H3 关键帧驱动的连续运镜（图生视频） · 4 秒快测H3 keyframe-driven continuous motion (image-conditioned) · 4s quick test

拿一张定好的关键帧生成有声视频。提示词开头用一行把参考图绑定到目标视频的具体时间点，正文只描述从这一帧出发的连续运动——这是让画面不跑偏的关键，比在正文里反复描述图片内容有效。【4 秒快测版】内容与原版一致，压到 4 秒用于试参数、试素材、试机器，不用于出成片。

Grow a sound-on video out of one locked keyframe: the prompt binds the frame to a timecode and describes only the motion from there. [4s quick test] Same content as the full-length version, cut to 4 seconds for checking parameters, assets and hardware — not for final delivery.