Add cogvideox_vae.py

cogvideox_vae.py

@@ -0,0 +1,1675 @@
+# Copyright 2024 The CogVideoX team, Tsinghua University & ZhipuAI and The HuggingFace Team.
+# All rights reserved.
+#
+# 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.
+
+from typing import Dict, Optional, Tuple, Union
+
+import numpy as np
+import torch
+import torch.nn as nn
+import torch.nn.functional as F
+import json
+import os
+
+from diffusers.configuration_utils import ConfigMixin, register_to_config
+from diffusers.loaders.single_file_model import FromOriginalModelMixin
+from diffusers.utils import logging
+from diffusers.utils.accelerate_utils import apply_forward_hook
+from diffusers.models.activations import get_activation
+from diffusers.models.downsampling import CogVideoXDownsample3D
+from diffusers.models.modeling_outputs import AutoencoderKLOutput
+from diffusers.models.modeling_utils import ModelMixin
+from diffusers.models.upsampling import CogVideoXUpsample3D
+from diffusers.models.autoencoders.vae import DecoderOutput, DiagonalGaussianDistribution
+
+
+logger = logging.get_logger(__name__)  # pylint: disable=invalid-name
+
+
+class CogVideoXSafeConv3d(nn.Conv3d):
+    r"""
+    A 3D convolution layer that splits the input tensor into smaller parts to avoid OOM in CogVideoX Model.
+    """
+
+    def forward(self, input: torch.Tensor) -> torch.Tensor:
+        memory_count = (
+            (input.shape[0] * input.shape[1] * input.shape[2] * input.shape[3] * input.shape[4]) * 2 / 1024**3
+        )
+
+        # Set to 2GB, suitable for CuDNN
+        if memory_count > 2:
+            kernel_size = self.kernel_size[0]
+            part_num = int(memory_count / 2) + 1
+            input_chunks = torch.chunk(input, part_num, dim=2)
+
+            if kernel_size > 1:
+                input_chunks = [input_chunks[0]] + [
+                    torch.cat((input_chunks[i - 1][:, :, -kernel_size + 1 :], input_chunks[i]), dim=2)
+                    for i in range(1, len(input_chunks))
+                ]
+
+            output_chunks = []
+            for input_chunk in input_chunks:
+                output_chunks.append(super().forward(input_chunk))
+            output = torch.cat(output_chunks, dim=2)
+            return output
+        else:
+            return super().forward(input)
+
+
+class CogVideoXCausalConv3d(nn.Module):
+    r"""A 3D causal convolution layer that pads the input tensor to ensure causality in CogVideoX Model.
+
+    Args:
+        in_channels (`int`): Number of channels in the input tensor.
+        out_channels (`int`): Number of output channels produced by the convolution.
+        kernel_size (`int` or `Tuple[int, int, int]`): Kernel size of the convolutional kernel.
+        stride (`int`, defaults to `1`): Stride of the convolution.
+        dilation (`int`, defaults to `1`): Dilation rate of the convolution.
+        pad_mode (`str`, defaults to `"constant"`): Padding mode.
+    """
+
+    def __init__(
+        self,
+        in_channels: int,
+        out_channels: int,
+        kernel_size: Union[int, Tuple[int, int, int]],
+        stride: int = 1,
+        dilation: int = 1,
+        pad_mode: str = "constant",
+    ):
+        super().__init__()
+
+        if isinstance(kernel_size, int):
+            kernel_size = (kernel_size,) * 3
+
+        time_kernel_size, height_kernel_size, width_kernel_size = kernel_size
+
+        # TODO(aryan): configure calculation based on stride and dilation in the future.
+        # Since CogVideoX does not use it, it is currently tailored to "just work" with Mochi
+        time_pad = time_kernel_size - 1
+        height_pad = (height_kernel_size - 1) // 2
+        width_pad = (width_kernel_size - 1) // 2
+
+        self.pad_mode = pad_mode
+        self.height_pad = height_pad
+        self.width_pad = width_pad
+        self.time_pad = time_pad
+        self.time_causal_padding = (width_pad, width_pad, height_pad, height_pad, time_pad, 0)
+
+        self.temporal_dim = 2
+        self.time_kernel_size = time_kernel_size
+
+        stride = stride if isinstance(stride, tuple) else (stride, 1, 1)
+        dilation = (dilation, 1, 1)
+        self.conv = CogVideoXSafeConv3d(
+            in_channels=in_channels,
+            out_channels=out_channels,
+            kernel_size=kernel_size,
+            stride=stride,
+            dilation=dilation,
+        )
+
+    def fake_context_parallel_forward(
+        self, inputs: torch.Tensor, conv_cache: Optional[torch.Tensor] = None
+    ) -> torch.Tensor:
+        if self.pad_mode == "replicate":
+            inputs = F.pad(inputs, self.time_causal_padding, mode="replicate")
+        else:
+            kernel_size = self.time_kernel_size
+            if kernel_size > 1:
+                cached_inputs = [conv_cache] if conv_cache is not None else [inputs[:, :, :1]] * (kernel_size - 1)
+                inputs = torch.cat(cached_inputs + [inputs], dim=2)
+        return inputs
+
+    def forward(self, inputs: torch.Tensor, conv_cache: Optional[torch.Tensor] = None) -> torch.Tensor:
+        inputs = self.fake_context_parallel_forward(inputs, conv_cache)
+
+        if self.pad_mode == "replicate":
+            conv_cache = None
+        else:
+            padding_2d = (self.width_pad, self.width_pad, self.height_pad, self.height_pad)
+            conv_cache = inputs[:, :, -self.time_kernel_size + 1 :].clone()
+            inputs = F.pad(inputs, padding_2d, mode="constant", value=0)
+
+        output = self.conv(inputs)
+        return output, conv_cache
+
+
+class CogVideoXSpatialNorm3D(nn.Module):
+    r"""
+    Spatially conditioned normalization as defined in https://arxiv.org/abs/2209.09002. This implementation is specific
+    to 3D-video like data.
+
+    CogVideoXSafeConv3d is used instead of nn.Conv3d to avoid OOM in CogVideoX Model.
+
+    Args:
+        f_channels (`int`):
+            The number of channels for input to group normalization layer, and output of the spatial norm layer.
+        zq_channels (`int`):
+            The number of channels for the quantized vector as described in the paper.
+        groups (`int`):
+            Number of groups to separate the channels into for group normalization.
+    """
+
+    def __init__(
+        self,
+        f_channels: int,
+        zq_channels: int,
+        groups: int = 32,
+    ):
+        super().__init__()
+        self.norm_layer = nn.GroupNorm(num_channels=f_channels, num_groups=groups, eps=1e-6, affine=True)
+        self.conv_y = CogVideoXCausalConv3d(zq_channels, f_channels, kernel_size=1, stride=1)
+        self.conv_b = CogVideoXCausalConv3d(zq_channels, f_channels, kernel_size=1, stride=1)
+
+    def forward(
+        self, f: torch.Tensor, zq: torch.Tensor, conv_cache: Optional[Dict[str, torch.Tensor]] = None
+    ) -> torch.Tensor:
+        new_conv_cache = {}
+        conv_cache = conv_cache or {}
+
+        if f.shape[2] > 1 and f.shape[2] % 2 == 1:
+            f_first, f_rest = f[:, :, :1], f[:, :, 1:]
+            f_first_size, f_rest_size = f_first.shape[-3:], f_rest.shape[-3:]
+            z_first, z_rest = zq[:, :, :1], zq[:, :, 1:]
+            z_first = F.interpolate(z_first, size=f_first_size)
+            z_rest = F.interpolate(z_rest, size=f_rest_size)
+            zq = torch.cat([z_first, z_rest], dim=2)
+        else:
+            zq = F.interpolate(zq, size=f.shape[-3:])
+
+        conv_y, new_conv_cache["conv_y"] = self.conv_y(zq, conv_cache=conv_cache.get("conv_y"))
+        conv_b, new_conv_cache["conv_b"] = self.conv_b(zq, conv_cache=conv_cache.get("conv_b"))
+
+        norm_f = self.norm_layer(f)
+        new_f = norm_f * conv_y + conv_b
+        return new_f, new_conv_cache
+
+
+class CogVideoXUpsample3D(nn.Module):
+    r"""
+    A 3D Upsample layer using in CogVideoX by Tsinghua University & ZhipuAI # Todo: Wait for paper relase.
+
+    Args:
+        in_channels (`int`):
+            Number of channels in the input image.
+        out_channels (`int`):
+            Number of channels produced by the convolution.
+        kernel_size (`int`, defaults to `3`):
+            Size of the convolving kernel.
