Files
DiffSynth-Studio/diffsynth/models/flux_dit.py
2025-12-04 16:33:07 +08:00

396 lines
17 KiB
Python

import torch
from .general_modules import TimestepEmbeddings, AdaLayerNorm, RMSNorm
from einops import rearrange
def interact_with_ipadapter(hidden_states, q, ip_k, ip_v, scale=1.0):
batch_size, num_tokens = hidden_states.shape[0:2]
ip_hidden_states = torch.nn.functional.scaled_dot_product_attention(q, ip_k, ip_v)
ip_hidden_states = ip_hidden_states.transpose(1, 2).reshape(batch_size, num_tokens, -1)
hidden_states = hidden_states + scale * ip_hidden_states
return hidden_states
class RoPEEmbedding(torch.nn.Module):
def __init__(self, dim, theta, axes_dim):
super().__init__()
self.dim = dim
self.theta = theta
self.axes_dim = axes_dim
def rope(self, pos: torch.Tensor, dim: int, theta: int) -> torch.Tensor:
assert dim % 2 == 0, "The dimension must be even."
scale = torch.arange(0, dim, 2, dtype=torch.float64, device=pos.device) / dim
omega = 1.0 / (theta**scale)
batch_size, seq_length = pos.shape
out = torch.einsum("...n,d->...nd", pos, omega)
cos_out = torch.cos(out)
sin_out = torch.sin(out)
stacked_out = torch.stack([cos_out, -sin_out, sin_out, cos_out], dim=-1)
out = stacked_out.view(batch_size, -1, dim // 2, 2, 2)
return out.float()
def forward(self, ids):
n_axes = ids.shape[-1]
emb = torch.cat([self.rope(ids[..., i], self.axes_dim[i], self.theta) for i in range(n_axes)], dim=-3)
return emb.unsqueeze(1)
class FluxJointAttention(torch.nn.Module):
def __init__(self, dim_a, dim_b, num_heads, head_dim, only_out_a=False):
super().__init__()
self.num_heads = num_heads
self.head_dim = head_dim
self.only_out_a = only_out_a
self.a_to_qkv = torch.nn.Linear(dim_a, dim_a * 3)
self.b_to_qkv = torch.nn.Linear(dim_b, dim_b * 3)
self.norm_q_a = RMSNorm(head_dim, eps=1e-6)
self.norm_k_a = RMSNorm(head_dim, eps=1e-6)
self.norm_q_b = RMSNorm(head_dim, eps=1e-6)
self.norm_k_b = RMSNorm(head_dim, eps=1e-6)
self.a_to_out = torch.nn.Linear(dim_a, dim_a)
if not only_out_a:
self.b_to_out = torch.nn.Linear(dim_b, dim_b)
def apply_rope(self, xq, xk, freqs_cis):
xq_ = xq.float().reshape(*xq.shape[:-1], -1, 1, 2)
xk_ = xk.float().reshape(*xk.shape[:-1], -1, 1, 2)
xq_out = freqs_cis[..., 0] * xq_[..., 0] + freqs_cis[..., 1] * xq_[..., 1]
xk_out = freqs_cis[..., 0] * xk_[..., 0] + freqs_cis[..., 1] * xk_[..., 1]
return xq_out.reshape(*xq.shape).type_as(xq), xk_out.reshape(*xk.shape).type_as(xk)
def forward(self, hidden_states_a, hidden_states_b, image_rotary_emb, attn_mask=None, ipadapter_kwargs_list=None):
batch_size = hidden_states_a.shape[0]
# Part A
qkv_a = self.a_to_qkv(hidden_states_a)
qkv_a = qkv_a.view(batch_size, -1, 3 * self.num_heads, self.head_dim).transpose(1, 2)
q_a, k_a, v_a = qkv_a.chunk(3, dim=1)
q_a, k_a = self.norm_q_a(q_a), self.norm_k_a(k_a)
# Part B
qkv_b = self.b_to_qkv(hidden_states_b)
qkv_b = qkv_b.view(batch_size, -1, 3 * self.num_heads, self.head_dim).transpose(1, 2)
q_b, k_b, v_b = qkv_b.chunk(3, dim=1)
q_b, k_b = self.norm_q_b(q_b), self.norm_k_b(k_b)
