move the VAE models in src/models

move the VAE models in src/models

src/diffusers/__init__.py

@@ -7,7 +7,7 @@ from .utils import is_inflect_available, is_transformers_available, is_unidecode
 __version__ = "0.0.4"
 
 from .modeling_utils import ModelMixin
-from .models import NCSNpp, TemporalUNet, UNetLDMModel, UNetModel
+from .models import AutoencoderKL, NCSNpp, TemporalUNet, UNetLDMModel, UNetModel, VQModel
 from .pipeline_utils import DiffusionPipeline
 from .pipelines import (
     BDDMPipeline,

src/diffusers/models/__init__.py

@@ -22,3 +22,4 @@ from .unet_grad_tts import UNetGradTTSModel
 from .unet_ldm import UNetLDMModel
 from .unet_rl import TemporalUNet
 from .unet_sde_score_estimation import NCSNpp
+from .vae import AutoencoderKL, VQModel

src/diffusers/models/vae.py

+import math
+
+import numpy as np
+import torch
+import torch.nn as nn
+
+from ..configuration_utils import ConfigMixin
+from ..modeling_utils import ModelMixin
+from .attention import AttentionBlock
+from .resnet import Downsample, Upsample
+
+
+def get_timestep_embedding(timesteps, embedding_dim):
+    """
+    This matches the implementation in Denoising Diffusion Probabilistic Models: From Fairseq. Build sinusoidal
+    embeddings. This matches the implementation in tensor2tensor, but differs slightly from the description in Section
+    3.5 of "Attention Is All You Need".
+    """
+    assert len(timesteps.shape) == 1
+
+    half_dim = embedding_dim // 2
+    emb = math.log(10000) / (half_dim - 1)
+    emb = torch.exp(torch.arange(half_dim, dtype=torch.float32) * -emb)
+    emb = emb.to(device=timesteps.device)
+    emb = timesteps.float()[:, None] * emb[None, :]
+    emb = torch.cat([torch.sin(emb), torch.cos(emb)], dim=1)
+    if embedding_dim % 2 == 1:  # zero pad
+        emb = torch.nn.functional.pad(emb, (0, 1, 0, 0))
+    return emb
+
+
+def nonlinearity(x):
+    # swish
+    return x * torch.sigmoid(x)
+
+
+def Normalize(in_channels):
+    return torch.nn.GroupNorm(num_groups=32, num_channels=in_channels, eps=1e-6, affine=True)
+
+
+class ResnetBlock(nn.Module):
+    def __init__(self, *, in_channels, out_channels=None, conv_shortcut=False, dropout, temb_channels=512):
+        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.use_conv_shortcut = conv_shortcut
+
+        self.norm1 = Normalize(in_channels)
+        self.conv1 = torch.nn.Conv2d(in_channels, out_channels, kernel_size=3, stride=1, padding=1)
+        if temb_channels > 0:
+            self.temb_proj = torch.nn.Linear(temb_channels, out_channels)
+        self.norm2 = Normalize(out_channels)
+        self.dropout = torch.nn.Dropout(dropout)
+        self.conv2 = torch.nn.Conv2d(out_channels, out_channels, kernel_size=3, stride=1, padding=1)
+        if self.in_channels != self.out_channels:
+            if self.use_conv_shortcut:
+                self.conv_shortcut = torch.nn.Conv2d(in_channels, out_channels, kernel_size=3, stride=1, padding=1)
+            else:
+                self.nin_shortcut = torch.nn.Conv2d(in_channels, out_channels, kernel_size=1, stride=1, padding=0)
+
+    def forward(self, x, temb):
+        h = x
+        h = self.norm1(h)
+        h = nonlinearity(h)
+        h = self.conv1(h)
+
+        if temb is not None:
+            h = h + self.temb_proj(nonlinearity(temb))[:, :, None, None]
+
+        h = self.norm2(h)
+        h = nonlinearity(h)
+        h = self.dropout(h)
+        h = self.conv2(h)
+
+        if self.in_channels != self.out_channels:
+            if self.use_conv_shortcut:
+                x = self.conv_shortcut(x)
+            else:
+                x = self.nin_shortcut(x)
+
+        return x + h
+
+
+class Encoder(nn.Module):
+    def __init__(
+        self,
+        *,
+        ch,
+        ch_mult=(1, 2, 4, 8),
+        num_res_blocks,
+        attn_resolutions,
+        dropout=0.0,
+        resamp_with_conv=True,
+        in_channels,
+        resolution,
+        z_channels,
+        double_z=True,
+        **ignore_kwargs,
+    ):
+        super().__init__()
+        self.ch = ch
+        self.temb_ch = 0
+        self.num_resolutions = len(ch_mult)
+        self.num_res_blocks = num_res_blocks
+        self.resolution = resolution
+        self.in_channels = in_channels
+
+        # downsampling
+        self.conv_in = torch.nn.Conv2d(in_channels, self.ch, kernel_size=3, stride=1, padding=1)
+
+        curr_res = resolution
+        in_ch_mult = (1,) + tuple(ch_mult)
+        self.down = nn.ModuleList()
+        for i_level in range(self.num_resolutions):
+            block = nn.ModuleList()
+            attn = nn.ModuleList()
+            block_in = ch * in_ch_mult[i_level]
+            block_out = ch * ch_mult[i_level]
+            for i_block in range(self.num_res_blocks):
+                block.append(
+                    ResnetBlock(
+                        in_channels=block_in, out_channels=block_out, temb_channels=self.temb_ch, dropout=dropout
+                    )
+                )
+                block_in = block_out
+                if curr_res in attn_resolutions:
+                    attn.append(AttentionBlock(block_in, overwrite_qkv=True))
+            down = nn.Module()
+            down.block = block
+            down.attn = attn
+            if i_level != self.num_resolutions - 1:
+                down.downsample = Downsample(block_in, use_conv=resamp_with_conv, padding=0)
+                curr_res = curr_res // 2
+            self.down.append(down)
+
+        # middle
+        self.mid = nn.Module()
+        self.mid.block_1 = ResnetBlock(
+            in_channels=block_in, out_channels=block_in, temb_channels=self.temb_ch, dropout=dropout
+        )
+        self.mid.attn_1 = AttentionBlock(block_in, overwrite_qkv=True)
+        self.mid.block_2 = ResnetBlock(
+            in_channels=block_in, out_channels=block_in, temb_channels=self.temb_ch, dropout=dropout
+        )
+
+        # end
+        self.norm_out = Normalize(block_in)
+        self.conv_out = torch.nn.Conv2d(
+            block_in, 2 * z_channels if double_z else z_channels, kernel_size=3, stride=1, padding=1
+        )
+
+    def forward(self, x):
+        # assert x.shape[2] == x.shape[3] == self.resolution, "{}, {}, {}".format(x.shape[2], x.shape[3], self.resolution)
+
+        # timestep embedding
+        temb = None
+
+        # downsampling
+        hs = [self.conv_in(x)]
+        for i_level in range(self.num_resolutions):
+            for i_block in range(self.num_res_blocks):
+                h = self.down[i_level].block[i_block](hs[-1], temb)
+                if len(self.down[i_level].attn) > 0:
+                    h = self.down[i_level].attn[i_block](h)
+                hs.append(h)
+            if i_level != self.num_resolutions - 1:
+                hs.append(self.down[i_level].downsample(hs[-1]))
+
+        # middle
+        h = hs[-1]
+        h = self.mid.block_1(h, temb)
+        h = self.mid.attn_1(h)
+        h = self.mid.block_2(h, temb)
+
+        # end
+        h = self.norm_out(h)
+        h = nonlinearity(h)
+        h = self.conv_out(h)
+        return h
+
+
+class Decoder(nn.Module):
+    def __init__(
+        self,
+        *,
+        ch,
+        out_ch,
+        ch_mult=(1, 2, 4, 8),
+        num_res_blocks,
+        attn_resolutions,
+        dropout=0.0,
+        resamp_with_conv=True,
+        in_channels,
+        resolution,
+        z_channels,
+        give_pre_end=False,
+        **ignorekwargs,
+    ):
+        super().__init__()
+        self.ch = ch
+        self.temb_ch = 0
+        self.num_resolutions = len(ch_mult)
+        self.num_res_blocks = num_res_blocks
+        self.resolution = resolution
+        self.in_channels = in_channels
+        self.give_pre_end = give_pre_end
+
+        # compute in_ch_mult, block_in and curr_res at lowest res
+        block_in = ch * ch_mult[self.num_resolutions - 1]
+        curr_res = resolution // 2 ** (self.num_resolutions - 1)
+        self.z_shape = (1, z_channels, curr_res, curr_res)
+        print("Working with z of shape {} = {} dimensions.".format(self.z_shape, np.prod(self.z_shape)))
+
+        # z to block_in
+        self.conv_in = torch.nn.Conv2d(z_channels, block_in, kernel_size=3, stride=1, padding=1)
+
+        # middle
+        self.mid = nn.Module()
+        self.mid.block_1 = ResnetBlock(
+            in_channels=block_in, out_channels=block_in, temb_channels=self.temb_ch, dropout=dropout
+        )
+        self.mid.attn_1 = AttentionBlock(block_in, overwrite_qkv=True)
+        self.mid.block_2 = ResnetBlock(
+            in_channels=block_in, out_channels=block_in, temb_channels=self.temb_ch, dropout=dropout
+        )
+
+        # upsampling
+        self.up = nn.ModuleList()
+        for i_level in reversed(range(self.num_resolutions)):
+            block = nn.ModuleList()
+            attn = nn.ModuleList()
+            block_out = ch * ch_mult[i_level]
+            for i_block in range(self.num_res_blocks + 1):
+                block.append(
+                    ResnetBlock(
+                        in_channels=block_in, out_channels=block_out, temb_channels=self.temb_ch, dropout=dropout
+                    )
+                )
+                block_in = block_out
+                if curr_res in attn_resolutions:
+                    attn.append(AttentionBlock(block_in, overwrite_qkv=True))
+            up = nn.Module()
+            up.block = block
+            up.attn = attn
+            if i_level != 0:
+                up.upsample = Upsample(block_in, use_conv=resamp_with_conv)
+                curr_res = curr_res * 2
+            self.up.insert(0, up)  # prepend to get consistent order
+
+        # end
+        self.norm_out = Normalize(block_in)
+        self.conv_out = torch.nn.Conv2d(block_in, out_ch, kernel_size=3, stride=1, padding=1)
+
+    def forward(self, z):
+        # assert z.shape[1:] == self.z_shape[1:]
+        self.last_z_shape = z.shape
+
+        # timestep embedding
+        temb = None
+
+        # z to block_in
+        h = self.conv_in(z)
+
+        # middle
+        h = self.mid.block_1(h, temb)
+        h = self.mid.attn_1(h)
+        h = self.mid.block_2(h, temb)
+
+        # upsampling
+        for i_level in reversed(range(self.num_resolutions)):
+            for i_block in range(self.num_res_blocks + 1):
+                h = self.up[i_level].block[i_block](h, temb)
+                if len(self.up[i_level].attn) > 0:
+                    h = self.up[i_level].attn[i_block](h)
+            if i_level != 0:
+                h = self.up[i_level].upsample(h)
+
+        # end
+        if self.give_pre_end:
+            return h
+
+        h = self.norm_out(h)
+        h = nonlinearity(h)
+        h = self.conv_out(h)
+        return h
+
+
+class VectorQuantizer(nn.Module):
+    """
+    Improved version over VectorQuantizer, can be used as a drop-in replacement. Mostly avoids costly matrix
+    multiplications and allows for post-hoc remapping of indices.
+    """
+
+    # NOTE: due to a bug the beta term was applied to the wrong term. for
+    # backwards compatibility we use the buggy version by default, but you can
+    # specify legacy=False to fix it.
+    def __init__(self, n_e, e_dim, beta, remap=None, unknown_index="random", sane_index_shape=False, legacy=True):
+        super().__init__()
+        self.n_e = n_e
+        self.e_dim = e_dim
+        self.beta = beta
+        self.legacy = legacy
+
+        self.embedding = nn.Embedding(self.n_e, self.e_dim)
