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ComfyUI/comfy/ldm/minimax/vae.py

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Python

# MiniMax H3 video VAE: 3D causal CNN encoder + ViT3D decoder.
import math
import torch
import torch.nn as nn
import torch.nn.functional as F
import comfy.ops
import comfy.quant_ops
import comfy.rmsnorm
from comfy.ldm.modules.attention import optimized_attention
ops = comfy.ops.disable_weight_init
IMAGENET_MEAN = (0.485, 0.456, 0.406)
IMAGENET_STD = (0.229, 0.224, 0.225)
LATENTS_MEAN = [
0.858090341091156, -0.9606591463088989, 1.0661640167236328, -0.5090325474739075,
-0.2727581858634949, -1.3675414323806763, -0.2553254961967468, -0.26907554268836975,
-0.5376840829849243, -0.0464097298681736, 0.6657370328903198, 0.19690127670764923,
-0.5460608005523682, -0.4035342037677765, -0.23683024942874908, 0.25928452610969543,
-0.30133944749832153, 0.211341992020607, -1.1206848621368408, 0.3581933379173279,
-0.04225143790245056, 0.2604829967021942, 0.22864092886447906, 0.7056031823158264,
]
LATENTS_STD = [
1.2223774194717407, 1.2767263650894165, 1.68317747116088865, 1.7549455165863037,
1.5636216402053833, 2.194143533706665, 0.96531379222869875, 1.05698859691619875,
0.841948926448822, 0.7729952931404114, 1.8955937623977661, 0.946841835975647,
0.7996809482574463, 0.44988900423049925, 0.7197399735450745, 0.69362932443618775,
2.961095094680786, 2.7694199085235595, 3.0496184825897215, 2.1088054180145265,
3.276226282119751, 3.1627357006073, 2.28168129920959475, 2.6127843856811525,
]
# 3D causal CNN encoder
class CausalConv3d(ops.Conv3d):
# Reflect spatial padding, causal (zeros, front-only) temporal padding.
def __init__(self, in_channels, out_channels, kernel_size, stride=1, padding=0):
super().__init__(in_channels, out_channels, kernel_size=kernel_size, stride=stride)
self.causal_padding = (padding,) * 3 if isinstance(padding, int) else tuple(padding)
def forward(self, x):
if sum(self.causal_padding) == 0:
return super().forward(x)
x = F.pad(x, (self.causal_padding[2], self.causal_padding[2], self.causal_padding[1], self.causal_padding[1], 0, 0), mode="reflect")
if x.shape[2] == 1:
# single frame: the causal front padding is all zeros truncate the temporal taps instead of convolving zero frames
return super().forward(x, autopad="causal_zero")
x = F.pad(x, (0, 0, 0, 0, self.causal_padding[0] * 2, 0), mode="constant")
return super().forward(x)
class TemporalIsolatedGroupNorm(ops.GroupNorm):
