Ishaan Chandratreya and David Charatan
MIT
MilliVid: Hierarchical Latents for Long-Range Consistency in Video Generation
Ishaan Chandratreya and David Charatan · MIT
Video generative models have become increasingly powerful, but long-range consistency remains challenging to achieve because even a few dozen frames require impractically long transformer sequence lengths. We show that this issue can be mitigated by generating video using coarse-to-fine rollout within a multi-scale token space. Our approach is simple: first, we pre-train an autoencoder that compresses each frame into a hierarchy of tokens, with levels ranging from the typical latent resolution to only a handful of tokens per frame. The coarsest levels capture the most consequential information—such as scene layout and semantics—while finer levels add high-frequency appearance and texture. Then, we train a video diffusion model to generate these tokens using coarse-to-fine rollout. By carefully controlling the level of detail at which frames are generated and used as context during each rollout step, we are able to preserve long-range consistency in geometry and object permanence while spending less compute on the long-range consistency of less perceptually relevant details. We validate this approach using a custom dataset of long Minecraft videos, where it produces substantially more consistent rollouts compared to existing baselines
About the speaker
Ishaan Preetam Chandratreya is a Ph.D. student in Electrical Engineering and Computer Science at MIT, advised by Prof. Vincent Sitzmann and Prof. Phillip Isola. His research focuses on representation learning and generative modeling for video, and on algorithms that use these models for planning. He received his B.S. in Computer Science from Columbia University, where he worked with Prof. Carl Vondrick, and has interned at Toyota Research Institute and Rhoda AI working on related problems. His work is supported by an NSF Graduate Research Fellowship and an MIT Presidential Fellowship.
David Charatan is a PhD student at MIT, where he is advised by Vincent Sitzmann. His research focuses on 3D computer vision and generative models, spanning 3D reconstruction, differentiable rendering, camera pose estimation, and video generation. His most well-known work is pixelSplat, which was a best paper runner-up at CVPR 2024. While at MIT, he interned at Toyota Research Institute and Google DeepMind; before MIT, he worked as a research engineer at Common Sense Machines and earned an Sc.B. in computer engineering from Brown University