import copy import os import re import uuid from typing import Dict, List, Optional, Union import numpy as np import PIL from PIL import Image import torch from transformers.feature_extraction_utils import BatchFeature from transformers.image_utils import ImageInput, load_image from transformers.processing_utils import ( AllKwargsForChatTemplate, ChatTemplateLoadKwargs, ProcessingKwargs, ProcessorMixin, Unpack, ) from transformers.tokenization_utils_base import AudioInput, TextInput from transformers.utils import ( is_torch_device, is_torch_dtype, logging, requires_backends, ) from transformers.utils.chat_template_utils import render_jinja_template from transformers.video_utils import VideoInput, VideoMetadata, load_video logger = logging.get_logger(__name__) class HCXBatchFeature(BatchFeature): def to(self, *args, **kwargs) -> "BatchFeature": """ Send all values to device by calling `v.to(*args, **kwargs)` (PyTorch only). This should support casting in different `dtypes` and sending the `BatchFeature` to a different `device`. Args: args (`Tuple`): Will be passed to the `to(...)` function of the tensors. kwargs (`Dict`, *optional*): Will be passed to the `to(...)` function of the tensors. To enable asynchronous data transfer, set the `non_blocking` flag in `kwargs` (defaults to `False`). Returns: [`BatchFeature`]: The same instance after modification. """ requires_backends(self, ["torch"]) import torch # noqa new_data = {} device = kwargs.get("device") non_blocking = kwargs.get("non_blocking", False) # Check if the args are a device or a dtype if device is None and len(args) > 0: # device should be always the first argument arg = args[0] if is_torch_dtype(arg): # The first argument is a dtype pass elif isinstance(arg, str) or is_torch_device(arg) or isinstance(arg, int): device = arg else: # it's something else raise ValueError(f"Attempting to cast a BatchFeature to type {str(arg)}. This is not supported.") # We cast only floating point tensors to avoid issues with tokenizers casting `LongTensor` to `FloatTensor` for k, v in self.items(): # check if v is a floating point if isinstance(v, torch.Tensor) and torch.is_floating_point(v): # cast and send to device new_data[k] = v.to(*args, **kwargs) elif isinstance(v, torch.Tensor) and device is not None: new_data[k] = v.to(device=device, non_blocking=non_blocking) elif "pixel_values" in k: new_pixel_values_batch = [] for _v in v: pixel_values = [pixel_value.to(device=device, non_blocking=non_blocking) for pixel_value in _v] new_pixel_values_batch.append(pixel_values) new_data[k] = new_pixel_values_batch else: new_data[k] = v self.data = new_data return self class HCXProcessorKwargs(ProcessingKwargs, total=False): _defaults = { "text_kwargs": { "return_tensors": "pt", "calc_non_vision_query_lengths": False, }, "images_kwargs": {}, "audio_kwargs": {}, "videos_kwargs": { "max_image_cnt": 12, "max_num_grids": 9, }, } class HCXProcessor(ProcessorMixin): attributes = ["image_processor", "tokenizer"] valid_kwargs = ["chat_template"] image_processor_class = "AutoImageProcessor" tokenizer_class = ("GPT2Tokenizer", "GPT2TokenizerFast") def __init__(self, image_processor=None, tokenizer=None, chat_template=None, **kwargs): self.image_token = "<|dummy3|>" self.video_token = "<|_unuse_missing_100270|>" self.image_token_pattern = re.compile(r"<\|dummy3\|>") self.video_token_pattern = re.compile(r"<\|_unuse_missing_100270\|>") self.image_video_token_pattern = re.compile(r"<\|dummy3\|>|<\|_unuse_missing_100270\|>") self.image_token_id = ( tokenizer.image_token_id if getattr(tokenizer, "image_token_id", None) else tokenizer.convert_tokens_to_ids(self.image_token) ) self.video_token_id = ( tokenizer.video_token_id if getattr(tokenizer, "video_token_id", None) else tokenizer.convert_tokens_to_ids(self.video_token) ) super().