# Adapted from https://github.com/huggingface/diffusers/blob/main/src/diffusers/models/unet_2d_blocks.py
import torch
from torch import nn
from .attention import Transformer3DModel
from .resnet import Downsample3D, ResnetBlock3D, Upsample3D, AlphaBlender
from .motion_module import get_motion_module
def get_down_block(
down_block_type,
num_layers,
in_channels,
out_channels,
temb_channels,
add_downsample,
resnet_eps,
resnet_act_fn,
attn_num_head_channels,
resnet_groups=None,
cross_attention_dim=None,
downsample_padding=None,
dual_cross_attention=False,
use_linear_projection=False,
only_cross_attention=False,
upcast_attention=False,
resnet_time_scale_shift="default",
unet_use_cross_frame_attention=None,
unet_use_temporal_attention=None,
use_inflated_groupnorm=None,
use_motion_module=None,
use_motion_resnet=None, # not used for current weight
motion_module_type=None,
motion_module_kwargs=None,
):
down_block_type = down_block_type[7:] if down_block_type.startswith(
"UNetRes") else down_block_type
if down_block_type == "DownBlock3D":
return DownBlock3D(
num_layers=num_layers,
in_channels=in_channels,
out_channels=out_channels,
temb_channels=temb_channels,
add_downsample=add_downsample,
resnet_eps=resnet_eps,
resnet_act_fn=resnet_act_fn,
resnet_groups=resnet_groups,
downsample_padding=downsample_padding,
resnet_time_scale_shift=resnet_time_scale_shift,
use_inflated_groupnorm=use_inflated_groupnorm,
use_motion_module=use_motion_module,
motion_module_type=motion_module_type,
motion_module_kwargs=motion_module_kwargs,
)
elif down_block_type == "CrossAttnDownBlock3D":
if cross_attention_dim is None:
raise ValueError(
"cross_attention_dim must be specified for CrossAttnDownBlock3D")
return CrossAttnDownBlock3D(
num_layers=num_layers,
in_channels=in_channels,
out_channels=out_channels,
temb_channels=temb_channels,
add_downsample=add_downsample,
resnet_eps=resnet_eps,
resnet_act_fn=resnet_act_fn,
resnet_groups=resnet_groups,
downsample_padding=downsample_padding,
cross_attention_dim=cross_attention_dim,
attn_num_head_channels=attn_num_head_channels,
dual_cross_attention=dual_cross_attention,
use_linear_projection=use_linear_projection,
only_cross_attention=only_cross_attention,
upcast_attention=upcast_attention,
resnet_time_scale_shift=resnet_time_scale_shift,
unet_use_cross_frame_attention=unet_use_cross_frame_attention,
unet_use_temporal_attention=unet_use_temporal_attention,
use_inflated_groupnorm=use_inflated_groupnorm,
use_motion_module=use_motion_module,
use_motion_resnet=use_motion_resnet,
motion_module_type=motion_module_type,
motion_module_kwargs=motion_module_kwargs,
)
raise ValueError(f"{down_block_type} does not exist.")
