Commit 873911fa authored by fengyf1's avatar fengyf1
Browse files

Initial commit

parents
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
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