Commit 5e2c95b7 authored by wuxk1's avatar wuxk1
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init commit for comui

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import torch
import torch.nn as nn
import comfy.ops
from comfy.ldm.modules.diffusionmodules.mmdit import Mlp, TimestepEmbedder, PatchEmbed
from comfy.ldm.modules.diffusionmodules.util import timestep_embedding
from torch.utils import checkpoint
from .attn_layers import Attention, CrossAttention
from .poolers import AttentionPool
from .posemb_layers import get_2d_rotary_pos_embed, get_fill_resize_and_crop
def calc_rope(x, patch_size, head_size):
th = (x.shape[2] + (patch_size // 2)) // patch_size
tw = (x.shape[3] + (patch_size // 2)) // patch_size
base_size = 512 // 8 // patch_size
start, stop = get_fill_resize_and_crop((th, tw), base_size)
sub_args = [start, stop, (th, tw)]
# head_size = HUNYUAN_DIT_CONFIG['DiT-g/2']['hidden_size'] // HUNYUAN_DIT_CONFIG['DiT-g/2']['num_heads']
rope = get_2d_rotary_pos_embed(head_size, *sub_args)
rope = (rope[0].to(x), rope[1].to(x))
return rope
def modulate(x, shift, scale):
return x * (1 + scale.unsqueeze(1)) + shift.unsqueeze(1)
class HunYuanDiTBlock(nn.Module):
"""
A HunYuanDiT block with `add` conditioning.
"""
def __init__(self,
hidden_size,
c_emb_size,
num_heads,
mlp_ratio=4.0,
text_states_dim=1024,
qk_norm=False,
norm_type="layer",
skip=False,
attn_precision=None,
dtype=None,
device=None,
operations=None,
):
super().__init__()
use_ele_affine = True
if norm_type == "layer":
norm_layer = operations.LayerNorm
elif norm_type == "rms":
norm_layer = operations.RMSNorm
else:
raise ValueError(f"Unknown norm_type: {norm_type}")
# ========================= Self-Attention =========================
self.norm1 = norm_layer(hidden_size, elementwise_affine=use_ele_affine, eps=1e-6, dtype=dtype, device=device)
self.attn1 = Attention(hidden_size, num_heads=num_heads, qkv_bias=True, qk_norm=qk_norm, attn_precision=attn_precision, dtype=dtype, device=device, operations=operations)
# ========================= FFN =========================
self.norm2 = norm_layer(hidden_size, elementwise_affine=use_ele_affine, eps=1e-6, dtype=dtype, device=device)
mlp_hidden_dim = int(hidden_size * mlp_ratio)
approx_gelu = lambda: nn.GELU(approximate="tanh")
self.mlp = Mlp(in_features=hidden_size, hidden_features=mlp_hidden_dim, act_layer=approx_gelu, drop=0, dtype=dtype, device=device, operations=operations)
# ========================= Add =========================
# Simply use add like SDXL.
self.default_modulation = nn.Sequential(
nn.SiLU(),
operations.Linear(c_emb_size, hidden_size, bias=True, dtype=dtype, device=device)
)
# ========================= Cross-Attention =========================
self.attn2 = CrossAttention(hidden_size, text_states_dim, num_heads=num_heads, qkv_bias=True,
qk_norm=qk_norm, attn_precision=attn_precision, dtype=dtype, device=device, operations=operations)
self.norm3 = norm_layer(hidden_size, elementwise_affine=True, eps=1e-6, dtype=dtype, device=device)
# ========================= Skip Connection =========================
if skip:
self.skip_norm = norm_layer(2 * hidden_size, elementwise_affine=True, eps=1e-6, dtype=dtype, device=device)
self.skip_linear = operations.Linear(2 * hidden_size, hidden_size, dtype=dtype, device=device)
else:
self.skip_linear = None
self.gradient_checkpointing = False
def _forward(self, x, c=None, text_states=None, freq_cis_img=None, skip=None):
# Long Skip Connection
if self.skip_linear is not None:
cat = torch.cat([x, skip], dim=-1)
if cat.dtype != x.dtype:
cat = cat.to(x.dtype)
cat = self.skip_norm(cat)
x = self.skip_linear(cat)
# Self-Attention
shift_msa = self.default_modulation(c).unsqueeze(dim=1)
attn_inputs = (
self.norm1(x) + shift_msa, freq_cis_img,
)
x = x + self.attn1(*attn_inputs)[0]
# Cross-Attention
cross_inputs = (
self.norm3(x), text_states, freq_cis_img
)
x = x + self.attn2(*cross_inputs)[0]
# FFN Layer
mlp_inputs = self.norm2(x)
x = x + self.mlp(mlp_inputs)
return x
def forward(self, x, c=None, text_states=None, freq_cis_img=None, skip=None):
if self.gradient_checkpointing and self.training:
return checkpoint.checkpoint(self._forward, x, c, text_states, freq_cis_img, skip)
return self._forward(x, c, text_states, freq_cis_img, skip)
class FinalLayer(nn.Module):
"""
The final layer of HunYuanDiT.
"""
def __init__(self, final_hidden_size, c_emb_size, patch_size, out_channels, dtype=None, device=None, operations=None):
super().__init__()
self.norm_final = operations.LayerNorm(final_hidden_size, elementwise_affine=False, eps=1e-6, dtype=dtype, device=device)
self.linear = operations.Linear(final_hidden_size, patch_size * patch_size * out_channels, bias=True, dtype=dtype, device=device)
self.adaLN_modulation = nn.Sequential(
nn.SiLU(),
operations.Linear(c_emb_size, 2 * final_hidden_size, bias=True, dtype=dtype, device=device)
)
def forward(self, x, c):
shift, scale = self.adaLN_modulation(c).chunk(2, dim=1)
x = modulate(self.norm_final(x), shift, scale)
x = self.linear(x)
return x
class HunYuanDiT(nn.Module):
"""
HunYuanDiT: Diffusion model with a Transformer backbone.
Inherit ModelMixin and ConfigMixin to be compatible with the sampler StableDiffusionPipeline of diffusers.
Inherit PeftAdapterMixin to be compatible with the PEFT training pipeline.
Parameters
----------
args: argparse.Namespace
The arguments parsed by argparse.
input_size: tuple
The size of the input image.
patch_size: int
The size of the patch.
in_channels: int
The number of input channels.
hidden_size: int
The hidden size of the transformer backbone.
depth: int
The number of transformer blocks.
num_heads: int
The number of attention heads.
mlp_ratio: float
The ratio of the hidden size of the MLP in the transformer block.
log_fn: callable
The logging function.
"""
#@register_to_config
def __init__(self,
input_size: tuple = 32,
patch_size: int = 2,
in_channels: int = 4,
hidden_size: int = 1152,
depth: int = 28,
num_heads: int = 16,
mlp_ratio: float = 4.0,
text_states_dim = 1024,
text_states_dim_t5 = 2048,
text_len = 77,
text_len_t5 = 256,
qk_norm = True,# See http://arxiv.org/abs/2302.05442 for details.
size_cond = False,
use_style_cond = False,
learn_sigma = True,
norm = "layer",
log_fn: callable = print,
attn_precision=None,
dtype=None,
device=None,
operations=None,
**kwargs,
):
super().__init__()
self.log_fn = log_fn
self.depth = depth
self.learn_sigma = learn_sigma
self.in_channels = in_channels
self.out_channels = in_channels * 2 if learn_sigma else in_channels
self.patch_size = patch_size
self.num_heads = num_heads
self.hidden_size = hidden_size
self.text_states_dim = text_states_dim
self.text_states_dim_t5 = text_states_dim_t5
self.text_len = text_len
self.text_len_t5 = text_len_t5
self.size_cond = size_cond
self.use_style_cond = use_style_cond
self.norm = norm
self.dtype = dtype
#import pdb
#pdb.set_trace()
self.mlp_t5 = nn.Sequential(
operations.Linear(self.text_states_dim_t5, self.text_states_dim_t5 * 4, bias=True, dtype=dtype, device=device),
nn.SiLU(),
operations.Linear(self.text_states_dim_t5 * 4, self.text_states_dim, bias=True, dtype=dtype, device=device),
)
# learnable replace
self.text_embedding_padding = nn.Parameter(
torch.empty(self.text_len + self.text_len_t5, self.text_states_dim, dtype=dtype, device=device))
# Attention pooling
pooler_out_dim = 1024
self.pooler = AttentionPool(self.text_len_t5, self.text_states_dim_t5, num_heads=8, output_dim=pooler_out_dim, dtype=dtype, device=device, operations=operations)
# Dimension of the extra input vectors
self.extra_in_dim = pooler_out_dim
if self.size_cond:
# Image size and crop size conditions
self.extra_in_dim += 6 * 256
if self.use_style_cond:
# Here we use a default learned embedder layer for future extension.
self.style_embedder = operations.Embedding(1, hidden_size, dtype=dtype, device=device)
self.extra_in_dim += hidden_size
# Text embedding for `add`
self.x_embedder = PatchEmbed(input_size, patch_size, in_channels, hidden_size, dtype=dtype, device=device, operations=operations)
self.t_embedder = TimestepEmbedder(hidden_size, dtype=dtype, device=device, operations=operations)
self.extra_embedder = nn.Sequential(
operations.Linear(self.extra_in_dim, hidden_size * 4, dtype=dtype, device=device),
nn.SiLU(),
operations.Linear(hidden_size * 4, hidden_size, bias=True, dtype=dtype, device=device),
)
# HUnYuanDiT Blocks
self.blocks = nn.ModuleList([
HunYuanDiTBlock(hidden_size=hidden_size,
c_emb_size=hidden_size,
num_heads=num_heads,
mlp_ratio=mlp_ratio,
text_states_dim=self.text_states_dim,
qk_norm=qk_norm,
norm_type=self.norm,
skip=layer > depth // 2,
attn_precision=attn_precision,
dtype=dtype,
device=device,
operations=operations,
)
for layer in range(depth)
])
self.final_layer = FinalLayer(hidden_size, hidden_size, patch_size, self.out_channels, dtype=dtype, device=device, operations=operations)
self.unpatchify_channels = self.out_channels
def forward(self,
x,
t,
context,#encoder_hidden_states=None,
text_embedding_mask=None,
encoder_hidden_states_t5=None,
text_embedding_mask_t5=None,
image_meta_size=None,
style=None,
return_dict=False,
control=None,
transformer_options={},
):
"""
Forward pass of the encoder.
Parameters
----------
x: torch.Tensor
(B, D, H, W)
t: torch.Tensor
(B)
encoder_hidden_states: torch.Tensor
CLIP text embedding, (B, L_clip, D)
text_embedding_mask: torch.Tensor
CLIP text embedding mask, (B, L_clip)
encoder_hidden_states_t5: torch.Tensor
T5 text embedding, (B, L_t5, D)
text_embedding_mask_t5: torch.Tensor
T5 text embedding mask, (B, L_t5)
image_meta_size: torch.Tensor
(B, 6)
style: torch.Tensor
(B)
cos_cis_img: torch.Tensor
sin_cis_img: torch.Tensor
return_dict: bool
Whether to return a dictionary.
"""
patches_replace = transformer_options.get("patches_replace", {})
encoder_hidden_states = context
text_states = encoder_hidden_states # 2,77,1024
text_states_t5 = encoder_hidden_states_t5 # 2,256,2048
text_states_mask = text_embedding_mask.bool() # 2,77
text_states_t5_mask = text_embedding_mask_t5.bool() # 2,256
b_t5, l_t5, c_t5 = text_states_t5.shape
text_states_t5 = self.mlp_t5(text_states_t5.view(-1, c_t5)).view(b_t5, l_t5, -1)
padding = comfy.ops.cast_to_input(self.text_embedding_padding, text_states)
text_states[:,-self.text_len:] = torch.where(text_states_mask[:,-self.text_len:].unsqueeze(2), text_states[:,-self.text_len:], padding[:self.text_len])
text_states_t5[:,-self.text_len_t5:] = torch.where(text_states_t5_mask[:,-self.text_len_t5:].unsqueeze(2), text_states_t5[:,-self.text_len_t5:], padding[self.text_len:])
text_states = torch.cat([text_states, text_states_t5], dim=1) # 2,205,1024
# clip_t5_mask = torch.cat([text_states_mask, text_states_t5_mask], dim=-1)
_, _, oh, ow = x.shape
th, tw = (oh + (self.patch_size // 2)) // self.patch_size, (ow + (self.patch_size // 2)) // self.patch_size
# Get image RoPE embedding according to `reso`lution.
freqs_cis_img = calc_rope(x, self.patch_size, self.hidden_size // self.num_heads) #(cos_cis_img, sin_cis_img)
# ========================= Build time and image embedding =========================
t = self.t_embedder(t, dtype=x.dtype)
x = self.x_embedder(x)
# ========================= Concatenate all extra vectors =========================
# Build text tokens with pooling
extra_vec = self.pooler(encoder_hidden_states_t5)
# Build image meta size tokens if applicable
if self.size_cond:
image_meta_size = timestep_embedding(image_meta_size.view(-1), 256).to(x.dtype) # [B * 6, 256]
image_meta_size = image_meta_size.view(-1, 6 * 256)
extra_vec = torch.cat([extra_vec, image_meta_size], dim=1) # [B, D + 6 * 256]
# Build style tokens
if self.use_style_cond:
if style is None:
style = torch.zeros((extra_vec.shape[0],), device=x.device, dtype=torch.int)
style_embedding = self.style_embedder(style, out_dtype=x.dtype)
extra_vec = torch.cat([extra_vec, style_embedding], dim=1)
# Concatenate all extra vectors
c = t + self.extra_embedder(extra_vec) # [B, D]
blocks_replace = patches_replace.get("dit", {})
controls = None
if control:
controls = control.get("output", None)
# ========================= Forward pass through HunYuanDiT blocks =========================
skips = []
for layer, block in enumerate(self.blocks):
if layer > self.depth // 2:
if controls is not None:
skip = skips.pop() + controls.pop().to(dtype=x.dtype)
else:
skip = skips.pop()
else:
skip = None
if ("double_block", layer) in blocks_replace:
def block_wrap(args):
out = {}
out["img"] = block(args["img"], args["vec"], args["txt"], args["pe"], args["skip"])
return out
out = blocks_replace[("double_block", layer)]({"img": x, "txt": text_states, "vec": c, "pe": freqs_cis_img, "skip": skip}, {"original_block": block_wrap})
x = out["img"]
else:
x = block(x, c, text_states, freqs_cis_img, skip) # (N, L, D)
if layer < (self.depth // 2 - 1):
skips.append(x)
if controls is not None and len(controls) != 0:
raise ValueError("The number of controls is not equal to the number of skip connections.")
# ========================= Final layer =========================
x = self.final_layer(x, c) # (N, L, patch_size ** 2 * out_channels)
x = self.unpatchify(x, th, tw) # (N, out_channels, H, W)
if return_dict:
return {'x': x}
if self.learn_sigma:
return x[:,:self.out_channels // 2,:oh,:ow]
return x[:,:,:oh,:ow]
def unpatchify(self, x, h, w):
"""
x: (N, T, patch_size**2 * C)
imgs: (N, H, W, C)
"""
c = self.unpatchify_channels
p = self.x_embedder.patch_size[0]
# h = w = int(x.shape[1] ** 0.5)
assert h * w == x.shape[1]
x = x.reshape(shape=(x.shape[0], h, w, p, p, c))
x = torch.einsum('nhwpqc->nchpwq', x)
imgs = x.reshape(shape=(x.shape[0], c, h * p, w * p))
return imgs
import torch
import torch.nn as nn
from comfy.ldm.modules.attention import optimized_attention
import comfy.ops
class AttentionPool(nn.Module):
def __init__(self, spacial_dim: int, embed_dim: int, num_heads: int, output_dim: int = None, dtype=None, device=None, operations=None):
super().__init__()
self.positional_embedding = nn.Parameter(torch.empty(spacial_dim + 1, embed_dim, dtype=dtype, device=device))
self.k_proj = operations.Linear(embed_dim, embed_dim, dtype=dtype, device=device)
self.q_proj = operations.Linear(embed_dim, embed_dim, dtype=dtype, device=device)
self.v_proj = operations.Linear(embed_dim, embed_dim, dtype=dtype, device=device)
self.c_proj = operations.Linear(embed_dim, output_dim or embed_dim, dtype=dtype, device=device)
self.num_heads = num_heads
self.embed_dim = embed_dim
def forward(self, x):
x = x[:,:self.positional_embedding.shape[0] - 1]
x = x.permute(1, 0, 2) # NLC -> LNC
x = torch.cat([x.mean(dim=0, keepdim=True), x], dim=0) # (L+1)NC
x = x + comfy.ops.cast_to_input(self.positional_embedding[:, None, :], x) # (L+1)NC
q = self.q_proj(x[:1])
k = self.k_proj(x)
v = self.v_proj(x)
batch_size = q.shape[1]
head_dim = self.embed_dim // self.num_heads
q = q.view(1, batch_size * self.num_heads, head_dim).transpose(0, 1).view(batch_size, self.num_heads, -1, head_dim)
k = k.view(k.shape[0], batch_size * self.num_heads, head_dim).transpose(0, 1).view(batch_size, self.num_heads, -1, head_dim)
v = v.view(v.shape[0], batch_size * self.num_heads, head_dim).transpose(0, 1).view(batch_size, self.num_heads, -1, head_dim)
attn_output = optimized_attention(q, k, v, self.num_heads, skip_reshape=True).transpose(0, 1)
attn_output = self.c_proj(attn_output)
return attn_output.squeeze(0)
import torch
import numpy as np
from typing import Union
def _to_tuple(x):
if isinstance(x, int):
return x, x
else:
return x
def get_fill_resize_and_crop(src, tgt):
th, tw = _to_tuple(tgt)
h, w = _to_tuple(src)
tr = th / tw # base resolution
r = h / w # target resolution
# resize
if r > tr:
resize_height = th
resize_width = int(round(th / h * w))
else:
resize_width = tw
resize_height = int(round(tw / w * h)) # resize the target resolution down based on the base resolution
crop_top = int(round((th - resize_height) / 2.0))
crop_left = int(round((tw - resize_width) / 2.0))
return (crop_top, crop_left), (crop_top + resize_height, crop_left + resize_width)
def get_meshgrid(start, *args):
if len(args) == 0:
# start is grid_size
num = _to_tuple(start)
start = (0, 0)
stop = num
elif len(args) == 1:
# start is start, args[0] is stop, step is 1
start = _to_tuple(start)
stop = _to_tuple(args[0])
num = (stop[0] - start[0], stop[1] - start[1])
elif len(args) == 2:
# start is start, args[0] is stop, args[1] is num
start = _to_tuple(start)
stop = _to_tuple(args[0])
num = _to_tuple(args[1])
else:
raise ValueError(f"len(args) should be 0, 1 or 2, but got {len(args)}")
grid_h = np.linspace(start[0], stop[0], num[0], endpoint=False, dtype=np.float32)
grid_w = np.linspace(start[1], stop[1], num[1], endpoint=False, dtype=np.float32)
grid = np.meshgrid(grid_w, grid_h) # here w goes first
grid = np.stack(grid, axis=0) # [2, W, H]
return grid
#################################################################################
# Sine/Cosine Positional Embedding Functions #
#################################################################################
# https://github.com/facebookresearch/mae/blob/main/util/pos_embed.py
def get_2d_sincos_pos_embed(embed_dim, start, *args, cls_token=False, extra_tokens=0):
"""
grid_size: int of the grid height and width
return:
pos_embed: [grid_size*grid_size, embed_dim] or [1+grid_size*grid_size, embed_dim] (w/ or w/o cls_token)
"""
grid = get_meshgrid(start, *args) # [2, H, w]
# grid_h = np.arange(grid_size, dtype=np.float32)
# grid_w = np.arange(grid_size, dtype=np.float32)
# grid = np.meshgrid(grid_w, grid_h) # here w goes first
# grid = np.stack(grid, axis=0) # [2, W, H]
grid = grid.reshape([2, 1, *grid.shape[1:]])
pos_embed = get_2d_sincos_pos_embed_from_grid(embed_dim, grid)
if cls_token and extra_tokens > 0:
pos_embed = np.concatenate([np.zeros([extra_tokens, embed_dim]), pos_embed], axis=0)
return pos_embed
def get_2d_sincos_pos_embed_from_grid(embed_dim, grid):
assert embed_dim % 2 == 0
# use half of dimensions to encode grid_h
emb_h = get_1d_sincos_pos_embed_from_grid(embed_dim // 2, grid[0]) # (H*W, D/2)
emb_w = get_1d_sincos_pos_embed_from_grid(embed_dim // 2, grid[1]) # (H*W, D/2)
emb = np.concatenate([emb_h, emb_w], axis=1) # (H*W, D)
return emb
def get_1d_sincos_pos_embed_from_grid(embed_dim, pos):
"""
embed_dim: output dimension for each position
pos: a list of positions to be encoded: size (W,H)
out: (M, D)
"""
assert embed_dim % 2 == 0
omega = np.arange(embed_dim // 2, dtype=np.float64)
omega /= embed_dim / 2.
omega = 1. / 10000**omega # (D/2,)
pos = pos.reshape(-1) # (M,)
out = np.einsum('m,d->md', pos, omega) # (M, D/2), outer product
emb_sin = np.sin(out) # (M, D/2)
emb_cos = np.cos(out) # (M, D/2)
emb = np.concatenate([emb_sin, emb_cos], axis=1) # (M, D)
return emb
#################################################################################
# Rotary Positional Embedding Functions #
#################################################################################
# https://github.com/facebookresearch/llama/blob/main/llama/model.py#L443
def get_2d_rotary_pos_embed(embed_dim, start, *args, use_real=True):
"""
This is a 2d version of precompute_freqs_cis, which is a RoPE for image tokens with 2d structure.
Parameters
----------
embed_dim: int
embedding dimension size
start: int or tuple of int
If len(args) == 0, start is num; If len(args) == 1, start is start, args[0] is stop, step is 1;
If len(args) == 2, start is start, args[0] is stop, args[1] is num.
use_real: bool
If True, return real part and imaginary part separately. Otherwise, return complex numbers.
Returns
-------
pos_embed: torch.Tensor
[HW, D/2]
"""
grid = get_meshgrid(start, *args) # [2, H, w]
grid = grid.reshape([2, 1, *grid.shape[1:]]) # Returns a sampling matrix with the same resolution as the target resolution
pos_embed = get_2d_rotary_pos_embed_from_grid(embed_dim, grid, use_real=use_real)
return pos_embed
def get_2d_rotary_pos_embed_from_grid(embed_dim, grid, use_real=False):
assert embed_dim % 4 == 0
# use half of dimensions to encode grid_h
emb_h = get_1d_rotary_pos_embed(embed_dim // 2, grid[0].reshape(-1), use_real=use_real) # (H*W, D/4)
emb_w = get_1d_rotary_pos_embed(embed_dim // 2, grid[1].reshape(-1), use_real=use_real) # (H*W, D/4)
if use_real:
cos = torch.cat([emb_h[0], emb_w[0]], dim=1) # (H*W, D/2)
sin = torch.cat([emb_h[1], emb_w[1]], dim=1) # (H*W, D/2)
return cos, sin
else:
emb = torch.cat([emb_h, emb_w], dim=1) # (H*W, D/2)
return emb
def get_1d_rotary_pos_embed(dim: int, pos: Union[np.ndarray, int], theta: float = 10000.0, use_real=False):
"""
Precompute the frequency tensor for complex exponentials (cis) with given dimensions.
This function calculates a frequency tensor with complex exponentials using the given dimension 'dim'
and the end index 'end'. The 'theta' parameter scales the frequencies.
The returned tensor contains complex values in complex64 data type.
Args:
dim (int): Dimension of the frequency tensor.
pos (np.ndarray, int): Position indices for the frequency tensor. [S] or scalar
theta (float, optional): Scaling factor for frequency computation. Defaults to 10000.0.
use_real (bool, optional): If True, return real part and imaginary part separately.
Otherwise, return complex numbers.
Returns:
torch.Tensor: Precomputed frequency tensor with complex exponentials. [S, D/2]
"""
if isinstance(pos, int):
pos = np.arange(pos)
freqs = 1.0 / (theta ** (torch.arange(0, dim, 2)[: (dim // 2)].float() / dim)) # [D/2]
t = torch.from_numpy(pos).to(freqs.device) # type: ignore # [S]
freqs = torch.outer(t, freqs).float() # type: ignore # [S, D/2]
if use_real:
freqs_cos = freqs.cos().repeat_interleave(2, dim=1) # [S, D]
freqs_sin = freqs.sin().repeat_interleave(2, dim=1) # [S, D]
return freqs_cos, freqs_sin
else:
freqs_cis = torch.polar(torch.ones_like(freqs), freqs) # complex64 # [S, D/2]
return freqs_cis
def calc_sizes(rope_img, patch_size, th, tw):
if rope_img == 'extend':
# Expansion mode
sub_args = [(th, tw)]
elif rope_img.startswith('base'):
# Based on the specified dimensions, other dimensions are obtained through interpolation.
base_size = int(rope_img[4:]) // 8 // patch_size
start, stop = get_fill_resize_and_crop((th, tw), base_size)
sub_args = [start, stop, (th, tw)]
else:
raise ValueError(f"Unknown rope_img: {rope_img}")
return sub_args
def init_image_posemb(rope_img,
resolutions,
patch_size,
hidden_size,
num_heads,
log_fn,
rope_real=True,
):
freqs_cis_img = {}
for reso in resolutions:
th, tw = reso.height // 8 // patch_size, reso.width // 8 // patch_size
sub_args = calc_sizes(rope_img, patch_size, th, tw)
freqs_cis_img[str(reso)] = get_2d_rotary_pos_embed(hidden_size // num_heads, *sub_args, use_real=rope_real)
log_fn(f" Using image RoPE ({rope_img}) ({'real' if rope_real else 'complex'}): {sub_args} | ({reso}) "
f"{freqs_cis_img[str(reso)][0].shape if rope_real else freqs_cis_img[str(reso)].shape}")
return freqs_cis_img
import torch
from torch import nn
import comfy.patcher_extension
import comfy.ldm.modules.attention
import comfy.ldm.common_dit
from einops import rearrange
import math
from typing import Dict, Optional, Tuple
from .symmetric_patchifier import SymmetricPatchifier, latent_to_pixel_coords
def get_timestep_embedding(
timesteps: torch.Tensor,
embedding_dim: int,
flip_sin_to_cos: bool = False,
downscale_freq_shift: float = 1,
scale: float = 1,
max_period: int = 10000,
):
"""
This matches the implementation in Denoising Diffusion Probabilistic Models: Create sinusoidal timestep embeddings.
Args
timesteps (torch.Tensor):
a 1-D Tensor of N indices, one per batch element. These may be fractional.
embedding_dim (int):
the dimension of the output.
flip_sin_to_cos (bool):
Whether the embedding order should be `cos, sin` (if True) or `sin, cos` (if False)
downscale_freq_shift (float):
Controls the delta between frequencies between dimensions
scale (float):
Scaling factor applied to the embeddings.
max_period (int):
Controls the maximum frequency of the embeddings
Returns
torch.Tensor: an [N x dim] Tensor of positional embeddings.
"""
assert len(timesteps.shape) == 1, "Timesteps should be a 1d-array"
half_dim = embedding_dim // 2
exponent = -math.log(max_period) * torch.arange(
start=0, end=half_dim, dtype=torch.float32, device=timesteps.device
)
exponent = exponent / (half_dim - downscale_freq_shift)
emb = torch.exp(exponent)
emb = timesteps[:, None].float() * emb[None, :]
# scale embeddings
emb = scale * emb
# concat sine and cosine embeddings
emb = torch.cat([torch.sin(emb), torch.cos(emb)], dim=-1)
# flip sine and cosine embeddings
if flip_sin_to_cos:
emb = torch.cat([emb[:, half_dim:], emb[:, :half_dim]], dim=-1)
# zero pad
if embedding_dim % 2 == 1:
emb = torch.nn.functional.pad(emb, (0, 1, 0, 0))
return emb
class TimestepEmbedding(nn.Module):
def __init__(
self,
in_channels: int,
time_embed_dim: int,
act_fn: str = "silu",
out_dim: int = None,
post_act_fn: Optional[str] = None,
cond_proj_dim=None,
sample_proj_bias=True,
dtype=None, device=None, operations=None,
):
super().__init__()
self.linear_1 = operations.Linear(in_channels, time_embed_dim, sample_proj_bias, dtype=dtype, device=device)
if cond_proj_dim is not None:
self.cond_proj = operations.Linear(cond_proj_dim, in_channels, bias=False, dtype=dtype, device=device)
else:
self.cond_proj = None
self.act = nn.SiLU()
if out_dim is not None:
time_embed_dim_out = out_dim
else:
time_embed_dim_out = time_embed_dim
self.linear_2 = operations.Linear(time_embed_dim, time_embed_dim_out, sample_proj_bias, dtype=dtype, device=device)
if post_act_fn is None:
self.post_act = None
# else:
# self.post_act = get_activation(post_act_fn)
def forward(self, sample, condition=None):
if condition is not None:
sample = sample + self.cond_proj(condition)
sample = self.linear_1(sample)
if self.act is not None:
sample = self.act(sample)
sample = self.linear_2(sample)
if self.post_act is not None:
sample = self.post_act(sample)
return sample
class Timesteps(nn.Module):
def __init__(self, num_channels: int, flip_sin_to_cos: bool, downscale_freq_shift: float, scale: int = 1):
super().__init__()
self.num_channels = num_channels
self.flip_sin_to_cos = flip_sin_to_cos
self.downscale_freq_shift = downscale_freq_shift
self.scale = scale
def forward(self, timesteps):
t_emb = get_timestep_embedding(
timesteps,
self.num_channels,
flip_sin_to_cos=self.flip_sin_to_cos,
downscale_freq_shift=self.downscale_freq_shift,
scale=self.scale,
)
return t_emb
class PixArtAlphaCombinedTimestepSizeEmbeddings(nn.Module):
"""
For PixArt-Alpha.
