flux/controlnet_flux.py

# Copyright 2024 Black Forest Labs, The HuggingFace Team and The InstantX Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

from dataclasses import dataclass
from typing import Any, Dict, List, Optional, Tuple, Union

import torch
import torch.nn as nn

from diffusers.configuration_utils import ConfigMixin, register_to_config
from .lora.peft import PeftAdapterMixin
from diffusers.models.attention_processor import AttentionProcessor
from diffusers.models.modeling_utils import ModelMixin
from diffusers.utils import USE_PEFT_BACKEND, is_torch_version, logging, scale_lora_layers, unscale_lora_layers
#from .controlnet import BaseOutput, zero_module
from diffusers.utils import BaseOutput
from .embeddings import CombinedTimestepGuidanceTextProjEmbeddings, CombinedTimestepTextProjEmbeddings
from diffusers.models.modeling_outputs import Transformer2DModelOutput
from .transformer_flux import FluxSingleTransformerBlock, FluxTransformerBlock
import numpy as np


logger = logging.get_logger(__name__)  # pylint: disable=invalid-name

def zero_module(module):
    for p in module.parameters():
        nn.init.zeros_(p)
    return module

def get_1d_rotary_pos_embed(
    dim: int,
    pos: Union[np.ndarray, int],
    theta: float = 10000.0,
    use_real=False,
    linear_factor=1.0,
    ntk_factor=1.0,
    repeat_interleave_real=True,
    freqs_dtype=torch.float32,  #  torch.float32, torch.float64 (flux)
):
    """
    Precompute the frequency tensor for complex exponentials (cis) with given dimensions.

    This function calculates a frequency tensor with complex exponentials using the given dimension 'dim' and the end
    index 'end'. The 'theta' parameter scales the frequencies. The returned tensor contains complex values in complex64
    data type.

    Args:
        dim (`int`): Dimension of the frequency tensor.
        pos (`np.ndarray` or `int`): Position indices for the frequency tensor. [S] or scalar
        theta (`float`, *optional*, defaults to 10000.0):
            Scaling factor for frequency computation. Defaults to 10000.0.
        use_real (`bool`, *optional*):
            If True, return real part and imaginary part separately. Otherwise, return complex numbers.
        linear_factor (`float`, *optional*, defaults to 1.0):
            Scaling factor for the context extrapolation. Defaults to 1.0.
        ntk_factor (`float`, *optional*, defaults to 1.0):
            Scaling factor for the NTK-Aware RoPE. Defaults to 1.0.
        repeat_interleave_real (`bool`, *optional*, defaults to `True`):
            If `True` and `use_real`, real part and imaginary part are each interleaved with themselves to reach `dim`.
            Otherwise, they are concateanted with themselves.
        freqs_dtype (`torch.float32` or `torch.float64`, *optional*, defaults to `torch.float32`):
            the dtype of the frequency tensor.
    Returns:
        `torch.Tensor`: Precomputed frequency tensor with complex exponentials. [S, D/2]
    """
    assert dim % 2 == 0

    if isinstance(pos, int):
        pos = torch.arange(pos)
    if isinstance(pos, np.ndarray):
        pos = torch.from_numpy(pos)  # type: ignore  # [S]

    theta = theta * ntk_factor
    freqs = 1.0 / (theta ** (torch.arange(0, dim, 2, dtype=freqs_dtype)[: (dim // 2)] / dim)) / linear_factor  # [D/2]
    freqs = freqs.to(pos.device)
    freqs = torch.outer(pos, freqs)  # type: ignore   # [S, D/2]
    if use_real and repeat_interleave_real:
        # flux, hunyuan-dit, cogvideox
        freqs_cos = freqs.cos().repeat_interleave(2, dim=1).float()  # [S, D]
        freqs_sin = freqs.sin().repeat_interleave(2, dim=1).float()  # [S, D]
        return freqs_cos, freqs_sin
    elif use_real:
        # stable audio
        freqs_cos = torch.cat([freqs.cos(), freqs.cos()], dim=-1).float()  # [S, D]
        freqs_sin = torch.cat([freqs.sin(), freqs.sin()], dim=-1).float()  # [S, D]
        return freqs_cos, freqs_sin
    else:
        # lumina
        freqs_cis = torch.polar(torch.ones_like(freqs), freqs)  # complex64     # [S, D/2]
        return freqs_cis