q = torch.concat([q_b, q_a], dim=2)
k = torch.concat([k_b, k_a], dim=2)
v = torch.concat([v_b, v_a], dim=2)
q, k = self.apply_rope(q, k, image_rotary_emb)
hidden_states = torch.nn.functional.scaled_dot_product_attention(q, k, v, attn_mask=attn_mask)
hidden_states = hidden_states.transpose(1, 2).reshape(batch_size, -1, self.num_heads * self.head_dim)
hidden_states = hidden_states.to(q.dtype)
hidden_states_b, hidden_states_a = hidden_states[:, :hidden_states_b.shape[1]], hidden_states[:, hidden_states_b.shape[1]:]
if ipadapter_kwargs_list is not None:
hidden_states_a = interact_with_ipadapter(hidden_states_a, q_a, **ipadapter_kwargs_list)
hidden_states_a = self.a_to_out(hidden_states_a)
if self.only_out_a:
return hidden_states_a
else:
hidden_states_b = self.b_to_out(hidden_states_b)
return hidden_states_a, hidden_states_b
class FluxJointTransformerBlock(torch.nn.Module):
def __init__(self, dim, num_attention_heads):
super().__init__()
self.norm1_a = AdaLayerNorm(dim)
self.norm1_b = AdaLayerNorm(dim)
self.attn = FluxJointAttention(dim, dim, num_attention_heads, dim // num_attention_heads)
self.norm2_a = torch.nn.LayerNorm(dim, elementwise_affine=False, eps=1e-6)
self.ff_a = torch.nn.Sequential(
torch.nn.Linear(dim, dim*4),
torch.nn.GELU(approximate="tanh"),
torch.nn.Linear(dim*4, dim)
)
self.norm2_b = torch.nn.LayerNorm(dim, elementwise_affine=False, eps=1e-6)
self.ff_b = torch.nn.Sequential(
torch.nn.Linear(dim, dim*4),
torch.nn.GELU(approximate="tanh"),
torch.nn.Linear(dim*4, dim)
)
def forward(self, hidden_states_a, hidden_states_b, temb, image_rotary_emb, attn_mask=None, ipadapter_kwargs_list=None):
norm_hidden_states_a, gate_msa_a, shift_mlp_a, scale_mlp_a, gate_mlp_a = self.norm1_a(hidden_states_a, emb=temb)
norm_hidden_states_b, gate_msa_b, shift_mlp_b, scale_mlp_b, gate_mlp_b = self.norm1_b(hidden_states_b, emb=temb)
# Attention
attn_output_a, attn_output_b = self.attn(norm_hidden_states_a, norm_hidden_states_b, image_rotary_emb, attn_mask, ipadapter_kwargs_list)
# Part A
hidden_states_a = hidden_states_a + gate_msa_a * attn_output_a
norm_hidden_states_a = self.norm2_a(hidden_states_a) * (1 + scale_mlp_a) + shift_mlp_a
hidden_states_a = hidden_states_a + gate_mlp_a * self.ff_a(norm_hidden_states_a)
# Part B
hidden_states_b = hidden_states_b + gate_msa_b * attn_output_b
norm_hidden_states_b = self.norm2_b(hidden_states_b) * (1 + scale_mlp_b) + shift_mlp_b
hidden_states_b = hidden_states_b + gate_mlp_b * self.ff_b(norm_hidden_states_b)
return hidden_states_a, hidden_states_b
class FluxSingleAttention(torch.nn.Module):
def __init__(self, dim_a, dim_b, num_heads, head_dim):
super().__init__()
self.num_heads = num_heads
self.head_dim = head_dim
self.a_to_qkv = torch.nn.Linear(dim_a, dim_a * 3)
self.norm_q_a = RMSNorm(head_dim, eps=1e-6)
self.norm_k_a = RMSNorm(head_dim, eps=1e-6)
def apply_rope(self, xq, xk, freqs_cis):
xq_ = xq.float().reshape(*xq.shape[:-1], -1, 1, 2)
xk_ = xk.float().reshape(*xk.shape[:-1], -1, 1, 2)
