HunyuanImage-3.0 / autoencoder_kl_3d.py
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# Licensed under the TENCENT HUNYUAN COMMUNITY LICENSE AGREEMENT (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# https://github.com/Tencent-Hunyuan/HunyuanImage-3.0/blob/main/LICENSE
#
# 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 dataclasses import dataclass
from typing import Tuple, Optional
import math
import random
import numpy as np
from einops import rearrange
import torch
from torch import Tensor, nn
import torch.nn.functional as F
from diffusers.configuration_utils import ConfigMixin, register_to_config
from diffusers.models.modeling_outputs import AutoencoderKLOutput
from diffusers.models.modeling_utils import ModelMixin
from diffusers.utils.torch_utils import randn_tensor
from diffusers.utils import BaseOutput
class DiagonalGaussianDistribution(object):
def __init__(self, parameters: torch.Tensor, deterministic: bool = False):
if parameters.ndim == 3:
dim = 2 # (B, L, C)
elif parameters.ndim == 5 or parameters.ndim == 4:
dim = 1 # (B, C, T, H ,W) / (B, C, H, W)
else:
raise NotImplementedError
self.parameters = parameters
self.mean, self.logvar = torch.chunk(parameters, 2, dim=dim)
self.logvar = torch.clamp(self.logvar, -30.0, 20.0)
self.deterministic = deterministic
self.std = torch.exp(0.5 * self.logvar)
self.var = torch.exp(self.logvar)
if self.deterministic:
self.var = self.std = torch.zeros_like(
self.mean, device=self.parameters.device, dtype=self.parameters.dtype
)
def sample(self, generator: Optional[torch.Generator] = None) -> torch.FloatTensor:
# make sure sample is on the same device as the parameters and has same dtype
sample = randn_tensor(
self.mean.shape,
generator=generator,
device=self.parameters.device,
dtype=self.parameters.dtype,
)
x = self.mean + self.std * sample
return x
def kl(self, other: "DiagonalGaussianDistribution" = None) -> torch.Tensor:
if self.deterministic:
return torch.Tensor([0.0])
else:
reduce_dim = list(range(1, self.mean.ndim))
if other is None:
return 0.5 * torch.sum(
torch.pow(self.mean, 2) + self.var - 1.0 - self.logvar,
dim=reduce_dim,
)
else:
return 0.5 * torch.sum(
torch.pow(self.mean - other.mean, 2) / other.var +
self.var / other.var -
1.0 -
self.logvar +
other.logvar,
dim=reduce_dim,
)
def nll(self, sample: torch.Tensor, dims: Tuple[int, ...] = [1, 2, 3]) -> torch.Tensor:
if self.deterministic:
return torch.Tensor([0.0])
logtwopi = np.log(2.0 * np.pi)
return 0.5 * torch.sum(
logtwopi + self.logvar + torch.pow(sample - self.mean, 2) / self.var,
dim=dims,
)
def mode(self) -> torch.Tensor:
return self.mean
@dataclass
class DecoderOutput(BaseOutput):
sample: torch.FloatTensor
posterior: Optional[DiagonalGaussianDistribution] = None
def swish(x: Tensor) -> Tensor:
return x * torch.sigmoid(x)
def forward_with_checkpointing(module, *inputs, use_checkpointing=False):
def create_custom_forward(module):
def custom_forward(*inputs):
return module(*inputs)
return custom_forward
if use_checkpointing:
return torch.utils.checkpoint.checkpoint(create_custom_forward(module), *inputs, use_reentrant=False)
else:
return module(*inputs)
class Conv3d(nn.Conv3d):
"""
Perform Conv3d on patches with numerical differences from nn.Conv3d within 1e-5.
Only symmetric padding is supported.