+        self.embedding.weight.data.uniform_(-1.0 / self.n_e, 1.0 / self.n_e)
+
+        self.remap = remap
+        if self.remap is not None:
+            self.register_buffer("used", torch.tensor(np.load(self.remap)))
+            self.re_embed = self.used.shape[0]
+            self.unknown_index = unknown_index  # "random" or "extra" or integer
+            if self.unknown_index == "extra":
+                self.unknown_index = self.re_embed
+                self.re_embed = self.re_embed + 1
+            print(
+                f"Remapping {self.n_e} indices to {self.re_embed} indices. "
+                f"Using {self.unknown_index} for unknown indices."
+            )
+        else:
+            self.re_embed = n_e
+
+        self.sane_index_shape = sane_index_shape
+
+    def remap_to_used(self, inds):
+        ishape = inds.shape
+        assert len(ishape) > 1
+        inds = inds.reshape(ishape[0], -1)
+        used = self.used.to(inds)
+        match = (inds[:, :, None] == used[None, None, ...]).long()
+        new = match.argmax(-1)
+        unknown = match.sum(2) < 1
+        if self.unknown_index == "random":
+            new[unknown] = torch.randint(0, self.re_embed, size=new[unknown].shape).to(device=new.device)
+        else:
+            new[unknown] = self.unknown_index
+        return new.reshape(ishape)
+
+    def unmap_to_all(self, inds):
+        ishape = inds.shape
+        assert len(ishape) > 1
+        inds = inds.reshape(ishape[0], -1)
+        used = self.used.to(inds)
+        if self.re_embed > self.used.shape[0]:  # extra token
+            inds[inds >= self.used.shape[0]] = 0  # simply set to zero
+        back = torch.gather(used[None, :][inds.shape[0] * [0], :], 1, inds)
+        return back.reshape(ishape)
+
+    def forward(self, z):
+        # reshape z -> (batch, height, width, channel) and flatten
+        z = z.permute(0, 2, 3, 1).contiguous()
+        z_flattened = z.view(-1, self.e_dim)
+        # distances from z to embeddings e_j (z - e)^2 = z^2 + e^2 - 2 e * z
+
+        d = (
+            torch.sum(z_flattened**2, dim=1, keepdim=True)
+            + torch.sum(self.embedding.weight**2, dim=1)
+            - 2 * torch.einsum("bd,dn->bn", z_flattened, self.embedding.weight.t())
+        )
+
+        min_encoding_indices = torch.argmin(d, dim=1)
+        z_q = self.embedding(min_encoding_indices).view(z.shape)
+        perplexity = None
+        min_encodings = None
+
+        # compute loss for embedding
+        if not self.legacy:
+            loss = self.beta * torch.mean((z_q.detach() - z) ** 2) + torch.mean((z_q - z.detach()) ** 2)
+        else:
+            loss = torch.mean((z_q.detach() - z) ** 2) + self.beta * torch.mean((z_q - z.detach()) ** 2)
+
+        # preserve gradients
+        z_q = z + (z_q - z).detach()
+
+        # reshape back to match original input shape
+        z_q = z_q.permute(0, 3, 1, 2).contiguous()
+
+        if self.remap is not None:
+            min_encoding_indices = min_encoding_indices.reshape(z.shape[0], -1)  # add batch axis
+            min_encoding_indices = self.remap_to_used(min_encoding_indices)
+            min_encoding_indices = min_encoding_indices.reshape(-1, 1)  # flatten
+
+        if self.sane_index_shape:
+            min_encoding_indices = min_encoding_indices.reshape(z_q.shape[0], z_q.shape[2], z_q.shape[3])
+
+        return z_q, loss, (perplexity, min_encodings, min_encoding_indices)
+
+    def get_codebook_entry(self, indices, shape):
+        # shape specifying (batch, height, width, channel)
+        if self.remap is not None:
+            indices = indices.reshape(shape[0], -1)  # add batch axis
+            indices = self.unmap_to_all(indices)
+            indices = indices.reshape(-1)  # flatten again
+
+        # get quantized latent vectors
+        z_q = self.embedding(indices)
+
+        if shape is not None:
+            z_q = z_q.view(shape)
+            # reshape back to match original input shape
+            z_q = z_q.permute(0, 3, 1, 2).contiguous()
+
+        return z_q
+
+
+class DiagonalGaussianDistribution(object):
+    def __init__(self, parameters, deterministic=False):
+        self.parameters = parameters
+        self.mean, self.logvar = torch.chunk(parameters, 2, dim=1)
+        self.logvar = torch.clamp(self.logvar, -30.0, 20.0)
+        self.deterministic = deterministic
+        self.std = torch.exp(0.5 * self.logvar)
+        self.var = torch.exp(self.logvar)
+        if self.deterministic:
+            self.var = self.std = torch.zeros_like(self.mean).to(device=self.parameters.device)
+
+    def sample(self):
+        x = self.mean + self.std * torch.randn(self.mean.shape).to(device=self.parameters.device)
+        return x
+
+    def kl(self, other=None):
+        if self.deterministic:
+            return torch.Tensor([0.0])
+        else:
+            if other is None:
+                return 0.5 * torch.sum(torch.pow(self.mean, 2) + self.var - 1.0 - self.logvar, dim=[1, 2, 3])
+            else:
+                return 0.5 * torch.sum(
+                    torch.pow(self.mean - other.mean, 2) / other.var
+                    + self.var / other.var
+                    - 1.0
+                    - self.logvar
+                    + other.logvar,
+                    dim=[1, 2, 3],
+                )
+
+    def nll(self, sample, dims=[1, 2, 3]):
+        if self.deterministic:
+            return torch.Tensor([0.0])
+        logtwopi = np.log(2.0 * np.pi)
+        return 0.5 * torch.sum(logtwopi + self.logvar + torch.pow(sample - self.mean, 2) / self.var, dim=dims)
+
+    def mode(self):
+        return self.mean
+
+
+class VQModel(ModelMixin, ConfigMixin):
+    def __init__(
+        self,
+        ch,
+        out_ch,
+        num_res_blocks,
+        attn_resolutions,
+        in_channels,
+        resolution,
+        z_channels,
+        n_embed,
+        embed_dim,
+        remap=None,
+        sane_index_shape=False,  # tell vector quantizer to return indices as bhw
+        ch_mult=(1, 2, 4, 8),
+        dropout=0.0,
+        double_z=True,
+        resamp_with_conv=True,
+        give_pre_end=False,
+    ):
+        super().__init__()
+
+        # register all __init__ params with self.register
+        self.register_to_config(
+            ch=ch,
+            out_ch=out_ch,
+            num_res_blocks=num_res_blocks,
+            attn_resolutions=attn_resolutions,
+            in_channels=in_channels,
+            resolution=resolution,
+            z_channels=z_channels,
+            n_embed=n_embed,
+            embed_dim=embed_dim,
+            remap=remap,
+            sane_index_shape=sane_index_shape,
+            ch_mult=ch_mult,
+            dropout=dropout,
+            double_z=double_z,
+            resamp_with_conv=resamp_with_conv,
+            give_pre_end=give_pre_end,
+        )
+
+        # pass init params to Encoder
+        self.encoder = Encoder(
+            ch=ch,
+            num_res_blocks=num_res_blocks,
+            attn_resolutions=attn_resolutions,
+            in_channels=in_channels,
+            resolution=resolution,
+            z_channels=z_channels,
+            ch_mult=ch_mult,
+            dropout=dropout,
+            resamp_with_conv=resamp_with_conv,
+            double_z=double_z,
+            give_pre_end=give_pre_end,
+        )
+
+        self.quant_conv = torch.nn.Conv2d(z_channels, embed_dim, 1)
+        self.quantize = VectorQuantizer(n_embed, embed_dim, beta=0.25, remap=remap, sane_index_shape=sane_index_shape)
+        self.post_quant_conv = torch.nn.Conv2d(embed_dim, z_channels, 1)
+
+        # pass init params to Decoder
+        self.decoder = Decoder(
+            ch=ch,
+            out_ch=out_ch,
+            num_res_blocks=num_res_blocks,
+            attn_resolutions=attn_resolutions,
+            in_channels=in_channels,
+            resolution=resolution,
+            z_channels=z_channels,
+            ch_mult=ch_mult,
+            dropout=dropout,
+            resamp_with_conv=resamp_with_conv,
+            give_pre_end=give_pre_end,
+        )
+
+    def encode(self, x):
+        h = self.encoder(x)
+        h = self.quant_conv(h)
+        return h
+
+    def decode(self, h, force_not_quantize=False):
+        # also go through quantization layer
+        if not force_not_quantize:
+            quant, emb_loss, info = self.quantize(h)
+        else:
+            quant = h
+        quant = self.post_quant_conv(quant)
+        dec = self.decoder(quant)
+        return dec
+
+    def forward(self, x):
+        h = self.encode(x)
+        dec = self.decode(h)
+        return dec
+
+
+class AutoencoderKL(ModelMixin, ConfigMixin):
+    def __init__(
+        self,
+        ch,
+        out_ch,
+        num_res_blocks,
+        attn_resolutions,
+        in_channels,
+        resolution,
+        z_channels,
+        embed_dim,
+        remap=None,
+        sane_index_shape=False,  # tell vector quantizer to return indices as bhw
+        ch_mult=(1, 2, 4, 8),
+        dropout=0.0,
+        double_z=True,
+        resamp_with_conv=True,
+        give_pre_end=False,
+    ):
+        super().__init__()
+
+        # register all __init__ params with self.register
+        self.register_to_config(
+            ch=ch,
+            out_ch=out_ch,
+            num_res_blocks=num_res_blocks,
+            attn_resolutions=attn_resolutions,
+            in_channels=in_channels,
+            resolution=resolution,
+            z_channels=z_channels,
+            embed_dim=embed_dim,
+            remap=remap,
+            sane_index_shape=sane_index_shape,
+            ch_mult=ch_mult,
+            dropout=dropout,
+            double_z=double_z,
+            resamp_with_conv=resamp_with_conv,
+            give_pre_end=give_pre_end,
+        )
+
+        # pass init params to Encoder
+        self.encoder = Encoder(
+            ch=ch,
+            out_ch=out_ch,
+            num_res_blocks=num_res_blocks,
+            attn_resolutions=attn_resolutions,
+            in_channels=in_channels,
+            resolution=resolution,
+            z_channels=z_channels,
+            ch_mult=ch_mult,
+            dropout=dropout,
+            resamp_with_conv=resamp_with_conv,
+            double_z=double_z,
+            give_pre_end=give_pre_end,
+        )
+
+        # pass init params to Decoder
+        self.decoder = Decoder(
+            ch=ch,
+            out_ch=out_ch,
+            num_res_blocks=num_res_blocks,
+            attn_resolutions=attn_resolutions,
+            in_channels=in_channels,
+            resolution=resolution,
+            z_channels=z_channels,
+            ch_mult=ch_mult,
+            dropout=dropout,
+            resamp_with_conv=resamp_with_conv,
+            give_pre_end=give_pre_end,
+        )
+
+        self.quant_conv = torch.nn.Conv2d(2 * z_channels, 2 * embed_dim, 1)
+        self.post_quant_conv = torch.nn.Conv2d(embed_dim, z_channels, 1)
+
+    def encode(self, x):
+        h = self.encoder(x)
+        moments = self.quant_conv(h)
+        posterior = DiagonalGaussianDistribution(moments)
+        return posterior
+
+    def decode(self, z):
+        z = self.post_quant_conv(z)
+        dec = self.decoder(z)
+        return dec
+
+    def forward(self, x, sample_posterior=False):
+        posterior = self.encode(x)
+        if sample_posterior:
+            z = posterior.sample()
+        else:
+            z = posterior.mode()
+        dec = self.decode(z)
+        return dec

