enable i2i with highres fix, add slicing VAE

library/slicing_vae.py

@@ -0,0 +1,665 @@
+# Modified from Diffusers to reduce VRAM usage
+
+# Copyright 2022 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 dataclasses import dataclass
+from typing import Optional, Tuple, Union
+
+import numpy as np
+import torch
+import torch.nn as nn
+
+
+from diffusers.configuration_utils import ConfigMixin, register_to_config
+from diffusers.modeling_utils import ModelMixin
+from diffusers.utils import BaseOutput
+from diffusers.models.unet_2d_blocks import UNetMidBlock2D, get_down_block, get_up_block, ResnetBlock2D
+from diffusers.models.vae import DecoderOutput, Encoder, AutoencoderKLOutput, DiagonalGaussianDistribution
+
+
+def slice_h(x, num_slices):
+    # slice with pad 1 both sides: to eliminate side effect of padding of conv2d
+    # Conv2dのpaddingの副作用を排除するために、両側にpad 1しながらHをスライスする
+    # NCHWでもNHWCでもどちらでも動く
+    size = (x.shape[2] + num_slices - 1) // num_slices
+    sliced = []
+    for i in range(num_slices):
+        if i == 0:
+            sliced.append(x[:, :, : size + 1, :])
+        else:
+            end = size * (i + 1) + 1
+            if x.shape[2] - end < 3:  # if the last slice is too small, use the rest of the tensor 最後が細すぎるとconv2dできないので全部使う
+                end = x.shape[2]
+            sliced.append(x[:, :, size * i - 1 : end, :])
+            if end >= x.shape[2]:
+                break
+    return sliced
+
+
+def cat_h(sliced):
+    # padding分を除いて結合する
+    cat = []
+    for i, x in enumerate(sliced):
+        if i == 0:
+            cat.append(x[:, :, :-1, :])
+        elif i == len(sliced) - 1:
+            cat.append(x[:, :, 1:, :])
+        else:
+            cat.append(x[:, :, 1:-1, :])
+        del x
+    x = torch.cat(cat, dim=2)
+    return x
+
+
+def resblock_forward(_self, num_slices, input_tensor, temb):
+    assert _self.upsample is None and _self.downsample is None
+    assert _self.norm1.num_groups == _self.norm2.num_groups
+    assert temb is None
+
+    # make sure norms are on cpu
+    org_device = input_tensor.device
+    cpu_device = torch.device("cpu")
+    _self.norm1.to(cpu_device)
+    _self.norm2.to(cpu_device)
+
+    # すべてのテンソルをCPUに移動する
+    input_tensor = input_tensor.to(cpu_device)
+    hidden_states = input_tensor
+
+    # どうもこれは結果が異なるようだ……
+    # def sliced_norm1(norm, x):
+    #     num_div = 4 if up_block_idx <= 2 else x.shape[1] // norm.num_groups
+    #     sliced_tensor = torch.chunk(x, num_div, dim=1)
+    #     sliced_weight = torch.chunk(norm.weight, num_div, dim=0)
+    #     sliced_bias = torch.chunk(norm.bias, num_div, dim=0)
+    #     print(sliced_tensor[0].shape, num_div, sliced_weight[0].shape, sliced_bias[0].shape)
+    #     normed_tensor = []
+    #     for i in range(num_div):
+    #         n = torch.group_norm(sliced_tensor[i], norm.num_groups, sliced_weight[i], sliced_bias[i], norm.eps)
+    #         normed_tensor.append(n)
+    #         del n
+    #     x = torch.cat(normed_tensor, dim=1)
+    #     return num_div, x
+
+    # normを分割すると結果が変わるので、ここだけは分割しない。GPUで計算するとVRAMが足りなくなるので、CPUで計算する。幸いCPUでもそこまで遅くない
+    hidden_states = _self.norm1(hidden_states)  # run on cpu
+
+    sliced = slice_h(hidden_states, num_slices)
+    del hidden_states
+
+    for i in range(len(sliced)):
+        x = sliced[i]
+        sliced[i] = None
+
+        # 計算する部分だけGPUに移動する、以下同様
+        x = x.to(org_device)
+        x = _self.nonlinearity(x)
+        x = _self.conv1(x)
+        x = x.to(cpu_device)
+        sliced[i] = x
+        del x
+
+    hidden_states = cat_h(sliced)
+    del sliced
+
+    hidden_states = _self.norm2(hidden_states)  # run on cpu
+
+    sliced = slice_h(hidden_states, num_slices)
+    del hidden_states
+
