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Running
on
Zero
from functools import partial | |
from typing import List, Optional, Union | |
from einops import rearrange | |
from ...modules.diffusionmodules.openaimodel import * | |
from ...modules.video_attention import SpatialVideoTransformer | |
from ...util import default | |
from .util import AlphaBlender | |
class VideoResBlock(ResBlock): | |
def __init__( | |
self, | |
channels: int, | |
emb_channels: int, | |
dropout: float, | |
video_kernel_size: Union[int, List[int]] = 3, | |
merge_strategy: str = "fixed", | |
merge_factor: float = 0.5, | |
out_channels: Optional[int] = None, | |
use_conv: bool = False, | |
use_scale_shift_norm: bool = False, | |
dims: int = 2, | |
use_checkpoint: bool = False, | |
up: bool = False, | |
down: bool = False, | |
): | |
super().__init__( | |
channels, | |
emb_channels, | |
dropout, | |
out_channels=out_channels, | |
use_conv=use_conv, | |
use_scale_shift_norm=use_scale_shift_norm, | |
dims=dims, | |
use_checkpoint=use_checkpoint, | |
up=up, | |
down=down, | |
) | |
self.time_stack = ResBlock( | |
default(out_channels, channels), | |
emb_channels, | |
dropout=dropout, | |
dims=3, | |
out_channels=default(out_channels, channels), | |
use_scale_shift_norm=False, | |
use_conv=False, | |
up=False, | |
down=False, | |
kernel_size=video_kernel_size, | |
use_checkpoint=use_checkpoint, | |
exchange_temb_dims=True, | |
) | |
self.time_mixer = AlphaBlender( | |
alpha=merge_factor, | |
merge_strategy=merge_strategy, | |
rearrange_pattern="b t -> b 1 t 1 1", | |
) | |
def forward( | |
self, | |
x: th.Tensor, | |
emb: th.Tensor, | |
num_video_frames: int, | |
image_only_indicator: Optional[th.Tensor] = None, | |
) -> th.Tensor: | |
x = super().forward(x, emb) | |
x_mix = rearrange(x, "(b t) c h w -> b c t h w", t=num_video_frames) | |
x = rearrange(x, "(b t) c h w -> b c t h w", t=num_video_frames) | |
x = self.time_stack( | |
x, rearrange(emb, "(b t) ... -> b t ...", t=num_video_frames) | |
) | |
x = self.time_mixer( | |
x_spatial=x_mix, x_temporal=x, image_only_indicator=image_only_indicator | |
) | |
x = rearrange(x, "b c t h w -> (b t) c h w") | |
return x | |
class VideoUNet(nn.Module): | |
def __init__( | |
self, | |
in_channels: int, | |
model_channels: int, | |
out_channels: int, | |
num_res_blocks: int, | |
attention_resolutions: int, | |
dropout: float = 0.0, | |
channel_mult: List[int] = (1, 2, 4, 8), | |
conv_resample: bool = True, | |
dims: int = 2, | |
num_classes: Optional[int] = None, | |
use_checkpoint: bool = False, | |
num_heads: int = -1, | |
num_head_channels: int = -1, | |
num_heads_upsample: int = -1, | |
use_scale_shift_norm: bool = False, | |
resblock_updown: bool = False, | |
transformer_depth: Union[List[int], int] = 1, | |
transformer_depth_middle: Optional[int] = None, | |
context_dim: Optional[int] = None, | |
time_downup: bool = False, | |
time_context_dim: Optional[int] = None, | |
extra_ff_mix_layer: bool = False, | |
use_spatial_context: bool = False, | |
merge_strategy: str = "fixed", | |
merge_factor: float = 0.5, | |
spatial_transformer_attn_type: str = "softmax", | |
video_kernel_size: Union[int, List[int]] = 3, | |