def get_up_block(
up_block_type,
num_layers,
in_channels,
out_channels,
prev_output_channel,
temb_channels,
add_upsample,
resnet_eps,
resnet_act_fn,
attn_num_head_channels,
resnet_groups=None,
cross_attention_dim=None,
dual_cross_attention=False,
use_linear_projection=False,
only_cross_attention=False,
upcast_attention=False,
resnet_time_scale_shift="default",
unet_use_cross_frame_attention=None,
unet_use_temporal_attention=None,
use_inflated_groupnorm=None,
use_motion_module=None,
use_motion_resnet=None,
motion_module_type=None,
motion_module_kwargs=None,
):
up_block_type = up_block_type[7:] if up_block_type.startswith(
"UNetRes") else up_block_type
if up_block_type == "UpBlock3D":
return UpBlock3D(
num_layers=num_layers,
in_channels=in_channels,
out_channels=out_channels,
prev_output_channel=prev_output_channel,
temb_channels=temb_channels,
add_upsample=add_upsample,
resnet_eps=resnet_eps,
resnet_act_fn=resnet_act_fn,
resnet_groups=resnet_groups,
resnet_time_scale_shift=resnet_time_scale_shift,
use_inflated_groupnorm=use_inflated_groupnorm,
use_motion_module=use_motion_module,
motion_module_type=motion_module_type,
motion_module_kwargs=motion_module_kwargs,
)
elif up_block_type == "CrossAttnUpBlock3D":
if cross_attention_dim is None:
raise ValueError(
"cross_attention_dim must be specified for CrossAttnUpBlock3D")
return CrossAttnUpBlock3D(
num_layers=num_layers,
in_channels=in_channels,
out_channels=out_channels,
prev_output_channel=prev_output_channel,
temb_channels=temb_channels,
add_upsample=add_upsample,
resnet_eps=resnet_eps,
resnet_act_fn=resnet_act_fn,
resnet_groups=resnet_groups,
cross_attention_dim=cross_attention_dim,
attn_num_head_channels=attn_num_head_channels,
dual_cross_attention=dual_cross_attention,
use_linear_projection=use_linear_projection,
only_cross_attention=only_cross_attention,
upcast_attention=upcast_attention,
resnet_time_scale_shift=resnet_time_scale_shift,
unet_use_cross_frame_attention=unet_use_cross_frame_attention,
unet_use_temporal_attention=unet_use_temporal_attention,
use_inflated_groupnorm=use_inflated_groupnorm,
use_motion_module=use_motion_module,
use_motion_resnet=use_motion_resnet,
motion_module_type=motion_module_type,
motion_module_kwargs=motion_module_kwargs,
)
raise ValueError(f"{up_block_type} does not exist.")
class UNetMidBlock3DCrossAttn(nn.Module):
def __init__(
self,
in_channels: int,
temb_channels: int,
dropout: float = 0.0,
num_layers: int = 1,
resnet_eps: float = 1e-6,
resnet_time_scale_shift: str = "default",
resnet_act_fn: str = "swish",
resnet_groups: int = 32,
resnet_pre_norm: bool = True,
attn_num_head_channels=1,
output_scale_factor=1.0,
cross_attention_dim=1280,
dual_cross_attention=False,
use_linear_projection=False,
upcast_attention=False,
unet_use_cross_frame_attention=None,
unet_use_temporal_attention=None,
use_inflated_groupnorm=None,
use_motion_module=None,
use_motion_resnet=None,
motion_module_type=None,
motion_module_kwargs=None,
):
super().__init__()
self.has_cross_attention = True
self.attn_num_head_channels = attn_num_head_channels
resnet_groups = resnet_groups if resnet_groups is not None else min(
in_channels // 4, 32)
# there is always at least one resnet
resnets = [
ResnetBlock3D(
in_channels=in_channels,
out_channels=in_channels,
temb_channels=temb_channels,
eps=resnet_eps,
groups=resnet_groups,
dropout=dropout,
time_embedding_norm=resnet_time_scale_shift,
non_linearity=resnet_act_fn,
output_scale_factor=output_scale_factor,
pre_norm=resnet_pre_norm,
use_inflated_groupnorm=use_inflated_groupnorm,
)
]
motion_resnets = [
ResnetBlock3D(
in_channels=in_channels,
out_channels=in_channels,
temb_channels=temb_channels,
