Create custom_pipeline.py

custom_pipeline.py

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+# Copyright 2024 Black Forest Labs and 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 inspect
+from typing import Any, Callable, Dict, List, Optional, Union
+
+import numpy as np
+import torch
+from transformers import (
+ CLIPTextModel,
+ CLIPTokenizer,
+ T5EncoderModel,
+ T5TokenizerFast,
+)
+
+from diffusers.image_processor import VaeImageProcessor
+from diffusers.loaders import FluxLoraLoaderMixin
+from diffusers.models.autoencoders import AutoencoderKL
+from diffusers.models.transformers import FluxTransformer2DModel
+from diffusers.schedulers import FlowMatchEulerDiscreteScheduler
+from diffusers.utils import (
+ USE_PEFT_BACKEND,
+ is_torch_xla_available,
+ logging,
+ replace_example_docstring,
+ scale_lora_layers,
+ unscale_lora_layers,
+)
+from diffusers.utils.torch_utils import randn_tensor
+from diffusers.pipelines.pipeline_utils import DiffusionPipeline
+
+
+if is_torch_xla_available():
+ import torch_xla.core.xla_model as xm
+
+ XLA_AVAILABLE = True
+else:
+ XLA_AVAILABLE = False
+
+
+logger = logging.get_logger(__name__) # pylint: disable=invalid-name
+
+EXAMPLE_DOC_STRING = """
+ Examples:
+ ```py
+ >>> import torch
+ >>> from diffusers import FluxPipeline
+
+ >>> pipe = FluxPipeline.from_pretrained("black-forest-labs/FLUX.1-schnell", torch_dtype=torch.bfloat16)
+ >>> pipe.to("cuda")
+ >>> prompt = "A cat holding a sign that says hello world"
+ >>> # Depending on the variant being used, the pipeline call will slightly vary.
+ >>> # Refer to the pipeline documentation for more details.
+ >>> image = pipe(prompt, num_inference_steps=4, guidance_scale=0.0).images[0]
+ >>> image.save("flux.png")
+ ```
+"""
+
+
+def calculate_shift(
+ image_seq_len,
+ base_seq_len: int = 256,
+ max_seq_len: int = 4096,
+ base_shift: float = 0.5,
+ max_shift: float = 1.16,
+):
+ m = (max_shift - base_shift) / (max_seq_len - base_seq_len)
+ b = base_shift - m * base_seq_len
+ mu = image_seq_len * m + b
+ return mu
+
+
+# Copied from diffusers.pipelines.stable_diffusion.pipeline_stable_diffusion.retrieve_timesteps
+def retrieve_timesteps(
+ scheduler,
+ num_inference_steps: Optional[int] = None,
+ device: Optional[Union[str, torch.device]] = None,
+ timesteps: Optional[List[int]] = None,
+ sigmas: Optional[List[float]] = None,
+ **kwargs,
+):
+ """
+ Calls the scheduler's `set_timesteps` method and retrieves timesteps from the scheduler after the call. Handles
+ custom timesteps. Any kwargs will be supplied to `scheduler.set_timesteps`.
+
+ Args:
+ scheduler (`SchedulerMixin`):
+ The scheduler to get timesteps from.
+ num_inference_steps (`int`):
+ The number of diffusion steps used when generating samples with a pre-trained model. If used, `timesteps`
+ must be `None`.
+ device (`str` or `torch.device`, *optional*):
+ The device to which the timesteps should be moved to. If `None`, the timesteps are not moved.
+ timesteps (`List[int]`, *optional*):
+ Custom timesteps used to override the timestep spacing strategy of the scheduler. If `timesteps` is passed,
+ `num_inference_steps` and `sigmas` must be `None`.
+ sigmas (`List[float]`, *optional*):
+ Custom sigmas used to override the timestep spacing strategy of the scheduler. If `sigmas` is passed,
+ `num_inference_steps` and `timesteps` must be `None`.
+
+ Returns:
+ `Tuple[torch.Tensor, int]`: A tuple where the first element is the timestep schedule from the scheduler and the
+ second element is the number of inference steps.
+ """
+ if timesteps is not None and sigmas is not None:
+ raise ValueError(
+ "Only one of `timesteps` or `sigmas` can be passed. Please choose one to set custom values"
+ )
+ if timesteps is not None:
+ accepts_timesteps = "timesteps" in set(
+ inspect.signature(scheduler.set_timesteps).parameters.keys()
+ )
+ if not accepts_timesteps:
+ raise ValueError(
+ f"The current scheduler class {scheduler.__class__}'s `set_timesteps` does not support custom"
+ f" timestep schedules. Please check whether you are using the correct scheduler."