use_linear_in_transformer: bool = False, | |
adm_in_channels: Optional[int] = None, | |
disable_temporal_crossattention: bool = False, | |
max_ddpm_temb_period: int = 10000, | |
): | |
super().__init__() | |
assert context_dim is not None | |
if num_heads_upsample == -1: | |
num_heads_upsample = num_heads | |
if num_heads == -1: | |
assert num_head_channels != -1 | |
if num_head_channels == -1: | |
assert num_heads != -1 | |
self.in_channels = in_channels | |
self.model_channels = model_channels | |
self.out_channels = out_channels | |
if isinstance(transformer_depth, int): | |
transformer_depth = len(channel_mult) * [transformer_depth] | |
transformer_depth_middle = default( | |
transformer_depth_middle, transformer_depth[-1] | |
) | |
self.num_res_blocks = num_res_blocks | |
self.attention_resolutions = attention_resolutions | |
self.dropout = dropout | |
self.channel_mult = channel_mult | |
self.conv_resample = conv_resample | |
self.num_classes = num_classes | |
self.use_checkpoint = use_checkpoint | |
self.num_heads = num_heads | |
self.num_head_channels = num_head_channels | |
self.num_heads_upsample = num_heads_upsample | |
time_embed_dim = model_channels * 4 | |
self.time_embed = nn.Sequential( | |
linear(model_channels, time_embed_dim), | |
nn.SiLU(), | |
linear(time_embed_dim, time_embed_dim), | |
) | |
if self.num_classes is not None: | |
if isinstance(self.num_classes, int): | |
self.label_emb = nn.Embedding(num_classes, time_embed_dim) | |
elif self.num_classes == "continuous": | |
print("setting up linear c_adm embedding layer") | |
self.label_emb = nn.Linear(1, time_embed_dim) | |
elif self.num_classes == "timestep": | |
self.label_emb = nn.Sequential( | |
Timestep(model_channels), | |
nn.Sequential( | |
linear(model_channels, time_embed_dim), | |
nn.SiLU(), | |
linear(time_embed_dim, time_embed_dim), | |
), | |
) | |
elif self.num_classes == "sequential": | |
assert adm_in_channels is not None | |
self.label_emb = nn.Sequential( | |
nn.Sequential( | |
linear(adm_in_channels, time_embed_dim), | |
nn.SiLU(), | |
linear(time_embed_dim, time_embed_dim), | |
) | |
) | |
else: | |
raise ValueError() | |
self.input_blocks = nn.ModuleList( | |
[ | |
TimestepEmbedSequential( | |
conv_nd(dims, in_channels, model_channels, 3, padding=1) | |
) | |
] | |
) | |
self._feature_size = model_channels | |
input_block_chans = [model_channels] | |
ch = model_channels | |
ds = 1 | |
def get_attention_layer( | |
ch, | |
num_heads, | |
dim_head, | |
depth=1, | |
context_dim=None, | |
use_checkpoint=False, | |
disabled_sa=False, | |
): | |
return SpatialVideoTransformer( | |
ch, | |
num_heads, | |
dim_head, | |
depth=depth, | |
context_dim=context_dim, | |
time_context_dim=time_context_dim, | |
dropout=dropout, | |
ff_in=extra_ff_mix_layer, | |
use_spatial_context=use_spatial_context, | |
merge_strategy=merge_strategy, | |
merge_factor=merge_factor, | |
checkpoint=use_checkpoint, | |
use_linear=use_linear_in_transformer, | |
attn_mode=spatial_transformer_attn_type, | |
disable_self_attn=disabled_sa, | |
disable_temporal_crossattention=disable_temporal_crossattention, | |
max_time_embed_period=max_ddpm_temb_period, | |
) | |
def get_resblock( | |
merge_factor, | |
merge_strategy, | |
