from typing import List, Optional import torch from utils.wan_wrapper import WanDiffusionWrapper, WanTextEncoder, WanVAEWrapper class CausalInferencePipeline(torch.nn.Module): def __init__( self, args, device, generator=None, text_encoder=None, vae=None ): super().__init__() # Step 1: Initialize all models self.generator = WanDiffusionWrapper( **getattr(args, "model_kwargs", {}), is_causal=True) if generator is None else generator self.text_encoder = WanTextEncoder() if text_encoder is None else text_encoder self.vae = WanVAEWrapper() if vae is None else vae # Step 2: Initialize all causal hyperparmeters self.scheduler = self.generator.get_scheduler() self.denoising_step_list = torch.tensor( args.denoising_step_list, dtype=torch.long) if args.warp_denoising_step: timesteps = torch.cat((self.scheduler.timesteps.cpu(), torch.tensor([0], dtype=torch.float32))) self.denoising_step_list = timesteps[1000 - self.denoising_step_list] self.num_transformer_blocks = 30 self.frame_seq_length = 1560 self.kv_cache1 = None self.args = args self.num_frame_per_block = getattr(args, "num_frame_per_block", 1) self.independent_first_frame = args.independent_first_frame self.local_attn_size = self.generator.model.local_attn_size print(f"KV inference with {self.num_frame_per_block} frames per block") if self.num_frame_per_block > 1: self.generator.model.num_frame_per_block = self.num_frame_per_block def inference( self, noise: torch.Tensor, text_prompts: List[str], initial_latent: Optional[torch.Tensor] = None, return_latents: bool = False, profile: bool = False ) -> torch.Tensor: """ Perform inference on the given noise and text prompts. Inputs: noise (torch.Tensor): The input noise tensor of shape (batch_size, num_output_frames, num_channels, height, width). text_prompts (List[str]): The list of text prompts. initial_latent (torch.Tensor): The initial latent tensor of shape (batch_size, num_input_frames, num_channels, height, width). If num_input_frames is 1, perform image to video. If num_input_frames is greater than 1, perform video extension. return_latents (bool): Whether to return the latents. Outputs: video (torch.Tensor): The generated video tensor of shape (batch_size, num_output_frames, num_channels, height, width). It is normalized to be in the range [0, 1]. """ batch_size, num_frames, num_channels, height, width = noise.shape if not self.independent_first_frame or (self.independent_first_frame and initial_latent is not None): # If the first frame is independent and the first frame is provided, then the number of frames in the # noise should still be a multiple of num_frame_per_block assert num_frames % self.num_frame_per_block == 0 num_blocks = num_frames // self.num_frame_per_block else: # Using a [1, 4, 4, 4, 4, 4, ...] model to generate a video without image conditioning assert (num_frames - 1) % self.num_frame_per_block == 0 num_blocks = (num_frames - 1) // self.num_frame_per_block num_input_frames = initial_latent.shape[1] if initial_latent is not None else 0 num_output_frames = num_frames + num_input_frames # add the initial latent frames conditional_dict = self.text_encoder( text_prompts=text_prompts ) output = torch.zeros( [batch_size, num_output_frames, num_channels, height, width], device=noise.device, dtype=noise.dtype ) # Set up profiling if requested if profile: init_start = torch.cuda.Event(enable_timing=True) init_end = torch.cuda.Event(enable_timing=True) diffusion_start = torch.cuda.Event(enable_timing=True) diffusion_end = torch.cuda.Event(enable_timing=True) vae_start = torch.cuda.Event(enable_timing=True) vae_end = torch.cuda.Event(enable_timing=True) block_times = [] block_start = torch.cuda.Event(enable_timing=True) block_end = torch.cuda.Event(enable_timing=True) init_start.record() # Step 1: Initialize KV cache to all zeros if self.kv_cache1 is None: self._initialize_kv_cache( batch_size=batch_size, dtype=noise.dtype, device=noise.device ) self._initialize_crossattn_cache( batch_size=batch_size, dtype=noise.dtype, device=noise.device ) else: # reset cross attn cache for block_index in range(self.num_transformer_blocks): self.crossattn_cache[block_index]["is_init"] = False # reset kv cache for block_index in range(len(self.kv_cache1)): self.kv_cache1[block_index]["global_end_index"] = torch.tensor( [0], dtype=torch.long, device=noise.device) self.kv_cache1[block_index]["local_end_index"] = torch.tensor( [0], dtype=torch.long, device=noise.device) # Step 2: Cache context feature current_start_frame = 0 if initial_latent is not None: timestep = torch.ones([batch_size, 1], device=noise.device, dtype=torch.int64) * 0 if self.independent_first_frame: # Assume num_input_frames is 1 + self.num_frame_per_block * num_input_blocks assert (num_input_frames - 1) % self.num_frame_per_block == 0 num_input_blocks = (num_input_frames - 1) // self.num_frame_per_block output[:, :1] = initial_latent[:, :1] self.generator( noisy_image_or_video=initial_latent[:, :1], conditional_dict=conditional_dict, timestep=timestep * 0, kv_cache=self.kv_cache1, crossattn_cache=self.crossattn_cache, current_start=current_start_frame * self.frame_seq_length, ) current_start_frame += 1 else: # Assume num_input_frames is self.num_frame_per_block * num_input_blocks assert num_input_frames % self.num_frame_per_block == 0 