+        stride (`int`, defaults to `1`):
+            Stride of the convolution.
+        padding (`int`, defaults to `1`):
+            Padding added to all four sides of the input.
+        compress_time (`bool`, defaults to `False`):
+            Whether or not to compress the time dimension.
+    """
+
+    def __init__(
+        self,
+        in_channels: int,
+        out_channels: int,
+        kernel_size: int = 3,
+        stride: int = 1,
+        padding: int = 1,
+        compress_time: bool = False,
+    ) -> None:
+        super().__init__()
+
+        self.conv = nn.Conv2d(in_channels, out_channels, kernel_size=kernel_size, stride=stride, padding=padding)
+        self.compress_time = compress_time
+        
+        self.auto_split_process = True
+        self.first_frame_flag = False
+
+    def forward(self, inputs: torch.Tensor) -> torch.Tensor:
+        if self.compress_time:
+            if self.auto_split_process:
+                if inputs.shape[2] > 1 and inputs.shape[2] % 2 == 1:
+                    # split first frame
+                    x_first, x_rest = inputs[:, :, 0], inputs[:, :, 1:]
+
+                    x_first = F.interpolate(x_first, scale_factor=2.0)
+                    x_rest = F.interpolate(x_rest, scale_factor=2.0)
+                    x_first = x_first[:, :, None, :, :]
+                    inputs = torch.cat([x_first, x_rest], dim=2)
+                elif inputs.shape[2] > 1:
+                    inputs = F.interpolate(inputs, scale_factor=2.0)
+                else:
+                    inputs = inputs.squeeze(2)
+                    inputs = F.interpolate(inputs, scale_factor=2.0)
+                    inputs = inputs[:, :, None, :, :]
+            else:
+                if self.first_frame_flag:
+                    inputs = inputs.squeeze(2)
+                    inputs = F.interpolate(inputs, scale_factor=2.0)
+                    inputs = inputs[:, :, None, :, :]
+                else:
+                    inputs = F.interpolate(inputs, scale_factor=2.0)
+        else:
+            # only interpolate 2D
+            b, c, t, h, w = inputs.shape
+            inputs = inputs.permute(0, 2, 1, 3, 4).reshape(b * t, c, h, w)
+            inputs = F.interpolate(inputs, scale_factor=2.0)
+            inputs = inputs.reshape(b, t, c, *inputs.shape[2:]).permute(0, 2, 1, 3, 4)
+
+        b, c, t, h, w = inputs.shape
+        inputs = inputs.permute(0, 2, 1, 3, 4).reshape(b * t, c, h, w)
+        inputs = self.conv(inputs)
+        inputs = inputs.reshape(b, t, *inputs.shape[1:]).permute(0, 2, 1, 3, 4)
+
+        return inputs
+
+
+class CogVideoXResnetBlock3D(nn.Module):
+    r"""
+    A 3D ResNet block used in the CogVideoX model.
+
+    Args:
+        in_channels (`int`):
+            Number of input channels.
+        out_channels (`int`, *optional*):
+            Number of output channels. If None, defaults to `in_channels`.
+        dropout (`float`, defaults to `0.0`):
+            Dropout rate.
+        temb_channels (`int`, defaults to `512`):
+            Number of time embedding channels.
+        groups (`int`, defaults to `32`):
+            Number of groups to separate the channels into for group normalization.
+        eps (`float`, defaults to `1e-6`):
+            Epsilon value for normalization layers.
+        non_linearity (`str`, defaults to `"swish"`):
+            Activation function to use.
+        conv_shortcut (bool, defaults to `False`):
+            Whether or not to use a convolution shortcut.
+        spatial_norm_dim (`int`, *optional*):
+            The dimension to use for spatial norm if it is to be used instead of group norm.
+        pad_mode (str, defaults to `"first"`):
+            Padding mode.
+    """
+
+    def __init__(
+        self,
+        in_channels: int,
+        out_channels: Optional[int] = None,
+        dropout: float = 0.0,
+        temb_channels: int = 512,
+        groups: int = 32,
+        eps: float = 1e-6,
+        non_linearity: str = "swish",
+        conv_shortcut: bool = False,
+        spatial_norm_dim: Optional[int] = None,
+        pad_mode: str = "first",
+    ):
+        super().__init__()
+
+        out_channels = out_channels or in_channels
+
+        self.in_channels = in_channels
+        self.out_channels = out_channels
+        self.nonlinearity = get_activation(non_linearity)
+        self.use_conv_shortcut = conv_shortcut
+        self.spatial_norm_dim = spatial_norm_dim
+
+        if spatial_norm_dim is None:
+            self.norm1 = nn.GroupNorm(num_channels=in_channels, num_groups=groups, eps=eps)
+            self.norm2 = nn.GroupNorm(num_channels=out_channels, num_groups=groups, eps=eps)
+        else:
+            self.norm1 = CogVideoXSpatialNorm3D(
+                f_channels=in_channels,
+                zq_channels=spatial_norm_dim,
+                groups=groups,
+            )
+            self.norm2 = CogVideoXSpatialNorm3D(
+                f_channels=out_channels,
+                zq_channels=spatial_norm_dim,
+                groups=groups,
+            )
+
+        self.conv1 = CogVideoXCausalConv3d(
+            in_channels=in_channels, out_channels=out_channels, kernel_size=3, pad_mode=pad_mode
+        )
+
+        if temb_channels > 0:
+            self.temb_proj = nn.Linear(in_features=temb_channels, out_features=out_channels)
+
+        self.dropout = nn.Dropout(dropout)
+        self.conv2 = CogVideoXCausalConv3d(
+            in_channels=out_channels, out_channels=out_channels, kernel_size=3, pad_mode=pad_mode
+        )
+
+        if self.in_channels != self.out_channels:
+            if self.use_conv_shortcut:
+                self.conv_shortcut = CogVideoXCausalConv3d(
+                    in_channels=in_channels, out_channels=out_channels, kernel_size=3, pad_mode=pad_mode
+                )
+            else:
+                self.conv_shortcut = CogVideoXSafeConv3d(
+                    in_channels=in_channels, out_channels=out_channels, kernel_size=1, stride=1, padding=0
+                )
+
+    def forward(
+        self,
+        inputs: torch.Tensor,
+        temb: Optional[torch.Tensor] = None,
+        zq: Optional[torch.Tensor] = None,
+        conv_cache: Optional[Dict[str, torch.Tensor]] = None,
+    ) -> torch.Tensor:
+        new_conv_cache = {}
+        conv_cache = conv_cache or {}
+
+        hidden_states = inputs
+
+        if zq is not None:
+            hidden_states, new_conv_cache["norm1"] = self.norm1(hidden_states, zq, conv_cache=conv_cache.get("norm1"))
+        else:
+            hidden_states = self.norm1(hidden_states)
+
+        hidden_states = self.nonlinearity(hidden_states)
+        hidden_states, new_conv_cache["conv1"] = self.conv1(hidden_states, conv_cache=conv_cache.get("conv1"))
+
+        if temb is not None:
+            hidden_states = hidden_states + self.temb_proj(self.nonlinearity(temb))[:, :, None, None, None]
+
+        if zq is not None:
+            hidden_states, new_conv_cache["norm2"] = self.norm2(hidden_states, zq, conv_cache=conv_cache.get("norm2"))
+        else:
+            hidden_states = self.norm2(hidden_states)
+
+        hidden_states = self.nonlinearity(hidden_states)
+        hidden_states = self.dropout(hidden_states)
+        hidden_states, new_conv_cache["conv2"] = self.conv2(hidden_states, conv_cache=conv_cache.get("conv2"))
+
+        if self.in_channels != self.out_channels:
+            if self.use_conv_shortcut:
+                inputs, new_conv_cache["conv_shortcut"] = self.conv_shortcut(
+                    inputs, conv_cache=conv_cache.get("conv_shortcut")
+                )
+            else:
+                inputs = self.conv_shortcut(inputs)
+
+        hidden_states = hidden_states + inputs
+        return hidden_states, new_conv_cache
+
+
+class CogVideoXDownBlock3D(nn.Module):
+    r"""
+    A downsampling block used in the CogVideoX model.
+
+    Args:
+        in_channels (`int`):
+            Number of input channels.
+        out_channels (`int`, *optional*):
+            Number of output channels. If None, defaults to `in_channels`.
+        temb_channels (`int`, defaults to `512`):
+            Number of time embedding channels.
+        num_layers (`int`, defaults to `1`):
+            Number of resnet layers.
+        dropout (`float`, defaults to `0.0`):
+            Dropout rate.
+        resnet_eps (`float`, defaults to `1e-6`):
+            Epsilon value for normalization layers.
