# SPDX-FileCopyrightText: Copyright (c) 2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved. # SPDX-License-Identifier: Apache-2.0 # # Licensed under the Apache License, Version 2.0 (the "License"); # you may not use this file except in compliance with the License. # You may obtain a copy of the License at # # http://www.apache.org/licenses/LICENSE-2.0 # # Unless required by applicable law or agreed to in writing, software # distributed under the License is distributed on an "AS IS" BASIS, # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. # See the License for the specific language governing permissions and # limitations under the License. import math from abc import ABC, abstractmethod import torch import torch.nn.functional as F from einops import rearrange from torch.nn.modules import Module from cosmos_predict1.diffusion.training.module.pretrained_vae_base import JITVAE, BaseVAE, StateDictVAE from cosmos_predict1.utils import log class VideoTokenizerInterface(ABC): @abstractmethod def encode(self, state: torch.Tensor) -> torch.Tensor: pass @abstractmethod def decode(self, latent: torch.Tensor) -> torch.Tensor: pass @abstractmethod def get_latent_num_frames(self, num_pixel_frames: int) -> int: pass @abstractmethod def get_pixel_num_frames(self, num_latent_frames: int) -> int: pass @property @abstractmethod def spatial_compression_factor(self): pass @property @abstractmethod def temporal_compression_factor(self): pass @property @abstractmethod def spatial_resolution(self): pass @property @abstractmethod def pixel_chunk_duration(self): pass @property @abstractmethod def latent_chunk_duration(self): pass @property def is_chunk_overlap(self): return False class BasePretrainedVideoTokenizer(ABC): """ Base class for a pretrained video tokenizer that handles chunking of video data for efficient processing. Args: pixel_chunk_duration (int): The duration (in number of frames) of each chunk of video data at the pixel level. temporal_compress_factor (int): The factor by which the video data is temporally compressed during processing. max_enc_batch_size (int): The maximum batch size to process in one go during encoding to avoid memory overflow. max_dec_batch_size (int): The maximum batch size to process in one go during decoding to avoid memory overflow. The class introduces parameters for managing temporal chunks (`pixel_chunk_duration` and `temporal_compress_factor`) which define how video data is subdivided and compressed during the encoding and decoding processes. The `max_enc_batch_size` and `max_dec_batch_size` parameters allow processing in smaller batches to handle memory constraints. """ def __init__( self, pixel_chunk_duration: int = 17, temporal_compress_factor: int = 8, max_enc_batch_size: int = 8, max_dec_batch_size: int = 4, ): self._pixel_chunk_duration = pixel_chunk_duration self._temporal_compress_factor = temporal_compress_factor self.max_enc_batch_size = max_enc_batch_size self.max_dec_batch_size = max_dec_batch_size def register_mean_std(self, mean_std_fp: str) -> None: latent_mean, latent_std = torch.load(mean_std_fp, map_location="cuda", weights_only=True) latent_mean = latent_mean.view(self.latent_ch, -1)[:, : self.latent_chunk_duration] latent_std = latent_std.view(self.latent_ch, -1)[:, : self.latent_chunk_duration] target_shape = [1, self.latent_ch, self.latent_chunk_duration, 1, 1] self.register_buffer( "latent_mean", latent_mean.to(self.dtype).reshape(*target_shape), persistent=False, ) self.register_buffer( "latent_std", latent_std.to(self.dtype).reshape(*target_shape), persistent=False, ) def transform_encode_state_shape(self, state: torch.Tensor) -> torch.Tensor: """ Rearranges the input state tensor to the required shape for encoding video data. Mainly for chunk based encoding """ B, C, T, H, W = state.shape assert ( T % self.pixel_chunk_duration == 0 ), f"Temporal dimension {T} is not divisible by chunk_length {self.pixel_chunk_duration}" return rearrange(state, "b c (n t) h w -> (b n) c t h w", t=self.pixel_chunk_duration) def transform_decode_state_shape(self, latent: torch.Tensor) -> None: B, _, T, _, _ = latent.shape assert ( T % self.latent_chunk_duration == 0 ), f"Temporal dimension {T} is not divisible by chunk_length {self.latent_chunk_duration}" return rearrange(latent, "b c (n t) h w -> (b n) c t h w", t=self.latent_chunk_duration) @torch.no_grad() def encode(self, state: torch.Tensor) -> torch.Tensor: if self._temporal_compress_factor == 1: _, _, origin_T, _, _ = state.shape state = rearrange(state, "b c t h w -> (b t) c 1 h w") B, C, T, H, W = state.shape state = self.transform_encode_state_shape(state) # use max_enc_batch_size to avoid OOM if state.shape[0] > self.max_enc_batch_size: latent = [] for i in range(0, state.shape[0], self.max_enc_batch_size): latent.append(super().encode(state[i : i + self.max_enc_batch_size])) latent = torch.cat(latent, dim=0) else: latent = super().encode(state) latent = rearrange(latent, "(b n) c t h w -> b c (n t) h w", b=B) if self._temporal_compress_factor == 1: latent = rearrange(latent, "(b t) c 1 h w -> b c t h w", t=origin_T) return latent @torch.no_grad() def decode(self, latent: torch.Tensor) -> torch.Tensor: """ Decodes a batch of latent representations into video frames by applying temporal chunking. Similar to encode, it handles video data by processing smaller temporal chunks to reconstruct the original video dimensions. It can also decode single frame image data. Args: latent (torch.Tensor): The latent space tensor containing encoded video data. Returns: torch.Tensor: The decoded video tensor reconstructed from latent space. """ if self._temporal_compress_factor == 1: _, _, origin_T, _, _ = latent.shape latent = rearrange(latent, "b c t h w -> (b t) c 1 h w") B, _, T, _, _ = latent.shape latent = self.transform_decode_state_shape(latent) # use max_enc_batch_size to avoid OOM if latent.shape[0] > self.max_dec_batch_size: state = [] for i in range(0, latent.shape[0], self.max_dec_batch_size): state.append(super().decode(latent[i : i + self.max_dec_batch_size])) state = torch.cat(state, dim=0) else: state = super().decode(latent) assert state.shape[2] == self.pixel_chunk_duration state = rearrange(state, "(b n) c t h w -> b c (n t) h w", b=B) if self._temporal_compress_factor == 1: return rearrange(state, "(b t) c 1 h w -> b c t h w", t=origin_T) return state @property def pixel_chunk_duration(self) -> int: return self._pixel_chunk_duration @property def latent_chunk_duration(self) -> int: # return self._latent_chunk_duration assert (self.pixel_chunk_duration - 1) % self.temporal_compression_factor == 0, ( f"Pixel chunk duration {self.pixel_chunk_duration} is not divisible by latent chunk duration " f"{self.latent_chunk_duration}" ) return (self.pixel_chunk_duration - 1) // self.temporal_compression_factor + 1 @property def temporal_compression_factor(self): return self._temporal_compress_factor def get_latent_num_frames(self, num_pixel_frames: int) -> int: if num_pixel_frames == 1: return 1 assert ( num_pixel_frames % self.pixel_chunk_duration == 0 ), f"Temporal dimension {num_pixel_frames} is not divisible by chunk_length {self.pixel_chunk_duration}" return num_pixel_frames // self.pixel_chunk_duration * self.latent_chunk_duration def get_pixel_num_frames(self, num_latent_frames: int) -> int: if num_latent_frames == 1: return 1 assert ( num_latent_frames % self.latent_chunk_duration == 0 ), f"Temporal dimension {num_latent_frames} is not divisible by chunk_length {self.latent_chunk_duration}" return num_latent_frames // self.latent_chunk_duration * self.pixel_chunk_duration class VideoJITTokenizer(BasePretrainedVideoTokenizer, JITVAE, VideoTokenizerInterface): """ Instance of BasePretrainedVideoVAE that loads encoder and decoder from JIT scripted module file """ def __init__( self, enc_fp: str, dec_fp: str, name: str, mean_std_fp: str, latent_ch: int = 16, is_bf16: bool = True, spatial_compression_factor: int = 16, temporal_compression_factor: int = 8, pixel_chunk_duration: int = 17, max_enc_batch_size: int = 8, max_dec_batch_size: int = 4, spatial_resolution: str = "720", ): super().