Commit ce34ef01 authored by mashun1's avatar mashun1
Browse files

dynamicrafter

parents
Pipeline #812 canceled with stages
import torch
from torch import nn, einsum
import torch.nn.functional as F
from einops import rearrange, repeat
from functools import partial
try:
import xformers
import xformers.ops
XFORMERS_IS_AVAILBLE = True
except:
XFORMERS_IS_AVAILBLE = False
from lvdm.common import (
checkpoint,
exists,
default,
)
from lvdm.basics import zero_module
class RelativePosition(nn.Module):
""" https://github.com/evelinehong/Transformer_Relative_Position_PyTorch/blob/master/relative_position.py """
def __init__(self, num_units, max_relative_position):
super().__init__()
self.num_units = num_units
self.max_relative_position = max_relative_position
self.embeddings_table = nn.Parameter(torch.Tensor(max_relative_position * 2 + 1, num_units))
nn.init.xavier_uniform_(self.embeddings_table)
def forward(self, length_q, length_k):
device = self.embeddings_table.device
range_vec_q = torch.arange(length_q, device=device)
range_vec_k = torch.arange(length_k, device=device)
distance_mat = range_vec_k[None, :] - range_vec_q[:, None]
distance_mat_clipped = torch.clamp(distance_mat, -self.max_relative_position, self.max_relative_position)
final_mat = distance_mat_clipped + self.max_relative_position
final_mat = final_mat.long()
embeddings = self.embeddings_table[final_mat]
return embeddings
class CrossAttention(nn.Module):
def __init__(self, query_dim, context_dim=None, heads=8, dim_head=64, dropout=0.,
relative_position=False, temporal_length=None, video_length=None, image_cross_attention=False, image_cross_attention_scale=1.0, image_cross_attention_scale_learnable=False, text_context_len=77):
super().__init__()
inner_dim = dim_head * heads
context_dim = default(context_dim, query_dim)
self.scale = dim_head**-0.5
self.heads = heads
self.dim_head = dim_head
self.to_q = nn.Linear(query_dim, inner_dim, bias=False)
self.to_k = nn.Linear(context_dim, inner_dim, bias=False)
self.to_v = nn.Linear(context_dim, inner_dim, bias=False)
self.to_out = nn.Sequential(nn.Linear(inner_dim, query_dim), nn.Dropout(dropout))
self.relative_position = relative_position
if self.relative_position:
assert(temporal_length is not None)
self.relative_position_k = RelativePosition(num_units=dim_head, max_relative_position=temporal_length)
self.relative_position_v = RelativePosition(num_units=dim_head, max_relative_position=temporal_length)
else:
## only used for spatial attention, while NOT for temporal attention
if XFORMERS_IS_AVAILBLE and temporal_length is None:
self.forward = self.efficient_forward
self.video_length = video_length
self.image_cross_attention = image_cross_attention
self.image_cross_attention_scale = image_cross_attention_scale
self.text_context_len = text_context_len
self.image_cross_attention_scale_learnable = image_cross_attention_scale_learnable
if self.image_cross_attention:
self.to_k_ip = nn.Linear(context_dim, inner_dim, bias=False)
self.to_v_ip = nn.Linear(context_dim, inner_dim, bias=False)
if image_cross_attention_scale_learnable:
self.register_parameter('alpha', nn.Parameter(torch.tensor(0.)) )
def forward(self, x, context=None, mask=None):
spatial_self_attn = (context is None)
k_ip, v_ip, out_ip = None, None, None
h = self.heads
q = self.to_q(x)
context = default(context, x)
if self.image_cross_attention and not spatial_self_attn:
context, context_image = context[:,:self.text_context_len,:], context[:,self.text_context_len:,:]
k = self.to_k(context)
v = self.to_v(context)
k_ip = self.to_k_ip(context_image)
v_ip = self.to_v_ip(context_image)
else:
if not spatial_self_attn:
context = context[:,:self.text_context_len,:]
k = self.to_k(context)
v = self.to_v(context)
q, k, v = map(lambda t: rearrange(t, 'b n (h d) -> (b h) n d', h=h), (q, k, v))
sim = torch.einsum('b i d, b j d -> b i j', q, k) * self.scale
if self.relative_position:
len_q, len_k, len_v = q.shape[1], k.shape[1], v.shape[1]
k2 = self.relative_position_k(len_q, len_k)
sim2 = einsum('b t d, t s d -> b t s', q, k2) * self.scale # TODO check
sim += sim2
del k
if exists(mask):
## feasible for causal attention mask only
max_neg_value = -torch.finfo(sim.dtype).max
mask = repeat(mask, 'b i j -> (b h) i j', h=h)
sim.masked_fill_(~(mask>0.5), max_neg_value)
# attention, what we cannot get enough of
sim = sim.softmax(dim=-1)
out = torch.einsum('b i j, b j d -> b i d', sim, v)
if self.relative_position:
v2 = self.relative_position_v(len_q, len_v)
out2 = einsum('b t s, t s d -> b t d', sim, v2) # TODO check
out += out2
out = rearrange(out, '(b h) n d -> b n (h d)', h=h)
## for image cross-attention
if k_ip is not None:
k_ip, v_ip = map(lambda t: rearrange(t, 'b n (h d) -> (b h) n d', h=h), (k_ip, v_ip))
sim_ip = torch.einsum('b i d, b j d -> b i j', q, k_ip) * self.scale
del k_ip
sim_ip = sim_ip.softmax(dim=-1)
out_ip = torch.einsum('b i j, b j d -> b i d', sim_ip, v_ip)
out_ip = rearrange(out_ip, '(b h) n d -> b n (h d)', h=h)
if out_ip is not None:
if self.image_cross_attention_scale_learnable:
out = out + self.image_cross_attention_scale * out_ip * (torch.tanh(self.alpha)+1)
else:
out = out + self.image_cross_attention_scale * out_ip
return self.to_out(out)
def efficient_forward(self, x, context=None, mask=None):
spatial_self_attn = (context is None)
k_ip, v_ip, out_ip = None, None, None
q = self.to_q(x)
context = default(context, x)
if self.image_cross_attention and not spatial_self_attn:
context, context_image = context[:,:self.text_context_len,:], context[:,self.text_context_len:,:]
k = self.to_k(context)
v = self.to_v(context)
k_ip = self.to_k_ip(context_image)
v_ip = self.to_v_ip(context_image)
else:
if not spatial_self_attn:
context = context[:,:self.text_context_len,:]
k = self.to_k(context)
v = self.to_v(context)
b, _, _ = q.shape
q, k, v = map(
lambda t: t.unsqueeze(3)
.reshape(b, t.shape[1], self.heads, self.dim_head)
.permute(0, 2, 1, 3)
.reshape(b * self.heads, t.shape[1], self.dim_head)
.contiguous(),
(q, k, v),
)
# actually compute the attention, what we cannot get enough of
out = xformers.ops.memory_efficient_attention(q, k, v, attn_bias=None, op=xformers.ops.fmha.MemoryEfficientAttentionFlashAttentionOp)
## for image cross-attention
if k_ip is not None:
k_ip, v_ip = map(
lambda t: t.unsqueeze(3)
.reshape(b, t.shape[1], self.heads, self.dim_head)
.permute(0, 2, 1, 3)
.reshape(b * self.heads, t.shape[1], self.dim_head)
.contiguous(),
(k_ip, v_ip),
)
out_ip = xformers.ops.memory_efficient_attention(q, k_ip, v_ip, attn_bias=None, op=xformers.ops.fmha.MemoryEfficientAttentionFlashAttentionOp)
out_ip = (
out_ip.unsqueeze(0)
.reshape(b, self.heads, out.shape[1], self.dim_head)
.permute(0, 2, 1, 3)
.reshape(b, out.shape[1], self.heads * self.dim_head)
)
if exists(mask):
raise NotImplementedError
out = (
out.unsqueeze(0)
.reshape(b, self.heads, out.shape[1], self.dim_head)
.permute(0, 2, 1, 3)
.reshape(b, out.shape[1], self.heads * self.dim_head)
)
if out_ip is not None:
if self.image_cross_attention_scale_learnable:
out = out + self.image_cross_attention_scale * out_ip * (torch.tanh(self.alpha)+1)
else:
out = out + self.image_cross_attention_scale * out_ip
return self.to_out(out)
class BasicTransformerBlock(nn.Module):
def __init__(self, dim, n_heads, d_head, dropout=0., context_dim=None, gated_ff=True, checkpoint=True,
disable_self_attn=False, attention_cls=None, video_length=None, image_cross_attention=False, image_cross_attention_scale=1.0, image_cross_attention_scale_learnable=False, text_context_len=77):
super().__init__()
attn_cls = CrossAttention if attention_cls is None else attention_cls
self.disable_self_attn = disable_self_attn
self.attn1 = attn_cls(query_dim=dim, heads=n_heads, dim_head=d_head, dropout=dropout,
context_dim=context_dim if self.disable_self_attn else None)
self.ff = FeedForward(dim, dropout=dropout, glu=gated_ff)
self.attn2 = attn_cls(query_dim=dim, context_dim=context_dim, heads=n_heads, dim_head=d_head, dropout=dropout, video_length=video_length, image_cross_attention=image_cross_attention, image_cross_attention_scale=image_cross_attention_scale, image_cross_attention_scale_learnable=image_cross_attention_scale_learnable,text_context_len=text_context_len)
self.image_cross_attention = image_cross_attention
self.norm1 = nn.LayerNorm(dim)
self.norm2 = nn.LayerNorm(dim)
self.norm3 = nn.LayerNorm(dim)
self.checkpoint = checkpoint
def forward(self, x, context=None, mask=None, **kwargs):
## implementation tricks: because checkpointing doesn't support non-tensor (e.g. None or scalar) arguments
input_tuple = (x,) ## should not be (x), otherwise *input_tuple will decouple x into multiple arguments
if context is not None:
input_tuple = (x, context)
if mask is not None:
forward_mask = partial(self._forward, mask=mask)
return checkpoint(forward_mask, (x,), self.parameters(), self.checkpoint)
return checkpoint(self._forward, input_tuple, self.parameters(), self.checkpoint)
def _forward(self, x, context=None, mask=None):
x = self.attn1(self.norm1(x), context=context if self.disable_self_attn else None, mask=mask) + x
x = self.attn2(self.norm2(x), context=context, mask=mask) + x
x = self.ff(self.norm3(x)) + x
return x
class SpatialTransformer(nn.Module):
"""
Transformer block for image-like data in spatial axis.
First, project the input (aka embedding)
and reshape to b, t, d.
Then apply standard transformer action.
Finally, reshape to image
NEW: use_linear for more efficiency instead of the 1x1 convs
"""
def __init__(self, in_channels, n_heads, d_head, depth=1, dropout=0., context_dim=None,
use_checkpoint=True, disable_self_attn=False, use_linear=False, video_length=None,
image_cross_attention=False, image_cross_attention_scale_learnable=False):
super().__init__()
self.in_channels = in_channels
inner_dim = n_heads * d_head
self.norm = torch.nn.GroupNorm(num_groups=32, num_channels=in_channels, eps=1e-6, affine=True)
if not use_linear:
self.proj_in = nn.Conv2d(in_channels, inner_dim, kernel_size=1, stride=1, padding=0)
else:
self.proj_in = nn.Linear(in_channels, inner_dim)
attention_cls = None
self.transformer_blocks = nn.ModuleList([
BasicTransformerBlock(
inner_dim,
n_heads,
d_head,
dropout=dropout,
context_dim=context_dim,
disable_self_attn=disable_self_attn,
checkpoint=use_checkpoint,
attention_cls=attention_cls,
video_length=video_length,
image_cross_attention=image_cross_attention,
image_cross_attention_scale_learnable=image_cross_attention_scale_learnable,
) for d in range(depth)
])
if not use_linear:
self.proj_out = zero_module(nn.Conv2d(inner_dim, in_channels, kernel_size=1, stride=1, padding=0))
else:
self.proj_out = zero_module(nn.Linear(inner_dim, in_channels))
self.use_linear = use_linear
def forward(self, x, context=None, **kwargs):
b, c, h, w = x.shape
x_in = x
x = self.norm(x)
if not self.use_linear:
x = self.proj_in(x)
x = rearrange(x, 'b c h w -> b (h w) c').contiguous()
if self.use_linear:
x = self.proj_in(x)
for i, block in enumerate(self.transformer_blocks):
x = block(x, context=context, **kwargs)
if self.use_linear:
x = self.proj_out(x)
x = rearrange(x, 'b (h w) c -> b c h w', h=h, w=w).contiguous()
if not self.use_linear:
x = self.proj_out(x)
return x + x_in
class TemporalTransformer(nn.Module):
"""
Transformer block for image-like data in temporal axis.
First, reshape to b, t, d.
Then apply standard transformer action.