xq_out = freqs_cis[..., 0] * xq_[..., 0] + freqs_cis[..., 1] * xq_[..., 1]
xk_out = freqs_cis[..., 0] * xk_[..., 0] + freqs_cis[..., 1] * xk_[..., 1]
return xq_out.reshape(*xq.shape).type_as(xq), xk_out.reshape(*xk.shape).type_as(xk)
def forward(self, hidden_states, image_rotary_emb):
batch_size = hidden_states.shape[0]
qkv_a = self.a_to_qkv(hidden_states)
qkv_a = qkv_a.view(batch_size, -1, 3 * self.num_heads, self.head_dim).transpose(1, 2)
q_a, k_a, v = qkv_a.chunk(3, dim=1)
q_a, k_a = self.norm_q_a(q_a), self.norm_k_a(k_a)
q, k = self.apply_rope(q_a, k_a, image_rotary_emb)
hidden_states = torch.nn.functional.scaled_dot_product_attention(q, k, v)
hidden_states = hidden_states.transpose(1, 2).reshape(batch_size, -1, self.num_heads * self.head_dim)
hidden_states = hidden_states.to(q.dtype)
return hidden_states
class AdaLayerNormSingle(torch.nn.Module):
def __init__(self, dim):
super().__init__()
self.silu = torch.nn.SiLU()
self.linear = torch.nn.Linear(dim, 3 * dim, bias=True)
self.norm = torch.nn.LayerNorm(dim, elementwise_affine=False, eps=1e-6)
def forward(self, x, emb):
emb = self.linear(self.silu(emb))
shift_msa, scale_msa, gate_msa = emb.chunk(3, dim=1)
x = self.norm(x) * (1 + scale_msa[:, None]) + shift_msa[:, None]
return x, gate_msa
class FluxSingleTransformerBlock(torch.nn.Module):
def __init__(self, dim, num_attention_heads):
super().__init__()
self.num_heads = num_attention_heads
self.head_dim = dim // num_attention_heads
self.dim = dim
self.norm = AdaLayerNormSingle(dim)
self.to_qkv_mlp = torch.nn.Linear(dim, dim * (3 + 4))
self.norm_q_a = RMSNorm(self.head_dim, eps=1e-6)
self.norm_k_a = RMSNorm(self.head_dim, eps=1e-6)
self.proj_out = torch.nn.Linear(dim * 5, dim)
def apply_rope(self, xq, xk, freqs_cis):
xq_ = xq.float().reshape(*xq.shape[:-1], -1, 1, 2)
xk_ = xk.float().reshape(*xk.shape[:-1], -1, 1, 2)
xq_out = freqs_cis[..., 0] * xq_[..., 0] + freqs_cis[..., 1] * xq_[..., 1]
xk_out = freqs_cis[..., 0] * xk_[..., 0] + freqs_cis[..., 1] * xk_[..., 1]
return xq_out.reshape(*xq.shape).type_as(xq), xk_out.reshape(*xk.shape).type_as(xk)
def process_attention(self, hidden_states, image_rotary_emb, attn_mask=None, ipadapter_kwargs_list=None):
batch_size = hidden_states.shape[0]
qkv = hidden_states.view(batch_size, -1, 3 * self.num_heads, self.head_dim).transpose(1, 2)
q, k, v = qkv.chunk(3, dim=1)
q, k = self.norm_q_a(q), self.norm_k_a(k)
q, k = self.apply_rope(q, k, image_rotary_emb)
hidden_states = torch.nn.functional.scaled_dot_product_attention(q, k, v, attn_mask=attn_mask)
hidden_states = hidden_states.transpose(1, 2).reshape(batch_size, -1, self.num_heads * self.head_dim)
hidden_states = hidden_states.to(q.dtype)
if ipadapter_kwargs_list is not None:
hidden_states = interact_with_ipadapter(hidden_states, q, **ipadapter_kwargs_list)
return hidden_states
def forward(self, hidden_states_a, hidden_states_b, temb, image_rotary_emb, attn_mask=None, ipadapter_kwargs_list=None):
residual = hidden_states_a
norm_hidden_states, gate = self.norm(hidden_states_a, emb=temb)