eps=resnet_eps,
groups=resnet_groups,
dropout=dropout,
time_embedding_norm=resnet_time_scale_shift,
non_linearity=resnet_act_fn,
output_scale_factor=output_scale_factor,
pre_norm=resnet_pre_norm,
use_inflated_groupnorm=use_inflated_groupnorm,
use_temporal_conv=True,
use_temporal_mixer=True,
) if use_motion_resnet else None
]
attentions = []
motion_modules = []
for _ in range(num_layers):
if dual_cross_attention:
raise NotImplementedError
attentions.append(
Transformer3DModel(
attn_num_head_channels,
in_channels // attn_num_head_channels,
in_channels=in_channels,
num_layers=1,
cross_attention_dim=cross_attention_dim,
norm_num_groups=resnet_groups,
use_linear_projection=use_linear_projection,
upcast_attention=upcast_attention,
unet_use_cross_frame_attention=unet_use_cross_frame_attention,
unet_use_temporal_attention=unet_use_temporal_attention,
)
)
motion_modules.append(
get_motion_module(
in_channels=in_channels,
motion_module_type=motion_module_type,
motion_module_kwargs=motion_module_kwargs,
) if use_motion_module else None
)
resnets.append(
ResnetBlock3D(
in_channels=in_channels,
out_channels=in_channels,
temb_channels=temb_channels,
eps=resnet_eps,
groups=resnet_groups,
dropout=dropout,
time_embedding_norm=resnet_time_scale_shift,
non_linearity=resnet_act_fn,
output_scale_factor=output_scale_factor,
pre_norm=resnet_pre_norm,
use_inflated_groupnorm=use_inflated_groupnorm,
)
)
motion_resnets.append(
ResnetBlock3D(
in_channels=in_channels,
out_channels=in_channels,
temb_channels=temb_channels,
eps=resnet_eps,
groups=resnet_groups,
dropout=dropout,
time_embedding_norm=resnet_time_scale_shift,
non_linearity=resnet_act_fn,
output_scale_factor=output_scale_factor,
pre_norm=resnet_pre_norm,
use_inflated_groupnorm=use_inflated_groupnorm,
use_temporal_conv=True,
use_temporal_mixer=True,
) if use_motion_resnet else None
)
self.attentions = nn.ModuleList(attentions)
self.resnets = nn.ModuleList(resnets)
self.motion_modules = nn.ModuleList(motion_modules)
self.motion_resnets = nn.ModuleList(motion_resnets)
def forward(self, hidden_states, temb=None, encoder_hidden_states=None, attention_mask=None):
hidden_states = self.resnets[0](hidden_states, temb)
hidden_states = self.motion_resnets[0](
hidden_states, temb) if self.motion_resnets[0] is not None else hidden_states
for attn, resnet, motion_module, motion_resnet in zip(self.attentions, self.resnets[1:], self.motion_modules, self.motion_resnets[1:]):
hidden_states = attn(
hidden_states, encoder_hidden_states=encoder_hidden_states).sample
hidden_states = motion_module(
hidden_states, temb, encoder_hidden_states=encoder_hidden_states) if motion_module is not None else hidden_states
hidden_states = resnet(hidden_states, temb)
hidden_states = motion_resnet(
hidden_states, temb) if motion_resnet is not None else hidden_states
return hidden_states
class CrossAttnDownBlock3D(nn.Module):
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_time_scale_shift: str = "default",
resnet_act_fn: str = "swish",
resnet_groups: int = 32,
resnet_pre_norm: bool = True,
attn_num_head_channels=1,
cross_attention_dim=1280,
output_scale_factor=1.0,
downsample_padding=1,
add_downsample=True,
dual_cross_attention=False,
use_linear_projection=False,
only_cross_attention=False,
upcast_attention=False,
unet_use_cross_frame_attention=None,
unet_use_temporal_attention=None,
use_inflated_groupnorm=None,
use_motion_module=None,
use_motion_resnet=None,
motion_module_type=None,
motion_module_kwargs=None,
):
super().__init__()
resnets = []
motion_resnets = []
attentions = []
motion_modules = []
self.has_cross_attention = True
self.attn_num_head_channels = attn_num_head_channels