+        resnet_act_fn (`str`, defaults to `"swish"`):
+            Activation function to use.
+        resnet_groups (`int`, defaults to `32`):
+            Number of groups to separate the channels into for group normalization.
+        add_downsample (`bool`, defaults to `True`):
+            Whether or not to use a downsampling layer. If not used, output dimension would be same as input dimension.
+        compress_time (`bool`, defaults to `False`):
+            Whether or not to downsample across temporal dimension.
+        pad_mode (str, defaults to `"first"`):
+            Padding mode.
+    """
+
+    _supports_gradient_checkpointing = True
+
+    def __init__(
+        self,
+        in_channels: int,
+        out_channels: int,
+        temb_channels: int,
+        dropout: float = 0.0,
+        num_layers: int = 1,
+        resnet_eps: float = 1e-6,
+        resnet_act_fn: str = "swish",
+        resnet_groups: int = 32,
+        add_downsample: bool = True,
+        downsample_padding: int = 0,
+        compress_time: bool = False,
+        pad_mode: str = "first",
+    ):
+        super().__init__()
+
+        resnets = []
+        for i in range(num_layers):
+            in_channel = in_channels if i == 0 else out_channels
+            resnets.append(
+                CogVideoXResnetBlock3D(
+                    in_channels=in_channel,
+                    out_channels=out_channels,
+                    dropout=dropout,
+                    temb_channels=temb_channels,
+                    groups=resnet_groups,
+                    eps=resnet_eps,
+                    non_linearity=resnet_act_fn,
+                    pad_mode=pad_mode,
+                )
+            )
+
+        self.resnets = nn.ModuleList(resnets)
+        self.downsamplers = None
+
+        if add_downsample:
+            self.downsamplers = nn.ModuleList(
+                [
+                    CogVideoXDownsample3D(
+                        out_channels, out_channels, padding=downsample_padding, compress_time=compress_time
+                    )
+                ]
+            )
+
+        self.gradient_checkpointing = False
+
+    def forward(
+        self,
+        hidden_states: torch.Tensor,
+        temb: Optional[torch.Tensor] = None,
+        zq: Optional[torch.Tensor] = None,
+        conv_cache: Optional[Dict[str, torch.Tensor]] = None,
+    ) -> torch.Tensor:
+        r"""Forward method of the `CogVideoXDownBlock3D` class."""
+
+        new_conv_cache = {}
+        conv_cache = conv_cache or {}
+
+        for i, resnet in enumerate(self.resnets):
+            conv_cache_key = f"resnet_{i}"
+
+            if torch.is_grad_enabled() and self.gradient_checkpointing:
+
+                def create_custom_forward(module):
+                    def create_forward(*inputs):
+                        return module(*inputs)
+
+                    return create_forward
+
+                hidden_states, new_conv_cache[conv_cache_key] = torch.utils.checkpoint.checkpoint(
+                    create_custom_forward(resnet),
+                    hidden_states,
+                    temb,
+                    zq,
+                    conv_cache.get(conv_cache_key),
+                )
+            else:
+                hidden_states, new_conv_cache[conv_cache_key] = resnet(
+                    hidden_states, temb, zq, conv_cache=conv_cache.get(conv_cache_key)
+                )
+
+        if self.downsamplers is not None:
+            for downsampler in self.downsamplers:
+                hidden_states = downsampler(hidden_states)
+
+        return hidden_states, new_conv_cache
+
+
+class CogVideoXMidBlock3D(nn.Module):
+    r"""
+    A middle block used in the CogVideoX model.
+
+    Args:
+        in_channels (`int`):
+            Number of input channels.
+        temb_channels (`int`, defaults to `512`):
+            Number of time embedding channels.
+        dropout (`float`, defaults to `0.0`):
+            Dropout rate.
+        num_layers (`int`, defaults to `1`):
+            Number of resnet layers.
+        resnet_eps (`float`, defaults to `1e-6`):
+            Epsilon value for normalization layers.
+        resnet_act_fn (`str`, defaults to `"swish"`):
+            Activation function to use.
+        resnet_groups (`int`, defaults to `32`):
+            Number of groups to separate the channels into for group normalization.
+        spatial_norm_dim (`int`, *optional*):
+            The dimension to use for spatial norm if it is to be used instead of group norm.
+        pad_mode (str, defaults to `"first"`):
+            Padding mode.
+    """
+
+    _supports_gradient_checkpointing = True
+
+    def __init__(
+        self,
+        in_channels: int,
+        temb_channels: int,
+        dropout: float = 0.0,
+        num_layers: int = 1,
+        resnet_eps: float = 1e-6,
+        resnet_act_fn: str = "swish",
+        resnet_groups: int = 32,
+        spatial_norm_dim: Optional[int] = None,
+        pad_mode: str = "first",
+    ):
+        super().__init__()
+
+        resnets = []
+        for _ in range(num_layers):
+            resnets.append(
+                CogVideoXResnetBlock3D(
+                    in_channels=in_channels,
+                    out_channels=in_channels,
+                    dropout=dropout,
+                    temb_channels=temb_channels,
+                    groups=resnet_groups,
+                    eps=resnet_eps,
+                    spatial_norm_dim=spatial_norm_dim,
+                    non_linearity=resnet_act_fn,
+                    pad_mode=pad_mode,
+                )
+            )
+        self.resnets = nn.ModuleList(resnets)
+
+        self.gradient_checkpointing = False
+
+    def forward(
+        self,
+        hidden_states: torch.Tensor,
+        temb: Optional[torch.Tensor] = None,
+        zq: Optional[torch.Tensor] = None,
+        conv_cache: Optional[Dict[str, torch.Tensor]] = None,
+    ) -> torch.Tensor:
+        r"""Forward method of the `CogVideoXMidBlock3D` class."""
+
+        new_conv_cache = {}
+        conv_cache = conv_cache or {}
+
+        for i, resnet in enumerate(self.resnets):
+            conv_cache_key = f"resnet_{i}"
+
+            if torch.is_grad_enabled() and self.gradient_checkpointing:
+
+                def create_custom_forward(module):
+                    def create_forward(*inputs):
+                        return module(*inputs)
+
+                    return create_forward
+
+                hidden_states, new_conv_cache[conv_cache_key] = torch.utils.checkpoint.checkpoint(
+                    create_custom_forward(resnet), hidden_states, temb, zq, conv_cache.get(conv_cache_key)
+                )
+            else:
+                hidden_states, new_conv_cache[conv_cache_key] = resnet(
+                    hidden_states, temb, zq, conv_cache=conv_cache.get(conv_cache_key)
+                )
+
+        return hidden_states, new_conv_cache
+
+
+class CogVideoXUpBlock3D(nn.Module):
+    r"""
+    An upsampling block used in the CogVideoX model.
+
+    Args:
+        in_channels (`int`):
+            Number of input channels.
+        out_channels (`int`, *optional*):
+            Number of output channels. If None, defaults to `in_channels`.
+        temb_channels (`int`, defaults to `512`):
+            Number of time embedding channels.
+        dropout (`float`, defaults to `0.0`):
+            Dropout rate.
+        num_layers (`int`, defaults to `1`):
+            Number of resnet layers.
+        resnet_eps (`float`, defaults to `1e-6`):
+            Epsilon value for normalization layers.
+        resnet_act_fn (`str`, defaults to `"swish"`):
+            Activation function to use.
+        resnet_groups (`int`, defaults to `32`):
+            Number of groups to separate the channels into for group normalization.
+        spatial_norm_dim (`int`, defaults to `16`):
+            The dimension to use for spatial norm if it is to be used instead of group norm.
+        add_upsample (`bool`, defaults to `True`):
+            Whether or not to use a upsampling layer. If not used, output dimension would be same as input dimension.
+        compress_time (`bool`, defaults to `False`):
+            Whether or not to downsample across temporal dimension.
+        pad_mode (str, defaults to `"first"`):
+            Padding mode.
