ComfyUI/comfy/ldm/cogvideo/vae.py
2026-04-10 20:28:05 +02:00

571 lines
24 KiB
Python

# CogVideoX VAE - ported to ComfyUI native ops
# Architecture reference: diffusers AutoencoderKLCogVideoX
# Style reference: comfy/ldm/wan/vae.py
import numpy as np
import torch
import torch.nn as nn
import torch.nn.functional as F
import comfy.ops
ops = comfy.ops.disable_weight_init
class CausalConv3d(nn.Module):
"""Causal 3D convolution with temporal padding.
Uses comfy.ops.Conv3d with autopad='causal_zero' fast path: when input has
a single temporal frame and no cache, the 3D conv weight is sliced to act
as a 2D conv, avoiding computation on zero-padded temporal dimensions.
"""
def __init__(self, in_channels, out_channels, kernel_size, stride=1, dilation=1, pad_mode="constant"):
super().__init__()
if isinstance(kernel_size, int):
kernel_size = (kernel_size,) * 3
time_kernel, height_kernel, width_kernel = kernel_size
self.time_kernel_size = time_kernel
self.pad_mode = pad_mode
height_pad = (height_kernel - 1) // 2
width_pad = (width_kernel - 1) // 2
self.time_causal_padding = (width_pad, width_pad, height_pad, height_pad, time_kernel - 1, 0)
stride = stride if isinstance(stride, tuple) else (stride, 1, 1)
dilation = (dilation, 1, 1)
self.conv = ops.Conv3d(
in_channels, out_channels, kernel_size,
stride=stride, dilation=dilation,
padding=(0, height_pad, width_pad),
)
def forward(self, x, conv_cache=None):
if self.pad_mode == "replicate":
x = F.pad(x, self.time_causal_padding, mode="replicate")
conv_cache = None
else:
kernel_t = self.time_kernel_size
if kernel_t > 1:
if conv_cache is None and x.shape[2] == 1:
# Fast path: single frame, no cache. All temporal padding
# frames are copies of the input (replicate-style), so the
# 3D conv reduces to a 2D conv with summed temporal kernel.
w = comfy.ops.cast_to_input(self.conv.weight, x)
b = comfy.ops.cast_to_input(self.conv.bias, x) if self.conv.bias is not None else None
w2d = w.sum(dim=2, keepdim=True)
out = F.conv3d(x, w2d, b,
self.conv.stride, self.conv.padding,
self.conv.dilation, self.conv.groups)
return out, None
cached = [conv_cache] if conv_cache is not None else [x[:, :, :1]] * (kernel_t - 1)
x = torch.cat(cached + [x], dim=2)
conv_cache = x[:, :, -self.time_kernel_size + 1:].clone() if self.time_kernel_size > 1 else None
out = self.conv(x)
return out, conv_cache
def _interpolate_zq(zq, target_size):
"""Interpolate latent z to target (T, H, W), matching CogVideoX's first-frame-special handling."""
t = target_size[0]
if t > 1 and t % 2 == 1:
z_first = F.interpolate(zq[:, :, :1], size=(1, target_size[1], target_size[2]))
z_rest = F.interpolate(zq[:, :, 1:], size=(t - 1, target_size[1], target_size[2]))
return torch.cat([z_first, z_rest], dim=2)
return F.interpolate(zq, size=target_size)
class SpatialNorm3D(nn.Module):
"""Spatially conditioned normalization."""
def __init__(self, f_channels, zq_channels, groups=32):
super().__init__()
self.norm_layer = nn.GroupNorm(num_channels=f_channels, num_groups=groups, eps=1e-6, affine=True)
self.conv_y = CausalConv3d(zq_channels, f_channels, kernel_size=1, stride=1)
self.conv_b = CausalConv3d(zq_channels, f_channels, kernel_size=1, stride=1)
def forward(self, f, zq, conv_cache=None):
new_cache = {}
conv_cache = conv_cache or {}
if zq.shape[-3:] != f.shape[-3:]:
zq = _interpolate_zq(zq, f.shape[-3:])
conv_y, new_cache["conv_y"] = self.conv_y(zq, conv_cache=conv_cache.get("conv_y"))
conv_b, new_cache["conv_b"] = self.conv_b(zq, conv_cache=conv_cache.get("conv_b"))
return self.norm_layer(f) * conv_y + conv_b, new_cache
class ResnetBlock3D(nn.Module):
"""3D ResNet block with optional spatial norm."""