__init__(image_processor, tokenizer, chat_template=chat_template) def apply_chat_template( self, conversation: Union[list[dict[str, str]], list[list[dict[str, str]]]], chat_template: Optional[str] = None, **kwargs: Unpack[AllKwargsForChatTemplate], ) -> str: """ Similar to the `apply_chat_template` method on tokenizers, this method applies a Jinja template to input conversations to turn them into a single tokenizable string. The input is expected to be in the following format, where each message content is a list consisting of text and optionally image or video inputs. One can also provide an image, video, URL or local path which will be used to form `pixel_values` when `return_dict=True`. If not provided, one will get only the formatted text, optionally tokenized text. conversation = [ { "role": "user", "content": [ {"type": "image", "image": "https://www.ilankelman.org/stopsigns/australia.jpg"}, {"type": "text", "text": "Please describe this image in detail."}, ], }, ] Args: conversation (`Union[List[Dict, [str, str]], List[List[Dict[str, str]]]]`): The conversation to format. chat_template (`Optional[str]`, *optional*): The Jinja template to use for formatting the conversation. If not provided, the tokenizer's chat template is used. """ if chat_template is None: if isinstance(self.chat_template, dict) and "default" in self.chat_template: chat_template = self.chat_template["default"] elif isinstance(self.chat_template, dict): raise ValueError( 'The processor has multiple chat templates but none of them are named "default". You need to specify' " which one to use by passing the `chat_template` argument. Available templates are: " f"{', '.join(self.chat_template.keys())}" ) elif self.chat_template is not None: chat_template = self.chat_template else: raise ValueError( "Cannot use apply_chat_template because this processor does not have a chat template." ) else: if isinstance(self.chat_template, dict) and chat_template in self.chat_template: # It's the name of a template, not a full template string chat_template = self.chat_template[chat_template] else: # It's a template string, render it directly chat_template = chat_template if kwargs.get("continue_final_message", False): if kwargs.get("add_generation_prompt", False): raise ValueError( "continue_final_message and add_generation_prompt are not compatible. Use continue_final_message when you want the model to continue the final message, and add_generation_prompt when you want to add a header that will prompt it to start a new assistant message instead." ) if kwargs.get("return_assistant_tokens_mask", False): raise ValueError("continue_final_message is not compatible with return_assistant_tokens_mask.") # Fill sets of kwargs that should be used by different parts of template processed_kwargs = { "mm_load_kwargs": {}, "template_kwargs": {}, } for kwarg_type in processed_kwargs: for key in AllKwargsForChatTemplate.__annotations__[kwarg_type].__annotations__.keys(): kwarg_type_defaults = AllKwargsForChatTemplate.__annotations__[kwarg_type] default_value = getattr(kwarg_type_defaults, key, None) value = kwargs.pop(key, default_value) if value is not None and not isinstance(value, dict): processed_kwargs[kwarg_type][key] = value # Pass unprocessed custom kwargs processed_kwargs["template_kwargs"].update(kwargs) if isinstance(conversation, (list, tuple)) and ( isinstance(conversation[0], (list, tuple)) or hasattr(conversation[0], "content") ): is_batched = True conversations = conversation else: is_batched = False conversations = [conversation] tokenize = processed_kwargs["template_kwargs"].pop("tokenize", False) return_dict = processed_kwargs["template_kwargs"].pop("return_dict", False) mm_load_kwargs = processed_kwargs["mm_load_kwargs"] if tokenize: batch_images, batch_videos = [], [] batch_audios = [] batch_video_metadata = [] for conversation in conversations: images, videos = [], [] video_metadata = [] for message in conversation: visuals = [content for content in message["content"] if content["type"] in ["image", "video"]] audio_fnames = [ content[key] for content in message["content"] for key in ["audio", "url", "path"] if key in content and content["type"] == "audio" ] image_fnames = [ vision_info[key] for vision_info in visuals for key in ["image", "url", "path", "base64"] if key in vision_info and vision_info["type"] == "image" ] video_fnames = [ vision_info[key] for vision_info in visuals for key in ["video", "url", "path"] if key in vision_info and vision_info["type"] == "video" ] for fname in image_fnames: images.append(load_image(fname)) # Audio models do not accept nested list of audios (yet!) so we construct a flat input audio list if not mm_load_kwargs["load_audio_from_video"]: for fname in audio_fnames: batch_audios.append(load_audio(fname, sampling_rate=mm_load_kwargs["sampling_rate"])) else: for fname in video_fnames: batch_audios.append(load_audio(fname, sampling_rate=mm_load_kwargs["sampling_rate"])) for fname in video_fnames: if isinstance(fname, (list, tuple)) and isinstance(fname[0], str): video = [np.array(load_image(image_fname)) for image_fname in fname] # create a 4D video because `load_video` always returns a 4D array video = np.stack(video) metadata = None logger.warning( "When loading the video from list of images, we cannot infer metadata such as `fps` or `duration`. " "If your model uses this metadata during processing, please load the whole video and let the model sample frames instead." ) else: # TODO: raushan, should be `self.video_processor.load_video_for_model` when API is added video, metadata = self._load_video_for_model( fname, num_frames=mm_load_kwargs.get("num_frames", None), fps=mm_load_kwargs.get("video_fps", None), backend=mm_load_kwargs["video_load_backend"], **kwargs, ) videos.append(video) video_metadata.append(metadata) # Currently all processors can accept nested list of batches, but not flat list of visuals # So we'll make a batched list of images and let the processor handle it if images: batch_images.append(images) if videos: batch_videos.append(videos) batch_video_metadata.append(video_metadata) # Process conversation with video/image information if needed. Then convert into a prompt using Jinja template conversations = self._process_messages_for_chat_template( conversations, batch_images=batch_images, batch_videos=batch_videos, batch_video_metadata=batch_video_metadata, **processed_kwargs["mm_load_kwargs"], ) prompt, generation_indices = render_jinja_template( conversations=conversations, chat_template=chat_template, **processed_kwargs["template_kwargs"], # different flags such as `return_assistant_mask` **self.tokenizer.special_tokens_map, # tokenizer special tokens are used by some templates ) if not is_batched: prompt = prompt[0] if tokenize: # Tokenizer's `apply_chat_template` never adds special tokens when tokenizing # But processor's `apply_chat_template` didn't have an option to tokenize, so users had to format the prompt # and pass it to the processor. Users thus never worried about special tokens relying on processor handling # everything internally. The below line is to keep BC for that and be able to work with model that have # special tokens in the template (consistent with tokenizers). We dont want to raise warning, it will flood command line # without actionable solution for users single_prompt = prompt[0] if is_batched else prompt if self.tokenizer.bos_token is not None and single_prompt.startswith(self.tokenizer.bos_token): kwargs["add_special_tokens"] = False out = self( text=prompt, images=batch_images if batch_images else None, videos=batch_videos if batch_videos else None, audio=batch_audios if batch_audios else None, **kwargs, ) if return_dict: if processed_kwargs["template_kwargs"].get("return_assistant_tokens_mask", False): assistant_masks = [] input_ids = out["input_ids"] for i in range(len(input_ids)): current_mask = [0] * len(input_ids[i]) for assistant_start_char, assistant_end_char in generation_indices[i]: start_token = out.char_to_token(i, assistant_start_char) end_token = out.char_to_token(i, assistant_end_char - 1) if start_token is None: # start_token is out of bounds maybe due to truncation. break for token_id in range(start_token, end_token + 1 if end_token else len(input_ids[i])): current_mask[token_id] = 1 assistant_masks.append(current_mask) out["assistant_masks"] = assistant_masks out.convert_to_tensors(tensor_type=kwargs.get("return_tensors", None)) # vllm needs vision_query_lengths, but