src/diffusers/pipelines/latent_diffusion/__init__.py

@@ -2,4 +2,4 @@ from ...utils import is_transformers_available
 
 
 if is_transformers_available():
-    from .pipeline_latent_diffusion import AutoencoderKL, LatentDiffusionPipeline, LDMBertModel
+    from .pipeline_latent_diffusion import LatentDiffusionPipeline, LDMBertModel

src/diffusers/pipelines/latent_diffusion/pipeline_latent_diffusion.py

-import math
 from typing import Optional, Tuple, Union
 
 import numpy as np
@@ -13,8 +12,6 @@ from transformers.modeling_outputs import BaseModelOutput
 from transformers.modeling_utils import PreTrainedModel
 from transformers.utils import logging
 
-from ...configuration_utils import ConfigMixin
-from ...modeling_utils import ModelMixin
 from ...pipeline_utils import DiffusionPipeline
 
 
@@ -547,852 +544,6 @@ class LDMBertModel(LDMBertPreTrainedModel):
         return sequence_output
 
 
-def get_timestep_embedding(timesteps, embedding_dim):
-    """
-    This matches the implementation in Denoising Diffusion Probabilistic Models: From Fairseq. Build sinusoidal
-    embeddings. This matches the implementation in tensor2tensor, but differs slightly from the description in Section
-    3.5 of "Attention Is All You Need".
-    """
-    assert len(timesteps.shape) == 1
-
-    half_dim = embedding_dim // 2
-    emb = math.log(10000) / (half_dim - 1)
-    emb = torch.exp(torch.arange(half_dim, dtype=torch.float32) * -emb)
-    emb = emb.to(device=timesteps.device)
-    emb = timesteps.float()[:, None] * emb[None, :]
-    emb = torch.cat([torch.sin(emb), torch.cos(emb)], dim=1)
-    if embedding_dim % 2 == 1:  # zero pad
-        emb = torch.nn.functional.pad(emb, (0, 1, 0, 0))
-    return emb
-
-
-def nonlinearity(x):
-    # swish
-    return x * torch.sigmoid(x)
-
-
-def Normalize(in_channels):
-    return torch.nn.GroupNorm(num_groups=32, num_channels=in_channels, eps=1e-6, affine=True)
-
-
-class Upsample(nn.Module):
-    def __init__(self, in_channels, with_conv):
-        super().__init__()
-        self.with_conv = with_conv
-        if self.with_conv:
-            self.conv = torch.nn.Conv2d(in_channels, in_channels, kernel_size=3, stride=1, padding=1)
-
-    def forward(self, x):
-        x = torch.nn.functional.interpolate(x, scale_factor=2.0, mode="nearest")
-        if self.with_conv:
-            x = self.conv(x)
-        return x
-
-
-class Downsample(nn.Module):
-    def __init__(self, in_channels, with_conv):
-        super().__init__()
-        self.with_conv = with_conv
-        if self.with_conv:
-            # no asymmetric padding in torch conv, must do it ourselves
-            self.conv = torch.nn.Conv2d(in_channels, in_channels, kernel_size=3, stride=2, padding=0)
-
-    def forward(self, x):
-        if self.with_conv:
-            pad = (0, 1, 0, 1)
-            x = torch.nn.functional.pad(x, pad, mode="constant", value=0)
-            x = self.conv(x)
-        else:
-            x = torch.nn.functional.avg_pool2d(x, kernel_size=2, stride=2)
-        return x
-
-
-class ResnetBlock(nn.Module):
-    def __init__(self, *, in_channels, out_channels=None, conv_shortcut=False, dropout, temb_channels=512):
-        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.use_conv_shortcut = conv_shortcut
-
-        self.norm1 = Normalize(in_channels)
-        self.conv1 = torch.nn.Conv2d(in_channels, out_channels, kernel_size=3, stride=1, padding=1)
-        if temb_channels > 0:
-            self.temb_proj = torch.nn.Linear(temb_channels, out_channels)
-        self.norm2 = Normalize(out_channels)
-        self.dropout = torch.nn.Dropout(dropout)
-        self.conv2 = torch.nn.Conv2d(out_channels, out_channels, kernel_size=3, stride=1, padding=1)
-        if self.in_channels != self.out_channels:
-            if self.use_conv_shortcut:
-                self.conv_shortcut = torch.nn.Conv2d(in_channels, out_channels, kernel_size=3, stride=1, padding=1)
-            else:
-                self.nin_shortcut = torch.nn.Conv2d(in_channels, out_channels, kernel_size=1, stride=1, padding=0)
-
-    def forward(self, x, temb):
-        h = x
-        h = self.norm1(h)
-        h = nonlinearity(h)
-        h = self.conv1(h)
-
-        if temb is not None:
-            h = h + self.temb_proj(nonlinearity(temb))[:, :, None, None]
-
-        h = self.norm2(h)
-        h = nonlinearity(h)
-        h = self.dropout(h)
-        h = self.conv2(h)
-
-        if self.in_channels != self.out_channels:
-            if self.use_conv_shortcut:
-                x = self.conv_shortcut(x)
-            else:
-                x = self.nin_shortcut(x)
-
-        return x + h
-
-
-class AttnBlock(nn.Module):
-    def __init__(self, in_channels):
-        super().__init__()
-        self.in_channels = in_channels
-
-        self.norm = Normalize(in_channels)
-        self.q = torch.nn.Conv2d(in_channels, in_channels, kernel_size=1, stride=1, padding=0)
-        self.k = torch.nn.Conv2d(in_channels, in_channels, kernel_size=1, stride=1, padding=0)
-        self.v = torch.nn.Conv2d(in_channels, in_channels, kernel_size=1, stride=1, padding=0)
-        self.proj_out = torch.nn.Conv2d(in_channels, in_channels, kernel_size=1, stride=1, padding=0)
-
-    def forward(self, x):
-        h_ = x
-        h_ = self.norm(h_)
-        q = self.q(h_)
-        k = self.k(h_)
-        v = self.v(h_)
-
-        # compute attention
-        b, c, h, w = q.shape
-        q = q.reshape(b, c, h * w)
-        q = q.permute(0, 2, 1)  # b,hw,c
-        k = k.reshape(b, c, h * w)  # b,c,hw
-        w_ = torch.bmm(q, k)  # b,hw,hw    w[b,i,j]=sum_c q[b,i,c]k[b,c,j]
-        w_ = w_ * (int(c) ** (-0.5))
-        w_ = torch.nn.functional.softmax(w_, dim=2)
-
-        # attend to values
-        v = v.reshape(b, c, h * w)
-        w_ = w_.permute(0, 2, 1)  # b,hw,hw (first hw of k, second of q)
-        h_ = torch.bmm(v, w_)  # b, c,hw (hw of q) h_[b,c,j] = sum_i v[b,c,i] w_[b,i,j]
-        h_ = h_.reshape(b, c, h, w)
-
-        h_ = self.proj_out(h_)
-
-        return x + h_
-
-
-class Model(nn.Module):
-    def __init__(
-        self,
-        *,
-        ch,
-        out_ch,
-        ch_mult=(1, 2, 4, 8),
-        num_res_blocks,
-        attn_resolutions,
-        dropout=0.0,
-        resamp_with_conv=True,
-        in_channels,
-        resolution,
-        use_timestep=True,
-    ):
-        super().__init__()
-        self.ch = ch
-        self.temb_ch = self.ch * 4
-        self.num_resolutions = len(ch_mult)
-        self.num_res_blocks = num_res_blocks
-        self.resolution = resolution
-        self.in_channels = in_channels
-
-        self.use_timestep = use_timestep
-        if self.use_timestep:
-            # timestep embedding
-            self.temb = nn.Module()
-            self.temb.dense = nn.ModuleList(
-                [
-                    torch.nn.Linear(self.ch, self.temb_ch),
-                    torch.nn.Linear(self.temb_ch, self.temb_ch),
-                ]
-            )
-
-        # downsampling
-        self.conv_in = torch.nn.Conv2d(in_channels, self.ch, kernel_size=3, stride=1, padding=1)
-
-        curr_res = resolution
-        in_ch_mult = (1,) + tuple(ch_mult)
-        self.down = nn.ModuleList()
-        for i_level in range(self.num_resolutions):
-            block = nn.ModuleList()
-            attn = nn.ModuleList()
-            block_in = ch * in_ch_mult[i_level]
-            block_out = ch * ch_mult[i_level]
-            for i_block in range(self.num_res_blocks):
-                block.append(
-                    ResnetBlock(
-                        in_channels=block_in, out_channels=block_out, temb_channels=self.temb_ch, dropout=dropout
-                    )
-                )
-                block_in = block_out
-                if curr_res in attn_resolutions:
-                    attn.append(AttnBlock(block_in))
-            down = nn.Module()
-            down.block = block
-            down.attn = attn
-            if i_level != self.num_resolutions - 1:
-                down.downsample = Downsample(block_in, resamp_with_conv)
-                curr_res = curr_res // 2
-            self.down.append(down)
-
-        # middle
-        self.mid = nn.Module()
-        self.mid.block_1 = ResnetBlock(
-            in_channels=block_in, out_channels=block_in, temb_channels=self.temb_ch, dropout=dropout
-        )
-        self.mid.attn_1 = AttnBlock(block_in)
-        self.mid.block_2 = ResnetBlock(
-            in_channels=block_in, out_channels=block_in, temb_channels=self.temb_ch, dropout=dropout
-        )
-
-        # upsampling
-        self.up = nn.ModuleList()
-        for i_level in reversed(range(self.num_resolutions)):
-            block = nn.ModuleList()
-            attn = nn.ModuleList()
-            block_out = ch * ch_mult[i_level]
-            skip_in = ch * ch_mult[i_level]
-            for i_block in range(self.num_res_blocks + 1):
-                if i_block == self.num_res_blocks:
-                    skip_in = ch * in_ch_mult[i_level]
-                block.append(
-                    ResnetBlock(
-                        in_channels=block_in + skip_in,
-                        out_channels=block_out,
-                        temb_channels=self.temb_ch,
-                        dropout=dropout,
-                    )
-                )
-                block_in = block_out
-                if curr_res in attn_resolutions:
-                    attn.append(AttnBlock(block_in))
-            up = nn.Module()
-            up.block = block
-            up.attn = attn
-            if i_level != 0:
-                up.upsample = Upsample(block_in, resamp_with_conv)
-                curr_res = curr_res * 2
-            self.up.insert(0, up)  # prepend to get consistent order
-
-        # end
-        self.norm_out = Normalize(block_in)
-        self.conv_out = torch.nn.Conv2d(block_in, out_ch, kernel_size=3, stride=1, padding=1)
-
-    def forward(self, x, t=None):
-        # assert x.shape[2] == x.shape[3] == self.resolution
-
-        if self.use_timestep:
-            # timestep embedding
-            assert t is not None
-            temb = get_timestep_embedding(t, self.ch)
-            temb = self.temb.dense[0](temb)
-            temb = nonlinearity(temb)
-            temb = self.temb.dense[1](temb)
-        else:
-            temb = None
-
-        # downsampling