+ )
+ scheduler.set_timesteps(timesteps=timesteps, device=device, **kwargs)
+ timesteps = scheduler.timesteps
+ num_inference_steps = len(timesteps)
+ elif sigmas is not None:
+ accept_sigmas = "sigmas" in set(
+ inspect.signature(scheduler.set_timesteps).parameters.keys()
+ )
+ if not accept_sigmas:
+ raise ValueError(
+ f"The current scheduler class {scheduler.__class__}'s `set_timesteps` does not support custom"
+ f" sigmas schedules. Please check whether you are using the correct scheduler."
+ )
+ scheduler.set_timesteps(sigmas=sigmas, device=device, **kwargs)
+ timesteps = scheduler.timesteps
+ num_inference_steps = len(timesteps)
+ else:
+ scheduler.set_timesteps(num_inference_steps, device=device, **kwargs)
+ timesteps = scheduler.timesteps
+ return timesteps, num_inference_steps
+
+
+class FluxPipeline(DiffusionPipeline, FluxLoraLoaderMixin):
+ r"""
+ The Flux pipeline for text-to-image generation.
+
+ Reference: https://blackforestlabs.ai/announcing-black-forest-labs/
+
+ Args:
+ transformer ([`FluxTransformer2DModel`]):
+ Conditional Transformer (MMDiT) architecture to denoise the encoded image latents.
+ scheduler ([`FlowMatchEulerDiscreteScheduler`]):
+ A scheduler to be used in combination with `transformer` to denoise the encoded image latents.
+ vae ([`AutoencoderKL`]):
+ Variational Auto-Encoder (VAE) Model to encode and decode images to and from latent representations.
+ text_encoder ([`CLIPTextModelWithProjection`]):
+ [CLIP](https://huggingface.co/docs/transformers/model_doc/clip#transformers.CLIPTextModelWithProjection),
+ specifically the [clip-vit-large-patch14](https://huggingface.co/openai/clip-vit-large-patch14) variant,
+ with an additional added projection layer that is initialized with a diagonal matrix with the `hidden_size`
+ as its dimension.
+ text_encoder_2 ([`CLIPTextModelWithProjection`]):
+ [CLIP](https://huggingface.co/docs/transformers/model_doc/clip#transformers.CLIPTextModelWithProjection),
+ specifically the
+ [laion/CLIP-ViT-bigG-14-laion2B-39B-b160k](https://huggingface.co/laion/CLIP-ViT-bigG-14-laion2B-39B-b160k)
+ variant.
+ tokenizer (`CLIPTokenizer`):
+ Tokenizer of class
+ [CLIPTokenizer](https://huggingface.co/docs/transformers/v4.21.0/en/model_doc/clip#transformers.CLIPTokenizer).
+ tokenizer_2 (`CLIPTokenizer`):
+ Second Tokenizer of class
+ [CLIPTokenizer](https://huggingface.co/docs/transformers/v4.21.0/en/model_doc/clip#transformers.CLIPTokenizer).
+ """
+
+ model_cpu_offload_seq = "text_encoder->text_encoder_2->transformer->vae"
+ _optional_components = []
+ _callback_tensor_inputs = ["latents", "prompt_embeds"]
+
+ def __init__(
+ self,
+ scheduler: FlowMatchEulerDiscreteScheduler,
+ vae: AutoencoderKL,
+ text_encoder: CLIPTextModel,
+ tokenizer: CLIPTokenizer,
+ text_encoder_2: T5EncoderModel,
+ tokenizer_2: T5TokenizerFast,
+ transformer: FluxTransformer2DModel,
+ ):
+ super().__init__()
+
+ self.register_modules(
+ vae=vae,
+ text_encoder=text_encoder,
+ text_encoder_2=text_encoder_2,
+ tokenizer=tokenizer,
+ tokenizer_2=tokenizer_2,
+ transformer=transformer,
+ scheduler=scheduler,
+ )
+ self.vae_scale_factor = (
+ 2 ** (len(self.vae.config.block_out_channels))
+ if hasattr(self, "vae") and self.vae is not None
+ else 16
+ )
+ self.image_processor = VaeImageProcessor(vae_scale_factor=self.vae_scale_factor)
+ self.tokenizer_max_length = (
+ self.tokenizer.model_max_length
+ if hasattr(self, "tokenizer") and self.tokenizer is not None
+ else 77
+ )
+ self.default_sample_size = 64
+
+ def _get_t5_prompt_embeds(
+ self,
+ prompt: Union[str, List[str]] = None,
+ num_images_per_prompt: int = 1,
+ max_sequence_length: int = 512,
+ device: Optional[torch.device] = None,
+ dtype: Optional[torch.dtype] = None,
+ ):
+ device = device or self._execution_device
+ dtype = dtype or self.text_encoder.dtype
+
+ prompt = [prompt] if isinstance(prompt, str) else prompt
+ batch_size = len(prompt)
+
+ text_inputs = self.tokenizer_2(
+ prompt,
+ padding="max_length",
+ max_length=max_sequence_length,
+ truncation=True,
+ return_length=False,
+ return_overflowing_tokens=False,
+ return_tensors="pt",
+ )
+ prompt_attention_mask = text_inputs.attention_mask
