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Zero
import torch | |
import numpy as np | |
import html | |
import inspect | |
import re | |
import urllib.parse as ul | |
from transformers import CLIPTextModel, CLIPTokenizer, T5EncoderModel, T5TokenizerFast, CLIPTextModelWithProjection | |
from diffusers import FlowMatchEulerDiscreteScheduler, AutoPipelineForImage2Image, FluxPipeline, FluxTransformer2DModel | |
from diffusers import StableDiffusion3Pipeline, AutoencoderKL, DiffusionPipeline, ImagePipelineOutput | |
from diffusers.image_processor import VaeImageProcessor | |
from diffusers.loaders import FluxLoraLoaderMixin, FromSingleFileMixin, SD3LoraLoaderMixin | |
from diffusers.utils import ( | |
USE_PEFT_BACKEND, | |
is_torch_xla_available, | |
logging, | |
BACKENDS_MAPPING, | |
deprecate, | |
replace_example_docstring, | |
scale_lora_layers, | |
unscale_lora_layers, | |
) | |
from diffusers.utils.torch_utils import randn_tensor | |
from diffusers.pipelines.flux.pipeline_output import FluxPipelineOutput | |
from typing import Any, Callable, Dict, List, Optional, Union | |
from PIL import Image | |
from diffusers.pipelines.flux.pipeline_flux import calculate_shift, retrieve_timesteps, FluxTransformer2DModel | |
from diffusers.utils import is_torch_xla_available | |
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 | |
# Constants for shift calculation | |
BASE_SEQ_LEN = 256 | |
MAX_SEQ_LEN = 4096 | |
BASE_SHIFT = 0.5 | |
MAX_SHIFT = 1.16 | |
# Helper functions | |
def calculate_timestep_shift(image_seq_len: int) -> float: | |
"""Calculates the timestep shift (mu) based on the image sequence length.""" | |
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 | |
def prepare_timesteps( | |
scheduler: FlowMatchEulerDiscreteScheduler, | |
num_inference_steps: Optional[int] = None, | |
device: Optional[Union[str, torch.device]] = None, | |
timesteps: Optional[List[int]] = None, | |
sigmas: Optional[List[float]] = None, | |
mu: Optional[float] = None, | |
) -> (torch.Tensor, int): | |
"""Prepares the timesteps for the diffusion process.""" | |
if timesteps is not None and sigmas is not None: | |
raise ValueError("Only one of `timesteps` or `sigmas` can be passed.") | |
if timesteps is not None: | |
scheduler.set_timesteps(timesteps=timesteps, device=device) | |
elif sigmas is not None: | |
scheduler.set_timesteps(sigmas=sigmas, device=device) | |
else: | |
scheduler.set_timesteps(num_inference_steps, device=device, mu=mu) | |
timesteps = scheduler.timesteps | |
num_inference_steps = len(timesteps) | |
return timesteps, num_inference_steps | |
# FLUX pipeline function | |
class FluxWithCFGPipeline(DiffusionPipeline, FluxLoraLoaderMixin, FromSingleFileMixin): | |
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=True, | |
return_overflowing_tokens=True, | |
return_tensors="pt", | |
) | |
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 | |
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) | |
_, seq_len = prompt_embeds.shape | |
# 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, seq_len, -1) | |
return prompt_embeds | |
def encode_prompt( | |
self, | |
prompt: Union[str, List[str]], | |
prompt_2: Union[str, List[str]], | |
num_images_per_prompt: int = 1, | |
max_sequence_length: int = 512, | |
do_classifier_free_guidance: bool = True, | |
device: Optional[torch.device] = None, | |
negative_prompt: Optional[Union[str, List[str]]] = None, | |
negative_prompt_2: Optional[Union[str, List[str]]] = None, | |
prompt_embeds: Optional[torch.FloatTensor] = None, | |
negative_prompt_embeds: Optional[torch.Tensor] = None, | |
pooled_prompt_embeds: Optional[torch.FloatTensor] = None, | |
negative_pooled_prompt_embeds: Optional[torch.FloatTensor] = None, | |
lora_scale: Optional[float] = None, | |
): | |
device = device or self._execution_device | |
if device is None: | |
device = 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] | |
if prompt_embeds is None: | |
prompt_2 = prompt_2 or prompt | |
prompt_2 = [prompt_2] if isinstance(prompt_2, str) else prompt_2 | |
pooled_prompt_embeds = self._get_clip_prompt_embeds( | |
prompt=prompt, | |
device=device, | |
num_images_per_prompt=num_images_per_prompt, | |
