def forward(
        self,
        input_ids: Optional[torch.Tensor] = None,
        attention_mask: Optional[torch.Tensor] = None,
        position_ids: Optional[torch.Tensor] = None,
        pixel_values: Optional[torch.Tensor] = None,
        head_mask: Optional[torch.Tensor] = None,
        inputs_embeds: Optional[torch.Tensor] = None,
        labels: Optional[torch.Tensor] = None,
        past_key_values: Optional[List[torch.Tensor]] = None,
        use_cache: Optional[bool] = None,
        output_attentions: Optional[bool] = None,
        output_hidden_states: Optional[bool] = None,
        return_dict: Optional[bool] = None,
    ) -> Union[Tuple[torch.Tensor], CausalLMOutputWithPast]:
        r"""
        labels (`torch.LongTensor` of shape `(batch_size, sequence_length)`, *optional*):
            Labels for computing the left-to-right language modeling loss (next word prediction). Indices should be in
            `[-100, 0, ..., config.vocab_size]` (see `input_ids` docstring) Tokens with indices set to `-100` are
            ignored (masked), the loss is only computed for the tokens with labels n `[0, ..., config.vocab_size]`
        past_key_values (`tuple(tuple(torch.FloatTensor))` of length `config.n_layers` with each tuple having 4 tensors of shape `(batch_size, num_heads, sequence_length - 1, embed_size_per_head)`):
            Contains precomputed key and value hidden states of the attention blocks. Can be used to speed up decoding.

            If `past_key_values` are used, the user can optionally input only the last `decoder_input_ids` (those that
            don't have their past key value states given to this model) of shape `(batch_size, 1)` instead of all
            `decoder_input_ids` of shape `(batch_size, sequence_length)`.
        use_cache (`bool`, *optional*):
            If set to `True`, `past_key_values` key value states are returned and can be used to speed up decoding (see
            `past_key_values`).

        Returns:

        Examples:

        Image captioning example:

        ```python
        >>> from transformers import AutoProcessor, AutoModelForCausalLM
        >>> import requests
        >>> from PIL import Image

        >>> processor = AutoProcessor.from_pretrained("microsoft/git-base-coco")
        >>> model = AutoModelForCausalLM.from_pretrained("microsoft/git-base-coco")

        >>> url = "http://images.cocodataset.org/val2017/000000039769.jpg"
        >>> image = Image.open(requests.get(url, stream=True).raw)

        >>> pixel_values = processor(images=image, return_tensors="pt").pixel_values

        >>> generated_ids = model.generate(pixel_values=pixel_values, max_length=50)
        >>> generated_caption = processor.batch_decode(generated_ids, skip_special_tokens=True)[0]
        >>> print(generated_caption)
        two cats sleeping on a pink blanket next to remotes.
        ```

        Visual question answering (VQA) example:

        ```python
        >>> from transformers import AutoProcessor, AutoModelForCausalLM
        >>> from huggingface_hub import hf_hub_download
        >>> from PIL import Image

        >>> processor = AutoProcessor.from_pretrained("microsoft/git-base-textvqa")
        >>> model = AutoModelForCausalLM.from_pretrained("microsoft/git-base-textvqa")

        >>> file_path = hf_hub_download(repo_id="nielsr/textvqa-sample", filename="bus.png", repo_type="dataset")
        >>> image = Image.open(file_path).convert("RGB")

        >>> pixel_values = processor(images=image, return_tensors="pt").pixel_values

        >>> question = "what does the front of the bus say at the top?"

        >>> input_ids = processor(text=question, add_special_tokens=False).input_ids
        >>> input_ids = [processor.tokenizer.cls_token_id] + input_ids
        >>> input_ids = torch.tensor(input_ids).unsqueeze(0)

        >>> generated_ids = model.generate(pixel_values=pixel_values, input_ids=input_ids, max_length=50)
        >>> print(processor.batch_decode(generated_ids, skip_special_tokens=True))
        ['what does the front of the bus say at the top? special']
        ```

        Video captioning example:

        ```python
        >>> import av
        >>> import numpy as np
        >>> from PIL import Image
        >>> from huggingface_hub import hf_hub_download
        >>> from transformers import AutoProcessor, AutoModelForCausalLM

        >>> processor = AutoProcessor.from_pretrained("microsoft/git-base-vatex")
        >>> model = AutoModelForCausalLM.from_pretrained("microsoft/git-base-vatex")

        >>> # set seed for reproducability
        >>> np.random.seed(45)


        >>> def read_video_pyav(container, indices):
        ...     '''
        ...     Decode the video with PyAV decoder.
        ...     Args:
        ...         container (`av.container.input.InputContainer`): PyAV container.
        ...         indices (`List[int]`): List of frame indices to decode.
        ...     Returns:
        ...         result (np.ndarray): np array of decoded frames of shape (num_frames, height, width, 3).
        ...     '''
        ...     frames = []
        ...     container.seek(0)
        ...     start_index = indices[0]
        ...     end_index = indices[-1]
        ...     for i, frame in enumerate(container.decode(video=0)):
        ...         if i > end_index:
        ...             break
        ...         if i >= start_index and i in indices:
        ...             frames.append(frame)
        ...     return np.stack([x.to_ndarray(format="rgb24") for x in frames])


