import argparse import os import random from datetime import datetime from pathlib import Path from diffusers.utils import logging from typing import Optional, List, Union import imageio import numpy as np import torch from PIL import Image from transformers import ( T5EncoderModel, T5Tokenizer, AutoModelForCausalLM, AutoProcessor, AutoTokenizer, ) from ltx_video.models.autoencoders.causal_video_autoencoder import ( CausalVideoAutoencoder, ) from ltx_video.models.transformers.symmetric_patchifier import SymmetricPatchifier from ltx_video.models.transformers.transformer3d import Transformer3DModel from ltx_video.pipelines.pipeline_ltx_video import ConditioningItem, LTXVideoPipeline from ltx_video.schedulers.rf import RectifiedFlowScheduler from ltx_video.utils.skip_layer_strategy import SkipLayerStrategy MAX_HEIGHT = 720 MAX_WIDTH = 1280 MAX_NUM_FRAMES = 257 logger = logging.get_logger("LTX-Video") def get_total_gpu_memory(): if torch.cuda.is_available(): total_memory = torch.cuda.get_device_properties(0).total_memory / (1024**3) return total_memory return 0 def get_device(): if torch.cuda.is_available(): return "cuda" elif torch.backends.mps.is_available(): return "mps" return "cpu" def load_image_to_tensor_with_resize_and_crop( image_input: Union[str, Image.Image], target_height: int = 512, target_width: int = 768, ) -> torch.Tensor: """Load and process an image into a tensor. Args: image_input: Either a file path (str) or a PIL Image object target_height: Desired height of output tensor target_width: Desired width of output tensor """ if isinstance(image_input, str): image = Image.open(image_input).convert("RGB") elif isinstance(image_input, Image.Image): image = image_input else: raise ValueError("image_input must be either a file path or a PIL Image object") input_width, input_height = image.size aspect_ratio_target = target_width / target_height aspect_ratio_frame = input_width / input_height if aspect_ratio_frame > aspect_ratio_target: new_width = int(input_height * aspect_ratio_target) new_height = input_height x_start = (input_width - new_width) // 2 y_start = 0 else: new_width = input_width new_height = int(input_width / aspect_ratio_target) x_start = 0 y_start = (input_height - new_height) // 2 image = image.crop((x_start, y_start, x_start + new_width, y_start + new_height)) image = image.resize((target_width, target_height)) frame_tensor = torch.tensor(np.array(image)).permute(2, 0, 1).float() frame_tensor = (frame_tensor / 127.5) - 1.0 # Create 5D tensor: (batch_size=1, channels=3, num_frames=1, height, width) return frame_tensor.unsqueeze(0).unsqueeze(2) def calculate_padding( source_height: int, source_width: int, target_height: int, target_width: int ) -> tuple[int, int, int, int]: # Calculate total padding needed pad_height = target_height - source_height pad_width = target_width - source_width # Calculate padding for each side pad_top = pad_height // 2 pad_bottom = pad_height - pad_top # Handles odd padding pad_left = pad_width // 2 pad_right = pad_width - pad_left # Handles odd padding # Return padded tensor # Padding format is (left, right, top, bottom) padding = (pad_left, pad_right, pad_top, pad_bottom) return padding def convert_prompt_to_filename(text: str, max_len: int = 20) -> str: # Remove non-letters and convert to lowercase clean_text = "".join( char.lower() for char in text if char.isalpha() or char.isspace() ) # Split into words words = clean_text.split() # Build result string keeping track of length result = [] current_length = 0 for word in words: # Add word length plus 1 for underscore (except for first word) new_length = current_length + len(word) if new_length <= max_len: result.append(word) current_length += len(word) else: break return "-".join(result) # Generate output video name def get_unique_filename( base: str, ext: str, prompt: str, seed: int, resolution: tuple[int, int, int], dir: Path, endswith=None, index_range=1000, ) -> Path: base_filename = f"{base}_{convert_prompt_to_filename(prompt, max_len=30)}_{seed}_{resolution[0]}x{resolution[1]}x{resolution[2]}" for i in range(index_range): filename = dir / f"{base_filename}_{i}{endswith if endswith else ''}{ext}" if not os.path.exists(filename): return filename raise FileExistsError( f"Could not find a unique filename after {index_range} attempts." ) def seed_everething(seed: int): random.seed(seed) np.random.seed(seed) torch.manual_seed(seed) if