"""
def forward(self, input):
B, C, T, H, W = input.shape
memory_count = (C * T * H * W) * 2 / 1024**3
if memory_count > 2:
n_split = math.ceil(memory_count / 2)
assert n_split >= 2
chunks = torch.chunk(input, chunks=n_split, dim=-3)
padded_chunks = []
for i in range(len(chunks)):
if self.padding[0] > 0:
padded_chunk = F.pad(
chunks[i],
(0, 0, 0, 0, self.padding[0], self.padding[0]),
mode="constant" if self.padding_mode == "zeros" else self.padding_mode,
value=0,
)
if i > 0:
padded_chunk[:, :, :self.padding[0]] = chunks[i - 1][:, :, -self.padding[0]:]
if i < len(chunks) - 1:
padded_chunk[:, :, -self.padding[0]:] = chunks[i + 1][:, :, :self.padding[0]]
else:
padded_chunk = chunks[i]
padded_chunks.append(padded_chunk)
padding_bak = self.padding
self.padding = (0, self.padding[1], self.padding[2])
outputs = []
for i in range(len(padded_chunks)):
outputs.append(super().forward(padded_chunks[i]))
self.padding = padding_bak
return torch.cat(outputs, dim=-3)
else:
return super().forward(input)
class AttnBlock(nn.Module):
""" Attention with torch sdpa implementation. """
def __init__(self, in_channels: int):
super().__init__()
self.in_channels = in_channels
self.norm = nn.GroupNorm(num_groups=32, num_channels=in_channels, eps=1e-6, affine=True)
self.q = Conv3d(in_channels, in_channels, kernel_size=1)
self.k = Conv3d(in_channels, in_channels, kernel_size=1)
self.v = Conv3d(in_channels, in_channels, kernel_size=1)
self.proj_out = Conv3d(in_channels, in_channels, kernel_size=1)
def attention(self, h_: Tensor) -> Tensor:
h_ = self.norm(h_)
q = self.q(h_)
k = self.k(h_)
v = self.v(h_)
b, c, f, h, w = q.shape
q = rearrange(q, "b c f h w -> b 1 (f h w) c").contiguous()
k = rearrange(k, "b c f h w -> b 1 (f h w) c").contiguous()
v = rearrange(v, "b c f h w -> b 1 (f h w) c").contiguous()
h_ = nn.functional.scaled_dot_product_attention(q, k, v)
return rearrange(h_, "b 1 (f h w) c -> b c f h w", f=f, h=h, w=w, c=c, b=b)
def forward(self, x: Tensor) -> Tensor:
return x + self.proj_out(self.attention(x))
class ResnetBlock(nn.Module):
def __init__(self, in_channels: int, out_channels: int):
super().__init__()
self.in_channels = in_channels
out_channels = in_channels if out_channels is None else out_channels
self.out_channels = out_channels
self.norm1 = nn.GroupNorm(num_groups=32, num_channels=in_channels, eps=1e-6, affine=True)
self.conv1 = Conv3d(in_channels, out_channels, kernel_size=3, stride=1, padding=1)
self.norm2 = nn.GroupNorm(num_groups=32, num_channels=out_channels, eps=1e-6, affine=True)
self.conv2 = Conv3d(out_channels, out_channels, kernel_size=3, stride=1, padding=1)
if self.in_channels != self.out_channels:
self.nin_shortcut = Conv3d(in_channels, out_channels, kernel_size=1, stride=1, padding=0)
def forward(self, x):
h = x
h = self.norm1(h)
h = swish(h)
h = self.conv1(h)
h = self.norm2(h)
h = swish(h)
h = self.conv2(h)
if self.in_channels != self.out_channels:
x = self.nin_shortcut(x)
return x + h
class Downsample(nn.Module):
def __init__(self, in_channels: int, add_temporal_downsample: bool = True):
super().__init__()
self.add_temporal_downsample = add_temporal_downsample
stride = (2, 2, 2) if add_temporal_downsample else (1, 2, 2) # THW
# no asymmetric padding in torch conv, must do it ourselves
self.conv = Conv3d(in_channels, in_channels, kernel_size=3, stride=stride, padding=0)
def forward(self, x: Tensor):
spatial_pad = (0, 1, 0, 1, 0, 0) # WHT
x = nn.functional.pad(x, spatial_pad, mode="constant", value=0)
temporal_pad = (0, 0, 0, 0, 0, 1) if self.add_temporal_downsample else (0, 0, 0, 0, 1, 1)
x = nn.functional.pad(x, temporal_pad, mode="replicate")
x = self.conv(x)
return x
class DownsampleDCAE(nn.Module):
def __init__(self, in_channels: int, out_channels: int, add_temporal_downsample: bool = True):
super().__init__()