+    for i in range(len(sliced)):
+        x = sliced[i]
+        sliced[i] = None
+
+        x = x.to(org_device)
+        x = _self.nonlinearity(x)
+        x = _self.dropout(x)
+        x = _self.conv2(x)
+        x = x.to(cpu_device)
+        sliced[i] = x
+        del x
+
+    hidden_states = cat_h(sliced)
+    del sliced
+
+    # make shortcut
+    if _self.conv_shortcut is not None:
+        sliced = list(torch.chunk(input_tensor, num_slices, dim=2))  # no padding in conv_shortcut パディングがないので普通にスライスする
+        del input_tensor
+
+        for i in range(len(sliced)):
+            x = sliced[i]
+            sliced[i] = None
+
+            x = x.to(org_device)
+            x = _self.conv_shortcut(x)
+            x = x.to(cpu_device)
+            sliced[i] = x
+            del x
+
+        input_tensor = torch.cat(sliced, dim=2)
+        del sliced
+
+    output_tensor = (input_tensor + hidden_states) / _self.output_scale_factor
+
+    output_tensor = output_tensor.to(org_device)  # 次のレイヤーがGPUで計算する
+    return output_tensor
+
+
+class SlicingEncoder(nn.Module):
+    def __init__(
+        self,
+        in_channels=3,
+        out_channels=3,
+        down_block_types=("DownEncoderBlock2D",),
+        block_out_channels=(64,),
+        layers_per_block=2,
+        norm_num_groups=32,
+        act_fn="silu",
+        double_z=True,
+        num_slices=2,
+    ):
+        super().__init__()
+        self.layers_per_block = layers_per_block
+
+        self.conv_in = torch.nn.Conv2d(in_channels, block_out_channels[0], kernel_size=3, stride=1, padding=1)
+
+        self.mid_block = None
+        self.down_blocks = nn.ModuleList([])
+
+        # down
+        output_channel = block_out_channels[0]
+        for i, down_block_type in enumerate(down_block_types):
+            input_channel = output_channel
+            output_channel = block_out_channels[i]
+            is_final_block = i == len(block_out_channels) - 1
+
+            down_block = get_down_block(
+                down_block_type,
+                num_layers=self.layers_per_block,
+                in_channels=input_channel,
+                out_channels=output_channel,
+                add_downsample=not is_final_block,
+                resnet_eps=1e-6,
+                downsample_padding=0,
+                resnet_act_fn=act_fn,
+                resnet_groups=norm_num_groups,
+                attn_num_head_channels=None,
+                temb_channels=None,
+            )
+            self.down_blocks.append(down_block)
+
+        # mid
+        self.mid_block = UNetMidBlock2D(
+            in_channels=block_out_channels[-1],
+            resnet_eps=1e-6,
+            resnet_act_fn=act_fn,
+            output_scale_factor=1,
+            resnet_time_scale_shift="default",
+            attn_num_head_channels=None,
+            resnet_groups=norm_num_groups,
+            temb_channels=None,
+        )
+        self.mid_block.attentions[0].set_use_memory_efficient_attention_xformers(True)  # とりあえずDiffusersのxformersを使う
+
+        # out
+        self.conv_norm_out = nn.GroupNorm(num_channels=block_out_channels[-1], num_groups=norm_num_groups, eps=1e-6)
+        self.conv_act = nn.SiLU()
+
+        conv_out_channels = 2 * out_channels if double_z else out_channels
+        self.conv_out = nn.Conv2d(block_out_channels[-1], conv_out_channels, 3, padding=1)
+
+        # replace forward of ResBlocks
+        def wrapper(func, module, num_slices):
+            def forward(*args, **kwargs):
+                return func(module, num_slices, *args, **kwargs)
+
+            return forward
+
+        self.num_slices = num_slices
+        div = num_slices / (2 ** (len(self.down_blocks) - 1))  # 深い層はそこまで分割しなくていいので適宜減らす
+        # print(f"initial divisor: {div}")