Reference:
https://github.com/PixArt-alpha/PixArt-alpha/blob/0f55e922376d8b797edd44d25d0e7464b260dcab/diffusion/model/nets/PixArtMS.py#L164C9-L168C29
"""
def __init__(self, embedding_dim, size_emb_dim, use_additional_conditions: bool = False, dtype=None, device=None, operations=None):
super().__init__()
self.outdim = size_emb_dim
self.time_proj = Timesteps(num_channels=256, flip_sin_to_cos=True, downscale_freq_shift=0)
self.timestep_embedder = TimestepEmbedding(in_channels=256, time_embed_dim=embedding_dim, dtype=dtype, device=device, operations=operations)
def forward(self, timestep, resolution, aspect_ratio, batch_size, hidden_dtype):
timesteps_proj = self.time_proj(timestep)
timesteps_emb = self.timestep_embedder(timesteps_proj.to(dtype=hidden_dtype)) # (N, D)
return timesteps_emb
class AdaLayerNormSingle(nn.Module):
r"""
Norm layer adaptive layer norm single (adaLN-single).
As proposed in PixArt-Alpha (see: https://arxiv.org/abs/2310.00426; Section 2.3).
Parameters:
embedding_dim (`int`): The size of each embedding vector.
use_additional_conditions (`bool`): To use additional conditions for normalization or not.
"""
def __init__(self, embedding_dim: int, use_additional_conditions: bool = False, dtype=None, device=None, operations=None):
super().__init__()
self.emb = PixArtAlphaCombinedTimestepSizeEmbeddings(
embedding_dim, size_emb_dim=embedding_dim // 3, use_additional_conditions=use_additional_conditions, dtype=dtype, device=device, operations=operations
)
self.silu = nn.SiLU()
self.linear = operations.Linear(embedding_dim, 6 * embedding_dim, bias=True, dtype=dtype, device=device)
def forward(
self,
timestep: torch.Tensor,
added_cond_kwargs: Optional[Dict[str, torch.Tensor]] = None,
batch_size: Optional[int] = None,
hidden_dtype: Optional[torch.dtype] = None,
) -> Tuple[torch.Tensor, torch.Tensor, torch.Tensor, torch.Tensor, torch.Tensor]:
# No modulation happening here.
added_cond_kwargs = added_cond_kwargs or {"resolution": None, "aspect_ratio": None}
embedded_timestep = self.emb(timestep, **added_cond_kwargs, batch_size=batch_size, hidden_dtype=hidden_dtype)
return self.linear(self.silu(embedded_timestep)), embedded_timestep
class PixArtAlphaTextProjection(nn.Module):
"""
Projects caption embeddings. Also handles dropout for classifier-free guidance.
Adapted from https://github.com/PixArt-alpha/PixArt-alpha/blob/master/diffusion/model/nets/PixArt_blocks.py
"""
def __init__(self, in_features, hidden_size, out_features=None, act_fn="gelu_tanh", dtype=None, device=None, operations=None):
super().__init__()
if out_features is None:
out_features = hidden_size
self.linear_1 = operations.Linear(in_features=in_features, out_features=hidden_size, bias=True, dtype=dtype, device=device)
if act_fn == "gelu_tanh":
self.act_1 = nn.GELU(approximate="tanh")
elif act_fn == "silu":
self.act_1 = nn.SiLU()
else:
raise ValueError(f"Unknown activation function: {act_fn}")
self.linear_2 = operations.Linear(in_features=hidden_size, out_features=out_features, bias=True, dtype=dtype, device=device)
def forward(self, caption):
hidden_states = self.linear_1(caption)
hidden_states = self.act_1(hidden_states)
hidden_states = self.linear_2(hidden_states)
return hidden_states
class GELU_approx(nn.Module):
def __init__(self, dim_in, dim_out, dtype=None, device=None, operations=None):
super().__init__()
self.proj = operations.Linear(dim_in, dim_out, dtype=dtype, device=device)
def forward(self, x):
return torch.nn.functional.gelu(self.proj(x), approximate="tanh")
class FeedForward(nn.Module):
def __init__(self, dim, dim_out, mult=4, glu=False, dropout=0., dtype=None, device=None, operations=None):
super().__init__()
inner_dim = int(dim * mult)
project_in = GELU_approx(dim, inner_dim, dtype=dtype, device=device, operations=operations)
self.net = nn.Sequential(
project_in,
nn.Dropout(dropout),
operations.Linear(inner_dim, dim_out, dtype=dtype, device=device)
)
def forward(self, x):
return self.net(x)
def apply_rotary_emb(input_tensor, freqs_cis): #TODO: remove duplicate funcs and pick the best/fastest one
cos_freqs = freqs_cis[0]
sin_freqs = freqs_cis[1]
t_dup = rearrange(input_tensor, "... (d r) -> ... d r", r=2)
t1, t2 = t_dup.unbind(dim=-1)
t_dup = torch.stack((-t2, t1), dim=-1)
input_tensor_rot = rearrange(t_dup, "... d r -> ... (d r)")
out = input_tensor * cos_freqs + input_tensor_rot * sin_freqs
return out
class CrossAttention(nn.Module):
def __init__(self, query_dim, context_dim=None, heads=8, dim_head=64, dropout=0., attn_precision=None, dtype=None, device=None, operations=None):
super().__init__()
inner_dim = dim_head * heads
context_dim = query_dim if context_dim is None else context_dim
self.attn_precision = attn_precision
self.heads = heads
self.dim_head = dim_head
self.q_norm = operations.RMSNorm(inner_dim, eps=1e-5, dtype=dtype, device=device)
self.k_norm = operations.RMSNorm(inner_dim, eps=1e-5, dtype=dtype, device=device)
self.to_q = operations.Linear(query_dim, inner_dim, bias=True, dtype=dtype, device=device)
self.to_k = operations.Linear(context_dim, inner_dim, bias=True, dtype=dtype, device=device)
self.to_v = operations.Linear(context_dim, inner_dim, bias=True, dtype=dtype, device=device)
self.to_out = nn.Sequential(operations.Linear(inner_dim, query_dim, dtype=dtype, device=device), nn.Dropout(dropout))
def forward(self, x, context=None, mask=None, pe=None):
q = self.to_q(x)
context = x if context is None else context
k = self.to_k(context)
v = self.to_v(context)
q = self.q_norm(q)
k = self.k_norm(k)
if pe is not None:
q = apply_rotary_emb(q, pe)
k = apply_rotary_emb(k, pe)
if mask is None:
out = comfy.ldm.modules.attention.optimized_attention(q, k, v, self.heads, attn_precision=self.attn_precision)
else:
out = comfy.ldm.modules.attention.optimized_attention_masked(q, k, v, self.heads, mask, attn_precision=self.attn_precision)
return self.to_out(out)
class BasicTransformerBlock(nn.Module):
def __init__(self, dim, n_heads, d_head, context_dim=None, attn_precision=None, dtype=None, device=None, operations=None):
super().__init__()
self.attn_precision = attn_precision
self.attn1 = CrossAttention(query_dim=dim, heads=n_heads, dim_head=d_head, context_dim=None, attn_precision=self.attn_precision, dtype=dtype, device=device, operations=operations)
self.ff = FeedForward(dim, dim_out=dim, glu=True, dtype=dtype, device=device, operations=operations)
self.attn2 = CrossAttention(query_dim=dim, context_dim=context_dim, heads=n_heads, dim_head=d_head, attn_precision=self.attn_precision, dtype=dtype, device=device, operations=operations)
self.scale_shift_table = nn.Parameter(torch.empty(6, dim, device=device, dtype=dtype))
def forward(self, x, context=None, attention_mask=None, timestep=None, pe=None):
shift_msa, scale_msa, gate_msa, shift_mlp, scale_mlp, gate_mlp = (self.scale_shift_table[None, None].to(device=x.device, dtype=x.dtype) + timestep.reshape(x.shape[0], timestep.shape[1], self.scale_shift_table.shape[0], -1)).unbind(dim=2)
x += self.attn1(comfy.ldm.common_dit.rms_norm(x) * (1 + scale_msa) + shift_msa, pe=pe) * gate_msa
x += self.attn2(x, context=context, mask=attention_mask)
y = comfy.ldm.common_dit.rms_norm(x) * (1 + scale_mlp) + shift_mlp
x += self.ff(y) * gate_mlp
return x
def get_fractional_positions(indices_grid, max_pos):
fractional_positions = torch.stack(
[
indices_grid[:, i] / max_pos[i]
for i in range(3)
],
dim=-1,
)
return fractional_positions
def precompute_freqs_cis(indices_grid, dim, out_dtype, theta=10000.0, max_pos=[20, 2048, 2048]):
dtype = torch.float32 #self.dtype
fractional_positions = get_fractional_positions(indices_grid, max_pos)
start = 1
end = theta
device = fractional_positions.device
indices = theta ** (
torch.linspace(
math.log(start, theta),
math.log(end, theta),
dim // 6,
device=device,
dtype=dtype,
)
)
indices = indices.to(dtype=dtype)
indices = indices * math.pi / 2
freqs = (
(indices * (fractional_positions.unsqueeze(-1) * 2 - 1))
.transpose(-1, -2)
.flatten(2)
)
cos_freq = freqs.cos().repeat_interleave(2, dim=-1)
sin_freq = freqs.sin().repeat_interleave(2, dim=-1)
if dim % 6 != 0:
cos_padding = torch.ones_like(cos_freq[:, :, : dim % 6])
sin_padding = torch.zeros_like(cos_freq[:, :, : dim % 6])
cos_freq = torch.cat([cos_padding, cos_freq], dim=-1)
sin_freq = torch.cat([sin_padding, sin_freq], dim=-1)
return cos_freq.to(out_dtype), sin_freq.to(out_dtype)
class LTXVModel(torch.nn.Module):
def __init__(self,
in_channels=128,
cross_attention_dim=2048,
attention_head_dim=64,
num_attention_heads=32,
caption_channels=4096,
num_layers=28,
positional_embedding_theta=10000.0,
positional_embedding_max_pos=[20, 2048, 2048],
causal_temporal_positioning=False,
vae_scale_factors=(8, 32, 32),
dtype=None, device=None, operations=None, **kwargs):
super().__init__()
self.generator = None
self.vae_scale_factors = vae_scale_factors
self.dtype = dtype
self.out_channels = in_channels
self.inner_dim = num_attention_heads * attention_head_dim
self.causal_temporal_positioning = causal_temporal_positioning
self.patchify_proj = operations.Linear(in_channels, self.inner_dim, bias=True, dtype=dtype, device=device)
self.adaln_single = AdaLayerNormSingle(
self.inner_dim, use_additional_conditions=False, dtype=dtype, device=device, operations=operations
)
# self.adaln_single.linear = operations.Linear(self.inner_dim, 4 * self.inner_dim, bias=True, dtype=dtype, device=device)
self.caption_projection = PixArtAlphaTextProjection(
in_features=caption_channels, hidden_size=self.inner_dim, dtype=dtype, device=device, operations=operations
)
self.transformer_blocks = nn.ModuleList(
[
BasicTransformerBlock(
self.inner_dim,
num_attention_heads,
attention_head_dim,
context_dim=cross_attention_dim,
# attn_precision=attn_precision,
dtype=dtype, device=device, operations=operations
)
for d in range(num_layers)
]
)
self.scale_shift_table = nn.Parameter(torch.empty(2, self.inner_dim, dtype=dtype, device=device))
self.norm_out = operations.LayerNorm(self.inner_dim, elementwise_affine=False, eps=1e-6, dtype=dtype, device=device)
self.proj_out = operations.Linear(self.inner_dim, self.out_channels, dtype=dtype, device=device)
self.patchifier = SymmetricPatchifier(1)
def forward(self, x, timestep, context, attention_mask, frame_rate=25, transformer_options={}, keyframe_idxs=None, **kwargs):
return comfy.patcher_extension.WrapperExecutor.new_class_executor(
self._forward,
self,
comfy.patcher_extension.get_all_wrappers(comfy.patcher_extension.WrappersMP.DIFFUSION_MODEL, transformer_options)
).execute(x, timestep, context, attention_mask, frame_rate, transformer_options, keyframe_idxs, **kwargs)
def _forward(self, x, timestep, context, attention_mask, frame_rate=25, transformer_options={}, keyframe_idxs=None, **kwargs):
patches_replace = transformer_options.get("patches_replace", {})
orig_shape = list(x.shape)
x, latent_coords = self.patchifier.patchify(x)
pixel_coords = latent_to_pixel_coords(
latent_coords=latent_coords,
scale_factors=self.vae_scale_factors,
causal_fix=self.causal_temporal_positioning,
)
if keyframe_idxs is not None:
pixel_coords[:, :, -keyframe_idxs.shape[2]:] = keyframe_idxs
fractional_coords = pixel_coords.to(torch.float32)
fractional_coords[:, 0] = fractional_coords[:, 0] * (1.0 / frame_rate)
x = self.patchify_proj(x)
timestep = timestep * 1000.0
if attention_mask is not None and not torch.is_floating_point(attention_mask):
attention_mask = (attention_mask - 1).to(x.dtype).reshape((attention_mask.shape[0], 1, -1, attention_mask.shape[-1])) * torch.finfo(x.dtype).max
pe = precompute_freqs_cis(fractional_coords, dim=self.inner_dim, out_dtype=x.dtype)
batch_size = x.shape[0]
timestep, embedded_timestep = self.adaln_single(
timestep.flatten(),
{"resolution": None, "aspect_ratio": None},
batch_size=batch_size,
hidden_dtype=x.dtype,
)
# Second dimension is 1 or number of tokens (if timestep_per_token)
timestep = timestep.view(batch_size, -1, timestep.shape[-1])
embedded_timestep = embedded_timestep.view(
batch_size, -1, embedded_timestep.shape[-1]
)
# 2. Blocks
if self.caption_projection is not None:
batch_size = x.shape[0]
context = self.caption_projection(context)
context = context.view(
batch_size, -1, x.shape[-1]
)
blocks_replace = patches_replace.get("dit", {})
for i, block in enumerate(self.transformer_blocks):
if ("double_block", i) in blocks_replace:
def block_wrap(args):
out = {}
out["img"] = block(args["img"], context=args["txt"], attention_mask=args["attention_mask"], timestep=args["vec"], pe=args["pe"])
return out
out = blocks_replace[("double_block", i)]({"img": x, "txt": context, "attention_mask": attention_mask, "vec": timestep, "pe": pe}, {"original_block": block_wrap})
x = out["img"]
else:
x = block(
x,
context=context,
attention_mask=attention_mask,
timestep=timestep,
pe=pe
)
# 3. Output
scale_shift_values = (
self.scale_shift_table[None, None].to(device=x.device, dtype=x.dtype) + embedded_timestep[:, :, None]
)
shift, scale = scale_shift_values[:, :, 0], scale_shift_values[:, :, 1]
x = self.norm_out(x)
# Modulation
x = x * (1 + scale) + shift
x = self.proj_out(x)
x = self.patchifier.unpatchify(
latents=x,
output_height=orig_shape[3],
output_width=orig_shape[4],
output_num_frames=orig_shape[2],
out_channels=orig_shape[1] // math.prod(self.patchifier.patch_size),
)
return x
from abc import ABC, abstractmethod
from typing import Tuple
import torch
from einops import rearrange
from torch import Tensor
def latent_to_pixel_coords(
latent_coords: Tensor, scale_factors: Tuple[int, int, int], causal_fix: bool = False
) -> Tensor:
"""
Converts latent coordinates to pixel coordinates by scaling them according to the VAE's
configuration.
Args:
latent_coords (Tensor): A tensor of shape [batch_size, 3, num_latents]
containing the latent corner coordinates of each token.
scale_factors (Tuple[int, int, int]): The scale factors of the VAE's latent space.
causal_fix (bool): Whether to take into account the different temporal scale
of the first frame. Default = False for backwards compatibility.
Returns:
Tensor: A tensor of pixel coordinates corresponding to the input latent coordinates.
"""
pixel_coords = (
latent_coords
* torch.tensor(scale_factors, device=latent_coords.device)[None, :, None]
)
if causal_fix:
# Fix temporal scale for first frame to 1 due to causality
pixel_coords[:, 0] = (pixel_coords[:, 0] + 1 - scale_factors[0]).clamp(min=0)
return pixel_coords
class Patchifier(ABC):
def __init__(self, patch_size: int):
super().__init__()
self._patch_size = (1, patch_size, patch_size)
@abstractmethod
def patchify(
self, latents: Tensor, frame_rates: Tensor, scale_grid: bool
) -> Tuple[Tensor, Tensor]:
pass
@abstractmethod
def unpatchify(
self,
latents: Tensor,
output_height: int,
output_width: int,
output_num_frames: int,
out_channels: int,
) -> Tuple[Tensor, Tensor]:
pass
@property
def patch_size(self):
return self._patch_size
def get_latent_coords(
self, latent_num_frames, latent_height, latent_width, batch_size, device
):
"""
Return a tensor of shape [batch_size, 3, num_patches] containing the
top-left corner latent coordinates of each latent patch.
The tensor is repeated for each batch element.
"""
latent_sample_coords = torch.meshgrid(
torch.arange(0, latent_num_frames, self._patch_size[0], device=device),
torch.arange(0, latent_height, self._patch_size[1], device=device),
torch.arange(0, latent_width, self._patch_size[2], device=device),
indexing="ij",
)
latent_sample_coords = torch.stack(latent_sample_coords, dim=0)
latent_coords = latent_sample_coords.unsqueeze(0).repeat(batch_size, 1, 1, 1, 1)
latent_coords = rearrange(
latent_coords, "b c f h w -> b c (f h w)", b=batch_size
)
return latent_coords
class SymmetricPatchifier(Patchifier):
def patchify(
self,
latents: Tensor,
) -> Tuple[Tensor, Tensor]:
b, _, f, h, w = latents.shape
latent_coords = self.get_latent_coords(f, h, w, b, latents.device)
latents = rearrange(
latents,
"b c (f p1) (h p2) (w p3) -> b (f h w) (c p1 p2 p3)",
p1=self._patch_size[0],
p2=self._patch_size[1],
p3=self._patch_size[2],
)
return latents, latent_coords
def unpatchify(
self,
latents: Tensor,
output_height: int,
output_width: int,
output_num_frames: int,
out_channels: int,
) -> Tuple[Tensor, Tensor]:
output_height = output_height // self._patch_size[1]
output_width = output_width // self._patch_size[2]
latents = rearrange(
latents,
"b (f h w) (c p q) -> b c f (h p) (w q) ",
f=output_num_frames,
h=output_height,
w=output_width,
p=self._patch_size[1],
q=self._patch_size[2],
)
return latents
from typing import Tuple, Union
import torch
import torch.nn as nn
import comfy.ops
ops = comfy.ops.disable_weight_init
class CausalConv3d(nn.Module):
def __init__(
self,
in_channels,
out_channels,
kernel_size: int = 3,
stride: Union[int, Tuple[int]] = 1,
dilation: int = 1,
groups: int = 1,
spatial_padding_mode: str = "zeros",
**kwargs,
):
super().__init__()
self.in_channels = in_channels
self.out_channels = out_channels
kernel_size = (kernel_size, kernel_size, kernel_size)
self.time_kernel_size = kernel_size[0]
dilation = (dilation, 1, 1)
height_pad = kernel_size[1] // 2
width_pad = kernel_size[2] // 2
padding = (0, height_pad, width_pad)
self.conv = ops.Conv3d(
in_channels,
out_channels,
kernel_size,
stride=stride,
dilation=dilation,
padding=padding,
padding_mode=spatial_padding_mode,
groups=groups,
)
def forward(self, x, causal: bool = True):
if causal:
first_frame_pad = x[:, :, :1, :, :].repeat(
(1, 1, self.time_kernel_size - 1, 1, 1)
)
x = torch.concatenate((first_frame_pad, x), dim=2)
else:
first_frame_pad = x[:, :, :1, :, :].repeat(
(1, 1, (self.time_kernel_size - 1) // 2, 1, 1)
)
last_frame_pad = x[:, :, -1:, :, :].repeat(
(1, 1, (self.time_kernel_size - 1) // 2, 1, 1)
)
x = torch.concatenate((first_frame_pad, x, last_frame_pad), dim=2)
x = self.conv(x)
return x
@property
def weight(self):
return self.conv.weight
from __future__ import annotations
import torch
from torch import nn
from functools import partial
import math
from einops import rearrange
from typing import List, Optional, Tuple, Union
from .conv_nd_factory import make_conv_nd, make_linear_nd
from .pixel_norm import PixelNorm
from ..model import PixArtAlphaCombinedTimestepSizeEmbeddings
import comfy.ops
ops = comfy.ops.disable_weight_init
class Encoder(nn.Module):
r"""
The `Encoder` layer of a variational autoencoder that encodes its input into a latent representation.
Args:
dims (`int` or `Tuple[int, int]`, *optional*, defaults to 3):
The number of dimensions to use in convolutions.
in_channels (`int`, *optional*, defaults to 3):
The number of input channels.
out_channels (`int`, *optional*, defaults to 3):
The number of output channels.
blocks (`List[Tuple[str, int]]`, *optional*, defaults to `[("res_x", 1)]`):
The blocks to use. Each block is a tuple of the block name and the number of layers.
base_channels (`int`, *optional*, defaults to 128):
The number of output channels for the first convolutional layer.
norm_num_groups (`int`, *optional*, defaults to 32):
The number of groups for normalization.
patch_size (`int`, *optional*, defaults to 1):
The patch size to use. Should be a power of 2.
norm_layer (`str`, *optional*, defaults to `group_norm`):
The normalization layer to use. Can be either `group_norm` or `pixel_norm`.
latent_log_var (`str`, *optional*, defaults to `per_channel`):
The number of channels for the log variance. Can be either `per_channel`, `uniform`, `constant` or `none`.
"""
def __init__(
self,
dims: Union[int, Tuple[int, int]] = 3,
in_channels: int = 3,
out_channels: int = 3,
blocks: List[Tuple[str, int | dict]] = [("res_x", 1)],
base_channels: int = 128,
norm_num_groups: int = 32,
patch_size: Union[int, Tuple[int]] = 1,
norm_layer: str = "group_norm", # group_norm, pixel_norm
latent_log_var: str = "per_channel",
spatial_padding_mode: str = "zeros",
):
super().__init__()
self.patch_size = patch_size
self.norm_layer = norm_layer
self.latent_channels = out_channels
self.latent_log_var = latent_log_var
self.blocks_desc = blocks
in_channels = in_channels * patch_size**2
output_channel = base_channels
self.conv_in = make_conv_nd(
dims=dims,
in_channels=in_channels,
out_channels=output_channel,
kernel_size=3,
stride=1,
padding=1,
causal=True,
spatial_padding_mode=spatial_padding_mode,
)
self.down_blocks = nn.ModuleList([])
for block_name, block_params in blocks:
input_channel = output_channel
if isinstance(block_params, int):
block_params = {"num_layers": block_params}
if block_name == "res_x":
block = UNetMidBlock3D(
dims=dims,
in_channels=input_channel,
num_layers=block_params["num_layers"],
resnet_eps=1e-6,
resnet_groups=norm_num_groups,
norm_layer=norm_layer,
spatial_padding_mode=spatial_padding_mode,
)
elif block_name == "res_x_y":
output_channel = block_params.get("multiplier", 2) * output_channel
block = ResnetBlock3D(
dims=dims,
in_channels=input_channel,
out_channels=output_channel,
eps=1e-6,
groups=norm_num_groups,
norm_layer=norm_layer,
spatial_padding_mode=spatial_padding_mode,
)
elif block_name == "compress_time":
block = make_conv_nd(
dims=dims,
in_channels=input_channel,
out_channels=output_channel,
kernel_size=3,
stride=(2, 1, 1),
causal=True,
spatial_padding_mode=spatial_padding_mode,
)
elif block_name == "compress_space":
block = make_conv_nd(
dims=dims,
in_channels=input_channel,
out_channels=output_channel,
kernel_size=3,
stride=(1, 2, 2),
causal=True,
spatial_padding_mode=spatial_padding_mode,
)
elif block_name == "compress_all":
block = make_conv_nd(
dims=dims,
in_channels=input_channel,
out_channels=output_channel,
kernel_size=3,
stride=(2, 2, 2),
causal=True,
spatial_padding_mode=spatial_padding_mode,
)
elif block_name == "compress_all_x_y":
output_channel = block_params.get("multiplier", 2) * output_channel
block = make_conv_nd(
dims=dims,
in_channels=input_channel,
out_channels=output_channel,
kernel_size=3,
stride=(2, 2, 2),
causal=True,
spatial_padding_mode=spatial_padding_mode,
)
elif block_name == "compress_all_res":
output_channel = block_params.get("multiplier", 2) * output_channel
block = SpaceToDepthDownsample(
dims=dims,
in_channels=input_channel,
out_channels=output_channel,
stride=(2, 2, 2),
spatial_padding_mode=spatial_padding_mode,
)
elif block_name == "compress_space_res":
output_channel = block_params.get("multiplier", 2) * output_channel
block = SpaceToDepthDownsample(
dims=dims,
in_channels=input_channel,
out_channels=output_channel,
stride=(1, 2, 2),
spatial_padding_mode=spatial_padding_mode,
)
elif block_name == "compress_time_res":
output_channel = block_params.get("multiplier", 2) * output_channel
block = SpaceToDepthDownsample(
dims=dims,
in_channels=input_channel,
out_channels=output_channel,
stride=(2, 1, 1),
spatial_padding_mode=spatial_padding_mode,
)
else:
raise ValueError(f"unknown block: {block_name}")
self.down_blocks.append(block)
# out
if norm_layer == "group_norm":
self.conv_norm_out = nn.GroupNorm(
num_channels=output_channel, num_groups=norm_num_groups, eps=1e-6
)
elif norm_layer == "pixel_norm":
self.conv_norm_out = PixelNorm()
elif norm_layer == "layer_norm":
self.conv_norm_out = LayerNorm(output_channel, eps=1e-6)
self.conv_act = nn.SiLU()
conv_out_channels = out_channels
if latent_log_var == "per_channel":
conv_out_channels *= 2
elif latent_log_var == "uniform":
conv_out_channels += 1
elif latent_log_var == "constant":
conv_out_channels += 1
elif latent_log_var != "none":
raise ValueError(f"Invalid latent_log_var: {latent_log_var}")
self.conv_out = make_conv_nd(
dims,
output_channel,
conv_out_channels,
3,
padding=1,
causal=True,
spatial_padding_mode=spatial_padding_mode,
)
self.gradient_checkpointing = False
def forward(self, sample: torch.FloatTensor) -> torch.FloatTensor:
r"""The forward method of the `Encoder` class."""
sample = patchify(sample, patch_size_hw=self.patch_size, patch_size_t=1)
sample = self.conv_in(sample)
checkpoint_fn = (
partial(torch.utils.checkpoint.checkpoint, use_reentrant=False)
if self.gradient_checkpointing and self.training
else lambda x: x
)
for down_block in self.down_blocks:
sample = checkpoint_fn(down_block)(sample)
sample = self.conv_norm_out(sample)
sample = self.conv_act(sample)
sample = self.conv_out(sample)
if self.latent_log_var == "uniform":
last_channel = sample[:, -1:, ...]
num_dims = sample.dim()
if num_dims == 4:
# For shape (B, C, H, W)
repeated_last_channel = last_channel.repeat(
1, sample.shape[1] - 2, 1, 1
)
sample = torch.cat([sample, repeated_last_channel], dim=1)
elif num_dims == 5:
# For shape (B, C, F, H, W)
repeated_last_channel = last_channel.repeat(
1, sample.shape[1] - 2, 1, 1, 1
)
sample = torch.cat([sample, repeated_last_channel], dim=1)
else:
raise ValueError(f"Invalid input shape: {sample.shape}")
elif self.latent_log_var == "constant":
sample = sample[:, :-1, ...]
approx_ln_0 = (
-30
) # this is the minimal clamp value in DiagonalGaussianDistribution objects
sample = torch.cat(
[sample, torch.ones_like(sample, device=sample.device) * approx_ln_0],
dim=1,
)
return sample
class Decoder(nn.Module):
r"""
The `Decoder` layer of a variational autoencoder that decodes its latent representation into an output sample.
Args:
dims (`int` or `Tuple[int, int]`, *optional*, defaults to 3):
The number of dimensions to use in convolutions.
in_channels (`int`, *optional*, defaults to 3):
The number of input channels.
out_channels (`int`, *optional*, defaults to 3):
The number of output channels.
blocks (`List[Tuple[str, int]]`, *optional*, defaults to `[("res_x", 1)]`):
The blocks to use. Each block is a tuple of the block name and the number of layers.
base_channels (`int`, *optional*, defaults to 128):
The number of output channels for the first convolutional layer.
norm_num_groups (`int`, *optional*, defaults to 32):
The number of groups for normalization.
patch_size (`int`, *optional*, defaults to 1):
The patch size to use. Should be a power of 2.
norm_layer (`str`, *optional*, defaults to `group_norm`):
The normalization layer to use. Can be either `group_norm` or `pixel_norm`.
causal (`bool`, *optional*, defaults to `True`):
Whether to use causal convolutions or not.