factor = 2 * 2 * 2 if add_temporal_downsample else 1 * 2 * 2
assert out_channels % factor == 0
self.conv = Conv3d(in_channels, out_channels // factor, kernel_size=3, stride=1, padding=1)
self.add_temporal_downsample = add_temporal_downsample
self.group_size = factor * in_channels // out_channels
def forward(self, x: Tensor):
r1 = 2 if self.add_temporal_downsample else 1
h = self.conv(x)
h = rearrange(h, "b c (f r1) (h r2) (w r3) -> b (r1 r2 r3 c) f h w", r1=r1, r2=2, r3=2)
shortcut = rearrange(x, "b c (f r1) (h r2) (w r3) -> b (r1 r2 r3 c) f h w", r1=r1, r2=2, r3=2)
B, C, T, H, W = shortcut.shape
shortcut = shortcut.view(B, h.shape[1], self.group_size, T, H, W).mean(dim=2)
return h + shortcut
class Upsample(nn.Module):
def __init__(self, in_channels: int, add_temporal_upsample: bool = True):
super().__init__()
self.add_temporal_upsample = add_temporal_upsample
self.scale_factor = (2, 2, 2) if add_temporal_upsample else (1, 2, 2) # THW
self.conv = Conv3d(in_channels, in_channels, kernel_size=3, stride=1, padding=1)
def forward(self, x: Tensor):
x = nn.functional.interpolate(x, scale_factor=self.scale_factor, mode="nearest")
x = self.conv(x)
return x
class UpsampleDCAE(nn.Module):
def __init__(self, in_channels: int, out_channels: int, add_temporal_upsample: bool = True):
super().__init__()
factor = 2 * 2 * 2 if add_temporal_upsample else 1 * 2 * 2
self.conv = Conv3d(in_channels, out_channels * factor, kernel_size=3, stride=1, padding=1)
self.add_temporal_upsample = add_temporal_upsample
self.repeats = factor * out_channels // in_channels
def forward(self, x: Tensor):
r1 = 2 if self.add_temporal_upsample else 1
h = self.conv(x)
h = rearrange(h, "b (r1 r2 r3 c) f h w -> b c (f r1) (h r2) (w r3)", r1=r1, r2=2, r3=2)
shortcut = x.repeat_interleave(repeats=self.repeats, dim=1)
shortcut = rearrange(shortcut, "b (r1 r2 r3 c) f h w -> b c (f r1) (h r2) (w r3)", r1=r1, r2=2, r3=2)
return h + shortcut
class Encoder(nn.Module):
"""
The encoder network of AutoencoderKLConv3D.
"""
def __init__(
self,
in_channels: int,
z_channels: int,
block_out_channels: Tuple[int, ...],
num_res_blocks: int,
ffactor_spatial: int,
ffactor_temporal: int,
downsample_match_channel: bool = True,
):
super().__init__()
assert block_out_channels[-1] % (2 * z_channels) == 0
self.z_channels = z_channels
self.block_out_channels = block_out_channels
self.num_res_blocks = num_res_blocks
# downsampling
self.conv_in = Conv3d(in_channels, block_out_channels[0], kernel_size=3, stride=1, padding=1)
self.down = nn.ModuleList()
block_in = block_out_channels[0]
for i_level, ch in enumerate(block_out_channels):
block = nn.ModuleList()
block_out = ch
for _ in range(self.num_res_blocks):
block.append(ResnetBlock(in_channels=block_in, out_channels=block_out))
block_in = block_out
down = nn.Module()
down.block = block
add_spatial_downsample = bool(i_level < np.log2(ffactor_spatial))
add_temporal_downsample = (add_spatial_downsample and
bool(i_level >= np.log2(ffactor_spatial // ffactor_temporal)))
if add_spatial_downsample or add_temporal_downsample:
assert i_level < len(block_out_channels) - 1
block_out = block_out_channels[i_level + 1] if downsample_match_channel else block_in
down.downsample = DownsampleDCAE(block_in, block_out, add_temporal_downsample)
block_in = block_out
self.down.append(down)
# middle
self.mid = nn.Module()
self.mid.block_1 = ResnetBlock(in_channels=block_in, out_channels=block_in)
self.mid.attn_1 = AttnBlock(block_in)
self.mid.block_2 = ResnetBlock(in_channels=block_in, out_channels=block_in)
# end
self.norm_out = nn.GroupNorm(num_groups=32, num_channels=block_in, eps=1e-6, affine=True)
self.conv_out = Conv3d(block_in, 2 * z_channels, kernel_size=3, stride=1, padding=1)
self.gradient_checkpointing = False
def forward(self, x: Tensor) -> Tensor:
