ViPer / diffusers /models /downsampling.py
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# Copyright 2023 The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
from typing import Optional, Tuple
import torch
import torch.nn as nn
import torch.nn.functional as F
from ..utils import USE_PEFT_BACKEND
from .lora import LoRACompatibleConv
from .normalization import RMSNorm
from .upsampling import upfirdn2d_native
class Downsample1D(nn.Module):
"""A 1D downsampling layer with an optional convolution.
Parameters:
channels (`int`):
number of channels in the inputs and outputs.
use_conv (`bool`, default `False`):
option to use a convolution.
out_channels (`int`, optional):
number of output channels. Defaults to `channels`.
padding (`int`, default `1`):
padding for the convolution.
name (`str`, default `conv`):
name of the downsampling 1D layer.
"""
def __init__(
self,
channels: int,
use_conv: bool = False,
out_channels: Optional[int] = None,
padding: int = 1,
name: str = "conv",
):
super().__init__()
self.channels = channels
self.out_channels = out_channels or channels
self.use_conv = use_conv
self.padding = padding
stride = 2
self.name = name
if use_conv:
self.conv = nn.Conv1d(self.channels, self.out_channels, 3, stride=stride, padding=padding)
else:
assert self.channels == self.out_channels
self.conv = nn.AvgPool1d(kernel_size=stride, stride=stride)
def forward(self, inputs: torch.Tensor) -> torch.Tensor:
assert inputs.shape[1] == self.channels
return self.conv(inputs)
class Downsample2D(nn.Module):
"""A 2D downsampling layer with an optional convolution.
Parameters:
channels (`int`):
number of channels in the inputs and outputs.
use_conv (`bool`, default `False`):
option to use a convolution.
out_channels (`int`, optional):
number of output channels. Defaults to `channels`.
padding (`int`, default `1`):
padding for the convolution.
name (`str`, default `conv`):
name of the downsampling 2D layer.
"""
def __init__(
self,
channels: int,
use_conv: bool = False,
out_channels: Optional[int] = None,
padding: int = 1,
name: str = "conv",
kernel_size=3,
norm_type=None,
eps=None,
elementwise_affine=None,
bias=True,
):
super().__init__()
self.channels = channels
self.out_channels = out_channels or channels
self.use_conv = use_conv
self.padding = padding
stride = 2
self.name = name
conv_cls = nn.Conv2d if USE_PEFT_BACKEND else LoRACompatibleConv
if norm_type == "ln_norm":
self.norm = nn.LayerNorm(channels, eps, elementwise_affine)
elif norm_type == "rms_norm":
self.norm = RMSNorm(channels, eps, elementwise_affine)
elif norm_type is None:
self.norm = None
else:
raise ValueError(f"unknown norm_type: {norm_type}")
if use_conv:
conv = conv_cls(
self.channels, self.out_channels, kernel_size=kernel_size, stride=stride, padding=padding, bias=bias
)
else:
assert self.channels == self.out_channels
conv = nn.AvgPool2d(kernel_size=stride, stride=stride)
# TODO(Suraj, Patrick) - clean up after weight dicts are correctly renamed
if name == "conv":
self.Conv2d_0 = conv
self.conv = conv
elif name == "Conv2d_0":
self.conv = conv
else:
self.conv = conv
def forward(self, hidden_states: torch.FloatTensor, scale: float = 1.0) -> torch.FloatTensor:
assert hidden_states.shape[1] == self.channels
if self.norm is not None:
hidden_states = self.norm(hidden_states.permute(0, 2, 3, 1)).permute(0, 3, 1, 2)
if self.use_conv and self.padding == 0:
pad = (0, 1, 0, 1)
hidden_states = F.pad(hidden_states, pad, mode="constant", value=0)
assert hidden_states.shape[1] == self.channels
if not USE_PEFT_BACKEND:
if isinstance(self.conv, LoRACompatibleConv):
hidden_states = self.conv(hidden_states, scale)
else:
hidden_states = self.conv(hidden_states)
else:
hidden_states = self.conv(hidden_states)
return hidden_states
class FirDownsample2D(nn.Module):
"""A 2D FIR downsampling layer with an optional convolution.
Parameters:
channels (`int`):
number of channels in the inputs and outputs.
use_conv (`bool`, default `False`):
option to use a convolution.
out_channels (`int`, optional):
number of output channels. Defaults to `channels`.
fir_kernel (`tuple`, default `(1, 3, 3, 1)`):
kernel for the FIR filter.
"""
def __init__(
self,
channels: Optional[int] = None,
out_channels: Optional[int] = None,
use_conv: bool = False,
fir_kernel: Tuple[int, int, int, int] = (1, 3, 3, 1),
):
super().__init__()
out_channels = out_channels if out_channels else channels
if use_conv:
self.Conv2d_0 = nn.Conv2d(channels, out_channels, kernel_size=3, stride=1, padding=1)
self.fir_kernel = fir_kernel
self.use_conv = use_conv
self.out_channels = out_channels
def _downsample_2d(
self,
hidden_states: torch.FloatTensor,
weight: Optional[torch.FloatTensor] = None,
kernel: Optional[torch.FloatTensor] = None,
factor: int = 2,
gain: float = 1,
) -> torch.FloatTensor:
"""Fused `Conv2d()` followed by `downsample_2d()`.
Padding is performed only once at the beginning, not between the operations. The fused op is considerably more
efficient than performing the same calculation using standard TensorFlow ops. It supports gradients of
arbitrary order.
