Text2Video-Zero
Text2Video-Zero: Text-to-Image Diffusion Models are Zero-Shot Video Generators is by Levon Khachatryan, Andranik Movsisyan, Vahram Tadevosyan, Roberto Henschel, Zhangyang Wang, Shant Navasardyan, Humphrey Shi.
Text2Video-Zero enables zero-shot video generation using either:
- A textual prompt
- A prompt combined with guidance from poses or edges
- Video Instruct-Pix2Pix (instruction-guided video editing)
Results are temporally consistent and closely follow the guidance and textual prompts.
The abstract from the paper is:
Recent text-to-video generation approaches rely on computationally heavy training and require large-scale video datasets. In this paper, we introduce a new task of zero-shot text-to-video generation and propose a low-cost approach (without any training or optimization) by leveraging the power of existing text-to-image synthesis methods (e.g., Stable Diffusion), making them suitable for the video domain. Our key modifications include (i) enriching the latent codes of the generated frames with motion dynamics to keep the global scene and the background time consistent; and (ii) reprogramming frame-level self-attention using a new cross-frame attention of each frame on the first frame, to preserve the context, appearance, and identity of the foreground object. Experiments show that this leads to low overhead, yet high-quality and remarkably consistent video generation. Moreover, our approach is not limited to text-to-video synthesis but is also applicable to other tasks such as conditional and content-specialized video generation, and Video Instruct-Pix2Pix, i.e., instruction-guided video editing. As experiments show, our method performs comparably or sometimes better than recent approaches, despite not being trained on additional video data.
You can find additional information about Text2Video-Zero on the project page, paper, and original codebase.
Usage example
Text-To-Video
To generate a video from prompt, run the following Python code:
import torch
from diffusers import TextToVideoZeroPipeline
import imageio
model_id = "stable-diffusion-v1-5/stable-diffusion-v1-5"
pipe = TextToVideoZeroPipeline.from_pretrained(model_id, torch_dtype=torch.float16).to("cuda")
prompt = "A panda is playing guitar on times square"
result = pipe(prompt=prompt).images
result = [(r * 255).astype("uint8") for r in result]
imageio.mimsave("video.mp4", result, fps=4)
You can change these parameters in the pipeline call:
- Motion field strength (see the paper, Sect. 3.3.1):
motion_field_strength_x
andmotion_field_strength_y
. Default:motion_field_strength_x=12
,motion_field_strength_y=12
T
andT'
(see the paper, Sect. 3.3.1)t0
andt1
in the range{0, ..., num_inference_steps}
. Default:t0=45
,t1=48
- Video length:
video_length
, the number of frames video_length to be generated. Default:video_length=8
We can also generate longer videos by doing the processing in a chunk-by-chunk manner:
import torch
from diffusers import TextToVideoZeroPipeline
import numpy as np
model_id = "stable-diffusion-v1-5/stable-diffusion-v1-5"
pipe = TextToVideoZeroPipeline.from_pretrained(model_id, torch_dtype=torch.float16).to("cuda")
seed = 0
video_length = 24 #24 ÷ 4fps = 6 seconds
chunk_size = 8
prompt = "A panda is playing guitar on times square"
# Generate the video chunk-by-chunk
result = []
chunk_ids = np.arange(0, video_length, chunk_size - 1)
generator = torch.Generator(device="cuda")
for i in range(len(chunk_ids)):
print(f"Processing chunk {i + 1} / {len(chunk_ids)}")
ch_start = chunk_ids[i]
ch_end = video_length if i == len(chunk_ids) - 1 else chunk_ids[i + 1]
# Attach the first frame for Cross Frame Attention
frame_ids = [0] + list(range(ch_start, ch_end))
# Fix the seed for the temporal consistency
generator.manual_seed(seed)
output = pipe(prompt=prompt, video_length=len(frame_ids), generator=generator, frame_ids=frame_ids)
result.append(output.images[1:])
# Concatenate chunks and save
result = np.concatenate(result)
result = [(r * 255).astype("uint8") for r in result]
imageio.mimsave("video.mp4", result, fps=4)
-
SDXL Support
In order to use the SDXL model when generating a video from prompt, use theTextToVideoZeroSDXLPipeline
pipeline:
import torch
from diffusers import TextToVideoZeroSDXLPipeline
model_id = "stabilityai/stable-diffusion-xl-base-1.0"
pipe = TextToVideoZeroSDXLPipeline.from_pretrained(
model_id, torch_dtype=torch.float16, variant="fp16", use_safetensors=True
).to("cuda")
Text-To-Video with Pose Control
To generate a video from prompt with additional pose control
Download a demo video
from huggingface_hub import hf_hub_download filename = "__assets__/poses_skeleton_gifs/dance1_corr.mp4" repo_id = "PAIR/Text2Video-Zero" video_path = hf_hub_download(repo_type="space", repo_id=repo_id, filename=filename)
Read video containing extracted pose images
from PIL import Image import imageio reader = imageio.get_reader(video_path, "ffmpeg") frame_count = 8 pose_images = [Image.fromarray(reader.get_data(i)) for i in range(frame_count)]
To extract pose from actual video, read ControlNet documentation.