use_checkpointing = bool(self.training and self.gradient_checkpointing)
# downsampling
h = self.conv_in(x)
for i_level in range(len(self.block_out_channels)):
for i_block in range(self.num_res_blocks):
h = forward_with_checkpointing(
self.down[i_level].block[i_block], h, use_checkpointing=use_checkpointing)
if hasattr(self.down[i_level], "downsample"):
h = forward_with_checkpointing(self.down[i_level].downsample, h, use_checkpointing=use_checkpointing)
# middle
h = forward_with_checkpointing(self.mid.block_1, h, use_checkpointing=use_checkpointing)
h = forward_with_checkpointing(self.mid.attn_1, h, use_checkpointing=use_checkpointing)
h = forward_with_checkpointing(self.mid.block_2, h, use_checkpointing=use_checkpointing)
# end
group_size = self.block_out_channels[-1] // (2 * self.z_channels)
shortcut = rearrange(h, "b (c r) f h w -> b c r f h w", r=group_size).mean(dim=2)
h = self.norm_out(h)
h = swish(h)
h = self.conv_out(h)
h += shortcut
return h
class Decoder(nn.Module):
"""
The decoder network of AutoencoderKLConv3D.
"""
def __init__(
self,
z_channels: int,
out_channels: int,
block_out_channels: Tuple[int, ...],
num_res_blocks: int,
ffactor_spatial: int,
ffactor_temporal: int,
upsample_match_channel: bool = True,
):
super().__init__()
assert block_out_channels[0] % z_channels == 0
self.z_channels = z_channels
self.block_out_channels = block_out_channels
self.num_res_blocks = num_res_blocks
# z to block_in
block_in = block_out_channels[0]
self.conv_in = Conv3d(z_channels, block_in, kernel_size=3, stride=1, padding=1)
# middle
self.mid = nn.Module()
self.mid.block_1 = ResnetBlock(in_channels=block_in, out_channels=block_in)
self.mid.attn_1 = AttnBlock(block_in)
self.mid.block_2 = ResnetBlock(in_channels=block_in, out_channels=block_in)
# upsampling
self.up = nn.ModuleList()
for i_level, ch in enumerate(block_out_channels):
block = nn.ModuleList()
block_out = ch
for _ in range(self.num_res_blocks + 1):
block.append(ResnetBlock(in_channels=block_in, out_channels=block_out))
block_in = block_out
up = nn.Module()
up.block = block
add_spatial_upsample = bool(i_level < np.log2(ffactor_spatial))
add_temporal_upsample = bool(i_level < np.log2(ffactor_temporal))
if add_spatial_upsample or add_temporal_upsample:
assert i_level < len(block_out_channels) - 1
block_out = block_out_channels[i_level + 1] if upsample_match_channel else block_in
up.upsample = UpsampleDCAE(block_in, block_out, add_temporal_upsample)
block_in = block_out
self.up.append(up)
# end
self.norm_out = nn.GroupNorm(num_groups=32, num_channels=block_in, eps=1e-6, affine=True)
self.conv_out = Conv3d(block_in, out_channels, kernel_size=3, stride=1, padding=1)
self.gradient_checkpointing = False
def forward(self, z: Tensor) -> Tensor:
use_checkpointing = bool(self.training and self.gradient_checkpointing)
# z to block_in
repeats = self.block_out_channels[0] // (self.z_channels)
h = self.conv_in(z) + z.repeat_interleave(repeats=repeats, dim=1)
# middle
h = forward_with_checkpointing(self.mid.block_1, h, use_checkpointing=use_checkpointing)
h = forward_with_checkpointing(self.mid.attn_1, h, use_checkpointing=use_checkpointing)
h = forward_with_checkpointing(self.mid.block_2, h, use_checkpointing=use_checkpointing)
# upsampling
for i_level in range(len(self.block_out_channels)):
for i_block in range(self.num_res_blocks + 1):
h = forward_with_checkpointing(self.up[i_level].block[i_block], h, use_checkpointing=use_checkpointing)
if hasattr(self.up[i_level], "upsample"):
h = forward_with_checkpointing(self.up[i_level].upsample, h, use_checkpointing=use_checkpointing)
# end
h = self.norm_out(h)
h = swish(h)
h = self.conv_out(h)
return h
class AutoencoderKLConv3D(ModelMixin, ConfigMixin):
"""
Autoencoder model with KL-regularized latent space based on 3D convolutions.