Finally, reshape to image
"""
def __init__(self, in_channels, n_heads, d_head, depth=1, dropout=0., context_dim=None,
use_checkpoint=True, use_linear=False, only_self_att=True, causal_attention=False, causal_block_size=1,
relative_position=False, temporal_length=None):
super().__init__()
self.only_self_att = only_self_att
self.relative_position = relative_position
self.causal_attention = causal_attention
self.causal_block_size = causal_block_size
self.in_channels = in_channels
inner_dim = n_heads * d_head
self.norm = torch.nn.GroupNorm(num_groups=32, num_channels=in_channels, eps=1e-6, affine=True)
self.proj_in = nn.Conv1d(in_channels, inner_dim, kernel_size=1, stride=1, padding=0)
if not use_linear:
self.proj_in = nn.Conv1d(in_channels, inner_dim, kernel_size=1, stride=1, padding=0)
else:
self.proj_in = nn.Linear(in_channels, inner_dim)
if relative_position:
assert(temporal_length is not None)
attention_cls = partial(CrossAttention, relative_position=True, temporal_length=temporal_length)
else:
attention_cls = partial(CrossAttention, temporal_length=temporal_length)
if self.causal_attention:
assert(temporal_length is not None)
self.mask = torch.tril(torch.ones([1, temporal_length, temporal_length]))
if self.only_self_att:
context_dim = None
self.transformer_blocks = nn.ModuleList([
BasicTransformerBlock(
inner_dim,
n_heads,
d_head,
dropout=dropout,
context_dim=context_dim,
attention_cls=attention_cls,
checkpoint=use_checkpoint) for d in range(depth)
])
if not use_linear:
self.proj_out = zero_module(nn.Conv1d(inner_dim, in_channels, kernel_size=1, stride=1, padding=0))
else:
self.proj_out = zero_module(nn.Linear(inner_dim, in_channels))
self.use_linear = use_linear
def forward(self, x, context=None):
b, c, t, h, w = x.shape
x_in = x
x = self.norm(x)
x = rearrange(x, 'b c t h w -> (b h w) c t').contiguous()
if not self.use_linear:
x = self.proj_in(x)
x = rearrange(x, 'bhw c t -> bhw t c').contiguous()
if self.use_linear:
x = self.proj_in(x)
temp_mask = None
if self.causal_attention:
# slice the from mask map
temp_mask = self.mask[:,:t,:t].to(x.device)
if temp_mask is not None:
mask = temp_mask.to(x.device)
mask = repeat(mask, 'l i j -> (l bhw) i j', bhw=b*h*w)
else:
mask = None
if self.only_self_att:
## note: if no context is given, cross-attention defaults to self-attention
for i, block in enumerate(self.transformer_blocks):
x = block(x, mask=mask)
x = rearrange(x, '(b hw) t c -> b hw t c', b=b).contiguous()
else:
x = rearrange(x, '(b hw) t c -> b hw t c', b=b).contiguous()
context = rearrange(context, '(b t) l con -> b t l con', t=t).contiguous()
for i, block in enumerate(self.transformer_blocks):
# calculate each batch one by one (since number in shape could not greater then 65,535 for some package)
for j in range(b):
context_j = repeat(
context[j],
't l con -> (t r) l con', r=(h * w) // t, t=t).contiguous()
## note: causal mask will not applied in cross-attention case
x[j] = block(x[j], context=context_j)
if self.use_linear:
x = self.proj_out(x)
x = rearrange(x, 'b (h w) t c -> b c t h w', h=h, w=w).contiguous()
if not self.use_linear:
x = rearrange(x, 'b hw t c -> (b hw) c t').contiguous()
x = self.proj_out(x)
x = rearrange(x, '(b h w) c t -> b c t h w', b=b, h=h, w=w).contiguous()
return x + x_in
class GEGLU(nn.Module):
def __init__(self, dim_in, dim_out):
super().__init__()
self.proj = nn.Linear(dim_in, dim_out * 2)
def forward(self, x):
x, gate = self.proj(x).chunk(2, dim=-1)
return x * F.gelu(gate)
class FeedForward(nn.Module):
def __init__(self, dim, dim_out=None, mult=4, glu=False, dropout=0.):
super().__init__()
inner_dim = int(dim * mult)
dim_out = default(dim_out, dim)
project_in = nn.Sequential(
nn.Linear(dim, inner_dim),
nn.GELU()
) if not glu else GEGLU(dim, inner_dim)
self.net = nn.Sequential(
project_in,
nn.Dropout(dropout),
nn.Linear(inner_dim, dim_out)
)
def forward(self, x):
return self.net(x)
class LinearAttention(nn.Module):
def __init__(self, dim, heads=4, dim_head=32):
super().__init__()
self.heads = heads
hidden_dim = dim_head * heads
self.to_qkv = nn.Conv2d(dim, hidden_dim * 3, 1, bias = False)
self.to_out = nn.Conv2d(hidden_dim, dim, 1)
def forward(self, x):
b, c, h, w = x.shape
qkv = self.to_qkv(x)
q, k, v = rearrange(qkv, 'b (qkv heads c) h w -> qkv b heads c (h w)', heads = self.heads, qkv=3)
k = k.softmax(dim=-1)
context = torch.einsum('bhdn,bhen->bhde', k, v)
out = torch.einsum('bhde,bhdn->bhen', context, q)
out = rearrange(out, 'b heads c (h w) -> b (heads c) h w', heads=self.heads, h=h, w=w)
return self.to_out(out)
class SpatialSelfAttention(nn.Module):
def __init__(self, in_channels):
super().__init__()
self.in_channels = in_channels
self.norm = torch.nn.GroupNorm(num_groups=32, num_channels=in_channels, eps=1e-6, affine=True)
self.q = torch.nn.Conv2d(in_channels,
in_channels,
kernel_size=1,
stride=1,
padding=0)
self.k = torch.nn.Conv2d(in_channels,
in_channels,
kernel_size=1,
stride=1,
padding=0)
self.v = torch.nn.Conv2d(in_channels,
in_channels,
kernel_size=1,
stride=1,
padding=0)
self.proj_out = torch.nn.Conv2d(in_channels,
in_channels,
kernel_size=1,
stride=1,
padding=0)
def forward(self, x):
h_ = x
h_ = self.norm(h_)
q = self.q(h_)
k = self.k(h_)
v = self.v(h_)
# compute attention
b,c,h,w = q.shape
q = rearrange(q, 'b c h w -> b (h w) c')
k = rearrange(k, 'b c h w -> b c (h w)')
w_ = torch.einsum('bij,bjk->bik', q, k)
w_ = w_ * (int(c)**(-0.5))
w_ = torch.nn.functional.softmax(w_, dim=2)
# attend to values
v = rearrange(v, 'b c h w -> b c (h w)')
w_ = rearrange(w_, 'b i j -> b j i')
h_ = torch.einsum('bij,bjk->bik', v, w_)
h_ = rearrange(h_, 'b c (h w) -> b c h w', h=h)
h_ = self.proj_out(h_)
return x+h_
import torch
import torch.nn as nn
import kornia
import open_clip
from torch.utils.checkpoint import checkpoint
from transformers import T5Tokenizer, T5EncoderModel, CLIPTokenizer, CLIPTextModel
from lvdm.common import autocast
from utils.utils import count_params
class AbstractEncoder(nn.Module):
def __init__(self):
super().__init__()
def encode(self, *args, **kwargs):
raise NotImplementedError
class IdentityEncoder(AbstractEncoder):
def encode(self, x):
return x
class ClassEmbedder(nn.Module):
def __init__(self, embed_dim, n_classes=1000, key='class', ucg_rate=0.1):
super().__init__()
self.key = key
self.embedding = nn.Embedding(n_classes, embed_dim)
self.n_classes = n_classes
self.ucg_rate = ucg_rate
def forward(self, batch, key=None, disable_dropout=False):
if key is None:
key = self.key
# this is for use in crossattn
c = batch[key][:, None]
if self.ucg_rate > 0. and not disable_dropout:
mask = 1. - torch.bernoulli(torch.ones_like(c) * self.ucg_rate)
c = mask * c + (1 - mask) * torch.ones_like(c) * (self.n_classes - 1)
c = c.long()
c = self.embedding(c)
return c
def get_unconditional_conditioning(self, bs, device="cuda"):
uc_class = self.n_classes - 1 # 1000 classes --> 0 ... 999, one extra class for ucg (class 1000)
uc = torch.ones((bs,), device=device) * uc_class
uc = {self.key: uc}
return uc
def disabled_train(self, mode=True):
"""Overwrite model.train with this function to make sure train/eval mode
does not change anymore."""
return self
class FrozenT5Embedder(AbstractEncoder):
"""Uses the T5 transformer encoder for text"""
def __init__(self, version="google/t5-v1_1-large", device="cuda", max_length=77,
freeze=True): # others are google/t5-v1_1-xl and google/t5-v1_1-xxl
super().__init__()
self.tokenizer = T5Tokenizer.from_pretrained(version)
self.transformer = T5EncoderModel.from_pretrained(version)
self.device = device
self.max_length = max_length # TODO: typical value?
if freeze:
self.freeze()
def freeze(self):
self.transformer = self.transformer.eval()
# self.train = disabled_train
for param in self.parameters():
param.requires_grad = False
def forward(self, text):
batch_encoding = self.tokenizer(text, truncation=True, max_length=self.max_length, return_length=True,
return_overflowing_tokens=False, padding="max_length", return_tensors="pt")
tokens = batch_encoding["input_ids"].to(self.device)
outputs = self.transformer(input_ids=tokens)
z = outputs.last_hidden_state
return z
def encode(self, text):
return self(text)
class FrozenCLIPEmbedder(AbstractEncoder):
"""Uses the CLIP transformer encoder for text (from huggingface)"""
LAYERS = [
"last",
"pooled",
"hidden"
]
def __init__(self, version="openai/clip-vit-large-patch14", device="cuda", max_length=77,
freeze=True, layer="last", layer_idx=None): # clip-vit-base-patch32
super().__init__()
assert layer in self.LAYERS
self.tokenizer = CLIPTokenizer.from_pretrained(version)
self.transformer = CLIPTextModel.from_pretrained(version)
self.device = device
self.max_length = max_length
if freeze:
self.freeze()
self.layer = layer
self.layer_idx = layer_idx
if layer == "hidden":
assert layer_idx is not None
assert 0 <= abs(layer_idx) <= 12
def freeze(self):
self.transformer = self.transformer.eval()
# self.train = disabled_train
for param in self.parameters():
param.requires_grad = False
def forward(self, text):
batch_encoding = self.tokenizer(text, truncation=True, max_length=self.max_length, return_length=True,
return_overflowing_tokens=False, padding="max_length", return_tensors="pt")
tokens = batch_encoding["input_ids"].to(self.device)
outputs = self.transformer(input_ids=tokens, output_hidden_states=self.layer == "hidden")
if self.layer == "last":
z = outputs.last_hidden_state
elif self.layer == "pooled":
z = outputs.pooler_output[:, None, :]
else:
z = outputs.hidden_states[self.layer_idx]
return z
def encode(self, text):
return self(text)
class ClipImageEmbedder(nn.Module):
def __init__(
self,
model,
jit=False,
device='cuda' if torch.cuda.is_available() else 'cpu',
antialias=True,
ucg_rate=0.
):
super().__init__()
from clip import load as load_clip
self.model, _ = load_clip(name=model, device=device, jit=jit)
self.antialias = antialias
self.register_buffer('mean', torch.Tensor([0.48145466, 0.4578275, 0.40821073]), persistent=False)
self.register_buffer('std', torch.Tensor([0.26862954, 0.26130258, 0.27577711]), persistent=False)
self.ucg_rate = ucg_rate
def preprocess(self, x):
# normalize to [0,1]
x = kornia.geometry.resize(x, (224, 224),
interpolation='bicubic', align_corners=True,
antialias=self.antialias)
x = (x + 1.) / 2.