+        if div >= 2:
+            div = int(div)
+            for resnet in self.mid_block.resnets:
+                resnet.forward = wrapper(resblock_forward, resnet, div)
+            # midblock doesn't have downsample
+
+        for i, down_block in enumerate(self.down_blocks[::-1]):
+            if div >= 2:
+                div = int(div)
+                # print(f"down block: {i} divisor: {div}")
+                for resnet in down_block.resnets:
+                    resnet.forward = wrapper(resblock_forward, resnet, div)
+                if down_block.downsamplers is not None:
+                    # print("has downsample")
+                    for downsample in down_block.downsamplers:
+                        downsample.forward = wrapper(self.downsample_forward, downsample, div * 2)
+            div *= 2
+
+    def forward(self, x):
+        sample = x
+        del x
+
+        org_device = sample.device
+        cpu_device = torch.device("cpu")
+
+        # sample = self.conv_in(sample)
+        sample = sample.to(cpu_device)
+        sliced = slice_h(sample, self.num_slices)
+        del sample
+
+        for i in range(len(sliced)):
+            x = sliced[i]
+            sliced[i] = None
+
+            x = x.to(org_device)
+            x = self.conv_in(x)
+            x = x.to(cpu_device)
+            sliced[i] = x
+            del x
+
+        sample = cat_h(sliced)
+        del sliced
+
+        sample = sample.to(org_device)
+
+        # down
+        for down_block in self.down_blocks:
+            sample = down_block(sample)
+
+        # middle
+        sample = self.mid_block(sample)
+
+        # post-process
+        # ここも省メモリ化したいが、恐らくそこまでメモリを食わないので省略
+        sample = self.conv_norm_out(sample)
+        sample = self.conv_act(sample)
+        sample = self.conv_out(sample)
+
+        return sample
+
+    def downsample_forward(self, _self, num_slices, hidden_states):
+        assert hidden_states.shape[1] == _self.channels
+        assert _self.use_conv and _self.padding == 0
+        print("downsample forward", num_slices, hidden_states.shape)
+
+        org_device = hidden_states.device
+        cpu_device = torch.device("cpu")
+
+        hidden_states = hidden_states.to(cpu_device)
+        pad = (0, 1, 0, 1)
+        hidden_states = torch.nn.functional.pad(hidden_states, pad, mode="constant", value=0)
+
+        # slice with even number because of stride 2
+        # strideが2なので偶数でスライスする
+        # slice with pad 1 both sides: to eliminate side effect of padding of conv2d
+        size = (hidden_states.shape[2] + num_slices - 1) // num_slices
+        size = size + 1 if size % 2 == 1 else size
+
+        sliced = []
+        for i in range(num_slices):
+            if i == 0:
+                sliced.append(hidden_states[:, :, : size + 1, :])
+            else:
+                end = size * (i + 1) + 1
+                if hidden_states.shape[2] - end < 4:  # if the last slice is too small, use the rest of the tensor
+                    end = hidden_states.shape[2]
+                sliced.append(hidden_states[:, :, size * i - 1 : end, :])
+                if end >= hidden_states.shape[2]:
+                    break
+        del hidden_states
+
+        for i in range(len(sliced)):
+            x = sliced[i]
+            sliced[i] = None
+
+            x = x.to(org_device)
+            x = _self.conv(x)
+            x = x.to(cpu_device)
+
+            # ここだけ雰囲気が違うのはCopilotのせい
+            if i == 0:
+                hidden_states = x
+            else:
+                hidden_states = torch.cat([hidden_states, x], dim=2)
+
+        hidden_states = hidden_states.to(org_device)
+        # print("downsample forward done", hidden_states.shape)