"""
_supports_gradient_checkpointing = True
@register_to_config
def __init__(
self,
in_channels: int,
out_channels: int,
latent_channels: int,
block_out_channels: Tuple[int, ...],
layers_per_block: int,
ffactor_spatial: int,
ffactor_temporal: int,
sample_size: int,
sample_tsize: int,
scaling_factor: float = None,
shift_factor: Optional[float] = None,
downsample_match_channel: bool = True,
upsample_match_channel: bool = True,
only_encoder: bool = False, # only build encoder for saving memory
only_decoder: bool = False, # only build decoder for saving memory
):
super().__init__()
self.ffactor_spatial = ffactor_spatial
self.ffactor_temporal = ffactor_temporal
self.scaling_factor = scaling_factor
self.shift_factor = shift_factor
# build model
if not only_decoder:
self.encoder = Encoder(
in_channels=in_channels,
z_channels=latent_channels,
block_out_channels=block_out_channels,
num_res_blocks=layers_per_block,
ffactor_spatial=ffactor_spatial,
ffactor_temporal=ffactor_temporal,
downsample_match_channel=downsample_match_channel,
)
if not only_encoder:
self.decoder = Decoder(
z_channels=latent_channels,
out_channels=out_channels,
block_out_channels=list(reversed(block_out_channels)),
num_res_blocks=layers_per_block,
ffactor_spatial=ffactor_spatial,
ffactor_temporal=ffactor_temporal,
upsample_match_channel=upsample_match_channel,
)
# slicing and tiling related
self.use_slicing = False
self.slicing_bsz = 1
self.use_spatial_tiling = False
self.use_temporal_tiling = False
self.use_tiling_during_training = False
# only relevant if vae tiling is enabled
self.tile_sample_min_size = sample_size
self.tile_latent_min_size = sample_size // ffactor_spatial
self.tile_sample_min_tsize = sample_tsize
self.tile_latent_min_tsize = sample_tsize // ffactor_temporal
self.tile_overlap_factor = 0.25
# use torch.compile for faster encode speed
self.use_compile = False
def _set_gradient_checkpointing(self, module, value=False):
if isinstance(module, (Encoder, Decoder)):
module.gradient_checkpointing = value
def enable_tiling_during_training(self, use_tiling: bool = True):
self.use_tiling_during_training = use_tiling
def disable_tiling_during_training(self):
self.enable_tiling_during_training(False)
def enable_temporal_tiling(self, use_tiling: bool = True):
self.use_temporal_tiling = use_tiling
def disable_temporal_tiling(self):
self.enable_temporal_tiling(False)
def enable_spatial_tiling(self, use_tiling: bool = True):
self.use_spatial_tiling = use_tiling
def disable_spatial_tiling(self):
self.enable_spatial_tiling(False)
def enable_tiling(self, use_tiling: bool = True):
self.enable_spatial_tiling(use_tiling)
def disable_tiling(self):
self.disable_spatial_tiling()
def enable_slicing(self):
self.use_slicing = True
def disable_slicing(self):
self.use_slicing = False
def blend_h(self, a: torch.Tensor, b: torch.Tensor, blend_extent: int):
blend_extent = min(a.shape[-1], b.shape[-1], 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 blend_v(self, a: torch.Tensor, b: torch.Tensor, blend_extent: int):
blend_extent = min(a.shape[-2], b.shape[-2], 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_t(self, a: torch.Tensor, b: torch.Tensor, blend_extent: int):
blend_extent = min(a.shape[-3], b.shape[-3], 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 spatial_tiled_encode(self, x: torch.Tensor):
""" spatial tailing for frames """
B, C, T, H, W = x.shape
overlap_size = int(self.tile_sample_min_size * (1 - self.tile_overlap_factor)) # 256 * (1 - 0.25) = 192
blend_extent = int(self.tile_latent_min_size * self.tile_overlap_factor) # 8 * 0.25 = 2
