This commit is contained in:
Haoming
2026-01-30 11:02:24 +08:00
parent 9e6599f7f6
commit fb5cbd8063
+196 -234
View File
@@ -1,6 +1,4 @@
# implementation of Chroma for Forge
# Credit: croquelois
# Reference: https://github.com/lodestone-rock/ComfyUI_FluxMod
# https://github.com/Comfy-Org/ComfyUI/tree/v0.10.0/comfy/ldm/chroma
from dataclasses import dataclass
@@ -9,26 +7,40 @@ from einops import rearrange, repeat
from torch import nn
from backend.nn.flux import (
DoubleStreamBlock,
EmbedND,
MLPEmbedder,
QKNorm,
ModulationOut,
RMSNorm,
SelfAttention,
attention,
SingleStreamBlock,
timestep_embedding,
)
from backend.utils import fp16_fix
from backend.utils import fp16_fix, pad_to_patch_size
class ChromaModulationOut(ModulationOut):
@classmethod
def from_offset(cls, tensor: torch.Tensor, offset: int = 0) -> ModulationOut:
return cls(
shift=tensor[:, offset : offset + 1, :],
scale=tensor[:, offset + 1 : offset + 2, :],
gate=tensor[:, offset + 2 : offset + 3, :],
)
class Approximator(nn.Module):
def __init__(self, in_dim: int, out_dim: int, hidden_dim: int, n_layers=4):
def __init__(self, in_dim: int, out_dim: int, hidden_dim: int, n_layers=5):
super().__init__()
self.in_proj = nn.Linear(in_dim, hidden_dim, bias=True)
self.layers = nn.ModuleList([MLPEmbedder(hidden_dim, hidden_dim) for x in range(n_layers)])
self.norms = nn.ModuleList([RMSNorm(hidden_dim) for x in range(n_layers)])
self.layers = nn.ModuleList([MLPEmbedder(hidden_dim, hidden_dim) for _ in range(n_layers)])
self.norms = nn.ModuleList([RMSNorm(hidden_dim) for _ in range(n_layers)])
self.out_proj = nn.Linear(hidden_dim, out_dim)
def forward(self, x):
@property
def device(self):
return next(self.parameters()).device
def forward(self, x: torch.Tensor) -> torch.Tensor:
x = self.in_proj(x)
for layer, norms in zip(self.layers, self.norms):
x = x + layer(norms(x))
@@ -36,105 +48,14 @@ class Approximator(nn.Module):
return x
@dataclass
class ModulationOut:
shift: torch.Tensor
scale: torch.Tensor
gate: torch.Tensor
class DoubleStreamBlock(nn.Module):
def __init__(self, hidden_size, num_heads, mlp_ratio, qkv_bias=False):
super().__init__()
mlp_hidden_dim = int(hidden_size * mlp_ratio)
self.num_heads = num_heads
self.hidden_size = hidden_size
self.img_norm1 = nn.LayerNorm(hidden_size, elementwise_affine=False, eps=1e-6)
self.img_attn = SelfAttention(dim=hidden_size, num_heads=num_heads, qkv_bias=qkv_bias)
self.img_norm2 = nn.LayerNorm(hidden_size, elementwise_affine=False, eps=1e-6)
self.img_mlp = nn.Sequential(
nn.Linear(hidden_size, mlp_hidden_dim, bias=True),
nn.GELU(approximate="tanh"),
nn.Linear(mlp_hidden_dim, hidden_size, bias=True),
)
self.txt_norm1 = nn.LayerNorm(hidden_size, elementwise_affine=False, eps=1e-6)
self.txt_attn = SelfAttention(dim=hidden_size, num_heads=num_heads, qkv_bias=qkv_bias)
self.txt_norm2 = nn.LayerNorm(hidden_size, elementwise_affine=False, eps=1e-6)
self.txt_mlp = nn.Sequential(
nn.Linear(hidden_size, mlp_hidden_dim, bias=True),
nn.GELU(approximate="tanh"),
nn.Linear(mlp_hidden_dim, hidden_size, bias=True),
)
def forward(self, img: torch.Tensor, txt: torch.Tensor, mod: torch.Tensor, pe: torch.Tensor, attn_mask=None, transformer_options={}):
(img_mod1, img_mod2), (txt_mod1, txt_mod2) = mod
img_modulated = torch.addcmul(img_mod1.shift, 1 + img_mod1.scale, self.img_norm1(img))
