Speed by Simplicity: A Single-Stream Architecture for Fast Audio-Video Generative Foundation Model
Abstract
We present daVinci-MagiHuman, an open-source audio-video generative foundation model for human-centric generation. daVinci-MagiHuman jointly generates synchronized video and audio using a single-stream Transformer that processes text, video, and audio within a unified token sequence via self-attention only. This single-stream design avoids the complexity of multi-stream or cross-attention architectures while remaining easy to optimize with standard training and inference infrastructure. The model is particularly strong in human-centric scenarios, producing expressive facial performance, natural speech-expression coordination, realistic body motion, and precise audio-video synchronization. It supports multilingual spoken generation across Chinese (Mandarin and Cantonese), English, Japanese, Korean, German, and French. For efficient inference, we combine the single-stream backbone with model distillation, latent-space super-resolution, and a Turbo VAE decoder, enabling generation of a 5-second 256p video in 2 seconds on a single H100 GPU. In automatic evaluation, daVinci-MagiHuman achieves the highest visual quality and text alignment among leading open models, along with the lowest word error rate (14.60%) for speech intelligibility. In pairwise human evaluation, it achieves win rates of 80.0% against Ovi 1.1 and 60.9% against LTX 2.3 over 2000 comparisons. We open-source the complete model stack, including the base model, the distilled model, the super-resolution model, and the inference codebase.
Keywords
Cite
@article{arxiv.2603.21986,
title = {Speed by Simplicity: A Single-Stream Architecture for Fast Audio-Video Generative Foundation Model},
author = {SII-GAIR and Sand. ai and : and Ethan Chern and Hansi Teng and Hanwen Sun and Hao Wang and Hong Pan and Hongyu Jia and Jiadi Su and Jin Li and Junjie Yu and Lijie Liu and Lingzhi Li and Lyumanshan Ye and Min Hu and Qiangang Wang and Quanwei Qi and Steffi Chern and Tao Bu and Taoran Wang and Teren Xu and Tianning Zhang and Tiantian Mi and Weixian Xu and Wenqiang Zhang and Wentai Zhang and Xianping Yi and Xiaojie Cai and Xiaoyang Kang and Yan Ma and Yixiu Liu and Yunbo Zhang and Yunpeng Huang and Yutong Lin and Zewei Tao and Zhaoliang Liu and Zheng Zhang and Zhiyao Cen and Zhixuan Yu and Zhongshu Wang and Zhulin Hu and Zijin Zhou and Zinan Guo and Yue Cao and Pengfei Liu},
journal= {arXiv preprint arXiv:2603.21986},
year = {2026}
}