row_limit = self.tile_latent_min_size - blend_extent # 8 - 2 = 6
rows = []
for i in range(0, H, overlap_size):
row = []
for j in range(0, W, overlap_size):
tile = x[:, :, :, i: i + self.tile_sample_min_size, j: j + self.tile_sample_min_size]
tile = self.encoder(tile)
row.append(tile)
rows.append(row)
result_rows = []
for i, row in enumerate(rows):
result_row = []
for j, tile in enumerate(row):
if i > 0:
tile = self.blend_v(rows[i - 1][j], tile, blend_extent)
if j > 0:
tile = self.blend_h(row[j - 1], tile, blend_extent)
result_row.append(tile[:, :, :, :row_limit, :row_limit])
result_rows.append(torch.cat(result_row, dim=-1))
moments = torch.cat(result_rows, dim=-2)
return moments
def temporal_tiled_encode(self, x: torch.Tensor):
""" temporal tailing for frames """
B, C, T, H, W = x.shape
overlap_size = int(self.tile_sample_min_tsize * (1 - self.tile_overlap_factor)) # 64 * (1 - 0.25) = 48
blend_extent = int(self.tile_latent_min_tsize * self.tile_overlap_factor) # 8 * 0.25 = 2
t_limit = self.tile_latent_min_tsize - blend_extent # 8 - 2 = 6
row = []
for i in range(0, T, overlap_size):
tile = x[:, :, i: i + self.tile_sample_min_tsize, :, :]
if self.use_spatial_tiling and (
tile.shape[-1] > self.tile_sample_min_size or tile.shape[-2] > self.tile_sample_min_size):
tile = self.spatial_tiled_encode(tile)
else:
tile = self.encoder(tile)
row.append(tile)
result_row = []
for i, tile in enumerate(row):
if i > 0:
tile = self.blend_t(row[i - 1], tile, blend_extent)
result_row.append(tile[:, :, :t_limit, :, :])
moments = torch.cat(result_row, dim=-3)
return moments
def spatial_tiled_decode(self, z: torch.Tensor):
""" spatial tailing for frames """
B, C, T, H, W = z.shape
overlap_size = int(self.tile_latent_min_size * (1 - self.tile_overlap_factor)) # 8 * (1 - 0.25) = 6
blend_extent = int(self.tile_sample_min_size * self.tile_overlap_factor) # 256 * 0.25 = 64
row_limit = self.tile_sample_min_size - blend_extent # 256 - 64 = 192
rows = []
for i in range(0, H, overlap_size):
row = []
for j in range(0, W, overlap_size):
tile = z[:, :, :, i: i + self.tile_latent_min_size, j: j + self.tile_latent_min_size]
decoded = self.decoder(tile)
row.append(decoded)
rows.append(row)
result_rows = []
for i, row in enumerate(rows):
result_row = []
for j, tile in enumerate(row):
if i > 0:
tile = self.blend_v(rows[i - 1][j], tile, blend_extent)
if j > 0:
tile = self.blend_h(row[j - 1], tile, blend_extent)
result_row.append(tile[:, :, :, :row_limit, :row_limit])
result_rows.append(torch.cat(result_row, dim=-1))
dec = torch.cat(result_rows, dim=-2)
return dec
def temporal_tiled_decode(self, z: torch.Tensor):
""" temporal tailing for frames """
B, C, T, H, W = z.shape
overlap_size = int(self.tile_latent_min_tsize * (1 - self.tile_overlap_factor)) # 8 * (1 - 0.25) = 6
blend_extent = int(self.tile_sample_min_tsize * self.tile_overlap_factor) # 64 * 0.25 = 16
t_limit = self.tile_sample_min_tsize - blend_extent # 64 - 16 = 48
assert 0 < overlap_size < self.tile_latent_min_tsize
row = []
for i in range(0, T, overlap_size):
tile = z[:, :, i: i + self.tile_latent_min_tsize, :, :]
if self.use_spatial_tiling and (
tile.shape[-1] > self.tile_latent_min_size or tile.shape[-2] > self.tile_latent_min_size):
decoded = self.spatial_tiled_decode(tile)
else:
decoded = self.decoder(tile)
row.append(decoded)
result_row = []
for i, tile in enumerate(row):
if i > 0:
tile = self.blend_t(row[i - 1], tile, blend_extent)
result_row.append(tile[:, :, :t_limit, :, :])
dec = torch.cat(result_row, dim=-3)
return dec
def encode(self, x: Tensor, return_dict: bool = True):
"""
Encodes the input by passing through the encoder network.