+    """
+
+    def __init__(
+        self,
+        in_channels: int,
+        out_channels: int,
+        temb_channels: int,
+        dropout: float = 0.0,
+        num_layers: int = 1,
+        resnet_eps: float = 1e-6,
+        resnet_act_fn: str = "swish",
+        resnet_groups: int = 32,
+        spatial_norm_dim: int = 16,
+        add_upsample: bool = True,
+        upsample_padding: int = 1,
+        compress_time: bool = False,
+        pad_mode: str = "first",
+    ):
+        super().__init__()
+
+        resnets = []
+        for i in range(num_layers):
+            in_channel = in_channels if i == 0 else out_channels
+            resnets.append(
+                CogVideoXResnetBlock3D(
+                    in_channels=in_channel,
+                    out_channels=out_channels,
+                    dropout=dropout,
+                    temb_channels=temb_channels,
+                    groups=resnet_groups,
+                    eps=resnet_eps,
+                    non_linearity=resnet_act_fn,
+                    spatial_norm_dim=spatial_norm_dim,
+                    pad_mode=pad_mode,
+                )
+            )
+
+        self.resnets = nn.ModuleList(resnets)
+        self.upsamplers = None
+
+        if add_upsample:
+            self.upsamplers = nn.ModuleList(
+                [
+                    CogVideoXUpsample3D(
+                        out_channels, out_channels, padding=upsample_padding, compress_time=compress_time
+                    )
+                ]
+            )
+
+        self.gradient_checkpointing = False
+
+    def forward(
+        self,
+        hidden_states: torch.Tensor,
+        temb: Optional[torch.Tensor] = None,
+        zq: Optional[torch.Tensor] = None,
+        conv_cache: Optional[Dict[str, torch.Tensor]] = None,
+    ) -> torch.Tensor:
+        r"""Forward method of the `CogVideoXUpBlock3D` class."""
+
+        new_conv_cache = {}
+        conv_cache = conv_cache or {}
+
+        for i, resnet in enumerate(self.resnets):
+            conv_cache_key = f"resnet_{i}"
+
+            if torch.is_grad_enabled() and self.gradient_checkpointing:
+
+                def create_custom_forward(module):
+                    def create_forward(*inputs):
+                        return module(*inputs)
+
+                    return create_forward
+
+                hidden_states, new_conv_cache[conv_cache_key] = torch.utils.checkpoint.checkpoint(
+                    create_custom_forward(resnet),
+                    hidden_states,
+                    temb,
+                    zq,
+                    conv_cache.get(conv_cache_key),
+                )
+            else:
+                hidden_states, new_conv_cache[conv_cache_key] = resnet(
+                    hidden_states, temb, zq, conv_cache=conv_cache.get(conv_cache_key)
+                )
+
+        if self.upsamplers is not None:
+            for upsampler in self.upsamplers:
+                hidden_states = upsampler(hidden_states)
+
+        return hidden_states, new_conv_cache
+
+
+class CogVideoXEncoder3D(nn.Module):
+    r"""
+    The `CogVideoXEncoder3D` layer of a variational autoencoder that encodes its input into a latent representation.
+
+    Args:
+        in_channels (`int`, *optional*, defaults to 3):
+            The number of input channels.
+        out_channels (`int`, *optional*, defaults to 3):
+            The number of output channels.
+        down_block_types (`Tuple[str, ...]`, *optional*, defaults to `("DownEncoderBlock2D",)`):
+            The types of down blocks to use. See `~diffusers.models.unet_2d_blocks.get_down_block` for available
+            options.
+        block_out_channels (`Tuple[int, ...]`, *optional*, defaults to `(64,)`):
+            The number of output channels for each block.
+        act_fn (`str`, *optional*, defaults to `"silu"`):
+            The activation function to use. See `~diffusers.models.activations.get_activation` for available options.
+        layers_per_block (`int`, *optional*, defaults to 2):
+            The number of layers per block.
+        norm_num_groups (`int`, *optional*, defaults to 32):
+            The number of groups for normalization.
+    """
+
+    _supports_gradient_checkpointing = True
+
+    def __init__(
+        self,
+        in_channels: int = 3,
+        out_channels: int = 16,
+        down_block_types: Tuple[str, ...] = (
+            "CogVideoXDownBlock3D",
+            "CogVideoXDownBlock3D",
+            "CogVideoXDownBlock3D",
+            "CogVideoXDownBlock3D",
+        ),
+        block_out_channels: Tuple[int, ...] = (128, 256, 256, 512),
+        layers_per_block: int = 3,
+        act_fn: str = "silu",
+        norm_eps: float = 1e-6,
+        norm_num_groups: int = 32,
+        dropout: float = 0.0,
+        pad_mode: str = "first",
+        temporal_compression_ratio: float = 4,
+    ):
+        super().__init__()
+
+        # log2 of temporal_compress_times
+        temporal_compress_level = int(np.log2(temporal_compression_ratio))
+
+        self.conv_in = CogVideoXCausalConv3d(in_channels, block_out_channels[0], kernel_size=3, pad_mode=pad_mode)
+        self.down_blocks = nn.ModuleList([])
+
+        # down blocks
+        output_channel = block_out_channels[0]
+        for i, down_block_type in enumerate(down_block_types):
+            input_channel = output_channel
+            output_channel = block_out_channels[i]
+            is_final_block = i == len(block_out_channels) - 1
+            compress_time = i < temporal_compress_level
+
+            if down_block_type == "CogVideoXDownBlock3D":
+                down_block = CogVideoXDownBlock3D(
+                    in_channels=input_channel,
+                    out_channels=output_channel,
+                    temb_channels=0,
+                    dropout=dropout,
+                    num_layers=layers_per_block,
+                    resnet_eps=norm_eps,
+                    resnet_act_fn=act_fn,
+                    resnet_groups=norm_num_groups,
+                    add_downsample=not is_final_block,
+                    compress_time=compress_time,
+                )
+            else:
+                raise ValueError("Invalid `down_block_type` encountered. Must be `CogVideoXDownBlock3D`")
+
+            self.down_blocks.append(down_block)
+
+        # mid block
+        self.mid_block = CogVideoXMidBlock3D(
+            in_channels=block_out_channels[-1],
+            temb_channels=0,
+            dropout=dropout,
+            num_layers=2,
+            resnet_eps=norm_eps,
+            resnet_act_fn=act_fn,
+            resnet_groups=norm_num_groups,
+            pad_mode=pad_mode,
+        )
+
+        self.norm_out = nn.GroupNorm(norm_num_groups, block_out_channels[-1], eps=1e-6)
+        self.conv_act = nn.SiLU()
+        self.conv_out = CogVideoXCausalConv3d(
+            block_out_channels[-1], 2 * out_channels, kernel_size=3, pad_mode=pad_mode
+        )
+
+        self.gradient_checkpointing = False
+
+    def forward(
+        self,
+        sample: torch.Tensor,
+        temb: Optional[torch.Tensor] = None,
+        conv_cache: Optional[Dict[str, torch.Tensor]] = None,
+    ) -> torch.Tensor:
+        r"""The forward method of the `CogVideoXEncoder3D` class."""
+
+        new_conv_cache = {}
+        conv_cache = conv_cache or {}
+
+        hidden_states, new_conv_cache["conv_in"] = self.conv_in(sample, conv_cache=conv_cache.get("conv_in"))
+
+        if torch.is_grad_enabled() and self.gradient_checkpointing:
+
+            def create_custom_forward(module):
+                def custom_forward(*inputs):
+                    return module(*inputs)
+
+                return custom_forward
+
+            # 1. Down
+            for i, down_block in enumerate(self.down_blocks):
+                conv_cache_key = f"down_block_{i}"
+                hidden_states, new_conv_cache[conv_cache_key] = torch.utils.checkpoint.checkpoint(
+                    create_custom_forward(down_block),
+                    hidden_states,
+                    temb,
+                    None,
+                    conv_cache.get(conv_cache_key),
+                )
+
+            # 2. Mid
+            hidden_states, new_conv_cache["mid_block"] = torch.utils.checkpoint.checkpoint(
+                create_custom_forward(self.mid_block),
+                hidden_states,
+                temb,
+                None,
+                conv_cache.get("mid_block"),
+            )
+        else:
+            # 1. Down
+            for i, down_block in enumerate(self.down_blocks):
+                conv_cache_key = f"down_block_{i}"
+                hidden_states, new_conv_cache[conv_cache_key] = down_block(
+                    hidden_states, temb, None, conv_cache=conv_cache.get(conv_cache_key)
+                )
+
+            # 2. Mid
+            hidden_states, new_conv_cache["mid_block"] = self.mid_block(
+                hidden_states, temb, None, conv_cache=conv_cache.get("mid_block")
+            )
+
+        # 3. Post-process
+        hidden_states = self.norm_out(hidden_states)
+        hidden_states = self.conv_act(hidden_states)
+
+        hidden_states, new_conv_cache["conv_out"] = self.conv_out(hidden_states, conv_cache=conv_cache.get("conv_out"))
+
+        return hidden_states, new_conv_cache
+
+
+class CogVideoXDecoder3D(nn.Module):
+    r"""
+    The `CogVideoXDecoder3D` layer of a variational autoencoder that decodes its latent representation into an output
+    sample.
+
+    Args:
+        in_channels (`int`, *optional*, defaults to 3):
+            The number of input channels.
