更新diffusers文件夹

diffusers-0.27.0/src/diffusers/models/dual_transformer_2d.py

+# Copyright 2024 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 ..utils import deprecate
+from .transformers.dual_transformer_2d import DualTransformer2DModel
+
+
+class DualTransformer2DModel(DualTransformer2DModel):
+    deprecation_message = "Importing `DualTransformer2DModel` from `diffusers.models.dual_transformer_2d` is deprecated and this will be removed in a future version. Please use `from diffusers.models.transformers.dual_transformer_2d import DualTransformer2DModel`, instead."
+    deprecate("DualTransformer2DModel", "0.29", deprecation_message)

diffusers-0.27.0/src/diffusers/models/embeddings.py

+# Copyright 2024 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.
+import math
+from typing import List, Optional, Tuple, Union
+
+import numpy as np
+import torch
+from torch import nn
+
+from ..utils import deprecate
+from .activations import get_activation
+from .attention_processor import Attention
+
+
+def get_timestep_embedding(
+    timesteps: torch.Tensor,
+    embedding_dim: int,
+    flip_sin_to_cos: bool = False,
+    downscale_freq_shift: float = 1,
+    scale: float = 1,
+    max_period: int = 10000,
+):
+    """
+    This matches the implementation in Denoising Diffusion Probabilistic Models: Create sinusoidal timestep embeddings.
+
+    :param timesteps: a 1-D Tensor of N indices, one per batch element.
+                      These may be fractional.
+    :param embedding_dim: the dimension of the output. :param max_period: controls the minimum frequency of the
+    embeddings. :return: an [N x dim] Tensor of positional embeddings.
+    """
+    assert len(timesteps.shape) == 1, "Timesteps should be a 1d-array"
+
+    half_dim = embedding_dim // 2
+    exponent = -math.log(max_period) * torch.arange(
+        start=0, end=half_dim, dtype=torch.float32, device=timesteps.device
+    )
+    exponent = exponent / (half_dim - downscale_freq_shift)
+
+    emb = torch.exp(exponent)
+    emb = timesteps[:, None].float() * emb[None, :]
+
+    # scale embeddings
+    emb = scale * emb
+
+    # concat sine and cosine embeddings
+    emb = torch.cat([torch.sin(emb), torch.cos(emb)], dim=-1)
+
+    # flip sine and cosine embeddings
+    if flip_sin_to_cos:
+        emb = torch.cat([emb[:, half_dim:], emb[:, :half_dim]], dim=-1)
+
+    # zero pad
+    if embedding_dim % 2 == 1:
+        emb = torch.nn.functional.pad(emb, (0, 1, 0, 0))
+    return emb
+
+
+def get_2d_sincos_pos_embed(
+    embed_dim, grid_size, cls_token=False, extra_tokens=0, interpolation_scale=1.0, base_size=16
+):
+    """
+    grid_size: int of the grid height and width return: pos_embed: [grid_size*grid_size, embed_dim] or
+    [1+grid_size*grid_size, embed_dim] (w/ or w/o cls_token)
+    """
+    if isinstance(grid_size, int):
+        grid_size = (grid_size, grid_size)
+
+    grid_h = np.arange(grid_size[0], dtype=np.float32) / (grid_size[0] / base_size) / interpolation_scale
+    grid_w = np.arange(grid_size[1], dtype=np.float32) / (grid_size[1] / base_size) / interpolation_scale
+    grid = np.meshgrid(grid_w, grid_h)  # here w goes first
+    grid = np.stack(grid, axis=0)
+
+    grid = grid.reshape([2, 1, grid_size[1], grid_size[0]])
+    pos_embed = get_2d_sincos_pos_embed_from_grid(embed_dim, grid)
+    if cls_token and extra_tokens > 0:
+        pos_embed = np.concatenate([np.zeros([extra_tokens, embed_dim]), pos_embed], axis=0)
+    return pos_embed
+
+
+def get_2d_sincos_pos_embed_from_grid(embed_dim, grid):
+    if embed_dim % 2 != 0:
+        raise ValueError("embed_dim must be divisible by 2")
+
+    # use half of dimensions to encode grid_h
+    emb_h = get_1d_sincos_pos_embed_from_grid(embed_dim // 2, grid[0])  # (H*W, D/2)
+    emb_w = get_1d_sincos_pos_embed_from_grid(embed_dim // 2, grid[1])  # (H*W, D/2)
+
+    emb = np.concatenate([emb_h, emb_w], axis=1)  # (H*W, D)
+    return emb
+
+
+def get_1d_sincos_pos_embed_from_grid(embed_dim, pos):
+    """
+    embed_dim: output dimension for each position pos: a list of positions to be encoded: size (M,) out: (M, D)
+    """
+    if embed_dim % 2 != 0:
+        raise ValueError("embed_dim must be divisible by 2")
+
+    omega = np.arange(embed_dim // 2, dtype=np.float64)
+    omega /= embed_dim / 2.0
+    omega = 1.0 / 10000**omega  # (D/2,)
+
+    pos = pos.reshape(-1)  # (M,)
+    out = np.einsum("m,d->md", pos, omega)  # (M, D/2), outer product
+
+    emb_sin = np.sin(out)  # (M, D/2)
+    emb_cos = np.cos(out)  # (M, D/2)
+
+    emb = np.concatenate([emb_sin, emb_cos], axis=1)  # (M, D)
+    return emb
+
+
+class PatchEmbed(nn.Module):
+    """2D Image to Patch Embedding"""
+
+    def __init__(
+        self,
+        height=224,
+        width=224,
+        patch_size=16,
+        in_channels=3,
+        embed_dim=768,
+        layer_norm=False,
+        flatten=True,
+        bias=True,
+        interpolation_scale=1,
+    ):
+        super().__init__()
+
+        num_patches = (height // patch_size) * (width // patch_size)
+        self.flatten = flatten
+        self.layer_norm = layer_norm
+
+        self.proj = nn.Conv2d(
+            in_channels, embed_dim, kernel_size=(patch_size, patch_size), stride=patch_size, bias=bias
+        )
+        if layer_norm:
+            self.norm = nn.LayerNorm(embed_dim, elementwise_affine=False, eps=1e-6)
+        else:
+            self.norm = None
+
+        self.patch_size = patch_size
+        # See:
+        # https://github.com/PixArt-alpha/PixArt-alpha/blob/0f55e922376d8b797edd44d25d0e7464b260dcab/diffusion/model/nets/PixArtMS.py#L161
+        self.height, self.width = height // patch_size, width // patch_size
+        self.base_size = height // patch_size
+        self.interpolation_scale = interpolation_scale
+        pos_embed = get_2d_sincos_pos_embed(
+            embed_dim, int(num_patches**0.5), base_size=self.base_size, interpolation_scale=self.interpolation_scale
+        )
+        self.register_buffer("pos_embed", torch.from_numpy(pos_embed).float().unsqueeze(0), persistent=False)
+
+    def forward(self, latent):
+        height, width = latent.shape[-2] // self.patch_size, latent.shape[-1] // self.patch_size
+
+        latent = self.proj(latent)
+        if self.flatten:
+            latent = latent.flatten(2).transpose(1, 2)  # BCHW -> BNC
+        if self.layer_norm:
+            latent = self.norm(latent)
+
+        # Interpolate positional embeddings if needed.
+        # (For PixArt-Alpha: https://github.com/PixArt-alpha/PixArt-alpha/blob/0f55e922376d8b797edd44d25d0e7464b260dcab/diffusion/model/nets/PixArtMS.py#L162C151-L162C160)
+        if self.height != height or self.width != width:
+            pos_embed = get_2d_sincos_pos_embed(
+                embed_dim=self.pos_embed.shape[-1],
+                grid_size=(height, width),
+                base_size=self.base_size,
+                interpolation_scale=self.interpolation_scale,
+            )
+            pos_embed = torch.from_numpy(pos_embed)
+            pos_embed = pos_embed.float().unsqueeze(0).to(latent.device)
+        else:
+            pos_embed = self.pos_embed
+
+        return (latent + pos_embed).to(latent.dtype)
+
+
+class TimestepEmbedding(nn.Module):
+    def __init__(
+        self,
+        in_channels: int,
+        time_embed_dim: int,
+        act_fn: str = "silu",
+        out_dim: int = None,
+        post_act_fn: Optional[str] = None,
+        cond_proj_dim=None,
+        sample_proj_bias=True,
+    ):
+        super().__init__()
+        linear_cls = nn.Linear
+
+        self.linear_1 = linear_cls(in_channels, time_embed_dim, sample_proj_bias)
+
+        if cond_proj_dim is not None:
+            self.cond_proj = nn.Linear(cond_proj_dim, in_channels, bias=False)
+        else:
+            self.cond_proj = None
+
+        self.act = get_activation(act_fn)
+
+        if out_dim is not None:
+            time_embed_dim_out = out_dim
+        else:
+            time_embed_dim_out = time_embed_dim
+        self.linear_2 = linear_cls(time_embed_dim, time_embed_dim_out, sample_proj_bias)
+
+        if post_act_fn is None:
+            self.post_act = None
+        else:
+            self.post_act = get_activation(post_act_fn)
+
+    def forward(self, sample, condition=None):
+        if condition is not None:
+            sample = sample + self.cond_proj(condition)
+        sample = self.linear_1(sample)
+
+        if self.act is not None:
+            sample = self.act(sample)
+
+        sample = self.linear_2(sample)
+
+        if self.post_act is not None:
+            sample = self.post_act(sample)
+        return sample
+
+
+class Timesteps(nn.Module):
+    def __init__(self, num_channels: int, flip_sin_to_cos: bool, downscale_freq_shift: float):
+        super().__init__()
+        self.num_channels = num_channels
+        self.flip_sin_to_cos = flip_sin_to_cos
+        self.downscale_freq_shift = downscale_freq_shift
+
+    def forward(self, timesteps):
+        t_emb = get_timestep_embedding(
+            timesteps,
+            self.num_channels,
+            flip_sin_to_cos=self.flip_sin_to_cos,
+            downscale_freq_shift=self.downscale_freq_shift,
+        )
+        return t_emb
+
+
+class GaussianFourierProjection(nn.Module):
+    """Gaussian Fourier embeddings for noise levels."""
+
+    def __init__(
+        self, embedding_size: int = 256, scale: float = 1.0, set_W_to_weight=True, log=True, flip_sin_to_cos=False
+    ):
+        super().__init__()
+        self.weight = nn.Parameter(torch.randn(embedding_size) * scale, requires_grad=False)
+        self.log = log
+        self.flip_sin_to_cos = flip_sin_to_cos
+
+        if set_W_to_weight:
+            # to delete later
+            self.W = nn.Parameter(torch.randn(embedding_size) * scale, requires_grad=False)
+
+            self.weight = self.W
+
+    def forward(self, x):
+        if self.log:
+            x = torch.log(x)
+
+        x_proj = x[:, None] * self.weight[None, :] * 2 * np.pi
+
+        if self.flip_sin_to_cos:
+            out = torch.cat([torch.cos(x_proj), torch.sin(x_proj)], dim=-1)
+        else:
+            out = torch.cat([torch.sin(x_proj), torch.cos(x_proj)], dim=-1)
+        return out
+
+
+class SinusoidalPositionalEmbedding(nn.Module):
+    """Apply positional information to a sequence of embeddings.
+
+    Takes in a sequence of embeddings with shape (batch_size, seq_length, embed_dim) and adds positional embeddings to
+    them
+
+    Args:
+        embed_dim: (int): Dimension of the positional embedding.
+        max_seq_length: Maximum sequence length to apply positional embeddings
+
+    """
+
+    def __init__(self, embed_dim: int, max_seq_length: int = 32):
+        super().__init__()
+        position = torch.arange(max_seq_length).unsqueeze(1)
+        div_term = torch.exp(torch.arange(0, embed_dim, 2) * (-math.log(10000.0) / embed_dim))
+        pe = torch.zeros(1, max_seq_length, embed_dim)
+        pe[0, :, 0::2] = torch.sin(position * div_term)
+        pe[0, :, 1::2] = torch.cos(position * div_term)
+        self.register_buffer("pe", pe)
+
+    def forward(self, x):
+        _, seq_length, _ = x.shape
+        x = x + self.pe[:, :seq_length]
+        return x
+
+
+class ImagePositionalEmbeddings(nn.Module):
+    """
+    Converts latent image classes into vector embeddings. Sums the vector embeddings with positional embeddings for the
+    height and width of the latent space.
+
+    For more details, see figure 10 of the dall-e paper: https://arxiv.org/abs/2102.12092
+
+    For VQ-diffusion:
+
+    Output vector embeddings are used as input for the transformer.
+
+    Note that the vector embeddings for the transformer are different than the vector embeddings from the VQVAE.
+
+    Args:
+        num_embed (`int`):
+            Number of embeddings for the latent pixels embeddings.