__init__(pixel_chunk_duration, temporal_compression_factor, max_enc_batch_size, max_dec_batch_size) super(BasePretrainedVideoTokenizer, self).__init__(enc_fp, dec_fp, name, mean_std_fp, latent_ch, False, is_bf16) self._spatial_compression_factor = spatial_compression_factor self._spatial_resolution = spatial_resolution @property def spatial_compression_factor(self): return self._spatial_compression_factor @property def spatial_resolution(self) -> str: return self._spatial_resolution class VideoStateDictTokenizer(BasePretrainedVideoTokenizer, StateDictVAE, VideoTokenizerInterface): """ Instance of BasePretrainedVideoVAE that loads encoder and decoder from state_dict checkpoint """ def __init__( self, enc_fp: str, dec_fp: str, vae: torch.nn.Module, name: str, mean_std_fp: str, latent_ch: int = 16, is_bf16: bool = True, spatial_compression_factor: int = 16, temporal_compression_factor: int = 8, pixel_chunk_duration: int = 17, max_enc_batch_size: int = 8, max_dec_batch_size: int = 4, spatial_resolution: str = "720", ): super().__init__(pixel_chunk_duration, temporal_compression_factor, max_enc_batch_size, max_dec_batch_size) super(BasePretrainedVideoTokenizer, self).__init__( enc_fp, dec_fp, vae, name, mean_std_fp, latent_ch, is_image=False, is_bf16=is_bf16 ) self._spatial_compression_factor = spatial_compression_factor self._spatial_resolution = spatial_resolution @property def spatial_compression_factor(self): return self._spatial_compression_factor @property def spatial_resolution(self) -> str: return self._spatial_resolution class VideoJITVAEChunkWiseTokenizer(VideoJITTokenizer): """ Do temporal chunk wise encoding and decoding. """ def __init__( self, enc_fp: str, dec_fp: str, name: str, mean_std_fp: str, spatial_compression_factor: int, latent_ch: int = 16, is_bf16: bool = True, full_duration: int = 121, chunk_duration: int = 49, temporal_compression_factor: int = 8, max_enc_batch_size: int = 8, max_dec_batch_size: int = 4, spatial_resolution="720", overlap_size: int = 9, ): self._latent_chunk_duration = ( chunk_duration - 1 ) // temporal_compression_factor + 1 # need to set before super init self._latent_full_duration = (full_duration - 1) // temporal_compression_factor + 1 super().__init__( enc_fp=enc_fp, dec_fp=dec_fp, name=name, mean_std_fp=mean_std_fp, latent_ch=latent_ch, is_bf16=is_bf16, pixel_chunk_duration=chunk_duration, temporal_compression_factor=temporal_compression_factor, max_enc_batch_size=max_enc_batch_size, max_dec_batch_size=max_dec_batch_size, spatial_resolution=spatial_resolution, spatial_compression_factor=spatial_compression_factor, ) self.overlap_size = overlap_size self.full_duration = full_duration # make sure full_duration is divisible by chunk_duration with pre-set overlap size assert (full_duration - overlap_size) % (chunk_duration - overlap_size) == 0 @property def latent_chunk_duration(self) -> int: return self._latent_chunk_duration @property def latent_full_duration(self) -> int: return self._latent_full_duration def get_latent_num_frames(self, num_pixel_frames: int) -> int: if num_pixel_frames == 1: return 1 assert ( num_pixel_frames % self.full_duration == 0 ), f"Temporal dimension {num_pixel_frames} is not divisible by chunk_length {self.full_duration}" return num_pixel_frames // self.full_duration * self.latent_full_duration def get_pixel_num_frames(self, num_latent_frames: int) -> int: if num_latent_frames == 1: return 1 assert ( num_latent_frames % self.latent_full_duration == 0 ), f"Temporal dimension {num_latent_frames} is not divisible by chunk_length {self.latent_full_duration}" return num_latent_frames // self.latent_full_duration * self.full_duration def transform_encode_state_shape(self, state: torch.Tensor) -> torch.Tensor: # This is a hack impl, should be improved later return state def transform_decode_state_shape(self, latent: torch.Tensor) -> torch.Tensor: # This is a hack impl, should be improved later return latent def _impl_encode(self, state: torch.Tensor) -> torch.Tensor: in_dtype = state.dtype latent_mean = self.latent_mean.to(in_dtype) latent_std = self.latent_std.to(in_dtype) encoded_state = self.encoder(state.to(self.dtype)) if isinstance(encoded_state, torch.Tensor): pass elif isinstance(encoded_state, tuple): assert isinstance(encoded_state[0], torch.Tensor) encoded_state = encoded_state[0] else: raise ValueError("Invalid type of encoded state") return (encoded_state.to(in_dtype) - latent_mean) / latent_std @torch.no_grad() def encode(self, state: torch.Tensor) -> torch.Tensor: B, C, T, H, W = state.shape assert state.shape[2] == self.full_duration # Calculate the number of overlapping windows/chunks # Each window has a duration of self.pixel_chunk_duration frames # The overlap between consecutive windows is self.overlap_size frames num_windows = (T - self.pixel_chunk_duration) // (self.pixel_chunk_duration - self.overlap_size) # Calculate the total number of frames covered by the windows num_windowed_frames = self.pixel_chunk_duration + num_windows * (self.pixel_chunk_duration - self.overlap_size) assert num_windowed_frames == T # only handle case where number frames can be separated equally # Prepare a list to hold overlapping chunks of the input state pack_list = [state[:, :, : self.pixel_chunk_duration]] + [ state[ :, :, (ii + 1) * (self.pixel_chunk_duration - self.overlap_size) : (ii + 1) * (self.pixel_chunk_duration - self.overlap_size) + self.pixel_chunk_duration, ] for ii in range(num_windows) ] latent = self._impl_encode(torch.cat(pack_list, dim=0)) latent = rearrange(latent, "(n b) c t h w -> n b c t h w", b=B) # Calculate the overlap size in the latent space, accounting for any temporal compression # For example, if the network downsamples temporally by a factor of 4, adjust the overlap accordingly overlap_latent = (self.overlap_size - 1) // self.temporal_compression_factor + 1 # Concatenate the latent representations from each chunk/window # For the first chunk, include all latent frames # For subsequent chunks, exclude the overlapping latent frames at the beginning out = torch.cat([latent[0]] + [latent[i, :, :, overlap_latent:] for i in range(1, len(latent))], dim=2) return out @torch.no_grad() def maybe_pad_latent(self, latent: torch.Tensor) -> tuple[torch.Tensor, int]: """Since the decoder expect the latent to be window_size + (window_size - decode_overlap_size) * N, we need to pad the latent to match the expected size Args: latent (torch.Tensor): [B, C, T, H, W] Returns: latent: torch.Tensor, the padded latent padding_t: int, the number of padding latent t """ # Calculate the overlap size and window size in the latent space, considering any temporal compression decode_overlap_size = (self.overlap_size - 1) // self.temporal_compression_factor + 1 # Calculate the number of windows/chunks for decoding window_size = (self.pixel_chunk_duration - 1) // self.temporal_compression_factor + 1 B, C, current_latent_t, H, W = latent.shape if current_latent_t < window_size: # If the current latent tensor is smaller than the window size, pad it to the window size target_latent_t = window_size else: # Calculate the target latent frame number for decoding target_latent_t = window_size + math.ceil( (current_latent_t - window_size) / (window_size - decode_overlap_size) ) * (window_size - decode_overlap_size) padding_t = target_latent_t - current_latent_t if padding_t != 0: log.info( f"Padding latent from {current_latent_t} to {target_latent_t} for decoding purpose. current window_size: {window_size}, decode_overlap_size: {decode_overlap_size}" ) padding = latent.new_zeros(B, C, padding_t, H, W) latent = torch.cat([latent, padding], dim=2).contiguous() return latent, padding_t @torch.no_grad() def decode(self, state: torch.Tensor) -> torch.Tensor: state, padding_t = self.maybe_pad_latent(state) B, C, num_latents, H, W = state.shape # Calculate the overlap size and window size in the latent space, considering any temporal compression decode_overlap_size = (self.overlap_size - 1) // self.temporal_compression_factor + 1 # Calculate the number of windows/chunks for decoding window_size = (self.pixel_chunk_duration - 1) // self.temporal_compression_factor + 1 num_windows = (num_latents - window_size) // (window_size - decode_overlap_size) + 1 decoded_frames = [] # Start decoding with the initial window of latent frames current_state = state[:, :, :window_size] for i in range(num_windows): # Decode the current window to get the reconstructed frames window_frames = super().decode(current_state) decoded_frames.append(window_frames) # Re-encode the overlapping frames at the end of the decoded window to obtain the last latent frame # This is necessary due to the casual first frame design last_latent = self._impl_encode(window_frames[:, :, -self.overlap_size : -self.overlap_size + 1])[:, :, 0:1] # Calculate the start and end indices for the next chunk of latent frames start_idx = window_size + i * (window_size - decode_overlap_size) - decode_overlap_size + 1 end_idx = start_idx + window_size - 1 # Prepare the next state by concatenating the last latent frame with the next chunk of latent frames current_state = torch.cat([last_latent, state[:, :, start_idx:end_idx]], dim=2) # Remove overlapping frames (e.g., 17 frames) from all windows except the first one. for i in range(1, num_windows): decoded_frames[i] = decoded_frames[i][:, :, self.overlap_size :] video_tensor = torch.cat(decoded_frames, dim=2) return video_tensor @property def is_chunk_overlap(self): return True class DebugMeanStdVideoJITVAE(VideoJITTokenizer): """ A class for one """ def register_mean_std(self, mean_std_fp: str) -> None: target_shape = [1, self.latent_ch, 1, 1, 1] self.register_buffer( "latent_mean", # latent_mean.to(self.dtype).reshape(*target_shape), torch.zeros(*target_shape, dtype=self.dtype), persistent=False, ) self.register_buffer( "latent_std", torch.ones(*target_shape, dtype=self.dtype), persistent=False, ) @torch.no_grad() def encode(self, state: torch.Tensor) -> torch.Tensor: B, C, T, H, W = state.shape if T == 1: return JITVAE.encode(self, state) return super().encode(state) @torch.no_grad() def decode(self, latent: torch.Tensor) -> torch.Tensor: B, _, T, _, _ = latent.shape if T == 1: return JITVAE.decode(self, latent) return super().decode(latent) class DebugMeanStdVideoJITVAEChunkWiseTokenizer(VideoJITVAEChunkWiseTokenizer): def register_mean_std(self, mean_std_fp: str) -> None: target_shape = [1, self.latent_ch, 1, 1, 1] self.register_buffer( "latent_mean", # latent_mean.to(self.dtype).reshape(*target_shape), torch.zeros(*target_shape, dtype=self.dtype), persistent=False, ) self.register_buffer( "latent_std", torch.ones(*target_shape, dtype=self.dtype), persistent=False, ) @torch.no_grad() def encode(self, state: torch.Tensor) -> torch.Tensor: B, C, T, H, W = state.shape if T == 1: return JITVAE.encode(self, state) return super().encode(state) @torch.no_grad() def decode(self, latent: torch.Tensor) -> torch.Tensor: B, _, T, _, _ = latent.shape if T == 1: return JITVAE.decode(self, latent) return super().decode(latent) class JointImageVideoTokenizer(BaseVAE, VideoTokenizerInterface): def __init__( self, image_vae: torch.nn.Module, video_vae: torch.nn.Module, name: str, latent_ch: int = 16, squeeze_for_image: bool = True, ): super().