for i in range(num_layers):
in_channels = in_channels if i == 0 else out_channels
resnets.append(
ResnetBlock3D(
in_channels=in_channels,
out_channels=out_channels,
temb_channels=temb_channels,
eps=resnet_eps,
groups=resnet_groups,
dropout=dropout,
time_embedding_norm=resnet_time_scale_shift,
non_linearity=resnet_act_fn,
output_scale_factor=output_scale_factor,
pre_norm=resnet_pre_norm,
use_inflated_groupnorm=use_inflated_groupnorm,
)
)
motion_resnets.append(
ResnetBlock3D(
in_channels=out_channels,
out_channels=out_channels,
temb_channels=temb_channels,
eps=resnet_eps,
groups=resnet_groups,
dropout=dropout,
time_embedding_norm=resnet_time_scale_shift,
non_linearity=resnet_act_fn,
output_scale_factor=output_scale_factor,
pre_norm=resnet_pre_norm,
use_inflated_groupnorm=use_inflated_groupnorm,
use_temporal_conv=True,
use_temporal_mixer=True,
) if use_motion_resnet else None
)
if dual_cross_attention:
raise NotImplementedError
attentions.append(
Transformer3DModel(
attn_num_head_channels,
out_channels // attn_num_head_channels,
in_channels=out_channels,
num_layers=1,
cross_attention_dim=cross_attention_dim,
norm_num_groups=resnet_groups,
use_linear_projection=use_linear_projection,
only_cross_attention=only_cross_attention,
upcast_attention=upcast_attention,
unet_use_cross_frame_attention=unet_use_cross_frame_attention,
unet_use_temporal_attention=unet_use_temporal_attention,
)
)
motion_modules.append(
get_motion_module(
in_channels=out_channels,
motion_module_type=motion_module_type,
motion_module_kwargs=motion_module_kwargs,
) if use_motion_module else None
)
self.attentions = nn.ModuleList(attentions)
self.resnets = nn.ModuleList(resnets)
self.motion_modules = nn.ModuleList(motion_modules)
self.motion_resnets = nn.ModuleList(motion_resnets)
if add_downsample:
self.downsamplers = nn.ModuleList(
[
Downsample3D(
out_channels, use_conv=True, out_channels=out_channels, padding=downsample_padding, name="op"
)
]
)
else:
self.downsamplers = None
self.gradient_checkpointing = False
def forward(self, hidden_states, temb=None, encoder_hidden_states=None, attention_mask=None, img_feature=None):
output_states = ()
idx = 1
for resnet, attn, motion_module, motion_resnet in zip(self.resnets, self.attentions, self.motion_modules, self.motion_resnets):
if self.training and self.gradient_checkpointing:
def create_custom_forward(module, return_dict=None):
def custom_forward(*inputs):
if return_dict is not None:
return module(*inputs, return_dict=return_dict)
else:
return module(*inputs)
return custom_forward
hidden_states = torch.utils.checkpoint.checkpoint(create_custom_forward(
resnet), hidden_states.requires_grad_(), temb, use_reentrant=False)
if motion_resnet is not None:
hidden_states = torch.utils.checkpoint.checkpoint(create_custom_forward(
motion_resnet), hidden_states.requires_grad_(), temb, use_reentrant=False)
hidden_states = torch.utils.checkpoint.checkpoint(
create_custom_forward(attn, return_dict=False),
hidden_states.requires_grad_(),
encoder_hidden_states,
use_reentrant=False
)[0]
hidden_states = hidden_states + \
img_feature if (
img_feature is not None and idx == 2) else hidden_states
if motion_module is not None:
hidden_states = torch.utils.checkpoint.checkpoint(create_custom_forward(
motion_module), hidden_states.requires_grad_(), temb, encoder_hidden_states, use_reentrant=False)
else:
hidden_states = resnet(hidden_states, temb)
hidden_states = motion_resnet(
hidden_states, temb) if motion_resnet is not None else hidden_states
hidden_states = attn(
hidden_states, encoder_hidden_states=encoder_hidden_states).sample
hidden_states = hidden_states + \