img_qkv = self.img_attn.qkv(img_modulated)
img_q, img_k, img_v = img_qkv.view(img_qkv.shape[0], img_qkv.shape[1], 3, self.num_heads, -1).permute(2, 0, 3, 1, 4)
img_q, img_k = self.img_attn.norm(img_q, img_k, img_v)
txt_modulated = torch.addcmul(txt_mod1.shift, 1 + txt_mod1.scale, self.txt_norm1(txt))
txt_qkv = self.txt_attn.qkv(txt_modulated)
txt_q, txt_k, txt_v = txt_qkv.view(txt_qkv.shape[0], txt_qkv.shape[1], 3, self.num_heads, -1).permute(2, 0, 3, 1, 4)
txt_q, txt_k = self.txt_attn.norm(txt_q, txt_k, txt_v)
attn = attention(
torch.cat((txt_q, img_q), dim=2),
torch.cat((txt_k, img_k), dim=2),
torch.cat((txt_v, img_v), dim=2),
pe=pe,
mask=attn_mask,
transformer_options=transformer_options,
)
txt_attn, img_attn = attn[:, : txt.shape[1]], attn[:, txt.shape[1] :]
img.addcmul_(img_mod1.gate, self.img_attn.proj(img_attn))
img.addcmul_(img_mod2.gate, self.img_mlp(torch.addcmul(img_mod2.shift, 1 + img_mod2.scale, self.img_norm2(img))))
txt.addcmul_(txt_mod1.gate, self.txt_attn.proj(txt_attn))
txt.addcmul_(txt_mod2.gate, self.txt_mlp(torch.addcmul(txt_mod2.shift, 1 + txt_mod2.scale, self.txt_norm2(txt))))
return img, fp16_fix(txt)
class SingleStreamBlock(nn.Module):
def __init__(self, hidden_size, num_heads, mlp_ratio=4.0, qk_scale=None):
super().__init__()
self.hidden_dim = hidden_size
self.num_heads = num_heads
head_dim = hidden_size // num_heads
self.scale = qk_scale or head_dim**-0.5
self.mlp_hidden_dim = int(hidden_size * mlp_ratio)
self.linear1 = nn.Linear(hidden_size, hidden_size * 3 + self.mlp_hidden_dim)
self.linear2 = nn.Linear(hidden_size + self.mlp_hidden_dim, hidden_size)
self.norm = QKNorm(head_dim)
self.hidden_size = hidden_size
self.pre_norm = nn.LayerNorm(hidden_size, elementwise_affine=False, eps=1e-6)
self.mlp_act = nn.GELU(approximate="tanh")
def forward(self, x: torch.Tensor, mod: torch.Tensor, pe: torch.Tensor, attn_mask=None, transformer_options={}) -> torch.Tensor:
x_mod = torch.addcmul(mod.shift, 1 + mod.scale, self.pre_norm(x))
qkv, mlp = torch.split(self.linear1(x_mod), [3 * self.hidden_size, self.mlp_hidden_dim], dim=-1)
q, k, v = qkv.view(qkv.shape[0], qkv.shape[1], 3, self.num_heads, -1).permute(2, 0, 3, 1, 4)
q, k = self.norm(q, k, v)
attn = attention(q, k, v, pe=pe, mask=attn_mask, transformer_options=transformer_options)
output = self.linear2(torch.cat((attn, self.mlp_act(mlp)), 2))
x.addcmul_(mod.gate, output)
return fp16_fix(x)
class LastLayer(nn.Module):
def __init__(self, hidden_size, patch_size, out_channels):
def __init__(self, hidden_size: int, patch_size: int, out_channels: int):
super().__init__()
self.norm_final = nn.LayerNorm(hidden_size, elementwise_affine=False, eps=1e-6)
self.linear = nn.Linear(hidden_size, patch_size * patch_size * out_channels, bias=True)
self.linear = nn.Linear(hidden_size, out_channels, bias=True)
def forward(self, x: torch.Tensor, mod: torch.Tensor) -> torch.Tensor:
shift, scale = mod
def forward(self, x: torch.Tensor, vec: torch.Tensor) -> torch.Tensor:
shift, scale = vec
shift = shift.squeeze(1)
scale = scale.squeeze(1)
x = torch.addcmul(shift[:, None, :], 1 + scale[:, None, :], self.norm_final(x))
@@ -142,160 +63,201 @@ class LastLayer(nn.Module):
return x
@dataclass
class ChromaParams:
in_channels: int
out_channels: int
context_in_dim: int
hidden_size: int
mlp_ratio: float
num_heads: int
depth: int