hf model doesn't need it del out["vision_query_lengths_images"] del out["vision_query_lengths_videos"] return out else: return out["input_ids"] def repeat_dummy_tokens(self, input_ids, target_token_id, vision_query_lengths): input_ids = input_ids.clone().detach() batch_indices, target_indices = torch.where(input_ids == target_token_id) batch_size = input_ids.shape[0] new_input_ids = [[] for _ in range(batch_size)] start_indices = [0 for _ in range(batch_size)] counter = [0 for _ in range(batch_size)] for batch_idx, target_idx in zip(batch_indices, target_indices): start_idx = start_indices[batch_idx] new_input_ids[batch_idx].append(input_ids[batch_idx][start_idx:target_idx]) query_length = vision_query_lengths[batch_idx][counter[batch_idx]] new_input_ids[batch_idx].append(input_ids[batch_idx][target_idx].repeat(query_length)) start_indices[batch_idx] = target_idx + 1 counter[batch_idx] += 1 for batch_idx in range(batch_size): start_idx = start_indices[batch_idx] new_input_ids[batch_idx].append(input_ids[batch_idx][start_idx:]) # append remaining tokens new_input_ids[batch_idx] = torch.cat(new_input_ids[batch_idx], dim=0) new_input_ids = torch.stack(new_input_ids) return new_input_ids def _load_video_for_model( self, video: str, num_frames: Optional[int] = None, fps: Optional[int] = None, backend: str = "opencv", **kwargs: Unpack[HCXProcessorKwargs], ) -> List[ImageInput]: """ Overrided function. Loads `video` to a List[PIL.Image] (llava style) Args: video (`str`): The video to convert to the numpy array format. Can be a link to video or local path. num_frames (`int`, *optional*): Number of frames to sample uniformly. If not passed, the whole video is loaded. fps (`int`, *optional*): Number of frames to sample per second. Should be passed only when `num_frames=None`. If not specified and `num_frames==None`, all frames are sampled. backend (`str`, *optional*, defaults to `"opencv"`): The backend to use when loading the video. Can be any of ["decord", "pyav", "opencv", "torchvision"]. Defaults to "opencv". Returns: Tuple[`np.array`, Dict]: A tuple containing: - List[PIL.Image] of frames in RGB. - Metadata dictionary. """ output_kwargs = self._merge_kwargs( HCXProcessorKwargs, tokenizer_init_kwargs=self.tokenizer.init_kwargs, **kwargs, ) logger.warning_once(f"num_frames control via argument is not supported yet. Ignored num_frames: {num_frames}.") logger.warning_once(f"fps control via argument is not supported yet. Ignored fps: {fps}.") logger.warning_once(f"backend control via argument is not supported yet. Ignored backend: {backend}.") # video_loaded, video_metadata = load_video( # video, backend="decord", num_frames=32 # ) # frame_interval = int(video_metadata.total_num_frames / 32) # time_interval = frame_interval / video_metadata.fps # video_metadata.time_interval = time_interval def _hcx_sample_indices_fn(metadata: VideoMetadata, num_frames=None, fps=None, **kwargs): max_num_grids = output_kwargs["videos_kwargs"]["max_num_grids"] max_image_cnt = output_kwargs["videos_kwargs"]["max_image_cnt"] frame_indices, time_interval = extract_frame_indices( metadata.duration, metadata.total_num_frames, metadata.fps, max_num_grids, max_image_cnt, default_interval=0.4, ) metadata.time_interval = time_interval return np.array(frame_indices) video_loaded, video_metadata = None, None for backend in ["decord", "pyav", "opencv", "torchvision"]: try: video_loaded, video_metadata = load_video( video, sample_indices_fn=_hcx_sample_indices_fn, backend=backend ) break except Exception as e: logger.error(f"Error loading video with {backend} backend: {e}") continue assert video_loaded is not None, "Failed to load video with any backend" return video_loaded, video_metadata def _process_messages_for_chat_template( self, conversation: List[List[Dict[str, str]]], batch_images: List[List[ImageInput]], batch_videos: List[List[VideoInput]], batch_video_metadata: List[List[Dict[str, any]]], **mm_load_kwargs: Unpack[ChatTemplateLoadKwargs], ): """ Overrided function. Used within `apply_chat_template` when a model has a special way to process