img_feature if (
img_feature is not None and idx == 2) else hidden_states
# add motion module
hidden_states = motion_module(
hidden_states, temb, encoder_hidden_states=encoder_hidden_states) if motion_module is not None else hidden_states
idx += 1
output_states += (hidden_states,)
if self.downsamplers is not None:
for downsampler in self.downsamplers:
hidden_states = downsampler(hidden_states)
output_states += (hidden_states,)
return hidden_states, output_states
class DownBlock3D(nn.Module):
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_time_scale_shift: str = "default",
resnet_act_fn: str = "swish",
resnet_groups: int = 32,
resnet_pre_norm: bool = True,
output_scale_factor=1.0,
add_downsample=True,
downsample_padding=1,
use_inflated_groupnorm=None,
use_motion_module=None,
motion_module_type=None,
motion_module_kwargs=None,
):
super().__init__()
resnets = []
motion_modules = []
for i in range(num_layers):
in_channels = in_channels if i == 0 else out_channels
resnets.append(
ResnetBlock3D(
in_channels=in_channels,
out_channels=out_channels,
temb_channels=temb_channels,
eps=resnet_eps,
groups=resnet_groups,
dropout=dropout,
time_embedding_norm=resnet_time_scale_shift,
non_linearity=resnet_act_fn,
output_scale_factor=output_scale_factor,
pre_norm=resnet_pre_norm,
use_inflated_groupnorm=use_inflated_groupnorm,
)
)
motion_modules.append(
get_motion_module(
in_channels=out_channels,
motion_module_type=motion_module_type,
motion_module_kwargs=motion_module_kwargs,
) if use_motion_module else None
)
self.resnets = nn.ModuleList(resnets)
self.motion_modules = nn.ModuleList(motion_modules)
if add_downsample:
self.downsamplers = nn.ModuleList(
[
Downsample3D(
out_channels, use_conv=True, out_channels=out_channels, padding=downsample_padding, name="op"
)
]
)
else:
self.downsamplers = None
self.gradient_checkpointing = False
def forward(self, hidden_states, temb=None, encoder_hidden_states=None, img_feature=None):
output_states = ()
idx = 1
for resnet, motion_module in zip(self.resnets, self.motion_modules):
if self.training and self.gradient_checkpointing:
def create_custom_forward(module):
def custom_forward(*inputs):
return module(*inputs)
return custom_forward
hidden_states = torch.utils.checkpoint.checkpoint(create_custom_forward(
resnet), hidden_states.requires_grad_(), temb, use_reentrant=False)
hidden_states = hidden_states + \
img_feature if (
img_feature is not None and idx == 2) else hidden_states
if motion_module is not None:
hidden_states = torch.utils.checkpoint.checkpoint(create_custom_forward(
motion_module), hidden_states.requires_grad_(), temb, encoder_hidden_states, use_reentrant=False)
else:
hidden_states = resnet(hidden_states, temb)
hidden_states = hidden_states + \
img_feature if (
img_feature is not None and idx == 2) else hidden_states
# add motion module
hidden_states = motion_module(
hidden_states, temb, encoder_hidden_states=encoder_hidden_states) if motion_module is not None else hidden_states
output_states += (hidden_states,)
idx += 1
if self.downsamplers is not None:
for downsampler in self.downsamplers:
hidden_states = downsampler(hidden_states)
output_states += (hidden_states,)
return hidden_states, output_states
class CrossAttnUpBlock3D(nn.Module):
def __init__(
self,
in_channels: int,
out_channels: int,
prev_output_channel: int,
temb_channels: int,
dropout: float = 0.0,
num_layers: int = 1,
resnet_eps: float = 1e-6,
resnet_time_scale_shift: str = "default",
resnet_act_fn: str = "swish",
resnet_groups: int = 32,
resnet_pre_norm: bool = True,
attn_num_head_channels=1,
cross_attention_dim=1280,
output_scale_factor=1.0,
add_upsample=True,
dual_cross_attention=False,