# re-normalize according to clip
x = kornia.enhance.normalize(x, self.mean, self.std)
return x
def forward(self, x, no_dropout=False):
# x is assumed to be in range [-1,1]
out = self.model.encode_image(self.preprocess(x))
out = out.to(x.dtype)
if self.ucg_rate > 0. and not no_dropout:
out = torch.bernoulli((1. - self.ucg_rate) * torch.ones(out.shape[0], device=out.device))[:, None] * out
return out
class FrozenOpenCLIPEmbedder(AbstractEncoder):
"""
Uses the OpenCLIP transformer encoder for text
"""
LAYERS = [
# "pooled",
"last",
"penultimate"
]
def __init__(self, arch="ViT-H-14", version="laion2b_s32b_b79k", device="cuda", max_length=77,
freeze=True, layer="last"):
super().__init__()
assert layer in self.LAYERS
model, _, _ = open_clip.create_model_and_transforms(arch, device=torch.device('cpu'), pretrained=version)
del model.visual
self.model = model
self.device = device
self.max_length = max_length
if freeze:
self.freeze()
self.layer = layer
if self.layer == "last":
self.layer_idx = 0
elif self.layer == "penultimate":
self.layer_idx = 1
else:
raise NotImplementedError()
def freeze(self):
self.model = self.model.eval()
for param in self.parameters():
param.requires_grad = False
def forward(self, text):
tokens = open_clip.tokenize(text) ## all clip models use 77 as context length
z = self.encode_with_transformer(tokens.to(self.device))
return z
def encode_with_transformer(self, text):
x = self.model.token_embedding(text) # [batch_size, n_ctx, d_model]
x = x + self.model.positional_embedding
x = x.permute(1, 0, 2) # NLD -> LND
x = self.text_transformer_forward(x, attn_mask=self.model.attn_mask)
x = x.permute(1, 0, 2) # LND -> NLD
x = self.model.ln_final(x)
return x
def text_transformer_forward(self, x: torch.Tensor, attn_mask=None):
for i, r in enumerate(self.model.transformer.resblocks):
if i == len(self.model.transformer.resblocks) - self.layer_idx:
break
if self.model.transformer.grad_checkpointing and not torch.jit.is_scripting():
x = checkpoint(r, x, attn_mask)
else:
x = r(x, attn_mask=attn_mask)
return x
def encode(self, text):
return self(text)
class FrozenOpenCLIPImageEmbedder(AbstractEncoder):
"""
Uses the OpenCLIP vision transformer encoder for images
"""
def __init__(self, arch="ViT-H-14", version="laion2b_s32b_b79k", device="cuda", max_length=77,
freeze=True, layer="pooled", antialias=True, ucg_rate=0.):
super().__init__()
model, _, _ = open_clip.create_model_and_transforms(arch, device=torch.device('cpu'),
pretrained=version, )
del model.transformer
self.model = model
# self.mapper = torch.nn.Linear(1280, 1024)
self.device = device
self.max_length = max_length
if freeze:
self.freeze()
self.layer = layer
if self.layer == "penultimate":
raise NotImplementedError()
self.layer_idx = 1
self.antialias = antialias
self.register_buffer('mean', torch.Tensor([0.48145466, 0.4578275, 0.40821073]), persistent=False)
self.register_buffer('std', torch.Tensor([0.26862954, 0.26130258, 0.27577711]), persistent=False)
self.ucg_rate = ucg_rate
def preprocess(self, x):
# normalize to [0,1]
x = kornia.geometry.resize(x, (224, 224),
interpolation='bicubic', align_corners=True,
antialias=self.antialias)
x = (x + 1.) / 2.
# renormalize according to clip
x = kornia.enhance.normalize(x, self.mean, self.std)
return x
def freeze(self):
self.model = self.model.eval()
for param in self.model.parameters():
param.requires_grad = False
@autocast
def forward(self, image, no_dropout=False):
z = self.encode_with_vision_transformer(image)
if self.ucg_rate > 0. and not no_dropout:
z = torch.bernoulli((1. - self.ucg_rate) * torch.ones(z.shape[0], device=z.device))[:, None] * z
return z
def encode_with_vision_transformer(self, img):
img = self.preprocess(img)
x = self.model.visual(img)
return x
def encode(self, text):
return self(text)
class FrozenOpenCLIPImageEmbedderV2(AbstractEncoder):
"""
Uses the OpenCLIP vision transformer encoder for images
"""
def __init__(self, arch="ViT-H-14", version="laion2b_s32b_b79k", device="cuda",
freeze=True, layer="pooled", antialias=True):
super().__init__()
model, _, _ = open_clip.create_model_and_transforms(arch, device=torch.device('cpu'),
pretrained=version, )
del model.transformer
self.model = model
self.device = device
if freeze:
self.freeze()
self.layer = layer
if self.layer == "penultimate":
raise NotImplementedError()
self.layer_idx = 1
self.antialias = antialias
self.register_buffer('mean', torch.Tensor([0.48145466, 0.4578275, 0.40821073]), persistent=False)
self.register_buffer('std', torch.Tensor([0.26862954, 0.26130258, 0.27577711]), persistent=False)
def preprocess(self, x):
# normalize to [0,1]
x = kornia.geometry.resize(x, (224, 224),
interpolation='bicubic', align_corners=True,
antialias=self.antialias)
x = (x + 1.) / 2.
# renormalize according to clip
x = kornia.enhance.normalize(x, self.mean, self.std)
return x
def freeze(self):
self.model = self.model.eval()
for param in self.model.parameters():
param.requires_grad = False
def forward(self, image, no_dropout=False):
## image: b c h w
z = self.encode_with_vision_transformer(image)
return z
def encode_with_vision_transformer(self, x):
x = self.preprocess(x)
# to patches - whether to use dual patchnorm - https://arxiv.org/abs/2302.01327v1
if self.model.visual.input_patchnorm:
# einops - rearrange(x, 'b c (h p1) (w p2) -> b (h w) (c p1 p2)')
x = x.reshape(x.shape[0], x.shape[1], self.model.visual.grid_size[0], self.model.visual.patch_size[0], self.model.visual.grid_size[1], self.model.visual.patch_size[1])
x = x.permute(0, 2, 4, 1, 3, 5)
x = x.reshape(x.shape[0], self.model.visual.grid_size[0] * self.model.visual.grid_size[1], -1)
x = self.model.visual.patchnorm_pre_ln(x)
x = self.model.visual.conv1(x)
else:
x = self.model.visual.conv1(x) # shape = [*, width, grid, grid]
x = x.reshape(x.shape[0], x.shape[1], -1) # shape = [*, width, grid ** 2]
x = x.permute(0, 2, 1) # shape = [*, grid ** 2, width]
# class embeddings and positional embeddings
x = torch.cat(
[self.model.visual.class_embedding.to(x.dtype) + torch.zeros(x.shape[0], 1, x.shape[-1], dtype=x.dtype, device=x.device),
x], dim=1) # shape = [*, grid ** 2 + 1, width]
x = x + self.model.visual.positional_embedding.to(x.dtype)
# a patch_dropout of 0. would mean it is disabled and this function would do nothing but return what was passed in
x = self.model.visual.patch_dropout(x)
x = self.model.visual.ln_pre(x)
x = x.permute(1, 0, 2) # NLD -> LND
x = self.model.visual.transformer(x)
x = x.permute(1, 0, 2) # LND -> NLD
return x
class FrozenCLIPT5Encoder(AbstractEncoder):
def __init__(self, clip_version="openai/clip-vit-large-patch14", t5_version="google/t5-v1_1-xl", device="cuda",
clip_max_length=77, t5_max_length=77):
super().__init__()
self.clip_encoder = FrozenCLIPEmbedder(clip_version, device, max_length=clip_max_length)
self.t5_encoder = FrozenT5Embedder(t5_version, device, max_length=t5_max_length)
print(f"{self.clip_encoder.__class__.__name__} has {count_params(self.clip_encoder) * 1.e-6:.2f} M parameters, "
f"{self.t5_encoder.__class__.__name__} comes with {count_params(self.t5_encoder) * 1.e-6:.2f} M params.")
def encode(self, text):
return self(text)
def forward(self, text):
clip_z = self.clip_encoder.encode(text)
t5_z = self.t5_encoder.encode(text)
return [clip_z, t5_z]
# modified from https://github.com/mlfoundations/open_flamingo/blob/main/open_flamingo/src/helpers.py
# and https://github.com/lucidrains/imagen-pytorch/blob/main/imagen_pytorch/imagen_pytorch.py
# and https://github.com/tencent-ailab/IP-Adapter/blob/main/ip_adapter/resampler.py
import math
import torch
import torch.nn as nn
class ImageProjModel(nn.Module):
"""Projection Model"""
def __init__(self, cross_attention_dim=1024, clip_embeddings_dim=1024, clip_extra_context_tokens=4):
super().__init__()
self.cross_attention_dim = cross_attention_dim
self.clip_extra_context_tokens = clip_extra_context_tokens
self.proj = nn.Linear(clip_embeddings_dim, self.clip_extra_context_tokens * cross_attention_dim)
self.norm = nn.LayerNorm(cross_attention_dim)
def forward(self, image_embeds):
#embeds = image_embeds
embeds = image_embeds.type(list(self.proj.parameters())[0].dtype)
clip_extra_context_tokens = self.proj(embeds).reshape(-1, self.clip_extra_context_tokens, self.cross_attention_dim)
clip_extra_context_tokens = self.norm(clip_extra_context_tokens)
return clip_extra_context_tokens
# FFN
def FeedForward(dim, mult=4):
inner_dim = int(dim * mult)
return nn.Sequential(
nn.LayerNorm(dim),
nn.Linear(dim, inner_dim, bias=False),
nn.GELU(),
nn.Linear(inner_dim, dim, bias=False),
)
def reshape_tensor(x, heads):
bs, length, width = x.shape
#(bs, length, width) --> (bs, length, n_heads, dim_per_head)
x = x.view(bs, length, heads, -1)
# (bs, length, n_heads, dim_per_head) --> (bs, n_heads, length, dim_per_head)
x = x.transpose(1, 2)
# (bs, n_heads, length, dim_per_head) --> (bs*n_heads, length, dim_per_head)
x = x.reshape(bs, heads, length, -1)
return x
class PerceiverAttention(nn.Module):
def __init__(self, *, dim, dim_head=64, heads=8):
super().__init__()
self.scale = dim_head**-0.5
self.dim_head = dim_head
self.heads = heads
inner_dim = dim_head * heads
self.norm1 = nn.LayerNorm(dim)
self.norm2 = nn.LayerNorm(dim)
self.to_q = nn.Linear(dim, inner_dim, bias=False)
self.to_kv = nn.Linear(dim, inner_dim * 2, bias=False)
self.to_out = nn.Linear(inner_dim, dim, bias=False)
def forward(self, x, latents):
"""
Args:
x (torch.Tensor): image features
shape (b, n1, D)
latent (torch.Tensor): latent features
shape (b, n2, D)
"""
x = self.norm1(x)
latents = self.norm2(latents)
b, l, _ = latents.shape
q = self.to_q(latents)
kv_input = torch.cat((x, latents), dim=-2)
k, v = self.to_kv(kv_input).chunk(2, dim=-1)
q = reshape_tensor(q, self.heads)
k = reshape_tensor(k, self.heads)
v = reshape_tensor(v, self.heads)
# attention
scale = 1 / math.sqrt(math.sqrt(self.dim_head))
weight = (q * scale) @ (k * scale).transpose(-2, -1) # More stable with f16 than dividing afterwards
weight = torch.softmax(weight.float(), dim=-1).type(weight.dtype)
out = weight @ v
out = out.permute(0, 2, 1, 3).reshape(b, l, -1)
return self.to_out(out)
class Resampler(nn.Module):
def __init__(
self,
dim=1024,
depth=8,
dim_head=64,
heads=16,
num_queries=8,
embedding_dim=768,
output_dim=1024,
ff_mult=4,
video_length=None, # using frame-wise version or not
):
super().__init__()
## queries for a single frame / image
self.num_queries = num_queries
self.video_length = video_length
## <num_queries> queries for each frame
if video_length is not None:
num_queries = num_queries * video_length
self.latents = nn.Parameter(torch.randn(1, num_queries, dim) / dim**0.5)
self.proj_in = nn.Linear(embedding_dim, dim)
self.proj_out = nn.Linear(dim, output_dim)
self.norm_out = nn.LayerNorm(output_dim)
self.layers = nn.ModuleList([])
for _ in range(depth):
self.layers.append(
nn.ModuleList(
[
PerceiverAttention(dim=dim, dim_head=dim_head, heads=heads),
FeedForward(dim=dim, mult=ff_mult),
]
)
)
def forward(self, x):
latents = self.latents.repeat(x.size(0), 1, 1) ## B (T L) C
x = self.proj_in(x)
for attn, ff in self.layers:
latents = attn(x, latents) + latents
latents = ff(latents) + latents
latents = self.proj_out(latents)
latents = self.norm_out(latents) # B L C or B (T L) C
return latents
\ No newline at end of file
# pytorch_diffusion + derived encoder decoder
import math
import torch
import numpy as np
import torch.nn as nn
from einops import rearrange
from utils.utils import instantiate_from_config
from lvdm.modules.attention import LinearAttention
def nonlinearity(x):
# swish
return x*torch.sigmoid(x)
def Normalize(in_channels, num_groups=32):
return torch.nn.GroupNorm(num_groups=num_groups, num_channels=in_channels, eps=1e-6, affine=True)
class LinAttnBlock(LinearAttention):
"""to match AttnBlock usage"""
def __init__(self, in_channels):
super().__init__(dim=in_channels, heads=1, dim_head=in_channels)
class AttnBlock(nn.Module):
def __init__(self, in_channels):
super().__init__()
self.in_channels = in_channels
self.norm = Normalize(in_channels)
self.q = torch.nn.Conv2d(in_channels,
in_channels,
kernel_size=1,
stride=1,
padding=0)
self.k = torch.nn.Conv2d(in_channels,
in_channels,
kernel_size=1,
stride=1,
padding=0)
self.v = torch.nn.Conv2d(in_channels,
in_channels,
kernel_size=1,
stride=1,
padding=0)
self.proj_out = torch.nn.Conv2d(in_channels,
in_channels,
kernel_size=1,
stride=1,
padding=0)
def forward(self, x):
h_ = x
h_ = self.norm(h_)
q = self.q(h_)
k = self.k(h_)
v = self.v(h_)
# compute attention
b,c,h,w = q.shape
q = q.reshape(b,c,h*w) # bcl
q = q.permute(0,2,1) # bcl -> blc l=hw
k = k.reshape(b,c,h*w) # bcl
w_ = torch.bmm(q,k) # b,hw,hw w[b,i,j]=sum_c q[b,i,c]k[b,c,j]
w_ = w_ * (int(c)**(-0.5))
w_ = torch.nn.functional.softmax(w_, dim=2)
# attend to values
v = v.reshape(b,c,h*w)
w_ = w_.permute(0,2,1) # b,hw,hw (first hw of k, second of q)
h_ = torch.bmm(v,w_) # b, c,hw (hw of q) h_[b,c,j] = sum_i v[b,c,i] w_[b,i,j]
h_ = h_.reshape(b,c,h,w)
h_ = self.proj_out(h_)
return x+h_
def make_attn(in_channels, attn_type="vanilla"):
assert attn_type in ["vanilla", "linear", "none"], f'attn_type {attn_type} unknown'
#print(f"making attention of type '{attn_type}' with {in_channels} in_channels")
if attn_type == "vanilla":
return AttnBlock(in_channels)
elif attn_type == "none":
return nn.Identity(in_channels)
else:
return LinAttnBlock(in_channels)
class Downsample(nn.Module):
def __init__(self, in_channels, with_conv):
super().__init__()
self.with_conv = with_conv
self.in_channels = in_channels
if self.with_conv:
# no asymmetric padding in torch conv, must do it ourselves
self.conv = torch.nn.Conv2d(in_channels,
in_channels,
kernel_size=3,
stride=2,
padding=0)
def forward(self, x):
if self.with_conv:
pad = (0,1,0,1)
x = torch.nn.functional.pad(x, pad, mode="constant", value=0)
x = self.conv(x)
else:
x = torch.nn.functional.avg_pool2d(x, kernel_size=2, stride=2)
return x
class Upsample(nn.Module):
def __init__(self, in_channels, with_conv):
super().__init__()
self.with_conv = with_conv
self.in_channels = in_channels
if self.with_conv:
self.conv = torch.nn.Conv2d(in_channels,
in_channels,
kernel_size=3,
stride=1,
padding=1)
def forward(self, x):
x = torch.nn.functional.interpolate(x, scale_factor=2.0, mode="nearest")
if self.with_conv:
x = self.conv(x)
return x
def get_timestep_embedding(timesteps, embedding_dim):
"""
This matches the implementation in Denoising Diffusion Probabilistic Models:
From Fairseq.
