Vendor minimal diffsynth subset for FlashVSR inference (full/tiny pipelines, v1 and v1.1 checkpoints auto-downloaded from HuggingFace). Includes segment-based processing with temporal overlap and crossfade blending for bounded RAM on long videos. Nodes: Load FlashVSR Model, FlashVSR Upscale, FlashVSR Segment Upscale. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
321 lines
13 KiB
Python
321 lines
13 KiB
Python
#!/usr/bin/env python3
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"""
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Tiny AutoEncoder for Hunyuan Video (Decoder-only, pruned)
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- Encoder removed
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- Transplant/widening helpers removed
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- Deepening (IdentityConv2d+ReLU) is now built into the decoder structure itself
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"""
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import torch
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import torch.nn as nn
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import torch.nn.functional as F
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from tqdm.auto import tqdm
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from collections import namedtuple
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from einops import rearrange
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import torch.nn.init as init
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DecoderResult = namedtuple("DecoderResult", ("frame", "memory"))
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TWorkItem = namedtuple("TWorkItem", ("input_tensor", "block_index"))
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# ----------------------------
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# Utility / building blocks
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# ----------------------------
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class IdentityConv2d(nn.Conv2d):
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"""Same-shape Conv2d initialized to identity (Dirac)."""
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def __init__(self, C, kernel_size=3, bias=False):
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pad = kernel_size // 2
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super().__init__(C, C, kernel_size, padding=pad, bias=bias)
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with torch.no_grad():
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init.dirac_(self.weight)
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if self.bias is not None:
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self.bias.zero_()
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def conv(n_in, n_out, **kwargs):
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return nn.Conv2d(n_in, n_out, 3, padding=1, **kwargs)
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class Clamp(nn.Module):
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def forward(self, x):
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return torch.tanh(x / 3) * 3
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class MemBlock(nn.Module):
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def __init__(self, n_in, n_out):
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super().__init__()
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self.conv = nn.Sequential(
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conv(n_in * 2, n_out), nn.ReLU(inplace=True),
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conv(n_out, n_out), nn.ReLU(inplace=True),
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conv(n_out, n_out)
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)
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self.skip = nn.Conv2d(n_in, n_out, 1, bias=False) if n_in != n_out else nn.Identity()
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self.act = nn.ReLU(inplace=True)
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def forward(self, x, past):
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return self.act(self.conv(torch.cat([x, past], 1)) + self.skip(x))
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class TPool(nn.Module):
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def __init__(self, n_f, stride):
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super().__init__()
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self.stride = stride
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self.conv = nn.Conv2d(n_f*stride, n_f, 1, bias=False)
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def forward(self, x):
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_NT, C, H, W = x.shape
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return self.conv(x.reshape(-1, self.stride * C, H, W))
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class TGrow(nn.Module):
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def __init__(self, n_f, stride):
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super().__init__()
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self.stride = stride
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self.conv = nn.Conv2d(n_f, n_f*stride, 1, bias=False)
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def forward(self, x):
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_NT, C, H, W = x.shape
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x = self.conv(x)
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return x.reshape(-1, C, H, W)
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class PixelShuffle3d(nn.Module):
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def __init__(self, ff, hh, ww):
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super().__init__()
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self.ff = ff
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self.hh = hh
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self.ww = ww
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def forward(self, x):
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# x: (B, C, F, H, W)
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B, C, F, H, W = x.shape
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if F % self.ff != 0:
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first_frame = x[:, :, 0:1, :, :].repeat(1, 1, self.ff - F % self.ff, 1, 1)
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x = torch.cat([first_frame, x], dim=2)
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return rearrange(
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x,
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'b c (f ff) (h hh) (w ww) -> b (c ff hh ww) f h w',
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ff=self.ff, hh=self.hh, ww=self.ww
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).transpose(1, 2)
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# ----------------------------
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# Generic NTCHW graph executor (kept; used by decoder)
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# ----------------------------
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def apply_model_with_memblocks(model, x, parallel, show_progress_bar, mem=None):
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"""
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Apply a sequential model with memblocks to the given input.
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Args:
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- model: nn.Sequential of blocks to apply
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- x: input data, of dimensions NTCHW
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- parallel: if True, parallelize over timesteps (fast but uses O(T) memory)
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if False, each timestep will be processed sequentially (slow but uses O(1) memory)
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- show_progress_bar: if True, enables tqdm progressbar display
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Returns NTCHW tensor of output data.