def __init__(self, in_channels, out_channels=None, temb_channels=512, groups=32,
eps=1e-6, act_fn="silu", spatial_norm_dim=None, pad_mode="first"):
super().__init__()
out_channels = out_channels or in_channels
self.in_channels = in_channels
self.out_channels = out_channels
self.spatial_norm_dim = spatial_norm_dim
if act_fn == "silu":
self.nonlinearity = nn.SiLU()
elif act_fn == "swish":
self.nonlinearity = nn.SiLU()
else:
self.nonlinearity = nn.SiLU()
if spatial_norm_dim is None:
self.norm1 = nn.GroupNorm(num_channels=in_channels, num_groups=groups, eps=eps)
self.norm2 = nn.GroupNorm(num_channels=out_channels, num_groups=groups, eps=eps)
else:
self.norm1 = SpatialNorm3D(in_channels, spatial_norm_dim, groups=groups)
self.norm2 = SpatialNorm3D(out_channels, spatial_norm_dim, groups=groups)
self.conv1 = CausalConv3d(in_channels, out_channels, kernel_size=3, pad_mode=pad_mode)
if temb_channels > 0:
self.temb_proj = nn.Linear(temb_channels, out_channels)
self.conv2 = CausalConv3d(out_channels, out_channels, kernel_size=3, pad_mode=pad_mode)
if in_channels != out_channels:
self.conv_shortcut = ops.Conv3d(in_channels, out_channels, kernel_size=1, stride=1, padding=0)
else:
self.conv_shortcut = None
def forward(self, x, temb=None, zq=None, conv_cache=None):
new_cache = {}
conv_cache = conv_cache or {}
residual = x
if zq is not None:
x, new_cache["norm1"] = self.norm1(x, zq, conv_cache=conv_cache.get("norm1"))
else:
x = self.norm1(x)
x = self.nonlinearity(x)
x, new_cache["conv1"] = self.conv1(x, conv_cache=conv_cache.get("conv1"))
if temb is not None and hasattr(self, "temb_proj"):
x = x + self.temb_proj(self.nonlinearity(temb))[:, :, None, None, None]
if zq is not None:
x, new_cache["norm2"] = self.norm2(x, zq, conv_cache=conv_cache.get("norm2"))
else:
x = self.norm2(x)
x = self.nonlinearity(x)
x, new_cache["conv2"] = self.conv2(x, conv_cache=conv_cache.get("conv2"))
if self.conv_shortcut is not None:
residual = self.conv_shortcut(residual)
return x + residual, new_cache
class Downsample3D(nn.Module):
"""3D downsampling with optional temporal compression."""
def __init__(self, in_channels, out_channels, kernel_size=3, stride=2, padding=0, compress_time=False):
super().__init__()
self.conv = nn.Conv2d(in_channels, out_channels, kernel_size=kernel_size, stride=stride, padding=padding)
self.compress_time = compress_time
def forward(self, x):
if self.compress_time:
b, c, t, h, w = x.shape
x = x.permute(0, 3, 4, 1, 2).reshape(b * h * w, c, t)
if t % 2 == 1:
x_first, x_rest = x[..., 0], x[..., 1:]
if x_rest.shape[-1] > 0:
x_rest = F.avg_pool1d(x_rest, kernel_size=2, stride=2)
x = torch.cat([x_first[..., None], x_rest], dim=-1)
x = x.reshape(b, h, w, c, x.shape[-1]).permute(0, 3, 4, 1, 2)
else:
x = F.avg_pool1d(x, kernel_size=2, stride=2)
x = x.reshape(b, h, w, c, x.shape[-1]).permute(0, 3, 4, 1, 2)
pad = (0, 1, 0, 1)
x = F.pad(x, pad, mode="constant", value=0)
b, c, t, h, w = x.shape
x = x.permute(0, 2, 1, 3, 4).reshape(b * t, c, h, w)
x = self.conv(x)
x = x.reshape(b, t, x.shape[1], x.shape[2], x.shape[3]).permute(0, 2, 1, 3, 4)
return x
class Upsample3D(nn.Module):
"""3D upsampling with optional temporal decompression."""