-        hs = [self.conv_in(x)]
-        for i_level in range(self.num_resolutions):
-            for i_block in range(self.num_res_blocks):
-                h = self.down[i_level].block[i_block](hs[-1], temb)
-                if len(self.down[i_level].attn) > 0:
-                    h = self.down[i_level].attn[i_block](h)
-                hs.append(h)
-            if i_level != self.num_resolutions - 1:
-                hs.append(self.down[i_level].downsample(hs[-1]))
-
-        # middle
-        h = hs[-1]
-        h = self.mid.block_1(h, temb)
-        h = self.mid.attn_1(h)
-        h = self.mid.block_2(h, temb)
-
-        # upsampling
-        for i_level in reversed(range(self.num_resolutions)):
-            for i_block in range(self.num_res_blocks + 1):
-                h = self.up[i_level].block[i_block](torch.cat([h, hs.pop()], dim=1), temb)
-                if len(self.up[i_level].attn) > 0:
-                    h = self.up[i_level].attn[i_block](h)
-            if i_level != 0:
-                h = self.up[i_level].upsample(h)
-
-        # end
-        h = self.norm_out(h)
-        h = nonlinearity(h)
-        h = self.conv_out(h)
-        return h
-
-
-class Encoder(nn.Module):
-    def __init__(
-        self,
-        *,
-        ch,
-        out_ch,
-        ch_mult=(1, 2, 4, 8),
-        num_res_blocks,
-        attn_resolutions,
-        dropout=0.0,
-        resamp_with_conv=True,
-        in_channels,
-        resolution,
-        z_channels,
-        double_z=True,
-        **ignore_kwargs,
-    ):
-        super().__init__()
-        self.ch = ch
-        self.temb_ch = 0
-        self.num_resolutions = len(ch_mult)
-        self.num_res_blocks = num_res_blocks
-        self.resolution = resolution
-        self.in_channels = in_channels
-
-        # downsampling
-        self.conv_in = torch.nn.Conv2d(in_channels, self.ch, kernel_size=3, stride=1, padding=1)
-
-        curr_res = resolution
-        in_ch_mult = (1,) + tuple(ch_mult)
-        self.down = nn.ModuleList()
-        for i_level in range(self.num_resolutions):
-            block = nn.ModuleList()
-            attn = nn.ModuleList()
-            block_in = ch * in_ch_mult[i_level]
-            block_out = ch * ch_mult[i_level]
-            for i_block in range(self.num_res_blocks):
-                block.append(
-                    ResnetBlock(
-                        in_channels=block_in, out_channels=block_out, temb_channels=self.temb_ch, dropout=dropout
-                    )
-                )
-                block_in = block_out
-                if curr_res in attn_resolutions:
-                    attn.append(AttnBlock(block_in))
-            down = nn.Module()
-            down.block = block
-            down.attn = attn
-            if i_level != self.num_resolutions - 1:
-                down.downsample = Downsample(block_in, resamp_with_conv)
-                curr_res = curr_res // 2
-            self.down.append(down)
-
-        # middle
-        self.mid = nn.Module()
-        self.mid.block_1 = ResnetBlock(
-            in_channels=block_in, out_channels=block_in, temb_channels=self.temb_ch, dropout=dropout
-        )
-        self.mid.attn_1 = AttnBlock(block_in)
-        self.mid.block_2 = ResnetBlock(
-            in_channels=block_in, out_channels=block_in, temb_channels=self.temb_ch, dropout=dropout
-        )
-
-        # end
-        self.norm_out = Normalize(block_in)
-        self.conv_out = torch.nn.Conv2d(
-            block_in, 2 * z_channels if double_z else z_channels, kernel_size=3, stride=1, padding=1
-        )
-
-    def forward(self, x):
-        # assert x.shape[2] == x.shape[3] == self.resolution, "{}, {}, {}".format(x.shape[2], x.shape[3], self.resolution)
-
-        # timestep embedding
-        temb = None
-
-        # downsampling
-        hs = [self.conv_in(x)]
-        for i_level in range(self.num_resolutions):
-            for i_block in range(self.num_res_blocks):
-                h = self.down[i_level].block[i_block](hs[-1], temb)
-                if len(self.down[i_level].attn) > 0:
-                    h = self.down[i_level].attn[i_block](h)
-                hs.append(h)
-            if i_level != self.num_resolutions - 1:
-                hs.append(self.down[i_level].downsample(hs[-1]))
-
-        # middle
-        h = hs[-1]
-        h = self.mid.block_1(h, temb)
-        h = self.mid.attn_1(h)
-        h = self.mid.block_2(h, temb)
-
-        # end
-        h = self.norm_out(h)
-        h = nonlinearity(h)
-        h = self.conv_out(h)
-        return h
-
-
-class Decoder(nn.Module):
-    def __init__(
-        self,
-        *,
-        ch,
-        out_ch,
-        ch_mult=(1, 2, 4, 8),
-        num_res_blocks,
-        attn_resolutions,
-        dropout=0.0,
-        resamp_with_conv=True,
-        in_channels,
-        resolution,
-        z_channels,
-        give_pre_end=False,
-        **ignorekwargs,
-    ):
-        super().__init__()
-        self.ch = ch
-        self.temb_ch = 0
-        self.num_resolutions = len(ch_mult)
-        self.num_res_blocks = num_res_blocks
-        self.resolution = resolution
-        self.in_channels = in_channels
-        self.give_pre_end = give_pre_end
-
-        # compute in_ch_mult, block_in and curr_res at lowest res
-        in_ch_mult = (1,) + tuple(ch_mult)
-        block_in = ch * ch_mult[self.num_resolutions - 1]
-        curr_res = resolution // 2 ** (self.num_resolutions - 1)
-        self.z_shape = (1, z_channels, curr_res, curr_res)
-        print("Working with z of shape {} = {} dimensions.".format(self.z_shape, np.prod(self.z_shape)))
-
-        # z to block_in
-        self.conv_in = torch.nn.Conv2d(z_channels, block_in, kernel_size=3, stride=1, padding=1)
-
-        # middle
-        self.mid = nn.Module()
-        self.mid.block_1 = ResnetBlock(
-            in_channels=block_in, out_channels=block_in, temb_channels=self.temb_ch, dropout=dropout
-        )
-        self.mid.attn_1 = AttnBlock(block_in)
-        self.mid.block_2 = ResnetBlock(
-            in_channels=block_in, out_channels=block_in, temb_channels=self.temb_ch, dropout=dropout
-        )
-
-        # upsampling
-        self.up = nn.ModuleList()
-        for i_level in reversed(range(self.num_resolutions)):
-            block = nn.ModuleList()
-            attn = nn.ModuleList()
-            block_out = ch * ch_mult[i_level]
-            for i_block in range(self.num_res_blocks + 1):
-                block.append(
-                    ResnetBlock(
-                        in_channels=block_in, out_channels=block_out, temb_channels=self.temb_ch, dropout=dropout
-                    )
-                )
-                block_in = block_out
-                if curr_res in attn_resolutions:
-                    attn.append(AttnBlock(block_in))
-            up = nn.Module()
-            up.block = block
-            up.attn = attn
-            if i_level != 0:
-                up.upsample = Upsample(block_in, resamp_with_conv)
-                curr_res = curr_res * 2
-            self.up.insert(0, up)  # prepend to get consistent order
-
-        # end
-        self.norm_out = Normalize(block_in)
-        self.conv_out = torch.nn.Conv2d(block_in, out_ch, kernel_size=3, stride=1, padding=1)
-
-    def forward(self, z):
-        # assert z.shape[1:] == self.z_shape[1:]
-        self.last_z_shape = z.shape
-
-        # timestep embedding
-        temb = None
-
-        # z to block_in
-        h = self.conv_in(z)
-
-        # middle
-        h = self.mid.block_1(h, temb)
-        h = self.mid.attn_1(h)
-        h = self.mid.block_2(h, temb)
-
-        # upsampling
-        for i_level in reversed(range(self.num_resolutions)):
-            for i_block in range(self.num_res_blocks + 1):
-                h = self.up[i_level].block[i_block](h, temb)
-                if len(self.up[i_level].attn) > 0:
-                    h = self.up[i_level].attn[i_block](h)
-            if i_level != 0:
-                h = self.up[i_level].upsample(h)
-
-        # end
-        if self.give_pre_end:
-            return h
-
-        h = self.norm_out(h)
-        h = nonlinearity(h)
-        h = self.conv_out(h)
-        return h
-
-
-class VectorQuantizer(nn.Module):
-    """
-    Improved version over VectorQuantizer, can be used as a drop-in replacement. Mostly avoids costly matrix
-    multiplications and allows for post-hoc remapping of indices.
-    """
-
-    # NOTE: due to a bug the beta term was applied to the wrong term. for
-    # backwards compatibility we use the buggy version by default, but you can
-    # specify legacy=False to fix it.
-    def __init__(self, n_e, e_dim, beta, remap=None, unknown_index="random", sane_index_shape=False, legacy=True):
-        super().__init__()
-        self.n_e = n_e
-        self.e_dim = e_dim
-        self.beta = beta
-        self.legacy = legacy
-
-        self.embedding = nn.Embedding(self.n_e, self.e_dim)
-        self.embedding.weight.data.uniform_(-1.0 / self.n_e, 1.0 / self.n_e)
-
-        self.remap = remap
-        if self.remap is not None:
-            self.register_buffer("used", torch.tensor(np.load(self.remap)))
-            self.re_embed = self.used.shape[0]
-            self.unknown_index = unknown_index  # "random" or "extra" or integer
-            if self.unknown_index == "extra":
-                self.unknown_index = self.re_embed
-                self.re_embed = self.re_embed + 1
-            print(
-                f"Remapping {self.n_e} indices to {self.re_embed} indices. "
-                f"Using {self.unknown_index} for unknown indices."
-            )
-        else:
-            self.re_embed = n_e
-
-        self.sane_index_shape = sane_index_shape
-
-    def remap_to_used(self, inds):
-        ishape = inds.shape
-        assert len(ishape) > 1
-        inds = inds.reshape(ishape[0], -1)
-        used = self.used.to(inds)
-        match = (inds[:, :, None] == used[None, None, ...]).long()
-        new = match.argmax(-1)
-        unknown = match.sum(2) < 1
-        if self.unknown_index == "random":
-            new[unknown] = torch.randint(0, self.re_embed, size=new[unknown].shape).to(device=new.device)
-        else:
-            new[unknown] = self.unknown_index
-        return new.reshape(ishape)
-
-    def unmap_to_all(self, inds):
-        ishape = inds.shape
-        assert len(ishape) > 1
