Alibaba: HappyHorse 1.0Active

Happy Horse 1.0 is described as an open-source state-of-the-art AI video generator with native joint audio-video generation — meaning the Happy Horse AI video model produces video frames and the corresponding audio track (dialogue, ambient sound, Foley) together in a single forward pass, rather than generating silent video and dubbing it afterward. According to community-compiled architecture notes, the model is built around a 15-billion-parameter unified self-attention Transformer that processes text, image, video, and audio tokens within a single token sequence. It is reportedly built without dedicated cross-attention branches and without a separate audio module. Combined with DMD-2 distillation, the distilled variant is reported to generate 1080p video in roughly 38 seconds on an NVIDIA H100, using only 8 denoising steps without classifier-free guidance.