HappyHorse-1.0 is a large-scale video generation model developed by Alibaba's ATH (Alibaba Token Hub) unit. Released in April 2026, the model gained rapid prominence by topping several global leaderboards for video synthesis, including the Artificial Analysis Video Arena. It is distinguished by its ability to generate high-fidelity video content with natively synchronized audio in a single inference pass, rather than layering audio over pre-generated video.
The model's architecture is built on a unified single-stream Transformer featuring approximately 15 billion parameters and 40 layers. This design allows text, image, and audio tokens to be processed within a single joint sequence, facilitating superior temporal coherence and precise synchronization between visual motion and sound. This approach is particularly effective for complex tasks such as multi-shot narrative continuity and realistic physical interactions within generated scenes.
Technical Features and Capabilities
HappyHorse-1.0 supports high-definition output up to 1080p and incorporates DMD-2 distillation to optimize inference speeds. This allows the model to generate a 5-second 1080p video in approximately 38 seconds on a single NVIDIA H100 GPU using an 8-step denoising process. It natively supports lip-synchronization for seven languages: English, Mandarin, Cantonese, Japanese, Korean, German, and French, maintaining an industry-leading word error rate (WER).
Key capabilities include robust text-to-video and image-to-video synthesis with strong adherence to complex cinematic prompts. The model is released under an open-source license for both research and commercial use, intended to provide a high-performance open alternative to proprietary video generation systems. Its development was led by the Alibaba-ATH innovation unit, which focuses on integrating multimodal generation with new interaction paradigms.