Args:
hidden_states (`torch.FloatTensor`):
Input tensor of the shape `[N, C, H, W]` or `[N, H, W, C]`.
weight (`torch.FloatTensor`, *optional*):
Weight tensor of the shape `[filterH, filterW, inChannels, outChannels]`. Grouped convolution can be
performed by `inChannels = x.shape[0] // numGroups`.
kernel (`torch.FloatTensor`, *optional*):
FIR filter of the shape `[firH, firW]` or `[firN]` (separable). The default is `[1] * factor`, which
corresponds to average pooling.
factor (`int`, *optional*, default to `2`):
Integer downsampling factor.
gain (`float`, *optional*, default to `1.0`):
Scaling factor for signal magnitude.
Returns:
output (`torch.FloatTensor`):
Tensor of the shape `[N, C, H // factor, W // factor]` or `[N, H // factor, W // factor, C]`, and same
datatype as `x`.
"""
assert isinstance(factor, int) and factor >= 1
if kernel is None:
kernel = [1] * factor
# setup kernel
kernel = torch.tensor(kernel, dtype=torch.float32)
if kernel.ndim == 1:
kernel = torch.outer(kernel, kernel)
kernel /= torch.sum(kernel)
kernel = kernel * gain
if self.use_conv:
_, _, convH, convW = weight.shape
pad_value = (kernel.shape[0] - factor) + (convW - 1)
stride_value = [factor, factor]
upfirdn_input = upfirdn2d_native(
hidden_states,
torch.tensor(kernel, device=hidden_states.device),
pad=((pad_value + 1) // 2, pad_value // 2),
)
output = F.conv2d(upfirdn_input, weight, stride=stride_value, padding=0)
else:
pad_value = kernel.shape[0] - factor
output = upfirdn2d_native(
hidden_states,
torch.tensor(kernel, device=hidden_states.device),
down=factor,
pad=((pad_value + 1) // 2, pad_value // 2),
)
return output
def forward(self, hidden_states: torch.FloatTensor) -> torch.FloatTensor:
if self.use_conv:
downsample_input = self._downsample_2d(hidden_states, weight=self.Conv2d_0.weight, kernel=self.fir_kernel)
hidden_states = downsample_input + self.Conv2d_0.bias.reshape(1, -1, 1, 1)
else:
hidden_states = self._downsample_2d(hidden_states, kernel=self.fir_kernel, factor=2)
return hidden_states
# downsample/upsample layer used in k-upscaler, might be able to use FirDownsample2D/DirUpsample2D instead
class KDownsample2D(nn.Module):
r"""A 2D K-downsampling layer.
Parameters:
pad_mode (`str`, *optional*, default to `"reflect"`): the padding mode to use.
"""
def __init__(self, pad_mode: str = "reflect"):
super().__init__()
self.pad_mode = pad_mode
kernel_1d = torch.tensor([[1 / 8, 3 / 8, 3 / 8, 1 / 8]])
self.pad = kernel_1d.shape[1] // 2 - 1
self.register_buffer("kernel", kernel_1d.T @ kernel_1d, persistent=False)
def forward(self, inputs: torch.Tensor) -> torch.Tensor:
inputs = F.pad(inputs, (self.pad,) * 4, self.pad_mode)
weight = inputs.new_zeros(
[
inputs.shape[1],
inputs.shape[1],
self.kernel.shape[0],
self.kernel.shape[1],
]
)
indices = torch.arange(inputs.shape[1], device=inputs.device)
kernel = self.kernel.to(weight)[None, :].expand(inputs.shape[1], -1, -1)
weight[indices, indices] = kernel
return F.conv2d(inputs, weight, stride=2)
def downsample_2d(
hidden_states: torch.FloatTensor,
kernel: Optional[torch.FloatTensor] = None,
factor: int = 2,
gain: float = 1,
) -> torch.FloatTensor:
r"""Downsample2D a batch of 2D images with the given filter.
Accepts a batch of 2D images of the shape `[N, C, H, W]` or `[N, H, W, C]` and downsamples each image with the
given filter. The filter is normalized so that if the input pixels are constant, they will be scaled by the
specified `gain`. Pixels outside the image are assumed to be zero, and the filter is padded with zeros so that its
shape is a multiple of the downsampling factor.
Args:
hidden_states (`torch.FloatTensor`)
Input tensor of the shape `[N, C, H, W]` or `[N, H, W, C]`.
kernel (`torch.FloatTensor`, *optional*):
FIR filter of the shape `[firH, firW]` or `[firN]` (separable). The default is `[1] * factor`, which
corresponds to average pooling.
factor (`int`, *optional*, default to `2`):
Integer downsampling factor.
gain (`float`, *optional*, default to `1.0`):
Scaling factor for signal magnitude.
Returns:
output (`torch.FloatTensor`):
Tensor of the shape `[N, C, H // factor, W // factor]`
"""
assert isinstance(factor, int) and factor >= 1
if kernel is None:
kernel = [1] * factor
kernel = torch.tensor(kernel, dtype=torch.float32)
if kernel.ndim == 1:
kernel = torch.outer(kernel, kernel)
kernel /= torch.sum(kernel)
kernel = kernel * gain
pad_value = kernel.shape[0] - factor
output = upfirdn2d_native(
hidden_states,
kernel.to(device=hidden_states.device),
down=factor,
pad=((pad_value + 1) // 2, pad_value // 2),
)
return output