.contiguous().view(-1, bsz * num_heads, head_dim).transpose(0, 1) + + src_len = k.size(0) + + if key_padding_mask is not None: + assert key_padding_mask.size(0) == bsz, "{} == {}".format( + key_padding_mask.size(0), bsz + ) + assert key_padding_mask.size(1) == src_len, "{} == {}".format( + key_padding_mask.size(1), src_len + ) + + q = q.transpose(0, 1) # (batch, time1, head, d_k) + + pos_emb_bsz = pos_emb.size(0) + assert pos_emb_bsz in (1, bsz) # actually it is 1 + p = self.linear_pos(pos_emb).view(pos_emb_bsz, -1, num_heads, head_dim) + p = p.transpose(1, 2) # (batch, head, 2*time1-1, 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 + ) # (batch, head, time1, d_k) + + # compute attention score + # first compute matrix a and matrix c + # as described in "Transformer-XL: Attentive Language Models Beyond a Fixed-Length Context" Section 3.3 + k = k.permute(1, 2, 3, 0) # (batch, head, d_k, time2) + matrix_ac = torch.matmul( + q_with_bias_u, k + ) # (batch, head, time1, time2) + + # compute matrix b and matrix d + matrix_bd = torch.matmul( + q_with_bias_v, p.transpose(-2, -1) + ) # (batch, head, time1, 2*time1-1) + matrix_bd = self.rel_shift(matrix_bd) + + if not self.is_espnet_structure: + attn_output_weights = ( + matrix_ac + matrix_bd + ) # (batch, head, time1, time2) + else: + attn_output_weights = ( + matrix_ac + matrix_bd + ) * scaling # (batch, head, time1, time2) + + attn_output_weights = attn_output_weights.view( + bsz * num_heads, tgt_len, -1 + ) + + assert list(attn_output_weights.size()) == [ + bsz * num_heads, + tgt_len, + src_len, + ] + + if attn_mask is not None: + if attn_mask.dtype == torch.bool: + attn_output_weights.masked_fill_(attn_mask, float("-inf")) + else: + attn_output_weights += attn_mask + + if key_padding_mask is not None: + attn_output_weights = attn_output_weights.view( + bsz, num_heads, tgt_len, src_len + ) + attn_output_weights = attn_output_weights.masked_fill( + key_padding_mask.unsqueeze(1).unsqueeze(2), + float("-inf"), + ) + attn_output_weights = attn_output_weights.view( + bsz * num_heads, tgt_len, src_len + ) + + attn_output_weights = nn.functional.softmax(attn_output_weights, dim=-1) + attn_output_weights = nn.functional.dropout( + attn_output_weights, p=dropout_p, training=training + ) + + attn_output = torch.bmm(attn_output_weights, v) + assert list(attn_output.size()) == [bsz * num_heads, tgt_len, head_dim] + attn_output = ( + attn_output.transpose(0, 1) + .contiguous() + .view(tgt_len, bsz, embed_dim) + ) + attn_output = nn.functional.linear( + attn_output, out_proj_weight, out_proj_bias + ) + + if need_weights: + # average attention weights over heads + attn_output_weights = attn_output_weights.view( + bsz, num_heads, tgt_len, src_len + ) + return attn_output, attn_output_weights.sum(dim=1) / num_heads + else: + return attn_output, None + + +class ConvolutionModule(nn.Module): + """ConvolutionModule in Conformer model. + Modified from https://github.com/espnet/espnet/blob/master/espnet/nets/pytorch_backend/conformer/convolution.py + + Args: + channels (int): The number of channels of conv layers. + kernel_size (int): Kernerl size of conv layers. + bias (bool): Whether to use bias in conv layers (default=True). + + """ + + def __init__( + self, channels: int, kernel_size: int, bias: bool = True + ) -> None: + """Construct an ConvolutionModule object.""" + super(ConvolutionModule, self).__init__() + # kernerl_size should be a odd number for 'SAME' padding + assert (kernel_size - 1) % 2 == 0 + + self.pointwise_conv1 = nn.Conv1d( + channels, + 2 * channels, + kernel_size=1, + stride=1, + padding=0, + bias=bias, + ) + self.depthwise_conv = nn.Conv1d( + channels, + channels, + kernel_size, + stride=1, + padding=(kernel_size - 1) // 2, + groups=channels, + bias=bias, + ) + self.norm = nn.BatchNorm1d(channels) + self.pointwise_conv2 = nn.Conv1d( + channels, + channels, + kernel_size=1, + stride=1, + padding=0, + bias=bias, + ) + self.activation = Swish() + + def forward(self, x: Tensor) -> Tensor: + """Compute convolution module. + + Args: + x: Input tensor (#time, batch, channels). + + Returns: + Tensor: Output tensor (#time, batch, channels). + + """ + # exchange the temporal dimension and the feature dimension + x = x.permute(1, 2, 0) # (#batch, channels, time). + + # GLU mechanism + x = self.pointwise_conv1(x) # (batch, 2*channels, time) + x = nn.functional.glu(x, dim=1) # (batch, channels, time) + + # 1D Depthwise Conv + x = self.depthwise_conv(x) + x = self.activation(self.norm(x)) + + x = self.pointwise_conv2(x) # (batch, channel, time) + + return x.permute(2, 0, 1) + + +class Swish(torch.nn.Module): + """Construct an Swish object.""" + + def forward(self, x: Tensor) -> Tensor: + """Return Swich activation function.""" + return x * torch.sigmoid(x) + + +def identity(x): + return x diff --git a/egs/librispeech/ASR/conformer_ctc_embedding_scale/decode.py b/egs/librispeech/ASR/conformer_ctc_embedding_scale/decode.py new file mode 100755 index 000000000..c3354c0a3 --- /dev/null +++ b/egs/librispeech/ASR/conformer_ctc_embedding_scale/decode.py @@ -0,0 +1,548 @@ +#!/usr/bin/env python3 + +# Copyright 2021 Xiaomi Corporation (Author: Liyong Guo, Fangjun Kuang) + +# (still working in progress) + +import argparse +import logging +from collections import defaultdict +from pathlib import Path +from typing import Dict, List, Optional, Tuple + +import k2 +import torch +import torch.nn as nn +from asr_datamodule import LibriSpeechAsrDataModule +from conformer import Conformer + +from icefall.bpe_graph_compiler import BpeCtcTrainingGraphCompiler +from icefall.checkpoint import average_checkpoints, load_checkpoint +from icefall.decode import ( + get_lattice, + nbest_decoding, + nbest_oracle, + one_best_decoding, + rescore_with_attention_decoder, + rescore_with_n_best_list, + rescore_with_whole_lattice, +) +from icefall.lexicon import Lexicon +from icefall.utils import ( + AttributeDict, + get_texts, + setup_logger, + store_transcripts, + write_error_stats, +) + + +def get_parser(): + parser = argparse.ArgumentParser( + formatter_class=argparse.ArgumentDefaultsHelpFormatter + ) + + parser.add_argument( + "--epoch", + type=int, + default=9, + help="It specifies the checkpoint to use for decoding." + "Note: Epoch counts from 0.", + ) + parser.add_argument( + "--avg", + type=int, + default=1, + help="Number of checkpoints to average. Automatically select " + "consecutive checkpoints before the checkpoint specified by " + "'--epoch'. ", + ) + + parser.add_argument( + "--lattice-score-scale", + type=float, + default=1.0, + help="The scale to be applied to `lattice.scores`." + "It's needed if you use any kinds of n-best based rescoring. " + "Currently, it is used when the decoding method is: nbest, " + "nbest-rescoring, attention-decoder, and nbest-oracle. " + "A smaller value results in more unique paths.", + ) + + return parser + + +def get_params() -> AttributeDict: + params = AttributeDict( + { + "exp_dir": Path("conformer_ctc_embedding_scale/exp"), + "lang_dir": Path("data/lang_bpe"), + "lm_dir": Path("data/lm"), + "feature_dim": 80, + "nhead": 8, + "attention_dim": 512, + "subsampling_factor": 4, + "num_decoder_layers": 6, + "vgg_frontend": False, + "is_espnet_structure": True, + "mmi_loss": False, + "use_feat_batchnorm": True, + "search_beam": 20, + "output_beam": 8, + "min_active_states": 30, + "max_active_states": 10000, + "use_double_scores": True, + # Possible values for method: + # - 1best + # - nbest + # - nbest-rescoring + # - whole-lattice-rescoring + # - attention-decoder + # - nbest-oracle + # "method": "nbest", + # "method": "nbest-rescoring", + # "method": "whole-lattice-rescoring", + "method": "attention-decoder", + # "method": "nbest-oracle", + # num_paths is used when method is "nbest", "nbest-rescoring", + # attention-decoder, and nbest-oracle + "num_paths": 100, + } + ) + return params + + +def decode_one_batch( + params: AttributeDict, + model: nn.Module, + HLG: k2.Fsa, + batch: dict, + lexicon: Lexicon, + sos_id: int, + eos_id: int, + G: Optional[k2.Fsa] = None, +) -> Dict[str, List[List[int]]]: + """Decode one batch and return the result in a dict. The dict has the + following format: + + - key: It indicates the setting used for decoding. For example, + if no rescoring is used, the key is the string `no_rescore`. + If LM rescoring is used, the key is the string `lm_scale_xxx`, + where `xxx` is the value of `lm_scale`. An example key is + `lm_scale_0.7` + - value: It contains the decoding result. `len(value)` equals to + batch size. `value[i]` is the decoding result for the i-th + utterance in the given batch. + Args: + params: + It's the return value of :func:`get_params`. + + - params.method is "1best", it uses 1best decoding without LM rescoring. + - params.method is "nbest", it uses nbest decoding without LM rescoring. + - params.method is "nbest-rescoring", it uses nbest LM rescoring. + - params.method is "whole-lattice-rescoring", it uses whole lattice LM + rescoring. + + model: + The neural model. + HLG: + The decoding graph. + batch: + It is the return value from iterating + `lhotse.dataset.K2SpeechRecognitionDataset`. See its documentation + for the format of the `batch`. + lexicon: + It contains word symbol table. + sos_id: + The token ID of the SOS. + eos_id: + The token ID of the EOS. + G: + An LM. It is not None when params.method is "nbest-rescoring" + or "whole-lattice-rescoring". In general, the G in HLG + is a 3-gram LM, while this G is a 4-gram LM. + Returns: + Return the decoding result. See above description for the format of + the returned dict. + """ + device = HLG.device + feature = batch["inputs"] + assert feature.ndim == 3 + feature = feature.to(device) + # at entry, feature is [N, T, C] + + supervisions = batch["supervisions"] + + nnet_output, memory, memory_key_padding_mask = model(feature, supervisions) + # nnet_output is [N, T, C] + + supervision_segments = torch.stack( + ( + supervisions["sequence_idx"], + supervisions["start_frame"] // params.subsampling_factor, + supervisions["num_frames"] // params.subsampling_factor, + ), + 1, + ).to(torch.int32) + + lattice = get_lattice( + nnet_output=nnet_output, + HLG=HLG, + supervision_segments=supervision_segments, + search_beam=params.search_beam, + output_beam=params.output_beam, + min_active_states=params.min_active_states, + max_active_states=params.max_active_states, + subsampling_factor=params.subsampling_factor, + ) + + if params.method == "nbest-oracle": + # Note: You can also pass rescored lattices to it. + # We choose the HLG decoded lattice for speed reasons + # as HLG decoding is faster and the oracle WER + # is slightly worse than that of rescored lattices. + return nbest_oracle( + lattice=lattice, + num_paths=params.num_paths, + ref_texts=supervisions["text"], + lexicon=lexicon, + scale=params.lattice_score_scale, + ) + + if params.method in ["1best", "nbest"]: + if params.method == "1best": + best_path = one_best_decoding( + lattice=lattice, use_double_scores=params.use_double_scores + ) + key = "no_rescore" + else: + best_path = nbest_decoding( + lattice=lattice, + num_paths=params.num_paths, + use_double_scores=params.use_double_scores, + scale=params.lattice_score_scale, + ) + key = f"no_rescore-scale-{params.lattice_score_scale}-{params.num_paths}" # noqa + + hyps = get_texts(best_path) + hyps = [[lexicon.word_table[i] for i in ids] for ids in hyps] + return {key: hyps} + + assert params.method in [ + "nbest-rescoring", + "whole-lattice-rescoring", + "attention-decoder", + ] + + lm_scale_list = [0.8, 0.9, 1.0, 1.1, 1.2, 1.3] + lm_scale_list += [1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0] + + if