# GroupNorm with statistics computed per frame (time merged into batch).
def forward(self, x):
if x.dim() == 5:
b, c, t, h, w = x.shape
x = x.permute(0, 2, 1, 3, 4).contiguous().view(b * t, c, 1, h, w)
x = super().forward(x)
return x.view(b, t, c, h, w).permute(0, 2, 1, 3, 4).contiguous()
return super().forward(x)
def group_norm_3d(num_channels):
return TemporalIsolatedGroupNorm(num_groups=32, num_channels=num_channels, eps=1e-6, affine=True)
class Downsample3D(nn.Module):
def __init__(self, in_channels, out_channels, time_stride=1, space_stride=2):
super().__init__()
self.space_stride = space_stride
self.conv = CausalConv3d(
in_channels,
out_channels,
kernel_size=3,
padding=(1, 0, 0),
stride=(time_stride, space_stride, space_stride),
)
def forward(self, x):
if self.space_stride == 2:
x = F.pad(x, (0, 1, 0, 1, 0, 0), mode="reflect")
return self.conv(x)
class ResnetBlock3D(nn.Module):
def __init__(self, in_channels, out_channels=None):
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.norm1 = group_norm_3d(in_channels)
self.norm2 = group_norm_3d(out_channels)
self.conv1 = CausalConv3d(in_channels, out_channels, kernel_size=3, padding=1)
self.conv2 = CausalConv3d(out_channels, out_channels, kernel_size=3, padding=1)
if in_channels != out_channels:
self.nin_shortcut = CausalConv3d(in_channels, out_channels, kernel_size=1)
def forward(self, x):
h = self.conv1(F.silu(self.norm1(x), inplace=True))
h = self.conv2(F.silu(self.norm2(h), inplace=True))
if self.in_channels != self.out_channels:
x = self.nin_shortcut(x)
return h.add_(x)
class EncoderFCN3D(nn.Module):
def __init__(self, ch, ch_mult, space_down, time_down, num_res_blocks, in_channels, z_channels, double_z=True):
super().__init__()
self.num_levels = len(ch_mult)
if isinstance(num_res_blocks, int):
num_res_blocks = [num_res_blocks] * self.num_levels
self.num_res_blocks = num_res_blocks
block_mid = [ch * ch_mult[i] for i in range(self.num_levels)]
block_in = [block_mid[0]] + block_mid[:-1]
block_out = block_mid
self.conv_in = CausalConv3d(in_channels, block_in[0], kernel_size=3, padding=1)
self.down = nn.ModuleList()
for i_level in range(self.num_levels):
down = nn.Module()
down.block = nn.ModuleList()
for i in range(self.num_res_blocks[i_level]):
down.block.append(
ResnetBlock3D(
in_channels=block_in[i_level] if i == 0 else block_mid[i_level],
out_channels=block_mid[i_level],
)
)
if space_down[i_level] * time_down[i_level] > 1:
down.downsample = Downsample3D(
block_mid[i_level],
block_out[i_level],
time_stride=time_down[i_level],
space_stride=space_down[i_level],
)
self.down.append(down)
self.norm_out = group_norm_3d(block_out[-1])
self.conv_out = CausalConv3d(
block_out[-1],
2 * z_channels if double_z else z_channels,
kernel_size=3,
padding=1,
)
def forward(self, x):
h = self.conv_in(x)
for i_level in range(self.num_levels):
for i_block in range(self.num_res_blocks[i_level]):
h = self.down[i_level].block[i_block](h)
if hasattr(self.down[i_level], "downsample"):
h = self.down[i_level].downsample(h)
h = F.silu(self.norm_out(h))
return self.conv_out(h)
# ViT3D decoder
def create_token_ids(patch_dims, device, dtype):
coords_list = []
for dim_size in patch_dims:
coords = torch.arange(0.5, dim_size, dtype=dtype, device=device)
coords = coords / dim_size
coords = 2.0 * coords - 1.0
coords_list.append(coords)
coords = torch.stack(torch.meshgrid(*coords_list, indexing="ij"), dim=-1)
return coords.flatten(0, len(patch_dims) - 1).unsqueeze(0)
class RotaryEmbeddingND(nn.Module):
def __init__(self, dim, rotary_base=100.0, n_dim=3):
super().__init__()
self.n_dim = n_dim
self.angle_scale = 2.0 * math.pi
inv_freq = 1 / rotary_base ** torch.arange(0, 1, 2 * n_dim / dim, dtype=torch.float32)
self.register_buffer("inv_freq", inv_freq, persistent=False)
def forward(self, img_ids):
# [B, S, n_dim] -> [B, S, 1, pairs, 2, 2] rotation table for the kitchen split-half rope
angles = (
self.angle_scale
* img_ids[:, :, :, None].float()
* self.inv_freq.to(img_ids.device)[None, None, None, :]
)
angles = angles.flatten(2, 3)
c, s = torch.cos(angles), torch.sin(angles)
table = torch.stack([c, -s, s, c], dim=-1).reshape(*angles.shape[:2], 1, angles.shape[-1], 2, 2)
return table.to(img_ids.dtype)
class FeedForward(nn.Module):