num_input_blocks = num_input_frames // self.num_frame_per_block for _ in range(num_input_blocks): current_ref_latents = \ initial_latent[:, current_start_frame:current_start_frame + self.num_frame_per_block] output[:, current_start_frame:current_start_frame + self.num_frame_per_block] = current_ref_latents self.generator( noisy_image_or_video=current_ref_latents, conditional_dict=conditional_dict, timestep=timestep * 0, kv_cache=self.kv_cache1, crossattn_cache=self.crossattn_cache, current_start=current_start_frame * self.frame_seq_length, ) current_start_frame += self.num_frame_per_block if profile: init_end.record() torch.cuda.synchronize() diffusion_start.record() # Step 3: Temporal denoising loop all_num_frames = [self.num_frame_per_block] * num_blocks if self.independent_first_frame and initial_latent is None: all_num_frames = [1] + all_num_frames for current_num_frames in all_num_frames: if profile: block_start.record() noisy_input = noise[ :, current_start_frame - num_input_frames:current_start_frame + current_num_frames - num_input_frames] # Step 3.1: Spatial denoising loop for index, current_timestep in enumerate(self.denoising_step_list): print(f"current_timestep: {current_timestep}") # set current timestep timestep = torch.ones( [batch_size, current_num_frames], device=noise.device, dtype=torch.int64) * current_timestep if index < len(self.denoising_step_list) - 1: _, denoised_pred = self.generator( noisy_image_or_video=noisy_input, conditional_dict=conditional_dict, timestep=timestep, kv_cache=self.kv_cache1, crossattn_cache=self.crossattn_cache, current_start=current_start_frame * self.frame_seq_length ) next_timestep = self.denoising_step_list[index + 1] noisy_input = self.scheduler.add_noise( denoised_pred.flatten(0, 1), torch.randn_like(denoised_pred.flatten(0, 1)), next_timestep * torch.ones( [batch_size * current_num_frames], device=noise.device, dtype=torch.long) ).unflatten(0, denoised_pred.shape[:2]) else: # for getting real output _, denoised_pred = self.generator( noisy_image_or_video=noisy_input, conditional_dict=conditional_dict, timestep=timestep, kv_cache=self.kv_cache1, crossattn_cache=self.crossattn_cache, current_start=current_start_frame * self.frame_seq_length ) # Step 3.2: record the model's output output[:, current_start_frame:current_start_frame + current_num_frames] = denoised_pred # Step 3.3: rerun with timestep zero to update KV cache using clean context context_timestep = torch.ones_like(timestep) * self.args.context_noise self.generator( noisy_image_or_video=denoised_pred, conditional_dict=conditional_dict, timestep=context_timestep, kv_cache=self.kv_cache1, crossattn_cache=self.crossattn_cache, current_start=current_start_frame * self.frame_seq_length, ) if profile: block_end.record() torch.cuda.synchronize() block_time = block_start.elapsed_time(block_end) block_times.append(block_time) # Step 3.4: update the start and end frame indices current_start_frame += current_num_frames if profile: # End diffusion timing and synchronize CUDA diffusion_end.record() torch.cuda.synchronize() diffusion_time = diffusion_start.elapsed_time(diffusion_end) init_time = init_start.elapsed_time(init_end) vae_start.record() # Step 4: Decode the output video = self.vae.decode_to_pixel(output, use_cache=False) video = (video * 0.5 + 0.5).clamp(0, 1) if profile: # End VAE timing and synchronize CUDA vae_end.record() torch.cuda.synchronize() vae_time = vae_start.elapsed_time(vae_end) total_time = init_time + diffusion_time + vae_time print("Profiling results:") print(f" - Initialization/caching time: {init_time:.2f} ms ({100 * init_time / total_time:.2f}%)") print(f" - Diffusion generation time: {diffusion_time:.2f} ms ({100 * diffusion_time / total_time:.2f}%)") for i, block_time in enumerate(block_times): print(f" - Block {i} generation time: {block_time:.2f} ms ({100 * block_time / diffusion_time:.2f}% of diffusion)") print(f" - VAE decoding time: {vae_time:.2f} ms ({100 * vae_time / total_time:.2f}%)") print(f" - Total time: {total_time:.2f} ms") if return_latents: return video, output else: return video def _initialize_kv_cache(self, batch_size, dtype, device): """ Initialize a Per-GPU KV cache for the Wan model. """ kv_cache1 = [] if self.local_attn_size != -1: # Use the local attention size to compute the KV cache size kv_cache_size = self.local_attn_size * self.frame_seq_length else: # Use the default KV cache size kv_cache_size = 32760 for _ in range(self.num_transformer_blocks): kv_cache1.append({ "k": torch.zeros([batch_size, kv_cache_size, 12, 128], dtype=dtype, device=device), "v": torch.zeros([batch_size, kv_cache_size, 12, 128], dtype=dtype, device=device), "global_end_index": torch.tensor([0], dtype=torch.long, device=device), "local_end_index": torch.tensor([0], dtype=torch.long, device=device) }) self.kv_cache1 = kv_cache1 # always store the clean cache def _initialize_crossattn_cache(self, batch_size, dtype, device): """ Initialize a Per-GPU cross-attention cache for the Wan model. """ crossattn_cache = [] for _ in range(self.num_transformer_blocks): crossattn_cache.append({ "k": torch.zeros([batch_size, 512, 12, 128], dtype=dtype, device=device), "v": torch.zeros([batch_size, 512, 12, 128], dtype=dtype, device=device), "is_init": False }) self.crossattn_cache = crossattn_cache