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"""
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assert x.ndim == 5, f"TAEHV operates on NTCHW tensors, but got {x.ndim}-dim tensor"
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N, T, C, H, W = x.shape
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if parallel:
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x = x.reshape(N*T, C, H, W)
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for b in tqdm(model, disable=not show_progress_bar):
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if isinstance(b, MemBlock):
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NT, C, H, W = x.shape
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T = NT // N
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_x = x.reshape(N, T, C, H, W)
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mem = F.pad(_x, (0,0,0,0,0,0,1,0), value=0)[:,:T].reshape(x.shape)
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x = b(x, mem)
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else:
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x = b(x)
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NT, C, H, W = x.shape
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T = NT // N
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x = x.view(N, T, C, H, W)
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else:
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out = []
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work_queue = [TWorkItem(xt, 0) for t, xt in enumerate(x.reshape(N, T * C, H, W).chunk(T, dim=1))]
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progress_bar = tqdm(range(T), disable=not show_progress_bar)
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while work_queue:
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xt, i = work_queue.pop(0)
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if i == 0:
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progress_bar.update(1)
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if i == len(model):
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out.append(xt)
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else:
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b = model[i]
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if isinstance(b, MemBlock):
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if mem[i] is None:
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xt_new = b(xt, xt * 0)
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mem[i] = xt
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else:
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xt_new = b(xt, mem[i])
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mem[i].copy_(xt)
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work_queue.insert(0, TWorkItem(xt_new, i+1))
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elif isinstance(b, TPool):
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if mem[i] is None:
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mem[i] = []
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mem[i].append(xt)
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if len(mem[i]) > b.stride:
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raise ValueError("TPool internal state invalid.")
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elif len(mem[i]) == b.stride:
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N_, C_, H_, W_ = xt.shape
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xt = b(torch.cat(mem[i], 1).view(N_*b.stride, C_, H_, W_))
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mem[i] = []
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work_queue.insert(0, TWorkItem(xt, i+1))
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elif isinstance(b, TGrow):
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xt = b(xt)
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NT, C_, H_, W_ = xt.shape
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for xt_next in reversed(xt.view(N, b.stride*C_, H_, W_).chunk(b.stride, 1)):
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work_queue.insert(0, TWorkItem(xt_next, i+1))
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else:
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xt = b(xt)
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work_queue.insert(0, TWorkItem(xt, i+1))
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progress_bar.close()
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x = torch.stack(out, 1)
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return x, mem
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# ----------------------------
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# Decoder-only TAEHV
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# ----------------------------
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class TAEHV(nn.Module):
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image_channels = 3
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def __init__(
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self,
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checkpoint_path="taehv.pth",
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decoder_time_upscale=(True, True),
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decoder_space_upscale=(True, True, True),
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channels = [256, 128, 64, 64],
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latent_channels = 16
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):
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"""Initialize TAEHV (decoder-only) with built-in deepening after every ReLU.
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Deepening config: how_many_each=1, k=3 (fixed as requested).
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"""
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super().__init__()
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self.latent_channels = latent_channels
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n_f = channels
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self.frames_to_trim = 2**sum(decoder_time_upscale) - 1
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# Build the decoder "skeleton"
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base_decoder = nn.Sequential(
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Clamp(), conv(self.latent_channels, n_f[0]), nn.ReLU(inplace=True),
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MemBlock(n_f[0], n_f[0]), MemBlock(n_f[0], n_f[0]), MemBlock(n_f[0], n_f[0]),
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nn.Upsample(scale_factor=2 if decoder_space_upscale[0] else 1),
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TGrow(n_f[0], 1),
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conv(n_f[0], n_f[1], bias=False),
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MemBlock(n_f[1], n_f[1]), MemBlock(n_f[1], n_f[1]), MemBlock(n_f[1], n_f[1]),
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nn.Upsample(scale_factor=2 if decoder_space_upscale[1] else 1),
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TGrow(n_f[1], 2 if decoder_time_upscale[0] else 1),
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conv(n_f[1], n_f[2], bias=False),
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MemBlock(n_f[2], n_f[2]), MemBlock(n_f[2], n_f[2]), MemBlock(n_f[2], n_f[2]),
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nn.Upsample(scale_factor=2 if decoder_space_upscale[2] else 1),
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TGrow(n_f[2], 2 if decoder_time_upscale[1] else 1),
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conv(n_f[2], n_f[3], bias=False),
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nn.ReLU(inplace=True), conv(n_f[3], TAEHV.image_channels),
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)
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# Inline deepening: insert (IdentityConv2d(k=3) + ReLU) after every ReLU
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self.decoder = self._apply_identity_deepen(base_decoder, how_many_each=1, k=3)
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self.pixel_shuffle = PixelShuffle3d(4, 8, 8)
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if checkpoint_path is not None:
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missing_keys = self.load_state_dict(
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self.patch_tgrow_layers(torch.load(checkpoint_path, map_location="cpu", weights_only=True)),
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strict=False
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)
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print('missing_keys', missing_keys)
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# Initialize decoder mem state
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self.mem = [None] * len(self.decoder)
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@staticmethod
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def _apply_identity_deepen(decoder: nn.Sequential, how_many_each=1, k=3) -> nn.Sequential:
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"""Return a new Sequential where every nn.ReLU is followed by how_many_each*(IdentityConv2d(k)+ReLU)."""