+        height (`int`):
+            Height of the latent image i.e. the number of height embeddings.
+        width (`int`):
+            Width of the latent image i.e. the number of width embeddings.
+        embed_dim (`int`):
+            Dimension of the produced vector embeddings. Used for the latent pixel, height, and width embeddings.
+    """
+
+    def __init__(
+        self,
+        num_embed: int,
+        height: int,
+        width: int,
+        embed_dim: int,
+    ):
+        super().__init__()
+
+        self.height = height
+        self.width = width
+        self.num_embed = num_embed
+        self.embed_dim = embed_dim
+
+        self.emb = nn.Embedding(self.num_embed, embed_dim)
+        self.height_emb = nn.Embedding(self.height, embed_dim)
+        self.width_emb = nn.Embedding(self.width, embed_dim)
+
+    def forward(self, index):
+        emb = self.emb(index)
+
+        height_emb = self.height_emb(torch.arange(self.height, device=index.device).view(1, self.height))
+
+        # 1 x H x D -> 1 x H x 1 x D
+        height_emb = height_emb.unsqueeze(2)
+
+        width_emb = self.width_emb(torch.arange(self.width, device=index.device).view(1, self.width))
+
+        # 1 x W x D -> 1 x 1 x W x D
+        width_emb = width_emb.unsqueeze(1)
+
+        pos_emb = height_emb + width_emb
+
+        # 1 x H x W x D -> 1 x L xD
+        pos_emb = pos_emb.view(1, self.height * self.width, -1)
+
+        emb = emb + pos_emb[:, : emb.shape[1], :]
+
+        return emb
+
+
+class LabelEmbedding(nn.Module):
+    """
+    Embeds class labels into vector representations. Also handles label dropout for classifier-free guidance.
+
+    Args:
+        num_classes (`int`): The number of classes.
+        hidden_size (`int`): The size of the vector embeddings.
+        dropout_prob (`float`): The probability of dropping a label.
+    """
+
+    def __init__(self, num_classes, hidden_size, dropout_prob):
+        super().__init__()
+        use_cfg_embedding = dropout_prob > 0
+        self.embedding_table = nn.Embedding(num_classes + use_cfg_embedding, hidden_size)
+        self.num_classes = num_classes
+        self.dropout_prob = dropout_prob
+
+    def token_drop(self, labels, force_drop_ids=None):
+        """
+        Drops labels to enable classifier-free guidance.
+        """
+        if force_drop_ids is None:
+            drop_ids = torch.rand(labels.shape[0], device=labels.device) < self.dropout_prob
+        else:
+            drop_ids = torch.tensor(force_drop_ids == 1)
+        labels = torch.where(drop_ids, self.num_classes, labels)
+        return labels
+
+    def forward(self, labels: torch.LongTensor, force_drop_ids=None):
+        use_dropout = self.dropout_prob > 0
+        if (self.training and use_dropout) or (force_drop_ids is not None):
+            labels = self.token_drop(labels, force_drop_ids)
+        embeddings = self.embedding_table(labels)
+        return embeddings
+
+
+class TextImageProjection(nn.Module):
+    def __init__(
+        self,
+        text_embed_dim: int = 1024,
+        image_embed_dim: int = 768,
+        cross_attention_dim: int = 768,
+        num_image_text_embeds: int = 10,
+    ):
+        super().__init__()
+
+        self.num_image_text_embeds = num_image_text_embeds
+        self.image_embeds = nn.Linear(image_embed_dim, self.num_image_text_embeds * cross_attention_dim)
+        self.text_proj = nn.Linear(text_embed_dim, cross_attention_dim)
+
+    def forward(self, text_embeds: torch.FloatTensor, image_embeds: torch.FloatTensor):
+        batch_size = text_embeds.shape[0]
+
+        # image
+        image_text_embeds = self.image_embeds(image_embeds)
+        image_text_embeds = image_text_embeds.reshape(batch_size, self.num_image_text_embeds, -1)
+
+        # text
+        text_embeds = self.text_proj(text_embeds)
+
+        return torch.cat([image_text_embeds, text_embeds], dim=1)
+
+
+class ImageProjection(nn.Module):
+    def __init__(
+        self,
+        image_embed_dim: int = 768,
+        cross_attention_dim: int = 768,
+        num_image_text_embeds: int = 32,
+    ):
+        super().__init__()
+
+        self.num_image_text_embeds = num_image_text_embeds
+        self.image_embeds = nn.Linear(image_embed_dim, self.num_image_text_embeds * cross_attention_dim)
+        self.norm = nn.LayerNorm(cross_attention_dim)
+
+    def forward(self, image_embeds: torch.FloatTensor):
+        batch_size = image_embeds.shape[0]
+
+        # image
+        image_embeds = self.image_embeds(image_embeds)
+        image_embeds = image_embeds.reshape(batch_size, self.num_image_text_embeds, -1)
+        image_embeds = self.norm(image_embeds)
+        return image_embeds
+
+
+class IPAdapterFullImageProjection(nn.Module):
+    def __init__(self, image_embed_dim=1024, cross_attention_dim=1024):
+        super().__init__()
+        from .attention import FeedForward
+
+        self.ff = FeedForward(image_embed_dim, cross_attention_dim, mult=1, activation_fn="gelu")
+        self.norm = nn.LayerNorm(cross_attention_dim)
+
+    def forward(self, image_embeds: torch.FloatTensor):
+        return self.norm(self.ff(image_embeds))
+
+
+class CombinedTimestepLabelEmbeddings(nn.Module):
+    def __init__(self, num_classes, embedding_dim, class_dropout_prob=0.1):
+        super().__init__()
+
+        self.time_proj = Timesteps(num_channels=256, flip_sin_to_cos=True, downscale_freq_shift=1)
+        self.timestep_embedder = TimestepEmbedding(in_channels=256, time_embed_dim=embedding_dim)
+        self.class_embedder = LabelEmbedding(num_classes, embedding_dim, class_dropout_prob)
+
+    def forward(self, timestep, class_labels, hidden_dtype=None):
+        timesteps_proj = self.time_proj(timestep)
+        timesteps_emb = self.timestep_embedder(timesteps_proj.to(dtype=hidden_dtype))  # (N, D)
+
+        class_labels = self.class_embedder(class_labels)  # (N, D)
+
+        conditioning = timesteps_emb + class_labels  # (N, D)
+
+        return conditioning
+
+
+class TextTimeEmbedding(nn.Module):
+    def __init__(self, encoder_dim: int, time_embed_dim: int, num_heads: int = 64):
+        super().__init__()
+        self.norm1 = nn.LayerNorm(encoder_dim)
+        self.pool = AttentionPooling(num_heads, encoder_dim)
+        self.proj = nn.Linear(encoder_dim, time_embed_dim)
+        self.norm2 = nn.LayerNorm(time_embed_dim)
+
+    def forward(self, hidden_states):
+        hidden_states = self.norm1(hidden_states)
+        hidden_states = self.pool(hidden_states)
+        hidden_states = self.proj(hidden_states)
+        hidden_states = self.norm2(hidden_states)
+        return hidden_states
+
+
+class TextImageTimeEmbedding(nn.Module):
+    def __init__(self, text_embed_dim: int = 768, image_embed_dim: int = 768, time_embed_dim: int = 1536):
+        super().__init__()
+        self.text_proj = nn.Linear(text_embed_dim, time_embed_dim)
+        self.text_norm = nn.LayerNorm(time_embed_dim)
+        self.image_proj = nn.Linear(image_embed_dim, time_embed_dim)
+
+    def forward(self, text_embeds: torch.FloatTensor, image_embeds: torch.FloatTensor):
+        # text
+        time_text_embeds = self.text_proj(text_embeds)
+        time_text_embeds = self.text_norm(time_text_embeds)
+
+        # image
+        time_image_embeds = self.image_proj(image_embeds)
+
+        return time_image_embeds + time_text_embeds
+
+
+class ImageTimeEmbedding(nn.Module):
+    def __init__(self, image_embed_dim: int = 768, time_embed_dim: int = 1536):
+        super().__init__()
+        self.image_proj = nn.Linear(image_embed_dim, time_embed_dim)
+        self.image_norm = nn.LayerNorm(time_embed_dim)
+
+    def forward(self, image_embeds: torch.FloatTensor):
+        # image
+        time_image_embeds = self.image_proj(image_embeds)
+        time_image_embeds = self.image_norm(time_image_embeds)
+        return time_image_embeds
+
+
+class ImageHintTimeEmbedding(nn.Module):
+    def __init__(self, image_embed_dim: int = 768, time_embed_dim: int = 1536):
+        super().__init__()
+        self.image_proj = nn.Linear(image_embed_dim, time_embed_dim)
+        self.image_norm = nn.LayerNorm(time_embed_dim)
+        self.input_hint_block = nn.Sequential(
+            nn.Conv2d(3, 16, 3, padding=1),
+            nn.SiLU(),
+            nn.Conv2d(16, 16, 3, padding=1),
+            nn.SiLU(),
+            nn.Conv2d(16, 32, 3, padding=1, stride=2),
+            nn.SiLU(),
+            nn.Conv2d(32, 32, 3, padding=1),
+            nn.SiLU(),
+            nn.Conv2d(32, 96, 3, padding=1, stride=2),
+            nn.SiLU(),
+            nn.Conv2d(96, 96, 3, padding=1),
+            nn.SiLU(),
+            nn.Conv2d(96, 256, 3, padding=1, stride=2),
+            nn.SiLU(),
+            nn.Conv2d(256, 4, 3, padding=1),
+        )
+
+    def forward(self, image_embeds: torch.FloatTensor, hint: torch.FloatTensor):
+        # image
+        time_image_embeds = self.image_proj(image_embeds)
+        time_image_embeds = self.image_norm(time_image_embeds)
+        hint = self.input_hint_block(hint)
+        return time_image_embeds, hint
+
+
+class AttentionPooling(nn.Module):
+    # Copied from https://github.com/deep-floyd/IF/blob/2f91391f27dd3c468bf174be5805b4cc92980c0b/deepfloyd_if/model/nn.py#L54
+
+    def __init__(self, num_heads, embed_dim, dtype=None):
+        super().__init__()
+        self.dtype = dtype
+        self.positional_embedding = nn.Parameter(torch.randn(1, embed_dim) / embed_dim**0.5)
+        self.k_proj = nn.Linear(embed_dim, embed_dim, dtype=self.dtype)
+        self.q_proj = nn.Linear(embed_dim, embed_dim, dtype=self.dtype)
+        self.v_proj = nn.Linear(embed_dim, embed_dim, dtype=self.dtype)
+        self.num_heads = num_heads
+        self.dim_per_head = embed_dim // self.num_heads
+
+    def forward(self, x):
+        bs, length, width = x.size()
+
+        def shape(x):
+            # (bs, length, width) --> (bs, length, n_heads, dim_per_head)
+            x = x.view(bs, -1, self.num_heads, self.dim_per_head)
+            # (bs, length, n_heads, dim_per_head) --> (bs, n_heads, length, dim_per_head)
+            x = x.transpose(1, 2)
+            # (bs, n_heads, length, dim_per_head) --> (bs*n_heads, length, dim_per_head)
+            x = x.reshape(bs * self.num_heads, -1, self.dim_per_head)
+            # (bs*n_heads, length, dim_per_head) --> (bs*n_heads, dim_per_head, length)
+            x = x.transpose(1, 2)
+            return x
+
+        class_token = x.mean(dim=1, keepdim=True) + self.positional_embedding.to(x.dtype)
+        x = torch.cat([class_token, x], dim=1)  # (bs, length+1, width)
+
+        # (bs*n_heads, class_token_length, dim_per_head)
+        q = shape(self.q_proj(class_token))
+        # (bs*n_heads, length+class_token_length, dim_per_head)
+        k = shape(self.k_proj(x))
+        v = shape(self.v_proj(x))
+
+        # (bs*n_heads, class_token_length, length+class_token_length):
+        scale = 1 / math.sqrt(math.sqrt(self.dim_per_head))
+        weight = torch.einsum("bct,bcs->bts", q * scale, k * scale)  # More stable with f16 than dividing afterwards
+        weight = torch.softmax(weight.float(), dim=-1).type(weight.dtype)
+
+        # (bs*n_heads, dim_per_head, class_token_length)
+        a = torch.einsum("bts,bcs->bct", weight, v)
+
+        # (bs, length+1, width)
+        a = a.reshape(bs, -1, 1).transpose(1, 2)
+
+        return a[:, 0, :]  # cls_token
+
+
+def get_fourier_embeds_from_boundingbox(embed_dim, box):
+    """
+    Args:
+        embed_dim: int
+        box: a 3-D tensor [B x N x 4] representing the bounding boxes for GLIGEN pipeline
+    Returns:
+        [B x N x embed_dim] tensor of positional embeddings
+    """
+
+    batch_size, num_boxes = box.shape[:2]
+
+    emb = 100 ** (torch.arange(embed_dim) / embed_dim)
+    emb = emb[None, None, None].to(device=box.device, dtype=box.dtype)