) | |
prompt_embeds = 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 do_classifier_free_guidance and negative_prompt_embeds is None: | |
negative_prompt = negative_prompt or "" | |
negative_prompt_2 = negative_prompt_2 or negative_prompt | |
# normalize str to list | |
negative_prompt = batch_size * [negative_prompt] if isinstance(negative_prompt, str) else negative_prompt | |
negative_prompt_2 = ( | |
batch_size * [negative_prompt_2] if isinstance(negative_prompt_2, str) else negative_prompt_2 | |
) | |
if prompt is not None and type(prompt) is not type(negative_prompt): | |
raise TypeError( | |
f"`negative_prompt` should be the same type to `prompt`, but got {type(negative_prompt)} !=" | |
f" {type(prompt)}." | |
) | |
elif batch_size != len(negative_prompt): | |
raise ValueError( | |
f"`negative_prompt`: {negative_prompt} has batch size {len(negative_prompt)}, but `prompt`:" | |
f" {prompt} has batch size {batch_size}. Please make sure that passed `negative_prompt` matches" | |
" the batch size of `prompt`." | |
) | |
negative_pooled_prompt_embeds = self._get_clip_prompt_embeds( | |
prompt=negative_prompt, | |
device=device, | |
num_images_per_prompt=num_images_per_prompt, | |
) | |
negative_prompt_embeds = self._get_t5_prompt_embeds( | |
prompt=negative_prompt_2, | |
device=device, | |
num_images_per_prompt=num_images_per_prompt, | |
max_sequence_length=max_sequence_length, | |
) | |
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) | |
dtype = self.text_encoder.dtype if self.text_encoder is not None else self.transformer.dtype | |
text_ids = torch.zeros(prompt_embeds.shape[1], 3).to(device=device, dtype=dtype) | |
return prompt_embeds, pooled_prompt_embeds, text_ids, negative_prompt_embeds, negative_pooled_prompt_embeds | |
def check_inputs( | |
self, | |
prompt, | |
prompt_2, | |
height, | |
width, | |
prompt_embeds=None, | |
negative_prompt_embeds=None, | |
pooled_prompt_embeds=None, | |
negative_pooled_prompt_embeds=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 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 negative_prompt_embeds is not None and negative_pooled_prompt_embeds is None: | |
raise ValueError("Must provide `negative_pooled_prompt_embeds` when specifying `negative_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}") | |
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) | |
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 | |
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 | |
# Copied from diffusers.pipelines.stable_diffusion.pipeline_stable_diffusion.StableDiffusionPipeline.prepare_extra_step_kwargs | |
def prepare_extra_step_kwargs(self, generator, eta): | |
# prepare extra kwargs for the scheduler step, since not all schedulers have the same signature | |
# eta (η) is only used with the DDIMScheduler, it will be ignored for other schedulers. | |
# eta corresponds to η in DDIM paper: https://arxiv.org/abs/2010.02502 | |
# and should be between [0, 1] | |
accepts_eta = "eta" in set(inspect.signature(self.scheduler.step).parameters.keys()) | |
extra_step_kwargs = {} | |
if accepts_eta: | |
extra_step_kwargs["eta"] = eta | |
# check if the scheduler accepts generator | |
accepts_generator = "generator" in set(inspect.signature(self.scheduler.step).parameters.keys()) | |
if accepts_generator: | |
extra_step_kwargs["generator"] = generator | |
return extra_step_kwargs | |
def enable_vae_slicing(self): | |
r""" | |
Enable sliced VAE decoding. When this option is enabled, the VAE will split the input tensor in slices to | |
compute decoding in several steps. This is useful to save some memory and allow larger batch sizes. | |
""" | |
self.vae.enable_slicing() | |
def disable_vae_slicing(self): | |
r""" | |
Disable sliced VAE decoding. If `enable_vae_slicing` was previously enabled, this method will go back to | |
computing decoding in one step. | |
""" | |
self.vae.disable_slicing() | |
def enable_vae_tiling(self): | |
r""" | |
Enable tiled VAE decoding. When this option is enabled, the VAE will split the input tensor into tiles to | |
compute decoding and encoding in several steps. This is useful for saving a large amount of memory and to allow | |