torch.cuda.is_available(): torch.cuda.manual_seed(seed) if torch.backends.mps.is_available(): torch.mps.manual_seed(seed) def main(): parser = argparse.ArgumentParser( description="Load models from separate directories and run the pipeline." ) # Directories parser.add_argument( "--ckpt_path", type=str, required=True, help="Path to a safetensors file that contains all model parts.", ) parser.add_argument( "--output_path", type=str, default=None, help="Path to the folder to save output video, if None will save in outputs/ directory.", ) parser.add_argument("--seed", type=int, default="171198") # Pipeline parameters parser.add_argument( "--num_inference_steps", type=int, default=40, help="Number of inference steps" ) parser.add_argument( "--num_images_per_prompt", type=int, default=1, help="Number of images per prompt", ) parser.add_argument( "--guidance_scale", type=float, default=3, help="Guidance scale.", ) parser.add_argument( "--stg_scale", type=float, default=1, help="Spatiotemporal guidance scale. 0 to disable STG.", ) parser.add_argument( "--stg_rescale", type=float, default=0.7, help="Spatiotemporal guidance rescaling scale. 1 to disable rescale.", ) parser.add_argument( "--stg_mode", type=str, default="attention_values", help="Spatiotemporal guidance mode. " "It can be one of 'attention_values' (default), 'attension_skip', 'residual', or 'transformer_block'.", ) parser.add_argument( "--stg_skip_layers", type=str, default="19", help="Layers to block for spatiotemporal guidance. Comma separated list of integers.", ) parser.add_argument( "--image_cond_noise_scale", type=float, default=0.15, help="Amount of noise to add to the conditioned image", ) parser.add_argument( "--height", type=int, default=480, help="Height of the output video frames. Optional if an input image provided.", ) parser.add_argument( "--width", type=int, default=704, help="Width of the output video frames. If None will infer from input image.", ) parser.add_argument( "--num_frames", type=int, default=121, help="Number of frames to generate in the output video", ) parser.add_argument( "--frame_rate", type=int, default=25, help="Frame rate for the output video" ) parser.add_argument( "--device", default=None, help="Device to run inference on. If not specified, will automatically detect and use CUDA or MPS if available, else CPU.", ) parser.add_argument( "--precision", choices=["bfloat16", "mixed_precision"], default="bfloat16", help="Sets the precision for the transformer and tokenizer. Default is bfloat16. If 'mixed_precision' is enabled, it moves to mixed-precision.", ) # VAE noise augmentation parser.add_argument( "--decode_timestep", type=float, default=0.025, help="Timestep for decoding noise", ) parser.add_argument( "--decode_noise_scale", type=float, default=0.0125, help="Noise level for decoding noise", ) # Prompts parser.add_argument( "--prompt", type=str, help="Text prompt to guide generation", ) parser.add_argument( "--negative_prompt", type=str, default="worst quality, inconsistent motion, blurry, jittery, distorted", help="Negative prompt for undesired features", ) parser.add_argument( "--low_vram", action="store_true", ) parser.add_argument( "--offload_to_cpu", action="store_true", help="Offloading unnecessary computations to CPU.", ) parser.add_argument( "--text_encoder_model_name_or_path", type=str, default="PixArt-alpha/PixArt-XL-2-1024-MS", help="Local path or model identifier for both the tokenizer and text encoder. Defaults to pretrained model on Hugging Face.", ) # Conditioning arguments parser.add_argument( "--conditioning_media_paths", type=str, nargs="*", help="List of paths to conditioning media (images or videos). Each path will be used as a conditioning item.", ) parser.add_argument( "--conditioning_strengths", type=float, nargs="*", help="List of conditioning strengths (between 0 and 1) for each conditioning item. Must match the number of conditioning items.", ) parser.add_argument( "--conditioning_start_frames", type=int, nargs="*", help="List of frame indices where each conditioning item should be applied. Must match the number of conditioning items.", ) parser.add_argument( "--sampler", type=str, choices=["uniform", "linear-quadratic"], default=None, help="Sampler to use for noise scheduling. Can be either 'uniform' or 'linear-quadratic'. If not specified, uses the sampler from the checkpoint.", ) # Prompt