params.method == "nbest-rescoring": + best_path_dict = rescore_with_n_best_list( + lattice=lattice, + G=G, + num_paths=params.num_paths, + lm_scale_list=lm_scale_list, + scale=params.lattice_score_scale, + ) + elif params.method == "whole-lattice-rescoring": + best_path_dict = rescore_with_whole_lattice( + lattice=lattice, G_with_epsilon_loops=G, lm_scale_list=lm_scale_list + ) + elif params.method == "attention-decoder": + # lattice uses a 3-gram Lm. We rescore it with a 4-gram LM. + rescored_lattice = rescore_with_whole_lattice( + lattice=lattice, G_with_epsilon_loops=G, lm_scale_list=None + ) + + best_path_dict = rescore_with_attention_decoder( + lattice=rescored_lattice, + num_paths=params.num_paths, + model=model, + memory=memory, + memory_key_padding_mask=memory_key_padding_mask, + sos_id=sos_id, + eos_id=eos_id, + scale=params.lattice_score_scale, + ) + else: + assert False, f"Unsupported decoding method: {params.method}" + + ans = dict() + for lm_scale_str, best_path in best_path_dict.items(): + hyps = get_texts(best_path) + hyps = [[lexicon.word_table[i] for i in ids] for ids in hyps] + ans[lm_scale_str] = hyps + return ans + + +def decode_dataset( + dl: torch.utils.data.DataLoader, + params: AttributeDict, + model: nn.Module, + HLG: k2.Fsa, + lexicon: Lexicon, + sos_id: int, + eos_id: int, + G: Optional[k2.Fsa] = None, +) -> Dict[str, List[Tuple[List[int], List[int]]]]: + """Decode dataset. + + Args: + dl: + PyTorch's dataloader containing the dataset to decode. + params: + It is returned by :func:`get_params`. + model: + The neural model. + HLG: + The decoding graph. + lexicon: + It contains word symbol table. + sos_id: + The token ID for SOS. + eos_id: + The token ID for EOS. + G: + An LM. It is not None when params.method is "nbest-rescoring" + or "whole-lattice-rescoring". In general, the G in HLG + is a 3-gram LM, while this G is a 4-gram LM. + Returns: + Return a dict, whose key may be "no-rescore" if no LM rescoring + is used, or it may be "lm_scale_0.7" if LM rescoring is used. + Its value is a list of tuples. Each tuple contains two elements: + The first is the reference transcript, and the second is the + predicted result. + """ + results = [] + + num_cuts = 0 + + try: + num_batches = len(dl) + except TypeError: + num_batches = "?" + + results = defaultdict(list) + for batch_idx, batch in enumerate(dl): + texts = batch["supervisions"]["text"] + + hyps_dict = decode_one_batch( + params=params, + model=model, + HLG=HLG, + batch=batch, + lexicon=lexicon, + G=G, + sos_id=sos_id, + eos_id=eos_id, + ) + + for lm_scale, hyps in hyps_dict.items(): + this_batch = [] + assert len(hyps) == len(texts) + for hyp_words, ref_text in zip(hyps, texts): + ref_words = ref_text.split() + this_batch.append((ref_words, hyp_words)) + + results[lm_scale].extend(this_batch) + + num_cuts += len(batch["supervisions"]["text"]) + + if batch_idx % 100 == 0: + batch_str = f"{batch_idx}/{num_batches}" + + logging.info( + f"batch {batch_str}, cuts processed until now is {num_cuts}" + ) + return results + + +def save_results( + params: AttributeDict, + test_set_name: str, + results_dict: Dict[str, List[Tuple[List[int], List[int]]]], +): + if params.method == "attention-decoder": + # Set it to False since there are too many logs. + enable_log = False + else: + enable_log = True + test_set_wers = dict() + for key, results in results_dict.items(): + recog_path = params.exp_dir / f"recogs-{test_set_name}-{key}.txt" + store_transcripts(filename=recog_path, texts=results) + if enable_log: + logging.info(f"The transcripts are stored in {recog_path}") + + # The following prints out WERs, per-word error statistics and aligned + # ref/hyp pairs. + errs_filename = params.exp_dir / f"errs-{test_set_name}-{key}.txt" + with open(errs_filename, "w") as f: + wer = write_error_stats( + f, f"{test_set_name}-{key}", results, enable_log=enable_log + ) + test_set_wers[key] = wer + + if enable_log: + logging.info( + "Wrote detailed error stats to {}".format(errs_filename) + ) + + test_set_wers = sorted(test_set_wers.items(), key=lambda x: x[1]) + errs_info = params.exp_dir / f"wer-summary-{test_set_name}.txt" + with open(errs_info, "w") as f: + print("settings\tWER", file=f) + for key, val in test_set_wers: + print("{}\t{}".format(key, val), file=f) + + s = "\nFor {}, WER of different settings are:\n".format(test_set_name) + note = "\tbest for {}".format(test_set_name) + for key, val in test_set_wers: + s += "{}\t{}{}\n".format(key, val, note) + note = "" + logging.info(s) + + +@torch.no_grad() +def main(): + parser = get_parser() + LibriSpeechAsrDataModule.add_arguments(parser) + args = parser.parse_args() + + params = get_params() + params.update(vars(args)) + + setup_logger(f"{params.exp_dir}/log-{params.method}/log-decode") + logging.info("Decoding started") + logging.info(params) + + lexicon = Lexicon(params.lang_dir) + max_token_id = max(lexicon.tokens) + num_classes = max_token_id + 1 # +1 for the blank + + device = torch.device("cpu") + if torch.cuda.is_available(): + device = torch.device("cuda", 0) + + logging.info(f"device: {device}") + + graph_compiler = BpeCtcTrainingGraphCompiler( + params.lang_dir, + device=device, + sos_token="", + eos_token="", + ) + sos_id = graph_compiler.sos_id + eos_id = graph_compiler.eos_id + + HLG = k2.Fsa.from_dict( + torch.load(f"{params.lang_dir}/HLG.pt", map_location="cpu") + ) + HLG = HLG.to(device) + assert HLG.requires_grad is False + + if not hasattr(HLG, "lm_scores"): + HLG.lm_scores = HLG.scores.clone() + + if params.method in ( + "nbest-rescoring", + "whole-lattice-rescoring", + "attention-decoder", + ): + if not (params.lm_dir / "G_4_gram.pt").is_file(): + logging.info("Loading G_4_gram.fst.txt") + logging.warning("It may take 8 minutes.") + with open(params.lm_dir / "G_4_gram.fst.txt") as f: + first_word_disambig_id = lexicon.word_table["#0"] + + G = k2.Fsa.from_openfst(f.read(), acceptor=False) + # G.aux_labels is not needed in later computations, so + # remove it here. + del G.aux_labels + # CAUTION: The following line is crucial. + # Arcs entering the back-off state have label equal to #0. + # We have to change it to 0 here. + G.labels[G.labels >= first_word_disambig_id] = 0 + G = k2.Fsa.from_fsas([G]).to(device) + G = k2.arc_sort(G) + torch.save(G.as_dict(), params.lm_dir / "G_4_gram.pt") + else: + logging.info("Loading pre-compiled G_4_gram.pt") + d = torch.load(params.lm_dir / "G_4_gram.pt", map_location="cpu") + G = k2.Fsa.from_dict(d).to(device) + + if params.method in ["whole-lattice-rescoring", "attention-decoder"]: + # Add epsilon self-loops to G as we will compose + # it with the whole lattice later + G = k2.add_epsilon_self_loops(G) + G = k2.arc_sort(G) + G = G.to(device) + + # G.lm_scores is used to replace HLG.lm_scores during + # LM rescoring. + G.lm_scores = G.scores.clone() + else: + G = None + + model = Conformer( + num_features=params.feature_dim, + nhead=params.nhead, + d_model=params.attention_dim, + num_classes=num_classes, + subsampling_factor=params.subsampling_factor, + num_decoder_layers=params.num_decoder_layers, + vgg_frontend=params.vgg_frontend, + is_espnet_structure=params.is_espnet_structure, + mmi_loss=params.mmi_loss, + use_feat_batchnorm=params.use_feat_batchnorm, + ) + + if params.avg == 1: + load_checkpoint(f"{params.exp_dir}/epoch-{params.epoch}.pt", model) + else: + start = params.epoch - params.avg + 1 + filenames = [] + for i in range(start, params.epoch + 1): + if start >= 0: + filenames.append(f"{params.exp_dir}/epoch-{i}.pt") + logging.info(f"averaging {filenames}") + model.load_state_dict(average_checkpoints(filenames)) + + model.to(device) + model.eval() + num_param = sum([p.numel() for p in model.parameters()]) + logging.info(f"Number of model parameters: {num_param}") + + librispeech = LibriSpeechAsrDataModule(args) + # CAUTION: `test_sets` is for displaying only. + # If you want to skip test-clean, you have to skip + # it inside the for loop. That is, use + # + # if test_set == 'test-clean': continue + # + test_sets = ["test-clean", "test-other"] + for test_set, test_dl in zip(test_sets, librispeech.test_dataloaders()): + results_dict = decode_dataset( + dl=test_dl, + params=params, + model=model, + HLG=HLG, + lexicon=lexicon, + G=G, + sos_id=sos_id, + eos_id=eos_id, + ) + + save_results( + params=params, test_set_name=test_set, results_dict=results_dict + ) + + logging.info("Done!") + + +torch.set_num_threads(1) +torch.set_num_interop_threads(1) + +if __name__ == "__main__": + main() diff --git a/egs/librispeech/ASR/conformer_ctc_embedding_scale/embedding.py b/egs/librispeech/ASR/conformer_ctc_embedding_scale/embedding.py new file mode 100644 index 000000000..72f9ed53f --- /dev/null +++ b/egs/librispeech/ASR/conformer_ctc_embedding_scale/embedding.py @@ -0,0 +1,221 @@ + +# This file is copied & modified from pytorch/torch/nn/modules/sparse.py +# It modifies nn.Embedding +import math +from typing import Optional + +import torch +import torch.nn as nn +import torch.nn.functional as F +from torch import Tensor +from torch.nn import Parameter + + +class Embedding(nn.Module): + r"""A simple lookup table that stores embeddings of a fixed dictionary and size. + + This module is often used to store word embeddings and retrieve them using indices. + The input to the module is a list of indices, and the output is the corresponding + word embeddings. + + Args: + num_embeddings (int): size of the dictionary of embeddings + embedding_dim (int): the size of each embedding vector + padding_idx (int, optional): If specified, the entries at :attr:`padding_idx` do not contribute to the gradient; + therefore, the embedding vector at :attr:`padding_idx` is not updated during training, + i.e. it remains as a fixed "pad". For a newly constructed Embedding, + the embedding vector at :attr:`padding_idx` will default to all zeros, + but can be updated to another value to be used as the padding vector. + max_norm (float, optional): If given, each embedding vector with norm larger than :attr:`max_norm` + is renormalized to have norm :attr:`max_norm`. + norm_type (float, optional): The p of the p-norm to compute for the :attr:`max_norm` option. Default ``2``. + scale_grad_by_freq (boolean, optional): If given, this will scale gradients by the inverse of frequency of + the words in the mini-batch. Default ``False``. + sparse (bool, optional): If ``True``, gradient w.r.t. :attr:`weight` matrix will be a sparse tensor. + See Notes for more details regarding sparse gradients. + + Attributes: + weight (Tensor): the learnable weights of the module of shape (num_embeddings, embedding_dim) + initialized from :math:`\mathcal{N}(0, 1)` + + Shape: + - Input: :math:`(*)`, IntTensor or LongTensor of arbitrary shape containing the indices to extract + - Output: :math:`(*, H)`, where `*` is the input shape and :math:`H=\text{embedding\_dim}` + + .. note:: + Keep in mind that only a limited number of optimizers support + sparse gradients: currently it's :class:`optim.SGD` (`CUDA` and `CPU`), + :class:`optim.SparseAdam` (`CUDA` and `CPU`) and :class:`optim.Adagrad` (`CPU`) + + .. note:: + When :attr:`max_norm` is not ``None``, :class:`Embedding`'s forward method will modify the + :attr:`weight` tensor in-place. Since tensors needed for gradient computations cannot be + modified in-place, performing a differentiable operation on ``Embedding.weight`` before + calling :class:`Embedding`'s forward method requires cloning ``Embedding.weight`` when + :attr:`max_norm` is not ``None``. For example:: + + n, d, m = 3, 5, 7 + embedding = nn.Embedding(n, d, max_norm=True) + W = torch.randn((m, d), requires_grad=True) + idx = torch.tensor([1, 2]) + a = embedding.weight.clone() @ W.t() # weight must be cloned for this to be differentiable + b = embedding(idx) @ W.t() # modifies weight in-place + out = (a.unsqueeze(0) + b.unsqueeze(1)) + loss = out.sigmoid().prod() + loss.backward() + + Examples:: + + >>> # an Embedding module containing 10 tensors of size 3 + >>> embedding = nn.Embedding(10, 3) + >>> # a batch of 2 samples of 4 indices each + >>> input = torch.LongTensor([[1,2,4,5],[4,3,2,9]]) + >>> embedding(input) + tensor([[[-0.0251, -1.6902, 0.7172], + [-0.6431, 0.0748, 0.6969], + [ 1.4970, 1.3448, -0.9685], + [-0.3677, -2.7265, -0.1685]], + + [[ 1.4970, 1.3448, -0.9685], + [ 0.4362, -0.4004, 0.9400], + [-0.6431, 0.0748, 0.6969], + [ 0.9124, -2.3616, 1.1151]]]) + + + >>> # example with padding_idx + >>> embedding = nn.Embedding(10, 3, padding_idx=0) + >>> input = torch.LongTensor([[0,2,0,5]]) + >>> embedding(input) + tensor([[[ 0.0000, 0.0000, 0.0000], + [ 0.1535, -2.0309, 0.9315], + [ 0.0000, 0.0000, 0.0000], + [-0.1655, 0.9897, 0.0635]]]) + + >>> # example of changing `pad` vector + >>> padding_idx = 0 + >>> embedding = nn.Embedding(3, 3, padding_idx=padding_idx) + >>> embedding.weight + Parameter containing: + tensor([[ 0.0000, 0.0000, 0.0000], + [-0.7895, -0.7089, -0.0364], + [ 0.6778, 0.5803, 0.2678]], requires_grad=True) + >>> with torch.no_grad(): + ... embedding.weight[padding_idx] = torch.ones(3) + >>> embedding.weight + Parameter containing: + tensor([[ 1.0000, 1.0000, 1.0000], + [-0.7895, -0.7089, -0.0364], + [ 0.6778, 0.5803, 0.2678]], requires_grad=True) + """ + __constants__ = ['num_embeddings', 'embedding_dim', 'padding_idx', 'max_norm', + 'norm_type', 'scale_grad_by_freq', 'sparse'] + + num_embeddings: int + embedding_dim: int + padding_idx: Optional[int] + max_norm: Optional[float] + norm_type: float + scale_grad_by_freq: bool + weight: Tensor + sparse: bool + + def __init__(self, num_embeddings: int, embedding_dim: int, padding_idx: Optional[int] = None, + max_norm: Optional[float] = None, norm_type: float = 2., scale_grad_by_freq: bool = False, + sparse: bool = False, _weight: Optional[Tensor] = None) -> None: + super(Embedding, self).__init__() + self.num_embeddings = num_embeddings + self.embedding_dim = embedding_dim + if padding_idx is not None: + if padding_idx > 0: + assert padding_idx < self.num_embeddings, 'Padding_idx must be within num_embeddings' + elif padding_idx < 0: + assert padding_idx >= -self.num_embeddings, 'Padding_idx must be within num_embeddings' + padding_idx = self.num_embeddings + padding_idx + self.padding_idx = padding_idx + self.max_norm = max_norm + self.norm_type = norm_type + self.scale_grad_by_freq = scale_grad_by_freq + self.embedding_scale = math.sqrt(self.embedding_dim) + if _weight is None: + self.weight = Parameter(torch.empty(num_embeddings, embedding_dim)) + self.reset_parameters() + else: + assert list(_weight.shape) == [num_embeddings, embedding_dim], \ + 'Shape of weight does not match num_embeddings and embedding_dim' + self.weight = Parameter(_weight) + + self.sparse = sparse + + def reset_parameters(self) -> None: + std = 1 / self.embedding_scale + nn.init.normal_(self.weight, std=std) + self._fill_padding_idx_with_zero() + + def _fill_padding_idx_with_zero(self) -> None: + if self.padding_idx is not None: + with torch.no_grad(): + self.weight[self.padding_idx].fill_(0) + + def forward(self, input: Tensor) -> Tensor: + return F.embedding( + input, self.weight, self.padding_idx, self.max_norm, + self.norm_type, self.scale_grad_by_freq, self.sparse) * self.embedding_scale + + def extra_repr(self) -> str: + s = '{num_embeddings}, {embedding_dim}' + if self.padding_idx is not None: + s += ', padding_idx={padding_idx}' + if self.max_norm is not None: + s += ', max_norm={max_norm}' + if self.norm_type != 2: + s += ', norm_type={norm_type}' + if self.scale_grad_by_freq is not False: + s += ', scale_grad_by_freq={scale_grad_by_freq}' + if self.sparse is not False: + s += ', sparse=True' + return s.format(**self.__dict__) + + @classmethod + def from_pretrained(cls, embeddings, freeze=True, padding_idx=None, + max_norm=None, norm_type=2., scale_grad_by_freq=False, + sparse=False): + r"""Creates Embedding instance from given 2-dimensional FloatTensor. + + Args: + embeddings (Tensor): FloatTensor containing weights for the Embedding. + First dimension is being passed to Embedding as ``num_embeddings``, second as ``embedding_dim``. + freeze (boolean, optional): If ``True``, the tensor does not get updated in the learning process. + Equivalent to ``embedding.weight.requires_grad = False``. Default: ``True`` + padding_idx (int, optional): If specified, the entries at :attr:`padding_idx` do not contribute to the gradient; + therefore, the embedding vector at :attr:`padding_idx` is not updated during training, + i.e. it remains as a fixed "pad". + max_norm (float, optional): See module initialization documentation. + norm_type (float, optional): See module initialization documentation. Default ``2``. + scale_grad_by_freq (boolean, optional): See module initialization documentation. Default ``False``. + sparse (bool, optional): See module initialization documentation. + + Examples:: + + >>> # FloatTensor containing pretrained weights + >>> weight = torch.FloatTensor([[1, 2.3, 3], [4, 5.1, 6.3]]) + >>> embedding = nn.Embedding.from_pretrained(weight) + >>> # Get embeddings for index 1 + >>> input = torch.LongTensor([1]) + >>> embedding(input) + tensor([[ 4.0000, 5.1000, 6.3000]]) + """ + assert embeddings.dim() == 2, \ + 'Embeddings parameter is expected to be 2-dimensional' + rows, cols = embeddings.shape + embedding = cls( + num_embeddings=rows, + embedding_dim=cols, + _weight=embeddings, + padding_idx=padding_idx, + max_norm=max_norm, + norm_type=norm_type, + scale_grad_by_freq=scale_grad_by_freq, + sparse=sparse) + embedding.weight.requires_grad = not freeze + return embedding + diff --git a/egs/librispeech/ASR/conformer_ctc_embedding_scale/pretrained.py b/egs/librispeech/ASR/conformer_ctc_embedding_scale/pretrained.py new file mode 100755 index 000000000..c63616d28 --- /dev/null +++ b/egs/librispeech/ASR/conformer_ctc_embedding_scale/pretrained.py @@ -0,0 +1,350 @@ +#!/usr/bin/env python3 + +import argparse +import logging +import math +from typing import List + +import k2 +import kaldifeat +import torch +import torchaudio +from conformer import Conformer +from torch.nn.utils.rnn import pad_sequence + +from icefall.decode import ( + get_lattice, + one_best_decoding, + rescore_with_attention_decoder, + rescore_with_whole_lattice, +) +from icefall.utils import AttributeDict, get_texts + + +def get_parser(): + parser = argparse.ArgumentParser( + formatter_class=argparse.ArgumentDefaultsHelpFormatter + ) + + parser.add_argument( + "--checkpoint", + type=str, + required=True, + help="Path to the checkpoint. " + "The checkpoint is assumed to be saved by " + "icefall.checkpoint.save_checkpoint().", + ) + + parser.add_argument( + "--words-file", + type=str, + required=True, + help="Path to words.txt", + ) + + parser.add_argument( + "--HLG", type=str, required=True, help="Path to HLG.pt." + ) + + parser.add_argument( + "--method", + type=str, + default="1best", + help="""Decoding method. + Possible values are: + (1) 1best - Use the best path as decoding output. Only + the transformer encoder output is used for decoding. + We call it HLG decoding. + (2) whole-lattice-rescoring - Use an LM to rescore the + decoding lattice and then use 1best to decode the + rescored lattice. + We call it HLG decoding + n-gram LM rescoring. + (3) attention-decoder - Extract n paths from he rescored + lattice and use the transformer attention decoder for + rescoring. + We call it HLG decoding + n-gram LM rescoring + attention + decoder rescoring. + """, + ) + + parser.add_argument( + "--G", + type=str, + help="""An LM for rescoring. + Used only when method is + whole-lattice-rescoring or attention-decoder. + It's usually a 4-gram LM. + """, + ) + + parser.add_argument( + "--num-paths", + type=int, + default=100, + help=""" + Used only when method is attention-decoder. + It specifies the size of n-best list.""", + ) + + parser.add_argument( + "--ngram-lm-scale", + type=float, + default=1.3, + help=""" + Used only when method is whole-lattice-rescoring and attention-decoder. + It specifies the scale for n-gram LM scores. + (Note: You need to tune it on a dataset.) + """, + ) + + parser.add_argument( + "--attention-decoder-scale", + type=float, + default=1.2, + help=""" + Used only when method is attention-decoder. + It specifies the scale for attention decoder scores. + (Note: You need to tune it on a dataset.) + """, + ) + + parser.add_argument( + "--lattice-score-scale", + type=float, + default=0.5, + help=""" + Used only when method is attention-decoder. + It specifies the scale for lattice.scores when + extracting n-best lists. A smaller value results in + more unique number of paths with the risk of missing + the best path. + """, + ) + + parser.add_argument( + "--sos-id", + type=float, + default=1, + help=""" + Used only when method is attention-decoder. + It specifies ID for the SOS token. + """, + ) + + parser.add_argument( + "--eos-id", + type=float, + default=1, + help=""" + Used only when method is attention-decoder. + It specifies ID for the EOS token. + """, + ) + + parser.add_argument( + "sound_files", + type=str, + nargs="+", + help="The input sound file(s) to transcribe. " + "Supported formats are those supported by torchaudio.load(). " + "For example, wav and flac are supported. " + "The sample rate has to be 16kHz.", + ) + + return parser + + +def get_params() -> AttributeDict: + params = AttributeDict( + { + "feature_dim": 80, + "nhead": 8, + "num_classes": 5000, + "sample_rate": 16000, + "attention_dim": 512, + "subsampling_factor": 4, + "num_decoder_layers": 6, + "vgg_frontend": False, + "is_espnet_structure": True, + "mmi_loss": False, + "use_feat_batchnorm": True, + "search_beam": 20, + "output_beam": 8, + "min_active_states": 30, + "max_active_states": 10000, + "use_double_scores": True, + } + ) + return params + + +def read_sound_files( + filenames: List[str], expected_sample_rate: float +) -> List[torch.Tensor]: + """Read a list of sound files into a list 1-D float32 torch tensors. + Args: + filenames: + A list of sound filenames. + expected_sample_rate: + The expected sample rate of the sound files. + Returns: + Return a list of 1-D float32 torch tensors. + """ + ans = [] + for f in filenames: + wave, sample_rate = torchaudio.load(f) + assert sample_rate == expected_sample_rate, ( + f"expected sample rate: {expected_sample_rate}. " + f"Given: {sample_rate}" + ) + # We use only the first channel + ans.append(wave[0]) + return ans + + +def main(): + parser = get_parser() + args = parser.parse_args() + + params = get_params() + params.update(vars(args)) + logging.info(f"{params}") + + device = torch.device("cpu") + if torch.cuda.is_available(): + device = torch.device("cuda", 0) + + logging.info(f"device: {device}") + + logging.info("Creating model") + model = Conformer( + num_features=params.feature_dim, + nhead=params.nhead, + d_model=params.attention_dim, + num_classes=params.num_classes, + subsampling_factor=params.subsampling_factor, + num_decoder_layers=params.num_decoder_layers, + vgg_frontend=params.vgg_frontend, + is_espnet_structure=params.is_espnet_structure, + mmi_loss=params.mmi_loss, + use_feat_batchnorm=params.use_feat_batchnorm, + ) + + checkpoint = torch.load(args.checkpoint, map_location="cpu") + model.load_state_dict(checkpoint["model"]) + model.to(device) + model.eval() + + logging.info(f"Loading