depth_single_blocks: int
axes_dim: list
theta: int
patch_size: int
qkv_bias: bool
in_dim: int
out_dim: int
hidden_dim: int
n_layers: int
txt_ids_dims: list
vec_in_dim: int
class IntegratedChromaTransformer2DModel(nn.Module):
def __init__(self, in_channels: int, out_channels: int, context_in_dim: int, hidden_size: int, mlp_ratio: float, num_heads: int, depth: int, depth_single_blocks: int, axes_dim: list[int], theta: int, patch_size: int, qkv_bias: bool, in_dim: int, out_dim: int, hidden_dim: int, n_layers: int):
def __init__(self, **kwargs):
super().__init__()
params = ChromaParams(**kwargs)
self.params = params
self.patch_size = patch_size
self.in_channels = in_channels
self.out_channels = out_channels
if hidden_size % num_heads != 0:
raise ValueError(f"Hidden size {hidden_size} must be divisible by num_heads {num_heads}")
pe_dim = hidden_size // num_heads
if sum(axes_dim) != pe_dim:
raise ValueError(f"Got {axes_dim} but expected positional dim {pe_dim}")
self.hidden_size = hidden_size
self.num_heads = num_heads
self.pe_embedder = EmbedND(dim=pe_dim, theta=theta, axes_dim=axes_dim)
self.patch_size = params.patch_size
self.in_channels = params.in_channels
self.out_channels = params.out_channels
if params.hidden_size % params.num_heads != 0:
raise ValueError(f"Hidden size {params.hidden_size} must be divisible by num_heads {params.num_heads}")
pe_dim = params.hidden_size // params.num_heads
if sum(params.axes_dim) != pe_dim:
raise ValueError(f"Got {params.axes_dim} but expected positional dim {pe_dim}")
self.hidden_size = params.hidden_size
self.num_heads = params.num_heads
self.in_dim = params.in_dim
self.out_dim = params.out_dim
self.hidden_dim = params.hidden_dim
self.n_layers = params.n_layers
self.pe_embedder = EmbedND(dim=pe_dim, theta=params.theta, axes_dim=params.axes_dim)
self.img_in = nn.Linear(self.in_channels, self.hidden_size, bias=True)
self.distilled_guidance_layer = Approximator(in_dim, out_dim, hidden_dim, n_layers)
self.txt_in = nn.Linear(context_in_dim, self.hidden_size)
self.txt_in = nn.Linear(params.context_in_dim, self.hidden_size)
self.double_blocks = nn.ModuleList(
[
DoubleStreamBlock(
self.hidden_size,
self.num_heads,
mlp_ratio=mlp_ratio,
qkv_bias=qkv_bias,
)
for _ in range(depth)
]
)
self.distilled_guidance_layer = Approximator(in_dim=self.in_dim, hidden_dim=self.hidden_dim, out_dim=self.out_dim, n_layers=self.n_layers)
self.single_blocks = nn.ModuleList(
[
SingleStreamBlock(
self.hidden_size,
self.num_heads,
mlp_ratio=mlp_ratio,
)
for _ in range(depth_single_blocks)
]
)
self.double_blocks = nn.ModuleList([DoubleStreamBlock(self.hidden_size, self.num_heads, mlp_ratio=params.mlp_ratio, qkv_bias=params.qkv_bias, modulation=False) for _ in range(params.depth)])
self.single_blocks = nn.ModuleList([SingleStreamBlock(self.hidden_size, self.num_heads, mlp_ratio=params.mlp_ratio, modulation=False) for _ in range(params.depth_single_blocks)])
self.final_layer = LastLayer(self.hidden_size, 1, self.out_channels)
@staticmethod
def distribute_modulations(tensor, single_block_count: int = 38, double_blocks_count: int = 19):
"""
Distributes slices of the tensor into the block_dict as ModulationOut objects.
self.skip_mmdit = []
self.skip_dit = []
self.lite = False
Args:
tensor (torch.Tensor): Input tensor with shape [batch_size, vectors, dim].