        >>> def sample_frame_indices(clip_len, frame_sample_rate, seg_len):
        ...     '''
        ...     Sample a given number of frame indices from the video.
        ...     Args:
        ...         clip_len (`int`): Total number of frames to sample.
        ...         frame_sample_rate (`int`): Sample every n-th frame.
        ...         seg_len (`int`): Maximum allowed index of sample's last frame.
        ...     Returns:
        ...         indices (`List[int]`): List of sampled frame indices
        ...     '''
        ...     converted_len = int(clip_len * frame_sample_rate)
        ...     end_idx = np.random.randint(converted_len, seg_len)
        ...     start_idx = end_idx - converted_len
        ...     indices = np.linspace(start_idx, end_idx, num=clip_len)
        ...     indices = np.clip(indices, start_idx, end_idx - 1).astype(np.int64)
        ...     return indices


        >>> # load video
        >>> file_path = hf_hub_download(
        ...     repo_id="nielsr/video-demo", filename="eating_spaghetti.mp4", repo_type="dataset"
        ... )
        >>> container = av.open(file_path)

        >>> # sample frames
        >>> num_frames = model.config.num_image_with_embedding
        >>> indices = sample_frame_indices(
        ...     clip_len=num_frames, frame_sample_rate=4, seg_len=container.streams.video[0].frames
        ... )
        >>> frames = read_video_pyav(container, indices)

        >>> pixel_values = processor(images=list(frames), return_tensors="pt").pixel_values

        >>> generated_ids = model.generate(pixel_values=pixel_values, max_length=50)

        >>> print("Generated caption:", processor.batch_decode(generated_ids, skip_special_tokens=True))
        Generated caption: ['a woman is sitting at a table and she is talking about the food she is holding.']
        ```
        """
        return_dict = return_dict if return_dict is not None else self.config.use_return_dict
        if labels is not None:
            use_cache = False

        outputs = self.git(
            input_ids,
            attention_mask=attention_mask,
            position_ids=position_ids,
            pixel_values=pixel_values,
            head_mask=head_mask,
            inputs_embeds=inputs_embeds,
            past_key_values=past_key_values,
            use_cache=use_cache,
            output_attentions=output_attentions,
            output_hidden_states=output_hidden_states,
            return_dict=return_dict,
        )

        sequence_output = outputs[0]
        logits = self.output(sequence_output)

        loss = None
        if labels is not None:
            # we are doing next-token prediction; shift prediction scores and input ids by one
            num_image_tokens = self.git.encoder.layer[0].attention.self.image_patch_tokens
            shifted_logits = logits[:, num_image_tokens:-1, :].contiguous()
            labels = labels[:, 1:].contiguous()
            loss_fct = CrossEntropyLoss()
            loss = loss_fct(shifted_logits.view(-1, self.config.vocab_size), labels.view(-1))

        if not return_dict:
            output = (logits,) + outputs[1:]
            return ((loss,) + output) if loss is not None else output

        return CausalLMOutputWithPast(
            loss=loss,
            logits=logits,
            past_key_values=outputs.past_key_values,
            hidden_states=outputs.hidden_states,
            attentions=outputs.attentions,
        )

        labels (`torch.LongTensor` of shape `(batch_size, sequence_length)`, *optional*):
            Labels for computing the left-to-right language modeling loss (next word prediction). Indices should be in
            `[-100, 0, ..., config.vocab_size]` (see `input_ids` docstring) Tokens with indices set to `-100` are
            ignored (masked), the loss is only computed for the tokens with labels n `[0, ..., config.vocab_size]`
        past_key_values (`tuple(tuple(torch.FloatTensor))` of length `config.n_layers` with each tuple having 4 tensors of shape `(batch_size, num_heads, sequence_length - 1, embed_size_per_head)`):
            Contains precomputed key and value hidden states of the attention blocks. Can be used to speed up decoding.

            If `past_key_values` are used, the user can optionally input only the last `decoder_input_ids` (those that
            don't have their past key value states given to this model) of shape `(batch_size, 1)` instead of all
            `decoder_input_ids` of shape `(batch_size, sequence_length)`.
        use_cache (`bool`, *optional*):
            If set to `True`, `past_key_values` key value states are returned and can be used to speed up decoding (see
            `past_key_values`).