# Gated SiLU FFN.
def __init__(self, dim, mult=4, bias=True):
super().__init__()
inner_dim = dim * mult
self.w1 = ops.Linear(dim, inner_dim * 2, bias=bias)
self.w2 = ops.Linear(inner_dim, dim, bias=bias)
def forward(self, x):
gate, x = self.w1(x).chunk(2, dim=-1)
return self.w2(F.silu(gate).mul_(x))
class Attention(nn.Module):
def __init__(self, heads, dim_head, bias=True, eps=1e-5):
super().__init__()
self.dim_head = dim_head
self.heads = heads
inner_dim = dim_head * heads
self.norm_q = ops.RMSNorm(dim_head, eps=eps, elementwise_affine=False)
self.norm_k = ops.RMSNorm(dim_head, eps=eps, elementwise_affine=False)
self.to_qkv = ops.Linear(inner_dim, inner_dim * 3, bias=bias)
self.to_out = ops.Linear(inner_dim, inner_dim, bias=bias)
def forward(self, x, rotary_pos_emb=None):
batch_size, seq_len, _ = x.shape
qkv = self.to_qkv(x)
qkv = qkv.view(batch_size, seq_len, -1, 3 * self.dim_head)
query, key, value = torch.chunk(qkv, 3, dim=-1)
query = comfy.rmsnorm.rms_norm(query, self.norm_q.weight, self.norm_q.eps)
key = comfy.rmsnorm.rms_norm(key, self.norm_k.weight, self.norm_k.eps)
if rotary_pos_emb is not None:
rot = rotary_pos_emb.shape[-3] * 2
query[..., :rot], key[..., :rot] = comfy.quant_ops.ck.apply_rope_split_half(
query[..., :rot], key[..., :rot], rotary_pos_emb)
out = optimized_attention(query.transpose(1, 2), key.transpose(1, 2), value.transpose(1, 2),
self.heads, skip_reshape=True).nan_to_num_(0.0)
return self.to_out(out)
class TransformerBlock(nn.Module):
def __init__(self, heads, dim_head, bias=True, eps=1e-5):
super().__init__()
dim = heads * dim_head
self.norm1 = ops.RMSNorm(dim, elementwise_affine=True, eps=eps)
self.attn = Attention(heads=heads, dim_head=dim_head, bias=bias, eps=eps)
self.scale1 = nn.Parameter(torch.empty(dim))
self.norm2 = ops.RMSNorm(dim, elementwise_affine=True, eps=eps)
self.ff = FeedForward(dim=dim, bias=bias)
self.scale2 = nn.Parameter(torch.empty(dim))
def forward(self, x, rotary_pos_emb=None):
x = x.addcmul_(self.attn(comfy.rmsnorm.rms_norm(x, self.norm1.weight, self.norm1.eps), rotary_pos_emb), comfy.ops.cast_to_input(self.scale1, x))
return x.addcmul_(self.ff(comfy.rmsnorm.rms_norm(x, self.norm2.weight, self.norm2.eps)), comfy.ops.cast_to_input(self.scale2, x))
class ViT3DDecoder(nn.Module):
def __init__(self, patch_size=16, patch_size_t=4, in_channels=24, out_channels=3, num_layers=36, heads=32, dim_head=64, rope_theta=100.0,
rope_dim_ratio=0.75, bias=True, eps=1e-5, num_register_tokens=4):
super().__init__()
dim = heads * dim_head
self.patch_size = patch_size
self.patch_size_t = patch_size_t
self.out_channels = out_channels
self.num_register_tokens = num_register_tokens
self.pos_embed = RotaryEmbeddingND(int(dim_head * rope_dim_ratio), rope_theta, n_dim=3)
self.x_embedder = ops.Linear(in_channels, dim)
self.register_tokens = nn.Parameter(torch.empty(1, num_register_tokens, dim))
# unused at inference; kept so the checkpoint loads without leftover keys
self.register_buffer("mask_token", torch.empty(1, 1, dim))