+        return hidden_states
+
+
+class SlicingDecoder(nn.Module):
+    def __init__(
+        self,
+        in_channels=3,
+        out_channels=3,
+        up_block_types=("UpDecoderBlock2D",),
+        block_out_channels=(64,),
+        layers_per_block=2,
+        norm_num_groups=32,
+        act_fn="silu",
+        num_slices=2,
+    ):
+        super().__init__()
+        self.layers_per_block = layers_per_block
+
+        self.conv_in = nn.Conv2d(in_channels, block_out_channels[-1], kernel_size=3, stride=1, padding=1)
+
+        self.mid_block = None
+        self.up_blocks = nn.ModuleList([])
+
+        # mid
+        self.mid_block = UNetMidBlock2D(
+            in_channels=block_out_channels[-1],
+            resnet_eps=1e-6,
+            resnet_act_fn=act_fn,
+            output_scale_factor=1,
+            resnet_time_scale_shift="default",
+            attn_num_head_channels=None,
+            resnet_groups=norm_num_groups,
+            temb_channels=None,
+        )
+        self.mid_block.attentions[0].set_use_memory_efficient_attention_xformers(True)  # とりあえずDiffusersのxformersを使う
+
+        # up
+        reversed_block_out_channels = list(reversed(block_out_channels))
+        output_channel = reversed_block_out_channels[0]
+        for i, up_block_type in enumerate(up_block_types):
+            prev_output_channel = output_channel
+            output_channel = reversed_block_out_channels[i]
+
+            is_final_block = i == len(block_out_channels) - 1
+
+            up_block = get_up_block(
+                up_block_type,
+                num_layers=self.layers_per_block + 1,
+                in_channels=prev_output_channel,
+                out_channels=output_channel,
+                prev_output_channel=None,
+                add_upsample=not is_final_block,
+                resnet_eps=1e-6,
+                resnet_act_fn=act_fn,
+                resnet_groups=norm_num_groups,
+                attn_num_head_channels=None,
+                temb_channels=None,
+            )
+            self.up_blocks.append(up_block)
+            prev_output_channel = output_channel
+
+        # out
+        self.conv_norm_out = nn.GroupNorm(num_channels=block_out_channels[0], num_groups=norm_num_groups, eps=1e-6)
+        self.conv_act = nn.SiLU()
+        self.conv_out = nn.Conv2d(block_out_channels[0], out_channels, 3, padding=1)
+
+        # replace forward of ResBlocks
+        def wrapper(func, module, num_slices):
+            def forward(*args, **kwargs):
+                return func(module, num_slices, *args, **kwargs)
+
+            return forward
+
+        self.num_slices = num_slices
+        div = num_slices / (2 ** (len(self.up_blocks) - 1))
+        print(f"initial divisor: {div}")
+        if div >= 2:
+            div = int(div)
+            for resnet in self.mid_block.resnets:
+                resnet.forward = wrapper(resblock_forward, resnet, div)
+            # midblock doesn't have upsample
+
+        for i, up_block in enumerate(self.up_blocks):
+            if div >= 2:
+                div = int(div)
+                # print(f"up block: {i} divisor: {div}")
+                for resnet in up_block.resnets:
+                    resnet.forward = wrapper(resblock_forward, resnet, div)
+                if up_block.upsamplers is not None:
+                    # print("has upsample")
+                    for upsample in up_block.upsamplers:
+                        upsample.forward = wrapper(self.upsample_forward, upsample, div * 2)
+            div *= 2
+
+    def forward(self, z):
+        sample = z
+        del z
+        sample = self.conv_in(sample)
+
+        # middle
+        sample = self.mid_block(sample)
+
+        # up