"""
def __init__(
self,
dims,
in_channels: int = 3,
out_channels: int = 3,
blocks: List[Tuple[str, int | dict]] = [("res_x", 1)],
base_channels: int = 128,
layers_per_block: int = 2,
norm_num_groups: int = 32,
patch_size: int = 1,
norm_layer: str = "group_norm",
causal: bool = True,
timestep_conditioning: bool = False,
spatial_padding_mode: str = "zeros",
):
super().__init__()
self.patch_size = patch_size
self.layers_per_block = layers_per_block
out_channels = out_channels * patch_size**2
self.causal = causal
self.blocks_desc = blocks
# Compute output channel to be product of all channel-multiplier blocks
output_channel = base_channels
for block_name, block_params in list(reversed(blocks)):
block_params = block_params if isinstance(block_params, dict) else {}
if block_name == "res_x_y":
output_channel = output_channel * block_params.get("multiplier", 2)
if block_name == "compress_all":
output_channel = output_channel * block_params.get("multiplier", 1)
self.conv_in = make_conv_nd(
dims,
in_channels,
output_channel,
kernel_size=3,
stride=1,
padding=1,
causal=True,
spatial_padding_mode=spatial_padding_mode,
)
self.up_blocks = nn.ModuleList([])
for block_name, block_params in list(reversed(blocks)):
input_channel = output_channel
if isinstance(block_params, int):
block_params = {"num_layers": block_params}
if block_name == "res_x":
block = UNetMidBlock3D(
dims=dims,
in_channels=input_channel,
num_layers=block_params["num_layers"],
resnet_eps=1e-6,
resnet_groups=norm_num_groups,
norm_layer=norm_layer,
inject_noise=block_params.get("inject_noise", False),
timestep_conditioning=timestep_conditioning,
spatial_padding_mode=spatial_padding_mode,
)
elif block_name == "attn_res_x":
block = UNetMidBlock3D(
dims=dims,
in_channels=input_channel,
num_layers=block_params["num_layers"],
resnet_groups=norm_num_groups,
norm_layer=norm_layer,
inject_noise=block_params.get("inject_noise", False),
timestep_conditioning=timestep_conditioning,
attention_head_dim=block_params["attention_head_dim"],
spatial_padding_mode=spatial_padding_mode,
)
elif block_name == "res_x_y":
output_channel = output_channel // block_params.get("multiplier", 2)
block = ResnetBlock3D(
dims=dims,
in_channels=input_channel,
out_channels=output_channel,
eps=1e-6,
groups=norm_num_groups,
norm_layer=norm_layer,
inject_noise=block_params.get("inject_noise", False),
timestep_conditioning=False,
spatial_padding_mode=spatial_padding_mode,
)
elif block_name == "compress_time":
block = DepthToSpaceUpsample(
dims=dims,
in_channels=input_channel,
stride=(2, 1, 1),
spatial_padding_mode=spatial_padding_mode,
)
elif block_name == "compress_space":
block = DepthToSpaceUpsample(
dims=dims,
in_channels=input_channel,
stride=(1, 2, 2),
spatial_padding_mode=spatial_padding_mode,
)
elif block_name == "compress_all":
output_channel = output_channel // block_params.get("multiplier", 1)
block = DepthToSpaceUpsample(
dims=dims,
in_channels=input_channel,
stride=(2, 2, 2),
residual=block_params.get("residual", False),
out_channels_reduction_factor=block_params.get("multiplier", 1),
spatial_padding_mode=spatial_padding_mode,
)
else:
raise ValueError(f"unknown layer: {block_name}")
self.up_blocks.append(block)
if norm_layer == "group_norm":
self.conv_norm_out = nn.GroupNorm(
num_channels=output_channel, num_groups=norm_num_groups, eps=1e-6
)
elif norm_layer == "pixel_norm":
self.conv_norm_out = PixelNorm()
elif norm_layer == "layer_norm":
self.conv_norm_out = LayerNorm(output_channel, eps=1e-6)
self.conv_act = nn.SiLU()
self.conv_out = make_conv_nd(
dims,
output_channel,
out_channels,
3,
padding=1,
causal=True,
spatial_padding_mode=spatial_padding_mode,
)
self.gradient_checkpointing = False
self.timestep_conditioning = timestep_conditioning
if timestep_conditioning:
self.timestep_scale_multiplier = nn.Parameter(
torch.tensor(1000.0, dtype=torch.float32)
)
self.last_time_embedder = PixArtAlphaCombinedTimestepSizeEmbeddings(
output_channel * 2, 0, operations=ops,
)
self.last_scale_shift_table = nn.Parameter(torch.empty(2, output_channel))
# def forward(self, sample: torch.FloatTensor, target_shape) -> torch.FloatTensor:
def forward(
self,
sample: torch.FloatTensor,
timestep: Optional[torch.Tensor] = None,
) -> torch.FloatTensor:
r"""The forward method of the `Decoder` class."""
batch_size = sample.shape[0]
sample = self.conv_in(sample, causal=self.causal)
checkpoint_fn = (
partial(torch.utils.checkpoint.checkpoint, use_reentrant=False)
if self.gradient_checkpointing and self.training
else lambda x: x
)
scaled_timestep = None
if self.timestep_conditioning:
assert (
timestep is not None
), "should pass timestep with timestep_conditioning=True"
scaled_timestep = timestep * self.timestep_scale_multiplier.to(dtype=sample.dtype, device=sample.device)
for up_block in self.up_blocks:
if self.timestep_conditioning and isinstance(up_block, UNetMidBlock3D):
sample = checkpoint_fn(up_block)(
sample, causal=self.causal, timestep=scaled_timestep
)
else:
sample = checkpoint_fn(up_block)(sample, causal=self.causal)
sample = self.conv_norm_out(sample)
if self.timestep_conditioning:
embedded_timestep = self.last_time_embedder(
timestep=scaled_timestep.flatten(),
resolution=None,
aspect_ratio=None,
batch_size=sample.shape[0],
hidden_dtype=sample.dtype,
)
embedded_timestep = embedded_timestep.view(
batch_size, embedded_timestep.shape[-1], 1, 1, 1
)
ada_values = self.last_scale_shift_table[
None, ..., None, None, None
].to(device=sample.device, dtype=sample.dtype) + embedded_timestep.reshape(
batch_size,
2,
-1,
embedded_timestep.shape[-3],
embedded_timestep.shape[-2],
embedded_timestep.shape[-1],
)
shift, scale = ada_values.unbind(dim=1)
sample = sample * (1 + scale) + shift
sample = self.conv_act(sample)
sample = self.conv_out(sample, causal=self.causal)
sample = unpatchify(sample, patch_size_hw=self.patch_size, patch_size_t=1)
return sample
class UNetMidBlock3D(nn.Module):
"""
A 3D UNet mid-block [`UNetMidBlock3D`] with multiple residual blocks.
Args:
in_channels (`int`): The number of input channels.
dropout (`float`, *optional*, defaults to 0.0): The dropout rate.
num_layers (`int`, *optional*, defaults to 1): The number of residual blocks.
resnet_eps (`float`, *optional*, 1e-6 ): The epsilon value for the resnet blocks.
resnet_groups (`int`, *optional*, defaults to 32):
The number of groups to use in the group normalization layers of the resnet blocks.
norm_layer (`str`, *optional*, defaults to `group_norm`):
The normalization layer to use. Can be either `group_norm` or `pixel_norm`.
inject_noise (`bool`, *optional*, defaults to `False`):
Whether to inject noise into the hidden states.
timestep_conditioning (`bool`, *optional*, defaults to `False`):
Whether to condition the hidden states on the timestep.
Returns:
`torch.FloatTensor`: The output of the last residual block, which is a tensor of shape `(batch_size,
in_channels, height, width)`.
"""
def __init__(
self,
dims: Union[int, Tuple[int, int]],
in_channels: int,
dropout: float = 0.0,
num_layers: int = 1,
resnet_eps: float = 1e-6,
resnet_groups: int = 32,
norm_layer: str = "group_norm",
inject_noise: bool = False,
timestep_conditioning: bool = False,
spatial_padding_mode: str = "zeros",
):
super().__init__()
resnet_groups = (
resnet_groups if resnet_groups is not None else min(in_channels // 4, 32)
)
self.timestep_conditioning = timestep_conditioning
if timestep_conditioning:
self.time_embedder = PixArtAlphaCombinedTimestepSizeEmbeddings(
in_channels * 4, 0, operations=ops,
)
self.res_blocks = nn.ModuleList(
[
ResnetBlock3D(
dims=dims,
in_channels=in_channels,
out_channels=in_channels,
eps=resnet_eps,
groups=resnet_groups,
dropout=dropout,
norm_layer=norm_layer,
inject_noise=inject_noise,
timestep_conditioning=timestep_conditioning,
spatial_padding_mode=spatial_padding_mode,
)
for _ in range(num_layers)
]
)
def forward(
self,
hidden_states: torch.FloatTensor,
causal: bool = True,
timestep: Optional[torch.Tensor] = None,
) -> torch.FloatTensor:
timestep_embed = None
if self.timestep_conditioning:
assert (
timestep is not None
), "should pass timestep with timestep_conditioning=True"
batch_size = hidden_states.shape[0]
timestep_embed = self.time_embedder(
timestep=timestep.flatten(),
resolution=None,
aspect_ratio=None,
batch_size=batch_size,
hidden_dtype=hidden_states.dtype,
)
timestep_embed = timestep_embed.view(
batch_size, timestep_embed.shape[-1], 1, 1, 1
)
for resnet in self.res_blocks:
hidden_states = resnet(hidden_states, causal=causal, timestep=timestep_embed)
return hidden_states
class SpaceToDepthDownsample(nn.Module):
def __init__(self, dims, in_channels, out_channels, stride, spatial_padding_mode):
super().__init__()
self.stride = stride
self.group_size = in_channels * math.prod(stride) // out_channels
self.conv = make_conv_nd(
dims=dims,
in_channels=in_channels,
out_channels=out_channels // math.prod(stride),
kernel_size=3,
stride=1,
causal=True,
spatial_padding_mode=spatial_padding_mode,
)
def forward(self, x, causal: bool = True):
if self.stride[0] == 2:
x = torch.cat(
[x[:, :, :1, :, :], x], dim=2
) # duplicate first frames for padding
# skip connection
x_in = rearrange(
x,
"b c (d p1) (h p2) (w p3) -> b (c p1 p2 p3) d h w",
p1=self.stride[0],
p2=self.stride[1],
p3=self.stride[2],
)
x_in = rearrange(x_in, "b (c g) d h w -> b c g d h w", g=self.group_size)
x_in = x_in.mean(dim=2)
# conv
x = self.conv(x, causal=causal)
x = rearrange(
x,
"b c (d p1) (h p2) (w p3) -> b (c p1 p2 p3) d h w",
p1=self.stride[0],
p2=self.stride[1],
p3=self.stride[2],
)
x = x + x_in
return x
class DepthToSpaceUpsample(nn.Module):
def __init__(
self,
dims,
in_channels,
stride,
residual=False,
out_channels_reduction_factor=1,
spatial_padding_mode="zeros",
):
super().__init__()
self.stride = stride
self.out_channels = (
math.prod(stride) * in_channels // out_channels_reduction_factor
)
self.conv = make_conv_nd(
dims=dims,
in_channels=in_channels,
out_channels=self.out_channels,
kernel_size=3,
stride=1,
causal=True,
spatial_padding_mode=spatial_padding_mode,
)
self.residual = residual
self.out_channels_reduction_factor = out_channels_reduction_factor
def forward(self, x, causal: bool = True, timestep: Optional[torch.Tensor] = None):
if self.residual:
# Reshape and duplicate the input to match the output shape
x_in = rearrange(
x,
"b (c p1 p2 p3) d h w -> b c (d p1) (h p2) (w p3)",
p1=self.stride[0],
p2=self.stride[1],
p3=self.stride[2],
)
num_repeat = math.prod(self.stride) // self.out_channels_reduction_factor
x_in = x_in.repeat(1, num_repeat, 1, 1, 1)
if self.stride[0] == 2:
x_in = x_in[:, :, 1:, :, :]
x = self.conv(x, causal=causal)
x = rearrange(
x,
"b (c p1 p2 p3) d h w -> b c (d p1) (h p2) (w p3)",
p1=self.stride[0],
p2=self.stride[1],
p3=self.stride[2],
)
if self.stride[0] == 2:
x = x[:, :, 1:, :, :]
if self.residual:
x = x + x_in
return x
class LayerNorm(nn.Module):
def __init__(self, dim, eps, elementwise_affine=True) -> None:
super().__init__()
self.norm = ops.LayerNorm(dim, eps=eps, elementwise_affine=elementwise_affine)
def forward(self, x):
x = rearrange(x, "b c d h w -> b d h w c")
x = self.norm(x)
x = rearrange(x, "b d h w c -> b c d h w")
return x
class ResnetBlock3D(nn.Module):
r"""
A Resnet block.
Parameters:
in_channels (`int`): The number of channels in the input.
out_channels (`int`, *optional*, default to be `None`):
The number of output channels for the first conv layer. If None, same as `in_channels`.
dropout (`float`, *optional*, defaults to `0.0`): The dropout probability to use.
groups (`int`, *optional*, default to `32`): The number of groups to use for the first normalization layer.
eps (`float`, *optional*, defaults to `1e-6`): The epsilon to use for the normalization.
"""
def __init__(
self,
dims: Union[int, Tuple[int, int]],
in_channels: int,
out_channels: Optional[int] = None,
dropout: float = 0.0,
groups: int = 32,
eps: float = 1e-6,
norm_layer: str = "group_norm",
inject_noise: bool = False,
timestep_conditioning: bool = False,
spatial_padding_mode: str = "zeros",
):
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.inject_noise = inject_noise
if norm_layer == "group_norm":
self.norm1 = nn.GroupNorm(
num_groups=groups, num_channels=in_channels, eps=eps, affine=True
)
elif norm_layer == "pixel_norm":
self.norm1 = PixelNorm()
elif norm_layer == "layer_norm":
self.norm1 = LayerNorm(in_channels, eps=eps, elementwise_affine=True)
self.non_linearity = nn.SiLU()
self.conv1 = make_conv_nd(
dims,
in_channels,
out_channels,
kernel_size=3,
stride=1,
padding=1,
causal=True,
spatial_padding_mode=spatial_padding_mode,
)
if inject_noise:
self.per_channel_scale1 = nn.Parameter(torch.zeros((in_channels, 1, 1)))
if norm_layer == "group_norm":
self.norm2 = nn.GroupNorm(
num_groups=groups, num_channels=out_channels, eps=eps, affine=True
)
elif norm_layer == "pixel_norm":
self.norm2 = PixelNorm()
elif norm_layer == "layer_norm":
self.norm2 = LayerNorm(out_channels, eps=eps, elementwise_affine=True)
self.dropout = torch.nn.Dropout(dropout)
self.conv2 = make_conv_nd(
dims,
out_channels,
out_channels,
kernel_size=3,
stride=1,
padding=1,
causal=True,
spatial_padding_mode=spatial_padding_mode,
)
if inject_noise:
self.per_channel_scale2 = nn.Parameter(torch.zeros((in_channels, 1, 1)))
self.conv_shortcut = (
make_linear_nd(
dims=dims, in_channels=in_channels, out_channels=out_channels
)
if in_channels != out_channels
else nn.Identity()
)
self.norm3 = (
LayerNorm(in_channels, eps=eps, elementwise_affine=True)
if in_channels != out_channels
else nn.Identity()
)
self.timestep_conditioning = timestep_conditioning
if timestep_conditioning:
self.scale_shift_table = nn.Parameter(
torch.randn(4, in_channels) / in_channels**0.5
)
def _feed_spatial_noise(
self, hidden_states: torch.FloatTensor, per_channel_scale: torch.FloatTensor
) -> torch.FloatTensor:
spatial_shape = hidden_states.shape[-2:]
device = hidden_states.device
dtype = hidden_states.dtype
# similar to the "explicit noise inputs" method in style-gan
spatial_noise = torch.randn(spatial_shape, device=device, dtype=dtype)[None]
scaled_noise = (spatial_noise * per_channel_scale)[None, :, None, ...]
hidden_states = hidden_states + scaled_noise
return hidden_states
def forward(
self,
input_tensor: torch.FloatTensor,
causal: bool = True,
timestep: Optional[torch.Tensor] = None,
) -> torch.FloatTensor:
hidden_states = input_tensor
batch_size = hidden_states.shape[0]
hidden_states = self.norm1(hidden_states)
if self.timestep_conditioning:
assert (
timestep is not None
), "should pass timestep with timestep_conditioning=True"
ada_values = self.scale_shift_table[
None, ..., None, None, None
].to(device=hidden_states.device, dtype=hidden_states.dtype) + timestep.reshape(
batch_size,
4,
-1,
timestep.shape[-3],
timestep.shape[-2],
timestep.shape[-1],
)
shift1, scale1, shift2, scale2 = ada_values.unbind(dim=1)
hidden_states = hidden_states * (1 + scale1) + shift1
hidden_states = self.non_linearity(hidden_states)
hidden_states = self.conv1(hidden_states, causal=causal)
if self.inject_noise:
hidden_states = self._feed_spatial_noise(
hidden_states, self.per_channel_scale1.to(device=hidden_states.device, dtype=hidden_states.dtype)
)
hidden_states = self.norm2(hidden_states)
if self.timestep_conditioning:
hidden_states = hidden_states * (1 + scale2) + shift2
hidden_states = self.non_linearity(hidden_states)
hidden_states = self.dropout(hidden_states)
hidden_states = self.conv2(hidden_states, causal=causal)
if self.inject_noise:
hidden_states = self._feed_spatial_noise(
hidden_states, self.per_channel_scale2.to(device=hidden_states.device, dtype=hidden_states.dtype)
)
input_tensor = self.norm3(input_tensor)
batch_size = input_tensor.shape[0]
input_tensor = self.conv_shortcut(input_tensor)
output_tensor = input_tensor + hidden_states
return output_tensor
def patchify(x, patch_size_hw, patch_size_t=1):
if patch_size_hw == 1 and patch_size_t == 1:
return x
if x.dim() == 4:
x = rearrange(
x, "b c (h q) (w r) -> b (c r q) h w", q=patch_size_hw, r=patch_size_hw
)
elif x.dim() == 5:
x = rearrange(
x,
"b c (f p) (h q) (w r) -> b (c p r q) f h w",
p=patch_size_t,
q=patch_size_hw,
r=patch_size_hw,
)
else:
raise ValueError(f"Invalid input shape: {x.shape}")
return x
def unpatchify(x, patch_size_hw, patch_size_t=1):
if patch_size_hw == 1 and patch_size_t == 1:
return x
if x.dim() == 4:
x = rearrange(
x, "b (c r q) h w -> b c (h q) (w r)", q=patch_size_hw, r=patch_size_hw
)
elif x.dim() == 5:
x = rearrange(
x,
"b (c p r q) f h w -> b c (f p) (h q) (w r)",
p=patch_size_t,
q=patch_size_hw,
r=patch_size_hw,
)
return x
class processor(nn.Module):
def __init__(self):
super().__init__()
self.register_buffer("std-of-means", torch.empty(128))
self.register_buffer("mean-of-means", torch.empty(128))
self.register_buffer("mean-of-stds", torch.empty(128))
self.register_buffer("mean-of-stds_over_std-of-means", torch.empty(128))
self.register_buffer("channel", torch.empty(128))
def un_normalize(self, x):
return (x * self.get_buffer("std-of-means").view(1, -1, 1, 1, 1).to(x)) + self.get_buffer("mean-of-means").view(1, -1, 1, 1, 1).to(x)
def normalize(self, x):
return (x - self.get_buffer("mean-of-means").view(1, -1, 1, 1, 1).to(x)) / self.get_buffer("std-of-means").view(1, -1, 1, 1, 1).to(x)
class VideoVAE(nn.Module):
def __init__(self, version=0, config=None):
super().__init__()
if config is None:
config = self.guess_config(version)
self.timestep_conditioning = config.get("timestep_conditioning", False)
double_z = config.get("double_z", True)
latent_log_var = config.get(
"latent_log_var", "per_channel" if double_z else "none"
)
self.encoder = Encoder(
dims=config["dims"],
in_channels=config.get("in_channels", 3),
out_channels=config["latent_channels"],
blocks=config.get("encoder_blocks", config.get("encoder_blocks", config.get("blocks"))),
patch_size=config.get("patch_size", 1),
latent_log_var=latent_log_var,
norm_layer=config.get("norm_layer", "group_norm"),
spatial_padding_mode=config.get("spatial_padding_mode", "zeros"),
)
self.decoder = Decoder(
dims=config["dims"],
in_channels=config["latent_channels"],
out_channels=config.get("out_channels", 3),
blocks=config.get("decoder_blocks", config.get("decoder_blocks", config.get("blocks"))),
patch_size=config.get("patch_size", 1),
norm_layer=config.get("norm_layer", "group_norm"),
causal=config.get("causal_decoder", False),
timestep_conditioning=self.timestep_conditioning,
spatial_padding_mode=config.get("spatial_padding_mode", "reflect"),
)
self.per_channel_statistics = processor()
def guess_config(self, version):
if version == 0:
config = {
"_class_name": "CausalVideoAutoencoder",
"dims": 3,
"in_channels": 3,
"out_channels": 3,
"latent_channels": 128,
"blocks": [
["res_x", 4],
["compress_all", 1],
["res_x_y", 1],
["res_x", 3],
["compress_all", 1],
["res_x_y", 1],
["res_x", 3],
["compress_all", 1],
["res_x", 3],
["res_x", 4],
],
"scaling_factor": 1.0,
"norm_layer": "pixel_norm",
"patch_size": 4,
"latent_log_var": "uniform",
"use_quant_conv": False,
"causal_decoder": False,
}
elif version == 1:
config = {
"_class_name": "CausalVideoAutoencoder",
"dims": 3,
"in_channels": 3,
"out_channels": 3,
"latent_channels": 128,
"decoder_blocks": [
["res_x", {"num_layers": 5, "inject_noise": True}],
["compress_all", {"residual": True, "multiplier": 2}],
["res_x", {"num_layers": 6, "inject_noise": True}],
["compress_all", {"residual": True, "multiplier": 2}],
["res_x", {"num_layers": 7, "inject_noise": True}],
["compress_all", {"residual": True, "multiplier": 2}],
["res_x", {"num_layers": 8, "inject_noise": False}]
],
"encoder_blocks": [
["res_x", {"num_layers": 4}],
["compress_all", {}],
["res_x_y", 1],
["res_x", {"num_layers": 3}],
["compress_all", {}],
["res_x_y", 1],
["res_x", {"num_layers": 3}],
["compress_all", {}],
["res_x", {"num_layers": 3}],
["res_x", {"num_layers": 4}]
],
"scaling_factor": 1.0,
"norm_layer": "pixel_norm",
"patch_size": 4,
"latent_log_var": "uniform",
"use_quant_conv": False,
"causal_decoder": False,
"timestep_conditioning": True,
}
else:
config = {
"_class_name": "CausalVideoAutoencoder",
"dims": 3,
"in_channels": 3,
"out_channels": 3,
"latent_channels": 128,
"encoder_blocks": [
["res_x", {"num_layers": 4}],
["compress_space_res", {"multiplier": 2}],
["res_x", {"num_layers": 6}],
["compress_time_res", {"multiplier": 2}],
["res_x", {"num_layers": 6}],
["compress_all_res", {"multiplier": 2}],
["res_x", {"num_layers": 2}],
["compress_all_res", {"multiplier": 2}],
["res_x", {"num_layers": 2}]
],
"decoder_blocks": [
["res_x", {"num_layers": 5, "inject_noise": False}],
["compress_all", {"residual": True, "multiplier": 2}],
["res_x", {"num_layers": 5, "inject_noise": False}],
["compress_all", {"residual": True, "multiplier": 2}],
["res_x", {"num_layers": 5, "inject_noise": False}],
["compress_all", {"residual": True, "multiplier": 2}],
["res_x", {"num_layers": 5, "inject_noise": False}]
],
"scaling_factor": 1.0,
"norm_layer": "pixel_norm",
"patch_size": 4,
"latent_log_var": "uniform",
"use_quant_conv": False,
"causal_decoder": False,
"timestep_conditioning": True
}
return config
def encode(self, x):
frames_count = x.shape[2]
if ((frames_count - 1) % 8) != 0:
raise ValueError("Invalid number of frames: Encode input must have 1 + 8 * x frames (e.g., 1, 9, 17, ...). Please check your input.")
means, logvar = torch.chunk(self.encoder(x), 2, dim=1)
return self.per_channel_statistics.normalize(means)
def decode(self, x, timestep=0.05, noise_scale=0.025):
if self.timestep_conditioning: #TODO: seed
x = torch.randn_like(x) * noise_scale + (1.0 - noise_scale) * x
return self.decoder(self.per_channel_statistics.un_normalize(x), timestep=timestep)
from typing import Tuple, Union
from .dual_conv3d import DualConv3d
from .causal_conv3d import CausalConv3d
import comfy.ops
ops = comfy.ops.disable_weight_init
def make_conv_nd(
dims: Union[int, Tuple[int, int]],
in_channels: int,
out_channels: int,
kernel_size: int,
stride=1,
padding=0,
dilation=1,
groups=1,
bias=True,
causal=False,
spatial_padding_mode="zeros",
temporal_padding_mode="zeros",
):
if not (spatial_padding_mode == temporal_padding_mode or causal):
raise NotImplementedError("spatial and temporal padding modes must be equal")
if dims == 2:
return ops.Conv2d(
in_channels=in_channels,
out_channels=out_channels,
kernel_size=kernel_size,
stride=stride,
padding=padding,
dilation=dilation,
groups=groups,
bias=bias,
padding_mode=spatial_padding_mode,
)
elif dims == 3:
if causal:
return CausalConv3d(
in_channels=in_channels,
out_channels=out_channels,
kernel_size=kernel_size,
stride=stride,
padding=padding,
dilation=dilation,
groups=groups,
bias=bias,
spatial_padding_mode=spatial_padding_mode,
)
return ops.Conv3d(
in_channels=in_channels,
out_channels=out_channels,
kernel_size=kernel_size,
stride=stride,
padding=padding,
dilation=dilation,
groups=groups,
bias=bias,
padding_mode=spatial_padding_mode,
)
elif dims == (2, 1):
return DualConv3d(
in_channels=in_channels,
out_channels=out_channels,
kernel_size=kernel_size,
stride=stride,
padding=padding,
bias=bias,
padding_mode=spatial_padding_mode,
)
else:
raise ValueError(f"unsupported dimensions: {dims}")
def make_linear_nd(
dims: int,
in_channels: int,
out_channels: int,
bias=True,
):
if dims == 2:
return ops.Conv2d(
in_channels=in_channels, out_channels=out_channels, kernel_size=1, bias=bias
)
elif dims == 3 or dims == (2, 1):
return ops.Conv3d(
in_channels=in_channels, out_channels=out_channels, kernel_size=1, bias=bias
)
else:
raise ValueError(f"unsupported dimensions: {dims}")
import math
from typing import Tuple, Union
import torch
import torch.nn as nn
import torch.nn.functional as F
from einops import rearrange
class DualConv3d(nn.Module):
def __init__(
self,
in_channels,
out_channels,
kernel_size,
stride: Union[int, Tuple[int, int, int]] = 1,
padding: Union[int, Tuple[int, int, int]] = 0,
dilation: Union[int, Tuple[int, int, int]] = 1,
groups=1,
bias=True,
padding_mode="zeros",
):
super(DualConv3d, self).__init__()
self.in_channels = in_channels
self.out_channels = out_channels
self.padding_mode = padding_mode
# Ensure kernel_size, stride, padding, and dilation are tuples of length 3
if isinstance(kernel_size, int):
kernel_size = (kernel_size, kernel_size, kernel_size)
if kernel_size == (1, 1, 1):
raise ValueError(
"kernel_size must be greater than 1. Use make_linear_nd instead."