Run
StableDiffusionControlNetPipeline
with our custom attention processorimport torch from diffusers import StableDiffusionControlNetPipeline, ControlNetModel from diffusers.pipelines.text_to_video_synthesis.pipeline_text_to_video_zero import CrossFrameAttnProcessor model_id = "stable-diffusion-v1-5/stable-diffusion-v1-5" controlnet = ControlNetModel.from_pretrained("lllyasviel/sd-controlnet-openpose", torch_dtype=torch.float16) pipe = StableDiffusionControlNetPipeline.from_pretrained( model_id, controlnet=controlnet, torch_dtype=torch.float16 ).to("cuda") # Set the attention processor pipe.unet.set_attn_processor(CrossFrameAttnProcessor(batch_size=2)) pipe.controlnet.set_attn_processor(CrossFrameAttnProcessor(batch_size=2)) # fix latents for all frames latents = torch.randn((1, 4, 64, 64), device="cuda", dtype=torch.float16).repeat(len(pose_images), 1, 1, 1) prompt = "Darth Vader dancing in a desert" result = pipe(prompt=[prompt] * len(pose_images), image=pose_images, latents=latents).images imageio.mimsave("video.mp4", result, fps=4)
-
SDXL Support
Since our attention processor also works with SDXL, it can be utilized to generate a video from prompt using ControlNet models powered by SDXL:
import torch from diffusers import StableDiffusionXLControlNetPipeline, ControlNetModel from diffusers.pipelines.text_to_video_synthesis.pipeline_text_to_video_zero import CrossFrameAttnProcessor controlnet_model_id = 'thibaud/controlnet-openpose-sdxl-1.0' model_id = 'stabilityai/stable-diffusion-xl-base-1.0' controlnet = ControlNetModel.from_pretrained(controlnet_model_id, torch_dtype=torch.float16) pipe = StableDiffusionControlNetPipeline.from_pretrained( model_id, controlnet=controlnet, torch_dtype=torch.float16 ).to('cuda') # Set the attention processor pipe.unet.set_attn_processor(CrossFrameAttnProcessor(batch_size=2)) pipe.controlnet.set_attn_processor(CrossFrameAttnProcessor(batch_size=2)) # fix latents for all frames latents = torch.randn((1, 4, 128, 128), device="cuda", dtype=torch.float16).repeat(len(pose_images), 1, 1, 1) prompt = "Darth Vader dancing in a desert" result = pipe(prompt=[prompt] * len(pose_images), image=pose_images, latents=latents).images imageio.mimsave("video.mp4", result, fps=4)
Text-To-Video with Edge Control
To generate a video from prompt with additional Canny edge control, follow the same steps described above for pose-guided generation using Canny edge ControlNet model.