def __init__(self, in_channels, out_channels, kernel_size=3, stride=1, padding=1, compress_time=False):
super().__init__()
self.conv = nn.Conv2d(in_channels, out_channels, kernel_size=kernel_size, stride=stride, padding=padding)
self.compress_time = compress_time
def forward(self, x):
if self.compress_time:
if x.shape[2] > 1 and x.shape[2] % 2 == 1:
x_first, x_rest = x[:, :, 0], x[:, :, 1:]
x_first = F.interpolate(x_first, scale_factor=2.0)
x_rest = F.interpolate(x_rest, scale_factor=2.0)
x = torch.cat([x_first[:, :, None, :, :], x_rest], dim=2)
elif x.shape[2] > 1:
x = F.interpolate(x, scale_factor=2.0)
else:
x = x.squeeze(2)
x = F.interpolate(x, scale_factor=2.0)
x = x[:, :, None, :, :]
else:
b, c, t, h, w = x.shape
x = x.permute(0, 2, 1, 3, 4).reshape(b * t, c, h, w)
x = F.interpolate(x, scale_factor=2.0)
x = x.reshape(b, t, c, *x.shape[2:]).permute(0, 2, 1, 3, 4)
b, c, t, h, w = x.shape
x = x.permute(0, 2, 1, 3, 4).reshape(b * t, c, h, w)
x = self.conv(x)
x = x.reshape(b, t, *x.shape[1:]).permute(0, 2, 1, 3, 4)
return x
class DownBlock3D(nn.Module):
def __init__(self, in_channels, out_channels, temb_channels=0, num_layers=1,
eps=1e-6, act_fn="silu", groups=32, add_downsample=True,
compress_time=False, pad_mode="first"):
super().__init__()
self.resnets = nn.ModuleList([
ResnetBlock3D(
in_channels=in_channels if i == 0 else out_channels,
out_channels=out_channels,
temb_channels=temb_channels,
groups=groups, eps=eps, act_fn=act_fn, pad_mode=pad_mode,
)
for i in range(num_layers)
])
self.downsamplers = nn.ModuleList([Downsample3D(out_channels, out_channels, compress_time=compress_time)]) if add_downsample else None
def forward(self, x, temb=None, zq=None, conv_cache=None):
new_cache = {}
conv_cache = conv_cache or {}
for i, resnet in enumerate(self.resnets):
x, new_cache[f"resnet_{i}"] = resnet(x, temb, zq, conv_cache=conv_cache.get(f"resnet_{i}"))
if self.downsamplers is not None:
for ds in self.downsamplers:
x = ds(x)
return x, new_cache
class MidBlock3D(nn.Module):
def __init__(self, in_channels, temb_channels=0, num_layers=1,
eps=1e-6, act_fn="silu", groups=32, spatial_norm_dim=None, pad_mode="first"):
super().__init__()
self.resnets = nn.ModuleList([
ResnetBlock3D(
in_channels=in_channels, out_channels=in_channels,
temb_channels=temb_channels, groups=groups, eps=eps,
act_fn=act_fn, spatial_norm_dim=spatial_norm_dim, pad_mode=pad_mode,
)
for _ in range(num_layers)
])
def forward(self, x, temb=None, zq=None, conv_cache=None):
new_cache = {}
conv_cache = conv_cache or {}
for i, resnet in enumerate(self.resnets):
x, new_cache[f"resnet_{i}"] = resnet(x, temb, zq, conv_cache=conv_cache.get(f"resnet_{i}"))
return x, new_cache
class UpBlock3D(nn.Module):
def __init__(self, in_channels, out_channels, temb_channels=0, num_layers=1,
eps=1e-6, act_fn="silu", groups=32, spatial_norm_dim=16,
add_upsample=True, compress_time=False, pad_mode="first"):
super().__init__()
self.resnets = nn.ModuleList([
ResnetBlock3D(
in_channels=in_channels if i == 0 else out_channels,
out_channels=out_channels,
temb_channels=temb_channels, groups=groups, eps=eps,
act_fn=act_fn, spatial_norm_dim=spatial_norm_dim, pad_mode=pad_mode,