-        inds = inds.reshape(ishape[0], -1)
-        used = self.used.to(inds)
-        if self.re_embed > self.used.shape[0]:  # extra token
-            inds[inds >= self.used.shape[0]] = 0  # simply set to zero
-        back = torch.gather(used[None, :][inds.shape[0] * [0], :], 1, inds)
-        return back.reshape(ishape)
-
-    def forward(self, z, temp=None, rescale_logits=False, return_logits=False):
-        assert temp is None or temp == 1.0, "Only for interface compatible with Gumbel"
-        assert rescale_logits == False, "Only for interface compatible with Gumbel"
-        assert return_logits == False, "Only for interface compatible with Gumbel"
-        # reshape z -> (batch, height, width, channel) and flatten
-        z = rearrange(z, "b c h w -> b h w c").contiguous()
-        z_flattened = z.view(-1, self.e_dim)
-        # distances from z to embeddings e_j (z - e)^2 = z^2 + e^2 - 2 e * z
-
-        d = (
-            torch.sum(z_flattened**2, dim=1, keepdim=True)
-            + torch.sum(self.embedding.weight**2, dim=1)
-            - 2 * torch.einsum("bd,dn->bn", z_flattened, rearrange(self.embedding.weight, "n d -> d n"))
-        )
-
-        min_encoding_indices = torch.argmin(d, dim=1)
-        z_q = self.embedding(min_encoding_indices).view(z.shape)
-        perplexity = None
-        min_encodings = None
-
-        # compute loss for embedding
-        if not self.legacy:
-            loss = self.beta * torch.mean((z_q.detach() - z) ** 2) + torch.mean((z_q - z.detach()) ** 2)
-        else:
-            loss = torch.mean((z_q.detach() - z) ** 2) + self.beta * torch.mean((z_q - z.detach()) ** 2)
-
-        # preserve gradients
-        z_q = z + (z_q - z).detach()
-
-        # reshape back to match original input shape
-        z_q = rearrange(z_q, "b h w c -> b c h w").contiguous()
-
-        if self.remap is not None:
-            min_encoding_indices = min_encoding_indices.reshape(z.shape[0], -1)  # add batch axis
-            min_encoding_indices = self.remap_to_used(min_encoding_indices)
-            min_encoding_indices = min_encoding_indices.reshape(-1, 1)  # flatten
-
-        if self.sane_index_shape:
-            min_encoding_indices = min_encoding_indices.reshape(z_q.shape[0], z_q.shape[2], z_q.shape[3])
-
-        return z_q, loss, (perplexity, min_encodings, min_encoding_indices)
-
-    def get_codebook_entry(self, indices, shape):
-        # shape specifying (batch, height, width, channel)
-        if self.remap is not None:
-            indices = indices.reshape(shape[0], -1)  # add batch axis
-            indices = self.unmap_to_all(indices)
-            indices = indices.reshape(-1)  # flatten again
-
-        # get quantized latent vectors
-        z_q = self.embedding(indices)
-
-        if shape is not None:
-            z_q = z_q.view(shape)
-            # reshape back to match original input shape
-            z_q = z_q.permute(0, 3, 1, 2).contiguous()
-
-        return z_q
-
-
-class VQModel(ModelMixin, ConfigMixin):
-    def __init__(
-        self,
-        ch,
-        out_ch,
-        num_res_blocks,
-        attn_resolutions,
-        in_channels,
-        resolution,
-        z_channels,
-        n_embed,
-        embed_dim,
-        remap=None,
-        sane_index_shape=False,  # tell vector quantizer to return indices as bhw
-        ch_mult=(1, 2, 4, 8),
-        dropout=0.0,
-        double_z=True,
-        resamp_with_conv=True,
-        give_pre_end=False,
-    ):
-        super().__init__()
-
-        # register all __init__ params with self.register
-        self.register_to_config(
-            ch=ch,
-            out_ch=out_ch,
-            num_res_blocks=num_res_blocks,
-            attn_resolutions=attn_resolutions,
-            in_channels=in_channels,
-            resolution=resolution,
-            z_channels=z_channels,
-            n_embed=n_embed,
-            embed_dim=embed_dim,
-            remap=remap,
-            sane_index_shape=sane_index_shape,
-            ch_mult=ch_mult,
-            dropout=dropout,
-            double_z=double_z,
-            resamp_with_conv=resamp_with_conv,
-            give_pre_end=give_pre_end,
-        )
-
-        # pass init params to Encoder
-        self.encoder = Encoder(
-            ch=ch,
-            out_ch=out_ch,
-            num_res_blocks=num_res_blocks,
-            attn_resolutions=attn_resolutions,
-            in_channels=in_channels,
-            resolution=resolution,
-            z_channels=z_channels,
-            ch_mult=ch_mult,
-            dropout=dropout,
-            resamp_with_conv=resamp_with_conv,
-            double_z=double_z,
-            give_pre_end=give_pre_end,
-        )
-
-        self.quantize = VectorQuantizer(n_embed, embed_dim, beta=0.25, remap=remap, sane_index_shape=sane_index_shape)
-
-        # pass init params to Decoder
-        self.decoder = Decoder(
-            ch=ch,
-            out_ch=out_ch,
-            num_res_blocks=num_res_blocks,
-            attn_resolutions=attn_resolutions,
-            in_channels=in_channels,
-            resolution=resolution,
-            z_channels=z_channels,
-            ch_mult=ch_mult,
-            dropout=dropout,
-            resamp_with_conv=resamp_with_conv,
-            give_pre_end=give_pre_end,
-        )
-
-    def encode(self, x):
-        h = self.encoder(x)
-        h = self.quant_conv(h)
-        return h
-
-    def decode(self, h, force_not_quantize=False):
-        # also go through quantization layer
-        if not force_not_quantize:
-            quant, emb_loss, info = self.quantize(h)
-        else:
-            quant = h
-        quant = self.post_quant_conv(quant)
-        dec = self.decoder(quant)
-        return dec
-
-
-class DiagonalGaussianDistribution(object):
-    def __init__(self, parameters, deterministic=False):
-        self.parameters = parameters
-        self.mean, self.logvar = torch.chunk(parameters, 2, dim=1)
-        self.logvar = torch.clamp(self.logvar, -30.0, 20.0)
-        self.deterministic = deterministic
-        self.std = torch.exp(0.5 * self.logvar)
-        self.var = torch.exp(self.logvar)
-        if self.deterministic:
-            self.var = self.std = torch.zeros_like(self.mean).to(device=self.parameters.device)
-
-    def sample(self):
-        x = self.mean + self.std * torch.randn(self.mean.shape).to(device=self.parameters.device)
-        return x
-
-    def kl(self, other=None):
-        if self.deterministic:
-            return torch.Tensor([0.0])
-        else:
-            if other is None:
-                return 0.5 * torch.sum(torch.pow(self.mean, 2) + self.var - 1.0 - self.logvar, dim=[1, 2, 3])
-            else:
-                return 0.5 * torch.sum(
-                    torch.pow(self.mean - other.mean, 2) / other.var
-                    + self.var / other.var
-                    - 1.0
-                    - self.logvar
-                    + other.logvar,
-                    dim=[1, 2, 3],
-                )
-
-    def nll(self, sample, dims=[1, 2, 3]):
-        if self.deterministic:
-            return torch.Tensor([0.0])
-        logtwopi = np.log(2.0 * np.pi)
-        return 0.5 * torch.sum(logtwopi + self.logvar + torch.pow(sample - self.mean, 2) / self.var, dim=dims)
-
-    def mode(self):
-        return self.mean
-
-
-class AutoencoderKL(ModelMixin, ConfigMixin):
-    def __init__(
-        self,
-        ch,
-        out_ch,
-        num_res_blocks,
-        attn_resolutions,
-        in_channels,
-        resolution,
-        z_channels,
-        embed_dim,
-        remap=None,
-        sane_index_shape=False,  # tell vector quantizer to return indices as bhw
-        ch_mult=(1, 2, 4, 8),
-        dropout=0.0,
-        double_z=True,
-        resamp_with_conv=True,
-        give_pre_end=False,
-    ):
-        super().__init__()
-
-        # register all __init__ params with self.register
-        self.register_to_config(
-            ch=ch,
-            out_ch=out_ch,
-            num_res_blocks=num_res_blocks,
-            attn_resolutions=attn_resolutions,
-            in_channels=in_channels,
-            resolution=resolution,
-            z_channels=z_channels,
-            embed_dim=embed_dim,
-            remap=remap,
-            sane_index_shape=sane_index_shape,
-            ch_mult=ch_mult,
-            dropout=dropout,
-            double_z=double_z,
-            resamp_with_conv=resamp_with_conv,
-            give_pre_end=give_pre_end,
-        )
-
-        # pass init params to Encoder
-        self.encoder = Encoder(
-            ch=ch,
-            out_ch=out_ch,
-            num_res_blocks=num_res_blocks,
-            attn_resolutions=attn_resolutions,
-            in_channels=in_channels,
-            resolution=resolution,
-            z_channels=z_channels,
-            ch_mult=ch_mult,
-            dropout=dropout,
-            resamp_with_conv=resamp_with_conv,
-            double_z=double_z,
-            give_pre_end=give_pre_end,
-        )
-
-        # pass init params to Decoder
-        self.decoder = Decoder(
-            ch=ch,
-            out_ch=out_ch,
-            num_res_blocks=num_res_blocks,
-            attn_resolutions=attn_resolutions,
-            in_channels=in_channels,
-            resolution=resolution,
-            z_channels=z_channels,
-            ch_mult=ch_mult,
-            dropout=dropout,
-            resamp_with_conv=resamp_with_conv,
-            give_pre_end=give_pre_end,
-        )
-
-        self.quant_conv = torch.nn.Conv2d(2 * z_channels, 2 * embed_dim, 1)
-        self.post_quant_conv = torch.nn.Conv2d(embed_dim, z_channels, 1)
-
-    def encode(self, x):
-        h = self.encoder(x)
-        moments = self.quant_conv(h)
-        posterior = DiagonalGaussianDistribution(moments)
-        return posterior
-
-    def decode(self, z):
-        z = self.post_quant_conv(z)
-        dec = self.decoder(z)
-        return dec
-
-    def forward(self, input, sample_posterior=True):
-        posterior = self.encode(input)
-        if sample_posterior:
-            z = posterior.sample()
-        else:
-            z = posterior.mode()
-        dec = self.decode(z)
-        return dec, posterior
-
-
 class LatentDiffusionPipeline(DiffusionPipeline):
     def __init__(self, vqvae, bert, tokenizer, unet, noise_scheduler):
         super().__init__()