+ text_input_ids = text_inputs.input_ids
+ untruncated_ids = self.tokenizer_2(
+ prompt, padding="longest", return_tensors="pt"
+ ).input_ids
+
+ if untruncated_ids.shape[-1] >= text_input_ids.shape[-1] and not torch.equal(
+ text_input_ids, untruncated_ids
+ ):
+ removed_text = self.tokenizer_2.batch_decode(
+ untruncated_ids[:, self.tokenizer_max_length - 1 : -1]
+ )
+ # logger.warning(
+ # "The following part of your input was truncated because `max_sequence_length` is set to "
+ # f" {max_sequence_length} tokens: {removed_text}"
+ # )
+
+ prompt_embeds = self.text_encoder_2(
+ text_input_ids.to(device), output_hidden_states=False
+ )[0]
+
+ dtype = self.text_encoder_2.dtype
+ prompt_embeds = prompt_embeds.to(dtype=dtype, device=device)
+
+ _, seq_len, _ = prompt_embeds.shape
+
+ # duplicate text embeddings and attention mask for each generation per prompt, using mps friendly method
+ prompt_embeds = prompt_embeds.repeat(1, num_images_per_prompt, 1)
+ prompt_embeds = prompt_embeds.view(
+ batch_size * num_images_per_prompt, seq_len, -1
+ )
+
+ return prompt_embeds, prompt_attention_mask
+
+ def _get_clip_prompt_embeds(
+ self,
+ prompt: Union[str, List[str]],
+ num_images_per_prompt: int = 1,
+ device: Optional[torch.device] = None,
+ ):
+ device = device or self._execution_device
+
+ prompt = [prompt] if isinstance(prompt, str) else prompt
+ batch_size = len(prompt)
+
+ text_inputs = self.tokenizer(
+ prompt,
+ padding="max_length",
+ max_length=self.tokenizer_max_length,
+ truncation=True,
+ return_overflowing_tokens=False,
+ return_length=False,
+ return_tensors="pt",
+ )
+
+ text_input_ids = text_inputs.input_ids
+ untruncated_ids = self.tokenizer(
+ prompt, padding="longest", return_tensors="pt"
+ ).input_ids
+ if untruncated_ids.shape[-1] >= text_input_ids.shape[-1] and not torch.equal(
+ text_input_ids, untruncated_ids
+ ):
+ removed_text = self.tokenizer.batch_decode(
+ untruncated_ids[:, self.tokenizer_max_length - 1 : -1]
+ )
+ # logger.warning(
+ # "The following part of your input was truncated because CLIP can only handle sequences up to"
+ # f" {self.tokenizer_max_length} tokens: {removed_text}"
+ # )
+ prompt_embeds = self.text_encoder(
+ text_input_ids.to(device), output_hidden_states=False
+ )
+
+ # Use pooled output of CLIPTextModel
+ prompt_embeds = prompt_embeds.pooler_output
+ prompt_embeds = prompt_embeds.to(dtype=self.text_encoder.dtype, device=device)
+
+ # duplicate text embeddings for each generation per prompt, using mps friendly method
+ prompt_embeds = prompt_embeds.repeat(1, num_images_per_prompt, 1)
+ prompt_embeds = prompt_embeds.view(batch_size * num_images_per_prompt, -1)
+
+ return prompt_embeds
+
+ def encode_prompt(
+ self,
+ prompt: Union[str, List[str]],
+ prompt_2: Union[str, List[str]],
+ device: Optional[torch.device] = None,
+ num_images_per_prompt: int = 1,
+ prompt_embeds: Optional[torch.FloatTensor] = None,
+ pooled_prompt_embeds: Optional[torch.FloatTensor] = None,
+ max_sequence_length: int = 512,
+ lora_scale: Optional[float] = None,
+ ):
+ r"""
+
+ Args:
+ prompt (`str` or `List[str]`, *optional*):
+ prompt to be encoded
+ prompt_2 (`str` or `List[str]`, *optional*):
+ The prompt or prompts to be sent to the `tokenizer_2` and `text_encoder_2`. If not defined, `prompt` is
+ used in all text-encoders
+ device: (`torch.device`):
+ torch device
+ num_images_per_prompt (`int`):
+ number of images that should be generated per prompt
+ prompt_embeds (`torch.FloatTensor`, *optional*):
+ Pre-generated text embeddings. Can be used to easily tweak text inputs, *e.g.* prompt weighting. If not
+ provided, text embeddings will be generated from `prompt` input argument.
+ pooled_prompt_embeds (`torch.FloatTensor`, *optional*):
+ Pre-generated pooled text embeddings. Can be used to easily tweak text inputs, *e.g.* prompt weighting.
+ If not provided, pooled text embeddings will be generated from `prompt` input argument.
+ clip_skip (`int`, *optional*):
+ Number of layers to be skipped from CLIP while computing the prompt embeddings. A value of 1 means that
+ the output of the pre-final layer will be used for computing the prompt embeddings.