Build sinusoidal embeddings.
This matches the implementation in tensor2tensor, but differs slightly
from the description in Section 3.5 of "Attention Is All You Need".
"""
assert len(timesteps.shape) == 1
half_dim = embedding_dim // 2
emb = math.log(10000) / (half_dim - 1)
emb = torch.exp(torch.arange(half_dim, dtype=torch.float32) * -emb)
emb = emb.to(device=timesteps.device)
emb = timesteps.float()[:, None] * emb[None, :]
emb = torch.cat([torch.sin(emb), torch.cos(emb)], dim=1)
if embedding_dim % 2 == 1: # zero pad
emb = torch.nn.functional.pad(emb, (0,1,0,0))
return emb
class ResnetBlock(nn.Module):
def __init__(self, *, in_channels, out_channels=None, conv_shortcut=False,
dropout, temb_channels=512):
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.use_conv_shortcut = conv_shortcut
self.norm1 = Normalize(in_channels)
self.conv1 = torch.nn.Conv2d(in_channels,
out_channels,
kernel_size=3,
stride=1,
padding=1)
if temb_channels > 0:
self.temb_proj = torch.nn.Linear(temb_channels,
out_channels)
self.norm2 = Normalize(out_channels)
self.dropout = torch.nn.Dropout(dropout)
self.conv2 = torch.nn.Conv2d(out_channels,
out_channels,
kernel_size=3,
stride=1,
padding=1)
if self.in_channels != self.out_channels:
if self.use_conv_shortcut:
self.conv_shortcut = torch.nn.Conv2d(in_channels,
out_channels,
kernel_size=3,
stride=1,
padding=1)
else:
self.nin_shortcut = torch.nn.Conv2d(in_channels,
out_channels,
kernel_size=1,
stride=1,
padding=0)
def forward(self, x, temb):
h = x
h = self.norm1(h)
h = nonlinearity(h)
h = self.conv1(h)
if temb is not None:
h = h + self.temb_proj(nonlinearity(temb))[:,:,None,None]
h = self.norm2(h)
h = nonlinearity(h)
h = self.dropout(h)
h = self.conv2(h)
if self.in_channels != self.out_channels:
if self.use_conv_shortcut:
x = self.conv_shortcut(x)
else:
x = self.nin_shortcut(x)
return x+h
class Model(nn.Module):
def __init__(self, *, ch, out_ch, ch_mult=(1,2,4,8), num_res_blocks,
attn_resolutions, dropout=0.0, resamp_with_conv=True, in_channels,
resolution, use_timestep=True, use_linear_attn=False, attn_type="vanilla"):
super().__init__()
if use_linear_attn: attn_type = "linear"
self.ch = ch
self.temb_ch = self.ch*4
self.num_resolutions = len(ch_mult)
self.num_res_blocks = num_res_blocks
self.resolution = resolution
self.in_channels = in_channels
self.use_timestep = use_timestep
if self.use_timestep:
# timestep embedding
self.temb = nn.Module()
self.temb.dense = nn.ModuleList([
torch.nn.Linear(self.ch,
self.temb_ch),
torch.nn.Linear(self.temb_ch,
self.temb_ch),
])
# downsampling
self.conv_in = torch.nn.Conv2d(in_channels,
self.ch,
kernel_size=3,
stride=1,
padding=1)
curr_res = resolution
in_ch_mult = (1,)+tuple(ch_mult)
self.down = nn.ModuleList()
for i_level in range(self.num_resolutions):
block = nn.ModuleList()
attn = nn.ModuleList()
block_in = ch*in_ch_mult[i_level]
block_out = ch*ch_mult[i_level]
for i_block in range(self.num_res_blocks):
block.append(ResnetBlock(in_channels=block_in,
out_channels=block_out,
temb_channels=self.temb_ch,
dropout=dropout))
block_in = block_out
if curr_res in attn_resolutions:
attn.append(make_attn(block_in, attn_type=attn_type))
down = nn.Module()
down.block = block
down.attn = attn
if i_level != self.num_resolutions-1:
down.downsample = Downsample(block_in, resamp_with_conv)
curr_res = curr_res // 2
self.down.append(down)
# middle
self.mid = nn.Module()
self.mid.block_1 = ResnetBlock(in_channels=block_in,
out_channels=block_in,
temb_channels=self.temb_ch,
dropout=dropout)
self.mid.attn_1 = make_attn(block_in, attn_type=attn_type)
self.mid.block_2 = ResnetBlock(in_channels=block_in,
out_channels=block_in,
temb_channels=self.temb_ch,
dropout=dropout)
# upsampling
self.up = nn.ModuleList()
for i_level in reversed(range(self.num_resolutions)):
block = nn.ModuleList()
attn = nn.ModuleList()
block_out = ch*ch_mult[i_level]
skip_in = ch*ch_mult[i_level]
for i_block in range(self.num_res_blocks+1):
if i_block == self.num_res_blocks:
skip_in = ch*in_ch_mult[i_level]
block.append(ResnetBlock(in_channels=block_in+skip_in,
out_channels=block_out,
temb_channels=self.temb_ch,
dropout=dropout))
block_in = block_out
if curr_res in attn_resolutions:
attn.append(make_attn(block_in, attn_type=attn_type))
up = nn.Module()
up.block = block
up.attn = attn
if i_level != 0:
up.upsample = Upsample(block_in, resamp_with_conv)
curr_res = curr_res * 2
self.up.insert(0, up) # prepend to get consistent order
# end
self.norm_out = Normalize(block_in)
self.conv_out = torch.nn.Conv2d(block_in,
out_ch,
kernel_size=3,
stride=1,
padding=1)
def forward(self, x, t=None, context=None):
#assert x.shape[2] == x.shape[3] == self.resolution
if context is not None:
# assume aligned context, cat along channel axis
x = torch.cat((x, context), dim=1)
if self.use_timestep:
# timestep embedding
assert t is not None
temb = get_timestep_embedding(t, self.ch)
temb = self.temb.dense[0](temb)
temb = nonlinearity(temb)
temb = self.temb.dense[1](temb)
else:
temb = None
# downsampling
hs = [self.conv_in(x)]
for i_level in range(self.num_resolutions):
for i_block in range(self.num_res_blocks):
h = self.down[i_level].block[i_block](hs[-1], temb)
if len(self.down[i_level].attn) > 0:
h = self.down[i_level].attn[i_block](h)
hs.append(h)
if i_level != self.num_resolutions-1:
hs.append(self.down[i_level].downsample(hs[-1]))
# middle
h = hs[-1]
h = self.mid.block_1(h, temb)
h = self.mid.attn_1(h)
h = self.mid.block_2(h, temb)
# upsampling
for i_level in reversed(range(self.num_resolutions)):
for i_block in range(self.num_res_blocks+1):
h = self.up[i_level].block[i_block](
torch.cat([h, hs.pop()], dim=1), temb)
if len(self.up[i_level].attn) > 0:
h = self.up[i_level].attn[i_block](h)
if i_level != 0:
h = self.up[i_level].upsample(h)
# end
h = self.norm_out(h)
h = nonlinearity(h)
h = self.conv_out(h)
return h
def get_last_layer(self):
return self.conv_out.weight
class Encoder(nn.Module):
def __init__(self, *, ch, out_ch, ch_mult=(1,2,4,8), num_res_blocks,
attn_resolutions, dropout=0.0, resamp_with_conv=True, in_channels,
resolution, z_channels, double_z=True, use_linear_attn=False, attn_type="vanilla",
**ignore_kwargs):
super().__init__()
if use_linear_attn: attn_type = "linear"
self.ch = ch
self.temb_ch = 0
self.num_resolutions = len(ch_mult)
self.num_res_blocks = num_res_blocks
self.resolution = resolution
self.in_channels = in_channels
# downsampling
self.conv_in = torch.nn.Conv2d(in_channels,
self.ch,
kernel_size=3,
stride=1,
padding=1)
curr_res = resolution
in_ch_mult = (1,)+tuple(ch_mult)
self.in_ch_mult = in_ch_mult
self.down = nn.ModuleList()
for i_level in range(self.num_resolutions):
block = nn.ModuleList()
attn = nn.ModuleList()
block_in = ch*in_ch_mult[i_level]
block_out = ch*ch_mult[i_level]
for i_block in range(self.num_res_blocks):
block.append(ResnetBlock(in_channels=block_in,
out_channels=block_out,
temb_channels=self.temb_ch,
dropout=dropout))
block_in = block_out
if curr_res in attn_resolutions:
attn.append(make_attn(block_in, attn_type=attn_type))
down = nn.Module()
down.block = block
down.attn = attn
if i_level != self.num_resolutions-1:
down.downsample = Downsample(block_in, resamp_with_conv)
curr_res = curr_res // 2
self.down.append(down)
# middle
self.mid = nn.Module()
self.mid.block_1 = ResnetBlock(in_channels=block_in,
out_channels=block_in,
temb_channels=self.temb_ch,
dropout=dropout)
self.mid.attn_1 = make_attn(block_in, attn_type=attn_type)
self.mid.block_2 = ResnetBlock(in_channels=block_in,
out_channels=block_in,
temb_channels=self.temb_ch,
dropout=dropout)
# end
self.norm_out = Normalize(block_in)
self.conv_out = torch.nn.Conv2d(block_in,
2*z_channels if double_z else z_channels,
kernel_size=3,
stride=1,
padding=1)
def forward(self, x):
# timestep embedding
temb = None
# print(f'encoder-input={x.shape}')
# downsampling
hs = [self.conv_in(x)]
# print(f'encoder-conv in feat={hs[0].shape}')
for i_level in range(self.num_resolutions):
for i_block in range(self.num_res_blocks):
h = self.down[i_level].block[i_block](hs[-1], temb)
# print(f'encoder-down feat={h.shape}')
if len(self.down[i_level].attn) > 0:
h = self.down[i_level].attn[i_block](h)
hs.append(h)
if i_level != self.num_resolutions-1:
# print(f'encoder-downsample (input)={hs[-1].shape}')
hs.append(self.down[i_level].downsample(hs[-1]))
# print(f'encoder-downsample (output)={hs[-1].shape}')
# middle
h = hs[-1]
h = self.mid.block_1(h, temb)
# print(f'encoder-mid1 feat={h.shape}')
h = self.mid.attn_1(h)
h = self.mid.block_2(h, temb)
# print(f'encoder-mid2 feat={h.shape}')
# end
h = self.norm_out(h)
h = nonlinearity(h)
h = self.conv_out(h)
# print(f'end feat={h.shape}')
return h
class Decoder(nn.Module):
def __init__(self, *, ch, out_ch, ch_mult=(1,2,4,8), num_res_blocks,
attn_resolutions, dropout=0.0, resamp_with_conv=True, in_channels,
resolution, z_channels, give_pre_end=False, tanh_out=False, use_linear_attn=False,
attn_type="vanilla", **ignorekwargs):
super().__init__()
if use_linear_attn: attn_type = "linear"
self.ch = ch
self.temb_ch = 0
self.num_resolutions = len(ch_mult)
self.num_res_blocks = num_res_blocks
self.resolution = resolution
self.in_channels = in_channels
self.give_pre_end = give_pre_end
self.tanh_out = tanh_out
# compute in_ch_mult, block_in and curr_res at lowest res
in_ch_mult = (1,)+tuple(ch_mult)
block_in = ch*ch_mult[self.num_resolutions-1]
curr_res = resolution // 2**(self.num_resolutions-1)
self.z_shape = (1,z_channels,curr_res,curr_res)
print("AE working on z of shape {} = {} dimensions.".format(
self.z_shape, np.prod(self.z_shape)))
# z to block_in
self.conv_in = torch.nn.Conv2d(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,
temb_channels=self.temb_ch,
dropout=dropout)
self.mid.attn_1 = make_attn(block_in, attn_type=attn_type)
self.mid.block_2 = ResnetBlock(in_channels=block_in,
out_channels=block_in,
temb_channels=self.temb_ch,
dropout=dropout)
# upsampling
self.up = nn.ModuleList()
for i_level in reversed(range(self.num_resolutions)):
block = nn.ModuleList()
attn = nn.ModuleList()
block_out = ch*ch_mult[i_level]