Video Instruct-Pix2Pix
To perform text-guided video editing (with InstructPix2Pix):
Download a demo video
from huggingface_hub import hf_hub_download filename = "__assets__/pix2pix video/camel.mp4" repo_id = "PAIR/Text2Video-Zero" video_path = hf_hub_download(repo_type="space", repo_id=repo_id, filename=filename)
Read video from path
from PIL import Image import imageio reader = imageio.get_reader(video_path, "ffmpeg") frame_count = 8 video = [Image.fromarray(reader.get_data(i)) for i in range(frame_count)]
Run
StableDiffusionInstructPix2PixPipeline
with our custom attention processorimport torch from diffusers import StableDiffusionInstructPix2PixPipeline from diffusers.pipelines.text_to_video_synthesis.pipeline_text_to_video_zero import CrossFrameAttnProcessor model_id = "timbrooks/instruct-pix2pix" pipe = StableDiffusionInstructPix2PixPipeline.from_pretrained(model_id, torch_dtype=torch.float16).to("cuda") pipe.unet.set_attn_processor(CrossFrameAttnProcessor(batch_size=3)) prompt = "make it Van Gogh Starry Night style" result = pipe(prompt=[prompt] * len(video), image=video).images imageio.mimsave("edited_video.mp4", result, fps=4)
DreamBooth specialization
Methods Text-To-Video, Text-To-Video with Pose Control and Text-To-Video with Edge Control can run with custom DreamBooth models, as shown below for Canny edge ControlNet model and Avatar style DreamBooth model:
Download a demo video
from huggingface_hub import hf_hub_download filename = "__assets__/canny_videos_mp4/girl_turning.mp4" repo_id = "PAIR/Text2Video-Zero" video_path = hf_hub_download(repo_type="space", repo_id=repo_id, filename=filename)
Read video from path
from PIL import Image import imageio reader = imageio.get_reader(video_path, "ffmpeg") frame_count = 8 canny_edges = [Image.fromarray(reader.get_data(i)) for i in range(frame_count)]
Run
StableDiffusionControlNetPipeline
with custom trained DreamBooth modelimport torch from diffusers import StableDiffusionControlNetPipeline, ControlNetModel from diffusers.pipelines.text_to_video_synthesis.pipeline_text_to_video_zero import CrossFrameAttnProcessor # set model id to custom model model_id = "PAIR/text2video-zero-controlnet-canny-avatar" controlnet = ControlNetModel.from_pretrained("lllyasviel/sd-controlnet-canny", torch_dtype=torch.float16) pipe = StableDiffusionControlNetPipeline.from_pretrained( model_id, controlnet=controlnet, torch_dtype=torch.float16 ).to("cuda") # Set the attention processor pipe.unet.set_attn_processor(CrossFrameAttnProcessor(batch_size=2)) pipe.controlnet.set_attn_processor(CrossFrameAttnProcessor(batch_size=2)) # fix latents for all frames latents = torch.randn((1, 4, 64, 64), device="cuda", dtype=torch.float16).repeat(len(canny_edges), 1, 1, 1) prompt = "oil painting of a beautiful girl avatar style" result = pipe(prompt=[prompt] * len(canny_edges), image=canny_edges, latents=latents).images imageio.mimsave("video.mp4", result, fps=4)
You can filter out some available DreamBooth-trained models with this link.
Make sure to check out the Schedulers guide to learn how to explore the tradeoff between scheduler speed and quality, and see the reuse components across pipelines section to learn how to efficiently load the same components into multiple pipelines.
TextToVideoZeroPipeline
class diffusers.TextToVideoZeroPipeline
< source >( vae: AutoencoderKL text_encoder: CLIPTextModel tokenizer: CLIPTokenizer unet: UNet2DConditionModel scheduler: KarrasDiffusionSchedulers safety_checker: StableDiffusionSafetyChecker feature_extractor: CLIPImageProcessor requires_safety_checker: bool = True )
Parameters
- vae (AutoencoderKL) — Variational Auto-Encoder (VAE) Model to encode and decode images to and from latent representations.
- text_encoder (
CLIPTextModel
) — Frozen text-encoder (clip-vit-large-patch14). - tokenizer (
CLIPTokenizer
) — A CLIPTokenizer to tokenize text. - unet (UNet2DConditionModel) — A UNet3DConditionModel to denoise the encoded video latents.
- scheduler (SchedulerMixin) —
A scheduler to be used in combination with
unet
to denoise the encoded image latents. Can be one of DDIMScheduler, LMSDiscreteScheduler, or PNDMScheduler. - safety_checker (
StableDiffusionSafetyChecker
) — Classification module that estimates whether generated images could be considered offensive or harmful. Please refer to the model card for more details about a model’s potential harms. - feature_extractor (
CLIPImageProcessor
) — ACLIPImageProcessor
to extract features from generated images; used as inputs to thesafety_checker
.
Pipeline for zero-shot text-to-video generation using Stable Diffusion.
This model inherits from DiffusionPipeline. Check the superclass documentation for the generic methods implemented for all pipelines (downloading, saving, running on a particular device, etc.).