use_linear_projection=False,
only_cross_attention=False,
upcast_attention=False,
unet_use_cross_frame_attention=None,
unet_use_temporal_attention=None,
use_inflated_groupnorm=None,
use_motion_module=None,
use_motion_resnet=None,
motion_module_type=None,
motion_module_kwargs=None,
):
super().__init__()
resnets = []
attentions = []
motion_modules = []
motion_resnets = []
self.has_cross_attention = True
self.attn_num_head_channels = attn_num_head_channels
for i in range(num_layers):
res_skip_channels = in_channels if (
i == num_layers - 1) else out_channels
resnet_in_channels = prev_output_channel if i == 0 else out_channels
resnets.append(
ResnetBlock3D(
in_channels=resnet_in_channels + res_skip_channels,
out_channels=out_channels,
temb_channels=temb_channels,
eps=resnet_eps,
groups=resnet_groups,
dropout=dropout,
time_embedding_norm=resnet_time_scale_shift,
non_linearity=resnet_act_fn,
output_scale_factor=output_scale_factor,
pre_norm=resnet_pre_norm,
use_inflated_groupnorm=use_inflated_groupnorm,
)
)
motion_resnets.append(
ResnetBlock3D(
in_channels=out_channels,
out_channels=out_channels,
temb_channels=temb_channels,
eps=resnet_eps,
groups=resnet_groups,
dropout=dropout,
time_embedding_norm=resnet_time_scale_shift,
non_linearity=resnet_act_fn,
output_scale_factor=output_scale_factor,
pre_norm=resnet_pre_norm,
use_inflated_groupnorm=use_inflated_groupnorm,
use_temporal_conv=True,
use_temporal_mixer=True
) if use_motion_resnet else None
)
if dual_cross_attention:
raise NotImplementedError
attentions.append(
Transformer3DModel(
attn_num_head_channels,
out_channels // attn_num_head_channels,
in_channels=out_channels,
num_layers=1,
cross_attention_dim=cross_attention_dim,
norm_num_groups=resnet_groups,
use_linear_projection=use_linear_projection,
only_cross_attention=only_cross_attention,
upcast_attention=upcast_attention,
unet_use_cross_frame_attention=unet_use_cross_frame_attention,
unet_use_temporal_attention=unet_use_temporal_attention,
)
)
motion_modules.append(
get_motion_module(
in_channels=out_channels,
motion_module_type=motion_module_type,
motion_module_kwargs=motion_module_kwargs,
) if use_motion_module else None
)
self.attentions = nn.ModuleList(attentions)
self.resnets = nn.ModuleList(resnets)
self.motion_modules = nn.ModuleList(motion_modules)
self.motion_resnets = nn.ModuleList(motion_resnets)
if add_upsample:
self.upsamplers = nn.ModuleList(
[Upsample3D(out_channels, use_conv=True, out_channels=out_channels)])
else:
self.upsamplers = None
self.gradient_checkpointing = False
def forward(
self,
hidden_states,
res_hidden_states_tuple,
temb=None,
encoder_hidden_states=None,
upsample_size=None,
attention_mask=None,
):
for resnet, attn, motion_module, motion_resnet in zip(self.resnets, self.attentions, self.motion_modules, self.motion_resnets):
# pop res hidden states
res_hidden_states = res_hidden_states_tuple[-1]
res_hidden_states_tuple = res_hidden_states_tuple[:-1]
hidden_states = torch.cat(
[hidden_states, res_hidden_states], dim=1)
if self.training and self.gradient_checkpointing:
def create_custom_forward(module, return_dict=None):
def custom_forward(*inputs):
if return_dict is not None:
return module(*inputs, return_dict=return_dict)
else:
return module(*inputs)
return custom_forward
hidden_states = torch.utils.checkpoint.checkpoint(create_custom_forward(
resnet), hidden_states.requires_grad_(), temb, use_reentrant=False)
if motion_resnet is not None:
hidden_states = torch.utils.checkpoint.checkpoint(create_custom_forward(
motion_resnet), hidden_states.requires_grad_(), temb, use_reentrant=False)
hidden_states = torch.utils.checkpoint.checkpoint(
