Research & Papers

Diffusion models emerge as the foundation for video generation research

Google + OpenAISource: Lilian Weng11/04/2024, 21:00
Diffusion models, which learn to progressively remove noise from data, are being successfully adapted for video generation. This approach is particularly promising because it extends methods already proven in image synthesis to the more complex challenge of generating coherent videos. Two main strategies have emerged: building entirely new architectures specialized for spatiotemporal processing, or extending pre-trained image models with additional temporal components. OpenAI's Sora exemplifies the former approach with a Transformer architecture operating on spacetime patches, while Make-A-Video and Stable Video Diffusion demonstrate the viability of the latter strategy by leveraging prior knowledge from image models. Video quality depends on several sophisticated technical components. Spatial upsampling layers increase resolution and frame rates, spatiotemporal attention mechanisms maintain visual consistency across consecutive frames, and careful curation of training data significantly improves final results. Google's Imagen Video achieves high-resolution output (up to 1280x768 pixels at 24 fps) by employing a cascade of multiple diffusion models and progressive distillation techniques to accelerate inference. Dataset quality proves critical, with researchers filtering clips based on optical flow, text presence, and aesthetic scores. Practical applications are already expanding beyond pure video generation. Models like Runway's Gen-1 enable editing of existing videos through text commands, opening possibilities for background changes, style transfer, and object manipulation. Remaining technical challenges include eliminating visual artifacts such as flickering, maintaining visual coherence over long sequences, reducing processing time, and improving overall computational efficiency. The rapid advancement of the field suggests these challenges are increasingly tractable.
Diffusion models emerge as the foundation for video generation research — lupAI