__call__
< source >( prompt: typing.Union[str, typing.List[str]] video_length: typing.Optional[int] = 8 height: typing.Optional[int] = None width: typing.Optional[int] = None num_inference_steps: int = 50 guidance_scale: float = 7.5 negative_prompt: typing.Union[str, typing.List[str], NoneType] = None num_videos_per_prompt: typing.Optional[int] = 1 eta: float = 0.0 generator: typing.Union[torch._C.Generator, typing.List[torch._C.Generator], NoneType] = None latents: typing.Optional[torch.Tensor] = None motion_field_strength_x: float = 12 motion_field_strength_y: float = 12 output_type: typing.Optional[str] = 'tensor' return_dict: bool = True callback: typing.Optional[typing.Callable[[int, int, torch.Tensor], NoneType]] = None callback_steps: typing.Optional[int] = 1 t0: int = 44 t1: int = 47 frame_ids: typing.Optional[typing.List[int]] = None ) → TextToVideoPipelineOutput
Parameters
- prompt (
str
orList[str]
, optional) — The prompt or prompts to guide image generation. If not defined, you need to passprompt_embeds
. - video_length (
int
, optional, defaults to 8) — The number of generated video frames. - height (
int
, optional, defaults toself.unet.config.sample_size * self.vae_scale_factor
) — The height in pixels of the generated image. - width (
int
, optional, defaults toself.unet.config.sample_size * self.vae_scale_factor
) — The width in pixels of the generated image. - 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. - guidance_scale (
float
, optional, defaults to 7.5) — A higher guidance scale value encourages the model to generate images closely linked to the textprompt
at the expense of lower image quality. Guidance scale is enabled whenguidance_scale > 1
. - negative_prompt (
str
orList[str]
, optional) — The prompt or prompts to guide what to not include in video generation. If not defined, you need to passnegative_prompt_embeds
instead. Ignored when not using guidance (guidance_scale < 1
). - num_videos_per_prompt (
int
, optional, defaults to 1) — The number of videos to generate per prompt. - eta (
float
, optional, defaults to 0.0) — Corresponds to parameter eta (η) from the DDIM paper. Only applies to the DDIMScheduler, and is ignored in other schedulers. - generator (
torch.Generator
orList[torch.Generator]
, optional) — Atorch.Generator
to make generation deterministic. - latents (
torch.Tensor
, optional) — Pre-generated noisy latents sampled from a Gaussian distribution, to be used as inputs for video generation. Can be used to tweak the same generation with different prompts. If not provided, a latents tensor is generated by sampling using the supplied randomgenerator
. - output_type (
str
, optional, defaults to"np"
) — The output format of the generated video. Choose between"latent"
and"np"
. - return_dict (
bool
, optional, defaults toTrue
) — Whether or not to return a TextToVideoPipelineOutput instead of a plain tuple. - callback (
Callable
, optional) — A function that calls everycallback_steps
steps during inference. The function is called with the following arguments:callback(step: int, timestep: int, latents: torch.Tensor)
. - callback_steps (
int
, optional, defaults to 1) — The frequency at which thecallback
function is called. If not specified, the callback is called at every step. - motion_field_strength_x (
float
, optional, defaults to 12) — Strength of motion in generated video along x-axis. See the paper, Sect. 3.3.1. - motion_field_strength_y (
float
, optional, defaults to 12) — Strength of motion in generated video along y-axis. See the paper, Sect. 3.3.1. - t0 (
int
, optional, defaults to 44) — Timestep t0. Should be in the range [0, num_inference_steps - 1]. See the paper, Sect. 3.3.1. - t1 (
int
, optional, defaults to 47) — Timestep t0. Should be in the range [t0 + 1, num_inference_steps - 1]. See the paper, Sect. 3.3.1. - frame_ids (
List[int]
, optional) — Indexes of the frames that are being generated. This is used when generating longer videos chunk-by-chunk.
Returns
The output contains a ndarray
of the generated video, when output_type
!= "latent"
, otherwise a
latent code of generated videos and a list of bool
s indicating whether the corresponding generated
video contains “not-safe-for-work” (nsfw) content..
The call function to the pipeline for generation.
backward_loop
< source >( latents timesteps prompt_embeds guidance_scale callback callback_steps num_warmup_steps extra_step_kwargs cross_attention_kwargs = None ) → latents
Parameters
- latents — Latents at time timesteps[0].
- timesteps — Time steps along which to perform backward process.