conversation history. For example, video models might want to specify in the prompt the duration of video or which frame indices at which timestamps were sampled. This information cannot be accessed before the video is loaded. For most models it is a no-op, and must be overridden by model processors which require special processing. Args: conversation (`List[Dict, str, str]`): The conversation to process. Always comes in batched format. batch_images (`List[List[ImageInput]]`): Batch of images that were loaded from url/path defined in the conversation. The images are ordered in the same way as in the conversation. Comes in nested list format, one list of `PIL` images per batch. batch_videos (`List[List[ImageInput]]`): Batch of videos that were loaded from url/path defined in the conversation. The videos are ordered in the same way as in the conversation. Comes in nested list format, one list of `PIL.Image` per batch. batch_video_metadata (`List[List[Dict[[str, any]]]]`): Batch of metadata returned from loading videos. That includes video fps, duration and total number of framer in original video. Metadata are ordered in the same way as `batch_videos`. Comes in nested list format, one list of `Dict` per batch. """ is_video_in_conversation = False for batch_idx, messages in enumerate(conversation): is_video_in_messages = False is_image_in_messages = False for message in messages: for content in message["content"]: if content["type"] == "video": is_video_in_messages = True elif content["type"] == "image": is_image_in_messages = True if not is_video_in_messages: batch_videos.insert(batch_idx, []) batch_video_metadata.insert(batch_idx, []) if not is_image_in_messages: batch_images.insert(batch_idx, []) is_video_in_conversation = is_video_in_conversation or is_video_in_messages if not is_video_in_conversation: return conversation # conversation processing new_conversation = [] for batch_idx, messages in enumerate(conversation): video_counter = 0 new_messages = [] for message in messages: new_message = { "role": message["role"], "content": [], } for content in message["content"]: if content["type"] == "video": video = batch_videos[batch_idx][video_counter] video_meta = batch_video_metadata[batch_idx][video_counter] time_stamps = calc_timestamp_video_grids(video, video_meta.time_interval, max_grid_shape=(3, 3)) video_counter += 1 if "filename" in content: filename = content["filename"] else: filename = content["video"].split("/")[-1] if len(filename) > 50: filename = f"{uuid.uuid4().hex}.mp4" basename, ext = os.path.splitext(filename) if ext == "": ext = ".mp4" for frame_idx, time_stamp in enumerate(time_stamps): if frame_idx == len(video) - 1: # final_grid new_content = { "filename": f"{basename}-{frame_idx}{ext}", "video": content["video"], "type": "video", "video_time_stamp": time_stamp, "lens_keywords": content["lens_keywords"], "lens_local_keywords": content["lens_local_keywords"], "speech_to_text": content["speech_to_text"], "is_final_grid": True, } new_message["content"].append(new_content) else: new_content = { "filename": f"{basename}-{frame_idx}{ext}", "video": content["video"], "type": "video", "video_time_stamp": time_stamp, } new_message["content"].append(new_content) else: new_message["content"].append(copy.deepcopy(content)) new_messages.append(new_message) new_conversation.append(new_messages) return new_conversation def __call__( self, text: TextInput = None, images: List[List[ImageInput]] = None, videos: List[List[VideoInput]] = None, audio: AudioInput = None, **kwargs: Unpack[HCXProcessorKwargs], ): output_kwargs = self._merge_kwargs( HCXProcessorKwargs, tokenizer_init_kwargs=self.tokenizer.init_kwargs, **kwargs, ) # prepare model inputs mm_inputs = { "pixel_values_images": [], "image_sizes_images": [], "vision_query_lengths_images": [], "pixel_values_videos": [], # "image_sizes_videos": [], "vision_query_lengths_videos": [], } calc_non_vision_query_lengths = output_kwargs["text_kwargs"].pop("calc_non_vision_query_lengths") if calc_non_vision_query_lengths: mm_inputs["non_vision_query_lengths"] = [] # video processing