+    emb = emb * box.unsqueeze(-1)
+
+    emb = torch.stack((emb.sin(), emb.cos()), dim=-1)
+    emb = emb.permute(0, 1, 3, 4, 2).reshape(batch_size, num_boxes, embed_dim * 2 * 4)
+
+    return emb
+
+
+class GLIGENTextBoundingboxProjection(nn.Module):
+    def __init__(self, positive_len, out_dim, feature_type="text-only", fourier_freqs=8):
+        super().__init__()
+        self.positive_len = positive_len
+        self.out_dim = out_dim
+
+        self.fourier_embedder_dim = fourier_freqs
+        self.position_dim = fourier_freqs * 2 * 4  # 2: sin/cos, 4: xyxy
+
+        if isinstance(out_dim, tuple):
+            out_dim = out_dim[0]
+
+        if feature_type == "text-only":
+            self.linears = nn.Sequential(
+                nn.Linear(self.positive_len + self.position_dim, 512),
+                nn.SiLU(),
+                nn.Linear(512, 512),
+                nn.SiLU(),
+                nn.Linear(512, out_dim),
+            )
+            self.null_positive_feature = torch.nn.Parameter(torch.zeros([self.positive_len]))
+
+        elif feature_type == "text-image":
+            self.linears_text = nn.Sequential(
+                nn.Linear(self.positive_len + self.position_dim, 512),
+                nn.SiLU(),
+                nn.Linear(512, 512),
+                nn.SiLU(),
+                nn.Linear(512, out_dim),
+            )
+            self.linears_image = nn.Sequential(
+                nn.Linear(self.positive_len + self.position_dim, 512),
+                nn.SiLU(),
+                nn.Linear(512, 512),
+                nn.SiLU(),
+                nn.Linear(512, out_dim),
+            )
+            self.null_text_feature = torch.nn.Parameter(torch.zeros([self.positive_len]))
+            self.null_image_feature = torch.nn.Parameter(torch.zeros([self.positive_len]))
+
+        self.null_position_feature = torch.nn.Parameter(torch.zeros([self.position_dim]))
+
+    def forward(
+        self,
+        boxes,
+        masks,
+        positive_embeddings=None,
+        phrases_masks=None,
+        image_masks=None,
+        phrases_embeddings=None,
+        image_embeddings=None,
+    ):
+        masks = masks.unsqueeze(-1)
+
+        # embedding position (it may includes padding as placeholder)
+        xyxy_embedding = get_fourier_embeds_from_boundingbox(self.fourier_embedder_dim, boxes)  # B*N*4 -> B*N*C
+
+        # learnable null embedding
+        xyxy_null = self.null_position_feature.view(1, 1, -1)
+
+        # replace padding with learnable null embedding
+        xyxy_embedding = xyxy_embedding * masks + (1 - masks) * xyxy_null
+
+        # positionet with text only information
+        if positive_embeddings is not None:
+            # learnable null embedding
+            positive_null = self.null_positive_feature.view(1, 1, -1)
+
+            # replace padding with learnable null embedding
+            positive_embeddings = positive_embeddings * masks + (1 - masks) * positive_null
+
+            objs = self.linears(torch.cat([positive_embeddings, xyxy_embedding], dim=-1))
+
+        # positionet with text and image infomation
+        else:
+            phrases_masks = phrases_masks.unsqueeze(-1)
+            image_masks = image_masks.unsqueeze(-1)
+
+            # learnable null embedding
+            text_null = self.null_text_feature.view(1, 1, -1)
+            image_null = self.null_image_feature.view(1, 1, -1)
+
+            # replace padding with learnable null embedding
+            phrases_embeddings = phrases_embeddings * phrases_masks + (1 - phrases_masks) * text_null
+            image_embeddings = image_embeddings * image_masks + (1 - image_masks) * image_null
+
+            objs_text = self.linears_text(torch.cat([phrases_embeddings, xyxy_embedding], dim=-1))
+            objs_image = self.linears_image(torch.cat([image_embeddings, xyxy_embedding], dim=-1))
+            objs = torch.cat([objs_text, objs_image], dim=1)
+
+        return objs
+
+
+class PixArtAlphaCombinedTimestepSizeEmbeddings(nn.Module):
+    """
+    For PixArt-Alpha.
+
+    Reference:
+    https://github.com/PixArt-alpha/PixArt-alpha/blob/0f55e922376d8b797edd44d25d0e7464b260dcab/diffusion/model/nets/PixArtMS.py#L164C9-L168C29
+    """
+
+    def __init__(self, embedding_dim, size_emb_dim, use_additional_conditions: bool = False):
+        super().__init__()
+
+        self.outdim = size_emb_dim
+        self.time_proj = Timesteps(num_channels=256, flip_sin_to_cos=True, downscale_freq_shift=0)
+        self.timestep_embedder = TimestepEmbedding(in_channels=256, time_embed_dim=embedding_dim)
+
+        self.use_additional_conditions = use_additional_conditions
+        if use_additional_conditions:
+            self.additional_condition_proj = Timesteps(num_channels=256, flip_sin_to_cos=True, downscale_freq_shift=0)
+            self.resolution_embedder = TimestepEmbedding(in_channels=256, time_embed_dim=size_emb_dim)
+            self.aspect_ratio_embedder = TimestepEmbedding(in_channels=256, time_embed_dim=size_emb_dim)
+
+    def forward(self, timestep, resolution, aspect_ratio, batch_size, hidden_dtype):
+        timesteps_proj = self.time_proj(timestep)
+        timesteps_emb = self.timestep_embedder(timesteps_proj.to(dtype=hidden_dtype))  # (N, D)
+
+        if self.use_additional_conditions:
+            resolution_emb = self.additional_condition_proj(resolution.flatten()).to(hidden_dtype)
+            resolution_emb = self.resolution_embedder(resolution_emb).reshape(batch_size, -1)
+            aspect_ratio_emb = self.additional_condition_proj(aspect_ratio.flatten()).to(hidden_dtype)
+            aspect_ratio_emb = self.aspect_ratio_embedder(aspect_ratio_emb).reshape(batch_size, -1)
+            conditioning = timesteps_emb + torch.cat([resolution_emb, aspect_ratio_emb], dim=1)
+        else:
+            conditioning = timesteps_emb
+
+        return conditioning
+
+
+class PixArtAlphaTextProjection(nn.Module):
+    """
+    Projects caption embeddings. Also handles dropout for classifier-free guidance.
+
+    Adapted from https://github.com/PixArt-alpha/PixArt-alpha/blob/master/diffusion/model/nets/PixArt_blocks.py
+    """
+
+    def __init__(self, in_features, hidden_size, num_tokens=120):
+        super().__init__()
+        self.linear_1 = nn.Linear(in_features=in_features, out_features=hidden_size, bias=True)
+        self.act_1 = nn.GELU(approximate="tanh")
+        self.linear_2 = nn.Linear(in_features=hidden_size, out_features=hidden_size, bias=True)
+
+    def forward(self, caption):
+        hidden_states = self.linear_1(caption)
+        hidden_states = self.act_1(hidden_states)
+        hidden_states = self.linear_2(hidden_states)
+        return hidden_states
+
+
+class IPAdapterPlusImageProjection(nn.Module):
+    """Resampler of IP-Adapter Plus.
+
+    Args:
+    ----
+        embed_dims (int): The feature dimension. Defaults to 768.
+        output_dims (int): The number of output channels, that is the same
+            number of the channels in the
+            `unet.config.cross_attention_dim`. Defaults to 1024.
+        hidden_dims (int): The number of hidden channels. Defaults to 1280.
+        depth (int): The number of blocks. Defaults to 8.
+        dim_head (int): The number of head channels. Defaults to 64.
+        heads (int): Parallel attention heads. Defaults to 16.
+        num_queries (int): The number of queries. Defaults to 8.
+        ffn_ratio (float): The expansion ratio of feedforward network hidden
+            layer channels. Defaults to 4.
+    """
+
+    def __init__(
+        self,
+        embed_dims: int = 768,
+        output_dims: int = 1024,
+        hidden_dims: int = 1280,
+        depth: int = 4,
+        dim_head: int = 64,
+        heads: int = 16,
+        num_queries: int = 8,
+        ffn_ratio: float = 4,
+    ) -> None:
+        super().__init__()
+        from .attention import FeedForward  # Lazy import to avoid circular import
+
+        self.latents = nn.Parameter(torch.randn(1, num_queries, hidden_dims) / hidden_dims**0.5)
+
+        self.proj_in = nn.Linear(embed_dims, hidden_dims)
+
+        self.proj_out = nn.Linear(hidden_dims, output_dims)
+        self.norm_out = nn.LayerNorm(output_dims)
+
+        self.layers = nn.ModuleList([])
+        for _ in range(depth):
+            self.layers.append(
+                nn.ModuleList(
+                    [
+                        nn.LayerNorm(hidden_dims),
+                        nn.LayerNorm(hidden_dims),
+                        Attention(
+                            query_dim=hidden_dims,
+                            dim_head=dim_head,
+                            heads=heads,
+                            out_bias=False,
+                        ),
+                        nn.Sequential(
+                            nn.LayerNorm(hidden_dims),
+                            FeedForward(hidden_dims, hidden_dims, activation_fn="gelu", mult=ffn_ratio, bias=False),
+                        ),
+                    ]
+                )
+            )
+
+    def forward(self, x: torch.Tensor) -> torch.Tensor:
+        """Forward pass.
+
+        Args:
+        ----
+            x (torch.Tensor): Input Tensor.
+
+        Returns:
+        -------
+            torch.Tensor: Output Tensor.
+        """
+        latents = self.latents.repeat(x.size(0), 1, 1)
+
+        x = self.proj_in(x)
+
+        for ln0, ln1, attn, ff in self.layers:
+            residual = latents
+
+            encoder_hidden_states = ln0(x)
+            latents = ln1(latents)
+            encoder_hidden_states = torch.cat([encoder_hidden_states, latents], dim=-2)
+            latents = attn(latents, encoder_hidden_states) + residual
+            latents = ff(latents) + latents
+
+        latents = self.proj_out(latents)
+        return self.norm_out(latents)
+
+
+class MultiIPAdapterImageProjection(nn.Module):
+    def __init__(self, IPAdapterImageProjectionLayers: Union[List[nn.Module], Tuple[nn.Module]]):
+        super().__init__()
+        self.image_projection_layers = nn.ModuleList(IPAdapterImageProjectionLayers)
+
+    def forward(self, image_embeds: List[torch.FloatTensor]):
+        projected_image_embeds = []
+
+        # currently, we accept `image_embeds` as
+        #  1. a tensor (deprecated) with shape [batch_size, embed_dim] or [batch_size, sequence_length, embed_dim]
+        #  2. list of `n` tensors where `n` is number of ip-adapters, each tensor can hae shape [batch_size, num_images, embed_dim] or [batch_size, num_images, sequence_length, embed_dim]
+        if not isinstance(image_embeds, list):
+            deprecation_message = (
+                "You have passed a tensor as `image_embeds`.This is deprecated and will be removed in a future release."
+                " Please make sure to update your script to pass `image_embeds` as a list of tensors to supress this warning."
+            )
+            deprecate("image_embeds not a list", "1.0.0", deprecation_message, standard_warn=False)
+            image_embeds = [image_embeds.unsqueeze(1)]
+
+        if len(image_embeds) != len(self.image_projection_layers):
+            raise ValueError(
+                f"image_embeds must have the same length as image_projection_layers, got {len(image_embeds)} and {len(self.image_projection_layers)}"
+            )
+
+        for image_embed, image_projection_layer in zip(image_embeds, self.image_projection_layers):
+            batch_size, num_images = image_embed.shape[0], image_embed.shape[1]
+            image_embed = image_embed.reshape((batch_size * num_images,) + image_embed.shape[2:])
+            image_embed = image_projection_layer(image_embed)
+            image_embed = image_embed.reshape((batch_size, num_images) + image_embed.shape[1:])
+
+            projected_image_embeds.append(image_embed)
+
+        return projected_image_embeds

