Zero-Shot Text-to-Video Generation
Overview
Text2Video-Zero: Text-to-Image Diffusion Models are Zero-Shot Video Generators by Levon Khachatryan, Andranik Movsisyan, Vahram Tadevosyan, Roberto Henschel, Zhangyang Wang, Shant Navasardyan, Humphrey Shi.
Our method Text2Video-Zero enables zero-shot video generation using either
- A textual prompt, or
- A prompt combined with guidance from poses or edges, or
- Video Instruct-Pix2Pix, i.e., instruction-guided video editing.
Results are temporally consistent and follow closely the guidance and textual prompts.
The abstract of the paper is the following:
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.
Resources:
Available Pipelines:
Pipeline | Tasks | Demo |
---|---|---|
TextToVideoZeroPipeline | Zero-shot Text-to-Video Generation | 🤗 Space |
Usage example
Text-To-Video
To generate a video from prompt, run the following python command
import torch
import imageio
from diffusers import TextToVideoZeroPipeline
model_id = "runwayml/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 an also generate longer videos by doing the processing in a chunk-by-chunk manner:
import torch
import imageio
from diffusers import TextToVideoZeroPipeline
import numpy as np
model_id = "runwayml/stable-diffusion-v1-5"
pipe = TextToVideoZeroPipeline.from_pretrained(model_id, torch_dtype=torch.float16).to("cuda")
seed = 0
video_length = 8
chunk_size = 4
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)
Text-To-Video with Pose Control
To generate a video from prompt with additional pose controlDownload 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 = "runwayml/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)
Text-To-Video with Edge Control
To generate a video from prompt with additional pose control, follow the 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.
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. Stable Diffusion uses the text portion of CLIP, specifically the clip-vit-large-patch14 variant. -
tokenizer (
CLIPTokenizer
) — 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. -
safety_checker (
StableDiffusionSafetyChecker
) — Classification module that estimates whether generated images could be considered offensive or harmful. Please, refer to the model card for details. -
feature_extractor (
CLIPImageProcessor
) — Model that extracts features from generated images to be used as inputs for thesafety_checker
.
Pipeline for zero-shot text-to-video generation using Stable Diffusion.
This model inherits from StableDiffusionPipeline. Check the superclass documentation for the generic methods the library implements for all the pipelines (such as downloading or 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.FloatTensor] = 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.Union[typing.Callable[[int, int, torch.FloatTensor], NoneType], NoneType] = None
callback_steps: typing.Optional[int] = 1
t0: int = 44
t1: int = 47
frame_ids: typing.Optional[typing.List[int]] = None
)
→
~pipelines.text_to_video_synthesis.TextToVideoPipelineOutput
Parameters
-
prompt (
str
orList[str]
, optional) — The prompt or prompts to guide the image generation. If not defined, one has to passprompt_embeds
. instead. -
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. -
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
). -
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. -
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 randomgenerator
. -
output_type (
str
, optional, defaults to"numpy"
) — The output format of the generated image. Choose between"latent"
and"numpy"
. -
return_dict (
bool
, optional, defaults toTrue
) — Whether or not to return a StableDiffusionPipelineOutput 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.FloatTensor)
. -
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. -
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
~pipelines.text_to_video_synthesis.TextToVideoPipelineOutput
The output contains a ndarray of the generated images, when output_type != ‘latent’, otherwise a latent
codes of generated image, and a list of bool
s denoting whether the corresponding generated image
likely represents “not-safe-for-work” (nsfw) content, according to the safety_checker
.
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 cross_attention_kwargs = None ) → latents
Parameters
-
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.FloatTensor)
. -
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. extra_step_kwargs — extra_step_kwargs. cross_attention_kwargs — cross_attention_kwargs. 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
forward_loop
< source >( x_t0 t0 t1 generator ) → x_t1
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.