src/diffusers/pipelines/latent_diffusion_uncond/pipeline_latent_diffusion_uncond.py

-import math
-
-import numpy as np
 import torch
-import torch.nn as nn
 
 import tqdm
 
-from ...configuration_utils import ConfigMixin
-from ...modeling_utils import ModelMixin
 from ...pipeline_utils import DiffusionPipeline
 
 
-def get_timestep_embedding(timesteps, embedding_dim):
-    """
-    This matches the implementation in Denoising Diffusion Probabilistic Models: From Fairseq. Build sinusoidal
-    embeddings. This matches the implementation in tensor2tensor, but differs slightly from the description in Section
-    3.5 of "Attention Is All You Need".
-    """
-    assert len(timesteps.shape) == 1
-
-    half_dim = embedding_dim // 2
-    emb = math.log(10000) / (half_dim - 1)
-    emb = torch.exp(torch.arange(half_dim, dtype=torch.float32) * -emb)
-    emb = emb.to(device=timesteps.device)
-    emb = timesteps.float()[:, None] * emb[None, :]
-    emb = torch.cat([torch.sin(emb), torch.cos(emb)], dim=1)
-    if embedding_dim % 2 == 1:  # zero pad
-        emb = torch.nn.functional.pad(emb, (0, 1, 0, 0))
-    return emb
-
-
-def nonlinearity(x):
-    # swish
-    return x * torch.sigmoid(x)
-
-
-def Normalize(in_channels):
-    return torch.nn.GroupNorm(num_groups=32, num_channels=in_channels, eps=1e-6, affine=True)
-
-
-class Upsample(nn.Module):
-    def __init__(self, in_channels, with_conv):
-        super().__init__()
-        self.with_conv = with_conv
-        if self.with_conv:
-            self.conv = torch.nn.Conv2d(in_channels, in_channels, kernel_size=3, stride=1, padding=1)
-
-    def forward(self, x):
-        x = torch.nn.functional.interpolate(x, scale_factor=2.0, mode="nearest")
-        if self.with_conv:
-            x = self.conv(x)
-        return x
-
-
-class Downsample(nn.Module):
-    def __init__(self, in_channels, with_conv):
-        super().__init__()
-        self.with_conv = with_conv
-        if self.with_conv:
-            # no asymmetric padding in torch conv, must do it ourselves
-            self.conv = torch.nn.Conv2d(in_channels, in_channels, kernel_size=3, stride=2, padding=0)
-
-    def forward(self, x):
-        if self.with_conv:
-            pad = (0, 1, 0, 1)
-            x = torch.nn.functional.pad(x, pad, mode="constant", value=0)
-            x = self.conv(x)
-        else:
-            x = torch.nn.functional.avg_pool2d(x, kernel_size=2, stride=2)
-        return x
-
-
-class ResnetBlock(nn.Module):
-    def __init__(self, *, in_channels, out_channels=None, conv_shortcut=False, dropout, temb_channels=512):
-        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.use_conv_shortcut = conv_shortcut
-
-        self.norm1 = Normalize(in_channels)
-        self.conv1 = torch.nn.Conv2d(in_channels, out_channels, kernel_size=3, stride=1, padding=1)
-        if temb_channels > 0:
-            self.temb_proj = torch.nn.Linear(temb_channels, out_channels)
-        self.norm2 = Normalize(out_channels)
-        self.dropout = torch.nn.Dropout(dropout)
-        self.conv2 = torch.nn.Conv2d(out_channels, out_channels, kernel_size=3, stride=1, padding=1)
-        if self.in_channels != self.out_channels:
-            if self.use_conv_shortcut:
-                self.conv_shortcut = torch.nn.Conv2d(in_channels, out_channels, kernel_size=3, stride=1, padding=1)
-            else:
-                self.nin_shortcut = torch.nn.Conv2d(in_channels, out_channels, kernel_size=1, stride=1, padding=0)
-
-    def forward(self, x, temb):
-        h = x
-        h = self.norm1(h)
-        h = nonlinearity(h)
-        h = self.conv1(h)
-
-        if temb is not None:
-            h = h + self.temb_proj(nonlinearity(temb))[:, :, None, None]
-
-        h = self.norm2(h)
-        h = nonlinearity(h)
-        h = self.dropout(h)
-        h = self.conv2(h)
-
-        if self.in_channels != self.out_channels:
-            if self.use_conv_shortcut:
-                x = self.conv_shortcut(x)
-            else:
-                x = self.nin_shortcut(x)
-
-        return x + h
-
-
-class AttnBlock(nn.Module):
-    def __init__(self, in_channels):
-        super().__init__()
-        self.in_channels = in_channels
-
-        self.norm = Normalize(in_channels)
-        self.q = torch.nn.Conv2d(in_channels, in_channels, kernel_size=1, stride=1, padding=0)
-        self.k = torch.nn.Conv2d(in_channels, in_channels, kernel_size=1, stride=1, padding=0)
-        self.v = torch.nn.Conv2d(in_channels, in_channels, kernel_size=1, stride=1, padding=0)
-        self.proj_out = torch.nn.Conv2d(in_channels, in_channels, kernel_size=1, stride=1, padding=0)
-
-    def forward(self, x):
-        h_ = x
-        h_ = self.norm(h_)
-        q = self.q(h_)
-        k = self.k(h_)
-        v = self.v(h_)
-
-        # compute attention
-        b, c, h, w = q.shape
-        q = q.reshape(b, c, h * w)
-        q = q.permute(0, 2, 1)  # b,hw,c
-        k = k.reshape(b, c, h * w)  # b,c,hw
-        w_ = torch.bmm(q, k)  # b,hw,hw    w[b,i,j]=sum_c q[b,i,c]k[b,c,j]
-        w_ = w_ * (int(c) ** (-0.5))
-        w_ = torch.nn.functional.softmax(w_, dim=2)
-
-        # attend to values
-        v = v.reshape(b, c, h * w)
-        w_ = w_.permute(0, 2, 1)  # b,hw,hw (first hw of k, second of q)
-        h_ = torch.bmm(v, w_)  # b, c,hw (hw of q) h_[b,c,j] = sum_i v[b,c,i] w_[b,i,j]
-        h_ = h_.reshape(b, c, h, w)
-
-        h_ = self.proj_out(h_)
-
-        return x + h_
-
-
-class Encoder(nn.Module):
-    def __init__(
-        self,
-        *,
-        ch,
-        out_ch,
-        ch_mult=(1, 2, 4, 8),
-        num_res_blocks,
-        attn_resolutions,
-        dropout=0.0,
-        resamp_with_conv=True,
-        in_channels,
-        resolution,
-        z_channels,
-        double_z=True,
-        **ignore_kwargs,
-    ):
-        super().__init__()
-        self.ch = ch
-        self.temb_ch = 0
-        self.num_resolutions = len(ch_mult)
-        self.num_res_blocks = num_res_blocks
-        self.resolution = resolution
-        self.in_channels = in_channels
-
-        # downsampling
-        self.conv_in = torch.nn.Conv2d(in_channels, self.ch, kernel_size=3, stride=1, padding=1)
-
-        curr_res = resolution
-        in_ch_mult = (1,) + tuple(ch_mult)
-        self.down = nn.ModuleList()
-        for i_level in range(self.num_resolutions):
-            block = nn.ModuleList()
-            attn = nn.ModuleList()
-            block_in = ch * in_ch_mult[i_level]
-            block_out = ch * ch_mult[i_level]
-            for i_block in range(self.num_res_blocks):
-                block.append(
-                    ResnetBlock(
-                        in_channels=block_in, out_channels=block_out, temb_channels=self.temb_ch, dropout=dropout
-                    )
-                )
-                block_in = block_out
-                if curr_res in attn_resolutions:
-                    attn.append(AttnBlock(block_in))
-            down = nn.Module()
-            down.block = block
-            down.attn = attn
-            if i_level != self.num_resolutions - 1:
-                down.downsample = Downsample(block_in, resamp_with_conv)
-                curr_res = curr_res // 2
-            self.down.append(down)
-
-        # middle
-        self.mid = nn.Module()
-        self.mid.block_1 = ResnetBlock(
-            in_channels=block_in, out_channels=block_in, temb_channels=self.temb_ch, dropout=dropout
-        )
-        self.mid.attn_1 = AttnBlock(block_in)
-        self.mid.block_2 = ResnetBlock(
-            in_channels=block_in, out_channels=block_in, temb_channels=self.temb_ch, dropout=dropout
-        )
-
-        # end
-        self.norm_out = Normalize(block_in)
-        self.conv_out = torch.nn.Conv2d(
-            block_in, 2 * z_channels if double_z else z_channels, kernel_size=3, stride=1, padding=1
-        )
-
-    def forward(self, x):
-        # assert x.shape[2] == x.shape[3] == self.resolution, "{}, {}, {}".format(x.shape[2], x.shape[3], self.resolution)
-
-        # timestep embedding
-        temb = None
-
-        # downsampling
-        hs = [self.conv_in(x)]
-        for i_level in range(self.num_resolutions):
-            for i_block in range(self.num_res_blocks):
-                h = self.down[i_level].block[i_block](hs[-1], temb)
-                if len(self.down[i_level].attn) > 0:
-                    h = self.down[i_level].attn[i_block](h)
-                hs.append(h)
-            if i_level != self.num_resolutions - 1:
-                hs.append(self.down[i_level].downsample(hs[-1]))
-
-        # middle
-        h = hs[-1]
-        h = self.mid.block_1(h, temb)
-        h = self.mid.attn_1(h)
-        h = self.mid.block_2(h, temb)
-
-        # end
-        h = self.norm_out(h)
-        h = nonlinearity(h)
-        h = self.conv_out(h)
-        return h
-
-
-class Decoder(nn.Module):
-    def __init__(
-        self,
-        *,
-        ch,
-        out_ch,
-        ch_mult=(1, 2, 4, 8),
-        num_res_blocks,
-        attn_resolutions,
-        dropout=0.0,
-        resamp_with_conv=True,
-        in_channels,
-        resolution,
-        z_channels,
-        give_pre_end=False,
-        **ignorekwargs,
-    ):
-        super().__init__()
-        self.ch = ch
-        self.temb_ch = 0
-        self.num_resolutions = len(ch_mult)
-        self.num_res_blocks = num_res_blocks
-        self.resolution = resolution
-        self.in_channels = in_channels
-        self.give_pre_end = give_pre_end
-
-        # compute in_ch_mult, block_in and curr_res at lowest res
-        block_in = ch * ch_mult[self.num_resolutions - 1]
-        curr_res = resolution // 2 ** (self.num_resolutions - 1)
-        self.z_shape = (1, z_channels, curr_res, curr_res)
-        print("Working with z of shape {} = {} dimensions.".format(self.z_shape, np.prod(self.z_shape)))
-
-        # z to block_in
-        self.conv_in = torch.nn.Conv2d(z_channels, block_in, kernel_size=3, stride=1, padding=1)
-
-        # middle
-        self.mid = nn.Module()
-        self.mid.block_1 = ResnetBlock(
