106 lines
3.2 KiB
Python
106 lines
3.2 KiB
Python
from abc import ABC, abstractmethod
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from typing import Tuple
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import torch
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from einops import rearrange
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from torch import Tensor
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def append_dims(x: torch.Tensor, target_dims: int) -> torch.Tensor:
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"""Appends dimensions to the end of a tensor until it has target_dims dimensions."""
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dims_to_append = target_dims - x.ndim
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if dims_to_append < 0:
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raise ValueError(
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f"input has {x.ndim} dims but target_dims is {target_dims}, which is less"
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)
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elif dims_to_append == 0:
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return x
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return x[(...,) + (None,) * dims_to_append]
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class Patchifier(ABC):
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def __init__(self, patch_size: int):
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super().__init__()
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self._patch_size = (1, patch_size, patch_size)
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@abstractmethod
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def patchify(
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self, latents: Tensor, frame_rates: Tensor, scale_grid: bool
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) -> Tuple[Tensor, Tensor]:
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pass
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@abstractmethod
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def unpatchify(
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self,
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latents: Tensor,
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output_height: int,
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output_width: int,
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output_num_frames: int,
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out_channels: int,
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) -> Tuple[Tensor, Tensor]:
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pass
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@property
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def patch_size(self):
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return self._patch_size
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def get_grid(
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self, orig_num_frames, orig_height, orig_width, batch_size, scale_grid, device
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):
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f = orig_num_frames // self._patch_size[0]
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h = orig_height // self._patch_size[1]
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w = orig_width // self._patch_size[2]
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grid_h = torch.arange(h, dtype=torch.float32, device=device)
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grid_w = torch.arange(w, dtype=torch.float32, device=device)
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grid_f = torch.arange(f, dtype=torch.float32, device=device)
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grid = torch.meshgrid(grid_f, grid_h, grid_w)
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grid = torch.stack(grid, dim=0)
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grid = grid.unsqueeze(0).repeat(batch_size, 1, 1, 1, 1)
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if scale_grid is not None:
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for i in range(3):
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if isinstance(scale_grid[i], Tensor):
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scale = append_dims(scale_grid[i], grid.ndim - 1)
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else:
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scale = scale_grid[i]
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grid[:, i, ...] = grid[:, i, ...] * scale * self._patch_size[i]
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grid = rearrange(grid, "b c f h w -> b c (f h w)", b=batch_size)
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return grid
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class SymmetricPatchifier(Patchifier):
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def patchify(
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self,
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latents: Tensor,
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) -> Tuple[Tensor, Tensor]:
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latents = rearrange(
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latents,
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"b c (f p1) (h p2) (w p3) -> b (f h w) (c p1 p2 p3)",
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p1=self._patch_size[0],
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p2=self._patch_size[1],
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p3=self._patch_size[2],
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)
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return latents
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def unpatchify(
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self,
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latents: Tensor,
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output_height: int,
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output_width: int,
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output_num_frames: int,
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out_channels: int,
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) -> Tuple[Tensor, Tensor]:
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output_height = output_height // self._patch_size[1]
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output_width = output_width // self._patch_size[2]
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latents = rearrange(
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latents,
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"b (f h w) (c p q) -> b c f (h p) (w q) ",
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f=output_num_frames,
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h=output_height,
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w=output_width,
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p=self._patch_size[1],
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q=self._patch_size[2],
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)
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return latents
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