ComfyUI/comfy/ldm/wan/vae.py

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2025-02-25 22:20:35 +00:00
# original version: https://github.com/Wan-Video/Wan2.1/blob/main/wan/modules/vae.py
# Copyright 2024-2025 The Alibaba Wan Team Authors. All rights reserved.
import torch
import torch.nn as nn
import torch.nn.functional as F
from einops import rearrange
from comfy.ldm.modules.diffusionmodules.model import vae_attention
import comfy.ops
ops = comfy.ops.disable_weight_init
CACHE_T = 2
class CausalConv3d(ops.Conv3d):
"""
Causal 3d convolusion.
"""
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
self._padding = (self.padding[2], self.padding[2], self.padding[1],
self.padding[1], 2 * self.padding[0], 0)
self.padding = (0, 0, 0)
def forward(self, x, cache_x=None):
padding = list(self._padding)
if cache_x is not None and self._padding[4] > 0:
cache_x = cache_x.to(x.device)
x = torch.cat([cache_x, x], dim=2)
padding[4] -= cache_x.shape[2]
x = F.pad(x, padding)
return super().forward(x)
class RMS_norm(nn.Module):
def __init__(self, dim, channel_first=True, images=True, bias=False):
super().__init__()
broadcastable_dims = (1, 1, 1) if not images else (1, 1)
shape = (dim, *broadcastable_dims) if channel_first else (dim,)
self.channel_first = channel_first
self.scale = dim**0.5
self.gamma = nn.Parameter(torch.ones(shape))
self.bias = nn.Parameter(torch.zeros(shape)) if bias else None
def forward(self, x):
return F.normalize(
x, dim=(1 if self.channel_first else -1)) * self.scale * self.gamma.to(x) + (self.bias.to(x) if self.bias is not None else 0)
class Upsample(nn.Upsample):
def forward(self, x):
"""
Fix bfloat16 support for nearest neighbor interpolation.
"""
return super().forward(x.float()).type_as(x)
class Resample(nn.Module):
def __init__(self, dim, mode):
assert mode in ('none', 'upsample2d', 'upsample3d', 'downsample2d',
'downsample3d')
super().__init__()
self.dim = dim
self.mode = mode
# layers
if mode == 'upsample2d':
self.resample = nn.Sequential(
Upsample(scale_factor=(2., 2.), mode='nearest-exact'),
ops.Conv2d(dim, dim // 2, 3, padding=1))
elif mode == 'upsample3d':
self.resample = nn.Sequential(
Upsample(scale_factor=(2., 2.), mode='nearest-exact'),
ops.Conv2d(dim, dim // 2, 3, padding=1))
self.time_conv = CausalConv3d(
dim, dim * 2, (3, 1, 1), padding=(1, 0, 0))
elif mode == 'downsample2d':
self.resample = nn.Sequential(
nn.ZeroPad2d((0, 1, 0, 1)),
ops.Conv2d(dim, dim, 3, stride=(2, 2)))
elif mode == 'downsample3d':
self.resample = nn.Sequential(
nn.ZeroPad2d((0, 1, 0, 1)),
ops.Conv2d(dim, dim, 3, stride=(2, 2)))
self.time_conv = CausalConv3d(
dim, dim, (3, 1, 1), stride=(2, 1, 1), padding=(0, 0, 0))
else:
self.resample = nn.Identity()
def forward(self, x, feat_cache=None, feat_idx=[0]):
b, c, t, h, w = x.size()
if self.mode == 'upsample3d':
if feat_cache is not None:
idx = feat_idx[0]
if feat_cache[idx] is None:
feat_cache[idx] = 'Rep'
feat_idx[0] += 1
else:
cache_x = x[:, :, -CACHE_T:, :, :].clone()
if cache_x.shape[2] < 2 and feat_cache[
idx] is not None and feat_cache[idx] != 'Rep':
# cache last frame of last two chunk
cache_x = torch.cat([