- prompt_embeds — Pre-generated text embeddings.
- guidance_scale —
A higher guidance scale value encourages the model to generate images closely linked to the text
prompt
at the expense of lower image quality. Guidance scale is enabled whenguidance_scale > 1
. - callback (
Callable
, optional) — A function that calls everycallback_steps
steps during inference. The function is called with the following arguments:callback(step: int, timestep: int, latents: torch.Tensor)
. - callback_steps (
int
, optional, defaults to 1) — The frequency at which thecallback
function is called. If not specified, the callback is called at every step. - extra_step_kwargs — Extra_step_kwargs.
- cross_attention_kwargs —
A kwargs dictionary that if specified is passed along to the
AttentionProcessor
as defined inself.processor
. - num_warmup_steps — number of warmup steps.
Returns
latents
Latents of backward process output at time timesteps[-1].
Perform backward process given list of time steps.
encode_prompt
< source >( prompt device num_images_per_prompt do_classifier_free_guidance negative_prompt = None prompt_embeds: typing.Optional[torch.Tensor] = None negative_prompt_embeds: typing.Optional[torch.Tensor] = None lora_scale: typing.Optional[float] = None clip_skip: typing.Optional[int] = None )
Parameters
- prompt (
str
orList[str]
, optional) — prompt to be encoded - device — (
torch.device
): torch device - num_images_per_prompt (
int
) — number of images that should be generated per prompt - do_classifier_free_guidance (
bool
) — whether to use classifier free guidance or not - negative_prompt (
str
orList[str]
, optional) — The prompt or prompts not to guide the image generation. If not defined, one has to passnegative_prompt_embeds
instead. Ignored when not using guidance (i.e., ignored ifguidance_scale
is less than1
). - prompt_embeds (
torch.Tensor
, 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 fromprompt
input argument. - negative_prompt_embeds (
torch.Tensor
, optional) — Pre-generated negative text embeddings. Can be used to easily tweak text inputs, e.g. prompt weighting. If not provided, negative_prompt_embeds will be generated fromnegative_prompt
input argument. - lora_scale (
float
, optional) — A LoRA scale that will be applied to all LoRA layers of the text encoder if LoRA layers are loaded. - 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.
Encodes the prompt into text encoder hidden states.
forward_loop
< source >( x_t0 t0 t1 generator ) → x_t1
Parameters
- x_t0 — Latent code at time t0.
- t0 — Timestep at t0.
- t1 — Timestamp at t1.
- generator (
torch.Generator
orList[torch.Generator]
, optional) — Atorch.Generator
to make generation deterministic.
Returns
x_t1
Forward process applied to x_t0 from time t0 to t1.
Perform DDPM forward process from time t0 to t1. This is the same as adding noise with corresponding variance.
TextToVideoZeroSDXLPipeline
class diffusers.TextToVideoZeroSDXLPipeline
< source >( vae: AutoencoderKL text_encoder: CLIPTextModel text_encoder_2: CLIPTextModelWithProjection tokenizer: CLIPTokenizer tokenizer_2: CLIPTokenizer unet: UNet2DConditionModel scheduler: KarrasDiffusionSchedulers image_encoder: CLIPVisionModelWithProjection = None feature_extractor: CLIPImageProcessor = None force_zeros_for_empty_prompt: bool = True add_watermarker: typing.Optional[bool] = None )
Parameters
- vae (AutoencoderKL) — Variational Auto-Encoder (VAE) Model to encode and decode images to and from latent representations.
- text_encoder (
CLIPTextModel
) — Frozen text-encoder. Stable Diffusion XL uses the text portion of CLIP, specifically the clip-vit-large-patch14 variant. - text_encoder_2 (
CLIPTextModelWithProjection
) — Second frozen text-encoder. Stable Diffusion XL uses the text and pool portion of CLIP, specifically the laion/CLIP-ViT-bigG-14-laion2B-39B-b160k variant. - tokenizer (
CLIPTokenizer
) — Tokenizer of class CLIPTokenizer. - tokenizer_2 (
CLIPTokenizer
) — Second Tokenizer of class CLIPTokenizer. - unet (UNet2DConditionModel) — Conditional U-Net architecture to denoise the encoded image latents.
- scheduler (SchedulerMixin) —
A scheduler to be used in combination with
unet
to denoise the encoded image latents. Can be one of DDIMScheduler, LMSDiscreteScheduler, or PNDMScheduler.