HLG from {params.HLG}") + HLG = k2.Fsa.from_dict(torch.load(params.HLG, map_location="cpu")) + HLG = HLG.to(device) + if not hasattr(HLG, "lm_scores"): + # For whole-lattice-rescoring and attention-decoder + HLG.lm_scores = HLG.scores.clone() + + if params.method in ["whole-lattice-rescoring", "attention-decoder"]: + logging.info(f"Loading G from {params.G}") + G = k2.Fsa.from_dict(torch.load(params.G, map_location="cpu")) + G = G.to(device) + # Add epsilon self-loops to G as we will compose + # it with the whole lattice later + G = k2.add_epsilon_self_loops(G) + G = k2.arc_sort(G) + G.lm_scores = G.scores.clone() + + logging.info("Constructing Fbank computer") + opts = kaldifeat.FbankOptions() + opts.device = device + opts.frame_opts.dither = 0 + opts.frame_opts.snip_edges = False + opts.frame_opts.samp_freq = params.sample_rate + opts.mel_opts.num_bins = params.feature_dim + + fbank = kaldifeat.Fbank(opts) + + logging.info(f"Reading sound files: {params.sound_files}") + waves = read_sound_files( + filenames=params.sound_files, expected_sample_rate=params.sample_rate + ) + waves = [w.to(device) for w in waves] + + logging.info(f"Decoding started") + features = fbank(waves) + + features = pad_sequence( + features, batch_first=True, padding_value=math.log(1e-10) + ) + + # Note: We don't use key padding mask for attention during decoding + with torch.no_grad(): + nnet_output, memory, memory_key_padding_mask = model(features) + + batch_size = nnet_output.shape[0] + supervision_segments = torch.tensor( + [[i, 0, nnet_output.shape[1]] for i in range(batch_size)], + dtype=torch.int32, + ) + + lattice = get_lattice( + nnet_output=nnet_output, + HLG=HLG, + supervision_segments=supervision_segments, + search_beam=params.search_beam, + output_beam=params.output_beam, + min_active_states=params.min_active_states, + max_active_states=params.max_active_states, + subsampling_factor=params.subsampling_factor, + ) + + if params.method == "1best": + logging.info("Use HLG decoding") + best_path = one_best_decoding( + lattice=lattice, use_double_scores=params.use_double_scores + ) + elif params.method == "whole-lattice-rescoring": + logging.info("Use HLG decoding + LM rescoring") + best_path_dict = rescore_with_whole_lattice( + lattice=lattice, + G_with_epsilon_loops=G, + lm_scale_list=[params.ngram_lm_scale], + ) + best_path = next(iter(best_path_dict.values())) + elif params.method == "attention-decoder": + logging.info("Use HLG + LM rescoring + attention decoder rescoring") + rescored_lattice = rescore_with_whole_lattice( + lattice=lattice, G_with_epsilon_loops=G, lm_scale_list=None + ) + best_path_dict = rescore_with_attention_decoder( + lattice=rescored_lattice, + num_paths=params.num_paths, + model=model, + memory=memory, + memory_key_padding_mask=memory_key_padding_mask, + sos_id=params.sos_id, + eos_id=params.eos_id, + scale=params.lattice_score_scale, + ngram_lm_scale=params.ngram_lm_scale, + attention_scale=params.attention_decoder_scale, + ) + best_path = next(iter(best_path_dict.values())) + + hyps = get_texts(best_path) + word_sym_table = k2.SymbolTable.from_file(params.words_file) + hyps = [[word_sym_table[i] for i in ids] for ids in hyps] + + s = "\n" + for filename, hyp in zip(params.sound_files, hyps): + words = " ".join(hyp) + s += f"{filename}:\n{words}\n\n" + logging.info(s) + + logging.info(f"Decoding Done") + + +if __name__ == "__main__": + formatter = ( + "%(asctime)s %(levelname)s [%(filename)s:%(lineno)d] %(message)s" + ) + + logging.basicConfig(format=formatter, level=logging.INFO) + main() diff --git a/egs/librispeech/ASR/conformer_ctc_embedding_scale/subsampling.py b/egs/librispeech/ASR/conformer_ctc_embedding_scale/subsampling.py new file mode 100644 index 000000000..5c3e1222e --- /dev/null +++ b/egs/librispeech/ASR/conformer_ctc_embedding_scale/subsampling.py @@ -0,0 +1,144 @@ +import torch +import torch.nn as nn + + +class Conv2dSubsampling(nn.Module): + """Convolutional 2D subsampling (to 1/4 length). + + Convert an input of shape [N, T, idim] to an output + with shape [N, T', odim], where + T' = ((T-1)//2 - 1)//2, which approximates T' == T//4 + + It is based on + https://github.com/espnet/espnet/blob/master/espnet/nets/pytorch_backend/transformer/subsampling.py # noqa + """ + + def __init__(self, idim: int, odim: int) -> None: + """ + Args: + idim: + Input dim. The input shape is [N, T, idim]. + Caution: It requires: T >=7, idim >=7 + odim: + Output dim. The output shape is [N, ((T-1)//2 - 1)//2, odim] + """ + assert idim >= 7 + super().__init__() + self.conv = nn.Sequential( + nn.Conv2d( + in_channels=1, out_channels=odim, kernel_size=3, stride=2 + ), + nn.ReLU(), + nn.Conv2d( + in_channels=odim, out_channels=odim, kernel_size=3, stride=2 + ), + nn.ReLU(), + ) + self.out = nn.Linear(odim * (((idim - 1) // 2 - 1) // 2), odim) + + def forward(self, x: torch.Tensor) -> torch.Tensor: + """Subsample x. + + Args: + x: + Its shape is [N, T, idim]. + + Returns: + Return a tensor of shape [N, ((T-1)//2 - 1)//2, odim] + """ + # On entry, x is [N, T, idim] + x = x.unsqueeze(1) # [N, T, idim] -> [N, 1, T, idim] i.e., [N, C, H, W] + x = self.conv(x) + # Now x is of shape [N, odim, ((T-1)//2 - 1)//2, ((idim-1)//2 - 1)//2] + b, c, t, f = x.size() + x = self.out(x.transpose(1, 2).contiguous().view(b, t, c * f)) + # Now x is of shape [N, ((T-1)//2 - 1))//2, odim] + return x + + +class VggSubsampling(nn.Module): + """Trying to follow the setup described in the following paper: + https://arxiv.org/pdf/1910.09799.pdf + + This paper is not 100% explicit so I am guessing to some extent, + and trying to compare with other VGG implementations. + + Convert an input of shape [N, T, idim] to an output + with shape [N, T', odim], where + T' = ((T-1)//2 - 1)//2, which approximates T' = T//4 + """ + + def __init__(self, idim: int, odim: int) -> None: + """Construct a VggSubsampling object. + + This uses 2 VGG blocks with 2 Conv2d layers each, + subsampling its input by a factor of 4 in the time dimensions. + + Args: + idim: + Input dim. The input shape is [N, T, idim]. + Caution: It requires: T >=7, idim >=7 + odim: + Output dim. The output shape is [N, ((T-1)//2 - 1)//2, odim] + """ + super().__init__() + + cur_channels = 1 + layers = [] + block_dims = [32, 64] + + # The decision to use padding=1 for the 1st convolution, then padding=0 + # for the 2nd and for the max-pooling, and ceil_mode=True, was driven by + # a back-compatibility concern so that the number of frames at the + # output would be equal to: + # (((T-1)//2)-1)//2. + # We can consider changing this by using padding=1 on the + # 2nd convolution, so the num-frames at the output would be T//4. + for block_dim in block_dims: + layers.append( + torch.nn.Conv2d( + in_channels=cur_channels, + out_channels=block_dim, + kernel_size=3, + padding=1, + stride=1, + ) + ) + layers.append(torch.nn.ReLU()) + layers.append( + torch.nn.Conv2d( + in_channels=block_dim, + out_channels=block_dim, + kernel_size=3, + padding=0, + stride=1, + ) + ) + layers.append( + torch.nn.MaxPool2d( + kernel_size=2, stride=2, padding=0, ceil_mode=True + ) + ) + cur_channels = block_dim + + self.layers = nn.Sequential(*layers) + + self.out = nn.Linear( + block_dims[-1] * (((idim - 1) // 2 - 1) // 2), odim + ) + + def forward(self, x: torch.Tensor) -> torch.Tensor: + """Subsample x. + + Args: + x: + Its shape is [N, T, idim]. + + Returns: + Return a tensor of shape [N, ((T-1)//2 - 1)//2, odim] + """ + x = x.unsqueeze(1) + x = self.layers(x) + b, c, t, f = x.size() + x = self.out(x.transpose(1, 2).contiguous().view(b, t, c * f)) + return x diff --git a/egs/librispeech/ASR/conformer_ctc_embedding_scale/test_subsampling.py b/egs/librispeech/ASR/conformer_ctc_embedding_scale/test_subsampling.py new file mode 100755 index 000000000..937845d77 --- /dev/null +++ b/egs/librispeech/ASR/conformer_ctc_embedding_scale/test_subsampling.py @@ -0,0 +1,33 @@ +#!/usr/bin/env python3 + +from subsampling import Conv2dSubsampling +from subsampling import VggSubsampling +import torch + + +def test_conv2d_subsampling(): + N = 3 + odim = 2 + + for T in range(7, 19): + for idim in range(7, 20): + model = Conv2dSubsampling(idim=idim, odim=odim) + x = torch.empty(N, T, idim) + y = model(x) + assert y.shape[0] == N + assert y.shape[1] == ((T - 1) // 2 - 1) // 2 + assert y.shape[2] == odim + + +def test_vgg_subsampling(): + N = 3 + odim = 2 + + for T in range(7, 19): + for idim in range(7, 20): + model = VggSubsampling(idim=idim, odim=odim) + x = torch.empty(N, T, idim) + y = model(x) + assert y.shape[0] == N + assert y.shape[1] == ((T - 1) // 2 - 1) // 2 + assert y.shape[2] == odim diff --git a/egs/librispeech/ASR/conformer_ctc_embedding_scale/test_transformer.py b/egs/librispeech/ASR/conformer_ctc_embedding_scale/test_transformer.py new file mode 100644 index 000000000..08e680607 --- /dev/null +++ b/egs/librispeech/ASR/conformer_ctc_embedding_scale/test_transformer.py @@ -0,0 +1,89 @@ +#!/usr/bin/env python3 + +import torch +from transformer import ( + Transformer, + encoder_padding_mask, + generate_square_subsequent_mask, + decoder_padding_mask, + add_sos, + add_eos, +) + +from torch.nn.utils.rnn import pad_sequence + + +def test_encoder_padding_mask(): + supervisions = { + "sequence_idx": torch.tensor([0, 1, 2]), + "start_frame": torch.tensor([0, 0, 0]), + "num_frames": torch.tensor([18, 7, 13]), + } + + max_len = ((18 - 1) // 2 - 1) // 2 + mask = encoder_padding_mask(max_len, supervisions) + expected_mask = torch.tensor( + [ + [False, False, False], # ((18 - 1)//2 - 1)//2 = 3, + [False, True, True], # ((7 - 1)//2 - 1)//2 = 1, + [False, False, True], # ((13 - 1)//2 - 1)//2 = 2, + ] + ) + assert torch.all(torch.eq(mask, expected_mask)) + + +def test_transformer(): + num_features = 40 + num_classes = 87 + model = Transformer(num_features=num_features, num_classes=num_classes) + + N = 31 + + for T in range(7, 30): + x = torch.rand(N, T, num_features) + y, _, _ = model(x) + assert y.shape == (N, (((T - 1) // 2) - 1) // 2, num_classes) + + +def test_generate_square_subsequent_mask(): + s = 5 + mask = generate_square_subsequent_mask(s) + inf = float("inf") + expected_mask = torch.tensor( + [ + [0.0, -inf, -inf, -inf, -inf], + [0.0, 0.0, -inf, -inf, -inf], + [0.0, 0.0, 0.0, -inf, -inf], + [0.0, 0.0, 0.0, 0.0, -inf], + [0.0, 0.0, 0.0, 0.0, 0.0], + ] + ) + assert torch.all(torch.eq(mask, expected_mask)) + + +def test_decoder_padding_mask(): + x = [torch.tensor([1, 2]), torch.tensor([3]), torch.tensor([2, 5, 8])] + y = pad_sequence(x, batch_first=True, padding_value=-1) + mask = decoder_padding_mask(y, ignore_id=-1) + expected_mask = torch.tensor( + [ + [False, False, True], + [False, True, True], + [False, False, False], + ] + ) + assert torch.all(torch.eq(mask, expected_mask)) + + +def test_add_sos(): + x = [[1, 2], [3], [2, 5, 8]] + y = add_sos(x, sos_id=0) + expected_y = [[0, 1, 2], [0, 3], [0, 2, 5, 8]] + assert y == expected_y + + +def test_add_eos(): + x = [[1, 2], [3], [2, 5, 8]] + y = add_eos(x, eos_id=0) + expected_y = [[1, 2, 0], [3, 0], [2, 5, 8, 0]] + assert y == expected_y diff --git a/egs/librispeech/ASR/conformer_ctc_embedding_scale/train.py b/egs/librispeech/ASR/conformer_ctc_embedding_scale/train.py new file mode 100755 index 000000000..795a2ab57 --- /dev/null +++ b/egs/librispeech/ASR/conformer_ctc_embedding_scale/train.py @@ -0,0 +1,708 @@ +#!