+ lora_scale (`float`, *optional*):
+ A lora scale that will be applied to all LoRA layers of the text encoder if LoRA layers are loaded.
+ """
+ device = device or self._execution_device
+
+ # set lora scale so that monkey patched LoRA
+ # function of text encoder can correctly access it
+ if lora_scale is not None and isinstance(self, FluxLoraLoaderMixin):
+ self._lora_scale = lora_scale
+
+ # dynamically adjust the LoRA scale
+ if self.text_encoder is not None and USE_PEFT_BACKEND:
+ scale_lora_layers(self.text_encoder, lora_scale)
+ if self.text_encoder_2 is not None and USE_PEFT_BACKEND:
+ scale_lora_layers(self.text_encoder_2, lora_scale)
+
+ prompt = [prompt] if isinstance(prompt, str) else prompt
+ if prompt is not None:
+ batch_size = len(prompt)
+ else:
+ batch_size = prompt_embeds.shape[0]
+
+ prompt_attention_mask = None
+ if prompt_embeds is None:
+ prompt_2 = prompt_2 or prompt
+ prompt_2 = [prompt_2] if isinstance(prompt_2, str) else prompt_2
+
+ # We only use the pooled prompt output from the CLIPTextModel
+ pooled_prompt_embeds = self._get_clip_prompt_embeds(
+ prompt=prompt,
+ device=device,
+ num_images_per_prompt=num_images_per_prompt,
+ )
+ prompt_embeds, prompt_attention_mask = self._get_t5_prompt_embeds(
+ prompt=prompt_2,
+ num_images_per_prompt=num_images_per_prompt,
+ max_sequence_length=max_sequence_length,
+ device=device,
+ )
+
+ if self.text_encoder is not None:
+ if isinstance(self, FluxLoraLoaderMixin) and USE_PEFT_BACKEND:
+ # Retrieve the original scale by scaling back the LoRA layers
+ unscale_lora_layers(self.text_encoder, lora_scale)
+
+ if self.text_encoder_2 is not None:
+ if isinstance(self, FluxLoraLoaderMixin) and USE_PEFT_BACKEND:
+ # Retrieve the original scale by scaling back the LoRA layers
+ unscale_lora_layers(self.text_encoder_2, lora_scale)
+
+ text_ids = torch.zeros(batch_size, prompt_embeds.shape[1], 3).to(
+ device=device, dtype=prompt_embeds.dtype
+ )
+
+ return prompt_embeds, pooled_prompt_embeds, text_ids, prompt_attention_mask
+
+ def check_inputs(
+ self,
+ prompt,
+ prompt_2,
+ height,
+ width,
+ prompt_embeds=None,
+ pooled_prompt_embeds=None,
+ callback_on_step_end_tensor_inputs=None,
+ max_sequence_length=None,
+ ):
+ if height % 8 != 0 or width % 8 != 0:
+ raise ValueError(
+ f"`height` and `width` have to be divisible by 8 but are {height} and {width}."
+ )
+
+ if callback_on_step_end_tensor_inputs is not None and not all(
+ k in self._callback_tensor_inputs
+ for k in callback_on_step_end_tensor_inputs
+ ):
+ raise ValueError(
+ f"`callback_on_step_end_tensor_inputs` has to be in {self._callback_tensor_inputs}, but found {[k for k in callback_on_step_end_tensor_inputs if k not in self._callback_tensor_inputs]}"
+ )
+
+ if prompt is not None and prompt_embeds is not None:
+ raise ValueError(
+ f"Cannot forward both `prompt`: {prompt} and `prompt_embeds`: {prompt_embeds}. Please make sure to"
+ " only forward one of the two."
+ )
+ elif prompt_2 is not None and prompt_embeds is not None:
+ raise ValueError(
+ f"Cannot forward both `prompt_2`: {prompt_2} and `prompt_embeds`: {prompt_embeds}. Please make sure to"
+ " only forward one of the two."
+ )
+ elif prompt is None and prompt_embeds is None:
+ raise ValueError(
+ "Provide either `prompt` or `prompt_embeds`. Cannot leave both `prompt` and `prompt_embeds` undefined."
+ )
+ elif prompt is not None and (
+ not isinstance(prompt, str) and not isinstance(prompt, list)
+ ):
+ raise ValueError(
+ f"`prompt` has to be of type `str` or `list` but is {type(prompt)}"
+ )
+ elif prompt_2 is not None and (
+ not isinstance(prompt_2, str) and not isinstance(prompt_2, list)
+ ):
+ raise ValueError(
+ f"`prompt_2` has to be of type `str` or `list` but is {type(prompt_2)}"
+ )
+
+ if prompt_embeds is not None and pooled_prompt_embeds is None:
+ raise ValueError(
+ "If `prompt_embeds` are provided, `pooled_prompt_embeds` also have to be passed. Make sure to generate `pooled_prompt_embeds` from the same text encoder that was used to generate `prompt_embeds`."