-            in_channels=block_in, out_channels=block_in, temb_channels=self.temb_ch, dropout=dropout
-        )
-        self.mid.attn_1 = AttnBlock(block_in)
-        self.mid.block_2 = ResnetBlock(
-            in_channels=block_in, out_channels=block_in, temb_channels=self.temb_ch, dropout=dropout
-        )
-
-        # upsampling
-        self.up = nn.ModuleList()
-        for i_level in reversed(range(self.num_resolutions)):
-            block = nn.ModuleList()
-            attn = nn.ModuleList()
-            block_out = ch * ch_mult[i_level]
-            for i_block in range(self.num_res_blocks + 1):
-                block.append(
-                    ResnetBlock(
-                        in_channels=block_in, out_channels=block_out, temb_channels=self.temb_ch, dropout=dropout
-                    )
-                )
-                block_in = block_out
-                if curr_res in attn_resolutions:
-                    attn.append(AttnBlock(block_in))
-            up = nn.Module()
-            up.block = block
-            up.attn = attn
-            if i_level != 0:
-                up.upsample = Upsample(block_in, resamp_with_conv)
-                curr_res = curr_res * 2
-            self.up.insert(0, up)  # prepend to get consistent order
-
-        # end
-        self.norm_out = Normalize(block_in)
-        self.conv_out = torch.nn.Conv2d(block_in, out_ch, kernel_size=3, stride=1, padding=1)
-
-    def forward(self, z):
-        # assert z.shape[1:] == self.z_shape[1:]
-        self.last_z_shape = z.shape
-
-        # timestep embedding
-        temb = None
-
-        # z to block_in
-        h = self.conv_in(z)
-
-        # middle
-        h = self.mid.block_1(h, temb)
-        h = self.mid.attn_1(h)
-        h = self.mid.block_2(h, temb)
-
-        # upsampling
-        for i_level in reversed(range(self.num_resolutions)):
-            for i_block in range(self.num_res_blocks + 1):
-                h = self.up[i_level].block[i_block](h, temb)
-                if len(self.up[i_level].attn) > 0:
-                    h = self.up[i_level].attn[i_block](h)
-            if i_level != 0:
-                h = self.up[i_level].upsample(h)
-
-        # end
-        if self.give_pre_end:
-            return h
-
-        h = self.norm_out(h)
-        h = nonlinearity(h)
-        h = self.conv_out(h)
-        return h
-
-
-class VectorQuantizer(nn.Module):
-    """
-    Improved version over VectorQuantizer, can be used as a drop-in replacement. Mostly avoids costly matrix
-    multiplications and allows for post-hoc remapping of indices.
-    """
-
-    # NOTE: due to a bug the beta term was applied to the wrong term. for
-    # backwards compatibility we use the buggy version by default, but you can
-    # specify legacy=False to fix it.
-    def __init__(self, n_e, e_dim, beta, remap=None, unknown_index="random", sane_index_shape=False, legacy=True):
-        super().__init__()
-        self.n_e = n_e
-        self.e_dim = e_dim
-        self.beta = beta
-        self.legacy = legacy
-
-        self.embedding = nn.Embedding(self.n_e, self.e_dim)
-        self.embedding.weight.data.uniform_(-1.0 / self.n_e, 1.0 / self.n_e)
-
-        self.remap = remap
-        if self.remap is not None:
-            self.register_buffer("used", torch.tensor(np.load(self.remap)))
-            self.re_embed = self.used.shape[0]
-            self.unknown_index = unknown_index  # "random" or "extra" or integer
-            if self.unknown_index == "extra":
-                self.unknown_index = self.re_embed
-                self.re_embed = self.re_embed + 1
-            print(
-                f"Remapping {self.n_e} indices to {self.re_embed} indices. "
-                f"Using {self.unknown_index} for unknown indices."
-            )
-        else:
-            self.re_embed = n_e
-
-        self.sane_index_shape = sane_index_shape
-
-    def remap_to_used(self, inds):
-        ishape = inds.shape
-        assert len(ishape) > 1
-        inds = inds.reshape(ishape[0], -1)
-        used = self.used.to(inds)
-        match = (inds[:, :, None] == used[None, None, ...]).long()
-        new = match.argmax(-1)
-        unknown = match.sum(2) < 1
-        if self.unknown_index == "random":
-            new[unknown] = torch.randint(0, self.re_embed, size=new[unknown].shape).to(device=new.device)
-        else:
-            new[unknown] = self.unknown_index
-        return new.reshape(ishape)
-
-    def unmap_to_all(self, inds):
-        ishape = inds.shape
-        assert len(ishape) > 1
-        inds = inds.reshape(ishape[0], -1)
-        used = self.used.to(inds)
-        if self.re_embed > self.used.shape[0]:  # extra token
-            inds[inds >= self.used.shape[0]] = 0  # simply set to zero
-        back = torch.gather(used[None, :][inds.shape[0] * [0], :], 1, inds)
-        return back.reshape(ishape)
-
-    def forward(self, z):
-        # reshape z -> (batch, height, width, channel) and flatten
-        z = z.permute(0, 2, 3, 1).contiguous()
-        z_flattened = z.view(-1, self.e_dim)
-        # distances from z to embeddings e_j (z - e)^2 = z^2 + e^2 - 2 e * z
-
-        d = (
-            torch.sum(z_flattened**2, dim=1, keepdim=True)
-            + torch.sum(self.embedding.weight**2, dim=1)
-            - 2 * torch.einsum("bd,dn->bn", z_flattened, self.embedding.weight.t())
-        )
-
-        min_encoding_indices = torch.argmin(d, dim=1)
-        z_q = self.embedding(min_encoding_indices).view(z.shape)
-        perplexity = None
-        min_encodings = None
-
-        # compute loss for embedding
-        if not self.legacy:
-            loss = self.beta * torch.mean((z_q.detach() - z) ** 2) + torch.mean((z_q - z.detach()) ** 2)
-        else:
-            loss = torch.mean((z_q.detach() - z) ** 2) + self.beta * torch.mean((z_q - z.detach()) ** 2)
-
-        # preserve gradients
-        z_q = z + (z_q - z).detach()
-
-        # reshape back to match original input shape
-        z_q = z_q.permute(0, 3, 1, 2).contiguous()
-
-        if self.remap is not None:
-            min_encoding_indices = min_encoding_indices.reshape(z.shape[0], -1)  # add batch axis
-            min_encoding_indices = self.remap_to_used(min_encoding_indices)
-            min_encoding_indices = min_encoding_indices.reshape(-1, 1)  # flatten
-
-        if self.sane_index_shape:
-            min_encoding_indices = min_encoding_indices.reshape(z_q.shape[0], z_q.shape[2], z_q.shape[3])
-
-        return z_q, loss, (perplexity, min_encodings, min_encoding_indices)
-
-    def get_codebook_entry(self, indices, shape):
-        # shape specifying (batch, height, width, channel)
-        if self.remap is not None:
-            indices = indices.reshape(shape[0], -1)  # add batch axis
-            indices = self.unmap_to_all(indices)
-            indices = indices.reshape(-1)  # flatten again
-
-        # get quantized latent vectors
-        z_q = self.embedding(indices)
-
-        if shape is not None:
-            z_q = z_q.view(shape)
-            # reshape back to match original input shape
-            z_q = z_q.permute(0, 3, 1, 2).contiguous()
-
-        return z_q
-
-
-class VQModel(ModelMixin, ConfigMixin):
-    def __init__(
-        self,
-        ch,
-        out_ch,
-        num_res_blocks,
-        attn_resolutions,
-        in_channels,
-        resolution,
-        z_channels,
-        n_embed,
-        embed_dim,
-        remap=None,
-        sane_index_shape=False,  # tell vector quantizer to return indices as bhw
-        ch_mult=(1, 2, 4, 8),
-        dropout=0.0,
-        double_z=True,
-        resamp_with_conv=True,
-        give_pre_end=False,
-    ):
-        super().__init__()
-
-        # register all __init__ params with self.register
-        self.register_to_config(
-            ch=ch,
-            out_ch=out_ch,
-            num_res_blocks=num_res_blocks,
-            attn_resolutions=attn_resolutions,
-            in_channels=in_channels,
-            resolution=resolution,
-            z_channels=z_channels,
-            n_embed=n_embed,
-            embed_dim=embed_dim,
-            remap=remap,
-            sane_index_shape=sane_index_shape,
-            ch_mult=ch_mult,
-            dropout=dropout,
-            double_z=double_z,
-            resamp_with_conv=resamp_with_conv,
-            give_pre_end=give_pre_end,
-        )
-
-        # pass init params to Encoder
-        self.encoder = Encoder(
-            ch=ch,
-            out_ch=out_ch,
-            num_res_blocks=num_res_blocks,
-            attn_resolutions=attn_resolutions,
-            in_channels=in_channels,
-            resolution=resolution,
-            z_channels=z_channels,
-            ch_mult=ch_mult,
-            dropout=dropout,
-            resamp_with_conv=resamp_with_conv,
-            double_z=double_z,
-            give_pre_end=give_pre_end,
-        )
-
-        self.quantize = VectorQuantizer(n_embed, embed_dim, beta=0.25, remap=remap, sane_index_shape=sane_index_shape)
-
-        # pass init params to Decoder
-        self.decoder = Decoder(
-            ch=ch,
-            out_ch=out_ch,
-            num_res_blocks=num_res_blocks,
-            attn_resolutions=attn_resolutions,
-            in_channels=in_channels,
-            resolution=resolution,
-            z_channels=z_channels,
-            ch_mult=ch_mult,
-            dropout=dropout,
-            resamp_with_conv=resamp_with_conv,
-            give_pre_end=give_pre_end,
-        )
-
-    def encode(self, x):
-        h = self.encoder(x)
-        h = self.quant_conv(h)
-        return h
-
-    def decode(self, h, force_not_quantize=False):
-        # also go through quantization layer
-        if not force_not_quantize:
-            quant, emb_loss, info = self.quantize(h)
-        else:
-            quant = h
-        quant = self.post_quant_conv(quant)
-        dec = self.decoder(quant)
-        return dec
-
-
 class LatentDiffusionUncondPipeline(DiffusionPipeline):
     def __init__(self, vqvae, unet, noise_scheduler):
         super().__init__()