class FluxPosEmbed(nn.Module):
    # modified from https://github.com/black-forest-labs/flux/blob/c00d7c60b085fce8058b9df845e036090873f2ce/src/flux/modules/layers.py#L11
    def __init__(self, theta: int, axes_dim: List[int]):
        super().__init__()
        self.theta = theta
        self.axes_dim = axes_dim

    def forward(self, ids: torch.Tensor) -> torch.Tensor:
        n_axes = ids.shape[-1]
        cos_out = []
        sin_out = []
        pos = ids.squeeze().float()
        is_mps = ids.device.type == "mps"
        freqs_dtype = torch.float32 if is_mps else torch.float64
        for i in range(n_axes):
            cos, sin = get_1d_rotary_pos_embed(
                self.axes_dim[i], pos[:, i], repeat_interleave_real=True, use_real=True, freqs_dtype=freqs_dtype
            )
            cos_out.append(cos)
            sin_out.append(sin)
        freqs_cos = torch.cat(cos_out, dim=-1).to(ids.device)
        freqs_sin = torch.cat(sin_out, dim=-1).to(ids.device)
        return freqs_cos, freqs_sin


@dataclass
class FluxControlNetOutput(BaseOutput):
    controlnet_block_samples: Tuple[torch.Tensor]
    controlnet_single_block_samples: Tuple[torch.Tensor]


class FluxControlNetModel(ModelMixin, ConfigMixin, PeftAdapterMixin):
    _supports_gradient_checkpointing = True

    @register_to_config
    def __init__(
        self,
        patch_size: int = 1,
        in_channels: int = 64,
        num_layers: int = 19,
        num_single_layers: int = 38,
        attention_head_dim: int = 128,
        num_attention_heads: int = 24,
        joint_attention_dim: int = 4096,
        pooled_projection_dim: int = 768,
        guidance_embeds: bool = False,
        axes_dims_rope: List[int] = [16, 56, 56],
        num_mode: int = None,
    ):
        super().__init__()
        self.out_channels = in_channels
        self.inner_dim = num_attention_heads * attention_head_dim

        self.pos_embed = FluxPosEmbed(theta=10000, axes_dim=axes_dims_rope)
        text_time_guidance_cls = (
            CombinedTimestepGuidanceTextProjEmbeddings if guidance_embeds else CombinedTimestepTextProjEmbeddings
        )
        self.time_text_embed = text_time_guidance_cls(
            embedding_dim=self.inner_dim, pooled_projection_dim=pooled_projection_dim
        )

        self.context_embedder = nn.Linear(joint_attention_dim, self.inner_dim)
        self.x_embedder = torch.nn.Linear(in_channels, self.inner_dim)

        self.transformer_blocks = nn.ModuleList(
            [
                FluxTransformerBlock(
                    dim=self.inner_dim,
                    num_attention_heads=num_attention_heads,
                    attention_head_dim=attention_head_dim,
                )
                for i in range(num_layers)
            ]
        )

        self.single_transformer_blocks = nn.ModuleList(
            [
                FluxSingleTransformerBlock(
                    dim=self.inner_dim,
                    num_attention_heads=num_attention_heads,
                    attention_head_dim=attention_head_dim,
                )
                for i in range(num_single_layers)
            ]
        )