+ )
+
+ if max_sequence_length is not None and max_sequence_length > 512:
+ raise ValueError(
+ f"`max_sequence_length` cannot be greater than 512 but is {max_sequence_length}"
+ )
+
+ @staticmethod
+ def _prepare_latent_image_ids(batch_size, height, width, device, dtype):
+ latent_image_ids = torch.zeros(height // 2, width // 2, 3)
+ latent_image_ids[..., 1] = (
+ latent_image_ids[..., 1] + torch.arange(height // 2)[:, None]
+ )
+ latent_image_ids[..., 2] = (
+ latent_image_ids[..., 2] + torch.arange(width // 2)[None, :]
+ )
+
+ latent_image_id_height, latent_image_id_width, latent_image_id_channels = (
+ latent_image_ids.shape
+ )
+
+ latent_image_ids = latent_image_ids[None, :].repeat(batch_size, 1, 1, 1)
+ latent_image_ids = latent_image_ids.reshape(
+ batch_size,
+ latent_image_id_height * latent_image_id_width,
+ latent_image_id_channels,
+ )
+
+ return latent_image_ids.to(device=device, dtype=dtype)
+
+ @staticmethod
+ def _pack_latents(latents, batch_size, num_channels_latents, height, width):
+ latents = latents.view(
+ batch_size, num_channels_latents, height // 2, 2, width // 2, 2
+ )
+ latents = latents.permute(0, 2, 4, 1, 3, 5)
+ latents = latents.reshape(
+ batch_size, (height // 2) * (width // 2), num_channels_latents * 4
+ )
+
+ return latents
+
+ @staticmethod
+ def _unpack_latents(latents, height, width, vae_scale_factor):
+ batch_size, num_patches, channels = latents.shape
+
+ height = height // vae_scale_factor
+ width = width // vae_scale_factor
+
+ latents = latents.view(batch_size, height, width, channels // 4, 2, 2)
+ latents = latents.permute(0, 3, 1, 4, 2, 5)
+
+ latents = latents.reshape(
+ batch_size, channels // (2 * 2), height * 2, width * 2
+ )
+
+ return latents
+
+ def prepare_latents(
+ self,
+ batch_size,
+ num_channels_latents,
+ height,
+ width,
+ dtype,
+ device,
+ generator,
+ latents=None,
+ ):
+ height = 2 * (int(height) // self.vae_scale_factor)
+ width = 2 * (int(width) // self.vae_scale_factor)
+
+ shape = (batch_size, num_channels_latents, height, width)
+
+ if latents is not None:
+ latent_image_ids = self._prepare_latent_image_ids(
+ batch_size, height, width, device, dtype
+ )
+ return latents.to(device=device, dtype=dtype), latent_image_ids
+
+ if isinstance(generator, list) and len(generator) != batch_size:
+ raise ValueError(
+ f"You have passed a list of generators of length {len(generator)}, but requested an effective batch"
+ f" size of {batch_size}. Make sure the batch size matches the length of the generators."
+ )
+
+ latents = randn_tensor(shape, generator=generator, device=device, dtype=dtype)
+ latents = self._pack_latents(
+ latents, batch_size, num_channels_latents, height, width
+ )
+
+ latent_image_ids = self._prepare_latent_image_ids(
+ batch_size, height, width, device, dtype
+ )
+
+ return latents, latent_image_ids
+
+ @property
+ def guidance_scale(self):
+ return self._guidance_scale
+
+ @property
+ def joint_attention_kwargs(self):
+ return self._joint_attention_kwargs
+
+ @property
+ def num_timesteps(self):
+ return self._num_timesteps
+
+ @property
+ def interrupt(self):
+ return self._interrupt
+
+ @torch.no_grad()
+ @replace_example_docstring(EXAMPLE_DOC_STRING)
+ def __call__(
+ self,
+ prompt: Union[str, List[str]] = None,
+ prompt_mask: Optional[Union[torch.FloatTensor, List[torch.FloatTensor]]] = None,
+ negative_mask: Optional[
+ Union[torch.FloatTensor, List[torch.FloatTensor]]
+ ] = None,
+ prompt_2: Optional[Union[str, List[str]]] = None,
+ height: Optional[int] = None,
+ width: Optional[int] = None,
+ num_inference_steps: int = 28,
+ timesteps: List[int] = None,
+ guidance_scale: float = 3.5,
+ num_images_per_prompt: Optional[int] = 1,
+ generator: Optional[Union[torch.Generator, List[torch.Generator]]] = None,
+ latents: Optional[torch.FloatTensor] = None,
+ prompt_embeds: Optional[torch.FloatTensor] = None,
+ pooled_prompt_embeds: Optional[torch.FloatTensor] = None,
+ output_type: Optional[str] = "pil",
+ return_dict: bool = True,
+ joint_attention_kwargs: Optional[Dict[str, Any]] = None,
+ callback_on_step_end: Optional[Callable[[int, int, Dict], None]] = None,
+ callback_on_step_end_tensor_inputs: List[str] = ["latents"],
+ max_sequence_length: int = 512,
+ guidance_scale_real: float = 1.0,
+ negative_prompt: Union[str, List[str]] = "",
+ negative_prompt_2: Union[str, List[str]] = "",
+ negative_prompt_embeds: Optional[torch.FloatTensor] = None,
+ negative_pooled_prompt_embeds: Optional[torch.FloatTensor] = None,
+ no_cfg_until_timestep: int = 2,
+ ):
+ r"""
+ Function invoked when calling the pipeline for generation.