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new_layers = []
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for b in decoder:
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new_layers.append(b)
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if isinstance(b, nn.ReLU):
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# Deduce channel count from preceding layer
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C = None
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if len(new_layers) >= 2 and isinstance(new_layers[-2], nn.Conv2d):
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C = new_layers[-2].out_channels
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elif len(new_layers) >= 2 and isinstance(new_layers[-2], MemBlock):
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C = new_layers[-2].conv[-1].out_channels
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if C is not None:
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for _ in range(how_many_each):
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new_layers.append(IdentityConv2d(C, kernel_size=k, bias=False))
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new_layers.append(nn.ReLU(inplace=True))
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return nn.Sequential(*new_layers)
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def patch_tgrow_layers(self, sd):
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"""Patch TGrow layers to use a smaller kernel if needed (decoder-only)."""
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new_sd = self.state_dict()
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for i, layer in enumerate(self.decoder):
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if isinstance(layer, TGrow):
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key = f"decoder.{i}.conv.weight"
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if key in sd and sd[key].shape[0] > new_sd[key].shape[0]:
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sd[key] = sd[key][-new_sd[key].shape[0]:]
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return sd
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def decode_video(self, x, parallel=True, show_progress_bar=False, cond=None):
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"""Decode a sequence of frames from latents.
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x: NTCHW latent tensor; returns NTCHW RGB in ~[0, 1].
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"""
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trim_flag = self.mem[-8] is None # keeps original relative check
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if cond is not None:
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x = torch.cat([self.pixel_shuffle(cond), x], dim=2)
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x, self.mem = apply_model_with_memblocks(self.decoder, x, parallel, show_progress_bar, mem=self.mem)
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if trim_flag:
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return x[:, self.frames_to_trim:]
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return x
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def forward(self, *args, **kwargs):
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raise NotImplementedError("Decoder-only model: call decode_video(...) instead.")
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def clean_mem(self):
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self.mem = [None] * len(self.decoder)
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class DotDict(dict):
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__getattr__ = dict.__getitem__
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__setattr__ = dict.__setitem__
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class TAEW2_1DiffusersWrapper(nn.Module):
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def __init__(self, pretrained_path=None, channels = [256, 128, 64, 64]):
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super().__init__()
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self.dtype = torch.bfloat16
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self.device = "cuda"
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self.taehv = TAEHV(pretrained_path, channels = channels).to(self.dtype)
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self.temperal_downsample = [True, True, False] # [sic]
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self.config = DotDict(scaling_factor=1.0, latents_mean=torch.zeros(16), z_dim=16, latents_std=torch.ones(16))
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def decode(self, latents, return_dict=None):
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n, c, t, h, w = latents.shape
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return (self.taehv.decode_video(latents.transpose(1, 2), parallel=False).transpose(1, 2).mul_(2).sub_(1),)
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def stream_decode_with_cond(self, latents, tiled=False, cond=None):
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n, c, t, h, w = latents.shape
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return self.taehv.decode_video(latents.transpose(1, 2), parallel=False, cond=cond).transpose(1, 2).mul_(2).sub_(1)
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def clean_mem(self):
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self.taehv.clean_mem()
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# ----------------------------
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# Simplified builder (no small, no transplant, no post-hoc deepening)
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# ----------------------------
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def build_tcdecoder(new_channels = [512, 256, 128, 128],
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device="cuda",
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dtype=torch.bfloat16,
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new_latent_channels=None):
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"""
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构建“更宽”的 decoder;深度增强(IdentityConv2d+ReLU)已在 TAEHV 内部完成。
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- 不创建 small / 不做移植
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- base_ckpt_path 参数保留但不使用(接口兼容)
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返回:big (单个模型)
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"""
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if new_latent_channels is not None:
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big = TAEHV(checkpoint_path=None, channels=new_channels, latent_channels=new_latent_channels).to(device).to(dtype).train()
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else:
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big = TAEHV(checkpoint_path=None, channels=new_channels).to(device).to(dtype).train()
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big.clean_mem()
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return big
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