+        for i, up_block in enumerate(self.up_blocks):
+            sample = up_block(sample)
+
+        # post-process
+        sample = self.conv_norm_out(sample)
+        sample = self.conv_act(sample)
+
+        # conv_out with slicing because of VRAM usage
+        # conv_outはとてもVRAM使うのでスライスして対応
+        org_device = sample.device
+        cpu_device = torch.device("cpu")
+        sample = sample.to(cpu_device)
+
+        sliced = slice_h(sample, self.num_slices)
+        del sample
+        for i in range(self.num_slices):
+            x = sliced[i]
+            sliced[i] = None
+
+            x = x.to(org_device)
+            x = self.conv_out(x)
+            x = x.to(cpu_device)
+            sliced[i] = x
+        sample = cat_h(sliced)
+        del sliced
+
+        sample = sample.to(org_device)
+        return sample
+
+    def upsample_forward(self, _self, num_slices, hidden_states, output_size=None):
+        assert hidden_states.shape[1] == _self.channels
+        assert _self.use_conv_transpose == False and _self.use_conv
+
+        org_dtype = hidden_states.dtype
+        org_device = hidden_states.device
+        cpu_device = torch.device("cpu")
+
+        hidden_states = hidden_states.to(cpu_device)
+        sliced = slice_h(hidden_states, num_slices)
+        del hidden_states
+
+        for i in range(num_slices):
+            x = sliced[i]
+            sliced[i] = None
+
+            x = x.to(org_device)
+
+            # Cast to float32 to as 'upsample_nearest2d_out_frame' op does not support bfloat16
+            # TODO(Suraj): Remove this cast once the issue is fixed in PyTorch
+            # https://github.com/pytorch/pytorch/issues/86679
+            # PyTorch 2で直らないかね……
+            if org_dtype == torch.bfloat16:
+                x = x.to(torch.float32)
+
+            x = torch.nn.functional.interpolate(x, scale_factor=2.0, mode="nearest")
+
+            if org_dtype == torch.bfloat16:
+                x = x.to(org_dtype)
+
+            x = _self.conv(x)
+
+            # upsampleされてるのでpadは2になる
+            if i == 0:
+                x = x[:, :, :-2, :]
+            elif i == num_slices - 1:
+                x = x[:, :, 2:, :]
+            else:
+                x = x[:, :, 2:-2, :]
+
+            x = x.to(cpu_device)
+            sliced[i] = x
+            del x
+
+        hidden_states = torch.cat(sliced, dim=2)
+        # print("us hidden_states", hidden_states.shape)
+        del sliced
+
+        hidden_states = hidden_states.to(org_device)
+        return hidden_states
+
+
+class SlicingAutoencoderKL(ModelMixin, ConfigMixin):
+    r"""Variational Autoencoder (VAE) model with KL loss from the paper Auto-Encoding Variational Bayes by Diederik P. Kingma
+    and Max Welling.
+
+    This model inherits from [`ModelMixin`]. Check the superclass documentation for the generic methods the library
+    implements for all the model (such as downloading or saving, etc.)
+
+    Parameters:
+        in_channels (int, *optional*, defaults to 3): Number of channels in the input image.
+        out_channels (int,  *optional*, defaults to 3): Number of channels in the output.
+        down_block_types (`Tuple[str]`, *optional*, defaults to :
+            obj:`("DownEncoderBlock2D",)`): Tuple of downsample block types.
+        up_block_types (`Tuple[str]`, *optional*, defaults to :
+            obj:`("UpDecoderBlock2D",)`): Tuple of upsample block types.
+        block_out_channels (`Tuple[int]`, *optional*, defaults to :
+            obj:`(64,)`): Tuple of block output channels.
+        act_fn (`str`, *optional*, defaults to `"silu"`): The activation function to use.
+        latent_channels (`int`, *optional*, defaults to `4`): Number of channels in the latent space.