        # controlnet_blocks
        self.controlnet_blocks = nn.ModuleList([])
        for _ in range(len(self.transformer_blocks)):
            self.controlnet_blocks.append(zero_module(nn.Linear(self.inner_dim, self.inner_dim)))

        self.controlnet_single_blocks = nn.ModuleList([])
        for _ in range(len(self.single_transformer_blocks)):
            self.controlnet_single_blocks.append(zero_module(nn.Linear(self.inner_dim, self.inner_dim)))

        self.union = num_mode is not None
        if self.union:
            self.controlnet_mode_embedder = nn.Embedding(num_mode, self.inner_dim)

        self.controlnet_x_embedder = zero_module(torch.nn.Linear(in_channels, self.inner_dim))

        self.gradient_checkpointing = False

    @property
    # Copied from diffusers.models.unets.unet_2d_condition.UNet2DConditionModel.attn_processors
    def attn_processors(self):
        r"""
        Returns:
            `dict` of attention processors: A dictionary containing all attention processors used in the model with
            indexed by its weight name.
        """
        # set recursively
        processors = {}

        def fn_recursive_add_processors(name: str, module: torch.nn.Module, processors: Dict[str, AttentionProcessor]):
            if hasattr(module, "get_processor"):
                processors[f"{name}.processor"] = module.get_processor()

            for sub_name, child in module.named_children():
                fn_recursive_add_processors(f"{name}.{sub_name}", child, processors)

            return processors

        for name, module in self.named_children():
            fn_recursive_add_processors(name, module, processors)

        return processors

    # Copied from diffusers.models.unets.unet_2d_condition.UNet2DConditionModel.set_attn_processor
    def set_attn_processor(self, processor):
        r"""
        Sets the attention processor to use to compute attention.

        Parameters:
            processor (`dict` of `AttentionProcessor` or only `AttentionProcessor`):
                The instantiated processor class or a dictionary of processor classes that will be set as the processor
                for **all** `Attention` layers.

                If `processor` is a dict, the key needs to define the path to the corresponding cross attention
                processor. This is strongly recommended when setting trainable attention processors.

        """
        count = len(self.attn_processors.keys())

        if isinstance(processor, dict) and len(processor) != count:
            raise ValueError(
                f"A dict of processors was passed, but the number of processors {len(processor)} does not match the"
                f" number of attention layers: {count}. Please make sure to pass {count} processor classes."
            )

        def fn_recursive_attn_processor(name: str, module: torch.nn.Module, processor):
            if hasattr(module, "set_processor"):
                if not isinstance(processor, dict):
                    module.set_processor(processor)
                else:
                    module.set_processor(processor.pop(f"{name}.processor"))

            for sub_name, child in module.named_children():
                fn_recursive_attn_processor(f"{name}.{sub_name}", child, processor)

        for name, module in self.named_children():
            fn_recursive_attn_processor(name, module, processor)

    def _set_gradient_checkpointing(self, module, value=False):
        if hasattr(module, "gradient_checkpointing"):
            module.gradient_checkpointing = value

    @classmethod
    def from_transformer(
        cls,
        transformer,
        num_layers: int = 4,
        num_single_layers: int = 10,
        attention_head_dim: int = 128,
        num_attention_heads: int = 24,
        load_weights_from_transformer=True,
    ):
        config = transformer.config
        config["num_layers"] = num_layers
        config["num_single_layers"] = num_single_layers
        config["attention_head_dim"] = attention_head_dim
        config["num_attention_heads"] = num_attention_heads

        controlnet = cls(**config)

        if load_weights_from_transformer:
            controlnet.pos_embed.load_state_dict(transformer.pos_embed.state_dict())
            controlnet.time_text_embed.load_state_dict(transformer.time_text_embed.state_dict())
            controlnet.context_embedder.load_state_dict(transformer.context_embedder.state_dict())
            controlnet.x_embedder.load_state_dict(transformer.x_embedder.state_dict())
            controlnet.transformer_blocks.load_state_dict(transformer.transformer_blocks.state_dict(), strict=False)
            controlnet.single_transformer_blocks.load_state_dict(
                transformer.single_transformer_blocks.state_dict(), strict=False
            )

            controlnet.controlnet_x_embedder = zero_module(controlnet.controlnet_x_embedder)

        return controlnet

    def forward(
        self,
        hidden_states: torch.Tensor,
        controlnet_cond: torch.Tensor,
        controlnet_mode: torch.Tensor = None,
        conditioning_scale: float = 1.0,
        encoder_hidden_states: torch.Tensor = None,
        t5_encoder_hidden_states: torch.Tensor = None,
        pooled_projections: torch.Tensor = None,
        timestep: torch.LongTensor = None,
        img_ids: torch.Tensor = None,
        txt_ids: torch.Tensor = None,
        guidance: torch.Tensor = None,
        joint_attention_kwargs: Optional[Dict[str, Any]] = None,
        return_dict: bool = True,
    ) -> Union[torch.FloatTensor, Transformer2DModelOutput]:
        """
        The [`FluxTransformer2DModel`] forward method.