enhancement parser.add_argument( "--prompt_enhancement_words_threshold", type=int, default=50, help="Enable prompt enhancement only if input prompt has fewer words than this threshold. Set to 0 to disable enhancement completely.", ) parser.add_argument( "--prompt_enhancer_image_caption_model_name_or_path", type=str, default="MiaoshouAI/Florence-2-large-PromptGen-v2.0", help="Path to the image caption model", ) parser.add_argument( "--prompt_enhancer_llm_model_name_or_path", type=str, default="unsloth/Llama-3.2-3B-Instruct", help="Path to the LLM model, default is Llama-3.2-3B-Instruct, but you can use other models like Llama-3.1-8B-Instruct, or other models supported by Hugging Face", ) args = parser.parse_args() logger.warning(f"Running generation with arguments: {args}") infer(**vars(args)) def create_ltx_video_pipeline( ckpt_path: str, precision: str, text_encoder_model_name_or_path: str, sampler: Optional[str] = None, device: Optional[str] = None, lowVram: bool = False, enhance_prompt: bool = False, prompt_enhancer_image_caption_model_name_or_path: Optional[str] = None, prompt_enhancer_llm_model_name_or_path: Optional[str] = None, ) -> LTXVideoPipeline: ckpt_path = Path(ckpt_path) assert os.path.exists( ckpt_path ), f"Ckpt path provided (--ckpt_path) {ckpt_path} does not exist" vae = CausalVideoAutoencoder.from_pretrained(ckpt_path) transformer = Transformer3DModel.from_pretrained(ckpt_path) # Use constructor if sampler is specified, otherwise use from_pretrained if sampler: scheduler = RectifiedFlowScheduler( sampler=("Uniform" if sampler.lower() == "uniform" else "LinearQuadratic") ) else: scheduler = RectifiedFlowScheduler.from_pretrained(ckpt_path) text_encoder = T5EncoderModel.from_pretrained(text_encoder_model_name_or_path, subfolder="text_encoder") patchifier = SymmetricPatchifier(patch_size=1) tokenizer = T5Tokenizer.from_pretrained( text_encoder_model_name_or_path, subfolder="tokenizer" ) if torch.cuda.is_available() and not lowVram: text_encoder = text_encoder.to(device) else: text_encoder = text_encoder.to("cpu") text_encoder = text_encoder.to(dtype=torch.bfloat16, device="cpu") transformer = transformer.to(device) vae = vae.to(device) # text_encoder = text_encoder.to(device) if enhance_prompt: prompt_enhancer_image_caption_model = AutoModelForCausalLM.from_pretrained( prompt_enhancer_image_caption_model_name_or_path, trust_remote_code=True ) prompt_enhancer_image_caption_processor = AutoProcessor.from_pretrained( prompt_enhancer_image_caption_model_name_or_path, trust_remote_code=True ) prompt_enhancer_llm_model = AutoModelForCausalLM.from_pretrained( prompt_enhancer_llm_model_name_or_path, torch_dtype="bfloat16", ) prompt_enhancer_llm_tokenizer = AutoTokenizer.from_pretrained( prompt_enhancer_llm_model_name_or_path, ) else: prompt_enhancer_image_caption_model = None prompt_enhancer_image_caption_processor = None prompt_enhancer_llm_model = None prompt_enhancer_llm_tokenizer = None vae = vae.to(torch.bfloat16) if precision == "bfloat16" and transformer.dtype != torch.bfloat16: transformer = transformer.to(torch.bfloat16) # text_encoder = text_encoder.to(torch.bfloat16) # Use submodels for the pipeline submodel_dict = { "transformer": transformer, "patchifier": patchifier, "text_encoder": text_encoder, "tokenizer": tokenizer, "scheduler": scheduler, "vae": vae, "prompt_enhancer_image_caption_model": prompt_enhancer_image_caption_model, "prompt_enhancer_image_caption_processor": prompt_enhancer_image_caption_processor, "prompt_enhancer_llm_model": prompt_enhancer_llm_model, "prompt_enhancer_llm_tokenizer": prompt_enhancer_llm_tokenizer, } pipeline = LTXVideoPipeline(**submodel_dict) if torch.cuda.is_available() and not lowVram: pipeline = pipeline.to("cuda") return pipeline def infer( ckpt_path: str, output_path: Optional[str], seed: int, num_inference_steps: int, num_images_per_prompt: int, guidance_scale: float, stg_scale: float, stg_rescale: float, stg_mode: str, stg_skip_layers: str, image_cond_noise_scale: float, height: Optional[int], width: Optional[int], num_frames: int, frame_rate: int, precision: str, decode_timestep: float, decode_noise_scale: float, prompt: str, negative_prompt: str, low_vram: bool, offload_to_cpu: bool, text_encoder_model_name_or_path: str, conditioning_media_paths: Optional[List[str]] = None, conditioning_strengths: Optional[List[float]] = None, conditioning_start_frames: Optional[List[int]] = None, sampler: Optional[str] = None, device: Optional[str] = None, prompt_enhancement_words_threshold: int = 50, prompt_enhancer_image_caption_model_name_or_path: str = "MiaoshouAI/Florence-2-large-PromptGen-v2.0", prompt_enhancer_llm_model_name_or_path: str = "unsloth/Llama-3.2-3B-Instruct", **kwargs, ): if kwargs.get("input_image_path", None): logger.warning( "Please use conditioning_media_paths instead of input_image_path." ) assert not conditioning_media_paths and not conditioning_start_frames conditioning_media_paths = [kwargs["input_image_path"]] conditioning_start_frames = [0] # Validate conditioning arguments if conditioning_media_paths: # Use default strengths of 1.0 if not conditioning_strengths: conditioning_strengths = [1.0] * len(conditioning_media_paths) if not conditioning_start_frames: raise ValueError( "If `conditioning_media_paths` is provided, " "`conditioning_start_frames` must also be provided" ) if len(conditioning_media_paths) != len(conditioning_strengths) or len( conditioning_media_paths ) != len(conditioning_start_frames): raise ValueError( "`conditioning_media_paths`, `conditioning_strengths`, " "and `conditioning_start_frames` must have the same length" ) if any(s < 0 or s > 1 for s in conditioning_strengths): raise ValueError("All conditioning strengths must be between 0 and 1") if any(f < 0 or f >= num_frames for f in conditioning_start_frames): raise ValueError( f"All conditioning start frames must be between 0 and {num_frames-1}" ) seed_everething(seed) if offload_to_cpu and not torch.cuda.is_available(): logger.warning( "offload_to_cpu is set to True, but offloading will not occur since the model is already running on CPU." ) offload_to_cpu = False else: offload_to_cpu = offload_to_cpu and get_total_gpu_memory() < 30 output_dir = ( Path(output_path) if output_path else Path(f"outputs/{datetime.today().strftime('%Y-%m-%d')}") ) output_dir.mkdir(parents=True, exist_ok=True) # Adjust dimensions to be divisible by 32 and num_frames to be (N * 8 + 1) height_padded = ((height - 1) // 32 + 1) * 32 width_padded = ((width - 1) // 32 + 1) * 32 num_frames_padded = ((num_frames - 2) // 8 + 1) * 8 + 1 padding = calculate_padding(height, width, height_padded, width_padded) logger.warning( f"Padded dimensions: {height_padded}x{width_padded}x{num_frames_padded}" ) prompt_word_count = len(prompt.split()) enhance_prompt = ( prompt_enhancement_words_threshold > 0 and prompt_word_count < prompt_enhancement_words_threshold ) if prompt_enhancement_words_threshold > 0 and not enhance_prompt: logger.info( f"Prompt has {prompt_word_count} words, which exceeds the threshold of {prompt_enhancement_words_threshold}. Prompt enhancement disabled." ) pipeline = create_ltx_video_pipeline( ckpt_path=ckpt_path, precision=precision, text_encoder_model_name_or_path=text_encoder_model_name_or_path, sampler=sampler, device=kwargs.get("device", get_device()), lowVram=low_vram, enhance_prompt=enhance_prompt, prompt_enhancer_image_caption_model_name_or_path=prompt_enhancer_image_caption_model_name_or_path, prompt_enhancer_llm_model_name_or_path=prompt_enhancer_llm_model_name_or_path, ) conditioning_items = ( prepare_conditioning( conditioning_media_paths=conditioning_media_paths, conditioning_strengths=conditioning_strengths, conditioning_start_frames=conditioning_start_frames, height=height, width=width, num_frames=num_frames, padding=padding, pipeline=pipeline, ) if conditioning_media_paths else None ) # Set spatiotemporal guidance skip_block_list = [int(x.strip()) for x in stg_skip_layers.split(",")] if stg_mode.lower() == "stg_av" or stg_mode.lower() == "attention_values": skip_layer_strategy = SkipLayerStrategy.AttentionValues elif stg_mode.lower() == "stg_as" or stg_mode.lower() == "attention_skip": skip_layer_strategy = SkipLayerStrategy.AttentionSkip elif stg_mode.lower() == "stg_r" or stg_mode.lower() == "residual": skip_layer_strategy = SkipLayerStrategy.Residual elif stg_mode.lower() == "stg_t" or stg_mode.lower() == "transformer_block": skip_layer_strategy = SkipLayerStrategy.TransformerBlock else: raise ValueError(f"Invalid spatiotemporal guidance mode: {stg_mode}") # Prepare input for the pipeline sample = { "prompt": prompt, "prompt_attention_mask": None, "negative_prompt": negative_prompt, "negative_prompt_attention_mask": None, } device = device or get_device() generator = torch.Generator(device=device).manual_seed(seed) images = pipeline( num_inference_steps=num_inference_steps, num_images_per_prompt=num_images_per_prompt, guidance_scale=guidance_scale, skip_layer_strategy=skip_layer_strategy, skip_block_list=skip_block_list, stg_scale=stg_scale, do_rescaling=stg_rescale != 1, rescaling_scale=stg_rescale, generator=generator, output_type="pt", callback_on_step_end=None, height=height_padded, width=width_padded, num_frames=num_frames_padded, frame_rate=frame_rate, **sample, conditioning_items=conditioning_items, is_video=True, vae_per_channel_normalize=True, image_cond_noise_scale=image_cond_noise_scale, decode_timestep=decode_timestep, decode_noise_scale=decode_noise_scale, mixed_precision=(precision == "mixed_precision"), offload_to_cpu=offload_to_cpu, device=device, enhance_prompt=enhance_prompt, ).images # Crop the padded images to the desired resolution and number of frames (pad_left, pad_right, pad_top, pad_bottom) = padding pad_bottom = -pad_bottom pad_right = -pad_right if pad_bottom == 0: pad_bottom = images.shape[3] if pad_right == 0: pad_right = images.shape[4] images = images[:, :, :num_frames, pad_top:pad_bottom, pad_left:pad_right] for i in range(images.shape[0]): # Gathering from B, C, F, H, W to C, F, H, W and then permuting to F, H, W, C video_np = images[i].permute(1, 2, 3, 0).cpu().float().numpy() # Unnormalizing images to [0, 255] range video_np = (video_np * 255).astype(np.uint8) fps = frame_rate height, width = video_np.shape[1:3] # In case a single image is generated if video_np.shape[0] == 1: output_filename = get_unique_filename( f"image_output_{i}", ".png", prompt=prompt, seed=seed, resolution=(height, width, num_frames), dir=output_dir, ) imageio.imwrite(output_filename, video_np[0]) else: output_filename = get_unique_filename( f"video_output_{i}", ".mp4", prompt=prompt, seed=seed, resolution=(height, width, num_frames), dir=output_dir, ) # Write video with imageio.get_writer(output_filename, fps=fps) as video: for frame in video_np: video.append_data(frame) logger.warning(f"Output saved to {output_dir}") def prepare_conditioning( conditioning_media_paths: List[str], conditioning_strengths: List[float], conditioning_start_frames: List[int], height: int, width: int, num_frames: int, padding: tuple[int, int, int, int], pipeline: LTXVideoPipeline, ) -> Optional[List[ConditioningItem]]: """Prepare conditioning items based on input media paths and their parameters. Args: conditioning_media_paths: List of paths to conditioning media (images or videos) conditioning_strengths: List of conditioning strengths for each media item conditioning_start_frames: List of frame indices where each item should be applied height: Height of the output frames width: Width of the output frames num_frames: Number of frames in the output video padding: Padding to apply to the frames pipeline: LTXVideoPipeline object used for condition video trimming Returns: A list of ConditioningItem objects. """ conditioning_items = [] for path, strength, start_frame in zip( conditioning_media_paths, conditioning_strengths, conditioning_start_frames ): # Check if the path points to an image or video is_video = any( path.lower().endswith(ext) for ext in [".mp4", ".avi", ".mov", ".mkv"] ) if is_video: reader = imageio.get_reader(path) orig_num_input_frames = reader.count_frames() num_input_frames = pipeline.trim_conditioning_sequence( start_frame, orig_num_input_frames, num_frames ) if num_input_frames < orig_num_input_frames: logger.warning( f"Trimming conditioning video {path} from {orig_num_input_frames} to {num_input_frames} frames." ) # Read and preprocess the relevant frames from the video file. frames = [] for i in range(num_input_frames): frame = Image.fromarray(reader.get_data(i)) frame_tensor = load_image_to_tensor_with_resize_and_crop( frame, height, width ) frame_tensor = torch.nn.functional.pad(frame_tensor, padding) frames.append(frame_tensor) reader.close() # Stack frames along the temporal dimension video_tensor = torch.cat(frames, dim=2) conditioning_items.append( ConditioningItem(video_tensor, start_frame, strength) ) else: # Input image frame_tensor = load_image_to_tensor_with_resize_and_crop( path, height, width ) frame_tensor = torch.nn.functional.pad(frame_tensor, padding) conditioning_items.append( ConditioningItem(frame_tensor, start_frame, strength) ) return conditioning_items if __name__ == "__main__": main()