diffusers-0.27.0/src/diffusers/models/embeddings_flax.py

+# Copyright 2024 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.
+import math
+
+import flax.linen as nn
+import jax.numpy as jnp
+
+
+def get_sinusoidal_embeddings(
+    timesteps: jnp.ndarray,
+    embedding_dim: int,
+    freq_shift: float = 1,
+    min_timescale: float = 1,
+    max_timescale: float = 1.0e4,
+    flip_sin_to_cos: bool = False,
+    scale: float = 1.0,
+) -> jnp.ndarray:
+    """Returns the positional encoding (same as Tensor2Tensor).
+
+    Args:
+        timesteps: a 1-D Tensor of N indices, one per batch element.
+        These may be fractional.
+        embedding_dim: The number of output channels.
+        min_timescale: The smallest time unit (should probably be 0.0).
+        max_timescale: The largest time unit.
+    Returns:
+        a Tensor of timing signals [N, num_channels]
+    """
+    assert timesteps.ndim == 1, "Timesteps should be a 1d-array"
+    assert embedding_dim % 2 == 0, f"Embedding dimension {embedding_dim} should be even"
+    num_timescales = float(embedding_dim // 2)
+    log_timescale_increment = math.log(max_timescale / min_timescale) / (num_timescales - freq_shift)
+    inv_timescales = min_timescale * jnp.exp(jnp.arange(num_timescales, dtype=jnp.float32) * -log_timescale_increment)
+    emb = jnp.expand_dims(timesteps, 1) * jnp.expand_dims(inv_timescales, 0)
+
+    # scale embeddings
+    scaled_time = scale * emb
+
+    if flip_sin_to_cos:
+        signal = jnp.concatenate([jnp.cos(scaled_time), jnp.sin(scaled_time)], axis=1)
+    else:
+        signal = jnp.concatenate([jnp.sin(scaled_time), jnp.cos(scaled_time)], axis=1)
+    signal = jnp.reshape(signal, [jnp.shape(timesteps)[0], embedding_dim])
+    return signal
+
+
+class FlaxTimestepEmbedding(nn.Module):
+    r"""
+    Time step Embedding Module. Learns embeddings for input time steps.
+
+    Args:
+        time_embed_dim (`int`, *optional*, defaults to `32`):
+                Time step embedding dimension
+        dtype (:obj:`jnp.dtype`, *optional*, defaults to jnp.float32):
+                Parameters `dtype`
+    """
+
+    time_embed_dim: int = 32
+    dtype: jnp.dtype = jnp.float32
+
+    @nn.compact
+    def __call__(self, temb):
+        temb = nn.Dense(self.time_embed_dim, dtype=self.dtype, name="linear_1")(temb)
+        temb = nn.silu(temb)
+        temb = nn.Dense(self.time_embed_dim, dtype=self.dtype, name="linear_2")(temb)
+        return temb
+
+
+class FlaxTimesteps(nn.Module):
+    r"""
+    Wrapper Module for sinusoidal Time step Embeddings as described in https://arxiv.org/abs/2006.11239
+
+    Args:
+        dim (`int`, *optional*, defaults to `32`):
+                Time step embedding dimension
+    """
+
+    dim: int = 32
+    flip_sin_to_cos: bool = False
+    freq_shift: float = 1
+
+    @nn.compact
+    def __call__(self, timesteps):
+        return get_sinusoidal_embeddings(
+            timesteps, embedding_dim=self.dim, flip_sin_to_cos=self.flip_sin_to_cos, freq_shift=self.freq_shift
+        )