)
if isinstance(stride, int):
stride = (stride, stride, stride)
if isinstance(padding, int):
padding = (padding, padding, padding)
if isinstance(dilation, int):
dilation = (dilation, dilation, dilation)
# Set parameters for convolutions
self.groups = groups
self.bias = bias
# Define the size of the channels after the first convolution
intermediate_channels = (
out_channels if in_channels < out_channels else in_channels
)
# Define parameters for the first convolution
self.weight1 = nn.Parameter(
torch.Tensor(
intermediate_channels,
in_channels // groups,
1,
kernel_size[1],
kernel_size[2],
)
)
self.stride1 = (1, stride[1], stride[2])
self.padding1 = (0, padding[1], padding[2])
self.dilation1 = (1, dilation[1], dilation[2])
if bias:
self.bias1 = nn.Parameter(torch.Tensor(intermediate_channels))
else:
self.register_parameter("bias1", None)
# Define parameters for the second convolution
self.weight2 = nn.Parameter(
torch.Tensor(
out_channels, intermediate_channels // groups, kernel_size[0], 1, 1
)
)
self.stride2 = (stride[0], 1, 1)
self.padding2 = (padding[0], 0, 0)
self.dilation2 = (dilation[0], 1, 1)
if bias:
self.bias2 = nn.Parameter(torch.Tensor(out_channels))
else:
self.register_parameter("bias2", None)
# Initialize weights and biases
self.reset_parameters()
def reset_parameters(self):
nn.init.kaiming_uniform_(self.weight1, a=math.sqrt(5))
nn.init.kaiming_uniform_(self.weight2, a=math.sqrt(5))
if self.bias:
fan_in1, _ = nn.init._calculate_fan_in_and_fan_out(self.weight1)
bound1 = 1 / math.sqrt(fan_in1)
nn.init.uniform_(self.bias1, -bound1, bound1)
fan_in2, _ = nn.init._calculate_fan_in_and_fan_out(self.weight2)
bound2 = 1 / math.sqrt(fan_in2)
nn.init.uniform_(self.bias2, -bound2, bound2)
def forward(self, x, use_conv3d=False, skip_time_conv=False):
if use_conv3d:
return self.forward_with_3d(x=x, skip_time_conv=skip_time_conv)
else:
return self.forward_with_2d(x=x, skip_time_conv=skip_time_conv)
def forward_with_3d(self, x, skip_time_conv):
# First convolution
x = F.conv3d(
x,
self.weight1,
self.bias1,
self.stride1,
self.padding1,
self.dilation1,
self.groups,
padding_mode=self.padding_mode,
)
if skip_time_conv:
return x
# Second convolution
x = F.conv3d(
x,
self.weight2,
self.bias2,
self.stride2,
self.padding2,
self.dilation2,
self.groups,
padding_mode=self.padding_mode,
)
return x
def forward_with_2d(self, x, skip_time_conv):
b, c, d, h, w = x.shape
# First 2D convolution
x = rearrange(x, "b c d h w -> (b d) c h w")
# Squeeze the depth dimension out of weight1 since it's 1
weight1 = self.weight1.squeeze(2)
# Select stride, padding, and dilation for the 2D convolution
stride1 = (self.stride1[1], self.stride1[2])
padding1 = (self.padding1[1], self.padding1[2])
dilation1 = (self.dilation1[1], self.dilation1[2])
x = F.conv2d(
x,
weight1,
self.bias1,
stride1,
padding1,
dilation1,
self.groups,
padding_mode=self.padding_mode,
)
_, _, h, w = x.shape
if skip_time_conv:
x = rearrange(x, "(b d) c h w -> b c d h w", b=b)
return x
# Second convolution which is essentially treated as a 1D convolution across the 'd' dimension
x = rearrange(x, "(b d) c h w -> (b h w) c d", b=b)
# Reshape weight2 to match the expected dimensions for conv1d
weight2 = self.weight2.squeeze(-1).squeeze(-1)
# Use only the relevant dimension for stride, padding, and dilation for the 1D convolution
stride2 = self.stride2[0]
padding2 = self.padding2[0]
dilation2 = self.dilation2[0]
x = F.conv1d(
x,
weight2,
self.bias2,
stride2,
padding2,
dilation2,
self.groups,
padding_mode=self.padding_mode,
)
x = rearrange(x, "(b h w) c d -> b c d h w", b=b, h=h, w=w)
return x
@property
def weight(self):
return self.weight2
def test_dual_conv3d_consistency():
# Initialize parameters
in_channels = 3
out_channels = 5
kernel_size = (3, 3, 3)
stride = (2, 2, 2)
padding = (1, 1, 1)
# Create an instance of the DualConv3d class
dual_conv3d = DualConv3d(
in_channels=in_channels,
out_channels=out_channels,
kernel_size=kernel_size,
stride=stride,
padding=padding,
bias=True,
)
# Example input tensor
test_input = torch.randn(1, 3, 10, 10, 10)
# Perform forward passes with both 3D and 2D settings
output_conv3d = dual_conv3d(test_input, use_conv3d=True)
output_2d = dual_conv3d(test_input, use_conv3d=False)
# Assert that the outputs from both methods are sufficiently close
assert torch.allclose(
output_conv3d, output_2d, atol=1e-6
), "Outputs are not consistent between 3D and 2D convolutions."
import torch
from torch import nn
class PixelNorm(nn.Module):
def __init__(self, dim=1, eps=1e-8):
super(PixelNorm, self).__init__()
self.dim = dim
self.eps = eps
def forward(self, x):
return x / torch.sqrt(torch.mean(x**2, dim=self.dim, keepdim=True) + self.eps)
# Code from: https://github.com/Alpha-VLLM/Lumina-Image-2.0/blob/main/models/model.py
from __future__ import annotations
from typing import List, Optional, Tuple
import torch
import torch.nn as nn
import torch.nn.functional as F
import comfy.ldm.common_dit
from comfy.ldm.modules.diffusionmodules.mmdit import TimestepEmbedder
from comfy.ldm.modules.attention import optimized_attention_masked
from comfy.ldm.flux.layers import EmbedND
import comfy.patcher_extension
def modulate(x, scale):
return x * (1 + scale.unsqueeze(1))
#############################################################################
# Core NextDiT Model #
#############################################################################
class JointAttention(nn.Module):
"""Multi-head attention module."""
def __init__(
self,
dim: int,
n_heads: int,
n_kv_heads: Optional[int],
qk_norm: bool,
operation_settings={},
):
"""
Initialize the Attention module.
Args:
dim (int): Number of input dimensions.
n_heads (int): Number of heads.
n_kv_heads (Optional[int]): Number of kv heads, if using GQA.
"""
super().__init__()
self.n_kv_heads = n_heads if n_kv_heads is None else n_kv_heads
self.n_local_heads = n_heads
self.n_local_kv_heads = self.n_kv_heads
self.n_rep = self.n_local_heads // self.n_local_kv_heads
self.head_dim = dim // n_heads
self.qkv = operation_settings.get("operations").Linear(
dim,
(n_heads + self.n_kv_heads + self.n_kv_heads) * self.head_dim,
bias=False,
device=operation_settings.get("device"),
dtype=operation_settings.get("dtype"),
)
self.out = operation_settings.get("operations").Linear(
n_heads * self.head_dim,
dim,
bias=False,
device=operation_settings.get("device"),
dtype=operation_settings.get("dtype"),
)
if qk_norm:
self.q_norm = operation_settings.get("operations").RMSNorm(self.head_dim, elementwise_affine=True, device=operation_settings.get("device"), dtype=operation_settings.get("dtype"))
self.k_norm = operation_settings.get("operations").RMSNorm(self.head_dim, elementwise_affine=True, device=operation_settings.get("device"), dtype=operation_settings.get("dtype"))
else:
self.q_norm = self.k_norm = nn.Identity()
@staticmethod
def apply_rotary_emb(
x_in: torch.Tensor,
freqs_cis: torch.Tensor,
) -> torch.Tensor:
"""
Apply rotary embeddings to input tensors using the given frequency
tensor.
This function applies rotary embeddings to the given query 'xq' and
key 'xk' tensors using the provided frequency tensor 'freqs_cis'. The
input tensors are reshaped as complex numbers, and the frequency tensor
is reshaped for broadcasting compatibility. The resulting tensors
contain rotary embeddings and are returned as real tensors.
Args:
x_in (torch.Tensor): Query or Key tensor to apply rotary embeddings.
freqs_cis (torch.Tensor): Precomputed frequency tensor for complex
exponentials.
Returns:
Tuple[torch.Tensor, torch.Tensor]: Tuple of modified query tensor
and key tensor with rotary embeddings.
"""
t_ = x_in.reshape(*x_in.shape[:-1], -1, 1, 2)
t_out = freqs_cis[..., 0] * t_[..., 0] + freqs_cis[..., 1] * t_[..., 1]
return t_out.reshape(*x_in.shape)
def forward(
self,
x: torch.Tensor,
x_mask: torch.Tensor,
freqs_cis: torch.Tensor,
) -> torch.Tensor:
"""
Args:
x:
x_mask:
freqs_cis:
Returns:
"""
bsz, seqlen, _ = x.shape
xq, xk, xv = torch.split(
self.qkv(x),
[
self.n_local_heads * self.head_dim,
self.n_local_kv_heads * self.head_dim,
self.n_local_kv_heads * self.head_dim,
],
dim=-1,
)
xq = xq.view(bsz, seqlen, self.n_local_heads, self.head_dim)
xk = xk.view(bsz, seqlen, self.n_local_kv_heads, self.head_dim)
xv = xv.view(bsz, seqlen, self.n_local_kv_heads, self.head_dim)
xq = self.q_norm(xq)
xk = self.k_norm(xk)
xq = JointAttention.apply_rotary_emb(xq, freqs_cis=freqs_cis)
xk = JointAttention.apply_rotary_emb(xk, freqs_cis=freqs_cis)
n_rep = self.n_local_heads // self.n_local_kv_heads
if n_rep >= 1:
xk = xk.unsqueeze(3).repeat(1, 1, 1, n_rep, 1).flatten(2, 3)
xv = xv.unsqueeze(3).repeat(1, 1, 1, n_rep, 1).flatten(2, 3)
output = optimized_attention_masked(xq.movedim(1, 2), xk.movedim(1, 2), xv.movedim(1, 2), self.n_local_heads, x_mask, skip_reshape=True)
return self.out(output)
class FeedForward(nn.Module):
def __init__(
self,
dim: int,
hidden_dim: int,
multiple_of: int,
ffn_dim_multiplier: Optional[float],
operation_settings={},
):
"""
Initialize the FeedForward module.
Args:
dim (int): Input dimension.
hidden_dim (int): Hidden dimension of the feedforward layer.
multiple_of (int): Value to ensure hidden dimension is a multiple
of this value.
ffn_dim_multiplier (float, optional): Custom multiplier for hidden
dimension. Defaults to None.
"""
super().__init__()
# custom dim factor multiplier
if ffn_dim_multiplier is not None:
hidden_dim = int(ffn_dim_multiplier * hidden_dim)
hidden_dim = multiple_of * ((hidden_dim + multiple_of - 1) // multiple_of)
self.w1 = operation_settings.get("operations").Linear(
dim,
hidden_dim,
bias=False,
device=operation_settings.get("device"),
dtype=operation_settings.get("dtype"),
)
self.w2 = operation_settings.get("operations").Linear(
hidden_dim,
dim,
bias=False,
device=operation_settings.get("device"),
dtype=operation_settings.get("dtype"),
)
self.w3 = operation_settings.get("operations").Linear(
dim,
hidden_dim,
bias=False,
device=operation_settings.get("device"),
dtype=operation_settings.get("dtype"),
)
# @torch.compile
def _forward_silu_gating(self, x1, x3):
return F.silu(x1) * x3
def forward(self, x):
return self.w2(self._forward_silu_gating(self.w1(x), self.w3(x)))
class JointTransformerBlock(nn.Module):
def __init__(
self,
layer_id: int,
dim: int,
n_heads: int,
n_kv_heads: int,
multiple_of: int,
ffn_dim_multiplier: float,
norm_eps: float,
qk_norm: bool,
modulation=True,
operation_settings={},
) -> None:
"""
Initialize a TransformerBlock.
Args:
layer_id (int): Identifier for the layer.
dim (int): Embedding dimension of the input features.
n_heads (int): Number of attention heads.
n_kv_heads (Optional[int]): Number of attention heads in key and
value features (if using GQA), or set to None for the same as
query.
multiple_of (int):
ffn_dim_multiplier (float):
norm_eps (float):
"""
super().__init__()
self.dim = dim
self.head_dim = dim // n_heads
self.attention = JointAttention(dim, n_heads, n_kv_heads, qk_norm, operation_settings=operation_settings)
self.feed_forward = FeedForward(
dim=dim,
hidden_dim=4 * dim,
multiple_of=multiple_of,
ffn_dim_multiplier=ffn_dim_multiplier,
operation_settings=operation_settings,
)
self.layer_id = layer_id
self.attention_norm1 = operation_settings.get("operations").RMSNorm(dim, eps=norm_eps, elementwise_affine=True, device=operation_settings.get("device"), dtype=operation_settings.get("dtype"))
self.ffn_norm1 = operation_settings.get("operations").RMSNorm(dim, eps=norm_eps, elementwise_affine=True, device=operation_settings.get("device"), dtype=operation_settings.get("dtype"))
self.attention_norm2 = operation_settings.get("operations").RMSNorm(dim, eps=norm_eps, elementwise_affine=True, device=operation_settings.get("device"), dtype=operation_settings.get("dtype"))
self.ffn_norm2 = operation_settings.get("operations").RMSNorm(dim, eps=norm_eps, elementwise_affine=True, device=operation_settings.get("device"), dtype=operation_settings.get("dtype"))
self.modulation = modulation
if modulation:
self.adaLN_modulation = nn.Sequential(
nn.SiLU(),
operation_settings.get("operations").Linear(
min(dim, 1024),
4 * dim,
bias=True,
device=operation_settings.get("device"),
dtype=operation_settings.get("dtype"),
),
)
def forward(
self,
x: torch.Tensor,
x_mask: torch.Tensor,
freqs_cis: torch.Tensor,
adaln_input: Optional[torch.Tensor]=None,
):
"""
Perform a forward pass through the TransformerBlock.
Args:
x (torch.Tensor): Input tensor.
freqs_cis (torch.Tensor): Precomputed cosine and sine frequencies.
Returns:
torch.Tensor: Output tensor after applying attention and
feedforward layers.
"""
if self.modulation:
assert adaln_input is not None
scale_msa, gate_msa, scale_mlp, gate_mlp = self.adaLN_modulation(adaln_input).chunk(4, dim=1)
x = x + gate_msa.unsqueeze(1).tanh() * self.attention_norm2(
self.attention(
modulate(self.attention_norm1(x), scale_msa),
x_mask,
freqs_cis,
)
)
x = x + gate_mlp.unsqueeze(1).tanh() * self.ffn_norm2(
self.feed_forward(
modulate(self.ffn_norm1(x), scale_mlp),
)
)
else:
assert adaln_input is None
x = x + self.attention_norm2(
self.attention(
self.attention_norm1(x),
x_mask,
freqs_cis,
)
)
x = x + self.ffn_norm2(
self.feed_forward(
self.ffn_norm1(x),
)
)
return x
class FinalLayer(nn.Module):
"""
The final layer of NextDiT.
"""
def __init__(self, hidden_size, patch_size, out_channels, operation_settings={}):
super().__init__()
self.norm_final = operation_settings.get("operations").LayerNorm(
hidden_size,
elementwise_affine=False,
eps=1e-6,
device=operation_settings.get("device"),
dtype=operation_settings.get("dtype"),
)
self.linear = operation_settings.get("operations").Linear(
hidden_size,
patch_size * patch_size * out_channels,
bias=True,
device=operation_settings.get("device"),
dtype=operation_settings.get("dtype"),
)
self.adaLN_modulation = nn.Sequential(
nn.SiLU(),
operation_settings.get("operations").Linear(
min(hidden_size, 1024),
hidden_size,
bias=True,
device=operation_settings.get("device"),
dtype=operation_settings.get("dtype"),
),
)
def forward(self, x, c):
scale = self.adaLN_modulation(c)
x = modulate(self.norm_final(x), scale)
x = self.linear(x)
return x
class NextDiT(nn.Module):
"""
Diffusion model with a Transformer backbone.
"""
def __init__(
self,
patch_size: int = 2,
in_channels: int = 4,
dim: int = 4096,
n_layers: int = 32,
n_refiner_layers: int = 2,
n_heads: int = 32,
n_kv_heads: Optional[int] = None,
multiple_of: int = 256,
ffn_dim_multiplier: Optional[float] = None,
norm_eps: float = 1e-5,
qk_norm: bool = False,
cap_feat_dim: int = 5120,
axes_dims: List[int] = (16, 56, 56),
axes_lens: List[int] = (1, 512, 512),
image_model=None,
device=None,
dtype=None,
operations=None,
) -> None:
super().__init__()
self.dtype = dtype
operation_settings = {"operations": operations, "device": device, "dtype": dtype}
self.in_channels = in_channels
self.out_channels = in_channels
self.patch_size = patch_size
self.x_embedder = operation_settings.get("operations").Linear(
in_features=patch_size * patch_size * in_channels,
out_features=dim,
bias=True,
device=operation_settings.get("device"),
dtype=operation_settings.get("dtype"),
)
self.noise_refiner = nn.ModuleList(
[
JointTransformerBlock(
layer_id,
dim,
n_heads,
n_kv_heads,
multiple_of,
ffn_dim_multiplier,
norm_eps,
qk_norm,
modulation=True,
operation_settings=operation_settings,
)
for layer_id in range(n_refiner_layers)
]
)
self.context_refiner = nn.ModuleList(
[
JointTransformerBlock(
layer_id,
dim,
n_heads,
n_kv_heads,
multiple_of,
ffn_dim_multiplier,
norm_eps,
qk_norm,
modulation=False,
operation_settings=operation_settings,
)
for layer_id in range(n_refiner_layers)
]
)
self.t_embedder = TimestepEmbedder(min(dim, 1024), **operation_settings)
self.cap_embedder = nn.Sequential(
operation_settings.get("operations").RMSNorm(cap_feat_dim, eps=norm_eps, elementwise_affine=True, device=operation_settings.get("device"), dtype=operation_settings.get("dtype")),
operation_settings.get("operations").Linear(
cap_feat_dim,
dim,
bias=True,
device=operation_settings.get("device"),
dtype=operation_settings.get("dtype"),
),
)
self.layers = nn.ModuleList(
[
JointTransformerBlock(
layer_id,
dim,
n_heads,
n_kv_heads,
multiple_of,
ffn_dim_multiplier,
norm_eps,
qk_norm,
operation_settings=operation_settings,
)
for layer_id in range(n_layers)
]
)
self.norm_final = operation_settings.get("operations").RMSNorm(dim, eps=norm_eps, elementwise_affine=True, device=operation_settings.get("device"), dtype=operation_settings.get("dtype"))
self.final_layer = FinalLayer(dim, patch_size, self.out_channels, operation_settings=operation_settings)
assert (dim // n_heads) == sum(axes_dims)
self.axes_dims = axes_dims
self.axes_lens = axes_lens
self.rope_embedder = EmbedND(dim=dim // n_heads, theta=10000.0, axes_dim=axes_dims)
self.dim = dim
self.n_heads = n_heads
def unpatchify(
self, x: torch.Tensor, img_size: List[Tuple[int, int]], cap_size: List[int], return_tensor=False
) -> List[torch.Tensor]:
"""
x: (N, T, patch_size**2 * C)
imgs: (N, H, W, C)
"""
pH = pW = self.patch_size
imgs = []
for i in range(x.size(0)):
H, W = img_size[i]
begin = cap_size[i]
end = begin + (H // pH) * (W // pW)
imgs.append(
x[i][begin:end]
.view(H // pH, W // pW, pH, pW, self.out_channels)
.permute(4, 0, 2, 1, 3)
.flatten(3, 4)
.flatten(1, 2)
)
if return_tensor:
imgs = torch.stack(imgs, dim=0)
return imgs
def patchify_and_embed(
self, x: List[torch.Tensor] | torch.Tensor, cap_feats: torch.Tensor, cap_mask: torch.Tensor, t: torch.Tensor, num_tokens
) -> Tuple[torch.Tensor, torch.Tensor, List[Tuple[int, int]], List[int], torch.Tensor]:
bsz = len(x)
pH = pW = self.patch_size
device = x[0].device
dtype = x[0].dtype
if cap_mask is not None:
l_effective_cap_len = cap_mask.sum(dim=1).tolist()
else:
l_effective_cap_len = [num_tokens] * bsz
if cap_mask is not None and not torch.is_floating_point(cap_mask):
cap_mask = (cap_mask - 1).to(dtype) * torch.finfo(dtype).max
img_sizes = [(img.size(1), img.size(2)) for img in x]
l_effective_img_len = [(H // pH) * (W // pW) for (H, W) in img_sizes]
max_seq_len = max(
(cap_len+img_len for cap_len, img_len in zip(l_effective_cap_len, l_effective_img_len))
)
max_cap_len = max(l_effective_cap_len)
max_img_len = max(l_effective_img_len)
position_ids = torch.zeros(bsz, max_seq_len, 3, dtype=torch.int32, device=device)
for i in range(bsz):
cap_len = l_effective_cap_len[i]
img_len = l_effective_img_len[i]
H, W = img_sizes[i]
H_tokens, W_tokens = H // pH, W // pW
assert H_tokens * W_tokens == img_len
position_ids[i, :cap_len, 0] = torch.arange(cap_len, dtype=torch.int32, device=device)
position_ids[i, cap_len:cap_len+img_len, 0] = cap_len
row_ids = torch.arange(H_tokens, dtype=torch.int32, device=device).view(-1, 1).repeat(1, W_tokens).flatten()
col_ids = torch.arange(W_tokens, dtype=torch.int32, device=device).view(1, -1).repeat(H_tokens, 1).flatten()
position_ids[i, cap_len:cap_len+img_len, 1] = row_ids
position_ids[i, cap_len:cap_len+img_len, 2] = col_ids
freqs_cis = self.rope_embedder(position_ids).movedim(1, 2).to(dtype)
# build freqs_cis for cap and image individually
cap_freqs_cis_shape = list(freqs_cis.shape)
# cap_freqs_cis_shape[1] = max_cap_len
cap_freqs_cis_shape[1] = cap_feats.shape[1]
cap_freqs_cis = torch.zeros(*cap_freqs_cis_shape, device=device, dtype=freqs_cis.dtype)
img_freqs_cis_shape = list(freqs_cis.shape)
img_freqs_cis_shape[1] = max_img_len
img_freqs_cis = torch.zeros(*img_freqs_cis_shape, device=device, dtype=freqs_cis.dtype)
for i in range(bsz):
cap_len = l_effective_cap_len[i]
img_len = l_effective_img_len[i]
cap_freqs_cis[i, :cap_len] = freqs_cis[i, :cap_len]
img_freqs_cis[i, :img_len] = freqs_cis[i, cap_len:cap_len+img_len]
# refine context
for layer in self.context_refiner:
cap_feats = layer(cap_feats, cap_mask, cap_freqs_cis)
# refine image
flat_x = []
for i in range(bsz):
img = x[i]
C, H, W = img.size()
img = img.view(C, H // pH, pH, W // pW, pW).permute(1, 3, 2, 4, 0).flatten(2).flatten(0, 1)
flat_x.append(img)
x = flat_x
padded_img_embed = torch.zeros(bsz, max_img_len, x[0].shape[-1], device=device, dtype=x[0].dtype)
padded_img_mask = torch.zeros(bsz, max_img_len, dtype=dtype, device=device)
for i in range(bsz):
padded_img_embed[i, :l_effective_img_len[i]] = x[i]
padded_img_mask[i, l_effective_img_len[i]:] = -torch.finfo(dtype).max
padded_img_embed = self.x_embedder(padded_img_embed)
padded_img_mask = padded_img_mask.unsqueeze(1)
for layer in self.noise_refiner:
padded_img_embed = layer(padded_img_embed, padded_img_mask, img_freqs_cis, t)
if cap_mask is not None:
mask = torch.zeros(bsz, max_seq_len, dtype=dtype, device=device)
mask[:, :max_cap_len] = cap_mask[:, :max_cap_len]
else:
mask = None
padded_full_embed = torch.zeros(bsz, max_seq_len, self.dim, device=device, dtype=x[0].dtype)
for i in range(bsz):
cap_len = l_effective_cap_len[i]
img_len = l_effective_img_len[i]
padded_full_embed[i, :cap_len] = cap_feats[i, :cap_len]
padded_full_embed[i, cap_len:cap_len+img_len] = padded_img_embed[i, :img_len]
return padded_full_embed, mask, img_sizes, l_effective_cap_len, freqs_cis
def forward(self, x, timesteps, context, num_tokens, attention_mask=None, **kwargs):
return comfy.patcher_extension.WrapperExecutor.new_class_executor(
self._forward,
self,
comfy.patcher_extension.get_all_wrappers(comfy.patcher_extension.WrappersMP.DIFFUSION_MODEL, kwargs.get("transformer_options", {}))
).execute(x, timesteps, context, num_tokens, attention_mask, **kwargs)
# def forward(self, x, t, cap_feats, cap_mask):
def _forward(self, x, timesteps, context, num_tokens, attention_mask=None, **kwargs):
t = 1.0 - timesteps
cap_feats = context
cap_mask = attention_mask
bs, c, h, w = x.shape
x = comfy.ldm.common_dit.pad_to_patch_size(x, (self.patch_size, self.patch_size))
"""
Forward pass of NextDiT.
t: (N,) tensor of diffusion timesteps
y: (N,) tensor of text tokens/features
"""
t = self.t_embedder(t, dtype=x.dtype) # (N, D)
adaln_input = t
cap_feats = self.cap_embedder(cap_feats) # (N, L, D) # todo check if able to batchify w.o. redundant compute
x_is_tensor = isinstance(x, torch.Tensor)
x, mask, img_size, cap_size, freqs_cis = self.patchify_and_embed(x, cap_feats, cap_mask, t, num_tokens)
freqs_cis = freqs_cis.to(x.device)
for layer in self.layers:
x = layer(x, mask, freqs_cis, adaln_input)
x = self.final_layer(x, adaln_input)
x = self.unpatchify(x, img_size, cap_size, return_tensor=x_is_tensor)[:,:,:h,:w]
return -x
import logging
import math
import torch
from contextlib import contextmanager
from typing import Any, Dict, Tuple, Union
from comfy.ldm.modules.distributions.distributions import DiagonalGaussianDistribution
from comfy.ldm.util import get_obj_from_str, instantiate_from_config
from comfy.ldm.modules.ema import LitEma
import comfy.ops
class DiagonalGaussianRegularizer(torch.nn.Module):
def __init__(self, sample: bool = False):
super().__init__()
self.sample = sample
def get_trainable_parameters(self) -> Any:
yield from ()
def forward(self, z: torch.Tensor) -> Tuple[torch.Tensor, dict]:
posterior = DiagonalGaussianDistribution(z)
if self.sample:
z = posterior.sample()
else:
z = posterior.mode()
return z, None
class AbstractAutoencoder(torch.nn.Module):
"""
This is the base class for all autoencoders, including image autoencoders, image autoencoders with discriminators,
unCLIP models, etc. Hence, it is fairly general, and specific features
(e.g. discriminator training, encoding, decoding) must be implemented in subclasses.
"""
def __init__(
self,
ema_decay: Union[None, float] = None,
monitor: Union[None, str] = None,
input_key: str = "jpg",
**kwargs,
):
super().__init__()
self.input_key = input_key
self.use_ema = ema_decay is not None
if monitor is not None:
self.monitor = monitor
if self.use_ema:
self.model_ema = LitEma(self, decay=ema_decay)
logging.info(f"Keeping EMAs of {len(list(self.model_ema.buffers()))}.")
def get_input(self, batch) -> Any:
raise NotImplementedError()
def on_train_batch_end(self, *args, **kwargs):
# for EMA computation
if self.use_ema:
self.model_ema(self)
@contextmanager
def ema_scope(self, context=None):
if self.use_ema:
self.model_ema.store(self.parameters())
self.model_ema.copy_to(self)
if context is not None:
logging.info(f"{context}: Switched to EMA weights")
try:
yield None
finally:
if self.use_ema:
self.model_ema.restore(self.parameters())
if context is not None:
logging.info(f"{context}: Restored training weights")
def encode(self, *args, **kwargs) -> torch.Tensor:
raise NotImplementedError("encode()-method of abstract base class called")
def decode(self, *args, **kwargs) -> torch.Tensor:
raise NotImplementedError("decode()-method of abstract base class called")
def instantiate_optimizer_from_config(self, params, lr, cfg):
logging.info(f"loading >>> {cfg['target']} <<< optimizer from config")
return get_obj_from_str(cfg["target"])(
params, lr=lr, **cfg.get("params", dict())
)
def configure_optimizers(self) -> Any:
raise NotImplementedError()
class AutoencodingEngine(AbstractAutoencoder):
"""
Base class for all image autoencoders that we train, like VQGAN or AutoencoderKL
(we also restore them explicitly as special cases for legacy reasons).
Regularizations such as KL or VQ are moved to the regularizer class.