Pipeline for zero-shot text-to-video generation using Stable Diffusion XL.
This model inherits from DiffusionPipeline. Check the superclass documentation for the generic methods implemented for all pipelines (downloading, saving, running on a particular device, etc.).
__call__
< source >( prompt: typing.Union[str, typing.List[str]] prompt_2: typing.Union[str, typing.List[str], NoneType] = None video_length: typing.Optional[int] = 8 height: typing.Optional[int] = None width: typing.Optional[int] = None num_inference_steps: int = 50 denoising_end: typing.Optional[float] = None guidance_scale: float = 7.5 negative_prompt: typing.Union[str, typing.List[str], NoneType] = None negative_prompt_2: typing.Union[str, typing.List[str], NoneType] = None num_videos_per_prompt: typing.Optional[int] = 1 eta: float = 0.0 generator: typing.Union[torch._C.Generator, typing.List[torch._C.Generator], NoneType] = None frame_ids: typing.Optional[typing.List[int]] = None prompt_embeds: typing.Optional[torch.Tensor] = None negative_prompt_embeds: typing.Optional[torch.Tensor] = None pooled_prompt_embeds: typing.Optional[torch.Tensor] = None negative_pooled_prompt_embeds: typing.Optional[torch.Tensor] = None latents: typing.Optional[torch.Tensor] = None motion_field_strength_x: float = 12 motion_field_strength_y: float = 12 output_type: typing.Optional[str] = 'tensor' return_dict: bool = True callback: typing.Optional[typing.Callable[[int, int, torch.Tensor], NoneType]] = None callback_steps: int = 1 cross_attention_kwargs: typing.Optional[typing.Dict[str, typing.Any]] = None guidance_rescale: float = 0.0 original_size: typing.Optional[typing.Tuple[int, int]] = None crops_coords_top_left: typing.Tuple[int, int] = (0, 0) target_size: typing.Optional[typing.Tuple[int, int]] = None t0: int = 44 t1: int = 47 )
Parameters
- prompt (
str
orList[str]
, optional) — The prompt or prompts to guide the image generation. If not defined, one has to passprompt_embeds
. instead. - prompt_2 (
str
orList[str]
, optional) — The prompt or prompts to be sent to thetokenizer_2
andtext_encoder_2
. If not defined,prompt
is used in both text-encoders - video_length (
int
, optional, defaults to 8) — The number of generated video frames. - height (
int
, optional, defaults to self.unet.config.sample_size * self.vae_scale_factor) — The height in pixels of the generated image. - width (
int
, optional, defaults to self.unet.config.sample_size * self.vae_scale_factor) — The width in pixels of the generated image. - 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. - denoising_end (
float
, optional) — When specified, determines the fraction (between 0.0 and 1.0) of the total denoising process to be completed before it is intentionally prematurely terminated. As a result, the returned sample will still retain a substantial amount of noise as determined by the discrete timesteps selected by the scheduler. The denoising_end parameter should ideally be utilized when this pipeline forms a part of a “Mixture of Denoisers” multi-pipeline setup, as elaborated in Refining the Image Output - guidance_scale (
float
, optional, defaults to 7.5) — Guidance scale as defined in Classifier-Free Diffusion Guidance.guidance_scale
is defined asw
of equation 2. of Imagen Paper. Guidance scale is enabled by settingguidance_scale > 1
. Higher guidance scale encourages to generate images that are closely linked to the textprompt
, usually at the expense of lower image quality. - negative_prompt (
str
orList[str]
, optional) — The prompt or prompts not to guide the image generation. If not defined, one has to passnegative_prompt_embeds
instead. Ignored when not using guidance (i.e., ignored ifguidance_scale
is less than1
). - negative_prompt_2 (
str
orList[str]
, optional) — The prompt or prompts not to guide the image generation to be sent totokenizer_2
andtext_encoder_2
. If not defined,negative_prompt
is used in both text-encoders - num_videos_per_prompt (
int
, optional, defaults to 1) — The number of videos to generate per prompt. - eta (
float
, optional, defaults to 0.0) — Corresponds to parameter eta (η) in the DDIM paper: https://arxiv.org/abs/2010.02502. Only applies to schedulers.DDIMScheduler, will be ignored for others. - generator (
torch.Generator
orList[torch.Generator]
, optional) — One or a list of torch generator(s) to make generation deterministic. - frame_ids (