self.transformer_blocks = nn.ModuleList(
[TransformerBlock(heads=heads, dim_head=dim_head, bias=bias, eps=eps)
for _ in range(num_layers)]
)
self.norm_out = ops.LayerNorm(dim, elementwise_affine=True, eps=eps)
self.proj_out = ops.Linear(dim, out_channels * patch_size_t * patch_size * patch_size)
def forward(self, x):
B, C, latent_T, latent_H, latent_W = x.shape
h = self.x_embedder(x.flatten(2).transpose(1, 2)) # [B, T*H*W, C]
num_patches = h.shape[1]
num_suffix = 1 + self.num_register_tokens
h = torch.cat([h, comfy.ops.cast_to_input(self.register_tokens, h).expand(B, -1, -1), torch.zeros_like(h[:, 0:1, :])], dim=1)
img_ids = create_token_ids((latent_T, latent_H, latent_W), x.device, x.dtype).expand(B, -1, -1)
suffix_ids = torch.zeros((B, num_suffix, 3), device=x.device, dtype=img_ids.dtype)
img_ids = torch.cat([img_ids, suffix_ids], dim=1)
rotary_pos_emb = self.pos_embed(img_ids)
for block in self.transformer_blocks:
h = block(h, rotary_pos_emb)
output = self.proj_out(self.norm_out(h))
output = output[:, :num_patches, :]
output = output.view(
B, latent_T, latent_H, latent_W,
self.out_channels, self.patch_size_t, self.patch_size, self.patch_size,
)
output = output.permute(0, 4, 1, 5, 2, 6, 3, 7).contiguous()
output = output.reshape(
B, self.out_channels,
latent_T * self.patch_size_t,
latent_H * self.patch_size,
latent_W * self.patch_size,
)
return output
# Full VAE
class MiniMaxH3VideoVAE(nn.Module):
def __init__(
self,
in_channels=3,
out_ch=3,
ch=128,
embed_dim=24,
z_channels=24,
ch_mult=(1, 2, 2, 4, 4, 8),
num_res_blocks=2,
space_down=(2, 2, 2, 2, 1, 1),
time_down=(1, 2, 2, 1, 1, 1),
clip_length=17,
token_drop=3,
tile_size=256,
tile_overlap_min=64,
tiling=True,
):
super().__init__()
self.vae_ratio = int(math.prod(space_down))
self.vae_ratio_t = int(math.prod(time_down))
# temporal chunking parameters
self.clip_length = clip_length
self.token_drop = token_drop
self.frame_pre_padding = (-clip_length) % self.vae_ratio_t
self.tokens_chunk_size = math.ceil(clip_length / self.vae_ratio_t)
self.token_overlap = (-token_drop) % self.tokens_chunk_size
self.frame_overlap = max(self.token_overlap * self.vae_ratio_t - self.frame_pre_padding, 0)
# spatial tiling parameters
self.tiling = tiling
self.tile_size = tile_size
self.tile_overlap_min = tile_overlap_min
self.encoder = EncoderFCN3D(
ch=ch,
ch_mult=list(ch_mult),
space_down=list(space_down),
time_down=list(time_down),
num_res_blocks=num_res_blocks,
in_channels=in_channels,
z_channels=z_channels,
double_z=True,
)
self.quant_conv = ops.Conv3d(z_channels * 2, 2 * embed_dim, 1)
self.post_quant_conv = ops.Conv3d(embed_dim, z_channels, 1)
self.decoder = ViT3DDecoder(
patch_size=self.vae_ratio,
patch_size_t=self.vae_ratio_t,
in_channels=z_channels,
out_channels=out_ch,
)
self.register_buffer("latents_mean", torch.tensor(LATENTS_MEAN))
self.register_buffer("latents_std", torch.tensor(LATENTS_STD))
self.register_buffer("pixel_mean", torch.tensor(IMAGENET_MEAN).view(1, 3, 1, 1, 1), persistent=False)