"""
def __init__(
self,
*args,
encoder_config: Dict,
decoder_config: Dict,
regularizer_config: Dict,
**kwargs,
):
super().__init__(*args, **kwargs)
self.encoder: torch.nn.Module = instantiate_from_config(encoder_config)
self.decoder: torch.nn.Module = instantiate_from_config(decoder_config)
self.regularization = instantiate_from_config(
regularizer_config
)
def get_last_layer(self):
return self.decoder.get_last_layer()
def encode(
self,
x: torch.Tensor,
return_reg_log: bool = False,
unregularized: bool = False,
) -> Union[torch.Tensor, Tuple[torch.Tensor, dict]]:
z = self.encoder(x)
if unregularized:
return z, dict()
z, reg_log = self.regularization(z)
if return_reg_log:
return z, reg_log
return z
def decode(self, z: torch.Tensor, **kwargs) -> torch.Tensor:
x = self.decoder(z, **kwargs)
return x
def forward(
self, x: torch.Tensor, **additional_decode_kwargs
) -> Tuple[torch.Tensor, torch.Tensor, dict]:
z, reg_log = self.encode(x, return_reg_log=True)
dec = self.decode(z, **additional_decode_kwargs)
return z, dec, reg_log
class AutoencodingEngineLegacy(AutoencodingEngine):
def __init__(self, embed_dim: int, **kwargs):
self.max_batch_size = kwargs.pop("max_batch_size", None)
ddconfig = kwargs.pop("ddconfig")
super().__init__(
encoder_config={
"target": "comfy.ldm.modules.diffusionmodules.model.Encoder",
"params": ddconfig,
},
decoder_config={
"target": "comfy.ldm.modules.diffusionmodules.model.Decoder",
"params": ddconfig,
},
**kwargs,
)
if ddconfig.get("conv3d", False):
conv_op = comfy.ops.disable_weight_init.Conv3d
else:
conv_op = comfy.ops.disable_weight_init.Conv2d
self.quant_conv = conv_op(
(1 + ddconfig["double_z"]) * ddconfig["z_channels"],
(1 + ddconfig["double_z"]) * embed_dim,
1,
)
self.post_quant_conv = conv_op(embed_dim, ddconfig["z_channels"], 1)
self.embed_dim = embed_dim
def get_autoencoder_params(self) -> list:
params = super().get_autoencoder_params()
return params
def encode(
self, x: torch.Tensor, return_reg_log: bool = False
) -> Union[torch.Tensor, Tuple[torch.Tensor, dict]]:
if self.max_batch_size is None:
z = self.encoder(x)
z = self.quant_conv(z)
else:
N = x.shape[0]
bs = self.max_batch_size
n_batches = int(math.ceil(N / bs))
z = list()
for i_batch in range(n_batches):
z_batch = self.encoder(x[i_batch * bs : (i_batch + 1) * bs])
z_batch = self.quant_conv(z_batch)
z.append(z_batch)
z = torch.cat(z, 0)
z, reg_log = self.regularization(z)
if return_reg_log:
return z, reg_log
return z
def decode(self, z: torch.Tensor, **decoder_kwargs) -> torch.Tensor:
if self.max_batch_size is None:
dec = self.post_quant_conv(z)
dec = self.decoder(dec, **decoder_kwargs)
else:
N = z.shape[0]
bs = self.max_batch_size
n_batches = int(math.ceil(N / bs))
dec = list()
for i_batch in range(n_batches):
dec_batch = self.post_quant_conv(z[i_batch * bs : (i_batch + 1) * bs])
dec_batch = self.decoder(dec_batch, **decoder_kwargs)
dec.append(dec_batch)
dec = torch.cat(dec, 0)
return dec
class AutoencoderKL(AutoencodingEngineLegacy):
def __init__(self, **kwargs):
if "lossconfig" in kwargs:
kwargs["loss_config"] = kwargs.pop("lossconfig")
super().__init__(
regularizer_config={
"target": (
"comfy.ldm.models.autoencoder.DiagonalGaussianRegularizer"
)
},
**kwargs,
)
import math
import sys
import torch
import torch.nn.functional as F
from torch import nn, einsum
from einops import rearrange, repeat
from typing import Optional
import logging
from .diffusionmodules.util import AlphaBlender, timestep_embedding
from .sub_quadratic_attention import efficient_dot_product_attention
from comfy import model_management
if model_management.xformers_enabled():
import xformers
import xformers.ops
if model_management.sage_attention_enabled():
try:
from sageattention import sageattn
except ModuleNotFoundError as e:
if e.name == "sageattention":
logging.error(f"\n\nTo use the `--use-sage-attention` feature, the `sageattention` package must be installed first.\ncommand:\n\t{sys.executable} -m pip install sageattention")
else:
raise e
exit(-1)
if model_management.flash_attention_enabled():
try:
from flash_attn import flash_attn_func
except ModuleNotFoundError:
logging.error(f"\n\nTo use the `--use-flash-attention` feature, the `flash-attn` package must be installed first.\ncommand:\n\t{sys.executable} -m pip install flash-attn")
exit(-1)
from comfy.cli_args import args
import comfy.ops
ops = comfy.ops.disable_weight_init
FORCE_UPCAST_ATTENTION_DTYPE = model_management.force_upcast_attention_dtype()
def get_attn_precision(attn_precision, current_dtype):
if args.dont_upcast_attention:
return None
if FORCE_UPCAST_ATTENTION_DTYPE is not None and current_dtype in FORCE_UPCAST_ATTENTION_DTYPE:
return FORCE_UPCAST_ATTENTION_DTYPE[current_dtype]
return attn_precision
def exists(val):
return val is not None
def default(val, d):
if exists(val):
return val
return d
# feedforward
class GEGLU(nn.Module):
def __init__(self, dim_in, dim_out, dtype=None, device=None, operations=ops):
super().__init__()
self.proj = operations.Linear(dim_in, dim_out * 2, dtype=dtype, device=device)
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., dtype=None, device=None, operations=ops):
super().__init__()
inner_dim = int(dim * mult)
dim_out = default(dim_out, dim)
project_in = nn.Sequential(
operations.Linear(dim, inner_dim, dtype=dtype, device=device),
nn.GELU()
) if not glu else GEGLU(dim, inner_dim, dtype=dtype, device=device, operations=operations)
self.net = nn.Sequential(
project_in,
nn.Dropout(dropout),
operations.Linear(inner_dim, dim_out, dtype=dtype, device=device)
)
def forward(self, x):
return self.net(x)
def Normalize(in_channels, dtype=None, device=None):
return torch.nn.GroupNorm(num_groups=32, num_channels=in_channels, eps=1e-6, affine=True, dtype=dtype, device=device)
def attention_basic(q, k, v, heads, mask=None, attn_precision=None, skip_reshape=False, skip_output_reshape=False):
attn_precision = get_attn_precision(attn_precision, q.dtype)
if skip_reshape:
b, _, _, dim_head = q.shape
else:
b, _, dim_head = q.shape
dim_head //= heads
scale = dim_head ** -0.5
h = heads
if skip_reshape:
q, k, v = map(
lambda t: t.reshape(b * heads, -1, dim_head),
(q, k, v),
)
else:
q, k, v = map(
lambda t: t.unsqueeze(3)
.reshape(b, -1, heads, dim_head)
.permute(0, 2, 1, 3)
.reshape(b * heads, -1, dim_head)
.contiguous(),
(q, k, v),
)
# force cast to fp32 to avoid overflowing
if attn_precision == torch.float32:
sim = einsum('b i d, b j d -> b i j', q.float(), k.float()) * scale
else:
sim = einsum('b i d, b j d -> b i j', q, k) * scale
del q, k
if exists(mask):
if mask.dtype == torch.bool:
mask = rearrange(mask, 'b ... -> b (...)') #TODO: check if this bool part matches pytorch attention
max_neg_value = -torch.finfo(sim.dtype).max
mask = repeat(mask, 'b j -> (b h) () j', h=h)
sim.masked_fill_(~mask, max_neg_value)
else:
if len(mask.shape) == 2:
bs = 1
else:
bs = mask.shape[0]
mask = mask.reshape(bs, -1, mask.shape[-2], mask.shape[-1]).expand(b, heads, -1, -1).reshape(-1, mask.shape[-2], mask.shape[-1])
sim.add_(mask)
# attention, what we cannot get enough of
sim = sim.softmax(dim=-1)
out = einsum('b i j, b j d -> b i d', sim.to(v.dtype), v)
if skip_output_reshape:
out = (
out.unsqueeze(0)
.reshape(b, heads, -1, dim_head)
)
else:
out = (
out.unsqueeze(0)
.reshape(b, heads, -1, dim_head)
.permute(0, 2, 1, 3)
.reshape(b, -1, heads * dim_head)
)
return out
def attention_sub_quad(query, key, value, heads, mask=None, attn_precision=None, skip_reshape=False, skip_output_reshape=False):
attn_precision = get_attn_precision(attn_precision, query.dtype)
if skip_reshape:
b, _, _, dim_head = query.shape
else:
b, _, dim_head = query.shape
dim_head //= heads
if skip_reshape:
query = query.reshape(b * heads, -1, dim_head)
value = value.reshape(b * heads, -1, dim_head)
key = key.reshape(b * heads, -1, dim_head).movedim(1, 2)
else:
query = query.unsqueeze(3).reshape(b, -1, heads, dim_head).permute(0, 2, 1, 3).reshape(b * heads, -1, dim_head)
value = value.unsqueeze(3).reshape(b, -1, heads, dim_head).permute(0, 2, 1, 3).reshape(b * heads, -1, dim_head)
key = key.unsqueeze(3).reshape(b, -1, heads, dim_head).permute(0, 2, 3, 1).reshape(b * heads, dim_head, -1)
dtype = query.dtype
upcast_attention = attn_precision == torch.float32 and query.dtype != torch.float32
if upcast_attention:
bytes_per_token = torch.finfo(torch.float32).bits//8
else:
bytes_per_token = torch.finfo(query.dtype).bits//8
batch_x_heads, q_tokens, _ = query.shape
_, _, k_tokens = key.shape
mem_free_total, _ = model_management.get_free_memory(query.device, True)
kv_chunk_size_min = None
kv_chunk_size = None
query_chunk_size = None
for x in [4096, 2048, 1024, 512, 256]:
count = mem_free_total / (batch_x_heads * bytes_per_token * x * 4.0)
if count >= k_tokens:
kv_chunk_size = k_tokens
query_chunk_size = x
break
if query_chunk_size is None:
query_chunk_size = 512
if mask is not None:
if len(mask.shape) == 2:
bs = 1
else:
bs = mask.shape[0]
mask = mask.reshape(bs, -1, mask.shape[-2], mask.shape[-1]).expand(b, heads, -1, -1).reshape(-1, mask.shape[-2], mask.shape[-1])
hidden_states = efficient_dot_product_attention(
query,
key,
value,
query_chunk_size=query_chunk_size,
kv_chunk_size=kv_chunk_size,
kv_chunk_size_min=kv_chunk_size_min,
use_checkpoint=False,
upcast_attention=upcast_attention,
mask=mask,
)
hidden_states = hidden_states.to(dtype)
if skip_output_reshape:
hidden_states = hidden_states.unflatten(0, (-1, heads))
else:
hidden_states = hidden_states.unflatten(0, (-1, heads)).transpose(1,2).flatten(start_dim=2)
return hidden_states
def attention_split(q, k, v, heads, mask=None, attn_precision=None, skip_reshape=False, skip_output_reshape=False):
attn_precision = get_attn_precision(attn_precision, q.dtype)
if skip_reshape:
b, _, _, dim_head = q.shape
else:
b, _, dim_head = q.shape
dim_head //= heads
scale = dim_head ** -0.5
if skip_reshape:
q, k, v = map(
lambda t: t.reshape(b * heads, -1, dim_head),
(q, k, v),
)
else:
q, k, v = map(
lambda t: t.unsqueeze(3)
.reshape(b, -1, heads, dim_head)
.permute(0, 2, 1, 3)
.reshape(b * heads, -1, dim_head)
.contiguous(),
(q, k, v),
)
r1 = torch.zeros(q.shape[0], q.shape[1], v.shape[2], device=q.device, dtype=q.dtype)
mem_free_total = model_management.get_free_memory(q.device)
if attn_precision == torch.float32:
element_size = 4
upcast = True
else:
element_size = q.element_size()
upcast = False
gb = 1024 ** 3
tensor_size = q.shape[0] * q.shape[1] * k.shape[1] * element_size
modifier = 3
mem_required = tensor_size * modifier
steps = 1
if mem_required > mem_free_total:
steps = 2**(math.ceil(math.log(mem_required / mem_free_total, 2)))
# print(f"Expected tensor size:{tensor_size/gb:0.1f}GB, cuda free:{mem_free_cuda/gb:0.1f}GB "
# f"torch free:{mem_free_torch/gb:0.1f} total:{mem_free_total/gb:0.1f} steps:{steps}")
if steps > 64:
max_res = math.floor(math.sqrt(math.sqrt(mem_free_total / 2.5)) / 8) * 64
raise RuntimeError(f'Not enough memory, use lower resolution (max approx. {max_res}x{max_res}). '
f'Need: {mem_required/64/gb:0.1f}GB free, Have:{mem_free_total/gb:0.1f}GB free')
if mask is not None:
if len(mask.shape) == 2:
bs = 1
else:
bs = mask.shape[0]
mask = mask.reshape(bs, -1, mask.shape[-2], mask.shape[-1]).expand(b, heads, -1, -1).reshape(-1, mask.shape[-2], mask.shape[-1])
# print("steps", steps, mem_required, mem_free_total, modifier, q.element_size(), tensor_size)
first_op_done = False
cleared_cache = False
while True:
try:
slice_size = q.shape[1] // steps if (q.shape[1] % steps) == 0 else q.shape[1]
for i in range(0, q.shape[1], slice_size):
end = i + slice_size
if upcast:
with torch.autocast(enabled=False, device_type = 'cuda'):
s1 = einsum('b i d, b j d -> b i j', q[:, i:end].float(), k.float()) * scale
else:
s1 = einsum('b i d, b j d -> b i j', q[:, i:end], k) * scale
if mask is not None:
if len(mask.shape) == 2:
s1 += mask[i:end]
else:
if mask.shape[1] == 1:
s1 += mask
else:
s1 += mask[:, i:end]
s2 = s1.softmax(dim=-1).to(v.dtype)
del s1
first_op_done = True
r1[:, i:end] = einsum('b i j, b j d -> b i d', s2, v)
del s2
break
except model_management.OOM_EXCEPTION as e:
if first_op_done == False:
model_management.soft_empty_cache(True)
if cleared_cache == False:
cleared_cache = True
logging.warning("out of memory error, emptying cache and trying again")
continue
steps *= 2
if steps > 64:
raise e
logging.warning("out of memory error, increasing steps and trying again {}".format(steps))
else:
raise e
del q, k, v
if skip_output_reshape:
r1 = (
r1.unsqueeze(0)
.reshape(b, heads, -1, dim_head)
)
else:
r1 = (
r1.unsqueeze(0)
.reshape(b, heads, -1, dim_head)
.permute(0, 2, 1, 3)
.reshape(b, -1, heads * dim_head)
)
return r1
BROKEN_XFORMERS = False
try:
x_vers = xformers.__version__
# XFormers bug confirmed on all versions from 0.0.21 to 0.0.26 (q with bs bigger than 65535 gives CUDA error)
BROKEN_XFORMERS = x_vers.startswith("0.0.2") and not x_vers.startswith("0.0.20")
except:
pass
def attention_xformers(q, k, v, heads, mask=None, attn_precision=None, skip_reshape=False, skip_output_reshape=False):
b = q.shape[0]
dim_head = q.shape[-1]
# check to make sure xformers isn't broken
disabled_xformers = False
if BROKEN_XFORMERS:
if b * heads > 65535:
disabled_xformers = True
if not disabled_xformers:
if torch.jit.is_tracing() or torch.jit.is_scripting():
disabled_xformers = True
if disabled_xformers:
return attention_pytorch(q, k, v, heads, mask, skip_reshape=skip_reshape)
if skip_reshape:
# b h k d -> b k h d
q, k, v = map(
lambda t: t.permute(0, 2, 1, 3),
(q, k, v),
)
# actually do the reshaping
else:
dim_head //= heads
q, k, v = map(
lambda t: t.reshape(b, -1, heads, dim_head),
(q, k, v),
)
if mask is not None:
# add a singleton batch dimension
if mask.ndim == 2:
mask = mask.unsqueeze(0)
# add a singleton heads dimension
if mask.ndim == 3:
mask = mask.unsqueeze(1)
# pad to a multiple of 8
pad = 8 - mask.shape[-1] % 8
# the xformers docs says that it's allowed to have a mask of shape (1, Nq, Nk)
# but when using separated heads, the shape has to be (B, H, Nq, Nk)
# in flux, this matrix ends up being over 1GB
# here, we create a mask with the same batch/head size as the input mask (potentially singleton or full)
mask_out = torch.empty([mask.shape[0], mask.shape[1], q.shape[1], mask.shape[-1] + pad], dtype=q.dtype, device=q.device)
mask_out[..., :mask.shape[-1]] = mask
# doesn't this remove the padding again??
mask = mask_out[..., :mask.shape[-1]]
mask = mask.expand(b, heads, -1, -1)
out = xformers.ops.memory_efficient_attention(q, k, v, attn_bias=mask)
if skip_output_reshape:
out = out.permute(0, 2, 1, 3)
else:
out = (
out.reshape(b, -1, heads * dim_head)
)
return out
if model_management.is_nvidia(): #pytorch 2.3 and up seem to have this issue.
SDP_BATCH_LIMIT = 2**15
else:
#TODO: other GPUs ?
SDP_BATCH_LIMIT = 2**31
def attention_pytorch(q, k, v, heads, mask=None, attn_precision=None, skip_reshape=False, skip_output_reshape=False):
if skip_reshape:
b, _, _, dim_head = q.shape
else:
b, _, dim_head = q.shape
dim_head //= heads
q, k, v = map(
lambda t: t.view(b, -1, heads, dim_head).transpose(1, 2),
(q, k, v),
)
if mask is not None:
# add a batch dimension if there isn't already one
if mask.ndim == 2:
mask = mask.unsqueeze(0)
# add a heads dimension if there isn't already one
if mask.ndim == 3:
mask = mask.unsqueeze(1)
#print(f"####### PANN_DEBUG attention SIZE : q={q.shape}, k={k.shape}, v={v.shape}")
if SDP_BATCH_LIMIT >= b:
out = comfy.ops.scaled_dot_product_attention(q, k, v, attn_mask=mask, dropout_p=0.0, is_causal=False)
if not skip_output_reshape:
out = (
out.transpose(1, 2).reshape(b, -1, heads * dim_head)
)
else:
out = torch.empty((b, q.shape[2], heads * dim_head), dtype=q.dtype, layout=q.layout, device=q.device)
for i in range(0, b, SDP_BATCH_LIMIT):
m = mask
if mask is not None:
if mask.shape[0] > 1:
m = mask[i : i + SDP_BATCH_LIMIT]
out[i : i + SDP_BATCH_LIMIT] = comfy.ops.scaled_dot_product_attention(
q[i : i + SDP_BATCH_LIMIT],
k[i : i + SDP_BATCH_LIMIT],
v[i : i + SDP_BATCH_LIMIT],
attn_mask=m,
dropout_p=0.0, is_causal=False
).transpose(1, 2).reshape(-1, q.shape[2], heads * dim_head)
return out
def attention_sage(q, k, v, heads, mask=None, attn_precision=None, skip_reshape=False, skip_output_reshape=False):
if skip_reshape:
b, _, _, dim_head = q.shape
tensor_layout = "HND"
else:
b, _, dim_head = q.shape
dim_head //= heads
q, k, v = map(
lambda t: t.view(b, -1, heads, dim_head),
(q, k, v),
)
tensor_layout = "NHD"
if mask is not None:
# add a batch dimension if there isn't already one
if mask.ndim == 2:
mask = mask.unsqueeze(0)
# add a heads dimension if there isn't already one
if mask.ndim == 3:
mask = mask.unsqueeze(1)
try:
out = sageattn(q, k, v, attn_mask=mask, is_causal=False, tensor_layout=tensor_layout)
except Exception as e:
logging.error("Error running sage attention: {}, using pytorch attention instead.".format(e))
if tensor_layout == "NHD":
q, k, v = map(
lambda t: t.transpose(1, 2),
(q, k, v),
)
return attention_pytorch(q, k, v, heads, mask=mask, skip_reshape=True, skip_output_reshape=skip_output_reshape)
if tensor_layout == "HND":
if not skip_output_reshape:
out = (
out.transpose(1, 2).reshape(b, -1, heads * dim_head)
)
else:
if skip_output_reshape:
out = out.transpose(1, 2)
else:
out = out.reshape(b, -1, heads * dim_head)
return out
try:
@torch.library.custom_op("flash_attention::flash_attn", mutates_args=())
def flash_attn_wrapper(q: torch.Tensor, k: torch.Tensor, v: torch.Tensor,
dropout_p: float = 0.0, causal: bool = False) -> torch.Tensor:
return flash_attn_func(q, k, v, dropout_p=dropout_p, causal=causal)
@flash_attn_wrapper.register_fake
def flash_attn_fake(q, k, v, dropout_p=0.0, causal=False):
# Output shape is the same as q
return q.new_empty(q.shape)
except AttributeError as error:
FLASH_ATTN_ERROR = error
def flash_attn_wrapper(q: torch.Tensor, k: torch.Tensor, v: torch.Tensor,
dropout_p: float = 0.0, causal: bool = False) -> torch.Tensor:
assert False, f"Could not define flash_attn_wrapper: {FLASH_ATTN_ERROR}"
def attention_flash(q, k, v, heads, mask=None, attn_precision=None, skip_reshape=False, skip_output_reshape=False):
if skip_reshape:
b, _, _, dim_head = q.shape
else:
b, _, dim_head = q.shape
dim_head //= heads
q, k, v = map(
lambda t: t.view(b, -1, heads, dim_head).transpose(1, 2),
(q, k, v),
)
if mask is not None:
# add a batch dimension if there isn't already one
if mask.ndim == 2:
mask = mask.unsqueeze(0)
# add a heads dimension if there isn't already one
if mask.ndim == 3:
mask = mask.unsqueeze(1)
try:
assert mask is None
out = flash_attn_wrapper(
q.transpose(1, 2),
k.transpose(1, 2),
v.transpose(1, 2),
dropout_p=0.0,
causal=False,
).transpose(1, 2)
except Exception as e:
logging.warning(f"Flash Attention failed, using default SDPA: {e}")
out = torch.nn.functional.scaled_dot_product_attention(q, k, v, attn_mask=mask, dropout_p=0.0, is_causal=False)
if not skip_output_reshape:
out = (
out.transpose(1, 2).reshape(b, -1, heads * dim_head)
)
return out
optimized_attention = attention_basic
if model_management.sage_attention_enabled():
logging.info("Using sage attention")
optimized_attention = attention_sage
elif model_management.xformers_enabled():
logging.info("Using xformers attention")
optimized_attention = attention_xformers
elif model_management.flash_attention_enabled():
logging.info("Using Flash Attention")
optimized_attention = attention_flash
elif model_management.pytorch_attention_enabled():
logging.info("Using pytorch attention")
optimized_attention = attention_pytorch
else:
if args.use_split_cross_attention:
logging.info("Using split optimization for attention")
optimized_attention = attention_split
else:
logging.info("Using sub quadratic optimization for attention, if you have memory or speed issues try using: --use-split-cross-attention")
optimized_attention = attention_sub_quad
optimized_attention_masked = optimized_attention
def optimized_attention_for_device(device, mask=False, small_input=False):
if small_input:
if model_management.pytorch_attention_enabled():
return attention_pytorch #TODO: need to confirm but this is probably slightly faster for small inputs in all cases
else:
return attention_basic
if device == torch.device("cpu"):
return attention_sub_quad
if mask:
return optimized_attention_masked
return optimized_attention
class CrossAttention(nn.Module):
def __init__(self, query_dim, context_dim=None, heads=8, dim_head=64, dropout=0., attn_precision=None, dtype=None, device=None, operations=ops):
super().__init__()
inner_dim = dim_head * heads
context_dim = default(context_dim, query_dim)
self.attn_precision = attn_precision
self.heads = heads
self.dim_head = dim_head
self.to_q = operations.Linear(query_dim, inner_dim, bias=False, dtype=dtype, device=device)
self.to_k = operations.Linear(context_dim, inner_dim, bias=False, dtype=dtype, device=device)
self.to_v = operations.Linear(context_dim, inner_dim, bias=False, dtype=dtype, device=device)
self.to_out = nn.Sequential(operations.Linear(inner_dim, query_dim, dtype=dtype, device=device), nn.Dropout(dropout))
def forward(self, x, context=None, value=None, mask=None):
q = self.to_q(x)
context = default(context, x)
k = self.to_k(context)
if value is not None:
v = self.to_v(value)
del value
else:
v = self.to_v(context)
if mask is None:
out = optimized_attention(q, k, v, self.heads, attn_precision=self.attn_precision)
else:
out = optimized_attention_masked(q, k, v, self.heads, mask, attn_precision=self.attn_precision)
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, ff_in=False, inner_dim=None,
disable_self_attn=False, disable_temporal_crossattention=False, switch_temporal_ca_to_sa=False, attn_precision=None, dtype=None, device=None, operations=ops):
super().__init__()
self.ff_in = ff_in or inner_dim is not None
if inner_dim is None:
inner_dim = dim
self.is_res = inner_dim == dim
self.attn_precision = attn_precision
if self.ff_in:
self.norm_in = operations.LayerNorm(dim, dtype=dtype, device=device)
self.ff_in = FeedForward(dim, dim_out=inner_dim, dropout=dropout, glu=gated_ff, dtype=dtype, device=device, operations=operations)
self.disable_self_attn = disable_self_attn
self.attn1 = CrossAttention(query_dim=inner_dim, heads=n_heads, dim_head=d_head, dropout=dropout,
context_dim=context_dim if self.disable_self_attn else None, attn_precision=self.attn_precision, dtype=dtype, device=device, operations=operations) # is a self-attention if not self.disable_self_attn
self.ff = FeedForward(inner_dim, dim_out=dim, dropout=dropout, glu=gated_ff, dtype=dtype, device=device, operations=operations)
if disable_temporal_crossattention:
if switch_temporal_ca_to_sa:
raise ValueError
else:
self.attn2 = None
else:
context_dim_attn2 = None
if not switch_temporal_ca_to_sa:
context_dim_attn2 = context_dim
self.attn2 = CrossAttention(query_dim=inner_dim, context_dim=context_dim_attn2,
heads=n_heads, dim_head=d_head, dropout=dropout, attn_precision=self.attn_precision, dtype=dtype, device=device, operations=operations) # is self-attn if context is none
self.norm2 = operations.LayerNorm(inner_dim, dtype=dtype, device=device)
self.norm1 = operations.LayerNorm(inner_dim, dtype=dtype, device=device)
self.norm3 = operations.LayerNorm(inner_dim, dtype=dtype, device=device)
self.n_heads = n_heads
self.d_head = d_head
self.switch_temporal_ca_to_sa = switch_temporal_ca_to_sa
def forward(self, x, context=None, transformer_options={}):
extra_options = {}
block = transformer_options.get("block", None)
block_index = transformer_options.get("block_index", 0)
transformer_patches = {}
transformer_patches_replace = {}
for k in transformer_options:
if k == "patches":
transformer_patches = transformer_options[k]
elif k == "patches_replace":
transformer_patches_replace = transformer_options[k]
else:
extra_options[k] = transformer_options[k]
extra_options["n_heads"] = self.n_heads
extra_options["dim_head"] = self.d_head
extra_options["attn_precision"] = self.attn_precision
if self.ff_in:
x_skip = x
x = self.ff_in(self.norm_in(x))
if self.is_res:
x += x_skip
n = self.norm1(x)
if self.disable_self_attn:
context_attn1 = context
else:
context_attn1 = None
value_attn1 = None
if "attn1_patch" in transformer_patches:
patch = transformer_patches["attn1_patch"]
if context_attn1 is None:
context_attn1 = n
value_attn1 = context_attn1
for p in patch:
n, context_attn1, value_attn1 = p(n, context_attn1, value_attn1, extra_options)
if block is not None:
transformer_block = (block[0], block[1], block_index)
else:
transformer_block = None
attn1_replace_patch = transformer_patches_replace.get("attn1", {})
block_attn1 = transformer_block
if block_attn1 not in attn1_replace_patch:
block_attn1 = block
if block_attn1 in attn1_replace_patch:
if context_attn1 is None:
context_attn1 = n
value_attn1 = n
n = self.attn1.to_q(n)
context_attn1 = self.attn1.to_k(context_attn1)
value_attn1 = self.attn1.to_v(value_attn1)
n = attn1_replace_patch[block_attn1](n, context_attn1, value_attn1, extra_options)
n = self.attn1.to_out(n)
else:
n = self.attn1(n, context=context_attn1, value=value_attn1)
if "attn1_output_patch" in transformer_patches:
patch = transformer_patches["attn1_output_patch"]
for p in patch:
n = p(n, extra_options)
x = n + x
if "middle_patch" in transformer_patches:
patch = transformer_patches["middle_patch"]
for p in patch:
x = p(x, extra_options)
if self.attn2 is not None:
n = self.norm2(x)
if self.switch_temporal_ca_to_sa:
context_attn2 = n
else:
context_attn2 = context
value_attn2 = None
if "attn2_patch" in transformer_patches:
patch = transformer_patches["attn2_patch"]
value_attn2 = context_attn2
for p in patch:
n, context_attn2, value_attn2 = p(n, context_attn2, value_attn2, extra_options)
attn2_replace_patch = transformer_patches_replace.get("attn2", {})
block_attn2 = transformer_block
if block_attn2 not in attn2_replace_patch:
block_attn2 = block
if block_attn2 in attn2_replace_patch:
if value_attn2 is None:
value_attn2 = context_attn2
n = self.attn2.to_q(n)
context_attn2 = self.attn2.to_k(context_attn2)
value_attn2 = self.attn2.to_v(value_attn2)
n = attn2_replace_patch[block_attn2](n, context_attn2, value_attn2, extra_options)
n = self.attn2.to_out(n)
else:
n = self.attn2(n, context=context_attn2, value=value_attn2)
if "attn2_output_patch" in transformer_patches:
patch = transformer_patches["attn2_output_patch"]
for p in patch:
n = p(n, extra_options)
x = n + x
if self.is_res:
x_skip = x
x = self.ff(self.norm3(x))
if self.is_res:
x = x_skip + x
return x
class SpatialTransformer(nn.Module):
"""
Transformer block for image-like data.