diffusers-0.27.0/src/diffusers/models/lora.py

+# Copyright 2024 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.
+
+
+# IMPORTANT:                                                      #
+###################################################################
+# ----------------------------------------------------------------#
+# This file is deprecated and will be removed soon                #
+# (as soon as PEFT will become a required dependency for LoRA)    #
+# ----------------------------------------------------------------#
+###################################################################
+
+from typing import Optional, Tuple, Union
+
+import torch
+import torch.nn.functional as F
+from torch import nn
+
+from ..utils import deprecate, logging
+from ..utils.import_utils import is_transformers_available
+
+
+if is_transformers_available():
+    from transformers import CLIPTextModel, CLIPTextModelWithProjection
+
+
+logger = logging.get_logger(__name__)  # pylint: disable=invalid-name
+
+
+def text_encoder_attn_modules(text_encoder):
+    attn_modules = []
+
+    if isinstance(text_encoder, (CLIPTextModel, CLIPTextModelWithProjection)):
+        for i, layer in enumerate(text_encoder.text_model.encoder.layers):
+            name = f"text_model.encoder.layers.{i}.self_attn"
+            mod = layer.self_attn
+            attn_modules.append((name, mod))
+    else:
+        raise ValueError(f"do not know how to get attention modules for: {text_encoder.__class__.__name__}")
+
+    return attn_modules
+
+
+def text_encoder_mlp_modules(text_encoder):
+    mlp_modules = []
+
+    if isinstance(text_encoder, (CLIPTextModel, CLIPTextModelWithProjection)):
+        for i, layer in enumerate(text_encoder.text_model.encoder.layers):
+            mlp_mod = layer.mlp
+            name = f"text_model.encoder.layers.{i}.mlp"
+            mlp_modules.append((name, mlp_mod))
+    else:
+        raise ValueError(f"do not know how to get mlp modules for: {text_encoder.__class__.__name__}")
+
+    return mlp_modules
+
+
+def adjust_lora_scale_text_encoder(text_encoder, lora_scale: float = 1.0):
+    for _, attn_module in text_encoder_attn_modules(text_encoder):
+        if isinstance(attn_module.q_proj, PatchedLoraProjection):
+            attn_module.q_proj.lora_scale = lora_scale
+            attn_module.k_proj.lora_scale = lora_scale
+            attn_module.v_proj.lora_scale = lora_scale
+            attn_module.out_proj.lora_scale = lora_scale
+
+    for _, mlp_module in text_encoder_mlp_modules(text_encoder):
+        if isinstance(mlp_module.fc1, PatchedLoraProjection):
+            mlp_module.fc1.lora_scale = lora_scale
+            mlp_module.fc2.lora_scale = lora_scale
+
+
+class PatchedLoraProjection(torch.nn.Module):
+    def __init__(self, regular_linear_layer, lora_scale=1, network_alpha=None, rank=4, dtype=None):
+        deprecation_message = "Use of `PatchedLoraProjection` is deprecated. Please switch to PEFT backend by installing PEFT: `pip install peft`."
+        deprecate("PatchedLoraProjection", "1.0.0", deprecation_message)
+
+        super().__init__()
+        from ..models.lora import LoRALinearLayer
+
+        self.regular_linear_layer = regular_linear_layer
+
+        device = self.regular_linear_layer.weight.device
+
+        if dtype is None:
+            dtype = self.regular_linear_layer.weight.dtype
+
+        self.lora_linear_layer = LoRALinearLayer(
+            self.regular_linear_layer.in_features,
+            self.regular_linear_layer.out_features,
+            network_alpha=network_alpha,
+            device=device,
+            dtype=dtype,
+            rank=rank,
+        )
+
+        self.lora_scale = lora_scale
+
+    # overwrite PyTorch's `state_dict` to be sure that only the 'regular_linear_layer' weights are saved
+    # when saving the whole text encoder model and when LoRA is unloaded or fused
+    def state_dict(self, *args, destination=None, prefix="", keep_vars=False):
+        if self.lora_linear_layer is None:
+            return self.regular_linear_layer.state_dict(
+                *args, destination=destination, prefix=prefix, keep_vars=keep_vars
+            )
+
+        return super().state_dict(*args, destination=destination, prefix=prefix, keep_vars=keep_vars)
+
+    def _fuse_lora(self, lora_scale=1.0, safe_fusing=False):
+        if self.lora_linear_layer is None:
+            return
+
+        dtype, device = self.regular_linear_layer.weight.data.dtype, self.regular_linear_layer.weight.data.device
+
+        w_orig = self.regular_linear_layer.weight.data.float()
+        w_up = self.lora_linear_layer.up.weight.data.float()
+        w_down = self.lora_linear_layer.down.weight.data.float()
+
+        if self.lora_linear_layer.network_alpha is not None:
+            w_up = w_up * self.lora_linear_layer.network_alpha / self.lora_linear_layer.rank
+
+        fused_weight = w_orig + (lora_scale * torch.bmm(w_up[None, :], w_down[None, :])[0])
+
+        if safe_fusing and torch.isnan(fused_weight).any().item():
+            raise ValueError(
+                "This LoRA weight seems to be broken. "
+                f"Encountered NaN values when trying to fuse LoRA weights for {self}."
+                "LoRA weights will not be fused."
+            )
+
+        self.regular_linear_layer.weight.data = fused_weight.to(device=device, dtype=dtype)
+
+        # we can drop the lora layer now
+        self.lora_linear_layer = None
+
+        # offload the up and down matrices to CPU to not blow the memory
+        self.w_up = w_up.cpu()
+        self.w_down = w_down.cpu()
+        self.lora_scale = lora_scale
+
+    def _unfuse_lora(self):
+        if not (getattr(self, "w_up", None) is not None and getattr(self, "w_down", None) is not None):
+            return
+
+        fused_weight = self.regular_linear_layer.weight.data
+        dtype, device = fused_weight.dtype, fused_weight.device
+
+        w_up = self.w_up.to(device=device).float()
+        w_down = self.w_down.to(device).float()
+
+        unfused_weight = fused_weight.float() - (self.lora_scale * torch.bmm(w_up[None, :], w_down[None, :])[0])
+        self.regular_linear_layer.weight.data = unfused_weight.to(device=device, dtype=dtype)
+
+        self.w_up = None
+        self.w_down = None
+
+    def forward(self, input):
+        if self.lora_scale is None:
+            self.lora_scale = 1.0
+        if self.lora_linear_layer is None:
+            return self.regular_linear_layer(input)
+        return self.regular_linear_layer(input) + (self.lora_scale * self.lora_linear_layer(input))
+
+
+class LoRALinearLayer(nn.Module):
+    r"""
+    A linear layer that is used with LoRA.
+
+    Parameters:
+        in_features (`int`):
+            Number of input features.
+        out_features (`int`):
+            Number of output features.
+        rank (`int`, `optional`, defaults to 4):
+            The rank of the LoRA layer.
+        network_alpha (`float`, `optional`, defaults to `None`):
+            The value of the network alpha used for stable learning and preventing underflow. This value has the same
+            meaning as the `--network_alpha` option in the kohya-ss trainer script. See
+            https://github.com/darkstorm2150/sd-scripts/blob/main/docs/train_network_README-en.md#execute-learning
+        device (`torch.device`, `optional`, defaults to `None`):
+            The device to use for the layer's weights.
+        dtype (`torch.dtype`, `optional`, defaults to `None`):
+            The dtype to use for the layer's weights.
+    """
+
+    def __init__(
+        self,
+        in_features: int,
+        out_features: int,
+        rank: int = 4,
+        network_alpha: Optional[float] = None,
+        device: Optional[Union[torch.device, str]] = None,
+        dtype: Optional[torch.dtype] = None,
+    ):
+        super().__init__()
+
+        deprecation_message = "Use of `LoRALinearLayer` is deprecated. Please switch to PEFT backend by installing PEFT: `pip install peft`."
+        deprecate("LoRALinearLayer", "1.0.0", deprecation_message)
+
+        self.down = nn.Linear(in_features, rank, bias=False, device=device, dtype=dtype)
+        self.up = nn.Linear(rank, out_features, bias=False, device=device, dtype=dtype)
+        # This value has the same meaning as the `--network_alpha` option in the kohya-ss trainer script.
+        # See https://github.com/darkstorm2150/sd-scripts/blob/main/docs/train_network_README-en.md#execute-learning
+        self.network_alpha = network_alpha
+        self.rank = rank
+        self.out_features = out_features
+        self.in_features = in_features
+
+        nn.init.normal_(self.down.weight, std=1 / rank)
+        nn.init.zeros_(self.up.weight)
+
+    def forward(self, hidden_states: torch.Tensor) -> torch.Tensor:
+        orig_dtype = hidden_states.dtype
+        dtype = self.down.weight.dtype
+
+        down_hidden_states = self.down(hidden_states.to(dtype))
+        up_hidden_states = self.up(down_hidden_states)
+
+        if self.network_alpha is not None:
+            up_hidden_states *= self.network_alpha / self.rank
+
+        return up_hidden_states.to(orig_dtype)
+
+
+class LoRAConv2dLayer(nn.Module):
+    r"""
+    A convolutional layer that is used with LoRA.
+
+    Parameters:
+        in_features (`int`):
+            Number of input features.
+        out_features (`int`):
+            Number of output features.
+        rank (`int`, `optional`, defaults to 4):
+            The rank of the LoRA layer.
+        kernel_size (`int` or `tuple` of two `int`, `optional`, defaults to 1):
+            The kernel size of the convolution.
+        stride (`int` or `tuple` of two `int`, `optional`, defaults to 1):
+            The stride of the convolution.
+        padding (`int` or `tuple` of two `int` or `str`, `optional`, defaults to 0):
+            The padding of the convolution.
+        network_alpha (`float`, `optional`, defaults to `None`):
+            The value of the network alpha used for stable learning and preventing underflow. This value has the same
+            meaning as the `--network_alpha` option in the kohya-ss trainer script. See
+            https://github.com/darkstorm2150/sd-scripts/blob/main/docs/train_network_README-en.md#execute-learning
+    """
+
+    def __init__(
+        self,
+        in_features: int,
+        out_features: int,
+        rank: int = 4,
+        kernel_size: Union[int, Tuple[int, int]] = (1, 1),
+        stride: Union[int, Tuple[int, int]] = (1, 1),
+        padding: Union[int, Tuple[int, int], str] = 0,
+        network_alpha: Optional[float] = None,
+    ):
+        super().__init__()
+
+        deprecation_message = "Use of `LoRAConv2dLayer` is deprecated. Please switch to PEFT backend by installing PEFT: `pip install peft`."
+        deprecate("LoRAConv2dLayer", "1.0.0", deprecation_message)
+
+        self.down = nn.Conv2d(in_features, rank, kernel_size=kernel_size, stride=stride, padding=padding, bias=False)
+        # according to the official kohya_ss trainer kernel_size are always fixed for the up layer
+        # # see: https://github.com/bmaltais/kohya_ss/blob/2accb1305979ba62f5077a23aabac23b4c37e935/networks/lora_diffusers.py#L129
+        self.up = nn.Conv2d(rank, out_features, kernel_size=(1, 1), stride=(1, 1), bias=False)
+
+        # This value has the same meaning as the `--network_alpha` option in the kohya-ss trainer script.
+        # See https://github.com/darkstorm2150/sd-scripts/blob/main/docs/train_network_README-en.md#execute-learning
+        self.network_alpha = network_alpha
+        self.rank = rank
+
+        nn.init.normal_(self.down.weight, std=1 / rank)
+        nn.init.zeros_(self.up.weight)
+
+    def forward(self, hidden_states: torch.Tensor) -> torch.Tensor:
+        orig_dtype = hidden_states.dtype
+        dtype = self.down.weight.dtype
+
+        down_hidden_states = self.down(hidden_states.to(dtype))
+        up_hidden_states = self.up(down_hidden_states)
+
+        if self.network_alpha is not None:
+            up_hidden_states *= self.network_alpha / self.rank
+
+        return up_hidden_states.to(orig_dtype)
+
+
+class LoRACompatibleConv(nn.Conv2d):
+    """
+    A convolutional layer that can be used with LoRA.
+    """
+
+    def __init__(self, *args, lora_layer: Optional[LoRAConv2dLayer] = None, **kwargs):
+        deprecation_message = "Use of `LoRACompatibleConv` is deprecated. Please switch to PEFT backend by installing PEFT: `pip install peft`."
+        deprecate("LoRACompatibleConv", "1.0.0", deprecation_message)
+
+        super().__init__(*args, **kwargs)
+        self.lora_layer = lora_layer
+
+    def set_lora_layer(self, lora_layer: Optional[LoRAConv2dLayer]):
+        deprecation_message = "Use of `set_lora_layer()` is deprecated. Please switch to PEFT backend by installing PEFT: `pip install peft`."
+        deprecate("set_lora_layer", "1.0.0", deprecation_message)
+
+        self.lora_layer = lora_layer
+
+    def _fuse_lora(self, lora_scale: float = 1.0, safe_fusing: bool = False):
+        if self.lora_layer is None:
+            return
+
+        dtype, device = self.weight.data.dtype, self.weight.data.device
+
+        w_orig = self.weight.data.float()
+        w_up = self.lora_layer.up.weight.data.float()
+        w_down = self.lora_layer.down.weight.data.float()
+
+        if self.lora_layer.network_alpha is not None:
+            w_up = w_up * self.lora_layer.network_alpha / self.lora_layer.rank
+
+        fusion = torch.mm(w_up.flatten(start_dim=1), w_down.flatten(start_dim=1))
+        fusion = fusion.reshape((w_orig.shape))
+        fused_weight = w_orig + (lora_scale * fusion)
+
+        if safe_fusing and torch.isnan(fused_weight).any().item():
+            raise ValueError(
+                "This LoRA weight seems to be broken. "
+                f"Encountered NaN values when trying to fuse LoRA weights for {self}."
+                "LoRA weights will not be fused."
+            )
+
+        self.weight.data = fused_weight.to(device=device, dtype=dtype)
+
+        # we can drop the lora layer now
+        self.lora_layer = None
+
+        # offload the up and down matrices to CPU to not blow the memory
+        self.w_up = w_up.cpu()
+        self.w_down = w_down.cpu()
+        self._lora_scale = lora_scale
+
+    def _unfuse_lora(self):
+        if not (getattr(self, "w_up", None) is not None and getattr(self, "w_down", None) is not None):
+            return
+
+        fused_weight = self.weight.data
+        dtype, device = fused_weight.data.dtype, fused_weight.data.device
+
+        self.w_up = self.w_up.to(device=device).float()
+        self.w_down = self.w_down.to(device).float()
+
+        fusion = torch.mm(self.w_up.flatten(start_dim=1), self.w_down.flatten(start_dim=1))
+        fusion = fusion.reshape((fused_weight.shape))
+        unfused_weight = fused_weight.float() - (self._lora_scale * fusion)
+        self.weight.data = unfused_weight.to(device=device, dtype=dtype)
+
+        self.w_up = None
+        self.w_down = None
+
+    def forward(self, hidden_states: torch.Tensor, scale: float = 1.0) -> torch.Tensor:
+        if self.padding_mode != "zeros":
+            hidden_states = F.pad(hidden_states, self._reversed_padding_repeated_twice, mode=self.padding_mode)
+            padding = (0, 0)
+        else:
+            padding = self.padding
+
+        original_outputs = F.conv2d(
+            hidden_states, self.weight, self.bias, self.stride, padding, self.dilation, self.groups
+        )
+
+        if self.lora_layer is None:
+            return original_outputs
+        else:
+            return original_outputs + (scale * self.lora_layer(hidden_states))
+
+
+class LoRACompatibleLinear(nn.Linear):
+    """
+    A Linear layer that can be used with LoRA.
+    """
+
+    def __init__(self, *args, lora_layer: Optional[LoRALinearLayer] = None, **kwargs):
+        deprecation_message = "Use of `LoRACompatibleLinear` is deprecated. Please switch to PEFT backend by installing PEFT: `pip install peft`."
+        deprecate("LoRACompatibleLinear", "1.0.0", deprecation_message)
+
+        super().__init__(*args, **kwargs)
+        self.lora_layer = lora_layer
+
+    def set_lora_layer(self, lora_layer: Optional[LoRALinearLayer]):
+        deprecation_message = "Use of `set_lora_layer()` is deprecated. Please switch to PEFT backend by installing PEFT: `pip install peft`."
+        deprecate("set_lora_layer", "1.0.0", deprecation_message)
+        self.lora_layer = lora_layer
+
+    def _fuse_lora(self, lora_scale: float = 1.0, safe_fusing: bool = False):
+        if self.lora_layer is None:
+            return
+
+        dtype, device = self.weight.data.dtype, self.weight.data.device
+
+        w_orig = self.weight.data.float()
+        w_up = self.lora_layer.up.weight.data.float()
+        w_down = self.lora_layer.down.weight.data.float()
+
+        if self.lora_layer.network_alpha is not None:
+            w_up = w_up * self.lora_layer.network_alpha / self.lora_layer.rank
+
+        fused_weight = w_orig + (lora_scale * torch.bmm(w_up[None, :], w_down[None, :])[0])
+
+        if safe_fusing and torch.isnan(fused_weight).any().item():
+            raise ValueError(
+                "This LoRA weight seems to be broken. "
+                f"Encountered NaN values when trying to fuse LoRA weights for {self}."
+                "LoRA weights will not be fused."
+            )
+
+        self.weight.data = fused_weight.to(device=device, dtype=dtype)
+
+        # we can drop the lora layer now
+        self.lora_layer = None
+
+        # offload the up and down matrices to CPU to not blow the memory
+        self.w_up = w_up.cpu()
+        self.w_down = w_down.cpu()
+        self._lora_scale = lora_scale
+
+    def _unfuse_lora(self):
+        if not (getattr(self, "w_up", None) is not None and getattr(self, "w_down", None) is not None):
+            return
+
+        fused_weight = self.weight.data
+        dtype, device = fused_weight.dtype, fused_weight.device
+
+        w_up = self.w_up.to(device=device).float()
+        w_down = self.w_down.to(device).float()
+
+        unfused_weight = fused_weight.float() - (self._lora_scale * torch.bmm(w_up[None, :], w_down[None, :])[0])
+        self.weight.data = unfused_weight.to(device=device, dtype=dtype)
+
+        self.w_up = None
+        self.w_down = None
+
+    def forward(self, hidden_states: torch.Tensor, scale: float = 1.0) -> torch.Tensor:
+        if self.lora_layer is None:
+            out = super().forward(hidden_states)
+            return out
+        else:
+            out = super().forward(hidden_states) + (scale * self.lora_layer(hidden_states))
+            return out