)
for i in range(num_layers)
])
self.upsamplers = nn.ModuleList([Upsample3D(out_channels, out_channels, compress_time=compress_time)]) if add_upsample else None
def forward(self, x, temb=None, zq=None, conv_cache=None):
new_cache = {}
conv_cache = conv_cache or {}
for i, resnet in enumerate(self.resnets):
x, new_cache[f"resnet_{i}"] = resnet(x, temb, zq, conv_cache=conv_cache.get(f"resnet_{i}"))
if self.upsamplers is not None:
for us in self.upsamplers:
x = us(x)
return x, new_cache
class Encoder3D(nn.Module):
def __init__(self, in_channels=3, out_channels=16,
block_out_channels=(128, 256, 256, 512),
layers_per_block=3, act_fn="silu",
eps=1e-6, groups=32, pad_mode="first",
temporal_compression_ratio=4):
super().__init__()
temporal_compress_level = int(np.log2(temporal_compression_ratio))
self.conv_in = CausalConv3d(in_channels, block_out_channels[0], kernel_size=3, pad_mode=pad_mode)
self.down_blocks = nn.ModuleList()
output_channel = block_out_channels[0]
for i in range(len(block_out_channels)):
input_channel = output_channel
output_channel = block_out_channels[i]
is_final = i == len(block_out_channels) - 1
compress_time = i < temporal_compress_level
self.down_blocks.append(DownBlock3D(
in_channels=input_channel, out_channels=output_channel,
temb_channels=0, num_layers=layers_per_block,
eps=eps, act_fn=act_fn, groups=groups,
add_downsample=not is_final, compress_time=compress_time,
))
self.mid_block = MidBlock3D(
in_channels=block_out_channels[-1], temb_channels=0,
num_layers=2, eps=eps, act_fn=act_fn, groups=groups, pad_mode=pad_mode,
)
self.norm_out = nn.GroupNorm(groups, block_out_channels[-1], eps=1e-6)
self.conv_act = nn.SiLU()
self.conv_out = CausalConv3d(block_out_channels[-1], 2 * out_channels, kernel_size=3, pad_mode=pad_mode)
def forward(self, x, conv_cache=None):
new_cache = {}
conv_cache = conv_cache or {}
x, new_cache["conv_in"] = self.conv_in(x, conv_cache=conv_cache.get("conv_in"))
for i, block in enumerate(self.down_blocks):
key = f"down_block_{i}"
x, new_cache[key] = block(x, None, None, conv_cache.get(key))
x, new_cache["mid_block"] = self.mid_block(x, None, None, conv_cache=conv_cache.get("mid_block"))
x = self.norm_out(x)
x = self.conv_act(x)
x, new_cache["conv_out"] = self.conv_out(x, conv_cache=conv_cache.get("conv_out"))
return x, new_cache
class Decoder3D(nn.Module):
def __init__(self, in_channels=16, out_channels=3,
block_out_channels=(128, 256, 256, 512),
layers_per_block=3, act_fn="silu",
eps=1e-6, groups=32, pad_mode="first",
temporal_compression_ratio=4):
super().__init__()
reversed_channels = list(reversed(block_out_channels))
temporal_compress_level = int(np.log2(temporal_compression_ratio))
self.conv_in = CausalConv3d(in_channels, reversed_channels[0], kernel_size=3, pad_mode=pad_mode)
self.mid_block = MidBlock3D(
in_channels=reversed_channels[0], temb_channels=0,
num_layers=2, eps=eps, act_fn=act_fn, groups=groups,
spatial_norm_dim=in_channels, pad_mode=pad_mode,
)
self.up_blocks = nn.ModuleList()
output_channel = reversed_channels[0]
for i in range(len(block_out_channels)):
prev_channel = output_channel
output_channel = reversed_channels[i]
is_final = i == len(block_out_channels) - 1