/usr/bin/env python3 + +# This is just at the very beginning ... + +import argparse +import logging +from pathlib import Path +from shutil import copyfile +from typing import Optional + +import k2 +import torch +import torch.distributed as dist +import torch.multiprocessing as mp +import torch.nn as nn +from asr_datamodule import LibriSpeechAsrDataModule +from conformer import Conformer +from lhotse.utils import fix_random_seed +from torch.nn.parallel import DistributedDataParallel as DDP +from torch.nn.utils import clip_grad_norm_ +from torch.utils.tensorboard import SummaryWriter +from transformer import Noam + +from icefall.bpe_graph_compiler import BpeCtcTrainingGraphCompiler +from icefall.checkpoint import load_checkpoint +from icefall.checkpoint import save_checkpoint as save_checkpoint_impl +from icefall.dist import cleanup_dist, setup_dist +from icefall.lexicon import Lexicon +from icefall.utils import ( + AttributeDict, + encode_supervisions, + setup_logger, + str2bool, +) + + +def get_parser(): + parser = argparse.ArgumentParser( + formatter_class=argparse.ArgumentDefaultsHelpFormatter + ) + + parser.add_argument( + "--world-size", + type=int, + default=1, + help="Number of GPUs for DDP training.", + ) + + parser.add_argument( + "--master-port", + type=int, + default=12354, + help="Master port to use for DDP training.", + ) + + parser.add_argument( + "--tensorboard", + type=str2bool, + default=True, + help="Should various information be logged in tensorboard.", + ) + + return parser + + +def get_params() -> AttributeDict: + """Return a dict containing training parameters. + + All training related parameters that are not passed from the commandline + is saved in the variable `params`. + + Commandline options are merged into `params` after they are parsed, so + you can also access them via `params`. + + Explanation of options saved in `params`: + + - exp_dir: It specifies the directory where all training related + files, e.g., checkpoints, log, etc, are saved + + - lang_dir: It contains language related input files such as + "lexicon.txt" + + - lr: It specifies the initial learning rate + + - feature_dim: The model input dim. It has to match the one used + in computing features. + + - weight_decay: The weight_decay for the optimizer. + + - subsampling_factor: The subsampling factor for the model. + + - start_epoch: If it is not zero, load checkpoint `start_epoch-1` + and continue training from that checkpoint. + + - num_epochs: Number of epochs to train. + + - best_train_loss: Best training loss so far. It is used to select + the model that has the lowest training loss. It is + updated during the training. + + - best_valid_loss: Best validation loss so far. It is used to select + the model that has the lowest validation loss. It is + updated during the training. + + - best_train_epoch: It is the epoch that has the best training loss. + + - best_valid_epoch: It is the epoch that has the best validation loss. + + - batch_idx_train: Used to writing statistics to tensorboard. It + contains number of batches trained so far across + epochs. + + - log_interval: Print training loss if batch_idx % log_interval` is 0 + + - valid_interval: Run validation if batch_idx % valid_interval is 0 + + - reset_interval: Reset statistics if batch_idx % reset_interval is 0 + + - beam_size: It is used in k2.ctc_loss + + - reduction: It is used in k2.ctc_loss + + - use_double_scores: It is used in k2.ctc_loss + """ + params = AttributeDict( + { + "exp_dir": Path("conformer_ctc_embedding_scale/exp"), + "lang_dir": Path("data/lang_bpe"), + "feature_dim": 80, + "weight_decay": 1e-6, + "subsampling_factor": 4, + "start_epoch": 0, + "num_epochs": 20, + "best_train_loss": float("inf"), + "best_valid_loss": float("inf"), + "best_train_epoch": -1, + "best_valid_epoch": -1, + "batch_idx_train": 0, + "log_interval": 10, + "reset_interval": 200, + "valid_interval": 3000, + "beam_size": 10, + "reduction": "sum", + "use_double_scores": True, + "accum_grad": 1, + "att_rate": 0.7, + "attention_dim": 512, + "nhead": 8, + "num_decoder_layers": 6, + "is_espnet_structure": True, + "mmi_loss": False, + "use_feat_batchnorm": True, + "lr_factor": 5.0, + "warm_step": 80000, + } + ) + + return params + + +def load_checkpoint_if_available( + params: AttributeDict, + model: nn.Module, + optimizer: Optional[torch.optim.Optimizer] = None, + scheduler: Optional[torch.optim.lr_scheduler._LRScheduler] = None, +) -> None: + """Load checkpoint from file. + + If params.start_epoch is positive, it will load the checkpoint from + `params.start_epoch - 1`. Otherwise, this function does nothing. + + Apart from loading state dict for `model`, `optimizer` and `scheduler`, + it also updates `best_train_epoch`, `best_train_loss`, `best_valid_epoch`, + and `best_valid_loss` in `params`. + + Args: + params: + The return value of :func:`get_params`. + model: + The training model. + optimizer: + The optimizer that we are using. + scheduler: + The learning rate scheduler we are using. + Returns: + Return None. + """ + if params.start_epoch <= 0: + return + + filename = params.exp_dir / f"epoch-{params.start_epoch-1}.pt" + saved_params = load_checkpoint( + filename, + model=model, + optimizer=optimizer, + scheduler=scheduler, + ) + + keys = [ + "best_train_epoch", + "best_valid_epoch", + "batch_idx_train", + "best_train_loss", + "best_valid_loss", + ] + for k in keys: + params[k] = saved_params[k] + + return saved_params + + +def save_checkpoint( + params: AttributeDict, + model: nn.Module, + optimizer: Optional[torch.optim.Optimizer] = None, + scheduler: Optional[torch.optim.lr_scheduler._LRScheduler] = None, + rank: int = 0, +) -> None: + """Save model, optimizer, scheduler and training stats to file. + + Args: + params: + It is returned by :func:`get_params`. + model: + The training model. + """ + if rank != 0: + return + filename = params.exp_dir / f"epoch-{params.cur_epoch}.pt" + save_checkpoint_impl( + filename=filename, + model=model, + params=params, + optimizer=optimizer, + scheduler=scheduler, + rank=rank, + ) + + if params.best_train_epoch == params.cur_epoch: + best_train_filename = params.exp_dir / "best-train-loss.pt" + copyfile(src=filename, dst=best_train_filename) + + if params.best_valid_epoch == params.cur_epoch: + best_valid_filename = params.exp_dir / "best-valid-loss.pt" + copyfile(src=filename, dst=best_valid_filename) + + +def compute_loss( + params: AttributeDict, + model: nn.Module, + batch: dict, + graph_compiler: BpeCtcTrainingGraphCompiler, + is_training: bool, +): + """ + Compute CTC loss given the model and its inputs. + + Args: + params: + Parameters for training. See :func:`get_params`. + model: + The model for training. It is an instance of Conformer in our case. + batch: + A batch of data. See `lhotse.dataset.K2SpeechRecognitionDataset()` + for the content in it. + graph_compiler: + It is used to build a decoding graph from a ctc topo and training + transcript. The training transcript is contained in the given `batch`, + while the ctc topo is built when this compiler is instantiated. + is_training: + True for training. False for validation. When it is True, this + function enables autograd during computation; when it is False, it + disables autograd. + """ + device = graph_compiler.device + feature = batch["inputs"] + # at entry, feature is [N, T, C] + assert feature.ndim == 3 + feature = feature.to(device) + + supervisions = batch["supervisions"] + with torch.set_grad_enabled(is_training): + nnet_output, encoder_memory, memory_mask = model(feature, supervisions) + # nnet_output is [N, T, C] + + # NOTE: We need `encode_supervisions` to sort sequences with + # different duration in decreasing order, required by + # `k2.intersect_dense` called in `k2.ctc_loss` + supervision_segments, texts = encode_supervisions( + supervisions, subsampling_factor=params.subsampling_factor + ) + + token_ids = graph_compiler.texts_to_ids(texts) + + decoding_graph = graph_compiler.compile(token_ids) + + dense_fsa_vec = k2.DenseFsaVec( + nnet_output, + supervision_segments, + allow_truncate=params.subsampling_factor - 1, + ) + + ctc_loss = k2.ctc_loss( + decoding_graph=decoding_graph, + dense_fsa_vec=dense_fsa_vec, + output_beam=params.beam_size, + reduction=params.reduction, + use_double_scores=params.use_double_scores, + ) + + if params.att_rate != 0.0: + with torch.set_grad_enabled(is_training): + if hasattr(model, "module"): + att_loss = model.module.decoder_forward( + encoder_memory, + memory_mask, + token_ids=token_ids, + sos_id=graph_compiler.sos_id, + eos_id=graph_compiler.eos_id, + ) + else: + att_loss = model.decoder_forward( + encoder_memory, + memory_mask, + token_ids=token_ids, + sos_id=graph_compiler.sos_id, + eos_id=graph_compiler.eos_id, + ) + loss = (1.0 - params.att_rate) * ctc_loss + params.att_rate * att_loss + else: + loss = ctc_loss + att_loss = torch.tensor([0]) + + # train_frames and valid_frames are used for printing. + if is_training: + params.train_frames = supervision_segments[:, 2].sum().item() + else: + params.valid_frames = supervision_segments[:, 2].sum().item() + + assert loss.requires_grad == is_training + + return loss, ctc_loss.detach(), att_loss.detach() + + +def compute_validation_loss( + params: AttributeDict, + model: nn.Module, + graph_compiler: BpeCtcTrainingGraphCompiler, + valid_dl: torch.utils.data.DataLoader, + world_size: int = 1, +) -> None: + """Run the validation process. The validation loss + is saved in `params.valid_loss`. + """ + model.eval() + + tot_loss = 0.0 + tot_ctc_loss = 0.0 + tot_att_loss = 0.0 + tot_frames = 0.0 + for batch_idx, batch in enumerate(valid_dl): + loss, ctc_loss, att_loss = compute_loss( + params=params, + model=model, + batch=batch, + graph_compiler=graph_compiler, + is_training=False, + ) + assert loss.requires_grad is False + assert ctc_loss.requires_grad is False + assert att_loss.requires_grad is False + + loss_cpu = loss.detach().cpu().item() + tot_loss += loss_cpu + + tot_ctc_loss += ctc_loss.detach().cpu().item() + tot_att_loss += att_loss.detach().cpu().item() + + tot_frames += params.valid_frames + + if world_size > 1: + s = torch.tensor( + [tot_loss, tot_ctc_loss, tot_att_loss, tot_frames], + device=loss.device, + ) + dist.all_reduce(s, op=dist.ReduceOp.SUM) + s = s.cpu().tolist() + tot_loss = s[0] + tot_ctc_loss = s[1] + tot_att_loss = s[2] + tot_frames = s[3] + + params.valid_loss = tot_loss / tot_frames + params.valid_ctc_loss = tot_ctc_loss / tot_frames + params.valid_att_loss = tot_att_loss / tot_frames + + if params.valid_loss < params.best_valid_loss: + params.best_valid_epoch = params.cur_epoch + params.best_valid_loss = params.valid_loss + + +def train_one_epoch( + params: AttributeDict, + model: nn.Module, + optimizer: torch.optim.Optimizer, + graph_compiler: BpeCtcTrainingGraphCompiler, + train_dl: torch.utils.data.DataLoader, + valid_dl: torch.utils.data.DataLoader, + tb_writer: Optional[SummaryWriter] = None, + world_size: int = 1, +) -> None: + """Train the model for one epoch. + + The training loss from the mean of all frames is saved in + `params.train_loss`. It runs the validation process every + `params.valid_interval` batches. + + Args: + params: + It is returned by :func:`get_params`. + model: + The model for training. + optimizer: + The optimizer we are using. + graph_compiler: + It is used to convert transcripts to FSAs. + train_dl: + Dataloader for the training dataset. + valid_dl: + Dataloader for the validation dataset. + tb_writer: + Writer to write log messages to tensorboard. + world_size: + Number of nodes in DDP training. If it is 1, DDP is disabled. + """ + model.train() + + tot_loss = 0.0 # sum of losses over all batches + tot_ctc_loss = 0.0 + tot_att_loss = 0.0 + + tot_frames = 0.0 # sum of frames over all batches + params.tot_loss = 0.0 + params.tot_frames = 0.0 + for batch_idx, batch in enumerate(train_dl): + params.batch_idx_train += 1 + batch_size = len(batch["supervisions"]["text"]) + + loss, ctc_loss, att_loss = compute_loss( + params=params, + model=model, + batch=batch, + graph_compiler=graph_compiler, + is_training=True, + ) + + # NOTE: We use reduction==sum and loss is computed over utterances + # in the batch and there is no normalization to it so far. + + optimizer.zero_grad() + loss.backward() + clip_grad_norm_(model.parameters(), 5.0, 2.0) + optimizer.step() + + loss_cpu = loss.detach().cpu().item() + ctc_loss_cpu = ctc_loss.detach().cpu().item() + att_loss_cpu = att_loss.detach().cpu().item() + + tot_frames += params.train_frames + tot_loss += loss_cpu + tot_ctc_loss += ctc_loss_cpu + tot_att_loss += att_loss_cpu + + params.tot_frames += params.train_frames + params.tot_loss += loss_cpu + + tot_avg_loss = tot_loss / tot_frames + tot_avg_ctc_loss = tot_ctc_loss / tot_frames + tot_avg_att_loss = tot_att_loss / tot_frames + + if batch_idx % params.log_interval == 0: + logging.info( + f"Epoch {params.cur_epoch}, batch {batch_idx}, " + f"batch avg ctc loss {ctc_loss_cpu/params.train_frames:.4f}, " + f"batch avg att loss {att_loss_cpu/params.train_frames:.4f}, " + f"batch avg loss {loss_cpu/params.train_frames:.4f}, " + f"total avg ctc loss: {tot_avg_ctc_loss:.4f}, " + f"total avg att loss: {tot_avg_att_loss:.4f}, " + f"total avg loss: {tot_avg_loss:.4f}, " + f"batch size: {batch_size}" + ) + + if tb_writer is not None: + tb_writer.add_scalar( + "train/current_ctc_loss", + ctc_loss_cpu / params.train_frames, + params.batch_idx_train, + ) + tb_writer.add_scalar( + "train/current_att_loss", + att_loss_cpu / params.train_frames, + params.batch_idx_train, + ) + tb_writer.add_scalar( + "train/current_loss", + loss_cpu / params.train_frames, + params.batch_idx_train, + ) + tb_writer.add_scalar( + "train/tot_avg_ctc_loss", + tot_avg_ctc_loss, + params.batch_idx_train, + ) + + tb_writer.add_scalar( + "train/tot_avg_att_loss", + tot_avg_att_loss, + params.batch_idx_train, + ) + tb_writer.add_scalar( + "train/tot_avg_loss", + tot_avg_loss, + params.batch_idx_train, + ) + if batch_idx > 0 and batch_idx % params.reset_interval == 0: + tot_loss = 0.0 # sum of losses over all batches + tot_ctc_loss = 0.0 + tot_att_loss = 0.0 + + tot_frames = 0.0 # sum of frames over all batches + + if batch_idx > 0 and batch_idx % params.valid_interval == 0: + compute_validation_loss( + params=params, + model=model, + graph_compiler=graph_compiler, + valid_dl=valid_dl, + world_size=world_size, + ) + model.train() + logging.info( + f"Epoch {params.cur_epoch}, " + f"valid ctc loss {params.valid_ctc_loss:.4f}," + f"valid att loss {params.valid_att_loss:.4f}," + f"valid loss {params.valid_loss:.4f}," + f" best valid loss: {params.best_valid_loss:.4f} " + f"best valid epoch: {params.best_valid_epoch}" + ) + if tb_writer is not None: + tb_writer.add_scalar( + "train/valid_ctc_loss", + params.valid_ctc_loss, + params.batch_idx_train, + ) + tb_writer.add_scalar( + "train/valid_att_loss", + params.valid_att_loss, + params.batch_idx_train, + ) + tb_writer.add_scalar( + "train/valid_loss", + params.valid_loss, + params.batch_idx_train, + ) + + params.train_loss = params.tot_loss / params.tot_frames + + if params.train_loss < params.best_train_loss: + params.best_train_epoch = params.cur_epoch + params.best_train_loss = params.train_loss + + +def run(rank, world_size, args): + """ + Args: + rank: + It is a value between 0 and `world_size-1`, which is + passed automatically by `mp.spawn()` in :func:`main`. + The node with rank 0 is responsible for saving checkpoint. + world_size: + Number of GPUs for DDP training. + args: + The return value of get_parser().parse_args() + """ + params = get_params() + params.update(vars(args)) + + fix_random_seed(42) + if world_size > 1: + setup_dist(rank, world_size, params.master_port) + + setup_logger(f"{params.exp_dir}/log/log-train") + logging.info("Training started") + logging.info(params) + + if args.tensorboard and rank == 0: + tb_writer = SummaryWriter(log_dir=f"{params.exp_dir}/tensorboard") + else: + tb_writer = None + + lexicon = Lexicon(params.lang_dir) + max_token_id = max(lexicon.tokens) + num_classes = max_token_id + 1 # +1 for the blank + + device = torch.device("cpu") + if torch.cuda.is_available(): + device = torch.device("cuda", rank) + + graph_compiler = BpeCtcTrainingGraphCompiler( + params.lang_dir, + device=device, + sos_token="", + eos_token="", + ) + + logging.info("About to create model") + model = Conformer( + num_features=params.feature_dim, + nhead=params.nhead, + d_model=params.attention_dim, + num_classes=num_classes, + subsampling_factor=params.subsampling_factor, + num_decoder_layers=params.num_decoder_layers, + vgg_frontend=False, + is_espnet_structure=params.is_espnet_structure, + mmi_loss=params.mmi_loss, + use_feat_batchnorm=params.use_feat_batchnorm, + ) + + checkpoints = load_checkpoint_if_available(params=params, model=model) + + model.to(device) + if world_size > 1: + model = DDP(model, device_ids=[rank]) + + optimizer = Noam( + model.parameters(), + model_size=params.attention_dim, + factor=params.lr_factor, + warm_step=params.warm_step, + weight_decay=params.weight_decay, + ) + + if checkpoints: + optimizer.load_state_dict(checkpoints["optimizer"]) + + librispeech = LibriSpeechAsrDataModule(args) + train_dl = librispeech.train_dataloaders() + valid_dl = librispeech.valid_dataloaders() + + for epoch in range(params.start_epoch, params.num_epochs): + train_dl.sampler.set_epoch(epoch) + + cur_lr = optimizer._rate + if tb_writer is not None: + tb_writer.add_scalar( + "train/learning_rate", cur_lr, params.batch_idx_train + ) + tb_writer.add_scalar("train/epoch", epoch, params.batch_idx_train) + + if rank == 0: + logging.info("epoch {}, learning rate {}".format(epoch, cur_lr)) + + params.cur_epoch = epoch + + train_one_epoch( + params=params, + model=model, + optimizer=optimizer, + graph_compiler=graph_compiler, + train_dl=train_dl, + valid_dl=valid_dl, + tb_writer=tb_writer, + world_size=world_size, + ) + + save_checkpoint( + params=params, + model=model, + optimizer=optimizer, + rank=rank, + ) + + logging.info("Done!") + + if world_size > 1: + torch.distributed.barrier() + cleanup_dist() + + +def main(): + parser = get_parser() + LibriSpeechAsrDataModule.add_arguments(parser) + args = parser.parse_args() + + world_size = args.world_size + assert world_size >= 1 + if world_size > 1: + mp.spawn(run, args=(world_size, args), nprocs=world_size, join=True) + else: + run(rank=0, world_size=1, args=args) + + +torch.set_num_threads(1) +torch.set_num_interop_threads(1) + +if __name__ == "__main__": + main() diff --git a/egs/librispeech/ASR/conformer_ctc_embedding_scale/transformer.py b/egs/librispeech/ASR/conformer_ctc_embedding_scale/transformer.py new file mode 100644 index 000000000..f237ff8e3 --- /dev/null +++ b/egs/librispeech/ASR/conformer_ctc_embedding_scale/transformer.py @@ -0,0 +1,990 @@ +# Copyright (c) 2021 University of Chinese Academy of Sciences (author: Han Zhu) +# Apache 2.0 + +import math +from typing import Dict, List, Optional, Tuple + +import torch +import torch.nn as nn +from embedding import Embedding +from subsampling import Conv2dSubsampling, VggSubsampling +from torch.nn.utils.rnn import pad_sequence + +# Note: TorchScript requires Dict/List/etc. to be fully typed. +Supervisions = Dict[str, torch.Tensor] + + +class Transformer(nn.Module): + def __init__( + self, + num_features: int, + num_classes: int, + subsampling_factor: int = 4, + d_model: int = 256, + nhead: int = 4, + dim_feedforward: int = 2048, + num_encoder_layers: int = 12, + num_decoder_layers: int = 6, + dropout: float = 0.1, + normalize_before: bool = True, + vgg_frontend: bool = False, + mmi_loss: bool = True, + use_feat_batchnorm: bool = False, + ) -> None: + """ + Args: + num_features: + The input dimension of the model. + num_classes: + The output dimension of the model. + subsampling_factor: + Number of output frames is num_in_frames // subsampling_factor. + Currently, subsampling_factor MUST be 4. + d_model: + Attention dimension. + nhead: + Number of heads in multi-head attention. + Must satisfy d_model // nhead == 0. + dim_feedforward: + The output dimension of the feedforward layers in encoder/decoder. + num_encoder_layers: + Number of encoder layers. + num_decoder_layers: + Number of decoder layers. + dropout: + Dropout in encoder/decoder. + normalize_before: + If True, use pre-layer norm; False to use post-layer norm. + vgg_frontend: + True to use vgg style frontend for subsampling. + mmi_loss: + use_feat_batchnorm: + True to use batchnorm for the input layer. + """ + super().__init__() + self.use_feat_batchnorm = use_feat_batchnorm + if use_feat_batchnorm: + self.feat_batchnorm = nn.BatchNorm1d(num_features) + + self.num_features = num_features + self.num_classes = num_classes + self.subsampling_factor = subsampling_factor + if subsampling_factor != 4: + raise NotImplementedError("Support only 'subsampling_factor=4'.") + + # self.encoder_embed converts the input of shape [N, T, num_classes] + # to the shape [N, T//subsampling_factor, d_model]. + # That is, it does two things simultaneously: + # (1) subsampling: T -> T//subsampling_factor + # (2) embedding: num_classes -> d_model + if vgg_frontend: + self.encoder_embed = VggSubsampling(num_features, d_model) + else: + self.encoder_embed = Conv2dSubsampling(num_features, d_model) + + self.encoder_pos = PositionalEncoding(d_model, dropout) + + encoder_layer = TransformerEncoderLayer( + d_model=d_model, + nhead=nhead, + dim_feedforward=dim_feedforward, + dropout=dropout, + normalize_before=normalize_before, + ) + + if normalize_before: + encoder_norm = nn.LayerNorm(d_model) + else: + encoder_norm = None + + self.encoder = nn.TransformerEncoder( + encoder_layer=encoder_layer, + num_layers=num_encoder_layers, + norm=encoder_norm, + ) + + # TODO(fangjun): remove dropout + self.encoder_output_layer = nn.Sequential( + nn.Dropout(p=dropout), nn.Linear(d_model, num_classes) + ) + + if num_decoder_layers > 0: + if mmi_loss: + self.decoder_num_class = ( + self.num_classes + 1 + ) # +1 for the sos/eos symbol + else: + self.decoder_num_class = ( + self.num_classes + ) # bpe model already has sos/eos symbol + + self.decoder_embed = Embedding( + num_embeddings=self.decoder_num_class, embedding_dim=d_model + ) + self.decoder_pos = PositionalEncoding(d_model, dropout) + + decoder_layer = TransformerDecoderLayer( + d_model=d_model, + nhead=nhead, + dim_feedforward=dim_feedforward, + dropout=dropout, + normalize_before=normalize_before, + ) + + if normalize_before: + decoder_norm = nn.LayerNorm(d_model) + else: + decoder_norm = None + + self.decoder = nn.TransformerDecoder( + decoder_layer=decoder_layer, + num_layers=num_decoder_layers, + norm=decoder_norm, + ) + + self.decoder_output_layer = torch.nn.Linear( + d_model, self.decoder_num_class + ) + + self.decoder_criterion = LabelSmoothingLoss(self.decoder_num_class) + else: + self.decoder_criterion = None + + def forward( + self, x: torch.Tensor, supervision: Optional[Supervisions] = None + ) -> Tuple[torch.Tensor, torch.Tensor, Optional[torch.Tensor]]: + """ + Args: + x: + The input tensor. Its shape is [N, T, C]. + supervision: + Supervision in lhotse format. + See https://github.com/lhotse-speech/lhotse/blob/master/lhotse/dataset/speech_recognition.py#L32 # noqa + (CAUTION: It contains length information, i.e., start and number of + frames, before subsampling) + + Returns: + Return a tuple containing 3 tensors: + - CTC output for ctc decoding. Its shape is [N, T, C] + - Encoder output with shape [T, N, C]. It can be used as key and + value for the