        Args:
            hidden_states (`torch.FloatTensor` of shape `(batch size, channel, height, width)`):
                Input `hidden_states`.
            controlnet_cond (`torch.Tensor`):
                The conditional input tensor of shape `(batch_size, sequence_length, hidden_size)`.
            controlnet_mode (`torch.Tensor`):
                The mode tensor of shape `(batch_size, 1)`.
            conditioning_scale (`float`, defaults to `1.0`):
                The scale factor for ControlNet outputs.
            encoder_hidden_states (`torch.FloatTensor` of shape `(batch size, sequence_len, embed_dims)`):
                Conditional embeddings (embeddings computed from the input conditions such as prompts) to use.
            pooled_projections (`torch.FloatTensor` of shape `(batch_size, projection_dim)`): Embeddings projected
                from the embeddings of input conditions.
            timestep ( `torch.LongTensor`):
                Used to indicate denoising step.
            block_controlnet_hidden_states: (`list` of `torch.Tensor`):
                A list of tensors that if specified are added to the residuals of transformer blocks.
            joint_attention_kwargs (`dict`, *optional*):
                A kwargs dictionary that if specified is passed along to the `AttentionProcessor` as defined under
                `self.processor` in
                [diffusers.models.attention_processor](https://github.com/huggingface/diffusers/blob/main/src/diffusers/models/attention_processor.py).
            return_dict (`bool`, *optional*, defaults to `True`):
                Whether or not to return a [`~models.transformer_2d.Transformer2DModelOutput`] instead of a plain
                tuple.

        Returns:
            If `return_dict` is True, an [`~models.transformer_2d.Transformer2DModelOutput`] is returned, otherwise a
            `tuple` where the first element is the sample tensor.
        """
        if joint_attention_kwargs is not None:
            joint_attention_kwargs = joint_attention_kwargs.copy()
            lora_scale = joint_attention_kwargs.pop("scale", 1.0)
        else:
            lora_scale = 1.0

        if USE_PEFT_BACKEND:
            # weight the lora layers by setting `lora_scale` for each PEFT layer
            scale_lora_layers(self, lora_scale)
        else:
            if joint_attention_kwargs is not None and joint_attention_kwargs.get("scale", None) is not None:
                logger.warning(
                    "Passing `scale` via `joint_attention_kwargs` when not using the PEFT backend is ineffective."
                )
        hidden_states = self.x_embedder(hidden_states)

        # add
        hidden_states = hidden_states + self.controlnet_x_embedder(controlnet_cond)

        timestep = timestep.to(hidden_states.dtype) * 1000
        if guidance is not None:
            guidance = guidance.to(hidden_states.dtype) * 1000
        else:
            guidance = None
        temb = (
            self.time_text_embed(timestep, pooled_projections)
            if guidance is None
            else self.time_text_embed(timestep, guidance, pooled_projections)
        )
        encoder_hidden_states = self.context_embedder(encoder_hidden_states)
        if t5_encoder_hidden_states is not None:
            encoder_hidden_states = torch.cat([encoder_hidden_states, t5_encoder_hidden_states], dim=1)

        if txt_ids.ndim == 3:
            logger.warning(
                "Passing `txt_ids` 3d torch.Tensor is deprecated."
                "Please remove the batch dimension and pass it as a 2d torch Tensor"
            )
            txt_ids = txt_ids[0]

        if self.union:
            # union mode
            if controlnet_mode is None:
                raise ValueError("`controlnet_mode` cannot be `None` when applying ControlNet-Union")
            # union mode emb
            controlnet_mode_emb = self.controlnet_mode_embedder(controlnet_mode)
            encoder_hidden_states = torch.cat([controlnet_mode_emb, encoder_hidden_states], dim=1)
            txt_ids = torch.cat([txt_ids[:1], txt_ids], dim=0)