compress_time = i < temporal_compress_level
self.up_blocks.append(UpBlock3D(
in_channels=prev_channel, out_channels=output_channel,
temb_channels=0, num_layers=layers_per_block + 1,
eps=eps, act_fn=act_fn, groups=groups,
spatial_norm_dim=in_channels,
add_upsample=not is_final, compress_time=compress_time,
))
self.norm_out = SpatialNorm3D(reversed_channels[-1], in_channels, groups=groups)
self.conv_act = nn.SiLU()
self.conv_out = CausalConv3d(reversed_channels[-1], out_channels, kernel_size=3, pad_mode=pad_mode)
def forward(self, sample, conv_cache=None):
new_cache = {}
conv_cache = conv_cache or {}
x, new_cache["conv_in"] = self.conv_in(sample, conv_cache=conv_cache.get("conv_in"))
x, new_cache["mid_block"] = self.mid_block(x, None, sample, conv_cache=conv_cache.get("mid_block"))
for i, block in enumerate(self.up_blocks):
key = f"up_block_{i}"
x, new_cache[key] = block(x, None, sample, conv_cache=conv_cache.get(key))
x, new_cache["norm_out"] = self.norm_out(x, sample, conv_cache=conv_cache.get("norm_out"))
x = self.conv_act(x)
x, new_cache["conv_out"] = self.conv_out(x, conv_cache=conv_cache.get("conv_out"))
return x, new_cache
class AutoencoderKLCogVideoX(nn.Module):
"""CogVideoX VAE. Spatial tiling/slicing handled by ComfyUI's VAE wrapper.
Uses rolling temporal decode: conv_in + mid_block + temporal up_blocks run
on the full (low-res) tensor, then the expensive spatial-only up_blocks +
norm_out + conv_out are processed in small temporal chunks with conv_cache
carrying causal state between chunks. This keeps peak VRAM proportional to
chunk_size rather than total frame count.
"""
def __init__(self,
in_channels=3, out_channels=3,
block_out_channels=(128, 256, 256, 512),
latent_channels=16, layers_per_block=3,
act_fn="silu", eps=1e-6, groups=32,
temporal_compression_ratio=4,
):
super().__init__()
self.latent_channels = latent_channels
self.temporal_compression_ratio = temporal_compression_ratio
self.encoder = Encoder3D(
in_channels=in_channels, out_channels=latent_channels,
block_out_channels=block_out_channels, layers_per_block=layers_per_block,
act_fn=act_fn, eps=eps, groups=groups,
temporal_compression_ratio=temporal_compression_ratio,
)
self.decoder = Decoder3D(
in_channels=latent_channels, out_channels=out_channels,
block_out_channels=block_out_channels, layers_per_block=layers_per_block,
act_fn=act_fn, eps=eps, groups=groups,
temporal_compression_ratio=temporal_compression_ratio,
)
self.num_latent_frames_batch_size = 2
self.num_sample_frames_batch_size = 8
def encode(self, x):
t = x.shape[2]
frame_batch = self.num_sample_frames_batch_size
num_batches = max(t // frame_batch, 1)
conv_cache = None
enc = []
for i in range(num_batches):
remaining = t % frame_batch
start = frame_batch * i + (0 if i == 0 else remaining)
end = frame_batch * (i + 1) + remaining
chunk, conv_cache = self.encoder(x[:, :, start:end], conv_cache=conv_cache)
enc.append(chunk.to(x.device))
enc = torch.cat(enc, dim=2)
mean, _ = enc.chunk(2, dim=1)
return mean
def decode(self, z):
return self._decode_rolling(z)
def _decode_batched(self, z):
"""Original batched decode - processes 2 latent frames through full decoder."""
