VideoJAM: Joint Appearance-Motion Representations for Enhanced Motion
  Generation in Video Models
Authors: name: Hila Chefer, name: Uriel Singer, name: Amit Zohar, name: Yuval Kirstain, name: Adam Polyak, name: Yaniv Taigman, name: Lior Wolf, name: Shelly Sheynin

Despite tremendous recent progress, generative video models still struggle to
capture real-world motion, dynamics, and physics. We show that this limitation
arises from the conventional pixel reconstruction objective, which biases
models toward appearance fidelity at the expense of motion coherence. To
address this, we introduce VideoJAM, a novel framework that instills an
effective motion prior to video generators, by encouraging the model to learn a
joint appearance-motion representation. VideoJAM is composed of two
complementary units. During training, we extend the objective to predict both
the generated pixels and their corresponding motion from a single learned
representation. During inference, we introduce Inner-Guidance, a mechanism that
steers the generation toward coherent motion by leveraging the model's own
evolving motion prediction as a dynamic guidance signal. Notably, our framework
can be applied to any video model with minimal adaptations, requiring no
modifications to the training data or scaling of the model. VideoJAM achieves
state-of-the-art performance in motion coherence, surpassing highly competitive
proprietary models while also enhancing the perceived visual quality of the
generations. These findings emphasize that appearance and motion can be
complementary and, when effectively integrated, enhance both the visual quality
and the coherence of video generation. Project website:
https://hila-chefer.github.io/videojam-paper.github.io/