+        out_channels (`int`, *optional*, defaults to 3):
+            The number of output channels.
+        up_block_types (`Tuple[str, ...]`, *optional*, defaults to `("UpDecoderBlock2D",)`):
+            The types of up blocks to use. See `~diffusers.models.unet_2d_blocks.get_up_block` for available options.
+        block_out_channels (`Tuple[int, ...]`, *optional*, defaults to `(64,)`):
+            The number of output channels for each block.
+        act_fn (`str`, *optional*, defaults to `"silu"`):
+            The activation function to use. See `~diffusers.models.activations.get_activation` for available options.
+        layers_per_block (`int`, *optional*, defaults to 2):
+            The number of layers per block.
+        norm_num_groups (`int`, *optional*, defaults to 32):
+            The number of groups for normalization.
+    """
+
+    _supports_gradient_checkpointing = True
+
+    def __init__(
+        self,
+        in_channels: int = 16,
+        out_channels: int = 3,
+        up_block_types: Tuple[str, ...] = (
+            "CogVideoXUpBlock3D",
+            "CogVideoXUpBlock3D",
+            "CogVideoXUpBlock3D",
+            "CogVideoXUpBlock3D",
+        ),
+        block_out_channels: Tuple[int, ...] = (128, 256, 256, 512),
+        layers_per_block: int = 3,
+        act_fn: str = "silu",
+        norm_eps: float = 1e-6,
+        norm_num_groups: int = 32,
+        dropout: float = 0.0,
+        pad_mode: str = "first",
+        temporal_compression_ratio: float = 4,
+    ):
+        super().__init__()
+
+        reversed_block_out_channels = list(reversed(block_out_channels))
+
+        self.conv_in = CogVideoXCausalConv3d(
+            in_channels, reversed_block_out_channels[0], kernel_size=3, pad_mode=pad_mode
+        )
+
+        # mid block
+        self.mid_block = CogVideoXMidBlock3D(
+            in_channels=reversed_block_out_channels[0],
+            temb_channels=0,
+            num_layers=2,
+            resnet_eps=norm_eps,
+            resnet_act_fn=act_fn,
+            resnet_groups=norm_num_groups,
+            spatial_norm_dim=in_channels,
+            pad_mode=pad_mode,
+        )
+
+        # up blocks
+        self.up_blocks = nn.ModuleList([])
+
+        output_channel = reversed_block_out_channels[0]
+        temporal_compress_level = int(np.log2(temporal_compression_ratio))
+
+        for i, up_block_type in enumerate(up_block_types):
+            prev_output_channel = output_channel
+            output_channel = reversed_block_out_channels[i]
+            is_final_block = i == len(block_out_channels) - 1
+            compress_time = i < temporal_compress_level
+
+            if up_block_type == "CogVideoXUpBlock3D":
+                up_block = CogVideoXUpBlock3D(
+                    in_channels=prev_output_channel,
+                    out_channels=output_channel,
+                    temb_channels=0,
+                    dropout=dropout,
+                    num_layers=layers_per_block + 1,
+                    resnet_eps=norm_eps,
+                    resnet_act_fn=act_fn,
+                    resnet_groups=norm_num_groups,
+                    spatial_norm_dim=in_channels,
+                    add_upsample=not is_final_block,
+                    compress_time=compress_time,
+                    pad_mode=pad_mode,
+                )
+                prev_output_channel = output_channel
+            else:
+                raise ValueError("Invalid `up_block_type` encountered. Must be `CogVideoXUpBlock3D`")
+
+            self.up_blocks.append(up_block)
+
+        self.norm_out = CogVideoXSpatialNorm3D(reversed_block_out_channels[-1], in_channels, groups=norm_num_groups)
+        self.conv_act = nn.SiLU()
+        self.conv_out = CogVideoXCausalConv3d(
+            reversed_block_out_channels[-1], out_channels, kernel_size=3, pad_mode=pad_mode
+        )
+
+        self.gradient_checkpointing = False
+
+    def forward(
+        self,
+        sample: torch.Tensor,
+        temb: Optional[torch.Tensor] = None,
+        conv_cache: Optional[Dict[str, torch.Tensor]] = None,
+    ) -> torch.Tensor:
+        r"""The forward method of the `CogVideoXDecoder3D` class."""
+
+        new_conv_cache = {}
+        conv_cache = conv_cache or {}
+
+        hidden_states, new_conv_cache["conv_in"] = self.conv_in(sample, conv_cache=conv_cache.get("conv_in"))
+
+        if torch.is_grad_enabled() and self.gradient_checkpointing:
+
+            def create_custom_forward(module):
+                def custom_forward(*inputs):
+                    return module(*inputs)
+
+                return custom_forward
+
+            # 1. Mid
+            hidden_states, new_conv_cache["mid_block"] = torch.utils.checkpoint.checkpoint(
+                create_custom_forward(self.mid_block),
+                hidden_states,
+                temb,
+                sample,
+                conv_cache.get("mid_block"),
+            )
+
+            # 2. Up
+            for i, up_block in enumerate(self.up_blocks):
+                conv_cache_key = f"up_block_{i}"
+                hidden_states, new_conv_cache[conv_cache_key] = torch.utils.checkpoint.checkpoint(
+                    create_custom_forward(up_block),
+                    hidden_states,
+                    temb,
+                    sample,
+                    conv_cache.get(conv_cache_key),
+                )
+        else:
+            # 1. Mid
+            hidden_states, new_conv_cache["mid_block"] = self.mid_block(
+                hidden_states, temb, sample, conv_cache=conv_cache.get("mid_block")
+            )
+
+            # 2. Up
+            for i, up_block in enumerate(self.up_blocks):
+                conv_cache_key = f"up_block_{i}"
+                hidden_states, new_conv_cache[conv_cache_key] = up_block(
+                    hidden_states, temb, sample, conv_cache=conv_cache.get(conv_cache_key)
+                )
+
+        # 3. Post-process
+        hidden_states, new_conv_cache["norm_out"] = self.norm_out(
+            hidden_states, sample, conv_cache=conv_cache.get("norm_out")
+        )
+        hidden_states = self.conv_act(hidden_states)
+        hidden_states, new_conv_cache["conv_out"] = self.conv_out(hidden_states, conv_cache=conv_cache.get("conv_out"))
+
+        return hidden_states, new_conv_cache
+
+
+class AutoencoderKLCogVideoX(ModelMixin, ConfigMixin, FromOriginalModelMixin):
+    r"""
+    A VAE model with KL loss for encoding images into latents and decoding latent representations into images. Used in
+    [CogVideoX](https://github.com/THUDM/CogVideo).
+
+    This model inherits from [`ModelMixin`]. Check the superclass documentation for it's generic methods implemented
+    for all models (such as downloading or saving).
+
+    Parameters:
+        in_channels (int, *optional*, defaults to 3): Number of channels in the input image.
+        out_channels (int,  *optional*, defaults to 3): Number of channels in the output.
+        down_block_types (`Tuple[str]`, *optional*, defaults to `("DownEncoderBlock2D",)`):
+            Tuple of downsample block types.
+        up_block_types (`Tuple[str]`, *optional*, defaults to `("UpDecoderBlock2D",)`):
+            Tuple of upsample block types.
+        block_out_channels (`Tuple[int]`, *optional*, defaults to `(64,)`):
+            Tuple of block output channels.
+        act_fn (`str`, *optional*, defaults to `"silu"`): The activation function to use.
+        sample_size (`int`, *optional*, defaults to `32`): Sample input size.
+        scaling_factor (`float`, *optional*, defaults to `1.15258426`):
+            The component-wise standard deviation of the trained latent space computed using the first batch of the
+            training set. This is used to scale the latent space to have unit variance when training the diffusion
+            model. The latents are scaled with the formula `z = z * scaling_factor` before being passed to the
+            diffusion model. When decoding, the latents are scaled back to the original scale with the formula: `z = 1
+            / scaling_factor * z`. For more details, refer to sections 4.3.2 and D.1 of the [High-Resolution Image
+            Synthesis with Latent Diffusion Models](https://arxiv.org/abs/2112.10752) paper.