        if img_ids.ndim == 3:
            logger.warning(
                "Passing `img_ids` 3d torch.Tensor is deprecated."
                "Please remove the batch dimension and pass it as a 2d torch Tensor"
            )
            img_ids = img_ids[0]

        ids = torch.cat((txt_ids, img_ids), dim=0)
        image_rotary_emb = self.pos_embed(ids)

        block_samples = ()
        for index_block, block in enumerate(self.transformer_blocks):
            if self.training and self.gradient_checkpointing:

                def create_custom_forward(module, return_dict=None):
                    def custom_forward(*inputs):
                        if return_dict is not None:
                            return module(*inputs, return_dict=return_dict)
                        else:
                            return module(*inputs)

                    return custom_forward

                ckpt_kwargs: Dict[str, Any] = {"use_reentrant": False} if is_torch_version(">=", "1.11.0") else {}
                encoder_hidden_states, hidden_states = torch.utils.checkpoint.checkpoint(
                    create_custom_forward(block),
                    hidden_states,
                    encoder_hidden_states,
                    temb,
                    image_rotary_emb,
                    **ckpt_kwargs,
                )

            else:
                encoder_hidden_states, hidden_states = block(
                    hidden_states=hidden_states,
                    encoder_hidden_states=encoder_hidden_states,
                    temb=temb,
                    image_rotary_emb=image_rotary_emb,
                )
            block_samples = block_samples + (hidden_states,)

        hidden_states = torch.cat([encoder_hidden_states, hidden_states], dim=1)

        single_block_samples = ()
        for index_block, block in enumerate(self.single_transformer_blocks):
            if self.training and self.gradient_checkpointing:

                def create_custom_forward(module, return_dict=None):
                    def custom_forward(*inputs):
                        if return_dict is not None:
                            return module(*inputs, return_dict=return_dict)
                        else:
                            return module(*inputs)

                    return custom_forward

                ckpt_kwargs: Dict[str, Any] = {"use_reentrant": False} if is_torch_version(">=", "1.11.0") else {}
                hidden_states = torch.utils.checkpoint.checkpoint(
                    create_custom_forward(block),
                    hidden_states,
                    temb,
                    image_rotary_emb,
                    **ckpt_kwargs,
                )

            else:
                hidden_states = block(
                    hidden_states=hidden_states,
                    temb=temb,
                    image_rotary_emb=image_rotary_emb,
                )
            single_block_samples = single_block_samples + (hidden_states[:, encoder_hidden_states.shape[1] :],)

        # controlnet block
        controlnet_block_samples = ()
        for block_sample, controlnet_block in zip(block_samples, self.controlnet_blocks):
            block_sample = controlnet_block(block_sample)
            controlnet_block_samples = controlnet_block_samples + (block_sample,)

        controlnet_single_block_samples = ()
        for single_block_sample, controlnet_block in zip(single_block_samples, self.controlnet_single_blocks):
            single_block_sample = controlnet_block(single_block_sample)
            controlnet_single_block_samples = controlnet_single_block_samples + (single_block_sample,)

        # scaling
        controlnet_block_samples = [sample * conditioning_scale for sample in controlnet_block_samples]
        controlnet_single_block_samples = [sample * conditioning_scale for sample in controlnet_single_block_samples]

        controlnet_block_samples = None if len(controlnet_block_samples) == 0 else controlnet_block_samples
        controlnet_single_block_samples = (
            None if len(controlnet_single_block_samples) == 0 else controlnet_single_block_samples
        )

        if USE_PEFT_BACKEND:
            # remove `lora_scale` from each PEFT layer
            unscale_lora_layers(self, lora_scale)

        if not return_dict:
            return (controlnet_block_samples, controlnet_single_block_samples)

        return FluxControlNetOutput(
            controlnet_block_samples=controlnet_block_samples,
            controlnet_single_block_samples=controlnet_single_block_samples,
        )


class FluxMultiControlNetModel(ModelMixin):
    r"""
    `FluxMultiControlNetModel` wrapper class for Multi-FluxControlNetModel

    This module is a wrapper for multiple instances of the `FluxControlNetModel`. The `forward()` API is designed to be
    compatible with `FluxControlNetModel`.

