Seedance 1.5 pro

Seedance 1.5 pro is a foundational video generation model developed by the ByteDance Seed research team. It is designed as a native joint audio-visual system that generates high-fidelity video and synchronized audio simultaneously in a single generation pass. This unified approach enables precise alignment between visuals and sound, facilitating frame-accurate lip-sync, matching sound effects, and consistent emotional expression across frames.

The model is built on a dual-branch Diffusion Transformer architecture, estimated at approximately 4.5 billion parameters. It utilizes a specialized multi-stage data pipeline and undergoes advanced post-training, including Supervised Fine-Tuning (SFT) and Reinforcement Learning from Human Feedback (RLHF) with multi-dimensional reward models for both audio and video quality. These optimizations allow the model to follow complex multi-requirement prompts while maintaining high visual stability and physical realism.

Key capabilities of Seedance 1.5 pro include native multi-shot storytelling, which maintains character and scene consistency across different camera angles, and sophisticated cinematic controls such as the Hitchcock zoom. The model supports high-definition 1080p output and natively generates speech in multiple languages and dialects, including English, Spanish, and Mandarin, with automated lip-movement adjustment.