for i_block in range(self.num_res_blocks+1):
block.append(ResnetBlock(in_channels=block_in,
out_channels=block_out,
temb_channels=self.temb_ch,
dropout=dropout))
block_in = block_out
if curr_res in attn_resolutions:
attn.append(make_attn(block_in, attn_type=attn_type))
up = nn.Module()
up.block = block
up.attn = attn
if i_level != 0:
up.upsample = Upsample(block_in, resamp_with_conv)
curr_res = curr_res * 2
self.up.insert(0, up) # prepend to get consistent order
# end
self.norm_out = Normalize(block_in)
self.conv_out = torch.nn.Conv2d(block_in,
out_ch,
kernel_size=3,
stride=1,
padding=1)
def forward(self, z):
#assert z.shape[1:] == self.z_shape[1:]
self.last_z_shape = z.shape
# print(f'decoder-input={z.shape}')
# timestep embedding
temb = None
# z to block_in
h = self.conv_in(z)
# print(f'decoder-conv in feat={h.shape}')
# middle
h = self.mid.block_1(h, temb)
h = self.mid.attn_1(h)
h = self.mid.block_2(h, temb)
# print(f'decoder-mid feat={h.shape}')
# upsampling
for i_level in reversed(range(self.num_resolutions)):
for i_block in range(self.num_res_blocks+1):
h = self.up[i_level].block[i_block](h, temb)
if len(self.up[i_level].attn) > 0:
h = self.up[i_level].attn[i_block](h)
# print(f'decoder-up feat={h.shape}')
if i_level != 0:
h = self.up[i_level].upsample(h)
# print(f'decoder-upsample feat={h.shape}')
# end
if self.give_pre_end:
return h
h = self.norm_out(h)
h = nonlinearity(h)
h = self.conv_out(h)
# print(f'decoder-conv_out feat={h.shape}')
if self.tanh_out:
h = torch.tanh(h)
return h
class SimpleDecoder(nn.Module):
def __init__(self, in_channels, out_channels, *args, **kwargs):
super().__init__()
self.model = nn.ModuleList([nn.Conv2d(in_channels, in_channels, 1),
ResnetBlock(in_channels=in_channels,
out_channels=2 * in_channels,
temb_channels=0, dropout=0.0),
ResnetBlock(in_channels=2 * in_channels,
out_channels=4 * in_channels,
temb_channels=0, dropout=0.0),
ResnetBlock(in_channels=4 * in_channels,
out_channels=2 * in_channels,
temb_channels=0, dropout=0.0),
nn.Conv2d(2*in_channels, in_channels, 1),
Upsample(in_channels, with_conv=True)])
# end
self.norm_out = Normalize(in_channels)
self.conv_out = torch.nn.Conv2d(in_channels,
out_channels,
kernel_size=3,
stride=1,
padding=1)
def forward(self, x):
for i, layer in enumerate(self.model):
if i in [1,2,3]:
x = layer(x, None)
else:
x = layer(x)
h = self.norm_out(x)
h = nonlinearity(h)
x = self.conv_out(h)
return x
class UpsampleDecoder(nn.Module):
def __init__(self, in_channels, out_channels, ch, num_res_blocks, resolution,
ch_mult=(2,2), dropout=0.0):
super().__init__()
# upsampling
self.temb_ch = 0
self.num_resolutions = len(ch_mult)
self.num_res_blocks = num_res_blocks
block_in = in_channels
curr_res = resolution // 2 ** (self.num_resolutions - 1)
self.res_blocks = nn.ModuleList()
self.upsample_blocks = nn.ModuleList()
for i_level in range(self.num_resolutions):
res_block = []
block_out = ch * ch_mult[i_level]
for i_block in range(self.num_res_blocks + 1):
res_block.append(ResnetBlock(in_channels=block_in,
out_channels=block_out,
temb_channels=self.temb_ch,
dropout=dropout))
block_in = block_out
self.res_blocks.append(nn.ModuleList(res_block))
if i_level != self.num_resolutions - 1:
self.upsample_blocks.append(Upsample(block_in, True))
curr_res = curr_res * 2
# end
self.norm_out = Normalize(block_in)
self.conv_out = torch.nn.Conv2d(block_in,
out_channels,
kernel_size=3,
stride=1,
padding=1)
def forward(self, x):
# upsampling
h = x
for k, i_level in enumerate(range(self.num_resolutions)):
for i_block in range(self.num_res_blocks + 1):
h = self.res_blocks[i_level][i_block](h, None)
if i_level != self.num_resolutions - 1:
h = self.upsample_blocks[k](h)
h = self.norm_out(h)
h = nonlinearity(h)
h = self.conv_out(h)
return h
class LatentRescaler(nn.Module):
def __init__(self, factor, in_channels, mid_channels, out_channels, depth=2):
super().__init__()
# residual block, interpolate, residual block
self.factor = factor
self.conv_in = nn.Conv2d(in_channels,
mid_channels,
kernel_size=3,
stride=1,
padding=1)
self.res_block1 = nn.ModuleList([ResnetBlock(in_channels=mid_channels,
out_channels=mid_channels,
temb_channels=0,
dropout=0.0) for _ in range(depth)])
self.attn = AttnBlock(mid_channels)
self.res_block2 = nn.ModuleList([ResnetBlock(in_channels=mid_channels,
out_channels=mid_channels,
temb_channels=0,
dropout=0.0) for _ in range(depth)])
self.conv_out = nn.Conv2d(mid_channels,
out_channels,
kernel_size=1,
)
def forward(self, x):
x = self.conv_in(x)
for block in self.res_block1:
x = block(x, None)
x = torch.nn.functional.interpolate(x, size=(int(round(x.shape[2]*self.factor)), int(round(x.shape[3]*self.factor))))
x = self.attn(x)
for block in self.res_block2:
x = block(x, None)
x = self.conv_out(x)
return x
class MergedRescaleEncoder(nn.Module):
def __init__(self, in_channels, ch, resolution, out_ch, num_res_blocks,
attn_resolutions, dropout=0.0, resamp_with_conv=True,
ch_mult=(1,2,4,8), rescale_factor=1.0, rescale_module_depth=1):
super().__init__()
intermediate_chn = ch * ch_mult[-1]
self.encoder = Encoder(in_channels=in_channels, num_res_blocks=num_res_blocks, ch=ch, ch_mult=ch_mult,
z_channels=intermediate_chn, double_z=False, resolution=resolution,
attn_resolutions=attn_resolutions, dropout=dropout, resamp_with_conv=resamp_with_conv,
out_ch=None)
self.rescaler = LatentRescaler(factor=rescale_factor, in_channels=intermediate_chn,
mid_channels=intermediate_chn, out_channels=out_ch, depth=rescale_module_depth)
def forward(self, x):
x = self.encoder(x)
x = self.rescaler(x)
return x
class MergedRescaleDecoder(nn.Module):
def __init__(self, z_channels, out_ch, resolution, num_res_blocks, attn_resolutions, ch, ch_mult=(1,2,4,8),
dropout=0.0, resamp_with_conv=True, rescale_factor=1.0, rescale_module_depth=1):
super().__init__()
tmp_chn = z_channels*ch_mult[-1]
self.decoder = Decoder(out_ch=out_ch, z_channels=tmp_chn, attn_resolutions=attn_resolutions, dropout=dropout,
resamp_with_conv=resamp_with_conv, in_channels=None, num_res_blocks=num_res_blocks,
ch_mult=ch_mult, resolution=resolution, ch=ch)
self.rescaler = LatentRescaler(factor=rescale_factor, in_channels=z_channels, mid_channels=tmp_chn,
out_channels=tmp_chn, depth=rescale_module_depth)
def forward(self, x):
x = self.rescaler(x)
x = self.decoder(x)
return x
class Upsampler(nn.Module):
def __init__(self, in_size, out_size, in_channels, out_channels, ch_mult=2):
super().__init__()
assert out_size >= in_size
num_blocks = int(np.log2(out_size//in_size))+1
factor_up = 1.+ (out_size % in_size)
print(f"Building {self.__class__.__name__} with in_size: {in_size} --> out_size {out_size} and factor {factor_up}")
self.rescaler = LatentRescaler(factor=factor_up, in_channels=in_channels, mid_channels=2*in_channels,
out_channels=in_channels)
self.decoder = Decoder(out_ch=out_channels, resolution=out_size, z_channels=in_channels, num_res_blocks=2,
attn_resolutions=[], in_channels=None, ch=in_channels,
ch_mult=[ch_mult for _ in range(num_blocks)])
def forward(self, x):
x = self.rescaler(x)
x = self.decoder(x)
return x
class Resize(nn.Module):
def __init__(self, in_channels=None, learned=False, mode="bilinear"):
super().__init__()
self.with_conv = learned
self.mode = mode
if self.with_conv:
print(f"Note: {self.__class__.__name} uses learned downsampling and will ignore the fixed {mode} mode")
raise NotImplementedError()
assert in_channels is not None
# no asymmetric padding in torch conv, must do it ourselves
self.conv = torch.nn.Conv2d(in_channels,
in_channels,
kernel_size=4,
stride=2,
padding=1)
def forward(self, x, scale_factor=1.0):
if scale_factor==1.0:
return x
else:
x = torch.nn.functional.interpolate(x, mode=self.mode, align_corners=False, scale_factor=scale_factor)
return x
class FirstStagePostProcessor(nn.Module):
def __init__(self, ch_mult:list, in_channels,
pretrained_model:nn.Module=None,
reshape=False,
n_channels=None,
dropout=0.,
pretrained_config=None):
super().__init__()
if pretrained_config is None:
assert pretrained_model is not None, 'Either "pretrained_model" or "pretrained_config" must not be None'
self.pretrained_model = pretrained_model
else:
assert pretrained_config is not None, 'Either "pretrained_model" or "pretrained_config" must not be None'
self.instantiate_pretrained(pretrained_config)
self.do_reshape = reshape
if n_channels is None:
n_channels = self.pretrained_model.encoder.ch
self.proj_norm = Normalize(in_channels,num_groups=in_channels//2)
self.proj = nn.Conv2d(in_channels,n_channels,kernel_size=3,
stride=1,padding=1)
blocks = []
downs = []
ch_in = n_channels
for m in ch_mult:
blocks.append(ResnetBlock(in_channels=ch_in,out_channels=m*n_channels,dropout=dropout))
ch_in = m * n_channels
downs.append(Downsample(ch_in, with_conv=False))
self.model = nn.ModuleList(blocks)
self.downsampler = nn.ModuleList(downs)
def instantiate_pretrained(self, config):
model = instantiate_from_config(config)
self.pretrained_model = model.eval()
# self.pretrained_model.train = False
for param in self.pretrained_model.parameters():
param.requires_grad = False
@torch.no_grad()
def encode_with_pretrained(self,x):
c = self.pretrained_model.encode(x)
if isinstance(c, DiagonalGaussianDistribution):
c = c.mode()
return c
def forward(self,x):
z_fs = self.encode_with_pretrained(x)
z = self.proj_norm(z_fs)
z = self.proj(z)
z = nonlinearity(z)
for submodel, downmodel in zip(self.model,self.downsampler):
z = submodel(z,temb=None)
z = downmodel(z)
if self.do_reshape:
z = rearrange(z,'b c h w -> b (h w) c')
return z
\ No newline at end of file
from functools import partial
from abc import abstractmethod
import torch
import torch.nn as nn
from einops import rearrange
import torch.nn.functional as F
from lvdm.models.utils_diffusion import timestep_embedding
from lvdm.common import checkpoint
from lvdm.basics import (
zero_module,
conv_nd,
linear,
avg_pool_nd,
normalization
)
from lvdm.modules.attention import SpatialTransformer, TemporalTransformer
class TimestepBlock(nn.Module):
"""
Any module where forward() takes timestep embeddings as a second argument.