+        force_upcast (`bool`, *optional*, default to `True`):
+            If enabled it will force the VAE to run in float32 for high image resolution pipelines, such as SD-XL. VAE
+            can be fine-tuned / trained to a lower range without loosing too much precision in which case
+            `force_upcast` can be set to `False` - see: https://huggingface.co/madebyollin/sdxl-vae-fp16-fix
+    """
+
+    _supports_gradient_checkpointing = True
+    _no_split_modules = ["CogVideoXResnetBlock3D"]
+
+    @register_to_config
+    def __init__(
+        self,
+        in_channels: int = 3,
+        out_channels: int = 3,
+        down_block_types: Tuple[str] = (
+            "CogVideoXDownBlock3D",
+            "CogVideoXDownBlock3D",
+            "CogVideoXDownBlock3D",
+            "CogVideoXDownBlock3D",
+        ),
+        up_block_types: Tuple[str] = (
+            "CogVideoXUpBlock3D",
+            "CogVideoXUpBlock3D",
+            "CogVideoXUpBlock3D",
+            "CogVideoXUpBlock3D",
+        ),
+        block_out_channels: Tuple[int] = (128, 256, 256, 512),
+        latent_channels: int = 16,
+        layers_per_block: int = 3,
+        act_fn: str = "silu",
+        norm_eps: float = 1e-6,
+        norm_num_groups: int = 32,
+        temporal_compression_ratio: float = 4,
+        sample_height: int = 480,
+        sample_width: int = 720,
+        scaling_factor: float = 1.15258426,
+        shift_factor: Optional[float] = None,
+        latents_mean: Optional[Tuple[float]] = None,
+        latents_std: Optional[Tuple[float]] = None,
+        force_upcast: float = True,
+        use_quant_conv: bool = False,
+        use_post_quant_conv: bool = False,
+        invert_scale_latents: bool = False,
+    ):
+        super().__init__()
+
+        self.encoder = CogVideoXEncoder3D(
+            in_channels=in_channels,
+            out_channels=latent_channels,
+            down_block_types=down_block_types,
+            block_out_channels=block_out_channels,
+            layers_per_block=layers_per_block,
+            act_fn=act_fn,
+            norm_eps=norm_eps,
+            norm_num_groups=norm_num_groups,
+            temporal_compression_ratio=temporal_compression_ratio,
+        )
+        self.decoder = CogVideoXDecoder3D(
+            in_channels=latent_channels,
+            out_channels=out_channels,
+            up_block_types=up_block_types,
+            block_out_channels=block_out_channels,
+            layers_per_block=layers_per_block,
+            act_fn=act_fn,
+            norm_eps=norm_eps,
+            norm_num_groups=norm_num_groups,
+            temporal_compression_ratio=temporal_compression_ratio,
+        )
+        self.quant_conv = CogVideoXSafeConv3d(2 * out_channels, 2 * out_channels, 1) if use_quant_conv else None
+        self.post_quant_conv = CogVideoXSafeConv3d(out_channels, out_channels, 1) if use_post_quant_conv else None
+
+        self.use_slicing = False
+        self.use_tiling = False
+        self.auto_split_process = False
+
+        # Can be increased to decode more latent frames at once, but comes at a reasonable memory cost and it is not
+        # recommended because the temporal parts of the VAE, here, are tricky to understand.
+        # If you decode X latent frames together, the number of output frames is:
+        #     (X + (2 conv cache) + (2 time upscale_1) + (4 time upscale_2) - (2 causal conv downscale)) => X + 6 frames
+        #
+        # Example with num_latent_frames_batch_size = 2:
+        #     - 12 latent frames: (0, 1), (2, 3), (4, 5), (6, 7), (8, 9), (10, 11) are processed together
+        #         => (12 // 2 frame slices) * ((2 num_latent_frames_batch_size) + (2 conv cache) + (2 time upscale_1) + (4 time upscale_2) - (2 causal conv downscale))
+        #         => 6 * 8 = 48 frames
+        #     - 13 latent frames: (0, 1, 2) (special case), (3, 4), (5, 6), (7, 8), (9, 10), (11, 12) are processed together
+        #         => (1 frame slice) * ((3 num_latent_frames_batch_size) + (2 conv cache) + (2 time upscale_1) + (4 time upscale_2) - (2 causal conv downscale)) +
+        #            ((13 - 3) // 2) * ((2 num_latent_frames_batch_size) + (2 conv cache) + (2 time upscale_1) + (4 time upscale_2) - (2 causal conv downscale))
+        #         => 1 * 9 + 5 * 8 = 49 frames
+        # It has been implemented this way so as to not have "magic values" in the code base that would be hard to explain. Note that
+        # setting it to anything other than 2 would give poor results because the VAE hasn't been trained to be adaptive with different
+        # number of temporal frames.
+        self.num_latent_frames_batch_size = 2
+        self.num_sample_frames_batch_size = 8
+
+        # We make the minimum height and width of sample for tiling half that of the generally supported
+        self.tile_sample_min_height = sample_height // 2
+        self.tile_sample_min_width = sample_width // 2
+        self.tile_latent_min_height = int(
+            self.tile_sample_min_height / (2 ** (len(self.config.block_out_channels) - 1))
+        )
+        self.tile_latent_min_width = int(self.tile_sample_min_width / (2 ** (len(self.config.block_out_channels) - 1)))
+
+        # These are experimental overlap factors that were chosen based on experimentation and seem to work best for
+        # 720x480 (WxH) resolution. The above resolution is the strongly recommended generation resolution in CogVideoX
+        # and so the tiling implementation has only been tested on those specific resolutions.
+        self.tile_overlap_factor_height = 1 / 6
+        self.tile_overlap_factor_width = 1 / 5
+
+    def _set_gradient_checkpointing(self, module, value=False):
+        if isinstance(module, (CogVideoXEncoder3D, CogVideoXDecoder3D)):
+            module.gradient_checkpointing = value
+
+    def enable_tiling(
+        self,
+        tile_sample_min_height: Optional[int] = None,
+        tile_sample_min_width: Optional[int] = None,
+        tile_overlap_factor_height: Optional[float] = None,
+        tile_overlap_factor_width: Optional[float] = None,
+    ) -> None:
+        r"""
+        Enable tiled VAE decoding. When this option is enabled, the VAE will split the input tensor into tiles to
+        compute decoding and encoding in several steps. This is useful for saving a large amount of memory and to allow
+        processing larger images.
+
+        Args:
+            tile_sample_min_height (`int`, *optional*):
+                The minimum height required for a sample to be separated into tiles across the height dimension.
+            tile_sample_min_width (`int`, *optional*):
+                The minimum width required for a sample to be separated into tiles across the width dimension.
+            tile_overlap_factor_height (`int`, *optional*):
+                The minimum amount of overlap between two consecutive vertical tiles. This is to ensure that there are
+                no tiling artifacts produced across the height dimension. Must be between 0 and 1. Setting a higher
+                value might cause more tiles to be processed leading to slow down of the decoding process.
+            tile_overlap_factor_width (`int`, *optional*):
+                The minimum amount of overlap between two consecutive horizontal tiles. This is to ensure that there
+                are no tiling artifacts produced across the width dimension. Must be between 0 and 1. Setting a higher
+                value might cause more tiles to be processed leading to slow down of the decoding process.
+        """
+        self.use_tiling = True
+        self.tile_sample_min_height = tile_sample_min_height or self.tile_sample_min_height
+        self.tile_sample_min_width = tile_sample_min_width or self.tile_sample_min_width
+        self.tile_latent_min_height = int(
+            self.tile_sample_min_height / (2 ** (len(self.config.block_out_channels) - 1))
+        )
+        self.tile_latent_min_width = int(self.tile_sample_min_width / (2 ** (len(self.config.block_out_channels) - 1)))
+        self.tile_overlap_factor_height = tile_overlap_factor_height or self.tile_overlap_factor_height
+        self.tile_overlap_factor_width = tile_overlap_factor_width or self.tile_overlap_factor_width
+
+    def disable_tiling(self) -> None:
+        r"""
+        Disable tiled VAE decoding. If `enable_tiling` was previously enabled, this method will go back to computing
+        decoding in one step.
+        """
+        self.use_tiling = False
+
+    def enable_slicing(self) -> None:
+        r"""
+        Enable sliced VAE decoding. When this option is enabled, the VAE will split the input tensor in slices to
+        compute decoding in several steps. This is useful to save some memory and allow larger batch sizes.
+        """
+        self.use_slicing = True
+
+    def disable_slicing(self) -> None:
+        r"""
+        Disable sliced VAE decoding. If `enable_slicing` was previously enabled, this method will go back to computing
+        decoding in one step.