+
+ Args:
+ prompt (`str` or `List[str]`, *optional*):
+ The prompt or prompts to guide the image generation. If not defined, one has to pass `prompt_embeds`.
+ instead.
+ prompt_mask (`str` or `List[str]`, *optional*):
+ The prompt or prompts to be used as a mask for the image generation. If not defined, `prompt` is used
+ instead.
+ prompt_2 (`str` or `List[str]`, *optional*):
+ The prompt or prompts to be sent to `tokenizer_2` and `text_encoder_2`. If not defined, `prompt` is
+ will be used instead
+ height (`int`, *optional*, defaults to self.unet.config.sample_size * self.vae_scale_factor):
+ The height in pixels of the generated image. This is set to 1024 by default for the best results.
+ width (`int`, *optional*, defaults to self.unet.config.sample_size * self.vae_scale_factor):
+ The width in pixels of the generated image. This is set to 1024 by default for the best results.
+ num_inference_steps (`int`, *optional*, defaults to 50):
+ The number of denoising steps. More denoising steps usually lead to a higher quality image at the
+ expense of slower inference.
+ timesteps (`List[int]`, *optional*):
+ Custom timesteps to use for the denoising process with schedulers which support a `timesteps` argument
+ in their `set_timesteps` method. If not defined, the default behavior when `num_inference_steps` is
+ passed will be used. Must be in descending order.
+ guidance_scale (`float`, *optional*, defaults to 7.0):
+ Guidance scale as defined in [Classifier-Free Diffusion Guidance](https://arxiv.org/abs/2207.12598).
+ `guidance_scale` is defined as `w` of equation 2. of [Imagen
+ Paper](https://arxiv.org/pdf/2205.11487.pdf). Guidance scale is enabled by setting `guidance_scale >
+ 1`. Higher guidance scale encourages to generate images that are closely linked to the text `prompt`,
+ usually at the expense of lower image quality.
+ num_images_per_prompt (`int`, *optional*, defaults to 1):
+ The number of images to generate per prompt.
+ generator (`torch.Generator` or `List[torch.Generator]`, *optional*):
+ One or a list of [torch generator(s)](https://pytorch.org/docs/stable/generated/torch.Generator.html)
+ to make generation deterministic.
+ latents (`torch.FloatTensor`, *optional*):
+ Pre-generated noisy latents, sampled from a Gaussian distribution, to be used as inputs for image
+ generation. Can be used to tweak the same generation with different prompts. If not provided, a latents
+ tensor will ge generated by sampling using the supplied random `generator`.
+ prompt_embeds (`torch.FloatTensor`, *optional*):
+ Pre-generated text embeddings. Can be used to easily tweak text inputs, *e.g.* prompt weighting. If not
+ provided, text embeddings will be generated from `prompt` input argument.
+ pooled_prompt_embeds (`torch.FloatTensor`, *optional*):
+ Pre-generated pooled text embeddings. Can be used to easily tweak text inputs, *e.g.* prompt weighting.
+ If not provided, pooled text embeddings will be generated from `prompt` input argument.
+ output_type (`str`, *optional*, defaults to `"pil"`):
+ The output format of the generate image. Choose between
+ [PIL](https://pillow.readthedocs.io/en/stable/): `PIL.Image.Image` or `np.array`.
+ return_dict (`bool`, *optional*, defaults to `True`):
+ Whether or not to return a [`~pipelines.flux.FluxPipelineOutput`] instead of a plain tuple.
+ 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).
+ callback_on_step_end (`Callable`, *optional*):
+ A function that calls at the end of each denoising steps during the inference. The function is called
+ with the following arguments: `callback_on_step_end(self: DiffusionPipeline, step: int, timestep: int,
+ callback_kwargs: Dict)`. `callback_kwargs` will include a list of all tensors as specified by
+ `callback_on_step_end_tensor_inputs`.
+ callback_on_step_end_tensor_inputs (`List`, *optional*):
+ The list of tensor inputs for the `callback_on_step_end` function. The tensors specified in the list
+ will be passed as `callback_kwargs` argument. You will only be able to include variables listed in the
+ `._callback_tensor_inputs` attribute of your pipeline class.
+ max_sequence_length (`int` defaults to 512): Maximum sequence length to use with the `prompt`.