diffusers-0.27.0/src/diffusers/models/modeling_flax_pytorch_utils.py

+# coding=utf-8
+# Copyright 2024 The HuggingFace Inc. team.
+#
+# 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.
+""" PyTorch - Flax general utilities."""
+import re
+
+import jax.numpy as jnp
+from flax.traverse_util import flatten_dict, unflatten_dict
+from jax.random import PRNGKey
+
+from ..utils import logging
+
+
+logger = logging.get_logger(__name__)
+
+
+def rename_key(key):
+    regex = r"\w+[.]\d+"
+    pats = re.findall(regex, key)
+    for pat in pats:
+        key = key.replace(pat, "_".join(pat.split(".")))
+    return key
+
+
+#####################
+# PyTorch => Flax #
+#####################
+
+
+# Adapted from https://github.com/huggingface/transformers/blob/c603c80f46881ae18b2ca50770ef65fa4033eacd/src/transformers/modeling_flax_pytorch_utils.py#L69
+# and https://github.com/patil-suraj/stable-diffusion-jax/blob/main/stable_diffusion_jax/convert_diffusers_to_jax.py
+def rename_key_and_reshape_tensor(pt_tuple_key, pt_tensor, random_flax_state_dict):
+    """Rename PT weight names to corresponding Flax weight names and reshape tensor if necessary"""
+    # conv norm or layer norm
+    renamed_pt_tuple_key = pt_tuple_key[:-1] + ("scale",)
+
+    # rename attention layers
+    if len(pt_tuple_key) > 1:
+        for rename_from, rename_to in (
+            ("to_out_0", "proj_attn"),
+            ("to_k", "key"),
+            ("to_v", "value"),
+            ("to_q", "query"),
+        ):
+            if pt_tuple_key[-2] == rename_from:
+                weight_name = pt_tuple_key[-1]
+                weight_name = "kernel" if weight_name == "weight" else weight_name
+                renamed_pt_tuple_key = pt_tuple_key[:-2] + (rename_to, weight_name)
+                if renamed_pt_tuple_key in random_flax_state_dict:
+                    assert random_flax_state_dict[renamed_pt_tuple_key].shape == pt_tensor.T.shape
+                    return renamed_pt_tuple_key, pt_tensor.T
+
+    if (
+        any("norm" in str_ for str_ in pt_tuple_key)
+        and (pt_tuple_key[-1] == "bias")
+        and (pt_tuple_key[:-1] + ("bias",) not in random_flax_state_dict)
+        and (pt_tuple_key[:-1] + ("scale",) in random_flax_state_dict)
+    ):
+        renamed_pt_tuple_key = pt_tuple_key[:-1] + ("scale",)
+        return renamed_pt_tuple_key, pt_tensor
+    elif pt_tuple_key[-1] in ["weight", "gamma"] and pt_tuple_key[:-1] + ("scale",) in random_flax_state_dict:
+        renamed_pt_tuple_key = pt_tuple_key[:-1] + ("scale",)
+        return renamed_pt_tuple_key, pt_tensor
+
+    # embedding
+    if pt_tuple_key[-1] == "weight" and pt_tuple_key[:-1] + ("embedding",) in random_flax_state_dict:
+        pt_tuple_key = pt_tuple_key[:-1] + ("embedding",)
+        return renamed_pt_tuple_key, pt_tensor
+
+    # conv layer
+    renamed_pt_tuple_key = pt_tuple_key[:-1] + ("kernel",)
+    if pt_tuple_key[-1] == "weight" and pt_tensor.ndim == 4:
+        pt_tensor = pt_tensor.transpose(2, 3, 1, 0)
+        return renamed_pt_tuple_key, pt_tensor
+
+    # linear layer
+    renamed_pt_tuple_key = pt_tuple_key[:-1] + ("kernel",)
+    if pt_tuple_key[-1] == "weight":
+        pt_tensor = pt_tensor.T
+        return renamed_pt_tuple_key, pt_tensor
+
+    # old PyTorch layer norm weight
+    renamed_pt_tuple_key = pt_tuple_key[:-1] + ("weight",)
+    if pt_tuple_key[-1] == "gamma":
+        return renamed_pt_tuple_key, pt_tensor
+
+    # old PyTorch layer norm bias
+    renamed_pt_tuple_key = pt_tuple_key[:-1] + ("bias",)
+    if pt_tuple_key[-1] == "beta":
+        return renamed_pt_tuple_key, pt_tensor
+
+    return pt_tuple_key, pt_tensor
+
+
+def convert_pytorch_state_dict_to_flax(pt_state_dict, flax_model, init_key=42):
+    # Step 1: Convert pytorch tensor to numpy
+    pt_state_dict = {k: v.numpy() for k, v in pt_state_dict.items()}
+
+    # Step 2: Since the model is stateless, get random Flax params
+    random_flax_params = flax_model.init_weights(PRNGKey(init_key))
+
+    random_flax_state_dict = flatten_dict(random_flax_params)
+    flax_state_dict = {}
+
+    # Need to change some parameters name to match Flax names
+    for pt_key, pt_tensor in pt_state_dict.items():
+        renamed_pt_key = rename_key(pt_key)
+        pt_tuple_key = tuple(renamed_pt_key.split("."))
+
+        # Correctly rename weight parameters
+        flax_key, flax_tensor = rename_key_and_reshape_tensor(pt_tuple_key, pt_tensor, random_flax_state_dict)
+
+        if flax_key in random_flax_state_dict:
+            if flax_tensor.shape != random_flax_state_dict[flax_key].shape:
+                raise ValueError(
+                    f"PyTorch checkpoint seems to be incorrect. Weight {pt_key} was expected to be of shape "
+                    f"{random_flax_state_dict[flax_key].shape}, but is {flax_tensor.shape}."
+                )
+
+        # also add unexpected weight so that warning is thrown
+        flax_state_dict[flax_key] = jnp.asarray(flax_tensor)
+
+    return unflatten_dict(flax_state_dict)