"""
block_dict = {}
for i in range(single_block_count):
key = f"single_blocks.{i}.modulation.lin"
block_dict[key] = None
for i in range(double_blocks_count):
key = f"double_blocks.{i}.img_mod.lin"
block_dict[key] = None
for i in range(double_blocks_count):
key = f"double_blocks.{i}.txt_mod.lin"
block_dict[key] = None
block_dict["final_layer.adaLN_modulation.1"] = None
idx = 0 # Index to keep track of the vector slices
for key in block_dict.keys():
if "single_blocks" in key:
# Single block: 1 ModulationOut
block_dict[key] = ModulationOut(shift=tensor[:, idx : idx + 1, :], scale=tensor[:, idx + 1 : idx + 2, :], gate=tensor[:, idx + 2 : idx + 3, :])
idx += 3 # Advance by 3 vectors
elif "img_mod" in key:
# Double block: List of 2 ModulationOut
double_block = []
for _ in range(2): # Create 2 ModulationOut objects
double_block.append(ModulationOut(shift=tensor[:, idx : idx + 1, :], scale=tensor[:, idx + 1 : idx + 2, :], gate=tensor[:, idx + 2 : idx + 3, :]))
idx += 3 # Advance by 3 vectors per ModulationOut
block_dict[key] = double_block
elif "txt_mod" in key:
# Double block: List of 2 ModulationOut
double_block = []
for _ in range(2): # Create 2 ModulationOut objects
double_block.append(ModulationOut(shift=tensor[:, idx : idx + 1, :], scale=tensor[:, idx + 1 : idx + 2, :], gate=tensor[:, idx + 2 : idx + 3, :]))
idx += 3 # Advance by 3 vectors per ModulationOut
block_dict[key] = double_block
elif "final_layer" in key:
# Final layer: 1 ModulationOut
block_dict[key] = [
tensor[:, idx : idx + 1, :],
tensor[:, idx + 1 : idx + 2, :],
]
idx += 2 # Advance by 2 vectors
return block_dict
def get_modulations(self, tensor: torch.Tensor, block_type: str, *, idx: int = 0):
# This function slices up the modulations tensor which has the following layout:
# single : num_single_blocks * 3 elements
# double_img : num_double_blocks * 6 elements
# double_txt : num_double_blocks * 6 elements
# final : 2 elements
if block_type == "final":
return (tensor[:, -2:-1, :], tensor[:, -1:, :])
single_block_count = self.params.depth_single_blocks
double_block_count = self.params.depth
offset = 3 * idx
if block_type == "single":
return ChromaModulationOut.from_offset(tensor, offset)
offset *= 2
if block_type in {"double_img", "double_txt"}:
offset += 3 * single_block_count
if block_type == "double_txt":
offset += 6 * double_block_count
return (
ChromaModulationOut.from_offset(tensor, offset),
ChromaModulationOut.from_offset(tensor, offset + 3),
)
raise ValueError("block_type")
def forward_orig(
self,
img: torch.Tensor,
img_ids: torch.Tensor,
txt: torch.Tensor,
txt_ids: torch.Tensor,
timesteps: torch.Tensor,
guidance: torch.Tensor = None,
control=None,
transformer_options={},
attn_mask: torch.Tensor = None,
) -> torch.Tensor:
patches_replace = transformer_options.get("patches_replace", {})
def inner_forward(self, img, img_ids, txt, txt_ids, timesteps):
if img.ndim != 3 or txt.ndim != 3:
raise ValueError("Input img and txt tensors must have 3 dimensions.")