video_kernel_size, | |
ch, | |
time_embed_dim, | |
dropout, | |
out_ch, | |
dims, | |
use_checkpoint, | |
use_scale_shift_norm, | |
down=False, | |
up=False, | |
): | |
return VideoResBlock( | |
merge_factor=merge_factor, | |
merge_strategy=merge_strategy, | |
video_kernel_size=video_kernel_size, | |
channels=ch, | |
emb_channels=time_embed_dim, | |
dropout=dropout, | |
out_channels=out_ch, | |
dims=dims, | |
use_checkpoint=use_checkpoint, | |
use_scale_shift_norm=use_scale_shift_norm, | |
down=down, | |
up=up, | |
) | |
for level, mult in enumerate(channel_mult): | |
for _ in range(num_res_blocks): | |
layers = [ | |
get_resblock( | |
merge_factor=merge_factor, | |
merge_strategy=merge_strategy, | |
video_kernel_size=video_kernel_size, | |
ch=ch, | |
time_embed_dim=time_embed_dim, | |
dropout=dropout, | |
out_ch=mult * model_channels, | |
dims=dims, | |
use_checkpoint=use_checkpoint, | |
use_scale_shift_norm=use_scale_shift_norm, | |
) | |
] | |
ch = mult * model_channels | |
if ds in attention_resolutions: | |
if num_head_channels == -1: | |
dim_head = ch // num_heads | |
else: | |
num_heads = ch // num_head_channels | |
dim_head = num_head_channels | |
layers.append( | |
get_attention_layer( | |
ch, | |
num_heads, | |
dim_head, | |
depth=transformer_depth[level], | |
context_dim=context_dim, | |
use_checkpoint=use_checkpoint, | |
disabled_sa=False, | |
) | |
) | |
self.input_blocks.append(TimestepEmbedSequential(*layers)) | |
self._feature_size += ch | |
input_block_chans.append(ch) | |
if level != len(channel_mult) - 1: | |
ds *= 2 | |
out_ch = ch | |
self.input_blocks.append( | |
TimestepEmbedSequential( | |
get_resblock( | |
merge_factor=merge_factor, | |
merge_strategy=merge_strategy, | |
video_kernel_size=video_kernel_size, | |
ch=ch, | |
time_embed_dim=time_embed_dim, | |
dropout=dropout, | |
out_ch=out_ch, | |
dims=dims, | |
use_checkpoint=use_checkpoint, | |
use_scale_shift_norm=use_scale_shift_norm, | |
down=True, | |
) | |
if resblock_updown | |
else Downsample( | |
ch, | |
conv_resample, | |
dims=dims, | |
out_channels=out_ch, | |
third_down=time_downup, | |
) | |
) | |
) | |
ch = out_ch | |
input_block_chans.append(ch) | |
self._feature_size += ch | |
if num_head_channels == -1: | |
dim_head = ch // num_heads | |
else: | |
num_heads = ch // num_head_channels | |
dim_head = num_head_channels | |
self.middle_block = TimestepEmbedSequential( | |
get_resblock( | |
merge_factor=merge_factor, | |
merge_strategy=merge_strategy, | |
video_kernel_size=video_kernel_size, | |
ch=ch, | |
time_embed_dim=time_embed_dim, | |
out_ch=None, | |
dropout=dropout, | |
dims=dims, | |
use_checkpoint=use_checkpoint, | |
use_scale_shift_norm=use_scale_shift_norm, | |
), | |
get_attention_layer( | |
ch, | |
num_heads, | |
dim_head, | |
depth=transformer_depth_middle, | |
context_dim=context_dim, | |
use_checkpoint=use_checkpoint, | |
), | |
get_resblock( | |
merge_factor=merge_factor, | |
merge_strategy=merge_strategy, | |
video_kernel_size=video_kernel_size, | |
ch=ch, | |
out_ch=None, | |
time_embed_dim=time_embed_dim, | |
dropout=dropout, | |
dims=dims, | |
use_checkpoint=use_checkpoint, | |
use_scale_shift_norm=use_scale_shift_norm, | |
), | |
) | |