hidden_states_a = self.to_qkv_mlp(norm_hidden_states)
attn_output, mlp_hidden_states = hidden_states_a[:, :, :self.dim * 3], hidden_states_a[:, :, self.dim * 3:]
attn_output = self.process_attention(attn_output, image_rotary_emb, attn_mask, ipadapter_kwargs_list)
mlp_hidden_states = torch.nn.functional.gelu(mlp_hidden_states, approximate="tanh")
hidden_states_a = torch.cat([attn_output, mlp_hidden_states], dim=2)
hidden_states_a = gate.unsqueeze(1) * self.proj_out(hidden_states_a)
hidden_states_a = residual + hidden_states_a
return hidden_states_a, hidden_states_b
class AdaLayerNormContinuous(torch.nn.Module):
def __init__(self, dim):
super().__init__()
self.silu = torch.nn.SiLU()
self.linear = torch.nn.Linear(dim, dim * 2, bias=True)
self.norm = torch.nn.LayerNorm(dim, eps=1e-6, elementwise_affine=False)
def forward(self, x, conditioning):
emb = self.linear(self.silu(conditioning))
shift, scale = torch.chunk(emb, 2, dim=1)
x = self.norm(x) * (1 + scale)[:, None] + shift[:, None]
return x
class FluxDiT(torch.nn.Module):
def __init__(self, disable_guidance_embedder=False, input_dim=64, num_blocks=19):
super().__init__()
self.pos_embedder = RoPEEmbedding(3072, 10000, [16, 56, 56])
self.time_embedder = TimestepEmbeddings(256, 3072)
self.guidance_embedder = None if disable_guidance_embedder else TimestepEmbeddings(256, 3072)
self.pooled_text_embedder = torch.nn.Sequential(torch.nn.Linear(768, 3072), torch.nn.SiLU(), torch.nn.Linear(3072, 3072))
self.context_embedder = torch.nn.Linear(4096, 3072)
self.x_embedder = torch.nn.Linear(input_dim, 3072)
self.blocks = torch.nn.ModuleList([FluxJointTransformerBlock(3072, 24) for _ in range(num_blocks)])
self.single_blocks = torch.nn.ModuleList([FluxSingleTransformerBlock(3072, 24) for _ in range(38)])
self.final_norm_out = AdaLayerNormContinuous(3072)
self.final_proj_out = torch.nn.Linear(3072, 64)
self.input_dim = input_dim
def patchify(self, hidden_states):
hidden_states = rearrange(hidden_states, "B C (H P) (W Q) -> B (H W) (C P Q)", P=2, Q=2)
return hidden_states
def unpatchify(self, hidden_states, height, width):
hidden_states = rearrange(hidden_states, "B (H W) (C P Q) -> B C (H P) (W Q)", P=2, Q=2, H=height//2, W=width//2)
return hidden_states
def prepare_image_ids(self, latents):
batch_size, _, height, width = latents.shape
latent_image_ids = torch.zeros(height // 2, width // 2, 3)
latent_image_ids[..., 1] = latent_image_ids[..., 1] + torch.arange(height // 2)[:, None]
latent_image_ids[..., 2] = latent_image_ids[..., 2] + torch.arange(width // 2)[None, :]
latent_image_id_height, latent_image_id_width, latent_image_id_channels = latent_image_ids.shape
latent_image_ids = latent_image_ids[None, :].repeat(batch_size, 1, 1, 1)
latent_image_ids = latent_image_ids.reshape(
batch_size, latent_image_id_height * latent_image_id_width, latent_image_id_channels
)
latent_image_ids = latent_image_ids.to(device=latents.device, dtype=latents.dtype)
return latent_image_ids
def construct_mask(self, entity_masks, prompt_seq_len, image_seq_len):