if videos is not None: vit_input_size = self.image_processor.crop_size["width"] video_kwargs = copy.deepcopy(output_kwargs["videos_kwargs"]) for videos_in_single_conversation in videos: pixel_values_videos = [] vision_query_lengths_videos = [] for video_frames in videos_in_single_conversation: if len(video_frames) == 0: mm_inputs["pixel_values_videos"].append([]) mm_inputs["vision_query_lengths_videos"].append([]) continue video_frames_combined = combine_frames_into_images( video_frames, max_grid_shape=(3, 3), vit_input_size=vit_input_size ) video_kwargs["is_video"] = True video_kwargs["return_tensors"] = None frames_processed = self.image_processor(images=video_frames_combined, **video_kwargs) sizes = [(size["width"], size["height"]) for size in frames_processed["image_sizes"]] pixel_values_videos.extend(frames_processed["pixel_values"]) vision_query_lengths_videos.extend(frames_processed["vision_query_lengths"]) mm_inputs["pixel_values_videos"].append(pixel_values_videos) mm_inputs["vision_query_lengths_videos"].append(vision_query_lengths_videos) # image processing if images is not None: image_kwargs = copy.deepcopy(output_kwargs["images_kwargs"]) image_kwargs["is_video"] = False image_kwargs["return_tensors"] = None for images_in_single_conversation in images: if isinstance(images_in_single_conversation, PIL.Image.Image): # single item to batch images_in_single_conversation = [images_in_single_conversation, ] if len(images_in_single_conversation) == 0: mm_inputs["pixel_values_images"].append([]) mm_inputs["image_sizes_images"].append([]) mm_inputs["vision_query_lengths_images"].append([]) continue images_processed = self.image_processor(images=images_in_single_conversation, **image_kwargs) sizes = [(size["width"], size["height"]) for size in images_processed["image_sizes"]] mm_inputs["pixel_values_images"].append(images_processed["pixel_values"]) mm_inputs["image_sizes_images"].append(sizes) mm_inputs["vision_query_lengths_images"].append(images_processed["vision_query_lengths"]) # text processing def _create_replacer(_target_token, _replacements): _iterator = iter(_replacements) def _replacer(match_obj): # return self.image_token num_query_tokens = next(_iterator) return "".join([_target_token for _ in range(num_query_tokens)]) return _replacer text_inputs = {} if text is not None: if not isinstance(text, list): text = [text] if images is not None: new_texts = [] for batch_idx, text_in_single_conversation in enumerate(text): new_text = self.image_token_pattern.sub( _create_replacer(self.image_token, mm_inputs["vision_query_lengths_images"][batch_idx]), text_in_single_conversation, ) new_texts.append(new_text) text = new_texts if videos is not None: new_texts = [] for batch_idx, text_in_single_conversation in enumerate(text): new_text = self.video_token_pattern.sub( _create_replacer(self.video_token, mm_inputs["vision_query_lengths_videos"][batch_idx]), text_in_single_conversation, ) new_texts.append(new_text) text = new_texts text_inputs = self.tokenizer(text, **output_kwargs["text_kwargs"]) # audio processing if audio is not None: raise NotImplementedError("Audio processing is not supported yet.") return HCXBatchFeature(data={**text_inputs, **mm_inputs}) def decode(self, *args, **kwargs): """ This method forwards all its arguments to Siglip2Tokenizer's [`~PreTrainedTokenizer.decode`]. Please refer to the docstring of this method for more information. """ return self.tokenizer.decode(*args, **kwargs) def batch_decode(self, *args, **kwargs): """ This method forwards all its arguments to Siglip2Tokenizer's [`~PreTrainedTokenizer.batch_decode`]. Please refer to the docstring of this method for more information. """ return self.tokenizer.batch_decode(*args, **kwargs) def post_process_image_text_to_text( self, generated_outputs, skip_special_tokens=True, clean_up_tokenization_spaces=False, **kwargs ): """ Post-process the output of the model to decode the text. Args: generated_outputs (`torch.Tensor` or `np.ndarray`): The output of the model `generate` function. The output is expected to be a tensor of shape `(batch_size, sequence_length)` or `(sequence_length,)`. skip_special_tokens (`bool`, *optional*, defaults to `True`): Whether or not to remove special tokens in the output. Argument passed to the tokenizer's `batch_decode` method. Clean_up_tokenization_spaces (`bool`, *optional*, defaults to `False`): Whether or not to clean up the tokenization spaces. Argument passed to the tokenizer's `batch_decode` method. **kwargs: Additional arguments to be passed to the tokenizer's `batch_decode method`. Returns: `List[str]`: The decoded text. """ return self.tokenizer.batch_decode( generated_outputs, skip_special_tokens=skip_special_tokens, clean_up_tokenization_spaces=clean_up_tokenization_spaces, **kwargs, ) @property def model_input_names(self): tokenizer_input_names = self.tokenizer.model_input_names image_processor_input_names = self.image_processor.model_input_names names_from_processor = list(dict.fromkeys(tokenizer_input_names + image_processor_input_names)) return names_from_processor + [] def extract_frame_indices(play_time, total_frames, fps, max_num_grids, max_image_cnt, default_interval=0.4): """ Extracts specific frame indices from a video based on duration, frame count, and sampling strategy. The function determines which frames to extract given the video duration (`play_time`), total frame count, and frame rate. It samples frames at regular intervals (default: 0.4s), but if the number of frames exceeds the limit defined by `max_num_grids * max_image_cnt`, it performs uniform sampling to stay within that limit. Args: play_time (float): Total play time of the video in seconds. total_frames (int): Total number of frames in the video. fps (float): Frames per second of the video. max_num_grids (int): Maximum number of grids to display. max_image_cnt (int): Maximum number of images per grid. default_interval (float, optional): Interval in seconds between frame samples. Defaults to 0.4. Returns: Tuple: frame_indices (List[int]): A list of selected frame indices. time_interval (float): Time interval between selected frames (in seconds). """ # Calculate how many frames to extract with the default interval default_frame_count = int(play_time / default_interval) # Maximum frames allowed based on max_num_grids and max_image_cnt max_frames_allowed = max_num_grids * max_image_cnt # Determine whether we can use the default interval or need uniform sampling if default_frame_count <= max_frames_allowed: # Default interval is sufficient, extract frames every 0.4 seconds frame_interval = int(total_frames / default_frame_count) else: # Use uniform sampling to fit within max_frames_allowed frame_interval = int(total_frames / max_frames_allowed) # Extract frame indices at the calculated interval selected_indices = list(range(0, total_frames, frame_interval)) time_interval = frame_interval / fps # Ensure the number of selected indices does not exceed max_frames_allowed return selected_indices[:max_frames_allowed], time_interval def calc_timestamp_video_grids(frames, time_interval, max_grid_shape=(3, 3)): """ Calculates the time range labels for each grid in a video. Args: frames (List[PIL.Image.Image]): A list of frames extracted from a video. time_interval (float): Time interval (in seconds) between consecutive frames. max_grid_shape (Tuple[int, int], optional): The maximum grid shape as (rows, cols). Defaults to (3, 3). vit_input_size (int, optional): The target size (height and width) for the Vision Transformer input. Defaults to 378. Returns: Tuple: image_time_stamps (List[str]): A list of time span labels for each combined image, e.g., ["0.00s~1.50s", "1.50s~3.00s", ...]