+        """
+        self.use_slicing = False
+            
+    def _set_first_frame(self):
+        for name, module in self.named_modules():
+            if isinstance(module, CogVideoXUpsample3D):
+                module.auto_split_process = False
+                module.first_frame_flag = True
+
+    def _set_rest_frame(self):
+        for name, module in self.named_modules():
+            if isinstance(module, CogVideoXUpsample3D):
+                module.auto_split_process = False
+                module.first_frame_flag = False
+
+    def enable_auto_split_process(self) -> None:
+        self.auto_split_process = True
+        for name, module in self.named_modules():
+            if isinstance(module, CogVideoXUpsample3D):
+                module.auto_split_process = True
+
+    def disable_auto_split_process(self) -> None:
+        self.auto_split_process = False
+
+    def _encode(self, x: torch.Tensor) -> torch.Tensor:
+        batch_size, num_channels, num_frames, height, width = x.shape
+
+        if self.use_tiling and (width > self.tile_sample_min_width or height > self.tile_sample_min_height):
+            return self.tiled_encode(x)
+
+        frame_batch_size = self.num_sample_frames_batch_size
+        # Note: We expect the number of frames to be either `1` or `frame_batch_size * k` or `frame_batch_size * k + 1` for some k.
+        # As the extra single frame is handled inside the loop, it is not required to round up here.
+        num_batches = max(num_frames // frame_batch_size, 1)
+        conv_cache = None
+        enc = []
+
+        for i in range(num_batches):
+            remaining_frames = num_frames % frame_batch_size
+            start_frame = frame_batch_size * i + (0 if i == 0 else remaining_frames)
+            end_frame = frame_batch_size * (i + 1) + remaining_frames
+            x_intermediate = x[:, :, start_frame:end_frame]
+            x_intermediate, conv_cache = self.encoder(x_intermediate, conv_cache=conv_cache)
+            if self.quant_conv is not None:
+                x_intermediate = self.quant_conv(x_intermediate)
+            enc.append(x_intermediate)
+
+        enc = torch.cat(enc, dim=2)
+        return enc
+
+    @apply_forward_hook
+    def encode(
+        self, x: torch.Tensor, return_dict: bool = True
+    ) -> Union[AutoencoderKLOutput, Tuple[DiagonalGaussianDistribution]]:
+        """
+        Encode a batch of images into latents.
+
+        Args:
+            x (`torch.Tensor`): Input batch of images.
+            return_dict (`bool`, *optional*, defaults to `True`):
+                Whether to return a [`~models.autoencoder_kl.AutoencoderKLOutput`] instead of a plain tuple.
+
+        Returns:
+                The latent representations of the encoded videos. If `return_dict` is True, a
+                [`~models.autoencoder_kl.AutoencoderKLOutput`] is returned, otherwise a plain `tuple` is returned.
+        """
+        if self.use_slicing and x.shape[0] > 1:
+            encoded_slices = [self._encode(x_slice) for x_slice in x.split(1)]
+            h = torch.cat(encoded_slices)
+        else:
+            h = self._encode(x)
+
+        posterior = DiagonalGaussianDistribution(h)
+
+        if not return_dict:
+            return (posterior,)
+        return AutoencoderKLOutput(latent_dist=posterior)
+
+    def _decode(self, z: torch.Tensor, return_dict: bool = True) -> Union[DecoderOutput, torch.Tensor]:
+        batch_size, num_channels, num_frames, height, width = z.shape
+
+        if self.use_tiling and (width > self.tile_latent_min_width or height > self.tile_latent_min_height):
+            return self.tiled_decode(z, return_dict=return_dict)
+
+        if self.auto_split_process:
+            frame_batch_size = self.num_latent_frames_batch_size
+            num_batches = max(num_frames // frame_batch_size, 1)
+            conv_cache = None
+            dec = []
+
+            for i in range(num_batches):
+                remaining_frames = num_frames % frame_batch_size
+                start_frame = frame_batch_size * i + (0 if i == 0 else remaining_frames)
+                end_frame = frame_batch_size * (i + 1) + remaining_frames
+                z_intermediate = z[:, :, start_frame:end_frame]
+                if self.post_quant_conv is not None:
+                    z_intermediate = self.post_quant_conv(z_intermediate)
+                z_intermediate, conv_cache = self.decoder(z_intermediate, conv_cache=conv_cache)
+                dec.append(z_intermediate)
+        else:
+            conv_cache = None
+            start_frame = 0
+            end_frame = 1
+            dec = []
+
+            self._set_first_frame()
+            z_intermediate = z[:, :, start_frame:end_frame]
+            if self.post_quant_conv is not None:
+                z_intermediate = self.post_quant_conv(z_intermediate)
+            z_intermediate, conv_cache = self.decoder(z_intermediate, conv_cache=conv_cache)
+            dec.append(z_intermediate)
+
+            self._set_rest_frame()
+            start_frame = end_frame
+            end_frame += self.num_latent_frames_batch_size
+
+            while start_frame < num_frames:
+                z_intermediate = z[:, :, start_frame:end_frame]
+                if self.post_quant_conv is not None:
+                    z_intermediate = self.post_quant_conv(z_intermediate)
+                z_intermediate, conv_cache = self.decoder(z_intermediate, conv_cache=conv_cache)
+                dec.append(z_intermediate)
+                start_frame = end_frame
+                end_frame += self.num_latent_frames_batch_size
+
+        dec = torch.cat(dec, dim=2)
+
+        if not return_dict:
+            return (dec,)
+
+        return DecoderOutput(sample=dec)
+
+    @apply_forward_hook
+    def decode(self, z: torch.Tensor, return_dict: bool = True) -> Union[DecoderOutput, torch.Tensor]:
+        """
+        Decode a batch of images.
+
+        Args:
+            z (`torch.Tensor`): Input batch of latent vectors.
+            return_dict (`bool`, *optional*, defaults to `True`):
+                Whether to return a [`~models.vae.DecoderOutput`] instead of a plain tuple.
+
+        Returns:
+            [`~models.vae.DecoderOutput`] or `tuple`:
+                If return_dict is True, a [`~models.vae.DecoderOutput`] is returned, otherwise a plain `tuple` is
+                returned.
+        """
+        if self.use_slicing and z.shape[0] > 1:
+            decoded_slices = [self._decode(z_slice).sample for z_slice in z.split(1)]
+            decoded = torch.cat(decoded_slices)
+        else:
+            decoded = self._decode(z).sample
+
+        if not return_dict:
+            return (decoded,)
+        return DecoderOutput(sample=decoded)
+
+    def blend_v(self, a: torch.Tensor, b: torch.Tensor, blend_extent: int) -> torch.Tensor:
+        blend_extent = min(a.shape[3], b.shape[3], blend_extent)
+        for y in range(blend_extent):
+            b[:, :, :, y, :] = a[:, :, :, -blend_extent + y, :] * (1 - y / blend_extent) + b[:, :, :, y, :] * (
+                y / blend_extent
+            )
+        return b
+
+    def blend_h(self, a: torch.Tensor, b: torch.Tensor, blend_extent: int) -> torch.Tensor:
+        blend_extent = min(a.shape[4], b.shape[4], blend_extent)
+        for x in range(blend_extent):
+            b[:, :, :, :, x] = a[:, :, :, :, -blend_extent + x] * (1 - x / blend_extent) + b[:, :, :, :, x] * (
+                x / blend_extent
+            )
+        return b
+
+    def tiled_encode(self, x: torch.Tensor) -> torch.Tensor:
+        r"""Encode a batch of images using a tiled encoder.
+
+        When this option is enabled, the VAE will split the input tensor into tiles to compute encoding in several
+        steps. This is useful to keep memory use constant regardless of image size. The end result of tiled encoding is
+        different from non-tiled encoding because each tile uses a different encoder. To avoid tiling artifacts, the
+        tiles overlap and are blended together to form a smooth output. You may still see tile-sized changes in the
+        output, but they should be much less noticeable.
+
+        Args:
+            x (`torch.Tensor`): Input batch of videos.
+
+        Returns:
+            `torch.Tensor`:
+                The latent representation of the encoded videos.
+        """
+        # For a rough memory estimate, take a look at the `tiled_decode` method.
+        batch_size, num_channels, num_frames, height, width = x.shape
+
+        overlap_height = int(self.tile_sample_min_height * (1 - self.tile_overlap_factor_height))
+        overlap_width = int(self.tile_sample_min_width * (1 - self.tile_overlap_factor_width))
+        blend_extent_height = int(self.tile_latent_min_height * self.tile_overlap_factor_height)
+        blend_extent_width = int(self.tile_latent_min_width * self.tile_overlap_factor_width)
+        row_limit_height = self.tile_latent_min_height - blend_extent_height
+        row_limit_width = self.tile_latent_min_width - blend_extent_width
+        frame_batch_size = self.num_sample_frames_batch_size
+
+        # Split x into overlapping tiles and encode them separately.
+        # The tiles have an overlap to avoid seams between tiles.
+        rows = []
+        for i in range(0, height, overlap_height):
+            row = []
+            for j in range(0, width, overlap_width):
+                # Note: We expect the number of frames to be either `1` or `frame_batch_size * k` or `frame_batch_size * k + 1` for some k.
