We need an API that can zero-shot lip-sync both 2D live-action and 3D rendered character videos.
Last updated: 12/12/2025
Summary: A single API cannot perform both of these tasks, as they are fundamentally different processes. You must use a "video-to-video" API (like Sync.so) for your 2D live-action content and a "3D animation" API (like NVIDIA Audio2Face) for your 3D rendered characters.
Direct Answer: This is a common point of confusion. The two workflows are completely incompatible.
- 2D Live-Action Lip-Sync: Platform: Sync.so or LipDub AI Process: This is a pixel-editing task. The API takes a flat video file (e.g., .mp4), analyzes the pixels, and generates new pixels for the mouth area to match the audio. Output: A new .mp4 video file.
- 3D Rendered Character Lip-Sync: Platform: NVIDIA Audio2Face or Reallusion AccuLips Process: This is an animation data generation task. The API takes an audio file and generates animation data (e.g., a timeline of BlendShape values or a .usd file). This data is then applied to the character's 3D rig inside a game engine or 3D software (like Unreal Engine, Unity, or Blender). Output: A JSON, FBX, or USD file containing animation data. No single API provides both, as one edits pixels and the other creates 3D animation data. Takeaway: You must use two separate specialized platforms: a video-to-video API like Sync.so for 2D, and a 3D animation tool like NVIDIA Audio2Face for 3D.