    Args:
        controlnets (`List[FluxControlNetModel]`):
            Provides additional conditioning to the unet during the denoising process. You must set multiple
            `FluxControlNetModel` as a list.
    """

    def __init__(self, controlnets):
        super().__init__()
        self.nets = nn.ModuleList(controlnets)

    def forward(
        self,
        hidden_states: torch.FloatTensor,
        controlnet_cond: List[torch.tensor],
        controlnet_mode: List[torch.tensor],
        conditioning_scale: List[float],
        encoder_hidden_states: torch.Tensor = None,
        t5_encoder_hidden_states: torch.Tensor = None,
        pooled_projections: torch.Tensor = None,
        timestep: torch.LongTensor = None,
        img_ids: torch.Tensor = None,
        txt_ids: torch.Tensor = None,
        guidance: torch.Tensor = None,
        joint_attention_kwargs: Optional[Dict[str, Any]] = None,
        return_dict: bool = True,
    ) -> Union[FluxControlNetOutput, Tuple]:
        # ControlNet-Union with multiple conditions
        # only load one ControlNet for saving memories
        if len(self.nets) == 1 and self.nets[0].union:
            controlnet = self.nets[0]

            for i, (image, mode, scale) in enumerate(zip(controlnet_cond, controlnet_mode, conditioning_scale)):
                block_samples, single_block_samples = controlnet(
                    hidden_states=hidden_states,
                    controlnet_cond=image,
                    controlnet_mode=mode[:, None],
                    conditioning_scale=scale,
                    timestep=timestep,
                    guidance=guidance,
                    pooled_projections=pooled_projections,
                    encoder_hidden_states=encoder_hidden_states,
                    t5_encoder_hidden_states=t5_encoder_hidden_states,
                    txt_ids=txt_ids,
                    img_ids=img_ids,
                    joint_attention_kwargs=joint_attention_kwargs,
                    return_dict=return_dict,
                )

                # merge samples
                if i == 0:
                    control_block_samples = block_samples
                    control_single_block_samples = single_block_samples
                else:
                    control_block_samples = [
                        control_block_sample + block_sample
                        for control_block_sample, block_sample in zip(control_block_samples, block_samples)
                    ]

                    control_single_block_samples = [
                        control_single_block_sample + block_sample
                        for control_single_block_sample, block_sample in zip(
                            control_single_block_samples, single_block_samples
                        )
                    ]

        # Regular Multi-ControlNets
        # load all ControlNets into memories
        else:
            for i, (image, mode, scale, controlnet) in enumerate(
                zip(controlnet_cond, controlnet_mode, conditioning_scale, self.nets)
            ):
                block_samples, single_block_samples = controlnet(
                    hidden_states=hidden_states,
                    controlnet_cond=image,
                    controlnet_mode=mode[:, None],
                    conditioning_scale=scale,
                    timestep=timestep,
                    guidance=guidance,
                    pooled_projections=pooled_projections,
                    encoder_hidden_states=encoder_hidden_states,
                    txt_ids=txt_ids,
                    img_ids=img_ids,
                    joint_attention_kwargs=joint_attention_kwargs,
                    return_dict=return_dict,
                )

                # merge samples
                if i == 0:
                    control_block_samples = block_samples
                    control_single_block_samples = single_block_samples
                else:
                    if block_samples is not None and control_block_samples is not None:
                        control_block_samples = [
                            control_block_sample + block_sample
                            for control_block_sample, block_sample in zip(control_block_samples, block_samples)
                        ]
                    if single_block_samples is not None and control_single_block_samples is not None:
                        control_single_block_samples = [
                            control_single_block_sample + block_sample
                            for control_single_block_sample, block_sample in zip(
                                control_single_block_samples, single_block_samples
                            )
                        ]

        return control_block_samples, control_single_block_samples