self.register_buffer("pixel_std", torch.tensor(IMAGENET_STD).view(1, 3, 1, 1, 1), persistent=False)
# single-shot forward
def _encode_moments(self, x):
return self.quant_conv(self.encoder(x))
def _decode_pixels(self, z):
return self.decoder(self.post_quant_conv(z))
def _adaptive_encode(self, x):
if self.tiling:
return self.tiled_encode(x)
return self._encode_moments(x)
def _adaptive_decode(self, z):
if self.tiling:
return self.tiled_decode(z)
return self._decode_pixels(z)
# spatial tiling
def split_tiles(self, input_len):
tile_size = self.tile_size
if tile_size >= input_len:
return [0], [input_len], []
N = math.ceil(input_len / tile_size)
while True:
overlaps = [self.tile_overlap_min] * (N - 1)
remaining = tile_size * N - sum(overlaps) - input_len
if remaining < 0:
N += 1
else:
break
remaining_units = remaining // self.vae_ratio
for i in range(remaining_units):
overlaps[i % (N - 1)] += self.vae_ratio
tile_start_idx = [0]
for i in range(N - 1):
tile_start_idx.append(tile_start_idx[-1] + tile_size - overlaps[i])
return tile_start_idx, [tile_size] * N, overlaps
def blend(self, a, b, blend_extent, dim):
blend_extent = min(a.shape[dim], b.shape[dim], blend_extent)
positions = torch.arange(blend_extent, device=b.device, dtype=b.dtype)
weight_a = 1 - positions / blend_extent
weight_b = positions / blend_extent
shape = [1] * a.ndim
shape[dim] = blend_extent
weight_a = weight_a.view(shape)
weight_b = weight_b.view(shape)
slice_a = [slice(None)] * a.ndim
slice_a[dim] = slice(-blend_extent, None)
slice_b = [slice(None)] * b.ndim
slice_b[dim] = slice(0, blend_extent)
blended = a[tuple(slice_a)] * weight_a + b[tuple(slice_b)] * weight_b
if blend_extent < b.shape[dim]:
slice_b_rest = [slice(None)] * b.ndim
slice_b_rest[dim] = slice(blend_extent, None)
return torch.cat([blended, b[tuple(slice_b_rest)]], dim=dim)
return blended
def tiled_encode(self, x):
height, width = x.shape[-2], x.shape[-1]
y_idx, y_len, y_overlap = self.split_tiles(height)
x_idx, x_len, x_overlap = self.split_tiles(width)
rows = []
for i_pos, i_len in zip(y_idx, y_len):
row = []
for j_pos, j_len in zip(x_idx, x_len):
tile = x[..., i_pos:i_pos + i_len, j_pos:j_pos + j_len]
row.append(self._encode_moments(tile))
rows.append(row)
latent_y_overlap = [o // self.vae_ratio for o in y_overlap]
latent_x_overlap = [o // self.vae_ratio for o in x_overlap]
result_rows = []
for i, row in enumerate(rows):
result_row = []
for j, tile in enumerate(row):
if i > 0:
tile = self.blend(rows[i - 1][j], tile, latent_y_overlap[i - 1], dim=-2)
if j > 0:
tile = self.blend(row[j - 1], tile, latent_x_overlap[j - 1], dim=-1)
if i < len(rows) - 1:
tile = tile[..., :-latent_y_overlap[i], :]
if j < len(row) - 1:
tile = tile[..., :, :-latent_x_overlap[j]]
result_row.append(tile)
result_rows.append(torch.cat(result_row, dim=-1))
return torch.cat(result_rows, dim=-2)
def tiled_decode(self, z):
height, width = z.shape[-2] * self.vae_ratio, z.shape[-1] * self.vae_ratio
y_idx, y_len, y_overlap = self.split_tiles(height)
x_idx, x_len, x_overlap = self.split_tiles(width)
