Hallo, a portrait image animation technology developed by Fudan University, utilizes diffusion models to generate realistic and dynamic portrait animations. Unlike traditional methods relying on parametric models for intermediate facial representations, Hallo adopts an end-to-end diffusion paradigm and introduces a hierarchical audio-driven visual synthesis module to enhance the alignment precision between audio input and visual output, including lip, facial expression, and pose movements. This technology offers adaptive control over facial expression and pose diversity, enabling more effective personalized customization for individuals of different identities.