"""
@abstractmethod
def forward(self, x, emb):
"""
Apply the module to `x` given `emb` timestep embeddings.
"""
class TimestepEmbedSequential(nn.Sequential, TimestepBlock):
"""
A sequential module that passes timestep embeddings to the children that
support it as an extra input.
"""
def forward(self, x, emb, context=None, batch_size=None):
for layer in self:
if isinstance(layer, TimestepBlock):
x = layer(x, emb, batch_size=batch_size)
elif isinstance(layer, SpatialTransformer):
x = layer(x, context)
elif isinstance(layer, TemporalTransformer):
x = rearrange(x, '(b f) c h w -> b c f h w', b=batch_size)
x = layer(x, context)
x = rearrange(x, 'b c f h w -> (b f) c h w')
else:
x = layer(x)
return x
class Downsample(nn.Module):
"""
A downsampling layer with an optional convolution.
:param channels: channels in the inputs and outputs.
:param use_conv: a bool determining if a convolution is applied.
:param dims: determines if the signal is 1D, 2D, or 3D. If 3D, then
downsampling occurs in the inner-two dimensions.
"""
def __init__(self, channels, use_conv, dims=2, out_channels=None, padding=1):
super().__init__()
self.channels = channels
self.out_channels = out_channels or channels
self.use_conv = use_conv
self.dims = dims
stride = 2 if dims != 3 else (1, 2, 2)
if use_conv:
self.op = conv_nd(
dims, self.channels, self.out_channels, 3, stride=stride, padding=padding
)
else:
assert self.channels == self.out_channels
self.op = avg_pool_nd(dims, kernel_size=stride, stride=stride)
def forward(self, x):
assert x.shape[1] == self.channels
return self.op(x)
class Upsample(nn.Module):
"""
An upsampling layer with an optional convolution.
:param channels: channels in the inputs and outputs.
:param use_conv: a bool determining if a convolution is applied.
:param dims: determines if the signal is 1D, 2D, or 3D. If 3D, then
upsampling occurs in the inner-two dimensions.
"""
def __init__(self, channels, use_conv, dims=2, out_channels=None, padding=1):
super().__init__()
self.channels = channels
self.out_channels = out_channels or channels
self.use_conv = use_conv
self.dims = dims
if use_conv:
self.conv = conv_nd(dims, self.channels, self.out_channels, 3, padding=padding)
def forward(self, x):
assert x.shape[1] == self.channels
if self.dims == 3:
x = F.interpolate(x, (x.shape[2], x.shape[3] * 2, x.shape[4] * 2), mode='nearest')
else:
x = F.interpolate(x, scale_factor=2, mode='nearest')
if self.use_conv:
x = self.conv(x)
return x
class ResBlock(TimestepBlock):
"""
A residual block that can optionally change the number of channels.
:param channels: the number of input channels.
:param emb_channels: the number of timestep embedding channels.
:param dropout: the rate of dropout.
:param out_channels: if specified, the number of out channels.
:param use_conv: if True and out_channels is specified, use a spatial
convolution instead of a smaller 1x1 convolution to change the
channels in the skip connection.
:param dims: determines if the signal is 1D, 2D, or 3D.
:param up: if True, use this block for upsampling.
:param down: if True, use this block for downsampling.
:param use_temporal_conv: if True, use the temporal convolution.
:param use_image_dataset: if True, the temporal parameters will not be optimized.
"""
def __init__(
self,
channels,
emb_channels,
dropout,
out_channels=None,
use_scale_shift_norm=False,
dims=2,
use_checkpoint=False,
use_conv=False,
up=False,
down=False,
use_temporal_conv=False,
tempspatial_aware=False
):
super().__init__()
self.channels = channels
self.emb_channels = emb_channels
self.dropout = dropout
self.out_channels = out_channels or channels
self.use_conv = use_conv
self.use_checkpoint = use_checkpoint
self.use_scale_shift_norm = use_scale_shift_norm
self.use_temporal_conv = use_temporal_conv
self.in_layers = nn.Sequential(
normalization(channels),
nn.SiLU(),
conv_nd(dims, channels, self.out_channels, 3, padding=1),
)
self.updown = up or down
if up:
self.h_upd = Upsample(channels, False, dims)
self.x_upd = Upsample(channels, False, dims)
elif down:
self.h_upd = Downsample(channels, False, dims)
self.x_upd = Downsample(channels, False, dims)
else:
self.h_upd = self.x_upd = nn.Identity()
self.emb_layers = nn.Sequential(
nn.SiLU(),
nn.Linear(
emb_channels,
2 * self.out_channels if use_scale_shift_norm else self.out_channels,
),
)
self.out_layers = nn.Sequential(
normalization(self.out_channels),
nn.SiLU(),
nn.Dropout(p=dropout),
zero_module(nn.Conv2d(self.out_channels, self.out_channels, 3, padding=1)),
)
if self.out_channels == channels:
self.skip_connection = nn.Identity()
elif use_conv:
self.skip_connection = conv_nd(dims, channels, self.out_channels, 3, padding=1)
else:
self.skip_connection = conv_nd(dims, channels, self.out_channels, 1)
if self.use_temporal_conv:
self.temopral_conv = TemporalConvBlock(
self.out_channels,
self.out_channels,
dropout=0.1,
spatial_aware=tempspatial_aware
)
def forward(self, x, emb, batch_size=None):
"""
Apply the block to a Tensor, conditioned on a timestep embedding.
:param x: an [N x C x ...] Tensor of features.
:param emb: an [N x emb_channels] Tensor of timestep embeddings.
:return: an [N x C x ...] Tensor of outputs.
"""
input_tuple = (x, emb)
if batch_size:
forward_batchsize = partial(self._forward, batch_size=batch_size)
return checkpoint(forward_batchsize, input_tuple, self.parameters(), self.use_checkpoint)
return checkpoint(self._forward, input_tuple, self.parameters(), self.use_checkpoint)
def _forward(self, x, emb, batch_size=None):
if self.updown:
in_rest, in_conv = self.in_layers[:-1], self.in_layers[-1]
h = in_rest(x)
h = self.h_upd(h)
x = self.x_upd(x)
h = in_conv(h)
else:
h = self.in_layers(x)
emb_out = self.emb_layers(emb).type(h.dtype)
while len(emb_out.shape) < len(h.shape):
emb_out = emb_out[..., None]
if self.use_scale_shift_norm:
out_norm, out_rest = self.out_layers[0], self.out_layers[1:]
scale, shift = torch.chunk(emb_out, 2, dim=1)
h = out_norm(h) * (1 + scale) + shift
h = out_rest(h)
else:
h = h + emb_out
h = self.out_layers(h)
h = self.skip_connection(x) + h
if self.use_temporal_conv and batch_size:
h = rearrange(h, '(b t) c h w -> b c t h w', b=batch_size)
h = self.temopral_conv(h)
h = rearrange(h, 'b c t h w -> (b t) c h w')
return h
class TemporalConvBlock(nn.Module):
"""
Adapted from modelscope: https://github.com/modelscope/modelscope/blob/master/modelscope/models/multi_modal/video_synthesis/unet_sd.py
"""
def __init__(self, in_channels, out_channels=None, dropout=0.0, spatial_aware=False):
super(TemporalConvBlock, self).__init__()
if out_channels is None:
out_channels = in_channels
self.in_channels = in_channels
self.out_channels = out_channels
th_kernel_shape = (3, 1, 1) if not spatial_aware else (3, 3, 1)
th_padding_shape = (1, 0, 0) if not spatial_aware else (1, 1, 0)
tw_kernel_shape = (3, 1, 1) if not spatial_aware else (3, 1, 3)
tw_padding_shape = (1, 0, 0) if not spatial_aware else (1, 0, 1)
# conv layers
self.conv1 = nn.Sequential(
nn.GroupNorm(32, in_channels), nn.SiLU(),
nn.Conv3d(in_channels, out_channels, th_kernel_shape, padding=th_padding_shape))
self.conv2 = nn.Sequential(
nn.GroupNorm(32, out_channels), nn.SiLU(), nn.Dropout(dropout),
nn.Conv3d(out_channels, in_channels, tw_kernel_shape, padding=tw_padding_shape))
self.conv3 = nn.Sequential(
nn.GroupNorm(32, out_channels), nn.SiLU(), nn.Dropout(dropout),
nn.Conv3d(out_channels, in_channels, th_kernel_shape, padding=th_padding_shape))
self.conv4 = nn.Sequential(
nn.GroupNorm(32, out_channels), nn.SiLU(), nn.Dropout(dropout),
nn.Conv3d(out_channels, in_channels, tw_kernel_shape, padding=tw_padding_shape))
# zero out the last layer params,so the conv block is identity
nn.init.zeros_(self.conv4[-1].weight)
nn.init.zeros_(self.conv4[-1].bias)
def forward(self, x):
identity = x
x = self.conv1(x)
x = self.conv2(x)
x = self.conv3(x)
x = self.conv4(x)
return identity + x
class UNetModel(nn.Module):
"""
The full UNet model with attention and timestep embedding.
:param in_channels: in_channels in the input Tensor.
:param model_channels: base channel count for the model.
:param out_channels: channels in the output Tensor.
:param num_res_blocks: number of residual blocks per downsample.
:param attention_resolutions: a collection of downsample rates at which
attention will take place. May be a set, list, or tuple.
For example, if this contains 4, then at 4x downsampling, attention
will be used.
:param dropout: the dropout probability.
:param channel_mult: channel multiplier for each level of the UNet.
:param conv_resample: if True, use learned convolutions for upsampling and
downsampling.
:param dims: determines if the signal is 1D, 2D, or 3D.
:param num_classes: if specified (as an int), then this model will be
class-conditional with `num_classes` classes.
:param use_checkpoint: use gradient checkpointing to reduce memory usage.
:param num_heads: the number of attention heads in each attention layer.
:param num_heads_channels: if specified, ignore num_heads and instead use
a fixed channel width per attention head.
:param num_heads_upsample: works with num_heads to set a different number
of heads for upsampling. Deprecated.
:param use_scale_shift_norm: use a FiLM-like conditioning mechanism.
:param resblock_updown: use residual blocks for up/downsampling.
:param use_new_attention_order: use a different attention pattern for potentially
increased efficiency.