img = self.img_in(img)
device = img.device
dtype = img.dtype # torch.bfloat16
nb_double_block = len(self.double_blocks)
nb_single_block = len(self.single_blocks)
mod_index_length = nb_double_block * 12 + nb_single_block * 3 + 2
distill_timestep = timestep_embedding(timesteps.detach().clone(), 16).to(device=device, dtype=dtype)
distil_guidance = timestep_embedding(torch.zeros_like(timesteps), 16).to(device=device, dtype=dtype)
modulation_index = timestep_embedding(torch.arange(mod_index_length), 32).to(device=device, dtype=dtype)
modulation_index = modulation_index.unsqueeze(0).repeat(img.shape[0], 1, 1)
timestep_guidance = torch.cat([distill_timestep, distil_guidance], dim=1).unsqueeze(1).repeat(1, mod_index_length, 1)
input_vec = torch.cat([timestep_guidance, modulation_index], dim=-1)
mod_index_length = 344
distill_timestep = timestep_embedding(timesteps.detach().clone(), 16).to(img.device, img.dtype)
distil_guidance = timestep_embedding(guidance.detach().clone(), 16).to(img.device, img.dtype)
modulation_index = timestep_embedding(torch.arange(mod_index_length, device=img.device), 32).to(img.device, img.dtype)
modulation_index = modulation_index.unsqueeze(0).repeat(img.shape[0], 1, 1).to(img.device, img.dtype)
timestep_guidance = torch.cat([distill_timestep, distil_guidance], dim=1).unsqueeze(1).repeat(1, mod_index_length, 1).to(img.dtype).to(img.device, img.dtype)
input_vec = torch.cat([timestep_guidance, modulation_index], dim=-1).to(img.device, img.dtype)
mod_vectors = self.distilled_guidance_layer(input_vec)
mod_vectors_dict = self.distribute_modulations(mod_vectors, nb_single_block, nb_double_block)
txt = self.txt_in(txt)
ids = torch.cat((txt_ids, img_ids), dim=1)
del txt_ids, img_ids
pe = self.pe_embedder(ids)
del ids
blocks_replace = patches_replace.get("dit", {})
transformer_options["total_blocks"] = len(self.double_blocks)
transformer_options["block_type"] = "double"
for i, block in enumerate(self.double_blocks):
img_mod = mod_vectors_dict[f"double_blocks.{i}.img_mod.lin"]
txt_mod = mod_vectors_dict[f"double_blocks.{i}.txt_mod.lin"]
double_mod = [img_mod, txt_mod]
img, txt = block(img=img, txt=txt, mod=double_mod, pe=pe)
transformer_options["block_index"] = i
if i not in self.skip_mmdit:
double_mod = (
self.get_modulations(mod_vectors, "double_img", idx=i),
self.get_modulations(mod_vectors, "double_txt", idx=i),
)
if ("double_block", i) in blocks_replace:
def block_wrap(args):
out = {}
out["img"], out["txt"] = block(img=args["img"], txt=args["txt"], vec=args["vec"], pe=args["pe"], attn_mask=args.get("attn_mask"), transformer_options=args.get("transformer_options"))
return out
out = blocks_replace[("double_block", i)]({"img": img, "txt": txt, "vec": double_mod, "pe": pe, "attn_mask": attn_mask, "transformer_options": transformer_options}, {"original_block": block_wrap})
txt = out["txt"]
img = out["img"]
else:
img, txt = block(img=img, txt=txt, vec=double_mod, pe=pe, attn_mask=attn_mask, transformer_options=transformer_options)
if control is not None: # ControlNet
control_i = control.get("input")
if i < len(control_i):
add = control_i[i]
if add is not None:
img += add
img = fp16_fix(img)
img = torch.cat((txt, img), 1)
transformer_options["total_blocks"] = len(self.single_blocks)
transformer_options["block_type"] = "single"
for i, block in enumerate(self.single_blocks):
single_mod = mod_vectors_dict[f"single_blocks.{i}.modulation.lin"]
img = block(img, mod=single_mod, pe=pe)
del pe
transformer_options["block_index"] = i
if i not in self.skip_dit:
single_mod = self.get_modulations(mod_vectors, "single", idx=i)
if ("single_block", i) in blocks_replace:
def block_wrap(args):
out = {}
out["img"] = block(args["img"], vec=args["vec"], pe=args["pe"], attn_mask=args.get("attn_mask"), transformer_options=args.get("transformer_options"))
return out
out = blocks_replace[("single_block", i)]({"img": img, "vec": single_mod, "pe": pe, "attn_mask": attn_mask, "transformer_options": transformer_options}, {"original_block": block_wrap})
img = out["img"]
else:
img = block(img, vec=single_mod, pe=pe, attn_mask=attn_mask, transformer_options=transformer_options)
if control is not None: # ControlNet
control_o = control.get("output")
if i < len(control_o):
add = control_o[i]
if add is not None:
img[:, txt.shape[1] :, ...] += add
img = img[:, txt.shape[1] :, ...]