self._feature_size += ch | |
self.output_blocks = nn.ModuleList([]) | |
for level, mult in list(enumerate(channel_mult))[::-1]: | |
for i in range(num_res_blocks + 1): | |
ich = input_block_chans.pop() | |
layers = [ | |
get_resblock( | |
merge_factor=merge_factor, | |
merge_strategy=merge_strategy, | |
video_kernel_size=video_kernel_size, | |
ch=ch + ich, | |
time_embed_dim=time_embed_dim, | |
dropout=dropout, | |
out_ch=model_channels * mult, | |
dims=dims, | |
use_checkpoint=use_checkpoint, | |
use_scale_shift_norm=use_scale_shift_norm, | |
) | |
] | |
ch = model_channels * mult | |
if ds in attention_resolutions: | |
if num_head_channels == -1: | |
dim_head = ch // num_heads | |
else: | |
num_heads = ch // num_head_channels | |
dim_head = num_head_channels | |
layers.append( | |
get_attention_layer( | |
ch, | |
num_heads, | |
dim_head, | |
depth=transformer_depth[level], | |
context_dim=context_dim, | |
use_checkpoint=use_checkpoint, | |
disabled_sa=False, | |
) | |
) | |
if level and i == num_res_blocks: | |
out_ch = ch | |
ds //= 2 | |
layers.append( | |
get_resblock( | |
merge_factor=merge_factor, | |
merge_strategy=merge_strategy, | |
video_kernel_size=video_kernel_size, | |
ch=ch, | |
time_embed_dim=time_embed_dim, | |
dropout=dropout, | |
out_ch=out_ch, | |
dims=dims, | |
use_checkpoint=use_checkpoint, | |
use_scale_shift_norm=use_scale_shift_norm, | |
up=True, | |
) | |
if resblock_updown | |
else Upsample( | |
ch, | |
conv_resample, | |
dims=dims, | |
out_channels=out_ch, | |
third_up=time_downup, | |
) | |
) | |
self.output_blocks.append(TimestepEmbedSequential(*layers)) | |
self._feature_size += ch | |
self.out = nn.Sequential( | |
normalization(ch), | |
nn.SiLU(), | |
zero_module(conv_nd(dims, model_channels, out_channels, 3, padding=1)), | |
) | |
def forward( | |
self, | |
x: th.Tensor, | |
timesteps: th.Tensor, | |
context: Optional[th.Tensor] = None, | |
y: Optional[th.Tensor] = None, | |
time_context: Optional[th.Tensor] = None, | |
num_video_frames: Optional[int] = None, | |
image_only_indicator: Optional[th.Tensor] = None, | |
): | |
assert (y is not None) == ( | |
self.num_classes is not None | |
), "must specify y if and only if the model is class-conditional -> no, relax this TODO" | |
hs = [] | |
t_emb = timestep_embedding(timesteps, self.model_channels, repeat_only=False) | |
emb = self.time_embed(t_emb) | |
if self.num_classes is not None: | |
assert y.shape[0] == x.shape[0] | |
emb = emb + self.label_emb(y) | |
h = x | |
for module in self.input_blocks: | |
h = module( | |
h, | |
emb, | |
context=context, | |
image_only_indicator=image_only_indicator, | |
time_context=time_context, | |
num_video_frames=num_video_frames, | |
) | |
hs.append(h) | |
h = self.middle_block( | |
h, | |
emb, | |
context=context, | |
image_only_indicator=image_only_indicator, | |
time_context=time_context, | |
num_video_frames=num_video_frames, | |
) | |
for module in self.output_blocks: | |
h = th.cat([h, hs.pop()], dim=1) | |
h = module( | |
h, | |
emb, | |
context=context, | |
image_only_indicator=image_only_indicator, | |
time_context=time_context, | |
num_video_frames=num_video_frames, | |
) | |
h = h.type(x.dtype) | |
return self.out(h) | |