"""
def __init__(self,
in_channels,
model_channels,
out_channels,
num_res_blocks,
attention_resolutions,
dropout=0.0,
channel_mult=(1, 2, 4, 8),
conv_resample=True,
dims=2,
context_dim=None,
use_scale_shift_norm=False,
resblock_updown=False,
num_heads=-1,
num_head_channels=-1,
transformer_depth=1,
use_linear=False,
use_checkpoint=False,
temporal_conv=False,
tempspatial_aware=False,
temporal_attention=True,
use_relative_position=True,
use_causal_attention=False,
temporal_length=None,
use_fp16=False,
addition_attention=False,
temporal_selfatt_only=True,
image_cross_attention=False,
image_cross_attention_scale_learnable=False,
default_fs=4,
fs_condition=False,
):
super(UNetModel, self).__init__()
if num_heads == -1:
assert num_head_channels != -1, 'Either num_heads or num_head_channels has to be set'
if num_head_channels == -1:
assert num_heads != -1, 'Either num_heads or num_head_channels has to be set'
self.in_channels = in_channels
self.model_channels = model_channels
self.out_channels = out_channels
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.temporal_attention = temporal_attention
time_embed_dim = model_channels * 4
self.use_checkpoint = use_checkpoint
self.dtype = torch.float16 if use_fp16 else torch.float32
temporal_self_att_only = True
self.addition_attention = addition_attention
self.temporal_length = temporal_length
self.image_cross_attention = image_cross_attention
self.image_cross_attention_scale_learnable = image_cross_attention_scale_learnable
self.default_fs = default_fs
self.fs_condition = fs_condition
## Time embedding blocks
self.time_embed = nn.Sequential(
linear(model_channels, time_embed_dim),
nn.SiLU(),
linear(time_embed_dim, time_embed_dim),
)
if fs_condition:
self.fps_embedding = nn.Sequential(
linear(model_channels, time_embed_dim),
nn.SiLU(),
linear(time_embed_dim, time_embed_dim),
)
nn.init.zeros_(self.fps_embedding[-1].weight)
nn.init.zeros_(self.fps_embedding[-1].bias)
## Input Block
self.input_blocks = nn.ModuleList(
[
TimestepEmbedSequential(conv_nd(dims, in_channels, model_channels, 3, padding=1))
]
)
if self.addition_attention:
self.init_attn=TimestepEmbedSequential(
TemporalTransformer(
model_channels,
n_heads=8,
d_head=num_head_channels,
depth=transformer_depth,
context_dim=context_dim,
use_checkpoint=use_checkpoint, only_self_att=temporal_selfatt_only,
causal_attention=False, relative_position=use_relative_position,
temporal_length=temporal_length))
input_block_chans = [model_channels]
ch = model_channels
ds = 1
for level, mult in enumerate(channel_mult):
for _ in range(num_res_blocks):
layers = [
ResBlock(ch, time_embed_dim, dropout,
out_channels=mult * model_channels, dims=dims, use_checkpoint=use_checkpoint,
use_scale_shift_norm=use_scale_shift_norm, tempspatial_aware=tempspatial_aware,
use_temporal_conv=temporal_conv
)
]
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(
SpatialTransformer(ch, num_heads, dim_head,
depth=transformer_depth, context_dim=context_dim, use_linear=use_linear,
use_checkpoint=use_checkpoint, disable_self_attn=False,
video_length=temporal_length, image_cross_attention=self.image_cross_attention,
image_cross_attention_scale_learnable=self.image_cross_attention_scale_learnable,
)
)
if self.temporal_attention:
layers.append(
TemporalTransformer(ch, num_heads, dim_head,
depth=transformer_depth, context_dim=context_dim, use_linear=use_linear,
use_checkpoint=use_checkpoint, only_self_att=temporal_self_att_only,
causal_attention=use_causal_attention, relative_position=use_relative_position,
temporal_length=temporal_length
)
)
self.input_blocks.append(TimestepEmbedSequential(*layers))
input_block_chans.append(ch)
if level != len(channel_mult) - 1:
out_ch = ch
self.input_blocks.append(
TimestepEmbedSequential(
ResBlock(ch, time_embed_dim, dropout,
out_channels=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)
)
)
ch = out_ch
input_block_chans.append(ch)
ds *= 2
if num_head_channels == -1:
dim_head = ch // num_heads
else:
num_heads = ch // num_head_channels
dim_head = num_head_channels
layers = [
ResBlock(ch, time_embed_dim, dropout,
dims=dims, use_checkpoint=use_checkpoint,
use_scale_shift_norm=use_scale_shift_norm, tempspatial_aware=tempspatial_aware,
use_temporal_conv=temporal_conv
),
SpatialTransformer(ch, num_heads, dim_head,
depth=transformer_depth, context_dim=context_dim, use_linear=use_linear,
use_checkpoint=use_checkpoint, disable_self_attn=False, video_length=temporal_length,
image_cross_attention=self.image_cross_attention,image_cross_attention_scale_learnable=self.image_cross_attention_scale_learnable
)
]
if self.temporal_attention:
layers.append(
TemporalTransformer(ch, num_heads, dim_head,
depth=transformer_depth, context_dim=context_dim, use_linear=use_linear,
use_checkpoint=use_checkpoint, only_self_att=temporal_self_att_only,
causal_attention=use_causal_attention, relative_position=use_relative_position,
temporal_length=temporal_length
)
)
layers.append(
ResBlock(ch, time_embed_dim, dropout,
dims=dims, use_checkpoint=use_checkpoint,
use_scale_shift_norm=use_scale_shift_norm, tempspatial_aware=tempspatial_aware,
use_temporal_conv=temporal_conv
)
)
## Middle Block
self.middle_block = TimestepEmbedSequential(*layers)
## Output Block
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 = [
ResBlock(ch + ich, time_embed_dim, dropout,
out_channels=mult * model_channels, dims=dims, use_checkpoint=use_checkpoint,
use_scale_shift_norm=use_scale_shift_norm, tempspatial_aware=tempspatial_aware,
use_temporal_conv=temporal_conv
)
]
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(
SpatialTransformer(ch, num_heads, dim_head,
depth=transformer_depth, context_dim=context_dim, use_linear=use_linear,
use_checkpoint=use_checkpoint, disable_self_attn=False, video_length=temporal_length,
image_cross_attention=self.image_cross_attention,image_cross_attention_scale_learnable=self.image_cross_attention_scale_learnable
)
)
if self.temporal_attention:
layers.append(
TemporalTransformer(ch, num_heads, dim_head,
depth=transformer_depth, context_dim=context_dim, use_linear=use_linear,
use_checkpoint=use_checkpoint, only_self_att=temporal_self_att_only,
causal_attention=use_causal_attention, relative_position=use_relative_position,
temporal_length=temporal_length
)
)
if level and i == num_res_blocks:
out_ch = ch
layers.append(
ResBlock(ch, time_embed_dim, dropout,
out_channels=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)
)
ds //= 2
self.output_blocks.append(TimestepEmbedSequential(*layers))
self.out = nn.Sequential(
normalization(ch),
nn.SiLU(),
zero_module(conv_nd(dims, model_channels, out_channels, 3, padding=1)),
)
def forward(self, x, timesteps, context=None, features_adapter=None, fs=None, **kwargs):
b,_,t,_,_ = x.shape
t_emb = timestep_embedding(timesteps, self.model_channels, repeat_only=False).type(x.dtype)
emb = self.time_embed(t_emb)
## repeat t times for context [(b t) 77 768] & time embedding
## check if we use per-frame image conditioning
_, l_context, _ = context.shape
if l_context == 77 + t*16: ## !!! HARD CODE here
context_text, context_img = context[:,:77,:], context[:,77:,:]
context_text = context_text.repeat_interleave(repeats=t, dim=0)
context_img = rearrange(context_img, 'b (t l) c -> (b t) l c', t=t)
context = torch.cat([context_text, context_img], dim=1)
else:
context = context.repeat_interleave(repeats=t, dim=0)
emb = emb.repeat_interleave(repeats=t, dim=0)
## always in shape (b t) c h w, except for temporal layer
x = rearrange(x, 'b c t h w -> (b t) c h w')
## combine emb
if self.fs_condition:
if fs is None:
fs = torch.tensor(
[self.default_fs] * b, dtype=torch.long, device=x.device)
fs_emb = timestep_embedding(fs, self.model_channels, repeat_only=False).type(x.dtype)
fs_embed = self.fps_embedding(fs_emb)
fs_embed = fs_embed.repeat_interleave(repeats=t, dim=0)
emb = emb + fs_embed
h = x.type(self.dtype)
adapter_idx = 0
hs = []
for id, module in enumerate(self.input_blocks):
h = module(h, emb, context=context, batch_size=b)
if id ==0 and self.addition_attention:
h = self.init_attn(h, emb, context=context, batch_size=b)
## plug-in adapter features
if ((id+1)%3 == 0) and features_adapter is not None:
h = h + features_adapter[adapter_idx]
adapter_idx += 1
hs.append(h)
if features_adapter is not None:
assert len(features_adapter)==adapter_idx, 'Wrong features_adapter'
h = self.middle_block(h, emb, context=context, batch_size=b)
for module in self.output_blocks:
h = torch.cat([h, hs.pop()], dim=1)
h = module(h, emb, context=context, batch_size=b)
h = h.type(x.dtype)
y = self.out(h)
# reshape back to (b c t h w)
y = rearrange(y, '(b t) c h w -> b c t h w', b=b)
return y
\ No newline at end of file
"""shout-out to https://github.com/lucidrains/x-transformers/tree/main/x_transformers"""
from functools import partial
from inspect import isfunction
from collections import namedtuple
from einops import rearrange, repeat
import torch
from torch import nn, einsum
import torch.nn.functional as F
# constants
DEFAULT_DIM_HEAD = 64
Intermediates = namedtuple('Intermediates', [
'pre_softmax_attn',
'post_softmax_attn'
])
LayerIntermediates = namedtuple('Intermediates', [
'hiddens',
'attn_intermediates'
])
class AbsolutePositionalEmbedding(nn.Module):
def __init__(self, dim, max_seq_len):
super().__init__()
self.emb = nn.Embedding(max_seq_len, dim)
self.init_()
def init_(self):
nn.init.normal_(self.emb.weight, std=0.02)
def forward(self, x):
n = torch.arange(x.shape[1], device=x.device)
return self.emb(n)[None, :, :]
class FixedPositionalEmbedding(nn.Module):
def __init__(self, dim):
super().__init__()
inv_freq = 1. / (10000 ** (torch.arange(0, dim, 2).float() / dim))
self.register_buffer('inv_freq', inv_freq)
def forward(self, x, seq_dim=1, offset=0):
t = torch.arange(x.shape[seq_dim], device=x.device).type_as(self.inv_freq) + offset
sinusoid_inp = torch.einsum('i , j -> i j', t, self.inv_freq)
emb = torch.cat((sinusoid_inp.sin(), sinusoid_inp.cos()), dim=-1)
return emb[None, :, :]
# helpers
def exists(val):
return val is not None
def default(val, d):
if exists(val):
return val
return d() if isfunction(d) else d
def always(val):
def inner(*args, **kwargs):
return val
return inner
def not_equals(val):
def inner(x):
return x != val
return inner
def equals(val):
def inner(x):
return x == val
return inner
def max_neg_value(tensor):
return -torch.finfo(tensor.dtype).max
# keyword argument helpers
def pick_and_pop(keys, d):
values = list(map(lambda key: d.pop(key), keys))
return dict(zip(keys, values))
def group_dict_by_key(cond, d):
return_val = [dict(), dict()]
for key in d.keys():
match = bool(cond(key))
ind = int(not match)
return_val[ind][key] = d[key]
return (*return_val,)
def string_begins_with(prefix, str):
return str.startswith(prefix)
def group_by_key_prefix(prefix, d):
return group_dict_by_key(partial(string_begins_with, prefix), d)
def groupby_prefix_and_trim(prefix, d):
kwargs_with_prefix, kwargs = group_dict_by_key(partial(string_begins_with, prefix), d)
kwargs_without_prefix = dict(map(lambda x: (x[0][len(prefix):], x[1]), tuple(kwargs_with_prefix.items())))
return kwargs_without_prefix, kwargs
# classes
class Scale(nn.Module):
def __init__(self, value, fn):
super().__init__()
self.value = value
self.fn = fn
def forward(self, x, **kwargs):
x, *rest = self.fn(x, **kwargs)
return (x * self.value, *rest)
class Rezero(nn.Module):
def __init__(self, fn):
super().__init__()
self.fn = fn
self.g = nn.Parameter(torch.zeros(1))
def forward(self, x, **kwargs):
x, *rest = self.fn(x, **kwargs)
return (x * self.g, *rest)
class ScaleNorm(nn.Module):
def __init__(self, dim, eps=1e-5):
super().__init__()
self.scale = dim ** -0.5
self.eps = eps
self.g = nn.Parameter(torch.ones(1))
def forward(self, x):
norm = torch.norm(x, dim=-1, keepdim=True) * self.scale
return x / norm.clamp(min=self.eps) * self.g
class RMSNorm(nn.Module):
def __init__(self, dim, eps=1e-8):
super().__init__()
self.scale = dim ** -0.5
self.eps = eps
self.g = nn.Parameter(torch.ones(dim))
def forward(self, x):
norm = torch.norm(x, dim=-1, keepdim=True) * self.scale
return x / norm.clamp(min=self.eps) * self.g
class Residual(nn.Module):
def forward(self, x, residual):
return x + residual
class GRUGating(nn.Module):
def __init__(self, dim):
super().__init__()
self.gru = nn.GRUCell(dim, dim)
def forward(self, x, residual):
gated_output = self.gru(
rearrange(x, 'b n d -> (b n) d'),
rearrange(residual, 'b n d -> (b n) d')
)
return gated_output.reshape_as(x)
# feedforward
class GEGLU(nn.Module):
def __init__(self, dim_in, dim_out):
super().__init__()
self.proj = nn.Linear(dim_in, dim_out * 2)
def forward(self, x):
x, gate = self.proj(x).chunk(2, dim=-1)
return x * F.gelu(gate)
class FeedForward(nn.Module):
def __init__(self, dim, dim_out=None, mult=4, glu=False, dropout=0.):
super().__init__()
inner_dim = int(dim * mult)
dim_out = default(dim_out, dim)
project_in = nn.Sequential(
nn.Linear(dim, inner_dim),
nn.GELU()
) if not glu else GEGLU(dim, inner_dim)
self.net = nn.Sequential(
project_in,
nn.Dropout(dropout),
nn.Linear(inner_dim, dim_out)
)
def forward(self, x):
return self.net(x)
# attention.
class Attention(nn.Module):
def __init__(
self,
dim,
dim_head=DEFAULT_DIM_HEAD,
heads=8,
causal=False,
mask=None,
talking_heads=False,
sparse_topk=None,
use_entmax15=False,
num_mem_kv=0,
dropout=0.,
on_attn=False
):
super().__init__()
if use_entmax15:
raise NotImplementedError("Check out entmax activation instead of softmax activation!")