feat_cache[idx][:, :, -1, :, :].unsqueeze(2).to(
cache_x.device), cache_x
],
dim=2)
if cache_x.shape[2] < 2 and feat_cache[
idx] is not None and feat_cache[idx] == 'Rep':
cache_x = torch.cat([
torch.zeros_like(cache_x).to(cache_x.device),
cache_x
],
dim=2)
if feat_cache[idx] == 'Rep':
x = self.time_conv(x)
else:
x = self.time_conv(x, feat_cache[idx])
feat_cache[idx] = cache_x
feat_idx[0] += 1
x = x.reshape(b, 2, c, t, h, w)
x = torch.stack((x[:, 0, :, :, :, :], x[:, 1, :, :, :, :]),
3)
x = x.reshape(b, c, t * 2, h, w)
t = x.shape[2]
x = rearrange(x, 'b c t h w -> (b t) c h w')
x = self.resample(x)
x = rearrange(x, '(b t) c h w -> b c t h w', t=t)
if self.mode == 'downsample3d':
if feat_cache is not None:
idx = feat_idx[0]
if feat_cache[idx] is None:
feat_cache[idx] = x.clone()
feat_idx[0] += 1
else:
cache_x = x[:, :, -1:, :, :].clone()
# if cache_x.shape[2] < 2 and feat_cache[idx] is not None and feat_cache[idx]!='Rep':
# # cache last frame of last two chunk
# cache_x = torch.cat([feat_cache[idx][:, :, -1, :, :].unsqueeze(2).to(cache_x.device), cache_x], dim=2)
x = self.time_conv(
torch.cat([feat_cache[idx][:, :, -1:, :, :], x], 2))
feat_cache[idx] = cache_x
feat_idx[0] += 1
return x
def init_weight(self, conv):
conv_weight = conv.weight
nn.init.zeros_(conv_weight)
c1, c2, t, h, w = conv_weight.size()
one_matrix = torch.eye(c1, c2)
init_matrix = one_matrix
nn.init.zeros_(conv_weight)
#conv_weight.data[:,:,-1,1,1] = init_matrix * 0.5
conv_weight.data[:, :, 1, 0, 0] = init_matrix #* 0.5
conv.weight.data.copy_(conv_weight)
nn.init.zeros_(conv.bias.data)
def init_weight2(self, conv):
conv_weight = conv.weight.data
nn.init.zeros_(conv_weight)
c1, c2, t, h, w = conv_weight.size()
init_matrix = torch.eye(c1 // 2, c2)
#init_matrix = repeat(init_matrix, 'o ... -> (o 2) ...').permute(1,0,2).contiguous().reshape(c1,c2)
conv_weight[:c1 // 2, :, -1, 0, 0] = init_matrix
conv_weight[c1 // 2:, :, -1, 0, 0] = init_matrix
conv.weight.data.copy_(conv_weight)
nn.init.zeros_(conv.bias.data)
class ResidualBlock(nn.Module):
def __init__(self, in_dim, out_dim, dropout=0.0):
super().__init__()
self.in_dim = in_dim
self.out_dim = out_dim
# layers
self.residual = nn.Sequential(
RMS_norm(in_dim, images=False), nn.SiLU(),
CausalConv3d(in_dim, out_dim, 3, padding=1),
RMS_norm(out_dim, images=False), nn.SiLU(), nn.Dropout(dropout),
CausalConv3d(out_dim, out_dim, 3, padding=1))
self.shortcut = CausalConv3d(in_dim, out_dim, 1) \
if in_dim != out_dim else nn.Identity()
def forward(self, x, feat_cache=None, feat_idx=[0]):
h = self.shortcut(x)
for layer in self.residual:
if isinstance(layer, CausalConv3d) and feat_cache is not None:
idx = feat_idx[0]
cache_x = x[:, :, -CACHE_T:, :, :].clone()
if cache_x.shape[2] < 2 and feat_cache[idx] is not None:
# cache last frame of last two chunk
cache_x = torch.cat([
feat_cache[idx][:, :, -1, :, :].unsqueeze(2).to(
cache_x.device), cache_x
],
dim=2)
x = layer(x, feat_cache[idx])
feat_cache[idx] = cache_x
feat_idx[0] += 1
else:
x = layer(x)
return x + h
class AttentionBlock(nn.Module):
"""
Causal self-attention with a single head.