# Blended tiles are written straight into a pre-allocated canvas.
canvas = None
row_tails = []
out_y = 0
for i, (i_pos, i_len) in enumerate(zip(y_idx, y_len)):
zi, zl = i_pos // self.vae_ratio, i_len // self.vae_ratio
new_tails = []
left_tail = None
out_x = 0
for j, (j_pos, j_len) in enumerate(zip(x_idx, x_len)):
zj, zw = j_pos // self.vae_ratio, j_len // self.vae_ratio
tile = self._decode_pixels(z[..., zi:zi + zl, zj:zj + zw])
if i < len(y_idx) - 1:
new_tails.append(tile[..., -y_overlap[i]:, :].clone())
next_left_tail = tile[..., :, -x_overlap[j]:].clone() if j < len(x_idx) - 1 else None
if i > 0:
tile = self.blend(row_tails[j], tile, y_overlap[i - 1], dim=-2)
if j > 0:
tile = self.blend(left_tail, tile, x_overlap[j - 1], dim=-1)
left_tail = next_left_tail
if i < len(y_idx) - 1:
tile = tile[..., :-y_overlap[i], :]
if j < len(x_idx) - 1:
tile = tile[..., :, :-x_overlap[j]]
if canvas is None:
canvas = torch.empty(*tile.shape[:-2], height, width, dtype=tile.dtype, device=tile.device)
canvas[..., out_y:out_y + tile.shape[-2], out_x:out_x + tile.shape[-1]].copy_(tile)
out_x += tile.shape[-1]
row_tails = new_tails
out_y += tile.shape[-2]
return canvas
# temporal chunking
def encode_temporal(self, x):
if x.shape[2] % self.clip_length != 0:
pad_size = (-x.shape[2]) % self.clip_length
pad_frames = x[:, :, -1:].repeat(1, 1, pad_size, 1, 1)
x = torch.cat([x, pad_frames], dim=2)
num_chunks = x.shape[2] // self.clip_length
z_list = []
for i in range(num_chunks):
clip_x = x[:, :, i * self.clip_length:(i + 1) * self.clip_length, :, :]
z_list.append(self._adaptive_encode(clip_x))
z = torch.cat(z_list, dim=2)
if self.token_drop > 0:
z = z[:, :, :-self.token_drop]
return z
def _decode_temporal_pad_frames(self, z_len, pad_tokens):
if pad_tokens <= 0:
return 0
intra_tail = self.clip_length % self.vae_ratio_t
if intra_tail == 0:
return pad_tokens * self.vae_ratio_t
z_len_before_pad = z_len - pad_tokens
return sum(
(intra_tail if (z_len_before_pad + k) % self.tokens_chunk_size == 0
else self.vae_ratio_t)
for k in range(pad_tokens)
)
def _decode_temporal_frame_plan(self, z_len, num_chunks, pad_tokens):
chunk_dec = self.tokens_chunk_size * self.vae_ratio_t
split_count = int(self.token_drop > 0) + 1
total_frames = 0
final_overlap_frames = 0
for i in range(num_chunks):
t_start_idx = i * self.tokens_chunk_size
t_end_idx = t_start_idx + self.tokens_chunk_size + self.token_overlap
clip_token_len = max(0, min(t_end_idx, z_len) - min(t_start_idx, z_len))
clip_frame_len = clip_token_len * self.vae_ratio_t
for j in range(split_count):
f_start_idx = j * chunk_dec
f_end_idx = min(f_start_idx + chunk_dec, clip_frame_len)
chunk_frames = max(0, f_end_idx - f_start_idx - self.frame_pre_padding)
if j == 0:
total_frames += chunk_frames
else:
final_overlap_frames = chunk_frames
total_frames += final_overlap_frames
return total_frames - self._decode_temporal_pad_frames(z_len, pad_tokens)
def decode_temporal(self, z):
chunk_dec = self.tokens_chunk_size * self.vae_ratio_t
split_count = int(self.token_drop > 0) + 1
pseudo_total_tokens = z.shape[2] + self.token_drop
pad_tokens = 0
remainder = pseudo_total_tokens % self.tokens_chunk_size