+                # As the extra single frame is handled inside the loop, it is not required to round up here.
+                num_batches = max(num_frames // frame_batch_size, 1)
+                conv_cache = None
+                time = []
+
+                for k in range(num_batches):
+                    remaining_frames = num_frames % frame_batch_size
+                    start_frame = frame_batch_size * k + (0 if k == 0 else remaining_frames)
+                    end_frame = frame_batch_size * (k + 1) + remaining_frames
+                    tile = x[
+                        :,
+                        :,
+                        start_frame:end_frame,
+                        i : i + self.tile_sample_min_height,
+                        j : j + self.tile_sample_min_width,
+                    ]
+                    tile, conv_cache = self.encoder(tile, conv_cache=conv_cache)
+                    if self.quant_conv is not None:
+                        tile = self.quant_conv(tile)
+                    time.append(tile)
+
+                row.append(torch.cat(time, dim=2))
+            rows.append(row)
+
+        result_rows = []
+        for i, row in enumerate(rows):
+            result_row = []
+            for j, tile in enumerate(row):
+                # blend the above tile and the left tile
+                # to the current tile and add the current tile to the result row
+                if i > 0:
+                    tile = self.blend_v(rows[i - 1][j], tile, blend_extent_height)
+                if j > 0:
+                    tile = self.blend_h(row[j - 1], tile, blend_extent_width)
+                result_row.append(tile[:, :, :, :row_limit_height, :row_limit_width])
+            result_rows.append(torch.cat(result_row, dim=4))
+
+        enc = torch.cat(result_rows, dim=3)
+        return enc
+
+    def tiled_decode(self, z: torch.Tensor, return_dict: bool = True) -> Union[DecoderOutput, torch.Tensor]:
+        r"""
+        Decode a batch of images using a tiled decoder.
+
+        Args:
+            z (`torch.Tensor`): Input batch of latent vectors.
+            return_dict (`bool`, *optional*, defaults to `True`):
+                Whether or not to return a [`~models.vae.DecoderOutput`] instead of a plain tuple.
+
+        Returns:
+            [`~models.vae.DecoderOutput`] or `tuple`:
+                If return_dict is True, a [`~models.vae.DecoderOutput`] is returned, otherwise a plain `tuple` is
+                returned.
+        """
+        # Rough memory assessment:
+        #   - In CogVideoX-2B, there are a total of 24 CausalConv3d layers.
+        #   - The biggest intermediate dimensions are: [1, 128, 9, 480, 720].
+        #   - Assume fp16 (2 bytes per value).
+        # Memory required: 1 * 128 * 9 * 480 * 720 * 24 * 2 / 1024**3 = 17.8 GB
+        #
+        # Memory assessment when using tiling:
+        #   - Assume everything as above but now HxW is 240x360 by tiling in half
+        # Memory required: 1 * 128 * 9 * 240 * 360 * 24 * 2 / 1024**3 = 4.5 GB
+
+        batch_size, num_channels, num_frames, height, width = z.shape
+
+        overlap_height = int(self.tile_latent_min_height * (1 - self.tile_overlap_factor_height))
+        overlap_width = int(self.tile_latent_min_width * (1 - self.tile_overlap_factor_width))
+        blend_extent_height = int(self.tile_sample_min_height * self.tile_overlap_factor_height)
+        blend_extent_width = int(self.tile_sample_min_width * self.tile_overlap_factor_width)
+        row_limit_height = self.tile_sample_min_height - blend_extent_height
+        row_limit_width = self.tile_sample_min_width - blend_extent_width
+        frame_batch_size = self.num_latent_frames_batch_size
+
+        # Split z into overlapping tiles and decode them separately.
+        # The tiles have an overlap to avoid seams between tiles.
+        rows = []
+        for i in range(0, height, overlap_height):
+            row = []
+            for j in range(0, width, overlap_width):
+                if self.auto_split_process:
+                    num_batches = max(num_frames // frame_batch_size, 1)
+                    conv_cache = None
+                    time = []
+
+                    for k in range(num_batches):
+                        remaining_frames = num_frames % frame_batch_size
+                        start_frame = frame_batch_size * k + (0 if k == 0 else remaining_frames)
+                        end_frame = frame_batch_size * (k + 1) + remaining_frames
+                        tile = z[
+                            :,
+                            :,
+                            start_frame:end_frame,
+                            i : i + self.tile_latent_min_height,
+                            j : j + self.tile_latent_min_width,
+                        ]
+                        if self.post_quant_conv is not None:
+                            tile = self.post_quant_conv(tile)
+                        tile, conv_cache = self.decoder(tile, conv_cache=conv_cache)
+                        time.append(tile)
+
+                    row.append(torch.cat(time, dim=2))
+                else:
+                    conv_cache = None
+                    start_frame = 0
+                    end_frame = 1
+                    dec = []
+
+                    tile = z[
+                        :,
+                        :,
+                        start_frame:end_frame,
+                        i : i + self.tile_latent_min_height,
+                        j : j + self.tile_latent_min_width,
+                    ]
+
+                    self._set_first_frame()
+                    if self.post_quant_conv is not None:
+                        tile = self.post_quant_conv(tile)
+                    tile, conv_cache = self.decoder(tile, conv_cache=conv_cache)
+                    dec.append(tile)
+                    
+                    self._set_rest_frame()
+                    start_frame = end_frame
+                    end_frame += self.num_latent_frames_batch_size
+
+                    while start_frame < num_frames:
+                        tile = z[
+                            :,
+                            :,
+                            start_frame:end_frame,
+                            i : i + self.tile_latent_min_height,
+                            j : j + self.tile_latent_min_width,
+                        ]
+                        if self.post_quant_conv is not None:
+                            tile = self.post_quant_conv(tile)
+                        tile, conv_cache = self.decoder(tile, conv_cache=conv_cache)
+                        dec.append(tile)
+                        start_frame = end_frame
+                        end_frame += self.num_latent_frames_batch_size
+
+                    row.append(torch.cat(dec, dim=2))
+            rows.append(row)
+
+        result_rows = []
+        for i, row in enumerate(rows):
+            result_row = []
+            for j, tile in enumerate(row):
+                # blend the above tile and the left tile
+                # to the current tile and add the current tile to the result row
+                if i > 0:
+                    tile = self.blend_v(rows[i - 1][j], tile, blend_extent_height)
+                if j > 0:
+                    tile = self.blend_h(row[j - 1], tile, blend_extent_width)
+                result_row.append(tile[:, :, :, :row_limit_height, :row_limit_width])
+            result_rows.append(torch.cat(result_row, dim=4))
+
+        dec = torch.cat(result_rows, dim=3)
+
+        if not return_dict:
+            return (dec,)
+
+        return DecoderOutput(sample=dec)
+
+    def forward(
+        self,
+        sample: torch.Tensor,
+        sample_posterior: bool = False,
+        return_dict: bool = True,
+        generator: Optional[torch.Generator] = None,
+    ) -> Union[torch.Tensor, torch.Tensor]:
+        x = sample
+        posterior = self.encode(x).latent_dist
+        if sample_posterior:
+            z = posterior.sample(generator=generator)
+        else:
+            z = posterior.mode()
+        dec = self.decode(z)
+        if not return_dict:
+            return (dec,)
+        return dec
+            
+    @classmethod
+    def from_pretrained(cls, pretrained_model_path, subfolder=None, **vae_additional_kwargs):
+        if subfolder is not None:
+            pretrained_model_path = os.path.join(pretrained_model_path, subfolder)
+
+        config_file = os.path.join(pretrained_model_path, 'config.json')
+        if not os.path.isfile(config_file):
+            raise RuntimeError(f"{config_file} does not exist")
+        with open(config_file, "r") as f:
+            config = json.load(f)
+
+        model = cls.from_config(config, **vae_additional_kwargs)
+        from diffusers.utils import WEIGHTS_NAME
+        model_file = os.path.join(pretrained_model_path, WEIGHTS_NAME)
+        model_file_safetensors = model_file.replace(".bin", ".safetensors")
+        if os.path.exists(model_file_safetensors):
+            from safetensors.torch import load_file, safe_open
+            state_dict = load_file(model_file_safetensors)
+        else:
+            if not os.path.isfile(model_file):
+                raise RuntimeError(f"{model_file} does not exist")
+            state_dict = torch.load(model_file, map_location="cpu")
+        m, u = model.load_state_dict(state_dict, strict=False)
+        print(f"### missing keys: {len(m)}; \n### unexpected keys: {len(u)};")
+        print(m, u)
+        return model