diffusers-0.27.0/src/diffusers/models/modeling_flax_utils.py

+# coding=utf-8
+# Copyright 2024 The HuggingFace Inc. team.
+#
+# 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.
+
+import os
+from pickle import UnpicklingError
+from typing import Any, Dict, Union
+
+import jax
+import jax.numpy as jnp
+import msgpack.exceptions
+from flax.core.frozen_dict import FrozenDict, unfreeze
+from flax.serialization import from_bytes, to_bytes
+from flax.traverse_util import flatten_dict, unflatten_dict
+from huggingface_hub import create_repo, hf_hub_download
+from huggingface_hub.utils import (
+    EntryNotFoundError,
+    RepositoryNotFoundError,
+    RevisionNotFoundError,
+    validate_hf_hub_args,
+)
+from requests import HTTPError
+
+from .. import __version__, is_torch_available
+from ..utils import (
+    CONFIG_NAME,
+    FLAX_WEIGHTS_NAME,
+    HUGGINGFACE_CO_RESOLVE_ENDPOINT,
+    WEIGHTS_NAME,
+    PushToHubMixin,
+    logging,
+)
+from .modeling_flax_pytorch_utils import convert_pytorch_state_dict_to_flax
+
+
+logger = logging.get_logger(__name__)
+
+
+class FlaxModelMixin(PushToHubMixin):
+    r"""
+    Base class for all Flax models.
+
+    [`FlaxModelMixin`] takes care of storing the model configuration and provides methods for loading, downloading and
+    saving models.
+
+        - **config_name** ([`str`]) -- Filename to save a model to when calling [`~FlaxModelMixin.save_pretrained`].
+    """
+
+    config_name = CONFIG_NAME
+    _automatically_saved_args = ["_diffusers_version", "_class_name", "_name_or_path"]
+    _flax_internal_args = ["name", "parent", "dtype"]
+
+    @classmethod
+    def _from_config(cls, config, **kwargs):
+        """
+        All context managers that the model should be initialized under go here.
+        """
+        return cls(config, **kwargs)
+
+    def _cast_floating_to(self, params: Union[Dict, FrozenDict], dtype: jnp.dtype, mask: Any = None) -> Any:
+        """
+        Helper method to cast floating-point values of given parameter `PyTree` to given `dtype`.
+        """
+
+        # taken from https://github.com/deepmind/jmp/blob/3a8318abc3292be38582794dbf7b094e6583b192/jmp/_src/policy.py#L27
+        def conditional_cast(param):
+            if isinstance(param, jnp.ndarray) and jnp.issubdtype(param.dtype, jnp.floating):
+                param = param.astype(dtype)
+            return param
+
+        if mask is None:
+            return jax.tree_map(conditional_cast, params)
+
+        flat_params = flatten_dict(params)
+        flat_mask, _ = jax.tree_flatten(mask)
+
+        for masked, key in zip(flat_mask, flat_params.keys()):
+            if masked:
+                param = flat_params[key]
+                flat_params[key] = conditional_cast(param)
+
+        return unflatten_dict(flat_params)
+
+    def to_bf16(self, params: Union[Dict, FrozenDict], mask: Any = None):
+        r"""
+        Cast the floating-point `params` to `jax.numpy.bfloat16`. This returns a new `params` tree and does not cast
+        the `params` in place.
+
+        This method can be used on a TPU to explicitly convert the model parameters to bfloat16 precision to do full
+        half-precision training or to save weights in bfloat16 for inference in order to save memory and improve speed.
+
+        Arguments:
+            params (`Union[Dict, FrozenDict]`):
+                A `PyTree` of model parameters.
+            mask (`Union[Dict, FrozenDict]`):
+                A `PyTree` with same structure as the `params` tree. The leaves should be booleans. It should be `True`
+                for params you want to cast, and `False` for those you want to skip.
+
+        Examples:
+
+        ```python
+        >>> from diffusers import FlaxUNet2DConditionModel
+
+        >>> # load model
+        >>> model, params = FlaxUNet2DConditionModel.from_pretrained("runwayml/stable-diffusion-v1-5")
+        >>> # By default, the model parameters will be in fp32 precision, to cast these to bfloat16 precision
+        >>> params = model.to_bf16(params)
+        >>> # If you don't want to cast certain parameters (for example layer norm bias and scale)
+        >>> # then pass the mask as follows
+        >>> from flax import traverse_util
+
+        >>> model, params = FlaxUNet2DConditionModel.from_pretrained("runwayml/stable-diffusion-v1-5")
+        >>> flat_params = traverse_util.flatten_dict(params)
+        >>> mask = {
+        ...     path: (path[-2] != ("LayerNorm", "bias") and path[-2:] != ("LayerNorm", "scale"))
+        ...     for path in flat_params
+        ... }
+        >>> mask = traverse_util.unflatten_dict(mask)
+        >>> params = model.to_bf16(params, mask)
+        ```"""
+        return self._cast_floating_to(params, jnp.bfloat16, mask)
+
+    def to_fp32(self, params: Union[Dict, FrozenDict], mask: Any = None):
+        r"""
+        Cast the floating-point `params` to `jax.numpy.float32`. This method can be used to explicitly convert the
+        model parameters to fp32 precision. This returns a new `params` tree and does not cast the `params` in place.
+
+        Arguments:
+            params (`Union[Dict, FrozenDict]`):
+                A `PyTree` of model parameters.
+            mask (`Union[Dict, FrozenDict]`):
+                A `PyTree` with same structure as the `params` tree. The leaves should be booleans. It should be `True`
+                for params you want to cast, and `False` for those you want to skip.
+
+        Examples:
+
+        ```python
+        >>> from diffusers import FlaxUNet2DConditionModel
+
+        >>> # Download model and configuration from huggingface.co
+        >>> model, params = FlaxUNet2DConditionModel.from_pretrained("runwayml/stable-diffusion-v1-5")
+        >>> # By default, the model params will be in fp32, to illustrate the use of this method,
+        >>> # we'll first cast to fp16 and back to fp32
+        >>> params = model.to_f16(params)
+        >>> # now cast back to fp32
+        >>> params = model.to_fp32(params)
+        ```"""
+        return self._cast_floating_to(params, jnp.float32, mask)
+
+    def to_fp16(self, params: Union[Dict, FrozenDict], mask: Any = None):
+        r"""
+        Cast the floating-point `params` to `jax.numpy.float16`. This returns a new `params` tree and does not cast the
+        `params` in place.
+
+        This method can be used on a GPU to explicitly convert the model parameters to float16 precision to do full
+        half-precision training or to save weights in float16 for inference in order to save memory and improve speed.
+
+        Arguments:
+            params (`Union[Dict, FrozenDict]`):
+                A `PyTree` of model parameters.
+            mask (`Union[Dict, FrozenDict]`):
+                A `PyTree` with same structure as the `params` tree. The leaves should be booleans. It should be `True`
+                for params you want to cast, and `False` for those you want to skip.
+
+        Examples:
+
+        ```python
+        >>> from diffusers import FlaxUNet2DConditionModel
+
+        >>> # load model
+        >>> model, params = FlaxUNet2DConditionModel.from_pretrained("runwayml/stable-diffusion-v1-5")
+        >>> # By default, the model params will be in fp32, to cast these to float16
+        >>> params = model.to_fp16(params)
+        >>> # If you want don't want to cast certain parameters (for example layer norm bias and scale)
+        >>> # then pass the mask as follows
+        >>> from flax import traverse_util
+
+        >>> model, params = FlaxUNet2DConditionModel.from_pretrained("runwayml/stable-diffusion-v1-5")
+        >>> flat_params = traverse_util.flatten_dict(params)
+        >>> mask = {
+        ...     path: (path[-2] != ("LayerNorm", "bias") and path[-2:] != ("LayerNorm", "scale"))
+        ...     for path in flat_params
+        ... }
+        >>> mask = traverse_util.unflatten_dict(mask)
+        >>> params = model.to_fp16(params, mask)
+        ```"""
+        return self._cast_floating_to(params, jnp.float16, mask)
+
+    def init_weights(self, rng: jax.Array) -> Dict:
+        raise NotImplementedError(f"init_weights method has to be implemented for {self}")
+
+    @classmethod
+    @validate_hf_hub_args
+    def from_pretrained(
+        cls,
+        pretrained_model_name_or_path: Union[str, os.PathLike],
+        dtype: jnp.dtype = jnp.float32,
+        *model_args,
+        **kwargs,
+    ):
+        r"""
+        Instantiate a pretrained Flax model from a pretrained model configuration.
+
+        Parameters:
+            pretrained_model_name_or_path (`str` or `os.PathLike`):
+                Can be either:
+
+                    - A string, the *model id* (for example `runwayml/stable-diffusion-v1-5`) of a pretrained model
+                      hosted on the Hub.
+                    - A path to a *directory* (for example `./my_model_directory`) containing the model weights saved
+                      using [`~FlaxModelMixin.save_pretrained`].
+            dtype (`jax.numpy.dtype`, *optional*, defaults to `jax.numpy.float32`):
+                The data type of the computation. Can be one of `jax.numpy.float32`, `jax.numpy.float16` (on GPUs) and
+                `jax.numpy.bfloat16` (on TPUs).
+
+                This can be used to enable mixed-precision training or half-precision inference on GPUs or TPUs. If
+                specified, all the computation will be performed with the given `dtype`.
+
+                <Tip>
+
+                This only specifies the dtype of the *computation* and does not influence the dtype of model
+                parameters.
+
+                If you wish to change the dtype of the model parameters, see [`~FlaxModelMixin.to_fp16`] and
+                [`~FlaxModelMixin.to_bf16`].
+
+                </Tip>
+
+            model_args (sequence of positional arguments, *optional*):
+                All remaining positional arguments are passed to the underlying model's `__init__` method.
+            cache_dir (`Union[str, os.PathLike]`, *optional*):
+                Path to a directory where a downloaded pretrained model configuration is cached if the standard cache
+                is not used.
+            force_download (`bool`, *optional*, defaults to `False`):
+                Whether or not to force the (re-)download of the model weights and configuration files, overriding the
+                cached versions if they exist.
+            resume_download (`bool`, *optional*, defaults to `False`):
+                Whether or not to resume downloading the model weights and configuration files. If set to `False`, any
+                incompletely downloaded files are deleted.
+            proxies (`Dict[str, str]`, *optional*):
+                A dictionary of proxy servers to use by protocol or endpoint, for example, `{'http': 'foo.bar:3128',
+                'http://hostname': 'foo.bar:4012'}`. The proxies are used on each request.
+            local_files_only(`bool`, *optional*, defaults to `False`):
+                Whether to only load local model weights and configuration files or not. If set to `True`, the model
+                won't be downloaded from the Hub.
+            revision (`str`, *optional*, defaults to `"main"`):
+                The specific model version to use. It can be a branch name, a tag name, a commit id, or any identifier
+                allowed by Git.
+            from_pt (`bool`, *optional*, defaults to `False`):
+                Load the model weights from a PyTorch checkpoint save file.
+            kwargs (remaining dictionary of keyword arguments, *optional*):
+                Can be used to update the configuration object (after it is loaded) and initiate the model (for
+                example, `output_attentions=True`). Behaves differently depending on whether a `config` is provided or
+                automatically loaded:
+
+                    - If a configuration is provided with `config`, `kwargs` are directly passed to the underlying
+                      model's `__init__` method (we assume all relevant updates to the configuration have already been
+                      done).
+                    - If a configuration is not provided, `kwargs` are first passed to the configuration class
+                      initialization function [`~ConfigMixin.from_config`]. Each key of the `kwargs` that corresponds
+                      to a configuration attribute is used to override said attribute with the supplied `kwargs` value.
+                      Remaining keys that do not correspond to any configuration attribute are passed to the underlying
+                      model's `__init__` function.
+
+        Examples:
+
+        ```python
+        >>> from diffusers import FlaxUNet2DConditionModel
+
+        >>> # Download model and configuration from huggingface.co and cache.
+        >>> model, params = FlaxUNet2DConditionModel.from_pretrained("runwayml/stable-diffusion-v1-5")
+        >>> # Model was saved using *save_pretrained('./test/saved_model/')* (for example purposes, not runnable).
+        >>> model, params = FlaxUNet2DConditionModel.from_pretrained("./test/saved_model/")
+        ```
+
+        If you get the error message below, you need to finetune the weights for your downstream task:
+
+        ```bash
+        Some weights of UNet2DConditionModel were not initialized from the model checkpoint at runwayml/stable-diffusion-v1-5 and are newly initialized because the shapes did not match:
+        - conv_in.weight: found shape torch.Size([320, 4, 3, 3]) in the checkpoint and torch.Size([320, 9, 3, 3]) in the model instantiated
+        You should probably TRAIN this model on a down-stream task to be able to use it for predictions and inference.
+        ```
+        """
+        config = kwargs.pop("config", None)
+        cache_dir = kwargs.pop("cache_dir", None)
+        force_download = kwargs.pop("force_download", False)
+        from_pt = kwargs.pop("from_pt", False)
+        resume_download = kwargs.pop("resume_download", False)
+        proxies = kwargs.pop("proxies", None)
+        local_files_only = kwargs.pop("local_files_only", False)
+        token = kwargs.pop("token", None)
+        revision = kwargs.pop("revision", None)
+        subfolder = kwargs.pop("subfolder", None)
+
+        user_agent = {
+            "diffusers": __version__,
+            "file_type": "model",
+            "framework": "flax",
+        }
+
+        # Load config if we don't provide one
+        if config is None:
+            config, unused_kwargs = cls.load_config(
+                pretrained_model_name_or_path,
+                cache_dir=cache_dir,
+                return_unused_kwargs=True,
+                force_download=force_download,
+                resume_download=resume_download,
+                proxies=proxies,
+                local_files_only=local_files_only,
+                token=token,
+                revision=revision,
+                subfolder=subfolder,
+                **kwargs,
+            )
+
+        model, model_kwargs = cls.from_config(config, dtype=dtype, return_unused_kwargs=True, **unused_kwargs)
+
+        # Load model
+        pretrained_path_with_subfolder = (
+            pretrained_model_name_or_path
+            if subfolder is None
+            else os.path.join(pretrained_model_name_or_path, subfolder)
+        )
+        if os.path.isdir(pretrained_path_with_subfolder):
+            if from_pt:
+                if not os.path.isfile(os.path.join(pretrained_path_with_subfolder, WEIGHTS_NAME)):
+                    raise EnvironmentError(
+                        f"Error no file named {WEIGHTS_NAME} found in directory {pretrained_path_with_subfolder} "
+                    )
+                model_file = os.path.join(pretrained_path_with_subfolder, WEIGHTS_NAME)
+            elif os.path.isfile(os.path.join(pretrained_path_with_subfolder, FLAX_WEIGHTS_NAME)):
+                # Load from a Flax checkpoint
+                model_file = os.path.join(pretrained_path_with_subfolder, FLAX_WEIGHTS_NAME)
+            # Check if pytorch weights exist instead
+            elif os.path.isfile(os.path.join(pretrained_path_with_subfolder, WEIGHTS_NAME)):
+                raise EnvironmentError(
+                    f"{WEIGHTS_NAME} file found in directory {pretrained_path_with_subfolder}. Please load the model"
+                    " using `from_pt=True`."
+                )
+            else:
+                raise EnvironmentError(
+                    f"Error no file named {FLAX_WEIGHTS_NAME} or {WEIGHTS_NAME} found in directory "
+                    f"{pretrained_path_with_subfolder}."
+                )
+        else:
+            try:
+                model_file = hf_hub_download(
+                    pretrained_model_name_or_path,
+                    filename=FLAX_WEIGHTS_NAME if not from_pt else WEIGHTS_NAME,
+                    cache_dir=cache_dir,
+                    force_download=force_download,
+                    proxies=proxies,
+                    resume_download=resume_download,
+                    local_files_only=local_files_only,
+                    token=token,
+                    user_agent=user_agent,
+                    subfolder=subfolder,
+                    revision=revision,
+                )
+
+            except RepositoryNotFoundError:
+                raise EnvironmentError(
+                    f"{pretrained_model_name_or_path} is not a local folder and is not a valid model identifier "
+                    "listed on 'https://huggingface.co/models'\nIf this is a private repository, make sure to pass a "
+                    "token having permission to this repo with `token` or log in with `huggingface-cli "
+                    "login`."
+                )
+            except RevisionNotFoundError:
+                raise EnvironmentError(
+                    f"{revision} is not a valid git identifier (branch name, tag name or commit id) that exists for "
+                    "this model name. Check the model page at "
+                    f"'https://huggingface.co/{pretrained_model_name_or_path}' for available revisions."
+                )
+            except EntryNotFoundError:
+                raise EnvironmentError(
+                    f"{pretrained_model_name_or_path} does not appear to have a file named {FLAX_WEIGHTS_NAME}."
+                )
+            except HTTPError as err:
+                raise EnvironmentError(
+                    f"There was a specific connection error when trying to load {pretrained_model_name_or_path}:\n"
+                    f"{err}"
+                )
+            except ValueError:
+                raise EnvironmentError(
+                    f"We couldn't connect to '{HUGGINGFACE_CO_RESOLVE_ENDPOINT}' to load this model, couldn't find it"
+                    f" in the cached files and it looks like {pretrained_model_name_or_path} is not the path to a"
+                    f" directory containing a file named {FLAX_WEIGHTS_NAME} or {WEIGHTS_NAME}.\nCheckout your"
+                    " internet connection or see how to run the library in offline mode at"
+                    " 'https://huggingface.co/docs/transformers/installation#offline-mode'."
+                )
+            except EnvironmentError:
+                raise EnvironmentError(
+                    f"Can't load the model for '{pretrained_model_name_or_path}'. If you were trying to load it from "
+                    "'https://huggingface.co/models', make sure you don't have a local directory with the same name. "
+                    f"Otherwise, make sure '{pretrained_model_name_or_path}' is the correct path to a directory "
+                    f"containing a file named {FLAX_WEIGHTS_NAME} or {WEIGHTS_NAME}."
+                )
+
+        if from_pt:
+            if is_torch_available():
+                from .modeling_utils import load_state_dict
+            else:
+                raise EnvironmentError(
+                    "Can't load the model in PyTorch format because PyTorch is not installed. "
+                    "Please, install PyTorch or use native Flax weights."
+                )
+
+            # Step 1: Get the pytorch file
+            pytorch_model_file = load_state_dict(model_file)
+
+            # Step 2: Convert the weights
+            state = convert_pytorch_state_dict_to_flax(pytorch_model_file, model)
+        else:
+            try:
+                with open(model_file, "rb") as state_f:
+                    state = from_bytes(cls, state_f.read())
+            except (UnpicklingError, msgpack.exceptions.ExtraData) as e:
+                try:
+                    with open(model_file) as f:
+                        if f.read().startswith("version"):
+                            raise OSError(
+                                "You seem to have cloned a repository without having git-lfs installed. Please"
+                                " install git-lfs and run `git lfs install` followed by `git lfs pull` in the"
+                                " folder you cloned."
+                            )
+                        else:
+                            raise ValueError from e
+                except (UnicodeDecodeError, ValueError):
+                    raise EnvironmentError(f"Unable to convert {model_file} to Flax deserializable object. ")
+            # make sure all arrays are stored as jnp.ndarray
+            # NOTE: This is to prevent a bug this will be fixed in Flax >= v0.3.4:
+            # https://github.com/google/flax/issues/1261
+        state = jax.tree_util.tree_map(lambda x: jax.device_put(x, jax.local_devices(backend="cpu")[0]), state)
+
+        # flatten dicts
+        state = flatten_dict(state)
+
+        params_shape_tree = jax.eval_shape(model.init_weights, rng=jax.random.PRNGKey(0))
+        required_params = set(flatten_dict(unfreeze(params_shape_tree)).keys())
+
+        shape_state = flatten_dict(unfreeze(params_shape_tree))
+
+        missing_keys = required_params - set(state.keys())
+        unexpected_keys = set(state.keys()) - required_params
+
+        if missing_keys:
+            logger.warning(
+                f"The checkpoint {pretrained_model_name_or_path} is missing required keys: {missing_keys}. "
+                "Make sure to call model.init_weights to initialize the missing weights."
+            )
+            cls._missing_keys = missing_keys
+
+        for key in state.keys():
+            if key in shape_state and state[key].shape != shape_state[key].shape:
+                raise ValueError(
+                    f"Trying to load the pretrained weight for {key} failed: checkpoint has shape "
+                    f"{state[key].shape} which is incompatible with the model shape {shape_state[key].shape}. "
+                )
+
+        # remove unexpected keys to not be saved again
+        for unexpected_key in unexpected_keys:
+            del state[unexpected_key]
+
+        if len(unexpected_keys) > 0:
+            logger.warning(
+                f"Some weights of the model checkpoint at {pretrained_model_name_or_path} were not used when"
+                f" initializing {model.__class__.__name__}: {unexpected_keys}\n- This IS expected if you are"
+                f" initializing {model.__class__.__name__} from the checkpoint of a model trained on another task or"
+                " with another architecture."
+            )
+        else:
+            logger.info(f"All model checkpoint weights were used when initializing {model.__class__.__name__}.\n")
+
+        if len(missing_keys) > 0:
+            logger.warning(
+                f"Some weights of {model.__class__.__name__} were not initialized from the model checkpoint at"
+                f" {pretrained_model_name_or_path} and are newly initialized: {missing_keys}\nYou should probably"
+                " TRAIN this model on a down-stream task to be able to use it for predictions and inference."
+            )
+        else:
+            logger.info(
+                f"All the weights of {model.__class__.__name__} were initialized from the model checkpoint at"
+                f" {pretrained_model_name_or_path}.\nIf your task is similar to the task the model of the checkpoint"
+                f" was trained on, you can already use {model.__class__.__name__} for predictions without further"
+                " training."
+            )
+
+        return model, unflatten_dict(state)
+
+    def save_pretrained(
+        self,
+        save_directory: Union[str, os.PathLike],
+        params: Union[Dict, FrozenDict],
+        is_main_process: bool = True,
+        push_to_hub: bool = False,
+        **kwargs,
+    ):
+        """
+        Save a model and its configuration file to a directory so that it can be reloaded using the
+        [`~FlaxModelMixin.from_pretrained`] class method.
+
+        Arguments:
+            save_directory (`str` or `os.PathLike`):
+                Directory to save a model and its configuration file to. Will be created if it doesn't exist.
+            params (`Union[Dict, FrozenDict]`):
+                A `PyTree` of model parameters.
+            is_main_process (`bool`, *optional*, defaults to `True`):
+                Whether the process calling this is the main process or not. Useful during distributed training and you
+                need to call this function on all processes. In this case, set `is_main_process=True` only on the main
+                process to avoid race conditions.
+            push_to_hub (`bool`, *optional*, defaults to `False`):
+                Whether or not to push your model to the Hugging Face model hub after saving it. You can specify the
+                repository you want to push to with `repo_id` (will default to the name of `save_directory` in your
+                namespace).
+            kwargs (`Dict[str, Any]`, *optional*):
+                Additional key word arguments passed along to the [`~utils.PushToHubMixin.push_to_hub`] method.
+        """
+        if os.path.isfile(save_directory):
+            logger.error(f"Provided path ({save_directory}) should be a directory, not a file")
+            return
+
+        os.makedirs(save_directory, exist_ok=True)
+
+        if push_to_hub:
+            commit_message = kwargs.pop("commit_message", None)
+            private = kwargs.pop("private", False)
+            create_pr = kwargs.pop("create_pr", False)
+            token = kwargs.pop("token", None)
+            repo_id = kwargs.pop("repo_id", save_directory.split(os.path.sep)[-1])
+            repo_id = create_repo(repo_id, exist_ok=True, private=private, token=token).repo_id
+
+        model_to_save = self
+
+        # Attach architecture to the config
+        # Save the config
+        if is_main_process:
+            model_to_save.save_config(save_directory)
+
+        # save model
+        output_model_file = os.path.join(save_directory, FLAX_WEIGHTS_NAME)
+        with open(output_model_file, "wb") as f:
+            model_bytes = to_bytes(params)
+            f.write(model_bytes)
+
+        logger.info(f"Model weights saved in {output_model_file}")
+
+        if push_to_hub:
+            self._upload_folder(
+                save_directory,
+                repo_id,
+                token=token,
+                commit_message=commit_message,
+                create_pr=create_pr,
+            )