        Returns:

        Examples:

        Image captioning example:

        ```python
        >>> from transformers import AutoProcessor, AutoModelForCausalLM
        >>> import requests
        >>> from PIL import Image

        >>> processor = AutoProcessor.from_pretrained("microsoft/git-base-coco")
        >>> model = AutoModelForCausalLM.from_pretrained("microsoft/git-base-coco")

        >>> url = "http://images.cocodataset.org/val2017/000000039769.jpg"
        >>> image = Image.open(requests.get(url, stream=True).raw)

        >>> pixel_values = processor(images=image, return_tensors="pt").pixel_values

        >>> generated_ids = model.generate(pixel_values=pixel_values, max_length=50)
        >>> generated_caption = processor.batch_decode(generated_ids, skip_special_tokens=True)[0]
        >>> print(generated_caption)
        two cats sleeping on a pink blanket next to remotes.
        ```

        Visual question answering (VQA) example:

        ```python
        >>> from transformers import AutoProcessor, AutoModelForCausalLM
        >>> from huggingface_hub import hf_hub_download
        >>> from PIL import Image

        >>> processor = AutoProcessor.from_pretrained("microsoft/git-base-textvqa")
        >>> model = AutoModelForCausalLM.from_pretrained("microsoft/git-base-textvqa")

        >>> file_path = hf_hub_download(repo_id="nielsr/textvqa-sample", filename="bus.png", repo_type="dataset")
        >>> image = Image.open(file_path).convert("RGB")

        >>> pixel_values = processor(images=image, return_tensors="pt").pixel_values

        >>> question = "what does the front of the bus say at the top?"

        >>> input_ids = processor(text=question, add_special_tokens=False).input_ids
        >>> input_ids = [processor.tokenizer.cls_token_id] + input_ids
        >>> input_ids = torch.tensor(input_ids).unsqueeze(0)

        >>> generated_ids = model.generate(pixel_values=pixel_values, input_ids=input_ids, max_length=50)
        >>> print(processor.batch_decode(generated_ids, skip_special_tokens=True))
        ['what does the front of the bus say at the top? special']
        ```

        Video captioning example:

        ```python
        >>> import av
        >>> import numpy as np
        >>> from PIL import Image
        >>> from huggingface_hub import hf_hub_download
        >>> from transformers import AutoProcessor, AutoModelForCausalLM

        >>> processor = AutoProcessor.from_pretrained("microsoft/git-base-vatex")
        >>> model = AutoModelForCausalLM.from_pretrained("microsoft/git-base-vatex")

        >>> # set seed for reproducability
        >>> np.random.seed(45)


        >>> def read_video_pyav(container, indices):
        ...     '''
        ...     Decode the video with PyAV decoder.
        ...     Args:
        ...         container (`av.container.input.InputContainer`): PyAV container.
        ...         indices (`List[int]`): List of frame indices to decode.
        ...     Returns:
        ...         result (np.ndarray): np array of decoded frames of shape (num_frames, height, width, 3).
        ...     '''
        ...     frames = []
        ...     container.seek(0)
        ...     start_index = indices[0]
        ...     end_index = indices[-1]
        ...     for i, frame in enumerate(container.decode(video=0)):
        ...         if i > end_index:
        ...             break
        ...         if i >= start_index and i in indices:
        ...             frames.append(frame)
        ...     return np.stack([x.to_ndarray(format="rgb24") for x in frames])


        >>> def sample_frame_indices(clip_len, frame_sample_rate, seg_len):
        ...     '''
        ...     Sample a given number of frame indices from the video.
        ...     Args:
        ...         clip_len (`int`): Total number of frames to sample.
        ...         frame_sample_rate (`int`): Sample every n-th frame.
        ...         seg_len (`int`): Maximum allowed index of sample's last frame.
        ...     Returns:
        ...         indices (`List[int]`): List of sampled frame indices
        ...     '''
        ...     converted_len = int(clip_len * frame_sample_rate)
        ...     end_idx = np.random.randint(converted_len, seg_len)
        ...     start_idx = end_idx - converted_len
        ...     indices = np.linspace(start_idx, end_idx, num=clip_len)
        ...     indices = np.clip(indices, start_idx, end_idx - 1).astype(np.int64)
        ...     return indices


        >>> # load video
        >>> file_path = hf_hub_download(
        ...     repo_id="nielsr/video-demo", filename="eating_spaghetti.mp4", repo_type="dataset"
        ... )
        >>> container = av.open(file_path)

        >>> # sample frames
        >>> num_frames = model.config.num_image_with_embedding
        >>> indices = sample_frame_indices(
        ...     clip_len=num_frames, frame_sample_rate=4, seg_len=container.streams.video[0].frames
        ... )
        >>> frames = read_video_pyav(container, indices)

        >>> pixel_values = processor(images=list(frames), return_tensors="pt").pixel_values

        >>> generated_ids = model.generate(pixel_values=pixel_values, max_length=50)

        >>> print("Generated caption:", processor.batch_decode(generated_ids, skip_special_tokens=True))
        Generated caption: ['a woman is sitting at a table and she is talking about the food she is holding.']
        ```
        
dpkd/transformers/src/transformers/models/git/modeling_git.py