__init__(latent_ch, name) self.image_vae = image_vae self.video_vae = video_vae self.squeeze_for_image = squeeze_for_image def encode_image(self, state: torch.Tensor) -> torch.Tensor: if self.squeeze_for_image: return self.image_vae.encode(state.squeeze(2)).unsqueeze(2) return self.image_vae.encode(state) def decode_image(self, latent: torch.Tensor) -> torch.Tensor: if self.squeeze_for_image: return self.image_vae.decode(latent.squeeze(2)).unsqueeze(2) return self.image_vae.decode(latent) @torch.no_grad() def encode(self, state: torch.Tensor) -> torch.Tensor: B, C, T, H, W = state.shape if T == 1: return self.encode_image(state) return self.video_vae.encode(state) @torch.no_grad() def decode(self, latent: torch.Tensor) -> torch.Tensor: B, C, T, H, W = latent.shape if T == 1: return self.decode_image(latent) return self.video_vae.decode(latent) def reset_dtype(self, *args, **kwargs): """ Resets the data type of the encoder and decoder to the model's default data type. Args: *args, **kwargs: Unused, present to allow flexibility in method calls. """ del args, kwargs self.image_vae.reset_dtype() self.video_vae.reset_dtype() def get_latent_num_frames(self, num_pixel_frames: int) -> int: if num_pixel_frames == 1: return 1 return self.video_vae.get_latent_num_frames(num_pixel_frames) def get_pixel_num_frames(self, num_latent_frames: int) -> int: if num_latent_frames == 1: return 1 return self.video_vae.get_pixel_num_frames(num_latent_frames) @property def spatial_compression_factor(self): return self.video_vae.spatial_compression_factor @property def temporal_compression_factor(self): return self.video_vae.temporal_compression_factor @property def spatial_resolution(self) -> str: return self.video_vae.spatial_resolution @property def pixel_chunk_duration(self) -> int: return self.video_vae.pixel_chunk_duration @property def latent_chunk_duration(self) -> int: return self.video_vae.latent_chunk_duration class JointImageVideoSharedJITTokenizer(JointImageVideoTokenizer): """ First version of the ImageVideoVAE trained with Fitsum. We have to use seperate mean and std for image and video due to non-causal nature of the model. """ def __init__(self, image_vae: Module, video_vae: Module, name: str, latent_ch: int = 16): super().__init__(image_vae, video_vae, name, latent_ch, squeeze_for_image=False) assert isinstance(image_vae, JITVAE) assert isinstance( video_vae, VideoJITTokenizer ), f"video_vae should be an instance of VideoJITVAE, got {type(video_vae)}" # a hack to make the image_vae and video_vae share the same encoder and decoder self.image_vae.encoder = self.video_vae.encoder self.image_vae.decoder = self.video_vae.decoder class JointImageVideoStateDictTokenizer(JointImageVideoTokenizer): """ Copy of ImageVideoVAE1 that uses plain torch.nn.Module instead of JITed one so that it can be used witch torch.compile() """ def __init__(self, image_vae: Module, video_vae: Module, name: str, latent_ch: int = 16): super().__init__(image_vae, video_vae, name, latent_ch, squeeze_for_image=False) assert isinstance(image_vae, StateDictVAE) assert isinstance(video_vae, VideoStateDictTokenizer) # a hack to make the image_vae and video_vae share the same encoder and decoder # nn.Module del self.image_vae.vae # Just method del self.image_vae.encoder # Just method del self.image_vae.decoder self.image_vae.vae = self.video_vae.vae self.image_vae.encoder = self.video_vae.encoder self.image_vae.decoder = self.video_vae.decoder class DummyJointImageVideoTokenizer(BaseVAE, VideoTokenizerInterface): def __init__( self, name: str = "dummy_joint_image_video", pixel_ch: int = 3, latent_ch: int = 16, pixel_chunk_duration: int = 17, latent_chunk_duration: int = 3, spatial_compression_factor: int = 16, temporal_compression_factor: int = 8, spatial_resolution: str = "720", ): self.pixel_ch = pixel_ch self._pixel_chunk_duration = pixel_chunk_duration self._latent_chunk_duration = latent_chunk_duration self._spatial_compression_factor = spatial_compression_factor self._temporal_compression_factor = temporal_compression_factor self._spatial_resolution = spatial_resolution super().