List[int]
, optional) — Indexes of the frames that are being generated. This is used when generating longer videos chunk-by-chunk. - prompt_embeds (
torch.Tensor
, 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 fromprompt
input argument. - negative_prompt_embeds (
torch.Tensor
, optional) — Pre-generated negative text embeddings. Can be used to easily tweak text inputs, e.g. prompt weighting. If not provided, negative_prompt_embeds will be generated fromnegative_prompt
input argument. - pooled_prompt_embeds (
torch.Tensor
, 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 fromprompt
input argument. - negative_pooled_prompt_embeds (
torch.Tensor
, optional) — Pre-generated negative pooled text embeddings. Can be used to easily tweak text inputs, e.g. prompt weighting. If not provided, pooled negative_prompt_embeds will be generated fromnegative_prompt
input argument. - latents (
torch.Tensor
, 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 randomgenerator
. - motion_field_strength_x (
float
, optional, defaults to 12) — Strength of motion in generated video along x-axis. See the paper, Sect. 3.3.1. - motion_field_strength_y (
float
, optional, defaults to 12) — Strength of motion in generated video along y-axis. See the paper, Sect. 3.3.1. - output_type (
str
, optional, defaults to"pil"
) — The output format of the generate image. Choose between PIL:PIL.Image.Image
ornp.array
. - return_dict (
bool
, optional, defaults toTrue
) — Whether or not to return a~pipelines.stable_diffusion_xl.StableDiffusionXLPipelineOutput
instead of a plain tuple. - callback (
Callable
, optional) — A function that will be called everycallback_steps
steps during inference. The function will be called with the following arguments:callback(step: int, timestep: int, latents: torch.Tensor)
. - callback_steps (
int
, optional, defaults to 1) — The frequency at which thecallback
function will be called. If not specified, the callback will be called at every step. - cross_attention_kwargs (
dict
, optional) — A kwargs dictionary that if specified is passed along to theAttentionProcessor
as defined underself.processor
in diffusers.cross_attention. - guidance_rescale (
float
, optional, defaults to 0.7) — Guidance rescale factor proposed by Common Diffusion Noise Schedules and Sample Steps are Flawedguidance_scale
is defined asφ
in equation 16. of Common Diffusion Noise Schedules and Sample Steps are Flawed. Guidance rescale factor should fix overexposure when using zero terminal SNR. - original_size (
Tuple[int]
, optional, defaults to (1024, 1024)) — Iforiginal_size
is not the same astarget_size
the image will appear to be down- or upsampled.original_size
defaults to(width, height)
if not specified. Part of SDXL’s micro-conditioning as explained in section 2.2 of https://huggingface.co./papers/2307.01952. - crops_coords_top_left (
Tuple[int]
, optional, defaults to (0, 0)) —crops_coords_top_left
can be used to generate an image that appears to be “cropped” from the positioncrops_coords_top_left
downwards. Favorable, well-centered images are usually achieved by settingcrops_coords_top_left
to (0, 0). Part of SDXL’s micro-conditioning as explained in section 2.2 of https://huggingface.co./papers/2307.01952. - target_size (
Tuple[int]
, optional, defaults to (1024, 1024)) — For most cases,target_size
should be set to the desired height and width of the generated image. If not specified it will default to(width, height)
. Part of SDXL’s micro-conditioning as explained in section 2.2 of https://huggingface.co./papers/2307.01952. - t0 (
int
, optional, defaults to 44) — Timestep t0. Should be in the range [0, num_inference_steps - 1]. See the paper, Sect. 3.3.1. - t1 (
int
, optional, defaults to 47) — Timestep t0. Should be in the range [t0 + 1, num_inference_steps - 1]. See the paper, Sect. 3.3.1.
Function invoked when calling the pipeline for generation.
backward_loop
< source >( latents timesteps prompt_embeds guidance_scale callback callback_steps num_warmup_steps extra_step_kwargs add_text_embeds add_time_ids cross_attention_kwargs = None guidance_rescale: float = 0.0 ) → latents
Parameters
- latents — Latents at time timesteps[0].
- timesteps — Time steps along which to perform backward process.
- prompt_embeds — Pre-generated text embeddings.