processing larger images. | |
""" | |
self.vae.enable_tiling() | |
def disable_vae_tiling(self): | |
r""" | |
Disable tiled VAE decoding. If `enable_vae_tiling` was previously enabled, this method will go back to | |
computing decoding in one step. | |
""" | |
self.vae.disable_tiling() | |
def guidance_scale(self): | |
return self._guidance_scale | |
def do_classifier_free_guidance(self): | |
return self._guidance_scale > 1 | |
def joint_attention_kwargs(self): | |
return self._joint_attention_kwargs | |
def num_timesteps(self): | |
return self._num_timesteps | |
def interrupt(self): | |
return self._interrupt | |
def __call__( | |
self, | |
prompt: Union[str, List[str]] = None, | |
prompt_2: Optional[Union[str, List[str]]] = None, | |
negative_prompt: Union[str, List[str]] = None, | |
height: Optional[int] = None, | |
width: Optional[int] = None, | |
num_inference_steps: int = 8, | |
timesteps: List[int] = None, | |
guidance_scale: float = 3.5, | |
device: Optional[int] = None, | |
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", | |
cfg: Optional[bool] = True, | |
return_dict: bool = True, | |
joint_attention_kwargs: Optional[Dict[str, Any]] = None, | |
max_sequence_length: int = 512, | |
): | |
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 | |
self.check_inputs( | |
prompt, | |
prompt_2, | |
height, | |
width, | |
prompt_embeds=prompt_embeds, | |
pooled_prompt_embeds=pooled_prompt_embeds, | |
max_sequence_length=max_sequence_length, | |
) | |
self._guidance_scale = guidance_scale | |
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 = torch.device("cuda:0" if torch.cuda.is_available() else "cpu") | |
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, | |
negative_prompt_embeds, | |
negative_pooled_prompt_embeds | |
) = self.encode_prompt( | |
prompt=prompt, | |
prompt_2=prompt_2, | |
num_images_per_prompt=num_images_per_prompt, | |
max_sequence_length=max_sequence_length, | |
device=device, | |
negative_prompt=negative_prompt, | |
prompt_embeds=prompt_embeds, | |
pooled_prompt_embeds=pooled_prompt_embeds, | |
lora_scale=lora_scale, | |
) | |
if self.do_classifier_free_guidance: | |
prompt_embeds = torch.cat([negative_prompt_embeds, prompt_embeds], dim=0) | |
pooled_prompt_embeds = torch.cat([negative_pooled_prompt_embeds, pooled_prompt_embeds], dim=0) | |
# 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 = prepare_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) | |
# 6. Denoising loop | |
with self.progress_bar(total=num_inference_steps) as progress_bar: | |
for i, t in enumerate(timesteps): | |
if self.interrupt: | |
continue | |
# expand the latents if we are doing classifier free guidance | |
latent_model_input = torch.cat([latents] * 2) if self.do_classifier_free_guidance else latents | |
# broadcast to batch dimension in a way that's compatible with ONNX/Core ML | |
timestep = t.expand(latent_model_input.shape[0]) | |
noise_pred = self.transformer( | |
hidden_states=latent_model_input, | |
timestep=timestep / 1000, | |
pooled_projections=pooled_prompt_embeds, | |
encoder_hidden_states=prompt_embeds, | |
txt_ids=text_ids, | |
img_ids=latent_image_ids, | |
joint_attention_kwargs=self.joint_attention_kwargs, | |
return_dict=False, | |
)[0] | |
if self.do_classifier_free_guidance: | |
noise_pred_uncond, noise_pred_text = noise_pred.chunk(2) | |
noise_pred = noise_pred_uncond + self.guidance_scale * (noise_pred_text - 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) | |
# 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() | |
# Final image | |
return self._decode_latents_to_image(latents, height, width, output_type) | |
self.maybe_free_model_hooks() | |
torch.cuda.empty_cache() | |
def _decode_latents_to_image(self, latents, height, width, output_type, vae=None): | |
"""Decodes the given latents into an image.""" | |
vae = vae or self.vae | |
latents = self._unpack_latents(latents, height, width, self.vae_scale_factor) | |
latents = (latents / vae.config.scaling_factor) + vae.config.shift_factor | |
image = vae.decode(latents, return_dict=False)[0] | |
return self.image_processor.postprocess(image, output_type=output_type)[0] |