final_mod = mod_vectors_dict["final_layer.adaLN_modulation.1"]
img = self.final_layer(img, final_mod)
if hasattr(self, "final_layer"):
final_mod = self.get_modulations(mod_vectors, "final")
img = self.final_layer(img, vec=final_mod)
return img
def forward(self, x: torch.Tensor, timestep, context, **kwargs):
def forward(self, x, timestep, context, guidance=None, control=None, transformer_options={}, **kwargs):
bs, c, h, w = x.shape
input_device = x.device
input_dtype = x.dtype
pad_h = (self.patch_size - x.shape[-2] % self.patch_size) % self.patch_size
pad_w = (self.patch_size - x.shape[-1] % self.patch_size) % self.patch_size
x = torch.nn.functional.pad(x, (0, pad_w, 0, pad_h), mode="circular")
x = pad_to_patch_size(x, (self.patch_size, self.patch_size))
img = rearrange(x, "b c (h ph) (w pw) -> b (h w) (c ph pw)", ph=self.patch_size, pw=self.patch_size)
del x, pad_h, pad_w
if img.ndim != 3 or context.ndim != 3:
raise ValueError("Input img and txt tensors must have 3 dimensions.")
h_len = (h + (self.patch_size // 2)) // self.patch_size
w_len = (w + (self.patch_size // 2)) // self.patch_size
img_ids = torch.zeros((h_len, w_len, 3), device=input_device, dtype=input_dtype)
img_ids[..., 1] = img_ids[..., 1] + torch.linspace(0, h_len - 1, steps=h_len, device=input_device, dtype=input_dtype)[:, None]
img_ids[..., 2] = img_ids[..., 2] + torch.linspace(0, w_len - 1, steps=w_len, device=input_device, dtype=input_dtype)[None, :]
img_ids = torch.zeros((h_len, w_len, 3), device=x.device, dtype=x.dtype)
img_ids[:, :, 1] = img_ids[:, :, 1] + torch.linspace(0, h_len - 1, steps=h_len, device=x.device, dtype=x.dtype).unsqueeze(1)
img_ids[:, :, 2] = img_ids[:, :, 2] + torch.linspace(0, w_len - 1, steps=w_len, device=x.device, dtype=x.dtype).unsqueeze(0)
img_ids = repeat(img_ids, "h w c -> b (h w) c", b=bs)
txt_ids = torch.zeros((bs, context.shape[1], 3), device=input_device, dtype=input_dtype)
del input_device, input_dtype
out = self.inner_forward(img, img_ids, context, txt_ids, timestep)
del img, img_ids, txt_ids, timestep, context
out = rearrange(out, "b (h w) (c ph pw) -> b c (h ph) (w pw)", h=h_len, w=w_len, ph=2, pw=2)[:, :, :h, :w]
del h_len, w_len, bs
return out
txt_ids = torch.zeros((bs, context.shape[1], 3), device=x.device, dtype=x.dtype)
out = self.forward_orig(img, img_ids, context, txt_ids, timestep, guidance or torch.zeros_like(timestep), control, transformer_options, attn_mask=kwargs.get("attention_mask", None))
return rearrange(out, "b (h w) (c ph pw) -> b c (h ph) (w pw)", h=h_len, w=w_len, ph=self.patch_size, pw=self.patch_size)[:, :, :h, :w]