add model file

model_handling.py

@@ -0,0 +1,165 @@
+from transformers import Wav2Vec2PreTrainedModel, Wav2Vec2Model
+from torch import nn
+import warnings
+import torch
+from transformers.modeling_outputs import CausalLMOutput
+from collections import OrderedDict
+
+_HIDDEN_STATES_START_POSITION = 2
+
+
+class Wav2Vec2ForCTC(Wav2Vec2PreTrainedModel):
+    def __init__(self, config):
+        super().__init__(config)
+
+        self.wav2vec2 = Wav2Vec2Model(config)
+        self.dropout = nn.Dropout(config.final_dropout)
+
+        self.feature_transform = nn.Sequential(OrderedDict([
+            ('linear1', nn.Linear(config.hidden_size, config.hidden_size)),
+            ('bn1', nn.BatchNorm1d(config.hidden_size)),
+            ('activation1', nn.LeakyReLU()),
+            ('drop1', nn.Dropout(config.final_dropout)),
+            ('linear2', nn.Linear(config.hidden_size, config.hidden_size)),
+            ('bn2', nn.BatchNorm1d(config.hidden_size)),
+            ('activation2', nn.LeakyReLU()),
+            ('drop2', nn.Dropout(config.final_dropout)),
+            ('linear3', nn.Linear(config.hidden_size, config.hidden_size)),
+            ('bn3', nn.BatchNorm1d(config.hidden_size)),
+            ('activation3', nn.LeakyReLU()),
+            ('drop3', nn.Dropout(config.final_dropout))
+        ]))
+
+        if config.vocab_size is None:
+            raise ValueError(
+                f"You are trying to instantiate {self.__class__} with a configuration that "
+                "does not define the vocabulary size of the language model head. Please "
+                "instantiate the model as follows: `Wav2Vec2ForCTC.from_pretrained(..., vocab_size=vocab_size)`. "
+                "or define `vocab_size` of your model's configuration."
+            )
+        self.lm_head = nn.Linear(config.hidden_size, config.vocab_size)
+        
+        self.is_wav2vec_freeze = False
+        
+        # Initialize weights and apply final processing
+        self.post_init()
+
+    def freeze_feature_extractor(self):
+        """
+        Calling this function will disable the gradient computation for the feature encoder so that its parameter will
+        not be updated during training.
+        """
+        warnings.warn(
+            "The method `freeze_feature_extractor` is deprecated and will be removed in Transformers v5."
+            "Please use the equivalent `freeze_feature_encoder` method instead.",
+            FutureWarning,
+        )
+        self.freeze_feature_encoder()
+
+    def freeze_feature_encoder(self):
+        """
+        Calling this function will disable the gradient computation for the feature encoder so that its parameter will
+        not be updated during training.
+        """
+        self.wav2vec2.feature_extractor._freeze_parameters()
+    
+    def freeze_wav2vec(self, is_freeze=True):
+        """
+        Calling this function will disable the gradient computation for the feature extractor so that its parameter
+        will not be updated during training.
+        """
+        if is_freeze:
+            self.is_wav2vec_freeze = True
+            for param in self.wav2vec2.parameters():
+                param.requires_grad = False
+        else:
+            self.is_wav2vec_freeze = False
+            for param in self.wav2vec2.parameters():
+                param.requires_grad = True
+        self.freeze_feature_encoder()
+
+        model_total_params = sum(p.numel() for p in self.parameters())
+        model_total_params_trainable = sum(p.numel() for p in self.parameters() if p.requires_grad)
+        print("model_total_params: {}\nmodel_total_params_trainable: {}".format(model_total_params,
+                                                                                model_total_params_trainable))
+    
+    def forward(
+            self,
+            input_values,
+            attention_mask=None,
+            output_attentions=None,
+            output_hidden_states=None,
+            return_dict=None,
+            path=None,
+            length=None,
+            labels=None,
+    ):
+        r"""
+        labels (`torch.LongTensor` of shape `(batch_size, target_length)`, *optional*):
+            Labels for connectionist temporal classification. Note that `target_length` has to be smaller or equal to
+            the sequence length of the output logits. Indices are selected in `[-100, 0, ..., config.vocab_size - 1]`.
+            All labels set to `-100` are ignored (masked), the loss is only computed for labels in `[0, ...,
+            config.vocab_size - 1]`.
+        """
+
+        return_dict = return_dict if return_dict is not None else self.config.use_return_dict
+
+        outputs = self.wav2vec2(
+            input_values,
+            attention_mask=attention_mask,
+            output_attentions=output_attentions,
+            output_hidden_states=output_hidden_states,
+            return_dict=return_dict,
+        )
+
+        hidden_states = outputs[0]
+        hidden_states = self.dropout(hidden_states)
+
+        B, T, F = hidden_states.size()
+        hidden_states = hidden_states.view(B * T, F)
+
+        hidden_states = self.feature_transform(hidden_states)
+
+        hidden_states = hidden_states.view(B, T, F)
+
+        logits = self.lm_head(hidden_states)
+
+        loss = None
+        if labels is not None:
+
+            if labels.max() >= self.config.vocab_size:
+                raise ValueError(f"Label values must be <= vocab_size: {self.config.vocab_size}")
+
+            # retrieve loss input_lengths from attention_mask
+            attention_mask = (
+                attention_mask if attention_mask is not None else torch.ones_like(input_values, dtype=torch.long)
+            )
+            input_lengths = self._get_feat_extract_output_lengths(attention_mask.sum(-1)).to(torch.long)
+
+            # assuming that padded tokens are filled with -100
+            # when not being attended to
+            labels_mask = labels >= 0
+            target_lengths = labels_mask.sum(-1)
+            flattened_targets = labels.masked_select(labels_mask)
+
+            # ctc_loss doesn't support fp16
+            log_probs = nn.functional.log_softmax(logits, dim=-1, dtype=torch.float32).transpose(0, 1)
+
+            with torch.backends.cudnn.flags(enabled=False):
+                loss = nn.functional.ctc_loss(
+                    log_probs,
+                    flattened_targets,
+                    input_lengths,
+                    target_lengths,
+                    blank=self.config.pad_token_id,
+                    reduction=self.config.ctc_loss_reduction,
+                    zero_infinity=self.config.ctc_zero_infinity,
+                )
+
+        if not return_dict:
+            output = (logits,) + outputs[_HIDDEN_STATES_START_POSITION:]
+            return ((loss,) + output) if loss is not None else output
+
+        return CausalLMOutput(
+            loss=loss, logits=logits, hidden_states=outputs.hidden_states, attentions=outputs.attentions
+        )