decoder. + - Encoder output padding mask. It can be used as + memory_key_padding_mask for the decoder. Its shape is [N, T]. + It is None if `supervision` is None. + """ + if self.use_feat_batchnorm: + x = x.permute(0, 2, 1) # [N, T, C] -> [N, C, T] + x = self.feat_batchnorm(x) + x = x.permute(0, 2, 1) # [N, C, T] -> [N, T, C] + encoder_memory, memory_key_padding_mask = self.run_encoder( + x, supervision + ) + x = self.ctc_output(encoder_memory) + return x, encoder_memory, memory_key_padding_mask + + def run_encoder( + self, x: torch.Tensor, supervisions: Optional[Supervisions] = None + ) -> Tuple[torch.Tensor, Optional[torch.Tensor]]: + """Run the transformer encoder. + + Args: + x: + The model input. Its shape is [N, T, C]. + supervisions: + Supervision in lhotse format. + See https://github.com/lhotse-speech/lhotse/blob/master/lhotse/dataset/speech_recognition.py#L32 # noqa + CAUTION: It contains length information, i.e., start and number of + frames, before subsampling + It is read directly from the batch, without any sorting. It is used + to compute the encoder padding mask, which is used as memory key + padding mask for the decoder. + Returns: + Return a tuple with two tensors: + - The encoder output, with shape [T, N, C] + - encoder padding mask, with shape [N, T]. + The mask is None if `supervisions` is None. + It is used as memory key padding mask in the decoder. + """ + x = self.encoder_embed(x) + x = self.encoder_pos(x) + x = x.permute(1, 0, 2) # (N, T, C) -> (T, N, C) + mask = encoder_padding_mask(x.size(0), supervisions) + mask = mask.to(x.device) if mask is not None else None + x = self.encoder(x, src_key_padding_mask=mask) # (T, N, C) + + return x, mask + + def ctc_output(self, x: torch.Tensor) -> torch.Tensor: + """ + Args: + x: + The output tensor from the transformer encoder. + Its shape is [T, N, C] + + Returns: + Return a tensor that can be used for CTC decoding. + Its shape is [N, T, C] + """ + x = self.encoder_output_layer(x) + x = x.permute(1, 0, 2) # (T, N, C) ->(N, T, C) + x = nn.functional.log_softmax(x, dim=-1) # (N, T, C) + return x + + def decoder_forward( + self, + memory: torch.Tensor, + memory_key_padding_mask: torch.Tensor, + token_ids: List[List[int]], + sos_id: int, + eos_id: int, + ) -> torch.Tensor: + """ + Args: + memory: + It's the output of the encoder with shape [T, N, C] + memory_key_padding_mask: + The padding mask from the encoder. + token_ids: + A list-of-list IDs. Each sublist contains IDs for an utterance. + The IDs can be either phone IDs or word piece IDs. + sos_id: + sos token id + eos_id: + eos token id + + Returns: + A scalar, the **sum** of label smoothing loss over utterances + in the batch without any normalization. + """ + ys_in = add_sos(token_ids, sos_id=sos_id) + ys_in = [torch.tensor(y) for y in ys_in] + ys_in_pad = pad_sequence(ys_in, batch_first=True, padding_value=eos_id) + + ys_out = add_eos(token_ids, eos_id=eos_id) + ys_out = [torch.tensor(y) for y in ys_out] + ys_out_pad = pad_sequence(ys_out, batch_first=True, padding_value=-1) + + device = memory.device + ys_in_pad = ys_in_pad.to(device) + ys_out_pad = ys_out_pad.to(device) + + tgt_mask = generate_square_subsequent_mask(ys_in_pad.shape[-1]).to( + device + ) + + tgt_key_padding_mask = decoder_padding_mask(ys_in_pad, ignore_id=eos_id) + # TODO: Use length information to create the decoder padding mask + # We set the first column to False since the first column in ys_in_pad + # contains sos_id, which is the same as eos_id in our current setting. + tgt_key_padding_mask[:, 0] = False + + tgt = self.decoder_embed(ys_in_pad) # (N, T) -> (N, T, C) + tgt = self.decoder_pos(tgt) + tgt = tgt.permute(1, 0, 2) # (N, T, C) -> (T, N, C) + pred_pad = self.decoder( + tgt=tgt, + memory=memory, + tgt_mask=tgt_mask, + tgt_key_padding_mask=tgt_key_padding_mask, + memory_key_padding_mask=memory_key_padding_mask, + ) # (T, N, C) + pred_pad = pred_pad.permute(1, 0, 2) # (T, N, C) -> (N, T, C) + pred_pad = self.decoder_output_layer(pred_pad) # (N, T, C) + + decoder_loss = self.decoder_criterion(pred_pad, ys_out_pad) + + return decoder_loss + + def decoder_nll( + self, + memory: torch.Tensor, + memory_key_padding_mask: torch.Tensor, + token_ids: List[List[int]], + sos_id: int, + eos_id: int, + ) -> torch.Tensor: + """ + Args: + memory: + It's the output of the encoder with shape [T, N, C] + memory_key_padding_mask: + The padding mask from the encoder. + token_ids: + A list-of-list IDs (e.g., word piece IDs). + Each sublist represents an utterance. + sos_id: + The token ID for SOS. + eos_id: + The token ID for EOS. + Returns: + A 2-D tensor of shape (len(token_ids), max_token_length) + representing the cross entropy loss (i.e., negative log-likelihood). + """ + # The common part between this function and decoder_forward could be + # extracted as a separate function. + + ys_in = add_sos(token_ids, sos_id=sos_id) + ys_in = [torch.tensor(y) for y in ys_in] + ys_in_pad = pad_sequence(ys_in, batch_first=True, padding_value=eos_id) + + ys_out = add_eos(token_ids, eos_id=eos_id) + ys_out = [torch.tensor(y) for y in ys_out] + ys_out_pad = pad_sequence(ys_out, batch_first=True, padding_value=-1) + + device = memory.device + ys_in_pad = ys_in_pad.to(device, dtype=torch.int64) + ys_out_pad = ys_out_pad.to(device, dtype=torch.int64) + + tgt_mask = generate_square_subsequent_mask(ys_in_pad.shape[-1]).to( + device + ) + + tgt_key_padding_mask = decoder_padding_mask(ys_in_pad, ignore_id=eos_id) + # TODO: Use length information to create the decoder padding mask + # We set the first column to False since the first column in ys_in_pad + # contains sos_id, which is the same as eos_id in our current setting. + tgt_key_padding_mask[:, 0] = False + + tgt = self.decoder_embed(ys_in_pad) # (B, T) -> (B, T, F) + tgt = self.decoder_pos(tgt) + tgt = tgt.permute(1, 0, 2) # (B, T, F) -> (T, B, F) + pred_pad = self.decoder( + tgt=tgt, + memory=memory, + tgt_mask=tgt_mask, + tgt_key_padding_mask=tgt_key_padding_mask, + memory_key_padding_mask=memory_key_padding_mask, + ) # (T, B, F) + pred_pad = pred_pad.permute(1, 0, 2) # (T, B, F) -> (B, T, F) + pred_pad = self.decoder_output_layer(pred_pad) # (B, T, F) + # nll: negative log-likelihood + nll = torch.nn.functional.cross_entropy( + pred_pad.view(-1, self.decoder_num_class), + ys_out_pad.view(-1), + ignore_index=-1, + reduction="none", + ) + + nll = nll.view(pred_pad.shape[0], -1) + + return nll + + +class TransformerEncoderLayer(nn.Module): + """ + Modified from torch.nn.TransformerEncoderLayer. + Add support of normalize_before, + i.e., use layer_norm before the first block. + + Args: + d_model: + the number of expected features in the input (required). + nhead: + the number of heads in the multiheadattention models (required). + dim_feedforward: + the dimension of the feedforward network model (default=2048). + dropout: + the dropout value (default=0.1). + activation: + the activation function of intermediate layer, relu or + gelu (default=relu). + normalize_before: + whether to use layer_norm before the first block. + + Examples:: + >>> encoder_layer = TransformerEncoderLayer(d_model=512, nhead=8) + >>> src = torch.rand(10, 32, 512) + >>> out = encoder_layer(src) + """ + + def __init__( + self, + d_model: int, + nhead: int, + dim_feedforward: int = 2048, + dropout: float = 0.1, + activation: str = "relu", + normalize_before: bool = True, + ) -> None: + super(TransformerEncoderLayer, self).__init__() + self.self_attn = nn.MultiheadAttention(d_model, nhead, dropout=0.0) + # Implementation of Feedforward model + self.linear1 = nn.Linear(d_model, dim_feedforward) + self.dropout = nn.Dropout(dropout) + self.linear2 = nn.Linear(dim_feedforward, d_model) + + self.norm1 = nn.LayerNorm(d_model) + self.norm2 = nn.LayerNorm(d_model) + self.dropout1 = nn.Dropout(dropout) + self.dropout2 = nn.Dropout(dropout) + + self.activation = _get_activation_fn(activation) + + self.normalize_before = normalize_before + + def __setstate__(self, state): + if "activation" not in state: + state["activation"] = nn.functional.relu + super(TransformerEncoderLayer, self).__setstate__(state) + + def forward( + self, + src: torch.Tensor, + src_mask: Optional[torch.Tensor] = None, + src_key_padding_mask: Optional[torch.Tensor] = None, + ) -> torch.Tensor: + """ + Pass the input through the encoder layer. + + Args: + src: the sequence to the encoder layer (required). + src_mask: the mask for the src sequence (optional). + src_key_padding_mask: the mask for the src keys per batch (optional) + + Shape: + src: (S, N, E). + src_mask: (S, S). + src_key_padding_mask: (N, S). + S is the source sequence length, T is the target sequence length, + N is the batch size, E is the feature number + """ + residual = src + if self.normalize_before: + src = self.norm1(src) + src2 = self.self_attn( + src, + src, + src, + attn_mask=src_mask, + key_padding_mask=src_key_padding_mask, + )[0] + src = residual + self.dropout1(src2) + if not self.normalize_before: + src = self.norm1(src) + + residual = src + if self.normalize_before: + src = self.norm2(src) + src2 = self.linear2(self.dropout(self.activation(self.linear1(src)))) + src = residual + self.dropout2(src2) + if not self.normalize_before: + src = self.norm2(src) + return src + + +class TransformerDecoderLayer(nn.Module): + """ + Modified from torch.nn.TransformerDecoderLayer. + Add support of normalize_before, + i.e., use layer_norm before the first block. + + Args: + d_model: + the number of expected features in the input (required). + nhead: + the number of heads in the multiheadattention models (required). + dim_feedforward: + the dimension of the feedforward network model (default=2048). + dropout: + the dropout value (default=0.1). + activation: + the activation function of intermediate layer, relu or + gelu (default=relu). + + Examples:: + >>> decoder_layer = nn.TransformerDecoderLayer(d_model=512, nhead=8) + >>> memory = torch.rand(10, 32, 512) + >>> tgt = torch.rand(20, 32, 512) + >>> out = decoder_layer(tgt, memory) + """ + + def __init__( + self, + d_model: int, + nhead: int, + dim_feedforward: int = 2048, + dropout: float = 0.1, + activation: str = "relu", + normalize_before: bool = True, + ) -> None: + super(TransformerDecoderLayer, self).__init__() + self.self_attn = nn.MultiheadAttention(d_model, nhead, dropout=0.0) + self.src_attn = nn.MultiheadAttention(d_model, nhead, dropout=0.0) + # Implementation of Feedforward model + self.linear1 = nn.Linear(d_model, dim_feedforward) + self.dropout = nn.Dropout(dropout) + self.linear2 = nn.Linear(dim_feedforward, d_model) + + self.norm1 = nn.LayerNorm(d_model) + self.norm2 = nn.LayerNorm(d_model) + self.norm3 = nn.LayerNorm(d_model) + self.dropout1 = nn.Dropout(dropout) + self.dropout2 = nn.Dropout(dropout) + self.dropout3 = nn.Dropout(dropout) + + self.activation = _get_activation_fn(activation) + + self.normalize_before = normalize_before + + def __setstate__(self, state): + if "activation" not in state: + state["activation"] = nn.functional.relu + super(TransformerDecoderLayer, self).