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,
disable_self_attn=False, use_linear=False,
use_checkpoint=True, attn_precision=None, dtype=None, device=None, operations=ops):
super().__init__()
if exists(context_dim) and not isinstance(context_dim, list):
context_dim = [context_dim] * depth
self.in_channels = in_channels
inner_dim = n_heads * d_head
self.norm = operations.GroupNorm(num_groups=32, num_channels=in_channels, eps=1e-6, affine=True, dtype=dtype, device=device)
if not use_linear:
self.proj_in = operations.Conv2d(in_channels,
inner_dim,
kernel_size=1,
stride=1,
padding=0, dtype=dtype, device=device)
else:
self.proj_in = operations.Linear(in_channels, inner_dim, dtype=dtype, device=device)
self.transformer_blocks = nn.ModuleList(
[BasicTransformerBlock(inner_dim, n_heads, d_head, dropout=dropout, context_dim=context_dim[d],
disable_self_attn=disable_self_attn, checkpoint=use_checkpoint, attn_precision=attn_precision, dtype=dtype, device=device, operations=operations)
for d in range(depth)]
)
if not use_linear:
self.proj_out = operations.Conv2d(inner_dim,in_channels,
kernel_size=1,
stride=1,
padding=0, dtype=dtype, device=device)
else:
self.proj_out = operations.Linear(in_channels, inner_dim, dtype=dtype, device=device)
self.use_linear = use_linear
def forward(self, x, context=None, transformer_options={}):
# note: if no context is given, cross-attention defaults to self-attention
if not isinstance(context, list):
context = [context] * len(self.transformer_blocks)
b, c, h, w = x.shape
transformer_options["activations_shape"] = list(x.shape)
x_in = x
x = self.norm(x)
if not self.use_linear:
x = self.proj_in(x)
x = x.movedim(1, 3).flatten(1, 2).contiguous()
if self.use_linear:
x = self.proj_in(x)
for i, block in enumerate(self.transformer_blocks):
transformer_options["block_index"] = i
x = block(x, context=context[i], transformer_options=transformer_options)
if self.use_linear:
x = self.proj_out(x)
x = x.reshape(x.shape[0], h, w, x.shape[-1]).movedim(3, 1).contiguous()
if not self.use_linear:
x = self.proj_out(x)
return x + x_in
class SpatialVideoTransformer(SpatialTransformer):
def __init__(
self,
in_channels,
n_heads,
d_head,
depth=1,
dropout=0.0,
use_linear=False,
context_dim=None,
use_spatial_context=False,
timesteps=None,
merge_strategy: str = "fixed",
merge_factor: float = 0.5,
time_context_dim=None,
ff_in=False,
checkpoint=False,
time_depth=1,
disable_self_attn=False,
disable_temporal_crossattention=False,
max_time_embed_period: int = 10000,
attn_precision=None,
dtype=None, device=None, operations=ops
):
super().__init__(
in_channels,
n_heads,
d_head,
depth=depth,
dropout=dropout,
use_checkpoint=checkpoint,
context_dim=context_dim,
use_linear=use_linear,
disable_self_attn=disable_self_attn,
attn_precision=attn_precision,
dtype=dtype, device=device, operations=operations
)
self.time_depth = time_depth
self.depth = depth
self.max_time_embed_period = max_time_embed_period
time_mix_d_head = d_head
n_time_mix_heads = n_heads
time_mix_inner_dim = int(time_mix_d_head * n_time_mix_heads)
inner_dim = n_heads * d_head
if use_spatial_context:
time_context_dim = context_dim
self.time_stack = nn.ModuleList(
[
BasicTransformerBlock(
inner_dim,
n_time_mix_heads,
time_mix_d_head,
dropout=dropout,
context_dim=time_context_dim,
# timesteps=timesteps,
checkpoint=checkpoint,
ff_in=ff_in,
inner_dim=time_mix_inner_dim,
disable_self_attn=disable_self_attn,
disable_temporal_crossattention=disable_temporal_crossattention,
attn_precision=attn_precision,
dtype=dtype, device=device, operations=operations
)
for _ in range(self.depth)
]
)
assert len(self.time_stack) == len(self.transformer_blocks)
self.use_spatial_context = use_spatial_context
self.in_channels = in_channels
time_embed_dim = self.in_channels * 4
self.time_pos_embed = nn.Sequential(
operations.Linear(self.in_channels, time_embed_dim, dtype=dtype, device=device),
nn.SiLU(),
operations.Linear(time_embed_dim, self.in_channels, dtype=dtype, device=device),
)
self.time_mixer = AlphaBlender(
alpha=merge_factor, merge_strategy=merge_strategy
)
def forward(
self,
x: torch.Tensor,
context: Optional[torch.Tensor] = None,
time_context: Optional[torch.Tensor] = None,
timesteps: Optional[int] = None,
image_only_indicator: Optional[torch.Tensor] = None,
transformer_options={}
) -> torch.Tensor:
_, _, h, w = x.shape
transformer_options["activations_shape"] = list(x.shape)
x_in = x
spatial_context = None
if exists(context):
spatial_context = context
if self.use_spatial_context:
assert (
context.ndim == 3
), f"n dims of spatial context should be 3 but are {context.ndim}"
if time_context is None:
time_context = context
time_context_first_timestep = time_context[::timesteps]
time_context = repeat(
time_context_first_timestep, "b ... -> (b n) ...", n=h * w
)
elif time_context is not None and not self.use_spatial_context:
time_context = repeat(time_context, "b ... -> (b n) ...", n=h * w)
if time_context.ndim == 2:
time_context = rearrange(time_context, "b c -> b 1 c")
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")
if self.use_linear:
x = self.proj_in(x)
num_frames = torch.arange(timesteps, device=x.device)
num_frames = repeat(num_frames, "t -> b t", b=x.shape[0] // timesteps)
num_frames = rearrange(num_frames, "b t -> (b t)")
t_emb = timestep_embedding(num_frames, self.in_channels, repeat_only=False, max_period=self.max_time_embed_period).to(x.dtype)
emb = self.time_pos_embed(t_emb)
emb = emb[:, None, :]
for it_, (block, mix_block) in enumerate(
zip(self.transformer_blocks, self.time_stack)
):
transformer_options["block_index"] = it_
x = block(
x,
context=spatial_context,
transformer_options=transformer_options,
)
x_mix = x
x_mix = x_mix + emb
B, S, C = x_mix.shape
x_mix = rearrange(x_mix, "(b t) s c -> (b s) t c", t=timesteps)
x_mix = mix_block(x_mix, context=time_context) #TODO: transformer_options
x_mix = rearrange(
x_mix, "(b s) t c -> (b t) s c", s=S, b=B // timesteps, c=C, t=timesteps
)
x = self.time_mixer(x_spatial=x, x_temporal=x_mix, image_only_indicator=image_only_indicator)
if self.use_linear:
x = self.proj_out(x)
x = rearrange(x, "b (h w) c -> b c h w", h=h, w=w)
if not self.use_linear:
x = self.proj_out(x)
out = x + x_in
return out
from functools import partial
from typing import Dict, Optional, List
import numpy as np
import torch
import torch.nn as nn
from ..attention import optimized_attention
from einops import rearrange, repeat
from .util import timestep_embedding
import comfy.ops
import comfy.ldm.common_dit
def default(x, y):
if x is not None:
return x
return y
class Mlp(nn.Module):
""" MLP as used in Vision Transformer, MLP-Mixer and related networks
"""
def __init__(
self,
in_features,
hidden_features=None,
out_features=None,
act_layer=nn.GELU,
norm_layer=None,
bias=True,
drop=0.,
use_conv=False,
dtype=None,
device=None,
operations=None,
):
super().__init__()
out_features = out_features or in_features
hidden_features = hidden_features or in_features
drop_probs = drop
linear_layer = partial(operations.Conv2d, kernel_size=1) if use_conv else operations.Linear
self.fc1 = linear_layer(in_features, hidden_features, bias=bias, dtype=dtype, device=device)
self.act = act_layer()
self.drop1 = nn.Dropout(drop_probs)
self.norm = norm_layer(hidden_features) if norm_layer is not None else nn.Identity()
self.fc2 = linear_layer(hidden_features, out_features, bias=bias, dtype=dtype, device=device)
self.drop2 = nn.Dropout(drop_probs)
def forward(self, x):
x = self.fc1(x)
x = self.act(x)
x = self.drop1(x)
x = self.norm(x)
x = self.fc2(x)
x = self.drop2(x)
return x
class PatchEmbed(nn.Module):
""" 2D Image to Patch Embedding
"""
dynamic_img_pad: torch.jit.Final[bool]
def __init__(
self,
img_size: Optional[int] = 224,
patch_size: int = 16,
in_chans: int = 3,
embed_dim: int = 768,
norm_layer = None,
flatten: bool = True,
bias: bool = True,
strict_img_size: bool = True,
dynamic_img_pad: bool = True,
padding_mode='circular',
conv3d=False,
dtype=None,
device=None,
operations=None,
):
super().__init__()
try:
len(patch_size)
self.patch_size = patch_size
except:
if conv3d:
self.patch_size = (patch_size, patch_size, patch_size)
else:
self.patch_size = (patch_size, patch_size)
self.padding_mode = padding_mode
# flatten spatial dim and transpose to channels last, kept for bwd compat
self.flatten = flatten
self.strict_img_size = strict_img_size
self.dynamic_img_pad = dynamic_img_pad
if conv3d:
self.proj = operations.Conv3d(in_chans, embed_dim, kernel_size=patch_size, stride=patch_size, bias=bias, dtype=dtype, device=device)
else:
self.proj = operations.Conv2d(in_chans, embed_dim, kernel_size=patch_size, stride=patch_size, bias=bias, dtype=dtype, device=device)
self.norm = norm_layer(embed_dim) if norm_layer else nn.Identity()
def forward(self, x):
if self.dynamic_img_pad:
x = comfy.ldm.common_dit.pad_to_patch_size(x, self.patch_size, padding_mode=self.padding_mode)
x = self.proj(x)
if self.flatten:
x = x.flatten(2).transpose(1, 2) # NCHW -> NLC
x = self.norm(x)
return x
def modulate(x, shift, scale):
if shift is None:
shift = torch.zeros_like(scale)
return torch.addcmul(shift.unsqueeze(1), x, 1+ scale.unsqueeze(1))
#################################################################################
# Sine/Cosine Positional Embedding Functions #
#################################################################################
def get_2d_sincos_pos_embed(
embed_dim,
grid_size,
cls_token=False,
extra_tokens=0,
scaling_factor=None,
offset=None,
):
"""
grid_size: int of the grid height and width
return:
pos_embed: [grid_size*grid_size, embed_dim] or [1+grid_size*grid_size, embed_dim] (w/ or w/o cls_token)
"""
grid_h = np.arange(grid_size, dtype=np.float32)
grid_w = np.arange(grid_size, dtype=np.float32)
grid = np.meshgrid(grid_w, grid_h) # here w goes first
grid = np.stack(grid, axis=0)
if scaling_factor is not None:
grid = grid / scaling_factor
if offset is not None:
grid = grid - offset
grid = grid.reshape([2, 1, grid_size, grid_size])
pos_embed = get_2d_sincos_pos_embed_from_grid(embed_dim, grid)
if cls_token and extra_tokens > 0:
pos_embed = np.concatenate(
[np.zeros([extra_tokens, embed_dim]), pos_embed], axis=0
)
return pos_embed
def get_2d_sincos_pos_embed_from_grid(embed_dim, grid):
assert embed_dim % 2 == 0
# use half of dimensions to encode grid_h
emb_h = get_1d_sincos_pos_embed_from_grid(embed_dim // 2, grid[0]) # (H*W, D/2)
emb_w = get_1d_sincos_pos_embed_from_grid(embed_dim // 2, grid[1]) # (H*W, D/2)
emb = np.concatenate([emb_h, emb_w], axis=1) # (H*W, D)
return emb
def get_1d_sincos_pos_embed_from_grid(embed_dim, pos):
"""
embed_dim: output dimension for each position
pos: a list of positions to be encoded: size (M,)
out: (M, D)
"""
assert embed_dim % 2 == 0
omega = np.arange(embed_dim // 2, dtype=np.float64)
omega /= embed_dim / 2.0
omega = 1.0 / 10000**omega # (D/2,)
pos = pos.reshape(-1) # (M,)
out = np.einsum("m,d->md", pos, omega) # (M, D/2), outer product
emb_sin = np.sin(out) # (M, D/2)
emb_cos = np.cos(out) # (M, D/2)
emb = np.concatenate([emb_sin, emb_cos], axis=1) # (M, D)
return emb
def get_1d_sincos_pos_embed_from_grid_torch(embed_dim, pos, device=None, dtype=torch.float32):
omega = torch.arange(embed_dim // 2, device=device, dtype=dtype)
omega /= embed_dim / 2.0
omega = 1.0 / 10000**omega # (D/2,)
pos = pos.reshape(-1) # (M,)
out = torch.einsum("m,d->md", pos, omega) # (M, D/2), outer product
emb_sin = torch.sin(out) # (M, D/2)
emb_cos = torch.cos(out) # (M, D/2)
emb = torch.cat([emb_sin, emb_cos], dim=1) # (M, D)
return emb
def get_2d_sincos_pos_embed_torch(embed_dim, w, h, val_center=7.5, val_magnitude=7.5, device=None, dtype=torch.float32):
small = min(h, w)
val_h = (h / small) * val_magnitude
val_w = (w / small) * val_magnitude
grid_h, grid_w = torch.meshgrid(torch.linspace(-val_h + val_center, val_h + val_center, h, device=device, dtype=dtype), torch.linspace(-val_w + val_center, val_w + val_center, w, device=device, dtype=dtype), indexing='ij')
emb_h = get_1d_sincos_pos_embed_from_grid_torch(embed_dim // 2, grid_h, device=device, dtype=dtype)
emb_w = get_1d_sincos_pos_embed_from_grid_torch(embed_dim // 2, grid_w, device=device, dtype=dtype)
emb = torch.cat([emb_w, emb_h], dim=1) # (H*W, D)
return emb
#################################################################################
# Embedding Layers for Timesteps and Class Labels #
#################################################################################
class TimestepEmbedder(nn.Module):
"""
Embeds scalar timesteps into vector representations.
"""
def __init__(self, hidden_size, frequency_embedding_size=256, dtype=None, device=None, operations=None):
super().__init__()
self.mlp = nn.Sequential(
operations.Linear(frequency_embedding_size, hidden_size, bias=True, dtype=dtype, device=device),
nn.SiLU(),
operations.Linear(hidden_size, hidden_size, bias=True, dtype=dtype, device=device),
)
self.frequency_embedding_size = frequency_embedding_size
def forward(self, t, dtype, **kwargs):
t_freq = timestep_embedding(t, self.frequency_embedding_size).to(dtype)
t_emb = self.mlp(t_freq)
return t_emb
class VectorEmbedder(nn.Module):
"""
Embeds a flat vector of dimension input_dim
"""
def __init__(self, input_dim: int, hidden_size: int, dtype=None, device=None, operations=None):
super().__init__()
self.mlp = nn.Sequential(
operations.Linear(input_dim, hidden_size, bias=True, dtype=dtype, device=device),
nn.SiLU(),
operations.Linear(hidden_size, hidden_size, bias=True, dtype=dtype, device=device),
)
def forward(self, x: torch.Tensor) -> torch.Tensor:
emb = self.mlp(x)
return emb
#################################################################################
# Core DiT Model #
#################################################################################
def split_qkv(qkv, head_dim):
qkv = qkv.reshape(qkv.shape[0], qkv.shape[1], 3, -1, head_dim).movedim(2, 0)
return qkv[0], qkv[1], qkv[2]
class SelfAttention(nn.Module):
ATTENTION_MODES = ("xformers", "torch", "torch-hb", "math", "debug")
def __init__(
self,
dim: int,
num_heads: int = 8,
qkv_bias: bool = False,
qk_scale: Optional[float] = None,
proj_drop: float = 0.0,
attn_mode: str = "xformers",
pre_only: bool = False,
qk_norm: Optional[str] = None,
rmsnorm: bool = False,
dtype=None,
device=None,
operations=None,
):
super().__init__()
self.num_heads = num_heads
self.head_dim = dim // num_heads
self.qkv = operations.Linear(dim, dim * 3, bias=qkv_bias, dtype=dtype, device=device)
if not pre_only:
self.proj = operations.Linear(dim, dim, dtype=dtype, device=device)
self.proj_drop = nn.Dropout(proj_drop)
assert attn_mode in self.ATTENTION_MODES
self.attn_mode = attn_mode
self.pre_only = pre_only
if qk_norm == "rms":
self.ln_q = RMSNorm(self.head_dim, elementwise_affine=True, eps=1.0e-6, dtype=dtype, device=device)
self.ln_k = RMSNorm(self.head_dim, elementwise_affine=True, eps=1.0e-6, dtype=dtype, device=device)
elif qk_norm == "ln":
self.ln_q = operations.LayerNorm(self.head_dim, elementwise_affine=True, eps=1.0e-6, dtype=dtype, device=device)
self.ln_k = operations.LayerNorm(self.head_dim, elementwise_affine=True, eps=1.0e-6, dtype=dtype, device=device)
elif qk_norm is None:
self.ln_q = nn.Identity()
self.ln_k = nn.Identity()
else:
raise ValueError(qk_norm)
def pre_attention(self, x: torch.Tensor) -> torch.Tensor:
B, L, C = x.shape
qkv = self.qkv(x)
q, k, v = split_qkv(qkv, self.head_dim)
q = self.ln_q(q).reshape(q.shape[0], q.shape[1], -1)
k = self.ln_k(k).reshape(q.shape[0], q.shape[1], -1)
return (q, k, v)
def post_attention(self, x: torch.Tensor) -> torch.Tensor:
assert not self.pre_only
x = self.proj(x)
x = self.proj_drop(x)
return x
def forward(self, x: torch.Tensor) -> torch.Tensor:
q, k, v = self.pre_attention(x)
x = optimized_attention(
q, k, v, heads=self.num_heads
)
x = self.post_attention(x)
return x
class RMSNorm(torch.nn.Module):
def __init__(
self, dim: int, elementwise_affine: bool = False, eps: float = 1e-6, device=None, dtype=None, **kwargs
):
"""
Initialize the RMSNorm normalization layer.
Args:
dim (int): The dimension of the input tensor.
eps (float, optional): A small value added to the denominator for numerical stability. Default is 1e-6.
Attributes:
eps (float): A small value added to the denominator for numerical stability.
weight (nn.Parameter): Learnable scaling parameter.
"""
super().__init__()
self.eps = eps
self.learnable_scale = elementwise_affine
if self.learnable_scale:
self.weight = nn.Parameter(torch.empty(dim, device=device, dtype=dtype))
else:
self.register_parameter("weight", None)
def forward(self, x):
return comfy.ldm.common_dit.rms_norm(x, self.weight, self.eps)
class SwiGLUFeedForward(nn.Module):
def __init__(
self,
dim: int,
hidden_dim: int,
multiple_of: int,
ffn_dim_multiplier: Optional[float] = None,
):
"""
Initialize the FeedForward module.
Args:
dim (int): Input dimension.
hidden_dim (int): Hidden dimension of the feedforward layer.
multiple_of (int): Value to ensure hidden dimension is a multiple of this value.
ffn_dim_multiplier (float, optional): Custom multiplier for hidden dimension. Defaults to None.
Attributes:
w1 (ColumnParallelLinear): Linear transformation for the first layer.
w2 (RowParallelLinear): Linear transformation for the second layer.
w3 (ColumnParallelLinear): Linear transformation for the third layer.
"""
super().__init__()
hidden_dim = int(2 * hidden_dim / 3)
# custom dim factor multiplier
if ffn_dim_multiplier is not None:
hidden_dim = int(ffn_dim_multiplier * hidden_dim)
hidden_dim = multiple_of * ((hidden_dim + multiple_of - 1) // multiple_of)
self.w1 = nn.Linear(dim, hidden_dim, bias=False)
self.w2 = nn.Linear(hidden_dim, dim, bias=False)
self.w3 = nn.Linear(dim, hidden_dim, bias=False)
def forward(self, x):
return self.w2(nn.functional.silu(self.w1(x)) * self.w3(x))
class DismantledBlock(nn.Module):
"""
A DiT block with gated adaptive layer norm (adaLN) conditioning.
"""
ATTENTION_MODES = ("xformers", "torch", "torch-hb", "math", "debug")
def __init__(
self,
hidden_size: int,
num_heads: int,
mlp_ratio: float = 4.0,
attn_mode: str = "xformers",
qkv_bias: bool = False,
pre_only: bool = False,
rmsnorm: bool = False,
scale_mod_only: bool = False,
swiglu: bool = False,
qk_norm: Optional[str] = None,
x_block_self_attn: bool = False,
dtype=None,
device=None,
operations=None,
**block_kwargs,
):
super().__init__()
assert attn_mode in self.ATTENTION_MODES
if not rmsnorm:
self.norm1 = operations.LayerNorm(hidden_size, elementwise_affine=False, eps=1e-6, dtype=dtype, device=device)
else:
self.norm1 = RMSNorm(hidden_size, elementwise_affine=False, eps=1e-6)
self.attn = SelfAttention(
dim=hidden_size,
num_heads=num_heads,
qkv_bias=qkv_bias,
attn_mode=attn_mode,
pre_only=pre_only,
qk_norm=qk_norm,
rmsnorm=rmsnorm,
dtype=dtype,
device=device,
operations=operations
)
if x_block_self_attn:
assert not pre_only
assert not scale_mod_only
self.x_block_self_attn = True
self.attn2 = SelfAttention(
dim=hidden_size,
num_heads=num_heads,
qkv_bias=qkv_bias,
attn_mode=attn_mode,
pre_only=False,
qk_norm=qk_norm,
rmsnorm=rmsnorm,
dtype=dtype,
device=device,
operations=operations
)
else:
self.x_block_self_attn = False
if not pre_only:
if not rmsnorm:
self.norm2 = operations.LayerNorm(
hidden_size, elementwise_affine=False, eps=1e-6, dtype=dtype, device=device
)
else:
self.norm2 = RMSNorm(hidden_size, elementwise_affine=False, eps=1e-6)
mlp_hidden_dim = int(hidden_size * mlp_ratio)
if not pre_only:
if not swiglu:
self.mlp = Mlp(
in_features=hidden_size,
hidden_features=mlp_hidden_dim,
act_layer=lambda: nn.GELU(approximate="tanh"),
drop=0,
dtype=dtype,
device=device,
operations=operations
)
else:
self.mlp = SwiGLUFeedForward(
dim=hidden_size,
hidden_dim=mlp_hidden_dim,
multiple_of=256,
)
self.scale_mod_only = scale_mod_only
if x_block_self_attn:
assert not pre_only
assert not scale_mod_only
n_mods = 9
elif not scale_mod_only:
n_mods = 6 if not pre_only else 2
else:
n_mods = 4 if not pre_only else 1
self.adaLN_modulation = nn.Sequential(
nn.SiLU(), operations.Linear(hidden_size, n_mods * hidden_size, bias=True, dtype=dtype, device=device)
)
self.pre_only = pre_only
def pre_attention(self, x: torch.Tensor, c: torch.Tensor) -> torch.Tensor:
if not self.pre_only:
if not self.scale_mod_only:
(
shift_msa,
scale_msa,
gate_msa,
shift_mlp,
scale_mlp,
gate_mlp,
) = self.adaLN_modulation(c).chunk(6, dim=1)
else:
shift_msa = None
shift_mlp = None
(
scale_msa,
gate_msa,
scale_mlp,
gate_mlp,
) = self.adaLN_modulation(
c
).chunk(4, dim=1)
qkv = self.attn.pre_attention(modulate(self.norm1(x), shift_msa, scale_msa))
return qkv, (
x,
gate_msa,
shift_mlp,
scale_mlp,
gate_mlp,
)
else:
if not self.scale_mod_only:
(
shift_msa,
scale_msa,
) = self.adaLN_modulation(
c
).chunk(2, dim=1)
else:
shift_msa = None
scale_msa = self.adaLN_modulation(c)
qkv = self.attn.pre_attention(modulate(self.norm1(x), shift_msa, scale_msa))
return qkv, None
def post_attention(self, attn, x, gate_msa, shift_mlp, scale_mlp, gate_mlp):
assert not self.pre_only
x = x + gate_msa.unsqueeze(1) * self.attn.post_attention(attn)
x = x + gate_mlp.unsqueeze(1) * self.mlp(
modulate(self.norm2(x), shift_mlp, scale_mlp)
)
return x
def pre_attention_x(self, x: torch.Tensor, c: torch.Tensor) -> torch.Tensor:
assert self.x_block_self_attn
(
shift_msa,
scale_msa,
gate_msa,
shift_mlp,
scale_mlp,
gate_mlp,
shift_msa2,
scale_msa2,
gate_msa2,
) = self.adaLN_modulation(c).chunk(9, dim=1)
x_norm = self.norm1(x)
qkv = self.attn.pre_attention(modulate(x_norm, shift_msa, scale_msa))
qkv2 = self.attn2.pre_attention(modulate(x_norm, shift_msa2, scale_msa2))
return qkv, qkv2, (
x,
gate_msa,
shift_mlp,
scale_mlp,
gate_mlp,
gate_msa2,
)
def post_attention_x(self, attn, attn2, x, gate_msa, shift_mlp, scale_mlp, gate_mlp, gate_msa2):
assert not self.pre_only
attn1 = self.attn.post_attention(attn)
attn2 = self.attn2.post_attention(attn2)
x = gate_cat(x, gate_msa, gate_msa2, attn1, attn2)
x = x + gate_mlp.unsqueeze(1) * self.mlp(
modulate(self.norm2(x), shift_mlp, scale_mlp)
)
return x
def forward(self, x: torch.Tensor, c: torch.Tensor) -> torch.Tensor:
assert not self.pre_only
if self.x_block_self_attn:
qkv, qkv2, intermediates = self.pre_attention_x(x, c)
attn, _ = optimized_attention(
qkv[0], qkv[1], qkv[2],
num_heads=self.attn.num_heads,
)
attn2, _ = optimized_attention(
qkv2[0], qkv2[1], qkv2[2],
num_heads=self.attn2.num_heads,
)
return self.post_attention_x(attn, attn2, *intermediates)
else:
qkv, intermediates = self.pre_attention(x, c)
attn = optimized_attention(
qkv[0], qkv[1], qkv[2],
heads=self.attn.num_heads,
)
return self.post_attention(attn, *intermediates)
def gate_cat(x, gate_msa, gate_msa2, attn1, attn2):
out1 = gate_msa.unsqueeze(1) * attn1
out2 = gate_msa2.unsqueeze(1) * attn2
x = torch.stack([x, out1, out2], dim=0).sum(dim=0)
return x
def block_mixing(*args, use_checkpoint=True, **kwargs):
if use_checkpoint:
return torch.utils.checkpoint.checkpoint(
_block_mixing, *args, use_reentrant=False, **kwargs
)
else:
return _block_mixing(*args, **kwargs)
def _block_mixing(context, x, context_block, x_block, c):
context_qkv, context_intermediates = context_block.pre_attention(context, c)
if x_block.x_block_self_attn:
x_qkv, x_qkv2, x_intermediates = x_block.pre_attention_x(x, c)
else:
x_qkv, x_intermediates = x_block.pre_attention(x, c)
o = []
for t in range(3):
o.append(torch.cat((context_qkv[t], x_qkv[t]), dim=1))
qkv = tuple(o)
attn = optimized_attention(
qkv[0], qkv[1], qkv[2],
heads=x_block.attn.num_heads,
)
context_attn, x_attn = (
attn[:, : context_qkv[0].shape[1]],
attn[:, context_qkv[0].shape[1] :],
)
if not context_block.pre_only:
context = context_block.post_attention(context_attn, *context_intermediates)
else:
context = None
if x_block.x_block_self_attn:
attn2 = optimized_attention(
x_qkv2[0], x_qkv2[1], x_qkv2[2],
heads=x_block.attn2.num_heads,
)
x = x_block.post_attention_x(x_attn, attn2, *x_intermediates)
else:
x = x_block.post_attention(x_attn, *x_intermediates)
return context, x
class JointBlock(nn.Module):
"""just a small wrapper to serve as a fsdp unit"""
def __init__(
self,
*args,
**kwargs,
):
super().__init__()
pre_only = kwargs.pop("pre_only")
qk_norm = kwargs.pop("qk_norm", None)
x_block_self_attn = kwargs.pop("x_block_self_attn", False)
self.context_block = DismantledBlock(*args, pre_only=pre_only, qk_norm=qk_norm, **kwargs)
self.x_block = DismantledBlock(*args,
pre_only=False,
qk_norm=qk_norm,
x_block_self_attn=x_block_self_attn,
**kwargs)
def forward(self, *args, **kwargs):
return block_mixing(
*args, context_block=self.context_block, x_block=self.x_block, **kwargs
)
class FinalLayer(nn.Module):
"""
The final layer of DiT.
"""
def __init__(
self,
hidden_size: int,
patch_size: int,
out_channels: int,
total_out_channels: Optional[int] = None,
dtype=None,
device=None,
operations=None,
):
super().__init__()
self.norm_final = operations.LayerNorm(hidden_size, elementwise_affine=False, eps=1e-6, dtype=dtype, device=device)
self.linear = (
operations.Linear(hidden_size, patch_size * patch_size * out_channels, bias=True, dtype=dtype, device=device)
if (total_out_channels is None)
else operations.Linear(hidden_size, total_out_channels, bias=True, dtype=dtype, device=device)
)
self.adaLN_modulation = nn.Sequential(
nn.SiLU(), operations.Linear(hidden_size, 2 * hidden_size, bias=True, dtype=dtype, device=device)
)
def forward(self, x: torch.Tensor, c: torch.Tensor) -> torch.Tensor:
shift, scale = self.adaLN_modulation(c).chunk(2, dim=1)
x = modulate(self.norm_final(x), shift, scale)
x = self.linear(x)
return x
class SelfAttentionContext(nn.Module):
def __init__(self, dim, heads=8, dim_head=64, dtype=None, device=None, operations=None):
super().__init__()
dim_head = dim // heads
inner_dim = dim
self.heads = heads
self.dim_head = dim_head
self.qkv = operations.Linear(dim, dim * 3, bias=True, dtype=dtype, device=device)
self.proj = operations.Linear(inner_dim, dim, dtype=dtype, device=device)
def forward(self, x):
qkv = self.qkv(x)
q, k, v = split_qkv(qkv, self.dim_head)
x = optimized_attention(q.reshape(q.shape[0], q.shape[1], -1), k, v, heads=self.heads)
return self.proj(x)
class ContextProcessorBlock(nn.Module):
def __init__(self, context_size, dtype=None, device=None, operations=None):
super().__init__()
self.norm1 = operations.LayerNorm(context_size, elementwise_affine=False, eps=1e-6, dtype=dtype, device=device)
self.attn = SelfAttentionContext(context_size, dtype=dtype, device=device, operations=operations)
self.norm2 = operations.LayerNorm(context_size, elementwise_affine=False, eps=1e-6, dtype=dtype, device=device)
self.mlp = Mlp(in_features=context_size, hidden_features=(context_size * 4), act_layer=lambda: nn.GELU(approximate="tanh"), drop=0, dtype=dtype, device=device, operations=operations)
def forward(self, x):
x += self.attn(self.norm1(x))
x += self.mlp(self.norm2(x))
return x
class ContextProcessor(nn.Module):
def __init__(self, context_size, num_layers, dtype=None, device=None, operations=None):
super().__init__()
self.layers = torch.nn.ModuleList([ContextProcessorBlock(context_size, dtype=dtype, device=device, operations=operations) for i in range(num_layers)])
self.norm = operations.LayerNorm(context_size, elementwise_affine=False, eps=1e-6, dtype=dtype, device=device)
def forward(self, x):
for i, l in enumerate(self.layers):
x = l(x)
return self.norm(x)
class MMDiT(nn.Module):
"""
Diffusion model with a Transformer backbone.
