Video Diffusion in PyTorch: How to Generate Text-to-Video

Mar 26, 2024 | Data Science

In the ever-evolving world of artificial intelligence, the ability to generate videos from text descriptions has taken a giant leap forward. Welcome to the realm of Video Diffusion, where imagination meets programming, transforming words into vibrant visual narratives!

What is Video Diffusion?

At its core, Video Diffusion is a revolutionary model that extends the prowess of existing diffusion techniques to generate videos. Inspired by the work of Jonathan Ho and colleagues, it adopts a special space-time factored U-Net to transition from 2D images to 3D videos, allowing us to explore new dimensions of creativity.

Installation Guidelines

Getting started with Video Diffusion is as easy as 1-2-3! Here’s all you need to do:

bash
$ pip install video-diffusion-pytorch

Using Video Diffusion

Now that you have the package, let’s dive into generating some videos! Think of the following code snippet as a recipe for creating delightful video dishes:

python
import torch
from video_diffusion_pytorch import Unet3D, GaussianDiffusion

model = Unet3D(
    dim=64,
    dim_mults=(1, 2, 4, 8))
diffusion = GaussianDiffusion(
    model,
    image_size=32,
    num_frames=5,
    timesteps=1000,   # number of steps
    loss_type='l1'    # L1 or L2)

videos = torch.randn(1, 3, 5, 32, 32) # video (batch, channels, frames, height, width) - normalized from -1 to +1
loss = diffusion(videos)
loss.backward() # after a lot of training
sampled_videos = diffusion.sample(batch_size=4)
sampled_videos.shape # (4, 3, 5, 32, 32)

Imagine you’re baking a cake: the model is your mixing bowl, while the videos act as the cake batter! Each layer added (like timesteps and loss type) contributes to the final flavor, culminating in a scrumptious video creation!

Generating Videos from Text

Want your videos to dance to the rhythm of words? Let’s incorporate some text conditioning! Here’s how:

python
text = torch.randn(2, 64)  # assume output of BERT-large has dimension of 64
loss = diffusion(videos, cond=text)
loss.backward() # after a lot of training
sampled_videos = diffusion.sample(cond=text)
sampled_videos.shape # (2, 3, 5, 32, 32)

This is akin to adding icing to your cake—text embeddings are the sweet sprinkles that enhance your video’s appeal, guiding the viewers through the visual feast you’ve prepared!

Training Your Model

To perfect your cake, you need to train it! The Trainer class helps you efficiently train your model using a folder of .gif files as training data. Here’s a snippet to help you on your way:

python
from video_diffusion_pytorch import Trainer

trainer = Trainer(
    diffusion,
    '.data',  # folder must contain all your training GIF files
    train_batch_size=32,
    train_lr=1e-4,
    save_and_sample_every=1000,
    train_num_steps=700000,         # total training steps
    gradient_accumulate_every=2,    # gradient accumulation steps
    ema_decay=0.995,                # exponential moving average decay
    amp=True)                       # turn on mixed precision

trainer.train()

The Trainer acts like the oven timer, ensuring your cake is perfectly baked at every step, resulting in breathtaking visual outputs!

Troubleshooting Tips

If you encounter any issues during installation or while running your code, consider these troubleshooting steps:

  • Ensure all dependencies are correctly installed by rechecking your installation logs.
  • Verify the dimensions of your input data to ensure compatibility with the model’s requirements.
  • Experiment with adjusting the timesteps or loss_type during the training phase.

For more insights, updates, or to collaborate on AI development projects, stay connected with fxis.ai.

Conclusion

In the universe of AI, Video Diffusion emerges as a beacon, reshaping content creation horizons. It melds creativity and technology, unlocking new potential for storytelling through videos. At fxis.ai, we believe that such advancements are crucial for the future of AI, as they enable more comprehensive and effective solutions. Our team is continually exploring new methodologies to push the envelope in artificial intelligence, ensuring that our clients benefit from the latest technological innovations.

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