+        sample_size (`int`, *optional*, defaults to `32`): TODO
+    """
+
+    @register_to_config
+    def __init__(
+        self,
+        in_channels: int = 3,
+        out_channels: int = 3,
+        down_block_types: Tuple[str] = ("DownEncoderBlock2D",),
+        up_block_types: Tuple[str] = ("UpDecoderBlock2D",),
+        block_out_channels: Tuple[int] = (64,),
+        layers_per_block: int = 1,
+        act_fn: str = "silu",
+        latent_channels: int = 4,
+        norm_num_groups: int = 32,
+        sample_size: int = 32,
+        num_slices: int = 16,
+    ):
+        super().__init__()
+
+        # pass init params to Encoder
+        self.encoder = SlicingEncoder(
+            in_channels=in_channels,
+            out_channels=latent_channels,
+            down_block_types=down_block_types,
+            block_out_channels=block_out_channels,
+            layers_per_block=layers_per_block,
+            act_fn=act_fn,
+            norm_num_groups=norm_num_groups,
+            double_z=True,
+            num_slices=num_slices,
+        )
+
+        # pass init params to Decoder
+        self.decoder = SlicingDecoder(
+            in_channels=latent_channels,
+            out_channels=out_channels,
+            up_block_types=up_block_types,
+            block_out_channels=block_out_channels,
+            layers_per_block=layers_per_block,
+            norm_num_groups=norm_num_groups,
+            act_fn=act_fn,
+            num_slices=num_slices,
+        )
+
+        self.quant_conv = torch.nn.Conv2d(2 * latent_channels, 2 * latent_channels, 1)
+        self.post_quant_conv = torch.nn.Conv2d(latent_channels, latent_channels, 1)
+        self.use_slicing = False
+
+    def encode(self, x: torch.FloatTensor, return_dict: bool = True) -> AutoencoderKLOutput:
+        h = self.encoder(x)
+        moments = self.quant_conv(h)
+        posterior = DiagonalGaussianDistribution(moments)
+
+        if not return_dict:
+            return (posterior,)
+
+        return AutoencoderKLOutput(latent_dist=posterior)
+
+    def _decode(self, z: torch.FloatTensor, return_dict: bool = True) -> Union[DecoderOutput, torch.FloatTensor]:
+        z = self.post_quant_conv(z)
+        dec = self.decoder(z)
+
+        if not return_dict:
+            return (dec,)
+
+        return DecoderOutput(sample=dec)
+
+    # これはバッチ方向のスライシング　紛らわしい
+    def enable_slicing(self):
+        r"""
+        Enable sliced VAE decoding.
+
+        When this option is enabled, the VAE will split the input tensor in slices to compute decoding in several
+        steps. This is useful to save some memory and allow larger batch sizes.
+        """
+        self.use_slicing = True
+
+    def disable_slicing(self):
+        r"""
+        Disable sliced VAE decoding. If `enable_slicing` was previously invoked, this method will go back to computing
+        decoding in one step.
+        """
+        self.use_slicing = False
+
+    def decode(self, z: torch.FloatTensor, return_dict: bool = True) -> Union[DecoderOutput, torch.FloatTensor]:
+        if self.use_slicing and z.shape[0] > 1:
+            decoded_slices = [self._decode(z_slice).sample for z_slice in z.split(1)]
+            decoded = torch.cat(decoded_slices)
+        else:
+            decoded = self._decode(z).sample
+
+        if not return_dict:
+            return (decoded,)
+
+        return DecoderOutput(sample=decoded)
+
+    def forward(
+        self,
+        sample: torch.FloatTensor,
+        sample_posterior: bool = False,
+        return_dict: bool = True,
+        generator: Optional[torch.Generator] = None,
+    ) -> Union[DecoderOutput, torch.FloatTensor]:
+        r"""
+        Args:
+            sample (`torch.FloatTensor`): Input sample.
+            sample_posterior (`bool`, *optional*, defaults to `False`):
+                Whether to sample from the posterior.
+            return_dict (`bool`, *optional*, defaults to `True`):
+                Whether or not to return a [`DecoderOutput`] instead of a plain tuple.
+        """
+        x = sample
+        posterior = self.encode(x).latent_dist
+        if sample_posterior:
+            z = posterior.sample(generator=generator)
+        else:
+            z = posterior.mode()
+        dec = self.decode(z).sample
+
+        if not return_dict:
+            return (dec,)
+
+        return DecoderOutput(sample=dec)