"""
def __init__(
self,
input_size: int = 32,
patch_size: int = 2,
in_channels: int = 4,
depth: int = 28,
# hidden_size: Optional[int] = None,
# num_heads: Optional[int] = None,
mlp_ratio: float = 4.0,
learn_sigma: bool = False,
adm_in_channels: Optional[int] = None,
context_embedder_config: Optional[Dict] = None,
compile_core: bool = False,
use_checkpoint: bool = False,
register_length: int = 0,
attn_mode: str = "torch",
rmsnorm: bool = False,
scale_mod_only: bool = False,
swiglu: bool = False,
out_channels: Optional[int] = None,
pos_embed_scaling_factor: Optional[float] = None,
pos_embed_offset: Optional[float] = None,
pos_embed_max_size: Optional[int] = None,
num_patches = None,
qk_norm: Optional[str] = None,
qkv_bias: bool = True,
context_processor_layers = None,
x_block_self_attn: bool = False,
x_block_self_attn_layers: Optional[List[int]] = [],
context_size = 4096,
num_blocks = None,
final_layer = True,
skip_blocks = False,
dtype = None, #TODO
device = None,
operations = None,
):
super().__init__()
self.dtype = dtype
self.learn_sigma = learn_sigma
self.in_channels = in_channels
default_out_channels = in_channels * 2 if learn_sigma else in_channels
self.out_channels = default(out_channels, default_out_channels)
self.patch_size = patch_size
self.pos_embed_scaling_factor = pos_embed_scaling_factor
self.pos_embed_offset = pos_embed_offset
self.pos_embed_max_size = pos_embed_max_size
self.x_block_self_attn_layers = x_block_self_attn_layers
# hidden_size = default(hidden_size, 64 * depth)
# num_heads = default(num_heads, hidden_size // 64)
# apply magic --> this defines a head_size of 64
self.hidden_size = 64 * depth
num_heads = depth
if num_blocks is None:
num_blocks = depth
self.depth = depth
self.num_heads = num_heads
self.x_embedder = PatchEmbed(
input_size,
patch_size,
in_channels,
self.hidden_size,
bias=True,
strict_img_size=self.pos_embed_max_size is None,
dtype=dtype,
device=device,
operations=operations
)
self.t_embedder = TimestepEmbedder(self.hidden_size, dtype=dtype, device=device, operations=operations)
self.y_embedder = None
if adm_in_channels is not None:
assert isinstance(adm_in_channels, int)
self.y_embedder = VectorEmbedder(adm_in_channels, self.hidden_size, dtype=dtype, device=device, operations=operations)
if context_processor_layers is not None:
self.context_processor = ContextProcessor(context_size, context_processor_layers, dtype=dtype, device=device, operations=operations)
else:
self.context_processor = None
self.context_embedder = nn.Identity()
if context_embedder_config is not None:
if context_embedder_config["target"] == "torch.nn.Linear":
self.context_embedder = operations.Linear(**context_embedder_config["params"], dtype=dtype, device=device)
self.register_length = register_length
if self.register_length > 0:
self.register = nn.Parameter(torch.randn(1, register_length, self.hidden_size, dtype=dtype, device=device))
# num_patches = self.x_embedder.num_patches
# Will use fixed sin-cos embedding:
# just use a buffer already
if num_patches is not None:
self.register_buffer(
"pos_embed",
torch.empty(1, num_patches, self.hidden_size, dtype=dtype, device=device),
)
else:
self.pos_embed = None
self.use_checkpoint = use_checkpoint
if not skip_blocks:
self.joint_blocks = nn.ModuleList(
[
JointBlock(
self.hidden_size,
num_heads,
mlp_ratio=mlp_ratio,
qkv_bias=qkv_bias,
attn_mode=attn_mode,
pre_only=(i == num_blocks - 1) and final_layer,
rmsnorm=rmsnorm,
scale_mod_only=scale_mod_only,
swiglu=swiglu,
qk_norm=qk_norm,
x_block_self_attn=(i in self.x_block_self_attn_layers) or x_block_self_attn,
dtype=dtype,
device=device,
operations=operations,
)
for i in range(num_blocks)
]
)
if final_layer:
self.final_layer = FinalLayer(self.hidden_size, patch_size, self.out_channels, dtype=dtype, device=device, operations=operations)
if compile_core:
assert False
self.forward_core_with_concat = torch.compile(self.forward_core_with_concat)
def cropped_pos_embed(self, hw, device=None):
p = self.x_embedder.patch_size[0]
h, w = hw
# patched size
h = (h + 1) // p
w = (w + 1) // p
if self.pos_embed is None:
return get_2d_sincos_pos_embed_torch(self.hidden_size, w, h, device=device)
assert self.pos_embed_max_size is not None
assert h <= self.pos_embed_max_size, (h, self.pos_embed_max_size)
assert w <= self.pos_embed_max_size, (w, self.pos_embed_max_size)
top = (self.pos_embed_max_size - h) // 2
left = (self.pos_embed_max_size - w) // 2
spatial_pos_embed = rearrange(
self.pos_embed,
"1 (h w) c -> 1 h w c",
h=self.pos_embed_max_size,
w=self.pos_embed_max_size,
)
spatial_pos_embed = spatial_pos_embed[:, top : top + h, left : left + w, :]
spatial_pos_embed = rearrange(spatial_pos_embed, "1 h w c -> 1 (h w) c")
# print(spatial_pos_embed, top, left, h, w)
# # t = get_2d_sincos_pos_embed_torch(self.hidden_size, w, h, 7.875, 7.875, device=device) #matches exactly for 1024 res
# t = get_2d_sincos_pos_embed_torch(self.hidden_size, w, h, 7.5, 7.5, device=device) #scales better
# # print(t)
# return t
return spatial_pos_embed
def unpatchify(self, x, hw=None):
"""
x: (N, T, patch_size**2 * C)
imgs: (N, H, W, C)
"""
c = self.out_channels
p = self.x_embedder.patch_size[0]
if hw is None:
h = w = int(x.shape[1] ** 0.5)
else:
h, w = hw
h = (h + 1) // p
w = (w + 1) // p
assert h * w == x.shape[1]
x = x.reshape(shape=(x.shape[0], h, w, p, p, c))
x = torch.einsum("nhwpqc->nchpwq", x)
imgs = x.reshape(shape=(x.shape[0], c, h * p, w * p))
return imgs
def forward_core_with_concat(
self,
x: torch.Tensor,
c_mod: torch.Tensor,
context: Optional[torch.Tensor] = None,
control = None,
transformer_options = {},
) -> torch.Tensor:
patches_replace = transformer_options.get("patches_replace", {})
if self.register_length > 0:
context = torch.cat(
(
repeat(self.register, "1 ... -> b ...", b=x.shape[0]),
default(context, torch.Tensor([]).type_as(x)),
),
1,
)
# context is B, L', D
# x is B, L, D
blocks_replace = patches_replace.get("dit", {})
blocks = len(self.joint_blocks)
for i in range(blocks):
if ("double_block", i) in blocks_replace:
def block_wrap(args):
out = {}
out["txt"], out["img"] = self.joint_blocks[i](args["txt"], args["img"], c=args["vec"])
return out
out = blocks_replace[("double_block", i)]({"img": x, "txt": context, "vec": c_mod}, {"original_block": block_wrap})
context = out["txt"]
x = out["img"]
else:
context, x = self.joint_blocks[i](
context,
x,
c=c_mod,
use_checkpoint=self.use_checkpoint,
)
if control is not None:
control_o = control.get("output")
if i < len(control_o):
add = control_o[i]
if add is not None:
x += add
x = self.final_layer(x, c_mod) # (N, T, patch_size ** 2 * out_channels)
return x
def forward(
self,
x: torch.Tensor,
t: torch.Tensor,
y: Optional[torch.Tensor] = None,
context: Optional[torch.Tensor] = None,
control = None,
transformer_options = {},
) -> torch.Tensor:
"""
Forward pass of DiT.
x: (N, C, H, W) tensor of spatial inputs (images or latent representations of images)
t: (N,) tensor of diffusion timesteps
y: (N,) tensor of class labels
"""
if self.context_processor is not None:
context = self.context_processor(context)
hw = x.shape[-2:]
x = self.x_embedder(x) + comfy.ops.cast_to_input(self.cropped_pos_embed(hw, device=x.device), x)
c = self.t_embedder(t, dtype=x.dtype) # (N, D)
if y is not None and self.y_embedder is not None:
y = self.y_embedder(y) # (N, D)
c = c + y # (N, D)
if context is not None:
context = self.context_embedder(context)
x = self.forward_core_with_concat(x, c, context, control, transformer_options)
x = self.unpatchify(x, hw=hw) # (N, out_channels, H, W)
return x[:,:,:hw[-2],:hw[-1]]
class OpenAISignatureMMDITWrapper(MMDiT):
def forward(
self,
x: torch.Tensor,
timesteps: torch.Tensor,
context: Optional[torch.Tensor] = None,
y: Optional[torch.Tensor] = None,
control = None,
transformer_options = {},
**kwargs,
) -> torch.Tensor:
return super().forward(x, timesteps, context=context, y=y, control=control, transformer_options=transformer_options)
# pytorch_diffusion + derived encoder decoder
import math
import torch
import torch.nn as nn
import numpy as np
import logging
from comfy import model_management
import comfy.ops
ops = comfy.ops.disable_weight_init
if model_management.xformers_enabled_vae():
import xformers
import xformers.ops
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
def nonlinearity(x):
# swish
return torch.nn.functional.silu(x)
def Normalize(in_channels, num_groups=32):
return ops.GroupNorm(num_groups=num_groups, num_channels=in_channels, eps=1e-6, affine=True)
class VideoConv3d(nn.Module):
def __init__(self, n_channels, out_channels, kernel_size, stride=1, dilation=1, padding_mode='replicate', padding=1, **kwargs):
super().__init__()
self.padding_mode = padding_mode
if padding != 0:
padding = (padding, padding, padding, padding, kernel_size - 1, 0)
else:
kwargs["padding"] = padding
self.padding = padding
self.conv = ops.Conv3d(n_channels, out_channels, kernel_size, stride=stride, dilation=dilation, **kwargs)
def forward(self, x):
if self.padding != 0:
x = torch.nn.functional.pad(x, self.padding, mode=self.padding_mode)
return self.conv(x)
def interpolate_up(x, scale_factor):
try:
return torch.nn.functional.interpolate(x, scale_factor=scale_factor, mode="nearest")
except: #operation not implemented for bf16
orig_shape = list(x.shape)
out_shape = orig_shape[:2]
for i in range(len(orig_shape) - 2):
out_shape.append(round(orig_shape[i + 2] * scale_factor[i]))
out = torch.empty(out_shape, dtype=x.dtype, layout=x.layout, device=x.device)
split = 8
l = out.shape[1] // split
for i in range(0, out.shape[1], l):
out[:,i:i+l] = torch.nn.functional.interpolate(x[:,i:i+l].to(torch.float32), scale_factor=scale_factor, mode="nearest").to(x.dtype)
return out
class Upsample(nn.Module):
def __init__(self, in_channels, with_conv, conv_op=ops.Conv2d, scale_factor=2.0):
super().__init__()
self.with_conv = with_conv
self.scale_factor = scale_factor
if self.with_conv:
self.conv = conv_op(in_channels,
in_channels,
kernel_size=3,
stride=1,
padding=1)
def forward(self, x):
scale_factor = self.scale_factor
if isinstance(scale_factor, (int, float)):
scale_factor = (scale_factor,) * (x.ndim - 2)
if x.ndim == 5 and scale_factor[0] > 1.0:
t = x.shape[2]
if t > 1:
a, b = x.split((1, t - 1), dim=2)
del x
b = interpolate_up(b, scale_factor)
else:
a = x
a = interpolate_up(a.squeeze(2), scale_factor=scale_factor[1:]).unsqueeze(2)
if t > 1:
x = torch.cat((a, b), dim=2)
else:
x = a
else:
x = interpolate_up(x, scale_factor)
if self.with_conv:
x = self.conv(x)
return x
class Downsample(nn.Module):
def __init__(self, in_channels, with_conv, stride=2, conv_op=ops.Conv2d):
super().__init__()
self.with_conv = with_conv
if self.with_conv:
# no asymmetric padding in torch conv, must do it ourselves
self.conv = conv_op(in_channels,
in_channels,
kernel_size=3,
stride=stride,
padding=0)
def forward(self, x):
if self.with_conv:
if x.ndim == 4:
pad = (0, 1, 0, 1)
mode = "constant"
x = torch.nn.functional.pad(x, pad, mode=mode, value=0)
elif x.ndim == 5:
pad = (1, 1, 1, 1, 2, 0)
mode = "replicate"
x = torch.nn.functional.pad(x, pad, mode=mode)
x = self.conv(x)
else:
x = torch.nn.functional.avg_pool2d(x, kernel_size=2, stride=2)
return x
class ResnetBlock(nn.Module):
def __init__(self, *, in_channels, out_channels=None, conv_shortcut=False,
dropout, temb_channels=512, conv_op=ops.Conv2d):
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.swish = torch.nn.SiLU(inplace=True)
self.norm1 = Normalize(in_channels)
self.conv1 = conv_op(in_channels,
out_channels,
kernel_size=3,
stride=1,
padding=1)
if temb_channels > 0:
self.temb_proj = ops.Linear(temb_channels,
out_channels)
self.norm2 = Normalize(out_channels)
self.dropout = torch.nn.Dropout(dropout, inplace=True)
self.conv2 = conv_op(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 = conv_op(in_channels,
out_channels,
kernel_size=3,
stride=1,
padding=1)
else:
self.nin_shortcut = conv_op(in_channels,
out_channels,
kernel_size=1,
stride=1,
padding=0)
def forward(self, x, temb):
h = x
h = self.norm1(h)
h = self.swish(h)
h = self.conv1(h)
if temb is not None:
h = h + self.temb_proj(self.swish(temb))[:,:,None,None]
h = self.norm2(h)
h = self.swish(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
@torch.compiler.disable()
def slice_attention(q, k, v):
r1 = torch.zeros_like(k, device=q.device)
scale = (int(q.shape[-1])**(-0.5))
mem_free_total = model_management.get_free_memory(q.device)
tensor_size = q.shape[0] * q.shape[1] * k.shape[2] * q.element_size()
modifier = 3 if q.element_size() == 2 else 2.5
mem_required = tensor_size * modifier
steps = 1
if mem_required > mem_free_total:
steps = 2**(math.ceil(math.log(mem_required / mem_free_total, 2)))
while True:
try:
slice_size = q.shape[1] // steps if (q.shape[1] % steps) == 0 else q.shape[1]
for i in range(0, q.shape[1], slice_size):
end = i + slice_size
s1 = torch.bmm(q[:, i:end], k) * scale
s2 = torch.nn.functional.softmax(s1, dim=2).permute(0,2,1)
del s1
r1[:, :, i:end] = torch.bmm(v, s2)
del s2
break
except model_management.OOM_EXCEPTION as e:
model_management.soft_empty_cache(True)
steps *= 2
if steps > 128:
raise e
logging.warning("out of memory error, increasing steps and trying again {}".format(steps))
return r1
def normal_attention(q, k, v):
# compute attention
orig_shape = q.shape
b = orig_shape[0]
c = orig_shape[1]
q = q.reshape(b, c, -1)
q = q.permute(0, 2, 1) # b,hw,c
k = k.reshape(b, c, -1) # b,c,hw
v = v.reshape(b, c, -1)
r1 = slice_attention(q, k, v)
h_ = r1.reshape(orig_shape)
del r1
return h_
def xformers_attention(q, k, v):
# compute attention
orig_shape = q.shape
B = orig_shape[0]
C = orig_shape[1]
q, k, v = map(
lambda t: t.view(B, C, -1).transpose(1, 2).contiguous(),
(q, k, v),
)
try:
out = xformers.ops.memory_efficient_attention(q, k, v, attn_bias=None)
out = out.transpose(1, 2).reshape(orig_shape)
except NotImplementedError:
out = slice_attention(q.view(B, -1, C), k.view(B, -1, C).transpose(1, 2), v.view(B, -1, C).transpose(1, 2)).reshape(orig_shape)
return out
def pytorch_attention(q, k, v):
# compute attention
orig_shape = q.shape
B = orig_shape[0]
C = orig_shape[1]
q, k, v = map(
lambda t: t.view(B, 1, C, -1).transpose(2, 3).contiguous(),
(q, k, v),
)
try:
out = comfy.ops.scaled_dot_product_attention(q, k, v, attn_mask=None, dropout_p=0.0, is_causal=False)
out = out.transpose(2, 3).reshape(orig_shape)
except model_management.OOM_EXCEPTION:
logging.warning("scaled_dot_product_attention OOMed: switched to slice attention")
out = slice_attention(q.view(B, -1, C), k.view(B, -1, C).transpose(1, 2), v.view(B, -1, C).transpose(1, 2)).reshape(orig_shape)
return out
def vae_attention():
if model_management.xformers_enabled_vae():
logging.info("Using xformers attention in VAE")
return xformers_attention
elif model_management.pytorch_attention_enabled_vae():
logging.info("Using pytorch attention in VAE")
return pytorch_attention
else:
logging.info("Using split attention in VAE")
return normal_attention
class AttnBlock(nn.Module):
def __init__(self, in_channels, conv_op=ops.Conv2d):
super().__init__()
self.in_channels = in_channels
self.norm = Normalize(in_channels)
self.q = conv_op(in_channels,
in_channels,
kernel_size=1,
stride=1,
padding=0)
self.k = conv_op(in_channels,
in_channels,
kernel_size=1,
stride=1,
padding=0)
self.v = conv_op(in_channels,
in_channels,
kernel_size=1,
stride=1,
padding=0)
self.proj_out = conv_op(in_channels,
in_channels,
kernel_size=1,
stride=1,
padding=0)
self.optimized_attention = vae_attention()
def forward(self, x):
#print("######### AttnBlock forward #######")
#print("x.shape:",x.shape)
h_ = x
h_ = self.norm(h_)
q = self.q(h_)
k = self.k(h_)
v = self.v(h_)
h_ = self.optimized_attention(q, k, v)
h_ = self.proj_out(h_)
return x+h_
def make_attn(in_channels, attn_type="vanilla", attn_kwargs=None, conv_op=ops.Conv2d):
return AttnBlock(in_channels, conv_op=conv_op)
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([
ops.Linear(self.ch,
self.temb_ch),
ops.Linear(self.temb_ch,
self.temb_ch),
])
# downsampling
self.conv_in = ops.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 = ops.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",
conv3d=False, time_compress=None,
**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
if conv3d:
conv_op = VideoConv3d
mid_attn_conv_op = ops.Conv3d
else:
conv_op = ops.Conv2d
mid_attn_conv_op = ops.Conv2d
# downsampling
self.conv_in = conv_op(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,
conv_op=conv_op))
block_in = block_out
if curr_res in attn_resolutions:
attn.append(make_attn(block_in, attn_type=attn_type, conv_op=conv_op))
down = nn.Module()
down.block = block
down.attn = attn
if i_level != self.num_resolutions-1:
stride = 2
if time_compress is not None:
if (self.num_resolutions - 1 - i_level) > math.log2(time_compress):
stride = (1, 2, 2)
down.downsample = Downsample(block_in, resamp_with_conv, stride=stride, conv_op=conv_op)
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,
conv_op=conv_op)
self.mid.attn_1 = make_attn(block_in, attn_type=attn_type, conv_op=mid_attn_conv_op)
self.mid.block_2 = ResnetBlock(in_channels=block_in,
out_channels=block_in,
temb_channels=self.temb_ch,
dropout=dropout,
conv_op=conv_op)
# end
self.norm_out = Normalize(block_in)
self.conv_out = conv_op(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
# downsampling
#print("########### encoder forward ##########")
#print(x.shape)
h = 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](h, temb)
if len(self.down[i_level].attn) > 0:
h = self.down[i_level].attn[i_block](h)
if i_level != self.num_resolutions-1:
h = self.down[i_level].downsample(h)
# middle
h = self.mid.block_1(h, temb)
h = self.mid.attn_1(h)
h = self.mid.block_2(h, temb)
# end
h = self.norm_out(h)
h = nonlinearity(h)
h = self.conv_out(h)
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,
conv_out_op=ops.Conv2d,
resnet_op=ResnetBlock,
attn_op=AttnBlock,
conv3d=False,
time_compress=None,
**ignorekwargs):
super().__init__()
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
if conv3d:
conv_op = VideoConv3d
conv_out_op = VideoConv3d
mid_attn_conv_op = ops.Conv3d
else:
conv_op = ops.Conv2d
mid_attn_conv_op = ops.Conv2d
# compute block_in and curr_res at lowest res
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)
logging.debug("Working with z of shape {} = {} dimensions.".format(
self.z_shape, np.prod(self.z_shape)))
# z to block_in
self.conv_in = conv_op(z_channels,
block_in,
kernel_size=3,
stride=1,
padding=1)
# middle
self.mid = nn.Module()
self.mid.block_1 = resnet_op(in_channels=block_in,
out_channels=block_in,
temb_channels=self.temb_ch,
dropout=dropout,
conv_op=conv_op)
self.mid.attn_1 = attn_op(block_in, conv_op=mid_attn_conv_op)
self.mid.block_2 = resnet_op(in_channels=block_in,
out_channels=block_in,
temb_channels=self.temb_ch,
dropout=dropout,
conv_op=conv_op)
# 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(resnet_op(in_channels=block_in,
out_channels=block_out,
temb_channels=self.temb_ch,
dropout=dropout,
conv_op=conv_op))
block_in = block_out
if curr_res in attn_resolutions:
attn.append(attn_op(block_in, conv_op=conv_op))
up = nn.Module()
up.block = block
up.attn = attn
if i_level != 0:
scale_factor = 2.0
if time_compress is not None:
if i_level > math.log2(time_compress):
scale_factor = (1.0, 2.0, 2.0)
up.upsample = Upsample(block_in, resamp_with_conv, conv_op=conv_op, scale_factor=scale_factor)
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 = conv_out_op(block_in,
out_ch,
kernel_size=3,
stride=1,
padding=1)
def forward(self, z, **kwargs):
# timestep embedding
temb = None
# z to block_in
h = self.conv_in(z)
# middle
h = self.mid.block_1(h, temb, **kwargs)
h = self.mid.attn_1(h, **kwargs)
h = self.mid.block_2(h, temb, **kwargs)
# 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, **kwargs)
if len(self.up[i_level].attn) > 0:
h = self.up[i_level].attn[i_block](h, **kwargs)
if i_level != 0:
h = self.up[i_level].upsample(h)
# end
if self.give_pre_end:
return h
h = self.norm_out(h)
h = nonlinearity(h)
h = self.conv_out(h, **kwargs)
if self.tanh_out:
h = torch.tanh(h)
return h
from abc import abstractmethod
import torch as th
import torch.nn as nn
import torch.nn.functional as F
from einops import rearrange
import logging
from .util import (
checkpoint,
avg_pool_nd,
timestep_embedding,
AlphaBlender,
)
from ..attention import SpatialTransformer, SpatialVideoTransformer, default
from comfy.ldm.util import exists
import comfy.patcher_extension
import comfy.ops
ops = comfy.ops.disable_weight_init
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.
"""
#This is needed because accelerate makes a copy of transformer_options which breaks "transformer_index"
def forward_timestep_embed(ts, x, emb, context=None, transformer_options={}, output_shape=None, time_context=None, num_video_frames=None, image_only_indicator=None):
for layer in ts:
if isinstance(layer, VideoResBlock):
x = layer(x, emb, num_video_frames, image_only_indicator)
elif isinstance(layer, TimestepBlock):
x = layer(x, emb)
elif isinstance(layer, SpatialVideoTransformer):
x = layer(x, context, time_context, num_video_frames, image_only_indicator, transformer_options)
if "transformer_index" in transformer_options:
transformer_options["transformer_index"] += 1
elif isinstance(layer, SpatialTransformer):
x = layer(x, context, transformer_options)
if "transformer_index" in transformer_options:
transformer_options["transformer_index"] += 1
elif isinstance(layer, Upsample):
x = layer(x, output_shape=output_shape)
else:
if "patches" in transformer_options and "forward_timestep_embed_patch" in transformer_options["patches"]:
found_patched = False
for class_type, handler in transformer_options["patches"]["forward_timestep_embed_patch"]:
if isinstance(layer, class_type):
x = handler(layer, x, emb, context, transformer_options, output_shape, time_context, num_video_frames, image_only_indicator)
found_patched = True
break
if found_patched:
continue
x = layer(x)
return x
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, *args, **kwargs):
return forward_timestep_embed(self, *args, **kwargs)
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, dtype=None, device=None, operations=ops):
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 = operations.conv_nd(dims, self.channels, self.out_channels, 3, padding=padding, dtype=dtype, device=device)
def forward(self, x, output_shape=None):
assert x.shape[1] == self.channels
if self.dims == 3:
shape = [x.shape[2], x.shape[3] * 2, x.shape[4] * 2]
if output_shape is not None:
shape[1] = output_shape[3]
shape[2] = output_shape[4]
else:
shape = [x.shape[2] * 2, x.shape[3] * 2]
if output_shape is not None:
shape[0] = output_shape[2]
shape[1] = output_shape[3]
x = F.interpolate(x, size=shape, mode="nearest")
if self.use_conv:
x = self.conv(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, dtype=None, device=None, operations=ops):
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 = operations.conv_nd(
dims, self.channels, self.out_channels, 3, stride=stride, padding=padding, dtype=dtype, device=device
)
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 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 use_checkpoint: if True, use gradient checkpointing on this module.
:param up: if True, use this block for upsampling.
:param down: if True, use this block for downsampling.
"""
def __init__(
self,
channels,
emb_channels,
dropout,
out_channels=None,
use_conv=False,
use_scale_shift_norm=False,
dims=2,
use_checkpoint=False,
up=False,
down=False,
kernel_size=3,
exchange_temb_dims=False,
skip_t_emb=False,
dtype=None,
device=None,
operations=ops
):
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.exchange_temb_dims = exchange_temb_dims
if isinstance(kernel_size, list):
padding = [k // 2 for k in kernel_size]
else:
padding = kernel_size // 2
self.in_layers = nn.Sequential(
operations.GroupNorm(32, channels, dtype=dtype, device=device),
nn.SiLU(),
operations.conv_nd(dims, channels, self.out_channels, kernel_size, padding=padding, dtype=dtype, device=device),
)
self.updown = up or down
if up:
self.h_upd = Upsample(channels, False, dims, dtype=dtype, device=device)
self.x_upd = Upsample(channels, False, dims, dtype=dtype, device=device)
elif down:
self.h_upd = Downsample(channels, False, dims, dtype=dtype, device=device)
self.x_upd = Downsample(channels, False, dims, dtype=dtype, device=device)
else:
self.h_upd = self.x_upd = nn.Identity()
self.skip_t_emb = skip_t_emb
if self.skip_t_emb:
self.emb_layers = None
self.exchange_temb_dims = False
else:
self.emb_layers = nn.Sequential(
nn.SiLU(),
operations.Linear(
emb_channels,
2 * self.out_channels if use_scale_shift_norm else self.out_channels, dtype=dtype, device=device
),
)
self.out_layers = nn.Sequential(
operations.GroupNorm(32, self.out_channels, dtype=dtype, device=device),
nn.SiLU(),
nn.Dropout(p=dropout),
operations.conv_nd(dims, self.out_channels, self.out_channels, kernel_size, padding=padding, dtype=dtype, device=device)
,
)
if self.out_channels == channels:
self.skip_connection = nn.Identity()
elif use_conv:
self.skip_connection = operations.conv_nd(
dims, channels, self.out_channels, kernel_size, padding=padding, dtype=dtype, device=device
)
else:
self.skip_connection = operations.conv_nd(dims, channels, self.out_channels, 1, dtype=dtype, device=device)
def forward(self, x, emb):
"""
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.