tests/test_modeling_utils.py

@@ -22,6 +22,7 @@ import numpy as np
 import torch
 
 from diffusers import (
+    AutoencoderKL,
     BDDMPipeline,
     DDIMPipeline,
     DDIMScheduler,
@@ -44,6 +45,8 @@ from diffusers import (
     UNetGradTTSModel,
     UNetLDMModel,
     UNetModel,
+    VQModel,
+    AutoencoderKL,
 )
 from diffusers.configuration_utils import ConfigMixin
 from diffusers.pipeline_utils import DiffusionPipeline
@@ -805,6 +808,154 @@ class NCSNppModelTests(ModelTesterMixin, unittest.TestCase):
         self.assertTrue(torch.allclose(output_slice, expected_output_slice, atol=1e-3))
 
 
+class VQModelTests(ModelTesterMixin, unittest.TestCase):
+    model_class = VQModel
+
+    @property
+    def dummy_input(self):
+        batch_size = 4
+        num_channels = 3
+        sizes = (32, 32)
+
+        image = floats_tensor((batch_size, num_channels) + sizes).to(torch_device)
+
+        return {"x": image}
+
+    @property
+    def input_shape(self):
+        return (3, 32, 32)
+
+    @property
+    def output_shape(self):
+        return (3, 32, 32)
+
+    def prepare_init_args_and_inputs_for_common(self):
+        init_dict = {
+            "ch": 64,
+            "out_ch": 3,
+            "num_res_blocks": 1,
+            "attn_resolutions": [],
+            "in_channels": 3,
+            "resolution": 32,
+            "z_channels": 3,
+            "n_embed": 256,
+            "embed_dim": 3,
+            "sane_index_shape": False,
+            "ch_mult": (1,),
+            "dropout": 0.0,
+            "double_z": False,
+        }
+        inputs_dict = self.dummy_input
+        return init_dict, inputs_dict
+
+    def test_forward_signature(self):
+        pass
+
+    def test_training(self):
+        pass
+
+    def test_from_pretrained_hub(self):
+        model, loading_info = VQModel.from_pretrained("fusing/vqgan-dummy", output_loading_info=True)
+        self.assertIsNotNone(model)
+        self.assertEqual(len(loading_info["missing_keys"]), 0)
+
+        model.to(torch_device)
+        image = model(**self.dummy_input)
+
+        assert image is not None, "Make sure output is not None"
+
+    def test_output_pretrained(self):
+        model = VQModel.from_pretrained("fusing/vqgan-dummy")
+        model.eval()
+
+        torch.manual_seed(0)
+        if torch.cuda.is_available():
+            torch.cuda.manual_seed_all(0)
+
+        image = torch.randn(1, model.config.in_channels, model.config.resolution, model.config.resolution)
+        with torch.no_grad():
+            output = model(image)
+
+        output_slice = output[0, -1, -3:, -3:].flatten()
+        # fmt: off
+        expected_output_slice = torch.tensor([-1.1321,  0.1056,  0.3505, -0.6461, -0.2014,  0.0419, -0.5763, -0.8462,
+        -0.4218])
+        # fmt: on
+        self.assertTrue(torch.allclose(output_slice, expected_output_slice, atol=1e-3))
+
+
+class AutoEncoderKLTests(ModelTesterMixin, unittest.TestCase):
+    model_class = AutoencoderKL
+
+    @property
+    def dummy_input(self):
+        batch_size = 4
+        num_channels = 3
+        sizes = (32, 32)
+
+        image = floats_tensor((batch_size, num_channels) + sizes).to(torch_device)
+
+        return {"x": image}
+
+    @property
+    def input_shape(self):
+        return (3, 32, 32)
+
+    @property
+    def output_shape(self):
+        return (3, 32, 32)
+
+    def prepare_init_args_and_inputs_for_common(self):
+        init_dict = {
+            "ch": 64,
+            "ch_mult": (1,),
+            "embed_dim": 4,
+            "in_channels": 3,
+            "num_res_blocks": 1,
+            "out_ch": 3,
+            "resolution": 32,
+            "z_channels": 4,
+            "attn_resolutions": []
+        }
+        inputs_dict = self.dummy_input
+        return init_dict, inputs_dict
+
+    def test_forward_signature(self):
+        pass
+
+    def test_training(self):
+        pass
+    
+    def test_from_pretrained_hub(self):
+        model, loading_info = AutoencoderKL.from_pretrained("fusing/autoencoder-kl-dummy", output_loading_info=True)
+        self.assertIsNotNone(model)
+        self.assertEqual(len(loading_info["missing_keys"]), 0)
+
+        model.to(torch_device)
+        image = model(**self.dummy_input)
+
+        assert image is not None, "Make sure output is not None"
+
+    def test_output_pretrained(self):
+        model = AutoencoderKL.from_pretrained("fusing/autoencoder-kl-dummy")
+        model.eval()
+
+        torch.manual_seed(0)
+        if torch.cuda.is_available():
+            torch.cuda.manual_seed_all(0)
+
+        image = torch.randn(1, model.config.in_channels, model.config.resolution, model.config.resolution)
+        with torch.no_grad():
+            output = model(image, sample_posterior=True)
+
+        output_slice = output[0, -1, -3:, -3:].flatten()
+        # fmt: off
+        expected_output_slice = torch.tensor([-0.0814, -0.0229, -0.1320, -0.4123, -0.0366, -0.3473,  0.0438, -0.1662,
+         0.1750])
+        # fmt: on
+        self.assertTrue(torch.allclose(output_slice, expected_output_slice, atol=1e-3))
+
+
 class PipelineTesterMixin(unittest.TestCase):
     def test_from_pretrained_save_pretrained(self):
         # 1. Load models