N = len(entity_masks)
batch_size = entity_masks[0].shape[0]
total_seq_len = N * prompt_seq_len + image_seq_len
patched_masks = [self.patchify(entity_masks[i]) for i in range(N)]
attention_mask = torch.ones((batch_size, total_seq_len, total_seq_len), dtype=torch.bool).to(device=entity_masks[0].device)
image_start = N * prompt_seq_len
image_end = N * prompt_seq_len + image_seq_len
# prompt-image mask
for i in range(N):
prompt_start = i * prompt_seq_len
prompt_end = (i + 1) * prompt_seq_len
image_mask = torch.sum(patched_masks[i], dim=-1) > 0
image_mask = image_mask.unsqueeze(1).repeat(1, prompt_seq_len, 1)
# prompt update with image
attention_mask[:, prompt_start:prompt_end, image_start:image_end] = image_mask
# image update with prompt
attention_mask[:, image_start:image_end, prompt_start:prompt_end] = image_mask.transpose(1, 2)
# prompt-prompt mask
for i in range(N):
for j in range(N):
if i != j:
prompt_start_i = i * prompt_seq_len
prompt_end_i = (i + 1) * prompt_seq_len
prompt_start_j = j * prompt_seq_len
prompt_end_j = (j + 1) * prompt_seq_len
attention_mask[:, prompt_start_i:prompt_end_i, prompt_start_j:prompt_end_j] = False
attention_mask = attention_mask.float()
attention_mask[attention_mask == 0] = float('-inf')
attention_mask[attention_mask == 1] = 0
return attention_mask
def process_entity_masks(self, hidden_states, prompt_emb, entity_prompt_emb, entity_masks, text_ids, image_ids, repeat_dim):
max_masks = 0
attention_mask = None
prompt_embs = [prompt_emb]
if entity_masks is not None:
# entity_masks
batch_size, max_masks = entity_masks.shape[0], entity_masks.shape[1]
entity_masks = entity_masks.repeat(1, 1, repeat_dim, 1, 1)
entity_masks = [entity_masks[:, i, None].squeeze(1) for i in range(max_masks)]
# global mask
global_mask = torch.ones_like(entity_masks[0]).to(device=hidden_states.device, dtype=hidden_states.dtype)
entity_masks = entity_masks + [global_mask] # append global to last
# attention mask
attention_mask = self.construct_mask(entity_masks, prompt_emb.shape[1], hidden_states.shape[1])
attention_mask = attention_mask.to(device=hidden_states.device, dtype=hidden_states.dtype)
attention_mask = attention_mask.unsqueeze(1)
# embds: n_masks * b * seq * d
local_embs = [entity_prompt_emb[:, i, None].squeeze(1) for i in range(max_masks)]
prompt_embs = local_embs + prompt_embs # append global to last
prompt_embs = [self.context_embedder(prompt_emb) for prompt_emb in prompt_embs]
prompt_emb = torch.cat(prompt_embs, dim=1)
# positional embedding
text_ids = torch.cat([text_ids] * (max_masks + 1), dim=1)
image_rotary_emb = self.pos_embedder(torch.cat((text_ids, image_ids), dim=1))
return prompt_emb, image_rotary_emb, attention_mask
def forward(
self,
hidden_states,
timestep, prompt_emb, pooled_prompt_emb, guidance, text_ids, image_ids=None,
tiled=False, tile_size=128, tile_stride=64, entity_prompt_emb=None, entity_masks=None,
use_gradient_checkpointing=False,
**kwargs
):
# (Deprecated) The real forward is in `pipelines.flux_image`.
return None