t = z.shape[2]
frame_batch = self.num_latent_frames_batch_size
num_batches = max(t // frame_batch, 1)
conv_cache = None
dec = []
for i in range(num_batches):
remaining = t % frame_batch
start = frame_batch * i + (0 if i == 0 else remaining)
end = frame_batch * (i + 1) + remaining
chunk, conv_cache = self.decoder(z[:, :, start:end], conv_cache=conv_cache)
dec.append(chunk.cpu())
return torch.cat(dec, dim=2).to(z.device)
def _decode_rolling(self, z):
"""Rolling decode - processes low-res layers on full tensor, then rolls
through expensive high-res layers in temporal chunks."""
decoder = self.decoder
device = z.device
# Determine which up_blocks have temporal upsample vs spatial-only.
# Temporal up_blocks are cheap (low res), spatial-only are expensive.
temporal_compress_level = int(np.log2(self.temporal_compression_ratio))
split_at = temporal_compress_level # first N up_blocks do temporal upsample
# Phase 1: conv_in + mid_block + temporal up_blocks on full tensor (low/medium res)
x, _ = decoder.conv_in(z)
x, _ = decoder.mid_block(x, None, z)
for i in range(split_at):
x, _ = decoder.up_blocks[i](x, None, z)
# Phase 2: remaining spatial-only up_blocks + norm_out + conv_out in temporal chunks
remaining_blocks = list(range(split_at, len(decoder.up_blocks)))
chunk_size = 4 # pixel frames per chunk through high-res layers
t_expanded = x.shape[2]
if t_expanded <= chunk_size or len(remaining_blocks) == 0:
# Small enough to process in one go
for i in remaining_blocks:
x, _ = decoder.up_blocks[i](x, None, z)
x, _ = decoder.norm_out(x, z)
x = decoder.conv_act(x)
x, _ = decoder.conv_out(x)
return x
# Pre-interpolate z to each spatial resolution used by Phase 2 blocks.
# Uses the exact same interpolation logic as SpatialNorm3D so chunked
# output is identical to non-chunked.
# Determine spatial sizes: run a dummy pass to find feature map sizes,
# or compute from block structure. Simpler: compute from x's current size
# and the known upsample factor (2x per block with upsample).
z_at_res = {} # keyed by (h, w) → pre-interpolated z [B, C, t_expanded, h, w]
h, w = x.shape[3], x.shape[4]
for i in remaining_blocks:
block = decoder.up_blocks[i]
# Resnets operate at current h, w
target = (t_expanded, h, w)
if target not in z_at_res:
z_at_res[target] = _interpolate_zq(z, target)
# If block has upsample, next block's input is 2x spatial
if block.upsamplers is not None:
h, w = h * 2, w * 2
# norm_out operates at final resolution
target = (t_expanded, h, w)
if target not in z_at_res:
z_at_res[target] = _interpolate_zq(z, target)
# Process in temporal chunks
dec_out = []
conv_caches = {}
for chunk_start in range(0, t_expanded, chunk_size):
chunk_end = min(chunk_start + chunk_size, t_expanded)
x_chunk = x[:, :, chunk_start:chunk_end]
for i in remaining_blocks:
block = decoder.up_blocks[i]
cache_key = f"up_block_{i}"
# Get pre-interpolated z at the block's input spatial resolution
res_key = (t_expanded, x_chunk.shape[3], x_chunk.shape[4])
z_chunk = z_at_res[res_key][:, :, chunk_start:chunk_end]
x_chunk, new_cache = block(x_chunk, None, z_chunk, conv_cache=conv_caches.get(cache_key))
conv_caches[cache_key] = new_cache
# norm_out at final resolution
res_key = (t_expanded, x_chunk.shape[3], x_chunk.shape[4])
z_chunk = z_at_res[res_key][:, :, chunk_start:chunk_end]
x_chunk, new_cache = decoder.norm_out(x_chunk, z_chunk, conv_cache=conv_caches.get("norm_out"))
conv_caches["norm_out"] = new_cache
x_chunk = decoder.conv_act(x_chunk)
x_chunk, new_cache = decoder.conv_out(x_chunk, conv_cache=conv_caches.get("conv_out"))
conv_caches["conv_out"] = new_cache
dec_out.append(x_chunk.cpu())
del x
return torch.cat(dec_out, dim=2).to(device)