+
+ Examples:
+
+ Returns:
+ [`~pipelines.flux.FluxPipelineOutput`] or `tuple`: [`~pipelines.flux.FluxPipelineOutput`] if `return_dict`
+ is True, otherwise a `tuple`. When returning a tuple, the first element is a list with the generated
+ images.
+ """
+
+ height = height or self.default_sample_size * self.vae_scale_factor
+ width = width or self.default_sample_size * self.vae_scale_factor
+
+ # 1. Check inputs. Raise error if not correct
+ self.check_inputs(
+ prompt,
+ prompt_2,
+ height,
+ width,
+ prompt_embeds=prompt_embeds,
+ pooled_prompt_embeds=pooled_prompt_embeds,
+ callback_on_step_end_tensor_inputs=callback_on_step_end_tensor_inputs,
+ max_sequence_length=max_sequence_length,
+ )
+
+ self._guidance_scale = guidance_scale
+ self._guidance_scale_real = guidance_scale_real
+ self._joint_attention_kwargs = joint_attention_kwargs
+ self._interrupt = False
+
+ # 2. Define call parameters
+ if prompt is not None and isinstance(prompt, str):
+ batch_size = 1
+ elif prompt is not None and isinstance(prompt, list):
+ batch_size = len(prompt)
+ else:
+ batch_size = prompt_embeds.shape[0]
+
+ device = self._execution_device
+
+ lora_scale = (
+ self.joint_attention_kwargs.get("scale", None)
+ if self.joint_attention_kwargs is not None
+ else None
+ )
+ (
+ prompt_embeds,
+ pooled_prompt_embeds,
+ text_ids,
+ _,
+ ) = self.encode_prompt(
+ prompt=prompt,
+ prompt_2=prompt_2,
+ prompt_embeds=prompt_embeds,
+ pooled_prompt_embeds=pooled_prompt_embeds,
+ device=device,
+ num_images_per_prompt=num_images_per_prompt,
+ max_sequence_length=max_sequence_length,
+ lora_scale=lora_scale,
+ )
+
+ if negative_prompt_2 == "" and negative_prompt != "":
+ negative_prompt_2 = negative_prompt
+
+ negative_text_ids = text_ids
+ if guidance_scale_real > 1.0 and (
+ negative_prompt_embeds is None or negative_pooled_prompt_embeds is None
+ ):
+ (
+ negative_prompt_embeds,
+ negative_pooled_prompt_embeds,
+ negative_text_ids,
+ _,
+ ) = self.encode_prompt(
+ prompt=negative_prompt,
+ prompt_2=negative_prompt_2,
+ prompt_embeds=None,
+ pooled_prompt_embeds=None,
+ device=device,
+ num_images_per_prompt=num_images_per_prompt,
+ max_sequence_length=max_sequence_length,
+ lora_scale=lora_scale,
+ )
+
+ # 4. Prepare latent variables
+ num_channels_latents = self.transformer.config.in_channels // 4
+ latents, latent_image_ids = self.prepare_latents(
+ batch_size * num_images_per_prompt,
+ num_channels_latents,
+ height,
+ width,
+ prompt_embeds.dtype,
+ device,
+ generator,
+ latents,
+ )
+
+ # 5. Prepare timesteps
+ sigmas = np.linspace(1.0, 1 / num_inference_steps, num_inference_steps)
+ image_seq_len = latents.shape[1]
+ mu = calculate_shift(
+ image_seq_len,
+ self.scheduler.config.base_image_seq_len,
+ self.scheduler.config.max_image_seq_len,
+ self.scheduler.config.base_shift,
+ self.scheduler.config.max_shift,
+ )
+ timesteps, num_inference_steps = retrieve_timesteps(
+ self.scheduler,
+ num_inference_steps,
+ device,
+ timesteps,
+ sigmas,
+ mu=mu,
+ )
+ num_warmup_steps = max(
+ len(timesteps) - num_inference_steps * self.scheduler.order, 0
+ )
+ self._num_timesteps = len(timesteps)
+
+ latents = latents.to(self.transformer.device)
+ latent_image_ids = latent_image_ids.to(self.transformer.device)[0]
+ timesteps = timesteps.to(self.transformer.device)
+ text_ids = text_ids.to(self.transformer.device)[0]
+
+ # 6. Denoising loop
+ with self.progress_bar(total=num_inference_steps) as progress_bar:
+ for i, t in enumerate(timesteps):
+ if self.interrupt:
+ continue
+
+ # broadcast to batch dimension in a way that's compatible with ONNX/Core ML
+ timestep = t.expand(latents.shape[0]).to(latents.dtype)
+
+ # handle guidance
+ if self.transformer.config.guidance_embeds:
+ guidance = torch.tensor(
+ [guidance_scale], device=self.transformer.device
+ )
+ guidance = guidance.expand(latents.shape[0])
+ else:
+ guidance = None
+
+ extra_transformer_args = {}
+ if prompt_mask is not None:
+ extra_transformer_args["attention_mask"] = prompt_mask.to(
+ device=self.transformer.device
+ )
+
+ noise_pred = self.transformer(
+ hidden_states=latents.to(
+ device=self.transformer.device # , dtype=self.transformer.dtype # can't cast dtype like this because of NF4
+ ),
+ # YiYi notes: divide it by 1000 for now because we scale it by 1000 in the transforme rmodel (we should not keep it but I want to keep the inputs same for the model for testing)
+ timestep=timestep / 1000,
+ guidance=guidance,
+ pooled_projections=pooled_prompt_embeds.to(
+ device=self.transformer.device # , dtype=self.transformer.dtype # can't cast dtype like this because of NF4
+ ),
+ encoder_hidden_states=prompt_embeds.to(
+ device=self.transformer.device # , dtype=self.transformer.dtype # can't cast dtype like this because of NF4
+ ),
+ txt_ids=text_ids,
+ img_ids=latent_image_ids,
+ joint_attention_kwargs=self.joint_attention_kwargs,
+ return_dict=False,
+ **extra_transformer_args,
+ )[0]
+
+ # TODO optionally use batch prediction to speed this up.