diffusers-0.27.0/src/diffusers/models/modeling_outputs.py

+from dataclasses import dataclass
+
+from ..utils import BaseOutput
+
+
+@dataclass
+class AutoencoderKLOutput(BaseOutput):
+    """
+    Output of AutoencoderKL encoding method.
+
+    Args:
+        latent_dist (`DiagonalGaussianDistribution`):
+            Encoded outputs of `Encoder` represented as the mean and logvar of `DiagonalGaussianDistribution`.
+            `DiagonalGaussianDistribution` allows for sampling latents from the distribution.
+    """
+
+    latent_dist: "DiagonalGaussianDistribution"  # noqa: F821

diffusers-0.27.0/src/diffusers/models/modeling_pytorch_flax_utils.py

+# coding=utf-8
+# Copyright 2024 The HuggingFace Inc. team.
+#
+# 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.
+""" PyTorch - Flax general utilities."""
+
+from pickle import UnpicklingError
+
+import jax
+import jax.numpy as jnp
+import numpy as np
+from flax.serialization import from_bytes
+from flax.traverse_util import flatten_dict
+
+from ..utils import logging
+
+
+logger = logging.get_logger(__name__)
+
+
+#####################
+# Flax => PyTorch #
+#####################
+
+
+# from https://github.com/huggingface/transformers/blob/main/src/transformers/modeling_flax_pytorch_utils.py#L224-L352
+def load_flax_checkpoint_in_pytorch_model(pt_model, model_file):
+    try:
+        with open(model_file, "rb") as flax_state_f:
+            flax_state = from_bytes(None, flax_state_f.read())
+    except UnpicklingError as e:
+        try:
+            with open(model_file) as f:
+                if f.read().startswith("version"):
+                    raise OSError(
+                        "You seem to have cloned a repository without having git-lfs installed. Please"
+                        " install git-lfs and run `git lfs install` followed by `git lfs pull` in the"
+                        " folder you cloned."
+                    )
+                else:
+                    raise ValueError from e
+        except (UnicodeDecodeError, ValueError):
+            raise EnvironmentError(f"Unable to convert {model_file} to Flax deserializable object. ")
+
+    return load_flax_weights_in_pytorch_model(pt_model, flax_state)
+
+
+def load_flax_weights_in_pytorch_model(pt_model, flax_state):
+    """Load flax checkpoints in a PyTorch model"""
+
+    try:
+        import torch  # noqa: F401
+    except ImportError:
+        logger.error(
+            "Loading Flax weights in PyTorch requires both PyTorch and Flax to be installed. Please see"
+            " https://pytorch.org/ and https://flax.readthedocs.io/en/latest/installation.html for installation"
+            " instructions."
+        )
+        raise
+
+    # check if we have bf16 weights
+    is_type_bf16 = flatten_dict(jax.tree_util.tree_map(lambda x: x.dtype == jnp.bfloat16, flax_state)).values()
+    if any(is_type_bf16):
+        # convert all weights to fp32 if they are bf16 since torch.from_numpy can-not handle bf16
+
+        # and bf16 is not fully supported in PT yet.
+        logger.warning(
+            "Found ``bfloat16`` weights in Flax model. Casting all ``bfloat16`` weights to ``float32`` "
+            "before loading those in PyTorch model."
+        )
+        flax_state = jax.tree_util.tree_map(
+            lambda params: params.astype(np.float32) if params.dtype == jnp.bfloat16 else params, flax_state
+        )
+
+    pt_model.base_model_prefix = ""
+
+    flax_state_dict = flatten_dict(flax_state, sep=".")
+    pt_model_dict = pt_model.state_dict()
+
+    # keep track of unexpected & missing keys
+    unexpected_keys = []
+    missing_keys = set(pt_model_dict.keys())
+
+    for flax_key_tuple, flax_tensor in flax_state_dict.items():
+        flax_key_tuple_array = flax_key_tuple.split(".")
+
+        if flax_key_tuple_array[-1] == "kernel" and flax_tensor.ndim == 4:
+            flax_key_tuple_array = flax_key_tuple_array[:-1] + ["weight"]
+            flax_tensor = jnp.transpose(flax_tensor, (3, 2, 0, 1))
+        elif flax_key_tuple_array[-1] == "kernel":
+            flax_key_tuple_array = flax_key_tuple_array[:-1] + ["weight"]
+            flax_tensor = flax_tensor.T
+        elif flax_key_tuple_array[-1] == "scale":
+            flax_key_tuple_array = flax_key_tuple_array[:-1] + ["weight"]
+
+        if "time_embedding" not in flax_key_tuple_array:
+            for i, flax_key_tuple_string in enumerate(flax_key_tuple_array):
+                flax_key_tuple_array[i] = (
+                    flax_key_tuple_string.replace("_0", ".0")
+                    .replace("_1", ".1")
+                    .replace("_2", ".2")
+                    .replace("_3", ".3")
+                    .replace("_4", ".4")
+                    .replace("_5", ".5")
+                    .replace("_6", ".6")
+                    .replace("_7", ".7")
+                    .replace("_8", ".8")
+                    .replace("_9", ".9")
+                )
+
+        flax_key = ".".join(flax_key_tuple_array)
+
+        if flax_key in pt_model_dict:
+            if flax_tensor.shape != pt_model_dict[flax_key].shape:
+                raise ValueError(
+                    f"Flax checkpoint seems to be incorrect. Weight {flax_key_tuple} was expected "
+                    f"to be of shape {pt_model_dict[flax_key].shape}, but is {flax_tensor.shape}."
+                )
+            else:
+                # add weight to pytorch dict
+                flax_tensor = np.asarray(flax_tensor) if not isinstance(flax_tensor, np.ndarray) else flax_tensor
+                pt_model_dict[flax_key] = torch.from_numpy(flax_tensor)
+                # remove from missing keys
+                missing_keys.remove(flax_key)
+        else:
+            # weight is not expected by PyTorch model
+            unexpected_keys.append(flax_key)
+
+    pt_model.load_state_dict(pt_model_dict)
+
+    # re-transform missing_keys to list
+    missing_keys = list(missing_keys)
+
+    if len(unexpected_keys) > 0:
+        logger.warning(
+            "Some weights of the Flax model were not used when initializing the PyTorch model"
+            f" {pt_model.__class__.__name__}: {unexpected_keys}\n- This IS expected if you are initializing"
+            f" {pt_model.__class__.__name__} from a Flax model trained on another task or with another architecture"
+            " (e.g. initializing a BertForSequenceClassification model from a FlaxBertForPreTraining model).\n- This"
+            f" IS NOT expected if you are initializing {pt_model.__class__.__name__} from a Flax model that you expect"
+            " to be exactly identical (e.g. initializing a BertForSequenceClassification model from a"
+            " FlaxBertForSequenceClassification model)."
+        )
+    if len(missing_keys) > 0:
+        logger.warning(
+            f"Some weights of {pt_model.__class__.__name__} were not initialized from the Flax model and are newly"
+            f" initialized: {missing_keys}\nYou should probably TRAIN this model on a down-stream task to be able to"
+            " use it for predictions and inference."
+        )
+
+    return pt_model