"""
return checkpoint(
self._forward, (x, emb), self.parameters(), self.use_checkpoint
)
def _forward(self, x, emb):
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 = None
if not self.skip_t_emb:
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:]
h = out_norm(h)
if emb_out is not None:
scale, shift = th.chunk(emb_out, 2, dim=1)
h *= (1 + scale)
h += shift
h = out_rest(h)
else:
if emb_out is not None:
if self.exchange_temb_dims:
emb_out = emb_out.movedim(1, 2)
h = h + emb_out
h = self.out_layers(h)
return self.skip_connection(x) + h
class VideoResBlock(ResBlock):
def __init__(
self,
channels: int,
emb_channels: int,
dropout: float,
video_kernel_size=3,
merge_strategy: str = "fixed",
merge_factor: float = 0.5,
out_channels=None,
use_conv: bool = False,
use_scale_shift_norm: bool = False,
dims: int = 2,
use_checkpoint: bool = False,
up: bool = False,
down: bool = False,
dtype=None,
device=None,
operations=ops
):
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,
dtype=dtype,
device=device,
operations=operations
)
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,
dtype=dtype,
device=device,
operations=operations
)
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 = 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 Timestep(nn.Module):
def __init__(self, dim):
super().__init__()
self.dim = dim
def forward(self, t):
return timestep_embedding(t, self.dim)
def apply_control(h, control, name):
if control is not None and name in control and len(control[name]) > 0:
ctrl = control[name].pop()
if ctrl is not None:
try:
h += ctrl
except:
logging.warning("warning control could not be applied {} {}".format(h.shape, ctrl.shape))
return h
class UNetModel(nn.Module):
"""
The full UNet model with attention and timestep embedding.
:param in_channels: 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 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,
image_size,
in_channels,
model_channels,
out_channels,
num_res_blocks,
dropout=0,
channel_mult=(1, 2, 4, 8),
conv_resample=True,
dims=2,
num_classes=None,
use_checkpoint=False,
dtype=th.float32,
num_heads=-1,
num_head_channels=-1,
num_heads_upsample=-1,
use_scale_shift_norm=False,
resblock_updown=False,
use_new_attention_order=False,
use_spatial_transformer=False, # custom transformer support
transformer_depth=1, # custom transformer support
context_dim=None, # custom transformer support
n_embed=None, # custom support for prediction of discrete ids into codebook of first stage vq model
legacy=True,
disable_self_attentions=None,
num_attention_blocks=None,
disable_middle_self_attn=False,
use_linear_in_transformer=False,
adm_in_channels=None,
transformer_depth_middle=None,
transformer_depth_output=None,
use_temporal_resblock=False,
use_temporal_attention=False,
time_context_dim=None,
extra_ff_mix_layer=False,
use_spatial_context=False,
merge_strategy=None,
merge_factor=0.0,
video_kernel_size=None,
disable_temporal_crossattention=False,
max_ddpm_temb_period=10000,
attn_precision=None,
device=None,
operations=ops,
):
super().__init__()
if context_dim is not None:
assert use_spatial_transformer, 'Fool!! You forgot to use the spatial transformer for your cross-attention conditioning...'
# from omegaconf.listconfig import ListConfig
# if type(context_dim) == ListConfig:
# context_dim = list(context_dim)
if num_heads_upsample == -1:
num_heads_upsample = num_heads
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
if isinstance(num_res_blocks, int):
self.num_res_blocks = len(channel_mult) * [num_res_blocks]
else:
if len(num_res_blocks) != len(channel_mult):
raise ValueError("provide num_res_blocks either as an int (globally constant) or "
"as a list/tuple (per-level) with the same length as channel_mult")
self.num_res_blocks = num_res_blocks
if disable_self_attentions is not None:
# should be a list of booleans, indicating whether to disable self-attention in TransformerBlocks or not
assert len(disable_self_attentions) == len(channel_mult)
if num_attention_blocks is not None:
assert len(num_attention_blocks) == len(self.num_res_blocks)
transformer_depth = transformer_depth[:]
transformer_depth_output = transformer_depth_output[:]
self.dropout = dropout
self.channel_mult = channel_mult
self.conv_resample = conv_resample
self.num_classes = num_classes
self.use_checkpoint = use_checkpoint
self.dtype = dtype
self.num_heads = num_heads
self.num_head_channels = num_head_channels
self.num_heads_upsample = num_heads_upsample
self.use_temporal_resblocks = use_temporal_resblock
self.predict_codebook_ids = n_embed is not None
self.default_num_video_frames = None
time_embed_dim = model_channels * 4
self.time_embed = nn.Sequential(
operations.Linear(model_channels, time_embed_dim, dtype=self.dtype, device=device),
nn.SiLU(),
operations.Linear(time_embed_dim, time_embed_dim, dtype=self.dtype, device=device),
)
if self.num_classes is not None:
if isinstance(self.num_classes, int):
self.label_emb = nn.Embedding(num_classes, time_embed_dim, dtype=self.dtype, device=device)
elif self.num_classes == "continuous":
logging.debug("setting up linear c_adm embedding layer")
self.label_emb = nn.Linear(1, time_embed_dim)
elif self.num_classes == "sequential":
assert adm_in_channels is not None
self.label_emb = nn.Sequential(
nn.Sequential(
operations.Linear(adm_in_channels, time_embed_dim, dtype=self.dtype, device=device),
nn.SiLU(),
operations.Linear(time_embed_dim, time_embed_dim, dtype=self.dtype, device=device),
)
)
else:
raise ValueError()
self.input_blocks = nn.ModuleList(
[
TimestepEmbedSequential(
operations.conv_nd(dims, in_channels, model_channels, 3, padding=1, dtype=self.dtype, device=device)
)
]
)
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,
disable_self_attn=False,
):
if use_temporal_attention:
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,
disable_self_attn=disable_self_attn,
disable_temporal_crossattention=disable_temporal_crossattention,
max_time_embed_period=max_ddpm_temb_period,
attn_precision=attn_precision,
dtype=self.dtype, device=device, operations=operations
)
else:
return SpatialTransformer(
ch, num_heads, dim_head, depth=depth, context_dim=context_dim,
disable_self_attn=disable_self_attn, use_linear=use_linear_in_transformer,
use_checkpoint=use_checkpoint, attn_precision=attn_precision, dtype=self.dtype, device=device, operations=operations
)
def get_resblock(
merge_factor,
merge_strategy,
video_kernel_size,
ch,
time_embed_dim,
dropout,
out_channels,
dims,
use_checkpoint,
use_scale_shift_norm,
down=False,
up=False,
dtype=None,
device=None,
operations=ops
):
if self.use_temporal_resblocks:
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_channels,
dims=dims,
use_checkpoint=use_checkpoint,
use_scale_shift_norm=use_scale_shift_norm,
down=down,
up=up,
dtype=dtype,
device=device,
operations=operations
)
else:
return ResBlock(
channels=ch,
emb_channels=time_embed_dim,
dropout=dropout,
out_channels=out_channels,
use_checkpoint=use_checkpoint,
dims=dims,
use_scale_shift_norm=use_scale_shift_norm,
down=down,
up=up,
dtype=dtype,
device=device,
operations=operations
)
for level, mult in enumerate(channel_mult):
for nr in range(self.num_res_blocks[level]):
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_channels=mult * model_channels,
dims=dims,
use_checkpoint=use_checkpoint,
use_scale_shift_norm=use_scale_shift_norm,
dtype=self.dtype,
device=device,
operations=operations,
)
]
ch = mult * model_channels
num_transformers = transformer_depth.pop(0)
if num_transformers > 0:
if num_head_channels == -1:
dim_head = ch // num_heads
else:
num_heads = ch // num_head_channels
dim_head = num_head_channels
if legacy:
#num_heads = 1
dim_head = ch // num_heads if use_spatial_transformer else num_head_channels
if exists(disable_self_attentions):
disabled_sa = disable_self_attentions[level]
else:
disabled_sa = False
if not exists(num_attention_blocks) or nr < num_attention_blocks[level]:
layers.append(get_attention_layer(
ch, num_heads, dim_head, depth=num_transformers, context_dim=context_dim,
disable_self_attn=disabled_sa, use_checkpoint=use_checkpoint)
)
self.input_blocks.append(TimestepEmbedSequential(*layers))
self._feature_size += ch
input_block_chans.append(ch)
if level != len(channel_mult) - 1:
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_channels=out_ch,
dims=dims,
use_checkpoint=use_checkpoint,
use_scale_shift_norm=use_scale_shift_norm,
down=True,
dtype=self.dtype,
device=device,
operations=operations
)
if resblock_updown
else Downsample(
ch, conv_resample, dims=dims, out_channels=out_ch, dtype=self.dtype, device=device, operations=operations
)
)
)
ch = out_ch
input_block_chans.append(ch)
ds *= 2
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
if legacy:
#num_heads = 1
dim_head = ch // num_heads if use_spatial_transformer else num_head_channels
mid_block = [
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_channels=None,
dims=dims,
use_checkpoint=use_checkpoint,
use_scale_shift_norm=use_scale_shift_norm,
dtype=self.dtype,
device=device,
operations=operations
)]
self.middle_block = None
if transformer_depth_middle >= -1:
if transformer_depth_middle >= 0:
mid_block += [get_attention_layer( # always uses a self-attn
ch, num_heads, dim_head, depth=transformer_depth_middle, context_dim=context_dim,
disable_self_attn=disable_middle_self_attn, use_checkpoint=use_checkpoint
),
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_channels=None,
dims=dims,
use_checkpoint=use_checkpoint,
use_scale_shift_norm=use_scale_shift_norm,
dtype=self.dtype,
device=device,
operations=operations
)]
self.middle_block = TimestepEmbedSequential(*mid_block)
self._feature_size += ch
self.output_blocks = nn.ModuleList([])
for level, mult in list(enumerate(channel_mult))[::-1]:
for i in range(self.num_res_blocks[level] + 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_channels=model_channels * mult,
dims=dims,
use_checkpoint=use_checkpoint,
use_scale_shift_norm=use_scale_shift_norm,
dtype=self.dtype,
device=device,
operations=operations
)
]
ch = model_channels * mult
num_transformers = transformer_depth_output.pop()
if num_transformers > 0:
if num_head_channels == -1:
dim_head = ch // num_heads
else:
num_heads = ch // num_head_channels
dim_head = num_head_channels
if legacy:
#num_heads = 1
dim_head = ch // num_heads if use_spatial_transformer else num_head_channels
if exists(disable_self_attentions):
disabled_sa = disable_self_attentions[level]
else:
disabled_sa = False
if not exists(num_attention_blocks) or i < num_attention_blocks[level]:
layers.append(
get_attention_layer(
ch, num_heads, dim_head, depth=num_transformers, context_dim=context_dim,
disable_self_attn=disabled_sa, use_checkpoint=use_checkpoint
)
)
if level and i == self.num_res_blocks[level]:
out_ch = ch
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_channels=out_ch,
dims=dims,
use_checkpoint=use_checkpoint,
use_scale_shift_norm=use_scale_shift_norm,
up=True,
dtype=self.dtype,
device=device,
operations=operations
)
if resblock_updown
else Upsample(ch, conv_resample, dims=dims, out_channels=out_ch, dtype=self.dtype, device=device, operations=operations)
)
ds //= 2
self.output_blocks.append(TimestepEmbedSequential(*layers))
self._feature_size += ch
self.out = nn.Sequential(
operations.GroupNorm(32, ch, dtype=self.dtype, device=device),
nn.SiLU(),
operations.conv_nd(dims, model_channels, out_channels, 3, padding=1, dtype=self.dtype, device=device),
)
if self.predict_codebook_ids:
self.id_predictor = nn.Sequential(
operations.GroupNorm(32, ch, dtype=self.dtype, device=device),
operations.conv_nd(dims, model_channels, n_embed, 1, dtype=self.dtype, device=device),
#nn.LogSoftmax(dim=1) # change to cross_entropy and produce non-normalized logits
)
def forward(self, x, timesteps=None, context=None, y=None, control=None, transformer_options={}, **kwargs):
return comfy.patcher_extension.WrapperExecutor.new_class_executor(
self._forward,
self,
comfy.patcher_extension.get_all_wrappers(comfy.patcher_extension.WrappersMP.DIFFUSION_MODEL, transformer_options)
).execute(x, timesteps, context, y, control, transformer_options, **kwargs)
def _forward(self, x, timesteps=None, context=None, y=None, control=None, transformer_options={}, **kwargs):
"""
Apply the model to an input batch.
:param x: an [N x C x ...] Tensor of inputs.
:param timesteps: a 1-D batch of timesteps.
:param context: conditioning plugged in via crossattn
:param y: an [N] Tensor of labels, if class-conditional.
:return: an [N x C x ...] Tensor of outputs.
"""
transformer_options["original_shape"] = list(x.shape)
transformer_options["transformer_index"] = 0
transformer_patches = transformer_options.get("patches", {})
num_video_frames = kwargs.get("num_video_frames", self.default_num_video_frames)
image_only_indicator = kwargs.get("image_only_indicator", None)
time_context = kwargs.get("time_context", None)
assert (y is not None) == (
self.num_classes is not None
), "must specify y if and only if the model is class-conditional"
hs = []
t_emb = timestep_embedding(timesteps, self.model_channels, repeat_only=False).to(x.dtype)
emb = self.time_embed(t_emb)
if "emb_patch" in transformer_patches:
patch = transformer_patches["emb_patch"]
for p in patch:
emb = p(emb, self.model_channels, transformer_options)
if self.num_classes is not None:
assert y.shape[0] == x.shape[0]
emb = emb + self.label_emb(y)
h = x
for id, module in enumerate(self.input_blocks):
transformer_options["block"] = ("input", id)
h = forward_timestep_embed(module, h, emb, context, transformer_options, time_context=time_context, num_video_frames=num_video_frames, image_only_indicator=image_only_indicator)
h = apply_control(h, control, 'input')
if "input_block_patch" in transformer_patches:
patch = transformer_patches["input_block_patch"]
for p in patch:
h = p(h, transformer_options)
hs.append(h)
if "input_block_patch_after_skip" in transformer_patches:
patch = transformer_patches["input_block_patch_after_skip"]
for p in patch:
h = p(h, transformer_options)
transformer_options["block"] = ("middle", 0)
if self.middle_block is not None:
h = forward_timestep_embed(self.middle_block, h, emb, context, transformer_options, time_context=time_context, num_video_frames=num_video_frames, image_only_indicator=image_only_indicator)
h = apply_control(h, control, 'middle')
for id, module in enumerate(self.output_blocks):
transformer_options["block"] = ("output", id)
hsp = hs.pop()
hsp = apply_control(hsp, control, 'output')
if "output_block_patch" in transformer_patches:
patch = transformer_patches["output_block_patch"]
for p in patch:
h, hsp = p(h, hsp, transformer_options)
h = th.cat([h, hsp], dim=1)
del hsp
if len(hs) > 0:
output_shape = hs[-1].shape
else:
output_shape = None
h = forward_timestep_embed(module, h, emb, context, transformer_options, output_shape, time_context=time_context, num_video_frames=num_video_frames, image_only_indicator=image_only_indicator)
h = h.type(x.dtype)
if self.predict_codebook_ids:
return self.id_predictor(h)
else:
return self.out(h)
import torch
import torch.nn as nn
import numpy as np
from functools import partial
from .util import extract_into_tensor, make_beta_schedule
class AbstractLowScaleModel(nn.Module):
# for concatenating a downsampled image to the latent representation
def __init__(self, noise_schedule_config=None):
super(AbstractLowScaleModel, self).__init__()
if noise_schedule_config is not None:
self.register_schedule(**noise_schedule_config)
def register_schedule(self, beta_schedule="linear", timesteps=1000,
linear_start=1e-4, linear_end=2e-2, cosine_s=8e-3):
betas = make_beta_schedule(beta_schedule, timesteps, linear_start=linear_start, linear_end=linear_end,
cosine_s=cosine_s)
alphas = 1. - betas
alphas_cumprod = np.cumprod(alphas, axis=0)
alphas_cumprod_prev = np.append(1., alphas_cumprod[:-1])
timesteps, = betas.shape
self.num_timesteps = int(timesteps)
self.linear_start = linear_start
self.linear_end = linear_end
assert alphas_cumprod.shape[0] == self.num_timesteps, 'alphas have to be defined for each timestep'
to_torch = partial(torch.tensor, dtype=torch.float32)
self.register_buffer('betas', to_torch(betas))
self.register_buffer('alphas_cumprod', to_torch(alphas_cumprod))
self.register_buffer('alphas_cumprod_prev', to_torch(alphas_cumprod_prev))
# calculations for diffusion q(x_t | x_{t-1}) and others
self.register_buffer('sqrt_alphas_cumprod', to_torch(np.sqrt(alphas_cumprod)))
self.register_buffer('sqrt_one_minus_alphas_cumprod', to_torch(np.sqrt(1. - alphas_cumprod)))
self.register_buffer('log_one_minus_alphas_cumprod', to_torch(np.log(1. - alphas_cumprod)))
self.register_buffer('sqrt_recip_alphas_cumprod', to_torch(np.sqrt(1. / alphas_cumprod)))
self.register_buffer('sqrt_recipm1_alphas_cumprod', to_torch(np.sqrt(1. / alphas_cumprod - 1)))
def q_sample(self, x_start, t, noise=None, seed=None):
if noise is None:
if seed is None:
noise = torch.randn_like(x_start)
else:
noise = torch.randn(x_start.size(), dtype=x_start.dtype, layout=x_start.layout, generator=torch.manual_seed(seed)).to(x_start.device)
return (extract_into_tensor(self.sqrt_alphas_cumprod.to(x_start.device), t, x_start.shape) * x_start +
extract_into_tensor(self.sqrt_one_minus_alphas_cumprod.to(x_start.device), t, x_start.shape) * noise)
def forward(self, x):
return x, None
def decode(self, x):
return x
class SimpleImageConcat(AbstractLowScaleModel):
# no noise level conditioning
def __init__(self):
super(SimpleImageConcat, self).__init__(noise_schedule_config=None)
self.max_noise_level = 0
def forward(self, x):
# fix to constant noise level
return x, torch.zeros(x.shape[0], device=x.device).long()
class ImageConcatWithNoiseAugmentation(AbstractLowScaleModel):
def __init__(self, noise_schedule_config, max_noise_level=1000, to_cuda=False):
super().__init__(noise_schedule_config=noise_schedule_config)
self.max_noise_level = max_noise_level
def forward(self, x, noise_level=None, seed=None):
if noise_level is None:
noise_level = torch.randint(0, self.max_noise_level, (x.shape[0],), device=x.device).long()
else:
assert isinstance(noise_level, torch.Tensor)
z = self.q_sample(x, noise_level, seed=seed)
return z, noise_level
# adopted from
# https://github.com/openai/improved-diffusion/blob/main/improved_diffusion/gaussian_diffusion.py
# and
# https://github.com/lucidrains/denoising-diffusion-pytorch/blob/7706bdfc6f527f58d33f84b7b522e61e6e3164b3/denoising_diffusion_pytorch/denoising_diffusion_pytorch.py
# and
# https://github.com/openai/guided-diffusion/blob/0ba878e517b276c45d1195eb29f6f5f72659a05b/guided_diffusion/nn.py
#
# thanks!
import math
import logging
import torch
import torch.nn as nn
import numpy as np
from einops import repeat, rearrange
from comfy.ldm.util import instantiate_from_config
class AlphaBlender(nn.Module):
strategies = ["learned", "fixed", "learned_with_images"]
def __init__(
self,
alpha: float,
merge_strategy: str = "learned_with_images",
rearrange_pattern: str = "b t -> (b t) 1 1",
):
super().__init__()
self.merge_strategy = merge_strategy
self.rearrange_pattern = rearrange_pattern
assert (
merge_strategy in self.strategies
), f"merge_strategy needs to be in {self.strategies}"
if self.merge_strategy == "fixed":
self.register_buffer("mix_factor", torch.Tensor([alpha]))
elif (
self.merge_strategy == "learned"
or self.merge_strategy == "learned_with_images"
):
self.register_parameter(
"mix_factor", torch.nn.Parameter(torch.Tensor([alpha]))
)
else:
raise ValueError(f"unknown merge strategy {self.merge_strategy}")
def get_alpha(self, image_only_indicator: torch.Tensor, device) -> torch.Tensor:
# skip_time_mix = rearrange(repeat(skip_time_mix, 'b -> (b t) () () ()', t=t), '(b t) 1 ... -> b 1 t ...', t=t)
if self.merge_strategy == "fixed":
# make shape compatible
# alpha = repeat(self.mix_factor, '1 -> b () t () ()', t=t, b=bs)
alpha = self.mix_factor.to(device)
elif self.merge_strategy == "learned":
alpha = torch.sigmoid(self.mix_factor.to(device))
# make shape compatible
# alpha = repeat(alpha, '1 -> s () ()', s = t * bs)
elif self.merge_strategy == "learned_with_images":
if image_only_indicator is None:
alpha = rearrange(torch.sigmoid(self.mix_factor.to(device)), "... -> ... 1")
else:
alpha = torch.where(
image_only_indicator.bool(),
torch.ones(1, 1, device=image_only_indicator.device),
rearrange(torch.sigmoid(self.mix_factor.to(image_only_indicator.device)), "... -> ... 1"),
)
alpha = rearrange(alpha, self.rearrange_pattern)
# make shape compatible
# alpha = repeat(alpha, '1 -> s () ()', s = t * bs)
else:
raise NotImplementedError()
return alpha
def forward(
self,
x_spatial,
x_temporal,
image_only_indicator=None,
) -> torch.Tensor:
alpha = self.get_alpha(image_only_indicator, x_spatial.device)
x = (
alpha.to(x_spatial.dtype) * x_spatial
+ (1.0 - alpha).to(x_spatial.dtype) * x_temporal
)
return x
def make_beta_schedule(schedule, n_timestep, linear_start=1e-4, linear_end=2e-2, cosine_s=8e-3):
if schedule == "linear":
betas = (
torch.linspace(linear_start ** 0.5, linear_end ** 0.5, n_timestep, dtype=torch.float64) ** 2
)
elif schedule == "cosine":
timesteps = (
torch.arange(n_timestep + 1, dtype=torch.float64) / n_timestep + cosine_s
)
alphas = timesteps / (1 + cosine_s) * np.pi / 2
alphas = torch.cos(alphas).pow(2)
alphas = alphas / alphas[0]
betas = 1 - alphas[1:] / alphas[:-1]
betas = torch.clamp(betas, min=0, max=0.999)
elif schedule == "squaredcos_cap_v2": # used for karlo prior
# return early
return betas_for_alpha_bar(
n_timestep,
lambda t: math.cos((t + 0.008) / 1.008 * math.pi / 2) ** 2,
)
elif schedule == "sqrt_linear":
betas = torch.linspace(linear_start, linear_end, n_timestep, dtype=torch.float64)
elif schedule == "sqrt":
betas = torch.linspace(linear_start, linear_end, n_timestep, dtype=torch.float64) ** 0.5
else:
raise ValueError(f"schedule '{schedule}' unknown.")
return betas
def make_ddim_timesteps(ddim_discr_method, num_ddim_timesteps, num_ddpm_timesteps, verbose=True):
if ddim_discr_method == 'uniform':
c = num_ddpm_timesteps // num_ddim_timesteps
ddim_timesteps = np.asarray(list(range(0, num_ddpm_timesteps, c)))
elif ddim_discr_method == 'quad':
ddim_timesteps = ((np.linspace(0, np.sqrt(num_ddpm_timesteps * .8), num_ddim_timesteps)) ** 2).astype(int)
else:
raise NotImplementedError(f'There is no ddim discretization method called "{ddim_discr_method}"')
# assert ddim_timesteps.shape[0] == num_ddim_timesteps
# add one to get the final alpha values right (the ones from first scale to data during sampling)
steps_out = ddim_timesteps + 1
if verbose:
logging.info(f'Selected timesteps for ddim sampler: {steps_out}')
return steps_out
def make_ddim_sampling_parameters(alphacums, ddim_timesteps, eta, verbose=True):
# select alphas for computing the variance schedule
alphas = alphacums[ddim_timesteps]
alphas_prev = np.asarray([alphacums[0]] + alphacums[ddim_timesteps[:-1]].tolist())
# according the the formula provided in https://arxiv.org/abs/2010.02502
sigmas = eta * np.sqrt((1 - alphas_prev) / (1 - alphas) * (1 - alphas / alphas_prev))
if verbose:
logging.info(f'Selected alphas for ddim sampler: a_t: {alphas}; a_(t-1): {alphas_prev}')
logging.info(f'For the chosen value of eta, which is {eta}, '
f'this results in the following sigma_t schedule for ddim sampler {sigmas}')
return sigmas, alphas, alphas_prev
def betas_for_alpha_bar(num_diffusion_timesteps, alpha_bar, max_beta=0.999):
"""
Create a beta schedule that discretizes the given alpha_t_bar function,
which defines the cumulative product of (1-beta) over time from t = [0,1].
:param num_diffusion_timesteps: the number of betas to produce.
:param alpha_bar: a lambda that takes an argument t from 0 to 1 and
produces the cumulative product of (1-beta) up to that
part of the diffusion process.
:param max_beta: the maximum beta to use; use values lower than 1 to
prevent singularities.
"""
betas = []
for i in range(num_diffusion_timesteps):
t1 = i / num_diffusion_timesteps
t2 = (i + 1) / num_diffusion_timesteps
betas.append(min(1 - alpha_bar(t2) / alpha_bar(t1), max_beta))
return np.array(betas)
def extract_into_tensor(a, t, x_shape):
b, *_ = t.shape
out = a.gather(-1, t)
return out.reshape(b, *((1,) * (len(x_shape) - 1)))
def checkpoint(func, inputs, params, flag):
"""
Evaluate a function without caching intermediate activations, allowing for
reduced memory at the expense of extra compute in the backward pass.
:param func: the function to evaluate.
:param inputs: the argument sequence to pass to `func`.
:param params: a sequence of parameters `func` depends on but does not
explicitly take as arguments.
:param flag: if False, disable gradient checkpointing.
"""
if flag:
args = tuple(inputs) + tuple(params)
return CheckpointFunction.apply(func, len(inputs), *args)
else:
return func(*inputs)
class CheckpointFunction(torch.autograd.Function):
@staticmethod
def forward(ctx, run_function, length, *args):
ctx.run_function = run_function
ctx.input_tensors = list(args[:length])
ctx.input_params = list(args[length:])
ctx.gpu_autocast_kwargs = {"enabled": torch.is_autocast_enabled(),
"dtype": torch.get_autocast_gpu_dtype(),
"cache_enabled": torch.is_autocast_cache_enabled()}
with torch.no_grad():
output_tensors = ctx.run_function(*ctx.input_tensors)
return output_tensors
@staticmethod
def backward(ctx, *output_grads):
ctx.input_tensors = [x.detach().requires_grad_(True) for x in ctx.input_tensors]
with torch.enable_grad(), \
torch.cuda.amp.autocast(**ctx.gpu_autocast_kwargs):
# Fixes a bug where the first op in run_function modifies the
# Tensor storage in place, which is not allowed for detach()'d
# Tensors.
shallow_copies = [x.view_as(x) for x in ctx.input_tensors]
output_tensors = ctx.run_function(*shallow_copies)
input_grads = torch.autograd.grad(
output_tensors,
ctx.input_tensors + ctx.input_params,
output_grads,
allow_unused=True,
)
del ctx.input_tensors
del ctx.input_params
del output_tensors
return (None, None) + input_grads
def timestep_embedding(timesteps, dim, max_period=10000, repeat_only=False):
"""
Create sinusoidal timestep embeddings.
:param timesteps: a 1-D Tensor of N indices, one per batch element.
These may be fractional.
:param dim: the dimension of the output.
:param max_period: controls the minimum frequency of the embeddings.
:return: an [N x dim] Tensor of positional embeddings.
"""
if not repeat_only:
half = dim // 2
freqs = torch.exp(
-math.log(max_period) * torch.arange(start=0, end=half, dtype=torch.float32, device=timesteps.device) / half
)
args = timesteps[:, None].float() * freqs[None]
embedding = torch.cat([torch.cos(args), torch.sin(args)], dim=-1)
if dim % 2:
embedding = torch.cat([embedding, torch.zeros_like(embedding[:, :1])], dim=-1)
else:
embedding = repeat(timesteps, 'b -> b d', d=dim)
return embedding
def zero_module(module):
"""
Zero out the parameters of a module and return it.
"""
for p in module.parameters():
p.detach().zero_()
return module
def scale_module(module, scale):
"""
Scale the parameters of a module and return it.
"""
for p in module.parameters():
p.detach().mul_(scale)
return module
def mean_flat(tensor):
"""
Take the mean over all non-batch dimensions.
"""
return tensor.mean(dim=list(range(1, len(tensor.shape))))
def avg_pool_nd(dims, *args, **kwargs):
"""
Create a 1D, 2D, or 3D average pooling module.
"""
if dims == 1:
return nn.AvgPool1d(*args, **kwargs)
elif dims == 2:
return nn.AvgPool2d(*args, **kwargs)
elif dims == 3:
return nn.AvgPool3d(*args, **kwargs)
raise ValueError(f"unsupported dimensions: {dims}")
class HybridConditioner(nn.Module):
def __init__(self, c_concat_config, c_crossattn_config):
super().__init__()
self.concat_conditioner = instantiate_from_config(c_concat_config)
self.crossattn_conditioner = instantiate_from_config(c_crossattn_config)
def forward(self, c_concat, c_crossattn):
c_concat = self.concat_conditioner(c_concat)
c_crossattn = self.crossattn_conditioner(c_crossattn)
return {'c_concat': [c_concat], 'c_crossattn': [c_crossattn]}
def noise_like(shape, device, repeat=False):
repeat_noise = lambda: torch.randn((1, *shape[1:]), device=device).repeat(shape[0], *((1,) * (len(shape) - 1)))
noise = lambda: torch.randn(shape, device=device)
return repeat_noise() if repeat else noise()
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