create_custom_forward(attn, return_dict=False),
hidden_states.requires_grad_(),
encoder_hidden_states,
use_reentrant=False,
)[0]
if motion_module is not None:
hidden_states = torch.utils.checkpoint.checkpoint(create_custom_forward(
motion_module), hidden_states.requires_grad_(), temb, encoder_hidden_states, use_reentrant=False)
else:
hidden_states = resnet(hidden_states, temb)
hidden_states = motion_resnet(
hidden_states, temb) if motion_resnet is not None else hidden_states
hidden_states = attn(
hidden_states, encoder_hidden_states=encoder_hidden_states).sample
# add motion module
hidden_states = motion_module(
hidden_states, temb, encoder_hidden_states=encoder_hidden_states) if motion_module is not None else hidden_states
if self.upsamplers is not None:
for upsampler in self.upsamplers:
hidden_states = upsampler(hidden_states, upsample_size)
return hidden_states
class UpBlock3D(nn.Module):
def __init__(
self,
in_channels: int,
prev_output_channel: int,
out_channels: int,
temb_channels: int,
dropout: float = 0.0,
num_layers: int = 1,
resnet_eps: float = 1e-6,
resnet_time_scale_shift: str = "default",
resnet_act_fn: str = "swish",
resnet_groups: int = 32,
resnet_pre_norm: bool = True,
output_scale_factor=1.0,
add_upsample=True,
use_inflated_groupnorm=None,
use_motion_module=None,
motion_module_type=None,
motion_module_kwargs=None,
):
super().__init__()
resnets = []
motion_modules = []
for i in range(num_layers):
res_skip_channels = in_channels if (
i == num_layers - 1) else out_channels
resnet_in_channels = prev_output_channel if i == 0 else out_channels
resnets.append(
ResnetBlock3D(
in_channels=resnet_in_channels + res_skip_channels,
out_channels=out_channels,
temb_channels=temb_channels,
eps=resnet_eps,
groups=resnet_groups,
dropout=dropout,
time_embedding_norm=resnet_time_scale_shift,
non_linearity=resnet_act_fn,
output_scale_factor=output_scale_factor,
pre_norm=resnet_pre_norm,
use_inflated_groupnorm=use_inflated_groupnorm,
)
)
motion_modules.append(
get_motion_module(
in_channels=out_channels,
motion_module_type=motion_module_type,
motion_module_kwargs=motion_module_kwargs,
) if use_motion_module else None
)
self.resnets = nn.ModuleList(resnets)
self.motion_modules = nn.ModuleList(motion_modules)
if add_upsample:
self.upsamplers = nn.ModuleList(
[Upsample3D(out_channels, use_conv=True, out_channels=out_channels)])
else:
self.upsamplers = None
self.gradient_checkpointing = False
def forward(self, hidden_states, res_hidden_states_tuple, temb=None, upsample_size=None, encoder_hidden_states=None,):
for resnet, motion_module in zip(self.resnets, self.motion_modules):
# pop res hidden states
res_hidden_states = res_hidden_states_tuple[-1]
res_hidden_states_tuple = res_hidden_states_tuple[:-1]
hidden_states = torch.cat(
[hidden_states, res_hidden_states], dim=1)
if self.training and self.gradient_checkpointing:
def create_custom_forward(module):
def custom_forward(*inputs):
return module(*inputs)
return custom_forward
hidden_states = torch.utils.checkpoint.checkpoint(create_custom_forward(
resnet), hidden_states.requires_grad_(), temb, use_reentrant=False)
if motion_module is not None:
hidden_states = torch.utils.checkpoint.checkpoint(create_custom_forward(
motion_module), hidden_states.requires_grad_(), temb, encoder_hidden_states, use_reentrant=False)
else:
hidden_states = resnet(hidden_states, temb)
hidden_states = motion_module(
hidden_states, temb, encoder_hidden_states=encoder_hidden_states) if motion_module is not None else hidden_states
if self.upsamplers is not None:
for upsampler in self.upsamplers:
hidden_states = upsampler(hidden_states, upsample_size)
return hidden_states