+ if guidance_scale_real > 1.0 and i >= no_cfg_until_timestep:
+ noise_pred_uncond = self.transformer(
+ hidden_states=latents.to(
+ device=self.transformer.device # , dtype=self.transformer.dtype # can't cast dtype like this because of NF4
+ ),
+ # YiYi notes: divide it by 1000 for now because we scale it by 1000 in the transforme rmodel (we should not keep it but I want to keep the inputs same for the model for testing)
+ timestep=timestep / 1000,
+ guidance=guidance,
+ pooled_projections=negative_pooled_prompt_embeds.to(
+ device=self.transformer.device # , dtype=self.transformer.dtype # can't cast dtype like this because of NF4
+ ),
+ encoder_hidden_states=negative_prompt_embeds.to(
+ device=self.transformer.device # , dtype=self.transformer.dtype # can't cast dtype like this because of NF4
+ ),
+ txt_ids=negative_text_ids.to(device=self.transformer.device),
+ img_ids=latent_image_ids.to(device=self.transformer.device),
+ joint_attention_kwargs=self.joint_attention_kwargs,
+ return_dict=False,
+ )[0]
+
+ noise_pred = noise_pred_uncond + guidance_scale_real * (
+ noise_pred - noise_pred_uncond
+ )
+
+ # compute the previous noisy sample x_t -> x_t-1
+ latents_dtype = latents.dtype
+ latents = self.scheduler.step(
+ noise_pred, t, latents, return_dict=False
+ )[0]
+
+ if latents.dtype != latents_dtype:
+ if torch.backends.mps.is_available():
+ # some platforms (eg. apple mps) misbehave due to a pytorch bug: https://github.com/pytorch/pytorch/pull/99272
+ latents = latents.to(latents_dtype)
+
+ if callback_on_step_end is not None:
+ callback_kwargs = {}
+ for k in callback_on_step_end_tensor_inputs:
+ callback_kwargs[k] = locals()[k]
+ callback_outputs = callback_on_step_end(self, i, t, callback_kwargs)
+
+ latents = callback_outputs.pop("latents", latents)
+ prompt_embeds = callback_outputs.pop("prompt_embeds", prompt_embeds)
+
+ # call the callback, if provided
+ if i == len(timesteps) - 1 or (
+ (i + 1) > num_warmup_steps and (i + 1) % self.scheduler.order == 0
+ ):
+ progress_bar.update()
+
+ if XLA_AVAILABLE:
+ xm.mark_step()
+
+ if output_type == "latent":
+ image = latents
+
+ else:
+ latents = self._unpack_latents(
+ latents, height, width, self.vae_scale_factor
+ )
+ latents = (
+ latents / self.vae.config.scaling_factor
+ ) + self.vae.config.shift_factor
+
+ image = self.vae.decode(
+ latents.to(device=self.vae.device, dtype=self.vae.dtype),
+ return_dict=False,
+ )[0]
+ image = self.image_processor.postprocess(image, output_type=output_type)
+
+ # Offload all models
+ self.maybe_free_model_hooks()
+
+ if not return_dict:
+ return (image,)
+
+ return FluxPipelineOutput(images=image)
+
+
+from dataclasses import dataclass
+from typing import List, Union
+import PIL.Image
+from diffusers.utils import BaseOutput
+
+
+@dataclass
+class FluxPipelineOutput(BaseOutput):
+ """
+ Output class for Stable Diffusion pipelines.
+
+ Args:
+ images (`List[PIL.Image.Image]` or `np.ndarray`)
+ List of denoised PIL images of length `batch_size` or numpy array of shape `(batch_size, height, width,
+ num_channels)`. PIL images or numpy array present the denoised images of the diffusion pipeline.
+ """
+
+ images: Union[List[PIL.Image.Image], np.ndarray]