"""
def __init__(self, dim):
super().__init__()
self.dim = dim
# layers
self.norm = RMS_norm(dim)
self.to_qkv = ops.Conv2d(dim, dim * 3, 1)
self.proj = ops.Conv2d(dim, dim, 1)
self.optimized_attention = vae_attention()
def forward(self, x):
identity = x
b, c, t, h, w = x.size()
x = rearrange(x, 'b c t h w -> (b t) c h w')
x = self.norm(x)
# compute query, key, value
q, k, v = self.to_qkv(x).chunk(3, dim=1)
x = self.optimized_attention(q, k, v)
# output
x = self.proj(x)
x = rearrange(x, '(b t) c h w-> b c t h w', t=t)
return x + identity
class Encoder3d(nn.Module):
def __init__(self,
dim=128,
z_dim=4,
dim_mult=[1, 2, 4, 4],
num_res_blocks=2,
attn_scales=[],
temperal_downsample=[True, True, False],
dropout=0.0):
super().__init__()
self.dim = dim
self.z_dim = z_dim
self.dim_mult = dim_mult
self.num_res_blocks = num_res_blocks
self.attn_scales = attn_scales
self.temperal_downsample = temperal_downsample
# dimensions
dims = [dim * u for u in [1] + dim_mult]
scale = 1.0
# init block
self.conv1 = CausalConv3d(3, dims[0], 3, padding=1)
# downsample blocks
downsamples = []
for i, (in_dim, out_dim) in enumerate(zip(dims[:-1], dims[1:])):
# residual (+attention) blocks
for _ in range(num_res_blocks):
downsamples.append(ResidualBlock(in_dim, out_dim, dropout))
if scale in attn_scales:
downsamples.append(AttentionBlock(out_dim))
in_dim = out_dim
# downsample block
if i != len(dim_mult) - 1:
mode = 'downsample3d' if temperal_downsample[
i] else 'downsample2d'
downsamples.append(Resample(out_dim, mode=mode))
scale /= 2.0
self.downsamples = nn.Sequential(*downsamples)
# middle blocks
self.middle = nn.Sequential(
ResidualBlock(out_dim, out_dim, dropout), AttentionBlock(out_dim),
ResidualBlock(out_dim, out_dim, dropout))
# output blocks
self.head = nn.Sequential(
RMS_norm(out_dim, images=False), nn.SiLU(),
CausalConv3d(out_dim, z_dim, 3, padding=1))
def forward(self, x, feat_cache=None, feat_idx=[0]):
if feat_cache is not None:
idx = feat_idx[0]
cache_x = x[:, :, -CACHE_T:, :, :].clone()
if cache_x.shape[2] < 2 and feat_cache[idx] is not None:
# cache last frame of last two chunk
cache_x = torch.cat([
feat_cache[idx][:, :, -1, :, :].unsqueeze(2).to(
cache_x.device), cache_x
],
dim=2)
x = self.conv1(x, feat_cache[idx])
feat_cache[idx] = cache_x
feat_idx[0] += 1
else:
x = self.conv1(x)
## downsamples
for layer in self.downsamples:
if feat_cache is not None:
x = layer(x, feat_cache, feat_idx)
else:
x = layer(x)
## middle
for layer in self.middle:
if isinstance(layer, ResidualBlock) and feat_cache is not None:
x = layer(x, feat_cache, feat_idx)
else:
x = layer(x)
## head
for layer in self.head:
if isinstance(layer, CausalConv3d) and feat_cache is not None:
idx = feat_idx[0]
cache_x = x[:, :, -CACHE_T:, :, :].clone()
if cache_x.shape[2] < 2 and feat_cache[idx] is not None:
# cache last frame of last two chunk
cache_x = torch.cat([
feat_cache[idx][:, :, -1, :, :].unsqueeze(2).to(
cache_x.device), cache_x
],
dim=2)
x = layer(x, feat_cache[idx])
feat_cache[idx] = cache_x
feat_idx[0] += 1
else:
x = layer(x)
return x
class Decoder3d(nn.Module):
def __init__(self,
dim=128,
z_dim=4,
dim_mult=[1, 2, 4, 4],
num_res_blocks=2,
attn_scales=[],
temperal_upsample=[False, True, True],
dropout=0.0):
super().__init__()
self.dim = dim
self.z_dim = z_dim
self.dim_mult = dim_mult
self.num_res_blocks = num_res_blocks
self.attn_scales = attn_scales
self.temperal_upsample = temperal_upsample
# dimensions
dims = [dim * u for u in [dim_mult[-1]] + dim_mult[::-1]]
scale = 1.0 / 2**(len(dim_mult) - 2)
# init block
self.conv1 = CausalConv3d(z_dim, dims[0], 3, padding=1)
# middle blocks
self.middle = nn.Sequential(
ResidualBlock(dims[0], dims[0], dropout), AttentionBlock(dims[0]),
ResidualBlock(dims[0], dims[0], dropout))
# upsample blocks
upsamples = []
for i, (in_dim, out_dim) in enumerate(zip(dims[:-1], dims[1:])):
# residual (+attention) blocks
if i == 1 or i == 2 or i == 3:
in_dim = in_dim // 2
for _ in range(num_res_blocks + 1):
upsamples.append(ResidualBlock(in_dim, out_dim, dropout))
if scale in attn_scales:
upsamples.append(AttentionBlock(out_dim))