. """ max_num_grids = max_grid_shape[0] * max_grid_shape[1] # assert ( # max_grid_shape[1] == 1 # ), f"For video processing, decided to concatenate frames horizontally into a wide image." # Calculate the number of canvases needed. num_frames = len(frames) num_canvases = num_frames // max_num_grids leftover_frames = num_frames % max_num_grids time_stamp = 0 # second image_time_stamps = [] for canvas_idx in range(num_canvases): # Determine the frames to fill in the current canvas. start_idx = canvas_idx * max_num_grids end_idx = min(start_idx + max_num_grids, num_frames) # Append the current canvas to the result list. frame_cnt = end_idx - start_idx image_time_stamps.append(f"{time_stamp:.2f}s~{time_stamp + frame_cnt * time_interval:.2f}s") time_stamp += frame_cnt * time_interval if leftover_frames > 0: # Add the current canvas to the list of combined images. frame_cnt = leftover_frames image_time_stamps.append(f"{time_stamp:.2f}s~{time_stamp + frame_cnt * time_interval:.2f}s") time_stamp += frame_cnt * time_interval return image_time_stamps def combine_frames_into_images(frames, max_grid_shape=(3, 3), vit_input_size=378): """ Combines a sequence of video frames into grid-based images and generates corresponding time range labels. Frames are grouped and arranged into a grid (e.g., 3x3) such that each combined image contains up to `max_grid_shape[0] * max_grid_shape[1]` frames. Each combined image is resized to the given ViT input size. Args: frames (NDArray): (num_frames, H, W, C) shape. A list of frames extracted from a video. time_interval (float): Time interval (in seconds) between consecutive frames. max_grid_shape (Tuple[int, int], optional): The maximum grid shape as (rows, cols). Defaults to (3, 3). vit_input_size (int, optional): The target size (height and width) for the Vision Transformer input. Defaults to 378. Returns: Tuple: image_list (List[PIL.Image.Image]): A list of grid-combined images. """ max_num_grids = max_grid_shape[0] * max_grid_shape[1] # assert ( # max_grid_shape[1] == 1 # ), f"For video processing, decided to concatenate frames horizontally into a wide image." # List to store the resulting combined images. image_list = [] # Calculate the number of canvases needed. num_frames = len(frames) num_canvases = num_frames // max_num_grids leftover_frames = num_frames % max_num_grids # change frames (4d numpy tensor) to List[PIL.Image.Image] frames = [Image.fromarray(frame) for frame in frames] for canvas_idx in range(num_canvases): # Initialize the current canvas. combined_image = Image.new( "RGB", (vit_input_size * max_grid_shape[0], vit_input_size * max_grid_shape[1]), color=(0, 0, 0) ) # Determine the frames to fill in the current canvas. start_idx = canvas_idx * max_num_grids end_idx = min(start_idx + max_num_grids, num_frames) for idx in range(start_idx, end_idx): img = frames[idx] # Resize each frame to a square shape. img_resized = img.resize((vit_input_size, vit_input_size)) # Calculate the (row, column) position to place the frame within the grid layout. local_idx = idx - start_idx x_offset = (local_idx % max_grid_shape[0]) * vit_input_size y_offset = (local_idx // max_grid_shape[0]) * vit_input_size # Calculate the position to place the frame in the grid. combined_image.paste(img_resized, (x_offset, y_offset)) # Append the current canvas to the result list. image_list.append(combined_image) if leftover_frames > 0: # canvas_idx might be undefined; default to 0 if not previously assigned to avoid "referenced before assignment" error. canvas_idx = num_canvases # Add the remaining frames to the final canvas. # combined_image = Image.new("RGB", (vit_input_size * leftover_frames, vit_input_size * 1), color=(0, 0, 0)) # hsk combined_image = Image.new( "RGB", (vit_input_size * max_grid_shape[0], vit_input_size * max_grid_shape[1]), color=(0, 0, 0) ) for idx in range(leftover_frames): img = frames[num_canvases * max_num_grids + idx] # Resize the frame to a square (equal width and height). img_resized = img.resize((vit_input_size, vit_input_size)) # Calculate the (row, column) position to place the frame within the grid layout. # x_offset = (idx % leftover_frames) * vit_input_size # hsk # y_offset = (idx // leftover_frames) * vit_input_size # hsk x_offset = (idx % max_grid_shape[0]) * vit_input_size y_offset = (idx // max_grid_shape[0]) * vit_input_size # Calculate the position to place the frame within the grid layout. combined_image.paste(img_resized, (x_offset, y_offset)) # Add the current canvas to the list of combined images. image_list.append(combined_image) return image_list