self.scale = dim_head ** -0.5
self.heads = heads
self.causal = causal
self.mask = mask
inner_dim = dim_head * heads
self.to_q = nn.Linear(dim, inner_dim, bias=False)
self.to_k = nn.Linear(dim, inner_dim, bias=False)
self.to_v = nn.Linear(dim, inner_dim, bias=False)
self.dropout = nn.Dropout(dropout)
# talking heads
self.talking_heads = talking_heads
if talking_heads:
self.pre_softmax_proj = nn.Parameter(torch.randn(heads, heads))
self.post_softmax_proj = nn.Parameter(torch.randn(heads, heads))
# explicit topk sparse attention
self.sparse_topk = sparse_topk
# entmax
#self.attn_fn = entmax15 if use_entmax15 else F.softmax
self.attn_fn = F.softmax
# add memory key / values
self.num_mem_kv = num_mem_kv
if num_mem_kv > 0:
self.mem_k = nn.Parameter(torch.randn(heads, num_mem_kv, dim_head))
self.mem_v = nn.Parameter(torch.randn(heads, num_mem_kv, dim_head))
# attention on attention
self.attn_on_attn = on_attn
self.to_out = nn.Sequential(nn.Linear(inner_dim, dim * 2), nn.GLU()) if on_attn else nn.Linear(inner_dim, dim)
def forward(
self,
x,
context=None,
mask=None,
context_mask=None,
rel_pos=None,
sinusoidal_emb=None,
prev_attn=None,
mem=None
):
b, n, _, h, talking_heads, device = *x.shape, self.heads, self.talking_heads, x.device
kv_input = default(context, x)
q_input = x
k_input = kv_input
v_input = kv_input
if exists(mem):
k_input = torch.cat((mem, k_input), dim=-2)
v_input = torch.cat((mem, v_input), dim=-2)
if exists(sinusoidal_emb):
# in shortformer, the query would start at a position offset depending on the past cached memory
offset = k_input.shape[-2] - q_input.shape[-2]
q_input = q_input + sinusoidal_emb(q_input, offset=offset)
k_input = k_input + sinusoidal_emb(k_input)
q = self.to_q(q_input)
k = self.to_k(k_input)
v = self.to_v(v_input)
q, k, v = map(lambda t: rearrange(t, 'b n (h d) -> b h n d', h=h), (q, k, v))
input_mask = None
if any(map(exists, (mask, context_mask))):
q_mask = default(mask, lambda: torch.ones((b, n), device=device).bool())
k_mask = q_mask if not exists(context) else context_mask
k_mask = default(k_mask, lambda: torch.ones((b, k.shape[-2]), device=device).bool())
q_mask = rearrange(q_mask, 'b i -> b () i ()')
k_mask = rearrange(k_mask, 'b j -> b () () j')
input_mask = q_mask * k_mask
if self.num_mem_kv > 0:
mem_k, mem_v = map(lambda t: repeat(t, 'h n d -> b h n d', b=b), (self.mem_k, self.mem_v))
k = torch.cat((mem_k, k), dim=-2)
v = torch.cat((mem_v, v), dim=-2)
if exists(input_mask):
input_mask = F.pad(input_mask, (self.num_mem_kv, 0), value=True)
dots = einsum('b h i d, b h j d -> b h i j', q, k) * self.scale
mask_value = max_neg_value(dots)
if exists(prev_attn):
dots = dots + prev_attn
pre_softmax_attn = dots
if talking_heads:
dots = einsum('b h i j, h k -> b k i j', dots, self.pre_softmax_proj).contiguous()
if exists(rel_pos):
dots = rel_pos(dots)
if exists(input_mask):
dots.masked_fill_(~input_mask, mask_value)
del input_mask
if self.causal:
i, j = dots.shape[-2:]
r = torch.arange(i, device=device)
mask = rearrange(r, 'i -> () () i ()') < rearrange(r, 'j -> () () () j')
mask = F.pad(mask, (j - i, 0), value=False)
dots.masked_fill_(mask, mask_value)
del mask
if exists(self.sparse_topk) and self.sparse_topk < dots.shape[-1]:
top, _ = dots.topk(self.sparse_topk, dim=-1)
vk = top[..., -1].unsqueeze(-1).expand_as(dots)
mask = dots < vk
dots.masked_fill_(mask, mask_value)
del mask
attn = self.attn_fn(dots, dim=-1)
post_softmax_attn = attn
attn = self.dropout(attn)
if talking_heads:
attn = einsum('b h i j, h k -> b k i j', attn, self.post_softmax_proj).contiguous()
out = einsum('b h i j, b h j d -> b h i d', attn, v)
out = rearrange(out, 'b h n d -> b n (h d)')
intermediates = Intermediates(
pre_softmax_attn=pre_softmax_attn,
post_softmax_attn=post_softmax_attn
)
return self.to_out(out), intermediates
class AttentionLayers(nn.Module):
def __init__(
self,
dim,
depth,
heads=8,
causal=False,
cross_attend=False,
only_cross=False,
use_scalenorm=False,
use_rmsnorm=False,
use_rezero=False,
rel_pos_num_buckets=32,
rel_pos_max_distance=128,
position_infused_attn=False,
custom_layers=None,
sandwich_coef=None,
par_ratio=None,
residual_attn=False,
cross_residual_attn=False,
macaron=False,
pre_norm=True,
gate_residual=False,
**kwargs
):
super().__init__()
ff_kwargs, kwargs = groupby_prefix_and_trim('ff_', kwargs)
attn_kwargs, _ = groupby_prefix_and_trim('attn_', kwargs)
dim_head = attn_kwargs.get('dim_head', DEFAULT_DIM_HEAD)
self.dim = dim
self.depth = depth
self.layers = nn.ModuleList([])
self.has_pos_emb = position_infused_attn
self.pia_pos_emb = FixedPositionalEmbedding(dim) if position_infused_attn else None
self.rotary_pos_emb = always(None)
assert rel_pos_num_buckets <= rel_pos_max_distance, 'number of relative position buckets must be less than the relative position max distance'
self.rel_pos = None
self.pre_norm = pre_norm
self.residual_attn = residual_attn
self.cross_residual_attn = cross_residual_attn
norm_class = ScaleNorm if use_scalenorm else nn.LayerNorm
norm_class = RMSNorm if use_rmsnorm else norm_class
norm_fn = partial(norm_class, dim)
norm_fn = nn.Identity if use_rezero else norm_fn
branch_fn = Rezero if use_rezero else None
if cross_attend and not only_cross:
default_block = ('a', 'c', 'f')
elif cross_attend and only_cross:
default_block = ('c', 'f')
else:
default_block = ('a', 'f')
if macaron:
default_block = ('f',) + default_block
if exists(custom_layers):
layer_types = custom_layers
elif exists(par_ratio):
par_depth = depth * len(default_block)
assert 1 < par_ratio <= par_depth, 'par ratio out of range'
default_block = tuple(filter(not_equals('f'), default_block))
par_attn = par_depth // par_ratio
depth_cut = par_depth * 2 // 3 # 2 / 3 attention layer cutoff suggested by PAR paper
par_width = (depth_cut + depth_cut // par_attn) // par_attn
assert len(default_block) <= par_width, 'default block is too large for par_ratio'
par_block = default_block + ('f',) * (par_width - len(default_block))
par_head = par_block * par_attn
layer_types = par_head + ('f',) * (par_depth - len(par_head))
elif exists(sandwich_coef):
assert sandwich_coef > 0 and sandwich_coef <= depth, 'sandwich coefficient should be less than the depth'
layer_types = ('a',) * sandwich_coef + default_block * (depth - sandwich_coef) + ('f',) * sandwich_coef
else:
layer_types = default_block * depth
self.layer_types = layer_types
self.num_attn_layers = len(list(filter(equals('a'), layer_types)))
for layer_type in self.layer_types:
if layer_type == 'a':
layer = Attention(dim, heads=heads, causal=causal, **attn_kwargs)
elif layer_type == 'c':
layer = Attention(dim, heads=heads, **attn_kwargs)
elif layer_type == 'f':
layer = FeedForward(dim, **ff_kwargs)
layer = layer if not macaron else Scale(0.5, layer)
else:
raise Exception(f'invalid layer type {layer_type}')
if isinstance(layer, Attention) and exists(branch_fn):
layer = branch_fn(layer)
if gate_residual:
residual_fn = GRUGating(dim)
else:
residual_fn = Residual()
self.layers.append(nn.ModuleList([
norm_fn(),
layer,
residual_fn
]))
def forward(
self,
x,
context=None,
mask=None,
context_mask=None,
mems=None,
return_hiddens=False
):
hiddens = []
intermediates = []
prev_attn = None
prev_cross_attn = None
mems = mems.copy() if exists(mems) else [None] * self.num_attn_layers
for ind, (layer_type, (norm, block, residual_fn)) in enumerate(zip(self.layer_types, self.layers)):
is_last = ind == (len(self.layers) - 1)
if layer_type == 'a':
hiddens.append(x)
layer_mem = mems.pop(0)
residual = x
if self.pre_norm:
x = norm(x)
if layer_type == 'a':
out, inter = block(x, mask=mask, sinusoidal_emb=self.pia_pos_emb, rel_pos=self.rel_pos,
prev_attn=prev_attn, mem=layer_mem)
elif layer_type == 'c':
out, inter = block(x, context=context, mask=mask, context_mask=context_mask, prev_attn=prev_cross_attn)
elif layer_type == 'f':
out = block(x)
x = residual_fn(out, residual)
if layer_type in ('a', 'c'):
intermediates.append(inter)
if layer_type == 'a' and self.residual_attn:
prev_attn = inter.pre_softmax_attn
elif layer_type == 'c' and self.cross_residual_attn:
prev_cross_attn = inter.pre_softmax_attn
if not self.pre_norm and not is_last:
x = norm(x)
if return_hiddens:
intermediates = LayerIntermediates(
hiddens=hiddens,
attn_intermediates=intermediates
)
return x, intermediates
return x
class Encoder(AttentionLayers):
def __init__(self, **kwargs):
assert 'causal' not in kwargs, 'cannot set causality on encoder'
super().__init__(causal=False, **kwargs)
class TransformerWrapper(nn.Module):
def __init__(
self,
*,
num_tokens,
max_seq_len,
attn_layers,
emb_dim=None,
max_mem_len=0.,
emb_dropout=0.,
num_memory_tokens=None,
tie_embedding=False,
use_pos_emb=True
):
super().__init__()
assert isinstance(attn_layers, AttentionLayers), 'attention layers must be one of Encoder or Decoder'
dim = attn_layers.dim
emb_dim = default(emb_dim, dim)
self.max_seq_len = max_seq_len
self.max_mem_len = max_mem_len
self.num_tokens = num_tokens
self.token_emb = nn.Embedding(num_tokens, emb_dim)
self.pos_emb = AbsolutePositionalEmbedding(emb_dim, max_seq_len) if (
use_pos_emb and not attn_layers.has_pos_emb) else always(0)
self.emb_dropout = nn.Dropout(emb_dropout)
self.project_emb = nn.Linear(emb_dim, dim) if emb_dim != dim else nn.Identity()
self.attn_layers = attn_layers
self.norm = nn.LayerNorm(dim)
self.init_()
self.to_logits = nn.Linear(dim, num_tokens) if not tie_embedding else lambda t: t @ self.token_emb.weight.t()
# memory tokens (like [cls]) from Memory Transformers paper
num_memory_tokens = default(num_memory_tokens, 0)
self.num_memory_tokens = num_memory_tokens
if num_memory_tokens > 0:
self.memory_tokens = nn.Parameter(torch.randn(num_memory_tokens, dim))
# let funnel encoder know number of memory tokens, if specified
if hasattr(attn_layers, 'num_memory_tokens'):
attn_layers.num_memory_tokens = num_memory_tokens
def init_(self):
nn.init.normal_(self.token_emb.weight, std=0.02)
def forward(
self,
x,
return_embeddings=False,
mask=None,
return_mems=False,
return_attn=False,
mems=None,
**kwargs
):
b, n, device, num_mem = *x.shape, x.device, self.num_memory_tokens
x = self.token_emb(x)
x += self.pos_emb(x)
x = self.emb_dropout(x)
x = self.project_emb(x)
if num_mem > 0:
mem = repeat(self.memory_tokens, 'n d -> b n d', b=b)
x = torch.cat((mem, x), dim=1)
# auto-handle masking after appending memory tokens
if exists(mask):
mask = F.pad(mask, (num_mem, 0), value=True)
x, intermediates = self.attn_layers(x, mask=mask, mems=mems, return_hiddens=True, **kwargs)
x = self.norm(x)
mem, x = x[:, :num_mem], x[:, num_mem:]
out = self.to_logits(x) if not return_embeddings else x
if return_mems:
hiddens = intermediates.hiddens
new_mems = list(map(lambda pair: torch.cat(pair, dim=-2), zip(mems, hiddens))) if exists(mems) else hiddens
new_mems = list(map(lambda t: t[..., -self.max_mem_len:, :].detach(), new_mems))
return out, new_mems
if return_attn:
attn_maps = list(map(lambda t: t.post_softmax_attn, intermediates.attn_intermediates))
return out, attn_maps
return out
\ No newline at end of file
# 模型唯一标识
modelCode=561
# 模型名称
modelName=dynamicrafter_pytorch
# 模型描述
modelDescription=dynamicrafter可以通过文本描述将静态图变为动态视频
# 应用场景
appScenario=推理,AIGC,媒体,科研,教育
# 框架类型
frameType=pytorch
a man in an astronaut suit playing a guitar
riding a bike under a bridge
time-lapse of a blooming flower with leaves and a stem
fireworks display
a beautiful woman with long hair and a dress blowing in the wind
pouring beer into a glass of ice and beer
a robot is walking through a destroyed city
a group of penguins walking on a beach
\ No newline at end of file
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