in_dim = out_dim
# upsample block
if i != len(dim_mult) - 1:
mode = 'upsample3d' if temperal_upsample[i] else 'upsample2d'
upsamples.append(Resample(out_dim, mode=mode))
scale *= 2.0
self.upsamples = nn.Sequential(*upsamples)
# output blocks
self.head = nn.Sequential(
RMS_norm(out_dim, images=False), nn.SiLU(),
CausalConv3d(out_dim, 3, 3, padding=1))
def forward(self, x, feat_cache=None, feat_idx=[0]):
## conv1
if feat_cache is not None:
idx = feat_idx[0]
cache_x = x[:, :, -CACHE_T:, :, :].clone()
if cache_x.shape[2] < 2 and feat_cache[idx] is not None:
# cache last frame of last two chunk
cache_x = torch.cat([
feat_cache[idx][:, :, -1, :, :].unsqueeze(2).to(
cache_x.device), cache_x
],
dim=2)
x = self.conv1(x, feat_cache[idx])
feat_cache[idx] = cache_x
feat_idx[0] += 1
else:
x = self.conv1(x)
## middle
for layer in self.middle:
if isinstance(layer, ResidualBlock) and feat_cache is not None:
x = layer(x, feat_cache, feat_idx)
else:
x = layer(x)
## upsamples
for layer in self.upsamples:
if feat_cache is not None:
x = layer(x, feat_cache, feat_idx)
else:
x = layer(x)
## head
for layer in self.head:
if isinstance(layer, CausalConv3d) and feat_cache is not None:
idx = feat_idx[0]
cache_x = x[:, :, -CACHE_T:, :, :].clone()
if cache_x.shape[2] < 2 and feat_cache[idx] is not None:
# cache last frame of last two chunk
cache_x = torch.cat([
feat_cache[idx][:, :, -1, :, :].unsqueeze(2).to(
cache_x.device), cache_x
],
dim=2)
x = layer(x, feat_cache[idx])
feat_cache[idx] = cache_x
feat_idx[0] += 1
else:
x = layer(x)
return x
def count_conv3d(model):
count = 0
for m in model.modules():
if isinstance(m, CausalConv3d):
count += 1
return count
class WanVAE(nn.Module):
def __init__(self,
dim=128,
z_dim=4,
dim_mult=[1, 2, 4, 4],
num_res_blocks=2,
attn_scales=[],
temperal_downsample=[True, True, False],
dropout=0.0):
super().__init__()
self.dim = dim
self.z_dim = z_dim
self.dim_mult = dim_mult
self.num_res_blocks = num_res_blocks
self.attn_scales = attn_scales
self.temperal_downsample = temperal_downsample
self.temperal_upsample = temperal_downsample[::-1]
# modules
self.encoder = Encoder3d(dim, z_dim * 2, dim_mult, num_res_blocks,
attn_scales, self.temperal_downsample, dropout)
self.conv1 = CausalConv3d(z_dim * 2, z_dim * 2, 1)
self.conv2 = CausalConv3d(z_dim, z_dim, 1)
self.decoder = Decoder3d(dim, z_dim, dim_mult, num_res_blocks,
attn_scales, self.temperal_upsample, dropout)
def forward(self, x):
mu, log_var = self.encode(x)
z = self.reparameterize(mu, log_var)
x_recon = self.decode(z)
return x_recon, mu, log_var
def encode(self, x):
self.clear_cache()
## cache
t = x.shape[2]
iter_ = 1 + (t - 1) // 4
## 对encode输入的x按时间拆分为1、4、4、4....
for i in range(iter_):
self._enc_conv_idx = [0]
if i == 0:
out = self.encoder(
x[:, :, :1, :, :],
feat_cache=self._enc_feat_map,
feat_idx=self._enc_conv_idx)
else:
out_ = self.encoder(
x[:, :, 1 + 4 * (i - 1):1 + 4 * i, :, :],
feat_cache=self._enc_feat_map,
feat_idx=self._enc_conv_idx)
out = torch.cat([out, out_], 2)
mu, log_var = self.conv1(out).chunk(2, dim=1)
self.clear_cache()
return mu
def decode(self, z):
self.clear_cache()
# z: [b,c,t,h,w]
iter_ = z.shape[2]
x = self.conv2(z)
for i in range(iter_):
self._conv_idx = [0]
if i == 0:
out = self.decoder(
x[:, :, i:i + 1, :, :],
feat_cache=self._feat_map,
feat_idx=self._conv_idx)
else:
out_ = self.decoder(
x[:, :, i:i + 1, :, :],
feat_cache=self._feat_map,
feat_idx=self._conv_idx)
out = torch.cat([out, out_], 2)
self.clear_cache()
return out
def reparameterize(self, mu, log_var):
std = torch.exp(0.5 * log_var)
eps = torch.randn_like(std)
return eps * std + mu
def sample(self, imgs, deterministic=False):
mu, log_var = self.encode(imgs)
if deterministic:
return mu
std = torch.exp(0.5 * log_var.clamp(-30.0, 20.0))
return mu + std * torch.randn_like(std)
def clear_cache(self):
self._conv_num = count_conv3d(self.decoder)
self._conv_idx = [0]
self._feat_map = [None] * self._conv_num
#cache encode
self._enc_conv_num = count_conv3d(self.encoder)
self._enc_conv_idx = [0]
self._enc_feat_map = [None] * self._enc_conv_num