- guidance_scale —
A higher guidance scale value encourages the model to generate images closely linked to the text
prompt
at the expense of lower image quality. Guidance scale is enabled whenguidance_scale > 1
. - callback (
Callable
, optional) — A function that calls everycallback_steps
steps during inference. The function is called with the following arguments:callback(step: int, timestep: int, latents: torch.Tensor)
. - callback_steps (
int
, optional, defaults to 1) — The frequency at which thecallback
function is called. If not specified, the callback is called at every step. - extra_step_kwargs — Extra_step_kwargs.
- cross_attention_kwargs —
A kwargs dictionary that if specified is passed along to the
AttentionProcessor
as defined inself.processor
. - num_warmup_steps — number of warmup steps.
Returns
latents
latents of backward process output at time timesteps[-1]
Perform backward process given list of time steps
encode_prompt
< source >( prompt: str prompt_2: typing.Optional[str] = None device: typing.Optional[torch.device] = None num_images_per_prompt: int = 1 do_classifier_free_guidance: bool = True negative_prompt: typing.Optional[str] = None negative_prompt_2: typing.Optional[str] = None prompt_embeds: typing.Optional[torch.Tensor] = None negative_prompt_embeds: typing.Optional[torch.Tensor] = None pooled_prompt_embeds: typing.Optional[torch.Tensor] = None negative_pooled_prompt_embeds: typing.Optional[torch.Tensor] = None lora_scale: typing.Optional[float] = None clip_skip: typing.Optional[int] = None )
Parameters
- prompt (
str
orList[str]
, optional) — prompt to be encoded - prompt_2 (
str
orList[str]
, optional) — The prompt or prompts to be sent to thetokenizer_2
andtext_encoder_2
. If not defined,prompt
is used in both text-encoders - device — (
torch.device
): torch device - num_images_per_prompt (
int
) — number of images that should be generated per prompt - do_classifier_free_guidance (
bool
) — whether to use classifier free guidance or not - negative_prompt (
str
orList[str]
, optional) — The prompt or prompts not to guide the image generation. If not defined, one has to passnegative_prompt_embeds
instead. Ignored when not using guidance (i.e., ignored ifguidance_scale
is less than1
). - negative_prompt_2 (
str
orList[str]
, optional) — The prompt or prompts not to guide the image generation to be sent totokenizer_2
andtext_encoder_2
. If not defined,negative_prompt
is used in both text-encoders - prompt_embeds (
torch.Tensor
, 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 fromprompt
input argument. - negative_prompt_embeds (
torch.Tensor
, optional) — Pre-generated negative text embeddings. Can be used to easily tweak text inputs, e.g. prompt weighting. If not provided, negative_prompt_embeds will be generated fromnegative_prompt
input argument. - pooled_prompt_embeds (
torch.Tensor
, 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 fromprompt
input argument. - negative_pooled_prompt_embeds (
torch.Tensor
, optional) — Pre-generated negative pooled text embeddings. Can be used to easily tweak text inputs, e.g. prompt weighting. If not provided, pooled negative_prompt_embeds will be generated fromnegative_prompt
input argument. - lora_scale (
float
, optional) — A lora scale that will be applied to all LoRA layers of the text encoder if LoRA layers are loaded. - 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.
Encodes the prompt into text encoder hidden states.
forward_loop
< source >( x_t0 t0 t1 generator ) → x_t1
Parameters
- x_t0 — Latent code at time t0.
- t0 — Timestep at t0.
- t1 — Timestamp at t1.
- generator (
torch.Generator
orList[torch.Generator]
, optional) — Atorch.Generator
to make generation deterministic.
Returns
x_t1
Forward process applied to x_t0 from time t0 to t1.
Perform DDPM forward process from time t0 to t1. This is the same as adding noise with corresponding variance.
TextToVideoPipelineOutput
class diffusers.pipelines.text_to_video_synthesis.pipeline_text_to_video_zero.TextToVideoPipelineOutput
< source >( images: typing.Union[typing.List[PIL.Image.Image], numpy.ndarray] nsfw_content_detected: typing.Optional[typing.List[bool]] )
Parameters
- images (
[List[PIL.Image.Image]
,np.ndarray
]) — List of denoised PIL images of lengthbatch_size
or NumPy array of shape(batch_size, height, width, num_channels)
. - nsfw_content_detected (
[List[bool]]
) — List indicating whether the corresponding generated image contains “not-safe-for-work” (nsfw) content orNone
if safety checking could not be performed.
Output class for zero-shot text-to-video pipeline.