Support slicing and tiling for memory efficiency.
"""
def _encode(x):
if self.use_temporal_tiling and x.shape[-3] > self.tile_sample_min_tsize:
return self.temporal_tiled_encode(x)
if self.use_spatial_tiling and (
x.shape[-1] > self.tile_sample_min_size or x.shape[-2] > self.tile_sample_min_size):
return self.spatial_tiled_encode(x)
if self.use_compile:
@torch.compile
def encoder(x):
return self.encoder(x)
return encoder(x)
return self.encoder(x)
if len(x.shape) != 5: # (B, C, T, H, W)
x = x[:, :, None]
assert len(x.shape) == 5 # (B, C, T, H, W)
if x.shape[2] == 1:
x = x.expand(-1, -1, self.ffactor_temporal, -1, -1)
else:
assert x.shape[2] != self.ffactor_temporal and x.shape[2] % self.ffactor_temporal == 0
if self.use_slicing and x.shape[0] > 1:
if self.slicing_bsz == 1:
encoded_slices = [_encode(x_slice) for x_slice in x.split(1)]
else:
sections = [self.slicing_bsz] * (x.shape[0] // self.slicing_bsz)
if x.shape[0] % self.slicing_bsz != 0:
sections.append(x.shape[0] % self.slicing_bsz)
encoded_slices = [_encode(x_slice) for x_slice in x.split(sections)]
h = torch.cat(encoded_slices)
else:
h = _encode(x)
posterior = DiagonalGaussianDistribution(h)
if not return_dict:
return (posterior,)
return AutoencoderKLOutput(latent_dist=posterior)
def decode(self, z: Tensor, return_dict: bool = True, generator=None):
"""
Decodes the input by passing through the decoder network.
Support slicing and tiling for memory efficiency.
"""
def _decode(z):
if self.use_temporal_tiling and z.shape[-3] > self.tile_latent_min_tsize:
return self.temporal_tiled_decode(z)
if self.use_spatial_tiling and (
z.shape[-1] > self.tile_latent_min_size or z.shape[-2] > self.tile_latent_min_size):
return self.spatial_tiled_decode(z)
return self.decoder(z)
if self.use_slicing and z.shape[0] > 1:
decoded_slices = [_decode(z_slice) for z_slice in z.split(1)]
decoded = torch.cat(decoded_slices)
else:
decoded = _decode(z)
if z.shape[-3] == 1:
decoded = decoded[:, :, -1:]
if not return_dict:
return (decoded,)
return DecoderOutput(sample=decoded)
def forward(
self,
sample: torch.Tensor,
sample_posterior: bool = False,
return_posterior: bool = True,
return_dict: bool = True
):
posterior = self.encode(sample).latent_dist
z = posterior.sample() if sample_posterior else posterior.mode()
dec = self.decode(z).sample
return DecoderOutput(sample=dec, posterior=posterior) if return_dict else (dec, posterior)
def random_reset_tiling(self, x: torch.Tensor):
if x.shape[-3] == 1:
self.disable_spatial_tiling()
self.disable_temporal_tiling()
return
# Use fixed shape here
min_sample_size = int(1 / self.tile_overlap_factor) * self.ffactor_spatial
min_sample_tsize = int(1 / self.tile_overlap_factor) * self.ffactor_temporal
sample_size = random.choice([None, 1 * min_sample_size, 2 * min_sample_size, 3 * min_sample_size])
if sample_size is None:
self.disable_spatial_tiling()
else:
self.tile_sample_min_size = sample_size
self.tile_latent_min_size = sample_size // self.ffactor_spatial
self.enable_spatial_tiling()
sample_tsize = random.choice([None, 1 * min_sample_tsize, 2 * min_sample_tsize, 3 * min_sample_tsize])
if sample_tsize is None:
self.disable_temporal_tiling()
else:
self.tile_sample_min_tsize = sample_tsize
self.tile_latent_min_tsize = sample_tsize // self.ffactor_temporal
self.enable_temporal_tiling()