__init__(latent_ch, name) @property def spatial_compression_factor(self): return self._spatial_compression_factor @property def temporal_compression_factor(self): return self._temporal_compression_factor @property def spatial_resolution(self) -> str: return self._spatial_resolution @property def pixel_chunk_duration(self) -> int: return self._pixel_chunk_duration @property def latent_chunk_duration(self) -> int: return self._latent_chunk_duration def get_latent_num_frames(self, num_pixel_frames: int) -> int: if num_pixel_frames == 1: return 1 assert ( num_pixel_frames % self.pixel_chunk_duration == 0 ), f"Temporal dimension {num_pixel_frames} is not divisible by chunk_length {self.pixel_chunk_duration}" return num_pixel_frames // self.pixel_chunk_duration * self.latent_chunk_duration def get_pixel_num_frames(self, num_latent_frames: int) -> int: if num_latent_frames == 1: return 1 assert ( num_latent_frames % self.latent_chunk_duration == 0 ), f"Temporal dimension {num_latent_frames} is not divisible by chunk_length {self.latent_chunk_duration}" return num_latent_frames // self.latent_chunk_duration * self.pixel_chunk_duration def encode(self, state: torch.Tensor) -> torch.Tensor: B, C, T, H, W = state.shape if T == 1: state_B_T_C_H_W = F.interpolate( rearrange(state, "b c t h w -> b t c h w"), size=(self.latent_ch, H // self.spatial_compression_factor, W // self.spatial_compression_factor), mode="trilinear", align_corners=False, ) return rearrange(state_B_T_C_H_W, "b t c h w -> b c t h w").contiguous() assert ( T % self.pixel_chunk_duration == 0 ), f"Temporal dimension {T} is not divisible by chunk_length {self.pixel_chunk_duration}" num_frames = T // self.pixel_chunk_duration * self.latent_chunk_duration state_B_C_T_H_W = F.interpolate( state, size=(self.latent_ch, H // self.spatial_compression_factor, W // self.spatial_compression_factor), mode="trilinear", align_corners=False, ) state_B_H_W_T_C = rearrange(state_B_C_T_H_W, "b c t h w -> b h w t c") state_B_H_W_T_C = F.interpolate( state_B_H_W_T_C, size=(W // self.spatial_compression_factor, num_frames, self.latent_ch), mode="trilinear", align_corners=False, ) return rearrange(state_B_H_W_T_C, "b h w t c -> b c t h w").contiguous() def decode(self, latent: torch.Tensor) -> torch.Tensor: B, C, T, H, W = latent.shape if T == 1: latent_B_T_C_H_W = F.interpolate( rearrange(latent, "b c t h w -> b t c h w"), size=(self.pixel_ch, H * self.spatial_compression_factor, W * self.spatial_compression_factor), mode="trilinear", align_corners=False, ) return rearrange(latent_B_T_C_H_W, "b t c h w -> b c t h w").contiguous() assert ( T % self.latent_chunk_duration == 0 ), f"Temporal dimension {T} is not divisible by chunk_length {self.latent_chunk_duration}" num_frames = T * self.pixel_chunk_duration // self.latent_chunk_duration latent_B_H_W_T_C = rearrange(latent, "b c t h w -> b h w t c") latent_B_H_W_T_C = F.interpolate( latent_B_H_W_T_C, size=(W * self.spatial_compression_factor, num_frames, self.pixel_ch), mode="trilinear", align_corners=False, ) latent_B_C_T_H_W = rearrange(latent_B_H_W_T_C, "b h w t c -> b c t h w") state = F.interpolate( latent_B_C_T_H_W, size=(num_frames, H * self.spatial_compression_factor, W * self.spatial_compression_factor), mode="trilinear", align_corners=False, ) return state.contiguous()