__setstate__(state) + + def forward( + self, + tgt: torch.Tensor, + memory: torch.Tensor, + tgt_mask: Optional[torch.Tensor] = None, + memory_mask: Optional[torch.Tensor] = None, + tgt_key_padding_mask: Optional[torch.Tensor] = None, + memory_key_padding_mask: Optional[torch.Tensor] = None, + ) -> torch.Tensor: + """Pass the inputs (and mask) through the decoder layer. + + Args: + tgt: + the sequence to the decoder layer (required). + memory: + the sequence from the last layer of the encoder (required). + tgt_mask: + the mask for the tgt sequence (optional). + memory_mask: + the mask for the memory sequence (optional). + tgt_key_padding_mask: + the mask for the tgt keys per batch (optional). + memory_key_padding_mask: + the mask for the memory keys per batch (optional). + + Shape: + tgt: (T, N, E). + memory: (S, N, E). + tgt_mask: (T, T). + memory_mask: (T, S). + tgt_key_padding_mask: (N, T). + memory_key_padding_mask: (N, S). + S is the source sequence length, T is the target sequence length, + N is the batch size, E is the feature number + """ + residual = tgt + if self.normalize_before: + tgt = self.norm1(tgt) + tgt2 = self.self_attn( + tgt, + tgt, + tgt, + attn_mask=tgt_mask, + key_padding_mask=tgt_key_padding_mask, + )[0] + tgt = residual + self.dropout1(tgt2) + if not self.normalize_before: + tgt = self.norm1(tgt) + + residual = tgt + if self.normalize_before: + tgt = self.norm2(tgt) + tgt2 = self.src_attn( + tgt, + memory, + memory, + attn_mask=memory_mask, + key_padding_mask=memory_key_padding_mask, + )[0] + tgt = residual + self.dropout2(tgt2) + if not self.normalize_before: + tgt = self.norm2(tgt) + + residual = tgt + if self.normalize_before: + tgt = self.norm3(tgt) + tgt2 = self.linear2(self.dropout(self.activation(self.linear1(tgt)))) + tgt = residual + self.dropout3(tgt2) + if not self.normalize_before: + tgt = self.norm3(tgt) + return tgt + + +def _get_activation_fn(activation: str): + if activation == "relu": + return nn.functional.relu + elif activation == "gelu": + return nn.functional.gelu + + raise RuntimeError( + "activation should be relu/gelu, not {}".format(activation) + ) + + +class PositionalEncoding(nn.Module): + """This class implements the positional encoding + proposed in the following paper: + + - Attention Is All You Need: https://arxiv.org/pdf/1706.03762.pdf + + PE(pos, 2i) = sin(pos / (10000^(2i/d_modle)) + PE(pos, 2i+1) = cos(pos / (10000^(2i/d_modle)) + + Note:: + + 1 / (10000^(2i/d_model)) = exp(-log(10000^(2i/d_model))) + = exp(-1* 2i / d_model * log(100000)) + = exp(2i * -(log(10000) / d_model)) + """ + + def __init__(self, d_model: int, dropout: float = 0.1) -> None: + """ + Args: + d_model: + Embedding dimension. + dropout: + Dropout probability to be applied to the output of this module. + """ + super().__init__() + self.d_model = d_model + self.pos_scale = 1. / math.sqrt(self.d_model) + self.dropout = nn.Dropout(p=dropout) + self.pe = None + + def extend_pe(self, x: torch.Tensor) -> None: + """Extend the time t in the positional encoding if required. + + The shape of `self.pe` is [1, T1, d_model]. The shape of the input x + is [N, T, d_model]. If T > T1, then we change the shape of self.pe + to [N, T, d_model]. Otherwise, nothing is done. + + Args: + x: + It is a tensor of shape [N, T, C]. + Returns: + Return None. + """ + if self.pe is not None: + if self.pe.size(1) >= x.size(1): + if self.pe.dtype != x.dtype or self.pe.device != x.device: + self.pe = self.pe.to(dtype=x.dtype, device=x.device) + return + pe = torch.zeros(x.size(1), self.d_model, dtype=torch.float32) + position = torch.arange(0, x.size(1), dtype=torch.float32).unsqueeze(1) + div_term = torch.exp( + torch.arange(0, self.d_model, 2, dtype=torch.float32) + * -(math.log(10000.0) / self.d_model) + ) + pe[:, 0::2] = torch.sin(position * div_term) + pe[:, 1::2] = torch.cos(position * div_term) + pe = pe.unsqueeze(0) + # Now pe is of shape [1, T, d_model], where T is x.size(1) + self.pe = pe.to(device=x.device, dtype=x.dtype) + + def forward(self, x: torch.Tensor) -> torch.Tensor: + """ + Add positional encoding. + + Args: + x: + Its shape is [N, T, C] + + Returns: + Return a tensor of shape [N, T, C] + """ + self.extend_pe(x) + x = x + self.pe[:, : x.size(1), :] * self.pos_scale + return self.dropout(x) + + +class Noam(object): + """ + Implements Noam optimizer. + + Proposed in + "Attention Is All You Need", https://arxiv.org/pdf/1706.03762.pdf + + Modified from + https://github.com/espnet/espnet/blob/master/espnet/nets/pytorch_backend/transformer/optimizer.py # noqa + + Args: + params: + iterable of parameters to optimize or dicts defining parameter groups + model_size: + attention dimension of the transformer model + factor: + learning rate factor + warm_step: + warmup steps + """ + + def __init__( + self, + params, + model_size: int = 256, + factor: float = 10.0, + warm_step: int = 25000, + weight_decay=0, + ) -> None: + """Construct an Noam object.""" + self.optimizer = torch.optim.Adam( + params, lr=0, betas=(0.9, 0.98), eps=1e-9, weight_decay=weight_decay + ) + self._step = 0 + self.warmup = warm_step + self.factor = factor + self.model_size = model_size + self._rate = 0 + + @property + def param_groups(self): + """Return param_groups.""" + return self.optimizer.param_groups + + def step(self): + """Update parameters and rate.""" + self._step += 1 + rate = self.rate() + for p in self.optimizer.param_groups: + p["lr"] = rate + self._rate = rate + self.optimizer.step() + + def rate(self, step=None): + """Implement `lrate` above.""" + if step is None: + step = self._step + return ( + self.factor + * self.model_size ** (-0.5) + * min(step ** (-0.5), step * self.warmup ** (-1.5)) + ) + + def zero_grad(self): + """Reset gradient.""" + self.optimizer.zero_grad() + + def state_dict(self): + """Return state_dict.""" + return { + "_step": self._step, + "warmup": self.warmup, + "factor": self.factor, + "model_size": self.model_size, + "_rate": self._rate, + "optimizer": self.optimizer.state_dict(), + } + + def load_state_dict(self, state_dict): + """Load state_dict.""" + for key, value in state_dict.items(): + if key == "optimizer": + self.optimizer.load_state_dict(state_dict["optimizer"]) + else: + setattr(self, key, value) + + +class LabelSmoothingLoss(nn.Module): + """ + Label-smoothing loss. KL-divergence between q_{smoothed ground truth prob.}(w) + and p_{prob. computed by model}(w) is minimized. + Modified from + https://github.com/espnet/espnet/blob/master/espnet/nets/pytorch_backend/transformer/label_smoothing_loss.py # noqa + + Args: + size: the number of class + padding_idx: padding_idx: ignored class id + smoothing: smoothing rate (0.0 means the conventional CE) + normalize_length: normalize loss by sequence length if True + criterion: loss function to be smoothed + """ + + def __init__( + self, + size: int, + padding_idx: int = -1, + smoothing: float = 0.1, + normalize_length: bool = False, + criterion: nn.Module = nn.KLDivLoss(reduction="none"), + ) -> None: + """Construct an LabelSmoothingLoss object.""" + super(LabelSmoothingLoss, self).__init__() + self.criterion = criterion + self.padding_idx = padding_idx + assert 0.0 < smoothing <= 1.0 + self.confidence = 1.0 - smoothing + self.smoothing = smoothing + self.size = size + self.true_dist = None + self.normalize_length = normalize_length + + def forward(self, x: torch.Tensor, target: torch.Tensor) -> torch.Tensor: + """ + Compute loss between x and target. + + Args: + x: + prediction of dimension + (batch_size, input_length, number_of_classes). + target: + target masked with self.padding_id of + dimension (batch_size, input_length). + + Returns: + A scalar tensor containing the loss without normalization. + """ + assert x.size(2) == self.size + # batch_size = x.size(0) + x = x.view(-1, self.size) + target = target.view(-1) + with torch.no_grad(): + true_dist = x.clone() + true_dist.fill_(self.smoothing / (self.size - 1)) + ignore = target == self.padding_idx # (B,) + total = len(target) - ignore.sum().item() + target = target.masked_fill(ignore, 0) # avoid -1 index + true_dist.scatter_(1, target.unsqueeze(1), self.confidence) + kl = self.criterion(torch.log_softmax(x, dim=1), true_dist) + # denom = total if self.normalize_length else batch_size + denom = total if self.normalize_length else 1 + return kl.masked_fill(ignore.unsqueeze(1), 0).sum() / denom + + +def encoder_padding_mask( + max_len: int, supervisions: Optional[Supervisions] = None +) -> Optional[torch.Tensor]: + """Make mask tensor containing indexes of padded part. + + TODO:: + This function **assumes** that the model uses + a subsampling factor of 4. We should remove that + assumption later. + + Args: + max_len: + Maximum length of input features. + CAUTION: It is the length after subsampling. + supervisions: + Supervision in lhotse format. + See https://github.com/lhotse-speech/lhotse/blob/master/lhotse/dataset/speech_recognition.py#L32 # noqa + (CAUTION: It contains length information, i.e., start and number of + frames, before subsampling) + + Returns: + Tensor: Mask tensor of dimension (batch_size, input_length), True denote the masked indices. + """ + if supervisions is None: + return None + + supervision_segments = torch.stack( + ( + supervisions["sequence_idx"], + supervisions["start_frame"], + supervisions["num_frames"], + ), + 1, + ).to(torch.int32) + + lengths = [ + 0 for _ in range(int(supervision_segments[:, 0].max().item()) + 1) + ] + for idx in range(supervision_segments.size(0)): + # Note: TorchScript doesn't allow to unpack tensors as tuples + sequence_idx = supervision_segments[idx, 0].item() + start_frame = supervision_segments[idx, 1].item() + num_frames = supervision_segments[idx, 2].item() + lengths[sequence_idx] = start_frame + num_frames + + lengths = [((i - 1) // 2 - 1) // 2 for i in lengths] + bs = int(len(lengths)) + seq_range = torch.arange(0, max_len, dtype=torch.int64) + seq_range_expand = seq_range.unsqueeze(0).expand(bs, max_len) + # Note: TorchScript doesn't implement Tensor.new() + seq_length_expand = torch.tensor( + lengths, device=seq_range_expand.device, dtype=seq_range_expand.dtype + ).unsqueeze(-1) + mask = seq_range_expand >= seq_length_expand + + return mask + + +def decoder_padding_mask( + ys_pad: torch.Tensor, ignore_id: int = -1 +) -> torch.Tensor: + """Generate a length mask for input. + + The masked position are filled with True, + Unmasked positions are filled with False. + + Args: + ys_pad: + padded tensor of dimension (batch_size, input_length). + ignore_id: + the ignored number (the padding number) in ys_pad + + Returns: + Tensor: + a bool tensor of the same shape as the input tensor. + """ + ys_mask = ys_pad == ignore_id + return ys_mask + + +def generate_square_subsequent_mask(sz: int) -> torch.Tensor: + """Generate a square mask for the sequence. The masked positions are + filled with float('-inf'). Unmasked positions are filled with float(0.0). + The mask can be used for masked self-attention. + + For instance, if sz is 3, it returns:: + + tensor([[0., -inf, -inf], + [0., 0., -inf], + [0., 0., 0]]) + + Args: + sz: mask size + + Returns: + A square mask of dimension (sz, sz) + """ + mask = (torch.triu(torch.ones(sz, sz)) == 1).transpose(0, 1) + mask = ( + mask.float() + .masked_fill(mask == 0, float("-inf")) + .masked_fill(mask == 1, float(0.0)) + ) + return mask + + +def add_sos(token_ids: List[List[int]], sos_id: int) -> List[List[int]]: + """Prepend sos_id to each utterance. + + Args: + token_ids: + A list-of-list of token IDs. Each sublist contains + token IDs (e.g., word piece IDs) of an utterance. + sos_id: + The ID of the SOS token. + + Return: + Return a new list-of-list, where each sublist starts + with SOS ID. + """ + ans = [] + for utt in token_ids: + ans.append([sos_id] + utt) + return ans + + +def add_eos(token_ids: List[List[int]], eos_id: int) -> List[List[int]]: + """Append eos_id to each utterance. + + Args: + token_ids: + A list-of-list of token IDs. Each sublist contains + token IDs (e.g., word piece IDs) of an utterance. + eos_id: + The ID of the EOS token. + + Return: + Return a new list-of-list, where each sublist ends + with EOS ID. + """ + ans = [] + for utt in token_ids: + ans.append(utt + [eos_id]) + return ans