if remainder != 0:
pad_tokens = self.tokens_chunk_size - remainder
pseudo_total_tokens += pad_tokens
num_chunks = pseudo_total_tokens // self.tokens_chunk_size - int(self.token_drop > 0)
if num_chunks < 1:
# too few tokens for one chunk (e.g. T_lat == 2): pad one extra chunk
pad_tokens += self.tokens_chunk_size
num_chunks += 1
if pad_tokens > 0:
pad_z = z[:, :, -1:, :, :].repeat(1, 1, pad_tokens, 1, 1)
z = torch.cat([z, pad_z], dim=2)
output_frames = self._decode_temporal_frame_plan(z.shape[2], num_chunks, pad_tokens)
dec = None
dec_overlap = None
write_pos = 0
def write_part(part):
nonlocal dec, write_pos
part_frames = part.shape[2]
if part_frames <= 0:
return
if dec is None:
out_shape = list(part.shape)
out_shape[2] = output_frames
dec = torch.empty(out_shape, dtype=part.dtype, device=part.device)
copy_frames = min(part_frames, max(0, dec.shape[2] - write_pos))
if copy_frames > 0:
dec[:, :, write_pos:write_pos + copy_frames, :, :].copy_(
part[:, :, :copy_frames, :, :]
)
write_pos += copy_frames
for i in range(num_chunks):
t_start_idx = i * self.tokens_chunk_size
t_end_idx = t_start_idx + self.tokens_chunk_size + self.token_overlap
clip_z = z[:, :, t_start_idx:t_end_idx, :, :]
clip_dec = self._adaptive_decode(clip_z)
for j in range(split_count):
f_start_idx = j * chunk_dec
f_end_idx = min(f_start_idx + chunk_dec, clip_dec.shape[2])
clip_dec_chunk = clip_dec[:, :, f_start_idx:f_end_idx, :, :]
clip_dec_chunk = clip_dec_chunk[:, :, self.frame_pre_padding:, :, :]
if j == 0:
if dec_overlap is not None:
clip_dec_chunk = self.blend(
dec_overlap, clip_dec_chunk, self.frame_overlap, dim=-3
)
dec_overlap = None
write_part(clip_dec_chunk)
else:
dec_overlap = clip_dec_chunk.contiguous()
if i == num_chunks - 1 and dec_overlap is not None:
write_part(dec_overlap)
dec_overlap = None
del clip_dec, clip_z
return dec
def encode(self, x):
# x: [B, 3, T, H, W] in [-1, 1] -> normalized latents [B, 24, T_lat, H/16, W/16]
if x.ndim == 4:
x = x.unsqueeze(2)
x = x.add(1.0).mul_(0.5).sub_(self.pixel_mean.to(x)).div_(self.pixel_std.to(x))
if x.shape[2] == 1:
moments = self._adaptive_encode(x)
moments = moments[:, :, -1:, :, :]
else:
moments = self.encode_temporal(x)
mean = torch.chunk(moments.float(), 2, dim=1)[0]
latents_mean = self.latents_mean.view(1, -1, 1, 1, 1).to(mean)
latents_std = self.latents_std.view(1, -1, 1, 1, 1).to(mean)
return (mean - latents_mean) / latents_std
def encode_tiled(self, x, **kwargs):
# tiling is always on internally with the reference's semantic tile sizes, ignore tiling fallbacks
return self.encode(x)
def decode_tiled(self, z, **kwargs):
return self.decode(z)
def decode(self, z):
# z: [B, 24, T_lat, H_lat, W_lat] normalized latents -> pixels [B, 3, T, H, W] in [-1, 1]
latents_mean = self.latents_mean.view(1, -1, 1, 1, 1).to(z)
latents_std = self.latents_std.view(1, -1, 1, 1, 1).to(z)
z = z * latents_std + latents_mean
if z.shape[2] == 1:
dec = self._adaptive_decode(z)
dec = dec[:, :, -1:, :, :]
else:
dec = self.decode_temporal(z)
dec = dec.float()
dec.mul_(self.pixel_std.to(dec)).add_(self.pixel_mean.to(dec)).clamp_(0.0, 1.0).mul_(2.0).sub_(1.0)
return dec